Friday, July 29, 2005

Part II

Department of Labor Mine Safety and Health Administration

30 CFR Parts 56, 57, and 71 Asbestos Exposure Limit; Proposed Rule

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00001 Fmt 4717 Sfmt 4717 E:\FR\FM\29JYP2.SGM 29JYP2 43950 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

DEPARTMENT OF LABOR documents in the Federal Register, E. Section 71.701(c) and (d): Sampling; subscribe to our list serve at http:// General Requirements Mine Safety and Health Administration www.msha.gov/subscriptions/ VIII. Regulatory Analyses subscribe.aspx. A. Executive Order (E.O.) 12866 30 CFR Parts 56, 57, and 71 B. Feasibility FOR FURTHER INFORMATION CONTACT: C. Alternatives Considered RIN: 1219–AB24 Rebecca J. Smith at 202–693–9440 D. Regulatory Flexibility Analysis (RFA) (Voice), 202–693–9441 (Fax), or and Small Business Regulatory Asbestos Exposure Limit mailto:[email protected] (E-mail). Enforcement Fairness Act (SBREFA) E. Other Regulatory Considerations AGENCY: Mine Safety and Health SUPPLEMENTARY INFORMATION: IX. Copy of the OSHA Reference Method Administration (MSHA), Labor. I. Introduction (ORM) ACTION: Proposed rule; notice of public X. References Cited in the Preamble A. Outline of Preamble hearings. B. Dates and Locations for Public We are including the following Hearings SUMMARY: We (MSHA) are proposing to outline to help you find information in revise our existing health standards for this preamble more quickly. We will hold two public hearings. If asbestos exposure at metal and you wish to make a statement for the nonmetal mines, surface coal mines, I. Introduction record, please submit your request to us A. Outline of Preamble and surface areas of underground coal B. Dates and Locations for Public Hearings at least 5 days prior to the hearing dates mines. The proposed rule would reduce C. Executive Summary by one of the methods listed in the the full-shift permissible exposure limit D. Abbreviations and Acronyms ADDRESSES section above. The hearings and the excursion limit for airborne II. Background will begin at 9 a.m. with an opening asbestos fibers, and make several A. Scope of Proposed Rule statement from MSHA, followed by nonsubstantive changes to add clarity to B. Where Asbestos Is Found at Mining statements or presentations from the the standard. Exposure to asbestos has Operations public, and end after the last speaker (in C. Asbestos Minerals been associated with lung and other III. History of Asbestos Regulation any event not later than 5 p.m.) on the cancers, mesotheliomas, and asbestosis. A. MSHA’s Asbestos Standards for Mining following dates at the locations This proposed rule would help assure B. OSHA’s Asbestos Standards for General indicated: that fewer miners who work in an Industry and Construction October 18, 2005, Denver Federal environment where asbestos is present C. Other Federal Agencies Regulating Center, Sixth and Kipling, Second would suffer material impairment of Asbestos Street, Building 25, Denver, Colorado health or functional capacity over their D. Other Asbestos-Related Activities 80225, Phone: 303–231–5412. E. U.S. Department of Labor, Office of the working lifetime. Inspector General (OIG) October 20, 2005, Mine Safety and DATES: We must receive your comments IV. Health Effects of Asbestos Exposure Health Administration, 1100 Wilson on or before September 20, 2005. We A. Summary of Asbestos Health Hazards Boulevard, Room 2539, Arlington, will hold public hearings on October 18 B. Factors Affecting the Occurrence and Virginia 22209, Phone: 202–693– and 20. Details about the public Severity of Disease 9457. hearings are in the SUPPLEMENTARY C. Specific Human Health Effects We will hear scheduled speakers first, D. Support from Toxicological Studies of INFORMATION section of this preamble. in the order that they sign in; however, Human Health Effects of Asbestos you do not have to make a written ADDRESSES: (1) To submit comments, Exposure please include ‘‘RIN: 1219–AB24’’ in the V. Characterization and Assessment of request to speak. To the extent time is subject line of the message and send Exposures in Mining available, we will hear from persons them to us at either of the following A. Determining Asbestos Exposures in making same-day requests. The addresses. Mining presiding official may exercise • Federal e-Rulemaking portal: Go to B. Exposures from Naturally Occurring discretion to ensure the orderly progress http://www.regulations.gov and follow Asbestos of the hearing by limiting the time C. Exposures from Introduced the online instructions for submitting allocated to each speaker for their (Commercial) Asbestos presentation. comments. D. Sampling Data and Exposure • E-mail: [email protected]. Calculations The hearings will be conducted in an If you are unable to submit comments VI. The Application of OSHA’s Risk informal manner. Although formal rules electronically, please identify them by Assessment to Mining of evidence or cross examination will ‘‘RIN: 1219–AB24’’ and send them to us A. Summary of Studies Used by OSHA in not apply, the hearing panel may ask by any of the following methods. Its Risk Assessment questions of speakers and a verbatim • Fax: 202–693–9441. B. Models Selected by OSHA (1986) for transcript of the proceedings will be • Mail, hand delivery, or courier: Specified Endpoints and for the prepared and made a part of the Determination of Its PEL and STEL rulemaking record. We also will post the MSHA, Office of Standards, C. OSHA’s Selection of Its PEL (0.1 f/cc) Regulations, and Variances, 1100 D. Applicability of OSHA’s Risk transcript on MSHA’s Home Page at Wilson Blvd., Rm. 2350, Arlington, VA Assessment to the Mining Industry http://www.msha.gov, on the Asbestos 22209–3939. E. Significance of Risk Single Source Page. (2) We will post all comments on the VII. Section-by-Section Discussion of Speakers and other attendees may Internet without change, including any Proposed Rule present information to the MSHA panel personal information they may contain. A. Sections 56/57.5001(b)(1) and 71.702(a): for inclusion in the rulemaking record. You may access the rulemaking docket Definitions We will accept written comments and via the Internet at http://www.msha.gov/ B. Sections 56/57.5001(b)(2) and 71.702(b): data for the record from any interested Permissible Exposure Limits (PELs) party, including those not presenting regsinfo.htm or in person at MSHA’s C. Sections 56/57.5001(b)(3) and 71.702(c): public reading room at 1100 Wilson Measurement of Airborne Fiber oral statements. The post-hearing Blvd., Rm. 2349, Arlington, VA. Concentration comment period will close on (3) To receive an e-mail notification D. Discussion of Asbestos Take-Home November 21, 2005, 30 days after the when we publish rulemaking Contamination last public hearing.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00002 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43951

C. Executive Summary A specifies basic elements of a PCM II. Background method for analyzing airborne asbestos In March of 2001, the U.S. A. Scope of Proposed Rule Department of Labor, Office of the samples. It includes the same analytical This proposed rule would apply to Inspector General (OIG) published a elements specified in our existing metal and nonmetal mines, surface coal report evaluating MSHA’s enforcement standards and allows MSHA’s use of mines, and the surface areas of actions at the vermiculite mine in Libby, other methods that meet the statistical underground coal mines. Because Montana. The widespread asbestos equivalency criteria in OSHA’s asbestos asbestos from any source poses a health contamination at this mine and standard. hazard to miners if they inhale it, the surrounding community, together with The scope of this proposed rule, proposed rule would cover all miners the prevalence of asbestos-related therefore, is limited to lowering the exposed to asbestos whether naturally illnesses and fatalities among persons permissible exposure limits, an issue occurring or contained in building living in this community, attracted press raised by the OIG; incorporating materials, in other manufactured and public attention, which prompted Appendix A of OSHA’s asbestos products at the mine, or in mine waste the OIG investigation and report. The standard for the analysis of our asbestos samples; and making several or tailings. OIG found that MSHA had conducted The National Institute for regular inspections and personal nonsubstantive conforming amendments to our existing rule Occupational Safety and Health exposure sampling at the mine, as (NIOSH) and other research required by the Federal Mine Safety and language. After considering several regulatory approaches to prevent take- organizations and scientists (see Table Health Act of 1977 (Mine Act). The OIG VI–5) have observed the occurrence of report stated, ‘‘We do not believe that home contamination, we determined that non-regulatory measures could cancers and asbestosis among metal and more inspections or sampling would nonmetal miners involved in the mining have prevented the current situation in adequately address this potential hazard. and milling of commodities that contain Libby.’’ The OIG made five asbestos. For this reason, our primary recommendations to MSHA; two of D. Abbreviations and Acronyms focus at metal and nonmetal mines is on which we implemented immediately. As a quick reference, we list below asbestos in pockets or veins of mined The remaining recommendations are some of the abbreviations used in the commodities. Historically, there has listed below: preamble. been no evidence of coal miners • Lower the existing permissible 29 CFR Title 29, Code of Federal encountering naturally occurring exposure limit (PEL) for asbestos to a asbestos.1 The more likely exposure to more protective level. Regulations 30 CFR Title 30, Code of Federal asbestos in coal mining would occur • Use transmission electron Regulations from introduced asbestos-containing microscopy (TEM) instead of phase AFL–CIO American Federation of Labor products, such as asbestos-containing contrast microscopy (PCM) in the initial and Congress of Industrial Organizations building materials (ACBM) in surface analysis of fiber samples that may ATSDR Agency for Toxic Substances and structures. contain asbestos. Disease Registry, Centers for Disease In 2000, the OIG investigated MSHA’s • Control and Prevention, U.S. Department Implement special safety activities at the vermiculite mine in requirements to address take-home of Health and Human Services Bureau former Bureau of Mines, U.S. Libby, Montana. The OIG’s conclusions contamination. and recommendations, discussed later, In response to the OIG’s Department of the Interior cc cubic centimeter (cm3) = milliliter (mL) are consistent with MSHA’s recommendations, MSHA published an EPA U.S. Environmental Protection Agency observations and concerns that— advance notice of proposed rulemaking f fiber(s) • Miners are exposed to asbestos at (ANPRM) on March 29, 2002 (67 FR FR Federal Register mining operations where the ore body 15134). MSHA also held seven public Lpm liter(s) per minute or surrounding rock contains asbestos; meetings around the country to seek MESA former Mining Enforcement and • Miners are potentially exposed to input and obtain public comment on Safety Administration, U.S. Department of the Interior (predecessor to MSHA) airborne asbestos at mine facilities with how best to protect miners from installed asbestos-containing material exposure to asbestos. MSHA Mine Safety and Health Administration, U.S. Department of Labor when it is disturbed during Following review of all public mm millimeter = 1 thousandth of a meter maintenance, construction, renovation, comments and testimony taken at the (0.001 m) or demolition activities; and public meetings, and relying on OSHA’s mL milliliter = 1 thousandth of a liter • Family and community are 1986 asbestos risk assessment, we (0.001 L) = cubic centimeter potentially exposed if miners take determined that it is appropriate to NIOSH National Institute for Occupational asbestos home on their person, clothes, propose reducing the PELs for asbestos Safety and Health, Centers for Disease or equipment, or in their vehicle. Control and Prevention, U.S. Department and clarify criteria for asbestos sample We developed this proposed rule analysis. To enhance the health and of Health and Human Services OIG Office of the Inspector General, U.S. based on our experience with asbestos, safety of miners, we are proposing to Department of Labor our assessment of the health risks, the lower the existing 8-hour, time- OSHA Occupational Safety and Health OIG’s recommendations, and public weighted average (TWA) PEL of 2.0 f/cc Administration, U.S. Department of Labor comments on MSHA’s ANPRM to 0.1 f/cc, and to lower the short-term PCM phase contrast microscopy addressing the OIG’s recommendations. limit from 10.0 f/cc over a minimum PEL permissible exposure limit We received numerous comments in sampling time of 15 minutes to an PLM polarized light microscopy response to the ANPRM and at the excursion limit PEL of 1.0 f/cc over a STEL short-term exposure limit SWA shift-weighted average concentration minimum sampling time of 30 minutes. 1 TEM transmission electron microscopy Personal communication with Professor Kot Unrug, Department of Mining Engineering, To clarify the criteria for the analytical TWA time-weighted average concentration method in our existing standards, we µ University of Kentucky, on November 14, 2003; and m micron = micrometer = 1 millionth of a with Syd S. Peng, Chairman, Department of Mining are proposing to incorporate a reference meter (0.000001 m) Engineering, College of Engineering and Mineral to Appendix A of OSHA’s asbestos USGS U.S. Geological Survey, U.S. Resources, West Virginia University, the week of standard (29 CFR 1910.1001). Appendix Department of the Interior October 24, 2003.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00003 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 43952 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

public meetings, some of which asbestos have been found in other ores 1. Mineralogical Classification and suggested or supported additional in specific geographic regions, primarily Mineral Names 2 requirements beyond those addressed in metamorphic or igneous rock. The terminology used to refer to how by the OIG. We believe that the Although less common, it is not minerals form and how they are named comments to the ANPRM do not justify impossible to find asbestos in is complex. A mineral’s physical an expansion of the scope, at this time, sedimentary rock, soil, and air from the properties, composition, crystalline beyond the recommendations weathering or abrasion of other structure, and morphology determine its specifically raised in the OIG report. asbestos-bearing rock.3 The areas where classification. Asbestos minerals belong On the contrary, we believe that our asbestos may be located can be to either the serpentine (sheet silicate) data support a narrowed scope in that determined from an understanding of or the amphibole (double-chain silicate) we specifically are not proposing two of the mineralogy of asbestos and the family of minerals. Most of the the OIG’s recommendations, i.e., routine geology required for its formation. In difficulties in classifying minerals as use of TEM for the initial analysis of some cases, visual inspection can detect asbestos have involved the amphiboles. exposure samples and promulgation of the presence of asbestos. MSHA The formation of a particular mineral standards to prevent take-home experience indicates that miners may (chemical composition) or habit contamination. We are proposing, encounter asbestos during the mining of (morphology, crystalline structure) however, to lower our permissible 4 a number of mineral commodities, occurs gradually and may be exposure limits. such as talc, limestone and dolomite, incomplete, producing intermediate We have decided not to propose to vermiculite, wollastonite, banded change our existing definition of minerals that are difficult to classify. In ironstone and taconite, lizardite, and the past, there have been several asbestos in this rulemaking. There are antigorite. Not all mines of a specific several reasons for this. different systems used to classify and commodity contain asbestos in the ore, name minerals that, in some instances, First, this rulemaking is limited in however, and the mines that do have scope. We believe that a 20-fold led to inconsistent terminology and asbestos in the ore may encounter it classification. Currently, there is no lowering of the exposure limits, as we rarely. have proposed, together with our single, universally accepted system for Asbestos also is contained in building enhanced measures to educate the naming minerals. materials and other manufactured mining community about the asbestos Asbestos is a commercial term used to products found at mines. Contrary to the hazard in mining, would increase describe certain naturally occurring, common public perception, asbestos is protection for miners and help avoid the hydrated silicate minerals. Several not banned in the United States.5 The future development of situations such as Federal agencies have regulations that U.S. Geological Survey (USGS) that in Libby, Montana. focus on these minerals. The properties Second, interest in the definition of estimates that about 13,000 metric tons of asbestos that give it commercial value asbestos extends to numerous agencies (29 million pounds) of asbestos were include low electrical and thermal used in product manufacturing in the conductivity, chemical and crystalline in Federal, state, and local governments. 6 Our existing definition is consistent United States during 2001. In addition stability and durability, high tensile with several Federal agencies’ to domestic manufacturing, the United strength, flexibility, and friability. Much regulatory provisions, including States continues to import products that of the existing health risk data for OSHA’s. Changing the definition would contain asbestos. Asbestos may be used asbestos uses commercial mineral require considerable interagency for a number of purposes at a mine terminology. Meeker et al. (2003) consultation and coordination; including insulation; reinforcement of recognized the confusion associated additional scientific evaluation; and an cements; reinforcement of floor, wall, with asbestos nomenclature, stating— and building tile; and automotive clutch unnecessary delay in providing miners 7 Within much of the existing asbestos access to the benefits of this proposed and brake linings. If asbestos is present literature, mineral names are not applied in rule. at the mine, miners in the vicinity are a uniform manner and are not all consistent Third, we believe another Libby-like potentially at increased risk from with presently accepted mineralogical mining operation would not exist today asbestos exposure, regardless of whether nomenclature and definitions. because such a business arguably would or not they are actually working with a. Variations in Mineral Morphology. not be economically viable. If a mine’s asbestos. There are many types of crystal ore contained significant amounts of C. Asbestos Minerals habits, such as fibrous, acicular (slender asbestos-like minerals, there is a strong and needle-like), massive (irregular likelihood of potential liability risks, To understand the scientific form), and columnar (stout and column- both from customers and workers, and literature, information about asbestos, like). The morphology of a mineral may the possibility that the mine’s product and the issues raised in the public not fit a precise definition. For example, would be commercially unmarketable. comments, it is important to understand Meeker et al. (2003) state that the Libby Such market forces are likely to compel the terminology used to describe amphiboles contain ‘‘a complete range mining companies of all sizes to sample minerals, asbestos, and fibers. This of morphologies from prismatic crystals the ore for the presence of hazardous section briefly reviews a number of key to asbestiform fibers.’’ Some minerals fibrous minerals before purchasing or terms and concepts associated with crystallize in more than one habit. Some developing a mine site. In our view, asbestos that we use in discussing this minerals, which can form in different these commercial reasons make it proposed rule. habits, have a different name for each unlikely that a new Libby-like mining habit; others do not.8 For example, condition would arise in the future. 2 MSHA (Bank), 1980. crocidolite is the name for the 3 USGS, 1995. asbestiform habit and riebeckite is the B. Where Asbestos Is Found at Mining 4 Roggli et al., 2002; Selden et al., 2001; Amandus name for the same mineral in its Operations et al., Part I, 1987; Amandus et al., Part III, 1987; Amandus and Wheeler, Part II, 1987. nonasbestiform habit. Tremolite and Asbestos is no longer mined as a 5 GETF Report, pp. 12–13, 2003. actinolite do not have different names commodity in the United States. Even 6 USGS (Virta), p. 28, 2003. so, veins, pockets, or intrusions of 7 Lemen, 2003; Paustenbach et al., 2003. 8 Reger and Morgan, 1990; ATSDR, p. 138, 2001.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00004 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43953

depending on habit; therefore, to differentiated from asbestos. In the asbestiform fibers and cleavage distinguish between the different habits, context of systems for naming and fragments in certain size ranges is the descriptive term ‘‘asbestiform’’ or classifying fibrous amphiboles, Meeker difficult or impossible when only a ‘‘asbestos’’ is added to the mineral’s et al. (2003) state that the regulatory small number of structures are available name. If the identifying, descriptive literature often gives nominal for review, as opposed to a term is not used with the mineral name, compositions for a mineral without representative population. Meeker et al. misunderstandings or mistakes may specifying chemical boundaries. (2003) states that it is often difficult or occur. impossible to determine differences 2. Differentiating Asbestiform and b. Variations in Mineral Composition. between acicular cleavage fragments Nonasbestiform Habit Atoms similar in size and valence and asbestiform mineral fibers on an state can replace each other within a In the asbestiform habit, mineral individual fiber basis. A determination mineral’s crystal lattice, resulting in the crystals grow forming long, thread-like as to whether a mineral is asbestiform formation of a different mineral in the fibers. When pressure is applied to an or not must be made, where possible, by same mineral series. This process is asbestos fiber, it bends much like a wire, applying existing analytical methods. gradual and can occur to a different rather than breaks. Fibers can separate Although we have received comments extent in the same mineral depending into ‘‘fibrils’’ of a smaller diameter regarding the hazards associated with on the geological conditions during its (often less than 0.5 µm). This effect is cleavage fragments, we do not intend to formation. For example, tremolite referred to as ‘‘polyfilamentous,’’ and modify our existing definition of contains magnesium, but no (or little) should be viewed as one of the most asbestos with this rulemaking. iron, and holds an end member position important characteristics of asbestos. in its mineral series. Iron atoms can Appendix A of the Environmental III. History of Asbestos Regulation replace the magnesium atoms in Protection Agency’s (EPA’s) Method for When Federal agencies responsible tremolite and the resulting mineral may the Determination of Asbestos in Bulk for occupational safety and health began then be called actinolite. The quantity of Building Materials 10 defines to regulate occupational exposure to iron needed before the mineral is called asbestiform as follows: asbestos, studies had already actinolite varies depending on the * * * a mineral that is like asbestos, i.e., established that the inhalation of mineral classification scheme used. crystallized with the habit [morphology] of asbestos fibers was a major cause of Another example is winchite, which is asbestos. Some asbestiform minerals may disability and death among exposed an intermediate member of the lack the properties which make asbestos workers. The intent of these first tremolite-glaucophane series, as well as commercially valuable, such as long fiber asbestos rules was to protect workers length and high tensile strength. With the an end member in its own sodic-calcic 11 light microscope, the asbestiform habit is from developing asbestosis. series.9 Given the chemical similarity generally recognized by the following A. MSHA’s Asbestos Standards for within the series, winchite characteristics: 3∂ Mining [(NaCa)Mg4(Al,Fe )Si8O 22(OH)2] often Mean aspect [length to width] ratios has been reported as tremolite ranging from 20:1 to 100:1 or higher for fibers 1967–1969. In 1967, under the former [Ca2Mg5Si8O22(OH)2]. longer than 5 micrometers. Aspect ratios Bureau of Mines, predecessor to the A specific rock formation may contain should be determined for fibers, not bundles. Mining Enforcement and Safety a continuum of minerals from one end Very thin fibrils, usually less than 0.5 Administration (MESA) and then micrometers in width, and two or more of the member of a series to the other end following: MSHA, the standard for asbestos member, creating a solid solution of exposure in mining was an 8-hour, time- —Parallel fibers occurring in bundles, intermediate minerals. These —Fiber bundles displaying splayed ends, weighted average (TWA) PEL of 5 mppcf intermediate minerals are sometimes —Matted masses of individual fibers, and/or (million particles per cubic foot of air). given names, while at other times they —Fibers showing curvature. In 1969, the Bureau promulgated a 2 are not. Often, when the exact chemical In the nonasbestiform habit, mineral mppcf and 12 f/mL (fibers per milliliter) composition is not determined or crystals do not grow in long thin fibers. standard. determined to be a number of different They grow in a more massive habit. For 1974–1976. In 1974, MESA intermediate minerals, the mineral is example, a long thin crystal may not be promulgated a 5 f/mL standard for named by one or more of its end polyfilamentous nor possess high asbestos exposure in metal and members, such as tremolite-actinolite or tensile strength and flexibility, but may nonmetal mines (39 FR 24316). In 1976, cummingtonite-grunerite. The fibrous break rather than bend. When pressure MESA promulgated a 2 f/cc standard (41 amphiboles in the Libby ore body, for is applied, the nonasbestiform crystals FR 10223) for asbestos exposure in example, contain both end members and fracture easily into prismatic particles, surface areas of coal mines. We retained several intermediate minerals. Meeker et which are called cleavage fragments these standards under the authority of al. (2003) state that— because they result from the particle’s the Federal Mine Safety and Health Act The variability of compositions on the breaking or cleavage, rather than the of 1977. micrometer scale can produce single fibrous crystal’s formation or growth. Some 1978. In November 1978, we particles that can have different amphibole particles are acicular (needle shaped), promulgated a 2 f/mL standard for names at different points of the particle. and stair-step cleavage along the edges asbestos exposure in metal and A mineral may also undergo of some particles is common. nonmetal mines (43 FR 54064). Since transition to a different mineral series. Cleavage fragments may be formed then, we have made only Kelse and Thompson (1989), Ross when nonfibrous amphibole minerals nonsubstantive changes to our asbestos (1978), and USGS (Virta, 2002) have are crushed, as may occur in mining and standards, e.g., renumbering the section commented on the chemical transition milling operations. Cleavage fragments of the standard in 30 CFR. of anthophyllite to talc. Stewart and Lee are not asbestiform and do not fall MSHA’s existing standards for (1992) stated that fibrous talc might within our definition of asbestos. For asbestos at metal and nonmetal mines at contain intermediate particles not easily some minerals, distinguishing between 30 CFR 56/57.5001 state,

9 Leake et al., p. 222, 1997. 10 EPA, 1993. 11 GETF Report, p. 33, 2003.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00005 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 43954 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

(b) The 8-hour time-weighted average cc and a peak exposure level (ceiling provisions of the 1986 revised airborne concentration of asbestos dust to limit) of 10 f/cc. In June 1972, OSHA standards. In Building Construction which employees are exposed shall not promulgated these limits in a final rule. Trades Division (BCTD), AFL-CIO v. exceed 2 fibers per milliliter greater than 5 1975. In October 1975, OSHA Brock (838 F.2d 1258, 1988), the U.S. microns in length, as determined by the proposed to revise its asbestos standard membrane filter method at 400–450 Court of Appeals for the District of magnification (4 millimeter objective) phase by reducing the 8-hour, TWA PEL to 0.5 Columbia upheld most of the challenged contrast illumination. No employees shall be f/cc with a ceiling limit of 5 f/cc for 15 provisions, but remanded certain issues exposed at any time to airborne minutes (40 FR 47652). OSHA stated to OSHA for reconsideration. In partial concentrations of asbestos fibers in excess of that sufficient medical and scientific response, on September 14, 1988, OSHA 10 fibers longer than 5 micrometers, per evidence had accumulated to warrant promulgated an excursion limit of 1 f/ milliliter of air, as determined by the the designation of asbestos as a human cc for asbestos as measured over a 30- membrane filter method over a minimum carcinogen and that advances in minute sampling period (53 FR 35610). sampling time of 15 minutes. ‘‘Asbestos’’ is monitoring and protective technology 1992. OSHA’s 1986 standards had a generic term for a number of hydrated made re-examination of the standard applied to occupational exposure to silicates that, when crushed or processed, separate into flexible fibers made up of appropriate. The final rule, however, nonasbestiform actinolite, tremolite, and fibrils. Although there are many asbestos reduced OSHA’s 8-hour, TWA asbestos anthophylite. On June 8, 1992, OSHA minerals, the term ‘‘asbestos’’ as used herein PEL to 2 f/cc due to feasibility concerns. deleted the nonasbestiform types of is limited to the following minerals: This limit remained in effect until these minerals from the scope of its chrysotile, Amosite, crocidolite, anthophylite OSHA revised it in 1986. asbestos standards. In evaluating the asbestos, tremolite asbestos, and actinolite 1983–1986. On November 4, 1983, record, OSHA found (57 FR 24310– asbestos. OSHA published another emergency 24311) insufficient evidence that The existing standard for asbestos at temporary standard (ETS) for asbestos nonasbestiform actinolite, tremolite, and surface coal mines and surface work (48 FR 51086), which would have anthophyllite present ‘‘a risk similar in areas of underground coal mines at 30 lowered the 8-hour, TWA PEL from 2 f/ kind and extent’’ to their asbestiform CFR 71.702 states, cc to 0.5 f/cc. The Asbestos Information counterparts. Additionally, the evidence Association challenged the ETS in the (a) The 8-hour average airborne did not show that OSHA’s removal of concentration of asbestos dust to which U.S. Court of Appeals for the 5th the nonasbestiform types of these three miners are exposed shall not exceed two Circuit. On March 7, 1984, ruling on minerals from its asbestos standard fibers per cubic centimeter of air. Exposure Asbestos Information Association/North ‘‘will pose a significant risk to exposed to a concentration greater than two fibers per America v. OSHA (727 F.2d 415, 1984), employees.’’ cubic centimeter of air, but not to exceed 10 the Court invalidated the ETS. 1994. On August 10, 1994, OSHA fibers per cubic centimeter of air, may be Subsequent to this decision, OSHA published a final rule (59 FR 40964) that permitted for a total of 1 hour each 8-hour published a proposed rule (49 FR lowered its 8-hour, TWA PEL for day. As used in this subpart, the term 14116) that, together with the ETS, asbestos to 0.1 f/cc and retained the 1 asbestos means chrysotile, amosite, proposed two alternatives for lowering f/cc excursion limit as measured over 30 crocidolite, anthophylite asbestos, tremolite the 8-hour, TWA PEL: 0.2 f/cc and 0.5 minutes. asbestos, and actinolite asbestos but does not include nonfibrous or nonasbestiform f/cc. On June 17, 1986, OSHA issued C. Other Federal Agencies Regulating minerals. Asbestos (b) The determination of fiber comprehensive asbestos standards (51 concentration shall be made by counting all FR 22612) governing occupational Because the health hazards of fibers longer than 5 micrometers in length exposure to asbestos in general industry exposure to asbestos are well and with a length-to-width ratio of at least 3 workplaces (29 CFR 1910.1001), recognized, it is highly regulated. OSHA to 1 in at least 20 randomly selected fields construction workplaces (29 CFR and MSHA have the primary authority using phase contrast microscopy at 400–450 1926.1101), and shipyards (29 CFR to regulate occupational exposures to magnification. 1915.1001). The separate standards asbestos. EPA regulates asbestos 1989. In 1989, as part of our Air shared the same asbestos PEL and most exposure of state and local government Quality rulemaking, we proposed to ancillary requirements. These standards workers in those states that do not have lower the full-shift exposure limit for reduced OSHA’s 8-hour, TWA PEL to an OSHA State Plan covering them. A asbestos from 2 f/cc to 0.2 f/cc to 0.2 f/cc from the previous 2 f/cc limit. number of other Federal agencies, address the excessive risk quantified in OSHA added specific provisions in the primarily EPA and the Consumer the Occupational Safety and Health construction standard to cover unique Product Safety Commission (CPSC), Administration’s (OSHA’s) 1986 hazards relating to asbestos abatement regulate non-occupational asbestos asbestos rule (54 FR 35760). The Air and demolition jobs. exposures. For example, CPSC regulates Quality rulemaking, however, was Although tremolite, actinolite, and asbestos in consumer products, such as withdrawn on September 26, 2002 (67 anthophyllite exist in different forms, patching compounds, under the Federal FR 60611). MSHA has not reinstated the OSHA determined that all forms of Hazardous Substances Act. Air Quality rulemaking at this time. these minerals would continue to be EPA regulates asbestos in air and regulated. Following promulgation of materials. EPA’s activities have focused B. OSHA’s Asbestos Standards for the rule, several parties requested an on environmental issues and the public General Industry and Construction administrative stay of the standard health by reducing emissions of 1971–1972. The initial promulgation claiming that OSHA improperly hazardous gases and dusts from large of OSHA standards on May 29, 1971 (36 included nonasbestiform minerals. A industrial sources, such as taconite ore FR 10466) included a 12 f/cc PEL for temporary stay was granted and OSHA processing,12 and the cleanup of asbestos. Then, on December 7, 1971, in initiated rulemaking to remove the contaminated waste sites. EPA also response to a petition by the Industrial nonasbestiform types of these minerals regulates asbestos in schools. The Union Department of the AFL-CIO, from the scope of the asbestos mining and processing of vermiculite in OSHA issued an emergency temporary standards. Libby, Montana, resulted in the spread standard (ETS) on asbestos that 1988. Several major participants in established an 8-hour, TWA PEL of 5 f/ OSHA’s rulemaking challenged various 12 EPA (68 FR 61868), 2003.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00006 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43955

of asbestos to numerous homes, schools, 2. National Institute for Occupational the updated asbestos toxicological and businesses throughout the town. In Safety and Health (NIOSH) profile and the meeting proceedings and November 1999, EPA responded to a The Workers’ Family Protection Act have discussed this information in this request to study the environmental of 1992 (29 U.S.C. 671A) directed preamble, where appropriate. contamination in the town of Libby and NIOSH to study contamination of E. U.S. Department of Labor, Office of widespread illnesses and death among workers’ homes by hazardous the Inspector General (OIG) its residents. In October 2002, EPA substances, including asbestos, In November 1999, a Seattle designated the area as a Superfund site. transported from the workplace. newspaper published a series of articles ATSDR, EPA, OSHA, MSHA, the U.S. D. Other Asbestos-Related Activities on the unusually high incidence of Department of Energy (DOE), and the asbestos-related illnesses and fatalities There have been increasing numbers Centers for Disease Control and among individuals who had lived in of studies on asbestos and its hazards Prevention (CDC) assisted NIOSH in Libby, Montana. There was extensive over the past 40 years. These efforts conducting the study. For this proposed national media attention surrounding encompass government, industry, and rule we focused on the asbestos-related the widespread environmental academia on a local, national, and results of these studies. contamination and asbestos-related NIOSH (1995) published its study international scale. Government deaths in Libby. Dust and construction results in a Report to Congress on agencies and scientific groups in the materials from the nearby vermiculite Workers’ Home Contamination Study United States, such as the National mine were the alleged cause. This mine Conducted under the Workers’ Family had produced about 90 percent of the Institute for Occupational Safety and Protection Act. This report summarizes world’s supply of vermiculite from 1924 Health (NIOSH), the Agency for Toxic incidents of home contamination, Substances and Disease Registry until 1992. including the health consequences, Because MSHA had jurisdiction over (ATSDR), the American Conference of sources, and levels of contamination. Governmental Industrial Hygienists the mine for two decades before it The study documents cases of asbestos closed, the OIG investigated MSHA’s (ACGIH), and the National Toxicology reaching workers’ homes in 36 states in Program (NTP), have addressed issues enforcement actions at the mine. The the United States and in 28 other OIG confirmed that the processing of involving carcinogens, such as asbestos. countries. These cases covered a wide vermiculite at the mine exposed miners Organizations from other countries, variety of materials, industries, and to asbestos. The miners then, such as the United Kingdom (Health occupations. The means by which inadvertently, had carried the asbestos and Safety Executive) and Germany hazardous substances reached workers’ home on their clothes and in their (Deutche Forschungsgemeinschaft), also homes and families included taking the personal vehicles.14 In doing this, the have addressed occupational exposure substance home on the worker’s body, miners continued to expose themselves to asbestos and other carcinogens. clothing, tools, and equipment; cottage and family members. Similarly, the International Agency for industries (i.e., work performed on Research on Cancer (IARC) has home property); and family visits to the 1. OIG Report on MSHA’s Handling of published a monograph on asbestos that workplace. In an effort to reach Inspections at the W.R. Grace & summarizes evidence of its employers and workers, NIOSH (1997) Company Mine in Libby, Montana carcinogenicity.13 published its recommendations in The OIG published its findings and Protect Your Family: Reduce recommendations in a report dated 1. Interagency Asbestos Work Group Contamination at Home. This pamphlet March 22, 2001. The OIG found that (IAWG) summarizes the NIOSH study and MSHA had appropriately conducted provides recommendations to prevent OSHA’s and EPA’s overlapping regular inspections and personal this contamination. exposure sampling at the Libby mine responsibilities and common interest in and that there were no samples addressing asbestos hazards led to the 3. Agency for Toxic Substances and Disease Registry (ATSDR) exceeding the 2.0 f/cc PEL for the 10 formation of the IAWG. Participating years prior to the mine closing in 1992. Federal agencies include EPA, OSHA, The Superfund Amendments and The OIG concluded, ‘‘We do not believe CPSC, MSHA, NIOSH, ATSDR, USGS, Reauthorization Act of 1986 (SARA) that more inspections or sampling and the National Institute of Standards directed ATSDR to prepare toxicological would have prevented the current and Technology (NIST). This work profiles for hazardous substances most situation in Libby.’’ The OIG stated its group of government agencies facilitates commonly found at specific waste sites. belief that there is a need for MSHA to the sharing of information and ATSDR and EPA determined which lower its asbestos PEL. coordination of activities, including hazardous substances pose the most In its report, the OIG supported the regulatory activities, environmental significant potential threat to human development and implementation of assessment, technical assistance, health and targeted them for study. control measures for asbestos and consumer protection, and developments Asbestos is one of these targeted vermiculite mining and milling. They in environmental analysis of substances. ATSDR published one of the also made recommendations for contaminants. The IAWG also seeks to most current toxicological profiles for improving our effectiveness in harmonize the policies, procedures, and asbestos in September 2001, which was controlling this hazard. This proposed enforcement activities of the an update of an earlier asbestos profile. rule addresses our responses to several In October 2002, ATSDR sponsored a participating agencies, thus minimizing of the OIG’s recommendations. meeting of expert panelists who or eliminating potential conflicts for the presented their evaluation of state-of- 2. MSHA’s Libby, Montana Experience regulated community. For example, the the-art research concerning the W.R. Grace acquired the vermiculite IAWG is currently discussing the relationship between fiber length and mine in Libby, Montana, in 1963. At Federal definition of asbestos. the toxicity of asbestos and synthetic that time, the amphibole in the vitreous fibers. We have reviewed the 13 IARC, 1987. evidence and arguments presented in 14 Weis et al., 2001.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00007 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 43956 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

vermiculite was called tremolite, soda 1970’s. McDonald et al. (1986) may contain asbestos. It included tremolite, soda-rich tremolite, or reported— recommendations to help mine richterite, and researchers had already In 1974, the old dry and wet mills were operators reduce miners’ exposures, to linked the mine dust to respiratory closed and the ore was processed in a new prevent or minimize take-home disease.15 The suggested exposure limit mill built nearby which operated on an contamination, and for the selection and for asbestos in mining was much higher entirely wet basis in which separation was use of respiratory protection. The PIB than current limits. The federal standard made by vibrating screens, Humphrey also urged mine operators to minimize for asbestos in mining dropped from 5 separators, and flotation. exposures, to improve controls, and to mppcf (about 30 f/mL) in 1967 to 2 f/ McDonald et al. (1986) and Amandus train miners, listing specific training mL in 1978. When MESA (predecessor and Wheeler (Part II, 1987) also showed topics as essential for miners potentially agency to MSHA) began inspecting the that, even at reduced exposure levels, exposed to asbestos. operation, the exposure limit for there was still increased risk of lung During this same period, 2000 to asbestos was 5 f/mL. cancer among the Libby miners and 2003, we conducted an asbestos The mine operator, Federal mine millers. awareness campaign and increased asbestos sampling. Section VII.D of this inspectors, and representatives of the 3. MSHA’s Efforts To Minimize preamble contains an additional U.S. Public Health Service [part of the Asbestos Take-Home Contamination Centers for Disease Control and discussion of measures to prevent Prevention (CDC)] routinely sampled for ‘‘Take-home’’ contamination is asbestos ‘‘take-home’’ contamination. asbestos at the Libby mine, starting contamination of workers’ homes or We have decided not to pursue a before the mine switched to wet vehicles by hazardous substances regulatory approach to minimizing processing in 1974, and continued transported from the workplace. As asbestos ‘‘take-home’’ contamination. sampling periodically until the mine discussed previously in this preamble, Based on the existing levels of asbestos the widespread asbestos-related disease closed in 1992. MSHA sampling at the exposures in the mining industry, among the residents of Libby, Montana, Libby mine found no exposures comments on our 2002 ANPRM, and was attributed, in part, to take-home exceeding the 5.0 f/cc asbestos PEL from testimony at the subsequent public contamination from the vermiculite 1975 through 1978, and only a few over meetings, we have determined that a mining and milling operation in that the 2.0 f/cc asbestos PEL from 1979 non-regulatory approach would be town. The OIG report on MSHA’s through 1986. Almost all the samples effective in minimizing asbestos take- activities recommended that we would have exceeded the 0.1 f/cc home contamination from mining promulgate special safety standards proposed limit. Miners’ exposures operations. similar to those in our 1989 proposed continued to decrease and more recent Air Quality rule (54 FR 35760) to 4. Training Inspectors to Recognize and sampling since 1986 found few address take-home contamination. Sample for Asbestos exposures exceeding the OSHA PEL of In our 1989 Air Quality proposed The OIG recommended that we 0.1 f/cc. rule, we had proposed that miners wear increase MSHA inspectors’ skills for The results from our personal protective clothing and other personal providing asbestos compliance exposure sampling at the Libby mine protective equipment before entering assistance to mine operators. In included many of the fibrous areas containing asbestos. Our Air response, we developed a half-day amphiboles present. In addition, the Quality proposed rule also would have multimedia training program that results from TEM analysis of the air required miners to remove their includes the following: samples characterized the mineralogy of protective clothing and store them in • A PowerPoint-based training the airborne fibers as tremolite and did adequate containers to be disposed of or presentation that examines MSHA’s not distinguish between the species of decontaminated by the mine operator. procedures for air and bulk asbestos amphiboles. Further characterization of These proposed requirements were sampling. the amphibole minerals using Scanning similar to those in OSHA’s asbestos • An updated ‘‘Chapter 8—Asbestos Electron Microscopy/Energy Dispersive standard and to NIOSH’s Fibers’’ from the Metal and Nonmetal X-ray Spectroscopy technology shows recommendations. Health Inspection and Procedures proportions of about 84 percent In March 2000, shortly after the series Handbook that serves as a text for the winchite, 11 percent richterite, and 6 of articles on asbestos-related illnesses training sessions. percent tremolite.16 and deaths in Libby, Montana, we • A ‘‘hands-on’’ segment that allows As early as 1980, MSHA had issued a Program Information Bulletin the inspectors to examine asbestos and requested that NIOSH investigate health (PIB No. P00–3) about asbestos. The PIB asbestiform rock samples and the problems at all vermiculite operations, served to remind the mining industry of equipment used for bulk sampling, and including the mine and mill in Libby, the potential health hazards from that provides the inspectors instruction Montana. NIOSH published its study exposure to airborne asbestos fibers and and practice in assembling and results in a series of three papers to raise awareness about potential calibrating asbestos fiber air sampling (Amandus et al., Part I, 1987; Amandus asbestos exposure for miners, their apparatus. and Wheeler, Part II, 1987; Amandus et families, and their communities. At that We gave this asbestos training to al., Part III, 1987). The study of time, we also issued a Health Hazard journeymen inspectors from March 2002 Amandus et al. (Part I, 1987) along with Information Card (No. 21) about through April 2003, and added it to the that of McDonald et al. (1986) found asbestos for distribution to miners to training program for entry-level that, historically, the highest exposures raise their awareness about the health inspectors. to fibers at the Libby operation had hazards related to asbestos exposure. IV. Health Effects of Asbestos Exposure occurred in the mill and that exposures The PIB included information about had decreased between the 1960’s and asbestos, its carcinogenic and other The health hazards from exposure to significant health effects, how miners asbestos were discussed extensively in 15 McDonald et al., 1986; Meeker et al., 2003; could be exposed, where asbestos the preamble to OSHA’s 1983 final rule Peipins et al., 2003. occurs naturally on mining property, (51 FR 22615). Subsequently, 16 Meeker et al., 2003 and what types of commercial products researchers have confirmed and

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00008 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43957

increased our knowledge of these fiber-years per cubic centimeter (e.g., 50 stakeholders to recommend a hazards. Exposures in occupational and years at 2 f/cc, 25 years at 4 f/cc, 10 worldwide ban of asbestos.20 environmental settings are generally due years at 10 f/cc) would have a 1 percent B. Factors Affecting the Occurrence and to inhalation, although some asbestos risk of developing early signs of Severity of Disease may be absorbed through ingestion. asbestosis. The correlation of exposure While the part of the body most likely levels with the disease experience of The toxicity of asbestos, and the affected (target organ) is the lung, populations of exposed workers subsequent occurrence of disease, is adverse health effects may extend to the provided a basis for setting an related to its concentration (C) in the linings of the chest, abdominal, and occupational exposure limit for asbestos mine air and to the duration (T) of the pelvic cavities, and the gastrointestinal measured by the concentration of the miner’s exposure. Other variables, such tract. The damage following chronic fibers in air. as the fiber’s characteristics or the exposure to asbestos is cumulative and As mentioned previously, the effectiveness of the miner’s lung irreversible. Workplace exposures to hazardous effects from exposure to clearance mechanisms, also affect asbestos may be chronic, continuing for asbestos are now well known. For this disease severity. many years. The symptoms of asbestos- reason, our discussion in this section 1. Concentration (C) related adverse health effects may not will focus on the results of the more become evident for 20 or more years recent studies and literature reviews, Currently, the concentration (C) of after first exposure (latency period). those published since the publication of asbestos is expressed as the number of OSHA’s risk assessment, and those fibers per cubic centimeter (f/cc). Some A. Summary of Asbestos Health studies have also reported asbestos Hazards involving miners. One such review by Tweedale (2002) stated, concentrations in the number of fibers This section presents an overview of per milliliter (f/mL), which is an human health effects from exposure to Asbestos has become the leading cause of occupational related cancer death, and the equivalent concentration to f/cc. asbestos. We are proposing to use second most fatal manufactured carcinogen MSHA’s existing PELs for asbestos are OSHA’s 1986 risk assessment to (after tobacco). In the public’s mind, asbestos expressed in f/mL for metal and estimate the risk from asbestos has been a hazard since the 1960s and 1970s. nonmetal mines and as f/cc for coal exposures in mining. OSHA’s risk However, the knowledge that the material mines. To improve consistency and assessment has withstood legal scrutiny was a mortal health hazard dates back at least avoid confusion, we express the and the more recent studies discussed a century, and its carcinogenic properties concentration of airborne fibers as f/cc later in this preamble support it. MSHA have been appreciated for more than 50 in this proposed rule, for both coal and has placed OSHA’s risk assessment in years. metal and nonmetal mines. the asbestos rulemaking record. It can Greenberg (2003) also published a Older scientific literature (i.e., 1960’s also be found at http://www.osha.gov. recent review of the biological effects of and 1970’s) reported exposure Studies first identified health asbestos and provided a historical concentrations as million particles per problems associated with occupational perspective similar to that of Tweedale. cubic foot (mppcf) and applied a exposure to asbestos in the early 20th The three most commonly described conversion factor to convert mppcf to century among workers involved in the adverse health effects associated with f/cc. OSHA (51 FR 22617) used a factor manufacturing or use of asbestos- asbestos exposure are lung cancer, of 1.4 when performing these containing products.17 Early studies mesotheliomas, and pulmonary fibrosis conversions. More recently, Hodgson identified the inhalation of asbestos as (i.e., asbestosis). OSHA, in its 1986 and Darnton (2000) recommended the the cause of asbestosis, a slowly asbestos rule, reviewed each of these use of a factor of 3. In our evaluation of progressive disease that produces lung diseases and provided details on the the scientific literature, we did not scarring and loss of lung elasticity. studies demonstrating the relationship critically evaluate the impact of these Studies also found that asbestos caused between asbestos exposure and the and other conversion factors. We note lung and several other types of cancer. clinical evidence of disease. In 2001, the this difference here for completeness. For example, mesotheliomas, rare ATSDR published an updated Because we are relying on OSHA’s risk cancers of the lining of the chest or Toxicological Profile for Asbestos that assessment, we are using OSHA’s abdominal cavities, are almost also included an extensive discussion of conversion factor exclusively attributable to asbestos these three diseases. A search of peer- exposure. Once diagnosed, they are reviewed scientific literature using 2. Time (T) rapidly fatal. Asbestos-related diseases databases, such as Gateway, PubMed, Epidemiological and toxicological have long latency periods, commonly and ToxLine, accessed through the studies generally report time (T) in years not producing symptoms for 20 to 30 National Library of Medicine (NLM), (yr). The product of exposure years following initial exposure. yielded nearly 900 new references on concentration and exposure duration In the late 1960’s, scientists correlated asbestos from January 2000 to October (i.e., C × T) is referred to as ‘‘fiber- phase contrast microscopy fiber 2003. Many of these recent articles 19 years’’.21 When developing exposure- counting methods with the earlier types continue to demonstrate and support response relationships for asbestos- of dust measurements. This procedure findings of asbestos-induced lung induced health effects, researchers provided a means to estimate earlier cancer, mesotheliomas, and asbestosis, typically use ‘‘fiber-years’’ to indicate workers’ asbestos exposures and consistent with the conclusions of the level of workplace exposure. enabled researchers to develop a dose- OSHA and ATSDR. Thus, in the Finkelstein 22 noted, however, that this response relationship with the scientific community, there is product of exposure concentration times occurrence of disease. The British compelling evidence of the adverse duration of exposure (C × T) assumes an Occupational Hygiene Society health effects of asbestos exposure. This equal weighting of each variable (C, T). reported 18 that a worker exposed to 100 has led some researchers and 20 Maltoni, 1999. 17 GETF Report, p. 38, 2003; OSHA (40 FR 47654), 19 Baron, 2001; Bolton et al., 2002; Manning et al., 21 ATSDR, 2001; Fischer et al., 2002; Liddell, 1975. 2002; Nicholson, 2001; Osinubi et al., 2000; Roach 2001; Pohlabeln et al., 2002. 18 Lane et al., 1968; OSHA (40 FR 47654), 1975. et al., 2002. 22 Finkelstein, 1995; ATSDR, p. 42, 2001.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00009 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 43958 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

3. Fiber Characteristics better understand the relationship expectorated. The swallowing of mucus Baron (2001) reviewed techniques for between fiber dimensions, durability, through this clearance mechanism can the measurement of fibers and stated, inhaled dose, and other important result in inhaled asbestos reaching the ‘‘* * * fiber dose, fiber dimension, and factors that determine the health risks of gastrointestinal tract. fiber durability are the three primary exposure not only to asbestos, but also In the air sacs deep within the lungs factors in determining fiber [asbestos] to other fibers. (the alveolar region), pulmonary macrophages engulf foreign matter, toxicity * * *’’. Manning et al. (2002) 4. Differences in Fiber Potency also noted the important roles of bio- including asbestos fibers. The The theory that the differences among persistence (i.e., durability), physical macrophages attempt to remove these properties, and chemical properties in fibers have an effect on their ability to fibers by transporting them to the defining the ‘‘toxicity, pathogenicity, produce adverse effects on human circulatory or lymphatic system. Some and carcinogenicity’’ of asbestos. Roach health has received a great deal of studies have shown that groups of et al. (2002) stated that— attention. Hodgson and Darnton (2000), macrophages try to engulf longer Browne (2001), and Liddell (2001) fibers.28 When asbestos fibers are not Physical properties, such as length, discuss a fiber gradient hypothesis, cleared, they may initiate inflammation diameter, length-to-width (aspect ratio), and which is now termed the amphibole of the cells lining the alveoli. This texture, and chemical properties are believed to be determinants of fiber distribution [in hypothesis. This hypothesis proposes inflammation leads to more serious the body] and disease severity. that the amphiboles (e.g., crocidolite, physical effects in the lungs. OSHA amosite) are more hazardous than the (1986), ATSDR (2001), and several Many other investigators 23 also have serpentine, chrysotile. ATSDR (p. 39, recent papers 29 discuss these concluded that the dimensions of 2001) recently stated that— mechanisms for the pulmonary asbestos fibers are biologically clearance of asbestos. important. Available evidence indicates that all OSHA and MSHA currently specify asbestos fiber types are fibrogenic, although C. Specific Human Health Effects that analysts count those fibers that are there may be some differences in relative potency among fiber types. 1. Lung Cancer over 5.0 micrometers (µm) in length with a length to diameter aspect ratio of In its 1986 asbestos rule, OSHA (51 Lung cancer is a chronic, irreversible, at least 3:1. Several recent FR 22628) stated that— and often fatal disease of the lungs. publications 24 support this aspect ratio, * * * epidemiological and animal Epidemiological studies confirm, and although larger aspect ratios such as 5:1 evidence, taken together, fail to establish a toxicological studies support, the or 20:1 have been proposed.25 There is definitive risk differential for the various carcinogenicity of asbestos. (See section some evidence that longer, thinner types of asbestos fiber. Accordingly, OSHA IV.D. below.) The form of lung cancer asbestos fibers (e.g., greater than 20 µm has * * * recognized that all types of seen most often in asbestos-exposed long and less than 1 µm in diameter) are asbestos fiber have the same fibrogenic and individuals is bronchial carcinoma. carcinogenic potential * * * more potent carcinogens than shorter Some of the risk factors for lung cancer fibers. Suzuki and Yuen (2002), In its comments on MSHA’s asbestos include airborne asbestos concentration, however, concluded that ‘‘Short, thin ANPRM, NIOSH stated that— duration of exposure, fiber dimensions, asbestos fibers should be included in (3) experimental animal carcinogenicity the age of the individual at the time of the list of fiber types contributing to the studies with various minerals have provided first exposure, and the number of years induction of human malignant strong evidence that the carcinogenic since the first exposure.30 Another mesotheliomas * * * ’’. More recently, potential depends on the ‘‘particle’’ length major risk factor is the smoking of Dodson et al. (2003) concluded that all and diameter. The consistency in tobacco products. Numerous studies lengths of asbestos fibers induce tumorigenic responses observed for various have concluded that there are mineral particles of the same size provides pathological responses and that reasonable evidence that neither composition synergistic effects between asbestos and researchers should exercise caution nor origin of the particle is a critical factor tobacco smoke in the development of when excluding a population of inhaled in carcinogenic potential; * * * lung cancer.31 This is especially fibers based on their length. This issue remains unresolved. relevant to miners as NIOSH (May 2003) We have determined that researchers Although possible differences in fiber estimates that 33 percent of miners have found neither a reliable method for potency are beyond the scope of this currently smoke. predicting the contribution of fiber The mechanism through which proposed rule, we will continue to length to the development of disease, asbestos causes lung cancer is under monitor results of research in this area. nor evidence establishing the exact study. Recent papers by Manning et al. relationship between them. There is 5. Lung Clearance Mechanisms (2002), Xu et al. (2002), and Osinubi et suggestive evidence that the dimensions Inhaled asbestos may deposit al. (2000) describe a scheme of cell of asbestos fibers may vary with throughout the respiratory tract, signaling and inflammation with the different diseases. A continuum may depending on the aerodynamic behavior release of reactive oxygen species and exist in which shorter, wider fibers of the fibers.27 As noted by Baron reactive nitrogen species. produce one disease, such as asbestosis, (2001), ‘‘* * * fiber aerodynamic The latency period for asbestos- and longer, thinner fibers produce behavior indicates that small diameter related lung cancer is generally 20–30 26 another, such as mesotheliomas. The fibers are likely to reach into and years, although some cases have been scientific community continues to deposit in the airways of the lungs.’’ reported within 10 years, and some up publish new data that will enable to 50 years, after initial asbestos Clearing the lungs of deposited asbestos 32 regulatory agencies, such as MSHA, to occurs by several mechanisms. In the exposure. Lung cancer caused by mid-airways (i.e., bronchial region), 28 23 ATSDR, 2001; Osinubi et al., 2000; Peacock et small hair-like cells sweep the mucus Warheit, p. 308, 1993. al., 2000; Langer et al., 1979. 29 Baron, 2001; Osinubi et al., 2000. 24 ATSDR, 2001; Osinubi et al., 2000. containing asbestos toward the throat, at 30 Yano et al., 2001; ATSDR, 2001. 25 Wylie et al., 1985. which time it is swallowed or 31 Bolton et al., 2002; Manning et al., 2002; 26 ATSDR, pp. 39–41, 2001; Mossman, pp. 47–50, OSHA, 1986. 2003. 27 ICRP, 1966. 32 Roach et al., 2002.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00010 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43959

asbestos can progress even in the often characterized by a rapid and 3. Asbestosis absence of continued exposure. Thus, in shallow breathing pattern. Asbestosis is a chronic and all of its stages, lung cancer constitutes Mesotheliomas are rapidly progressive irreversible disease caused by the a material impairment of human health even in the absence of continued deposition and accumulation of asbestos or functional capacity. asbestos exposure. Mesotheliomas have in the lungs. It can lead to substantial In the preamble to its 1986 asbestos a poor prognosis in most patients; death injury and may cause death from the standard (51 FR 22615), OSHA stated, typically occurs within a year or so of build up of bands of scar tissue and a 37 ‘‘Of all the diseases caused by asbestos, diagnosis. Thus, like lung cancer, loss of lung elasticity (i.e., pulmonary lung cancer constitutes the greatest mesotheliomas materially impair human fibrosis).42 It is not a tumor. Following health risk for American asbestos health and functional capacity. exposure to asbestos, chronic workers.’’ OSHA (51 FR 22615–22616) As noted by ATSDR (2001), OSHA 38 inflammation may occur that leads to also stated, ‘‘* * * Asbestos exposure (1986), and many others, the multiplication of collagen-producing acts synergistically with cigarette mesotheliomas are extremely rare cells in the lung and the accumulation smoking to multiply the risk of tumors, particularly in non-asbestos of thick collagen bundles in essential developing lung cancer.’’ MSHA exposed individuals. OSHA (1986) has lung tissues.43 These structural changes believes that the essential points of this stated, ‘‘* * * In some asbestos- result in a hardening or stiffening of the statement remain true today. exposed occupational groups, 10 lungs. Physicians who specialize in Steenland et al. (2003) estimated that percent to 18 percent of deaths have diseases of the lung also classify there were about 150,000 lung cancer been attributable to malignant asbestosis as a restrictive lung disease deaths in 1997 in the United States, and mesotheliomas * * * ’’. NIOSH (May due to this loss of elasticity. that 6.3 to 13 percent (i.e., 9,700 to 2003) reported that there were about In asbestosis, the lungs are unable to 19,900) of these lung cancer deaths were 2,500 deaths due to malignant properly expand and contract during the occupationally-related. Steenland et al. mesotheliomas in the United States in breathing cycle and, thus, lung volumes, (1996) also had estimated that, in the 1999. Steenland et al. (2003) estimated airflows, and respiratory frequencies are mid-1990’s, there were about 5,400 that there were about 2,100 deaths in likely to be abnormal.44 Two common asbestos-related lung cancer deaths per the United States from mesotheliomas symptoms of this disease are cough and year. NIOSH (May 2003) identified over in 1997, and that, in males, 85–90 breathing difficulties. Patients with 10,000 lung cancer deaths in the United percent of these deaths from asbestosis may also complain of a States during 1999 based on only 20 mesotheliomas were due to general feeling of discomfort, weakness, Census Industry Codes (CIC). This sum occupational asbestos exposure. These and fatigue. Breathing difficulties, was computed from ‘‘selected states,’’ tumors were generally the underlying weakness, and fatigue are often more not the entire United States. NIOSH (primary) cause of death, and not just a severe with work or exercise. As the (May 2003) also identified 300 lung contributing cause of death. NIOSH disease progresses, patients begin to cancer deaths among coal miners from found that most mesothelioma deaths experience symptoms even while 15 selected states. were included with the categories of resting and are likely to become ‘‘all other industries’’ (56 percent) or 45 2. Mesotheliomas permanently disabled. Patients with ‘‘all other occupations’’ (57 percent). For severe asbestosis also may experience Mesotheliomas are malignant tumors those death certificates that included a heart or circulation problems, such as that are rapidly fatal. They involve thin Census Industry Code (CIC), the most heart enlargement. Like lung cancer and membranes that line the chest (the frequently recorded was ‘‘construction.’’ mesotheliomas, asbestosis may be pleura) and that surround internal The 2003 NIOSH publication, Work- progressive even in the absence of organs (the peritoneum) following Related Lung Disease Surveillance continued asbestos exposure. Thus, asbestos exposure.33 Mesotheliomas Report 2002 (WoRLD), did not provide asbestosis, even in its earliest stages, begin with a localized mass and, like specific data on mesotheliomas among constitutes a material impairment of other malignant tumors, they can spread miners. human health and functional capacity. (metastasize) to other parts of the One commenter expressed concern NIOSH (May 2003) reported that there body.34 It does not appear that smoking that the use of perchlorate in explosives were about 1,200 asbestosis-related is a major risk factor in the development might be a co-factor for increasing the deaths in the United States in 1999. Of of mesotheliomas.35 incidence or shortening the latency these, asbestosis was the underlying As in cases of lung cancer and period for mesothelioma among miners. cause in about a third of these deaths asbestosis, mesotheliomas also have a In investigating this comment, we found (400) and a contributing cause in the latency period, varying from 15 to over that perchlorate can be a component in others (800). Steenland et al. (2003) 40 years.36 Orenstein et al. (2000) explosives 39 and that perchlorate may estimated that there were about 400 reported an even wider range for the cause or contribute to thyroid disease.40 deaths from asbestosis in 1997, and that latency, from a minimum of 5 years to We found no studies linking perchlorate 100 percent of these asbestosis-deaths a maximum of 72 years. In cases to mesotheliomas. The California State were due to occupational exposure. As involving the pleura, patients often Department of Toxic Substances Control shown by NIOSH (May 2003), the complain of chest pain, breathing states that perchlorate ‘‘* * * has not number of deaths related to asbestosis difficulties on exertion, weakness, and been linked to cancer in humans increased over ten-fold between 1968 fatigue. Other early symptoms of this ***’’.41 and 1999. NIOSH also reported that disease may also include weight loss these figures likely reflect improved and cough. As the disease progresses, 37 Bolton et al., 2002; Roach et al., 2002; Osinubi diagnostic tools and the long latency there is increased restriction of the chest et al., 2000; West, 2003. period for evidence of disease that 38 Bolton et al., 2002; Britton, 2002; Carbone et wall and highly abnormal respiration, al., 2002; Manning et al., 2002; Orenstein et al., follows asbestos exposure. 2000; Roach et al., 2002; Suzuki and Yuen, 2002. 33 ATSDR, 2001. 39 EPA, 2002. 42 ATSDR, 2001. 34 Roach et al., 2002. 40 ATSDR, 1998. 43 Osinubi et al., 2000. 35 Bolton et al., 2002. 41 http://www.dtsc.ca.gov/ToxicQuestions/ 44 West, 2000; West, 2003. 36 Suzuki and Yuen, 2002. glossary.html. 45 OSHA, 1986.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00011 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 43960 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

The death certificates for most reversible airways obstruction (RAO). such as the residents of Libby, Montana; individuals who died from asbestosis Such constriction or obstruction 3 percent to 14 percent in dockyard lacked the Census Industry Code (CIC) typically involves airways in the mid to workers; and up to 58 percent among and the Census Occupation Code (COC). lower respiratory tract. insulation workers. Most asbestosis deaths were classified Several recent studies have examined Pleural plaques may develop within under ‘‘all other industries’’ (45 percent) respiratory health and respiratory 10–20 years after an initial asbestos and ‘‘all other occupations’’ (57 symptoms of asbestos-exposed exposure 55 and slowly progress in size percent). For those death certificates workers.51 Wang et al. (2001) reported and amount of calcification, that included a CIC and a COC, the most permanent changes in airway diameters independent of any further exposure. frequently recorded industry and and, thus, permanent airflow limitations There is no evidence that pleural occupation were ‘‘construction’’ (CIC = in diseases such as asbestosis or chronic plaques undergo malignant 060) and ‘‘plumbers, pipefitters, and obstructive pulmonary disease (COPD). degeneration into mesothelioma.56 steamfitters’’ (COC = 585), respectively. Although patients can recover from Pleural thickening and pleural plaques, There were no specific data on RAO, they do not recover from however, may impair lung function and asbestosis-related deaths among miners asbestosis or COPD, which are typically may precede chronic lung disease that in the NIOSH WoRLD publication (May progressive, leading to increasingly develops in some individuals.57 Rudd 2003). severe illness and premature death. (1996), for example, reported that the Delpierre et al. (2002) reported that 4. Other Cancers incidence of lung cancer in patients RAO in asbestos workers was with pleural plaques is higher than that OSHA, in its 1986 rule, reviewed independent of x-ray signs of of other patients. These plaques are also epidemiologic studies of asbestos pulmonary or pleural fibrosis, as well as part of the clinical picture of asbestosis. workers with cancer of the colon, a worker’s smoking status. The long- rectum, kidney, larynx (voice box), term implications of RAO are unknown 7. Asbestos Bodies throat, or stomach. Of these studies, at this time. Delpierre et al., however, Some asbestos-exposed individuals researchers placed the greatest emphasis encouraged physicians to screen may expel asbestos fibers from the lungs on those involving gastrointestinal asbestos workers for RAO. Lung with a coating of iron and protein. cancers. OSHA concluded, ‘‘* * * the function tests may be useful in the early These collections of coated fibers, found risk of incurring cancers at these [other] diagnosis of asbestos-disease, especially in sputum or broncho-alveolar lavage sites is not as great as the increased risk if RAO precedes the development of (BAL) fluid, are called asbestos bodies of lung cancer * * *’’. Thus, OSHA irreversible pulmonary disease, such as or ferruginous bodies.58 Like pleural included lung and gastrointestinal asbestosis. thickening and pleural plaques, these cancers, and not these other cancer 6. Other Nonmalignant Pleural Disease bodies indicate prior asbestos exposure. sites, in its 1986 risk assessment. MSHA and Pleural Plaques believes that the statement remains true D. Support From Toxicological Studies today, based on studies cited by ATSDR The pleura is the membrane lining the of Human Health Effects of Asbestos (2001) and by recent papers on kidney chest cavity. Pleural plaques are Exposure 46 47 discrete, elevated areas of nearly cancer, laryngeal cancer, Many studies are available that clearly 48 49 transparent fibrous tissue (scar tissue) lymphomas, and pancreatic cancer. demonstrate the toxicity of asbestos and are composed of thick collagen We have not attempted to quantify the (e.g., carcinogenicity, genotoxicity, bundles. Pleural thickening and pleural risks of these other cancers, which are pneumotoxicity) and confirm observed plaques are biologic markers reflecting small in comparison to lung cancer and human responses.59 Studies conducted previous asbestos exposure.52 They mesotheliomas. in baboons, mice, monkeys, and rats appear opaque on radiographic images have all demonstrated that asbestos 5. Reversible Airways Obstruction and white to yellow in microscopic fibers are carcinogenic.60 OSHA’s risk (RAO) sections.53 The American Thoracic Under normal physiological Society (ATS, 2004) has described the assessment, however, did not rely on conditions, oxygen and other inhaled criteria for diagnosis of non-malignant data from in vivo or in vitro chemical substances pass through a asbestos-related pleural disease and toxicological studies to determine the branching network of airways that pleural plaques. human health effects from exposure to become narrower, shorter, and more Pleural plaques are the most common asbestos. In the preamble to its 1986 numerous as they penetrate deeper into manifestation of asbestos exposure.54 asbestos rule (51 FR 22632), OSHA the lung.50 The diameter of each airway Only rarely do they occur in persons stated— has an important effect on its airflow. A who have no history or evidence of OSHA chose not [emphasis added] to use animal studies to predict quantitative reduction in airway diameter occurs asbestos exposure. Pleural thickening estimates of risk from asbestos exposure temporarily on exposure to some and pleural plaques may occur in because of the many high quality human chemical substances and permanently individuals exposed to asbestos in both studies available that were conducted in in some diseases. These reductions lead occupational settings, such as miners, actual workplace situations * * * OSHA has to temporary or permanent airflow and non-occupational settings, such as supplemented the human data with results limitations. A temporary reduction of family members. For example, the from the animal studies when evaluating the airway diameter and the resulting prevalence of pleural plaques ranges difficulties in breathing have also been from 0.53 percent to 8 percent in 55 Bolton et al., 2002; OSHA, 1986. called broncho-constriction, acute environmentally exposed populations, 56 Peacock et al., 2000; West, 2003. airways constriction or obstruction, or 57 Schwartz et al., 1994. 58 51 Delpierre et al., 2002; Eagen et al., 2002; Selden ATSDR, 2001; Peacock et al., 2000. 46 McLaughlin and Lipworth, 2000; Sali and et al., 2001. 59 OSHA, 1986; ATSDR, 2001. Boffetta, 2000. 52 ATSDR, 2001; Manning et al., 2002. 60 Davis et al., 1986; Davis and Jones, 1988; Davis 47 Browne and Gee, 2000. 53 Bolton et al., 2002; Manning et al., 2002; Roach et al., (in IARC) 1980; Davis et al., 1980; Donaldson 48 Becker et al., 2001. et al., 2002; Peacock et al., 2000; ATSDR, 2001. et al., 1988; Goldstein and Coetzee, 1990; McGavran 49 Ojajarvi et al., 2000. 54 Cotran et al., p. 732–734, 1999; Peacock et al., et al., 1989; Reeves, et al., 1974; Wagner et al., 1974, 50 West, 2000. 2000. 1980; Webster et al., 1993.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00012 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43961

health information and determining the A. Determining Asbestos Exposures in 1. Asbestos-Contaminated Ore Case significance of risk. Mining Study: Wollastonite Because we are relying on OSHA’s 1986 To evaluate asbestos exposures in Wollastonite is a monocalcium asbestos risk assessment for this mines, MSHA collects personal silicate found in the United States, proposed rule, we do not use the exposure air samples using a personal Mexico, and Finland. It occurs as toxicological studies for a quantitative sampling pump and a filter-cassette prismatic crystals that can split into assessment of risk, but as supportive of assembly, composed of a 50-mm massive-to-acicular (needle-like) the causative relationship between electrically conductive extension cowl fragments when processed, and is used asbestos exposure and observed human and a 25-mm diameter mixed cellulose mainly in ceramics.64 health effects. ester (MCE) filter. Following standard A consumer recently sent a sample of Toxicological studies are providing sampling procedures, we also submit the final bulk product from a important information on possible blank filters for analysis. Analysts use wollastonite mine to a commercial mechanism(s) through which asbestos the blanks to correct the sampling laboratory for analysis. When the causes disease. The ATSDR results for background fiber counts due Toxicological Profile for Asbestos to variations in the manufacturing and analysis indicated the presence of (updated 2001) contains a more detailed analysis of the filter. asbestos contamination, the consumer discussion on this topic and describes Since 2001, we have used contract informed the mine operator. The mine several mechanisms of action for laboratories to analyze our asbestos operator contacted MSHA and informed asbestos. These include— samples by PCM. The contract us of this finding after their contract laboratory confirmed the presence of • Its direct interaction with cellular laboratories report analytical results as the fiber concentration (f/cc) for each tremolite in product samples. MSHA macromolecules, then conducted industrial hygiene • filter analyzed. Then, to evaluate a Its recruitment of pulmonary miner’s full-shift exposure, MSHA sampling in the mill and the pit to macrophages that produce reactive calculates an 8-hour time-weighted verify and track the source of the oxygen and nitrogen species, and average concentration from a tremolite. We found that concentrations • Its initiation of other cellular consecutive series of individual filters. in the mill exceeded 2.0 f/cc as responses (e.g., inflammation). Several factors complicate the measured by PCM. Although asbestos averaged only about 1.3 percent of the V. Characterization and Assessment of evaluation of personal exposure levels total fibers, over half of the exposures in Exposures in Mining in mining. Non-asbestos particles collected on the filter can hide the the mill exceeded 0.1 f/cc of asbestos Asbestos minerals are widespread in asbestos fibers (overloading) and, as (the OSHA 8-hour, TWA PEL). Miners’ the environment.61 The use of asbestos- discussed earlier (see section II.C.2), exposures in the pit were much lower contaminated crushed rocks in roads, mining samples may also contain and further analyses indicated that few asbestos in insulation and other intermediate fibers that are difficult to of these samples contained asbestos. building materials, and the release of classify. (See section II.B in this The mine instituted an aggressive asbestos from brakes on vehicles preamble.) cleanup and control policy in the contributes to its presence in the B. Exposures From Naturally Occurring interest of the company and their environment. Occupational asbestos Asbestos miners’ health. This wollastonite facility exposures can be much higher than the provides and launders uniforms for the asbestos levels the public typically Mining and milling of asbestos- millers, provides physical examinations encounters. contaminated ore can release fibers into to miners and their families, and uses Miners may be exposed to asbestos in the ambient air. Beginning in January other administrative controls to limit nature, as well as in commercial 2000, we initiated a focused effort to take-home contamination. In addition to products. Mining, milling, maintenance, determine the extent of asbestos conducting personal asbestos sampling, or other activities at the mine may result exposure among miners. We chose 124 MSHA assisted mine management in the release or re-suspension of metal and nonmetal mines for sampling through the following compliance asbestos into the air.62 In some geologic based on the following: assistance activities: • Geological information linking a formations, asbestos may be in isolated • Assistance in developing cleanup pockets or distributed throughout the higher probability for asbestos contamination with certain types of ores and monitoring procedures. ore. Mining operations, such as blasting, • cutting, crushing, grinding, or simply or commodities. Discussion of hazards of asbestos • disturbing the ore or surrounding earth Historical records identifying exposure with miners and the operator. may cause the asbestos to become locations of potential problem mines. • Identification of accredited • airborne. Milling operations may Complaints from miners reporting laboratories familiar with mining transform bulk ore containing asbestos on mine property. samples to perform asbestos analyses. Asbestos tends to accumulate during asbestiform minerals into respirable • Assistance in implementation of a fibers. Similarly, other activities the milling process, which is often in enclosed buildings. The use of respiratory protection program. conducted at mine sites, such as • removing asbestos-containing materials equipment and machinery or other Instruction in recognition and during renovation or demolition of activities in these locations may re- avoidance of asbestos. MSHA and the buildings and equipment repair work,63 suspend the asbestos-containing dust mine operator worked together in may contribute to a miner’s asbestos from workplace surfaces into the air. For recognizing the problem, evaluating the exposure. this reason, we generally find higher hazard, and determining ways to control airborne concentrations in mills than exposures. This case study demonstrates successful cooperation to protect the 61 ATSDR, 2001. among mobile equipment operators or 62 MSHA (Bank), 1980; Amandus et al., Part I, in ambient environments, such as pits. health of miners. 1987. The following example supports this 63 EPA, 1986, 1993, April 2003. finding. 64 Warheit, p. 18, 1993.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00013 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 43962 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

2. Methods of Reducing or Avoiding Galbestos, which contains 7 percent and sampling times. We also allocated Miners’ Exposures to Naturally chrysotile asbestos, as indicated on the additional resources to asbestos Occurring Asbestos Material Safety Data Sheet (MSDS). sampling and analysis to verify and Some mine operators mining other Analysis of bulk samples of the debris evaluate the extent of asbestos commodities that are likely to contain left behind by the removal of the siding exposures in mining. asbestos, such as vermiculite, have confirmed that it contained chrysotile asbestos. When the miners removed it 1. Explanation of Sampling Data and stated that they are making an effort to Related Calculations avoid deposits and seams likely to without using special precautions, they contain substantial quantities of released asbestos into the air. It is The time-weighted average (TWA) asbestos. They use knowledge of the possible that these miners contaminated concentration (f/cc) for individual filters geology of the area, visual inspections of themselves with asbestos and carried it (n = 1, 2 * * *) is calculated by the working face, and sample analysis to to their families and communities (i.e., dividing the number of fibers (f) avoid encountering asbestos deposits, take-home contamination). collected on the filter by the volume of thus preventing asbestos contamination MSHA became aware of this asbestos- air (cc) drawn through the filter. of their product.65 In addition, some removal work when one of the miners TWAsum is the total time-weighted mine operators have voluntarily made a hazard complaint to the MSHA average concentration for all filters in adopted the OSHA 8-hour, TWA PEL District Office. We conducted an the series over the total sampling time. (0.1 f/cc), thus reducing the potential for investigation and determined that the The exposure limits in MSHA standards asbestos-related illness among miners. company officials had known of the are based on an 8-hour workday, potential asbestos hazard for at least 2 regardless of the actual length of the C. Exposures From Introduced years. We found no asbestos in the shift. MSHA measures the miner’s (Commercial) Asbestos personal air samples collected after the exposure for the entire time the miner Asbestos is an important component siding had been removed. Although we works. We then calculate a full-shift in some commercial products and may did not issue citations for overexposure airborne exposure concentration as if be found as a contaminant in others. to asbestos, we issued citations to the the fibers had been collected over an 8- Due to improved technology and company for failure to implement hour shift. This allows us to compare increased awareness, however, special work procedures, failure to issue the miner’s exposure to the 8-hour substitutes for asbestos in products are appropriate personal protective TWA, full-shift exposure limit. MSHA available for almost all uses, and equipment, and failure to train the calls this calculated 8-hour TWA a manufacturers have removed the affected miners for the task. The mine ‘‘shift-weighted average (SWA).’’ 66 operator took corrective action and we asbestos from many new products. We calculate the TWAsum and SWA Nevertheless, there are mines, including terminated these citations. exposure levels for each miner sampled coal mines, that have introduced 2. Methods of Reducing or Avoiding according to the following formulas, commercial asbestos-containing Miners’ Exposures to Introduced respectively. products on their property. Some of (Commercial) Asbestos TWAsum = (TWA1t1 + TWA2t2 + *** these introduced products may include + TWA t )/(t + t + * * * + t ) asbestos-containing building materials, Existing Federal and state standards n n 1 2 n  already address the removal of asbestos- SWA = (TWA1t1 + TWA2t2 + * * * + such as Transite board, used during TWA t )/480 minutes construction, rehabilitation, or containing building materials (ACBM). n n demolition projects. Other examples of If the asbestos-containing material is Where: intact, it is preferable to leave it where introduced commercial products that TWAn is the time-weighted average may contain asbestos are brake linings it is. If the asbestos-containing material concentration for filter ‘‘n’’. is worn or deteriorating, these standards for mining equipment, insulation, joint tn is the duration sampled in minutes for and packing compounds, and asbestos require the use of special precautions filter ‘‘n’’. (e.g., personal protective equipment, welding blankets. TWAntn is the time-weighted average Occasionally, miners report incidents training, decontamination) to prevent or concentration for filter ‘‘n’’ of possible asbestos release through minimize exposure of workers and the multiplied by the duration sampled MSHA’s Hazard Complaint Program. public and contamination of the for filter ‘‘n’’. environment. We train our inspectors to Inspectors also report mines with (t1 + t2 + * * * + tn) is the total time noticeably deteriorated asbestos- encourage mine operators to have worn sampled in minutes. containing building materials (ACBM). or deteriorating asbestos-containing We investigate these reported situations products removed by persons specially MSHA defines a ‘‘sample’’ as the and take appropriate action. The trained to remove the asbestos- average 8-hour full-shift airborne following example describes an incident containing material safely. concentration that represents an individual miner’s full-shift exposure. in which miners unsafely removed D. Sampling Data and Exposure asbestos at a mining operation. The following information from our Calculations database illustrates the sampling results 1. Introduced Asbestos Case Study: After the national publicity from these calculations. For one Potash surrounding asbestos-related diseases mechanic at the potash mine in our In June 2003, eight miners removed and death among the population of previous example, MSHA used a series siding on three transfer conveyors Libby, Montana, MSHA closely of three filter-cassettes to determine the originally installed in 1962 at a potash reviewed and updated its asbestos- miner’s full-shift exposure. We sampled mine in Utah. The siding was weathered related health procedures and policies a total of 577 minutes. The highest TWA and deteriorated to the point of being for metal and nonmetal mines. We then concentration for one filter-cassette in friable (crumbling). The type of siding made sure these procedures and policies this series was 4.100 f/cc as analyzed by was a commercial product named were applied consistently across the PCM. MSHA calculated the mechanic’s country. For example, we switched from full-shift exposure to report the fiber 65 GETF Report, pp. 17–18, 2003. a 37-mm to a 25-mm filter cassette and concentration as if the mechanic had 66 GETF Report, pp. 12 and 15, 2003. recommended appropriate flow rates received the full exposure in 8 hours

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00014 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43963

(480 minutes). The mechanic’s shift- 2. Summary of MSHA’s Asbestos United States (Joe 5 Pit in California) weighted average (SWA) was 1.982 f/cc. Sampling and Analysis Results closed in December 2002 and its To assess exposures and present our associated mill (King City) closed in TABLE V–1.—EXAMPLE OF PERSONAL asbestos sampling results to the public, June 2003, we excluded those data in SAMPLING RESULTS we compiled our asbestos sampling data our analysis. for the period January 1, 2000 through Of the remaining 123 mines that Mechanic PCM TWA December 31, 2003. We formatted these MSHA sampled during this 4-year sampled 6/ Sampling time fiber data into four Excel workbooks, one for 17/2003 at (minutes) concentration period, 18 mines could be potentially 1.7 Lpm (f/cc) each year, and placed them, together impacted by the lowering of the full- with additional explanatory shift permissible exposure limit to 0.1 f/ information, on our Asbestos Single Filter-cas- cc as measured by PCM. These 18 mines Source Page at http://www.msha.gov/ sette 1 ... 230 4.100 have had at least one miner exposed to Filter-cas- asbestos/asbestos.htm. sette 2 ... 252 0.016 We calculated an 8-hour full-shift airborne fiber concentrations exceeding Filter-cas- exposure for each miner sampled from 0.1 f/cc during this period. Two of the sette 3 ... 95 0.045 the TWA of individual filters, typically 18 mines (iron ore and wollastonite) had TWAsum re- three filters per shift. These data include personal asbestos exposures confirmed sult ...... 577 1.649 the results of 703 full-shift personal by TEM exceeding 0.1 f/cc. Excluding Sample exposure samples, comprised of 2,184 the 42 samples from the asbestos mine (SWA) filter-cassettes, and cover 163 industrial and mill, 8 percent of the remaining 661 result ..... 480 1.982 hygiene sampling visits at 125 mines personal samples had 8-hour TWA, full- (124 metal and nonmetal mines and one shift fiber concentrations greater than coal mine), including some mines and the proposed 0.1 f/cc PEL, as measured mills that are now closed. Because the by PCM. Table V–2 below summarizes last remaining asbestos mine in the these sampling results.

TABLE V–2.—PERSONAL EXPOSURE SAMPLES, ANALYZED BY PCM, AT CURRENTLY ACTIVE MINES 1 BY COMMODITY (1/ 2000–12/2003)

Number of Number (%) of Number of Number (%) of Commodity mines mines samples samples sampled >0.1 f/cc SWA >0.1 f/cc SWA 2

Rock & quarry products 3 ...... 61 4 (7%) 215 7 (3%) Vermiculite ...... 4 3 (75%) 127 5 (4%) Wollastonite ...... 1 1 (100%) 18 18 (100%) Iron (taconite) ...... 14 5 (36%) 178 17 (10%) Talc ...... 12 1 (8%) 38 2 (5%) Boron ...... 2 1 (50%) 9 4 (44%) Other 4 ...... 29 5 3 (10%) 76 3 (4%)

Total ...... 123 6 18 (15%) 661 56 (8%) 1 Excludes data from a closed asbestos mine and mill. 2 MSHA uses TEM to confirm the presence of asbestos on samples showing exposures exceeding 0.1 f/cc. 3 Including stone, sand and gravel mines. 4 Coal, potash, gypsum, salt, cement, clay, lime, mica, metal ore NOS, olivine, shale, pumice, trona, perlite, and gold. 5 Coal, potash, and gypsum (Coal and potash personal exposures are due to commercially introduced fiber release episodes, i.e., not from a mineral found at the mine). 6 TEM confirmed asbestos exposures exceeding 0.1 f/cc in two of the 18 mines.

MSHA is proposing to lower its 8- VI. The Application of OSHA’s Risk found that these additional studies hour TWA, full-shift PEL from 2.0 f/cc Assessment to Mining confirm OSHA’s conclusions. to 0.1 f/cc to provide increased Section VIII of this preamble contains protection for miners. As noted in We are applying OSHA’s risk assessment to our exposure sampling a summary of our findings from OSHA’s risk assessment for its 1986 applying OSHA’s quantitative asbestos rule, there is significant risk of data on miners to estimate the risk from asbestos exposure in mining. In assessment of risk to the mining material impairment of health or industry. The Preliminary Regulatory functional capacity even at this lower response to the ANPRM, the National Mining Association (NMA) expressed Economic Analysis (PREA) contains a PEL. MSHA compliance data indicate more in-depth discussion of our that some miners’ asbestos exposures their belief that health risk is related to fiber type and that OSHA’s risk methodology and conclusions. We have exceeded 0.1 f/cc. Available data placed our PREA in the rulemaking from death certificates in 24 states assessment is no longer adequate or appropriate for us to use for the mining docket and posted it on our Asbestos confirm that there is asbestos-related Single Source Page at http:// mortality among miners.67 industry. In developing this proposed rule, we evaluated studies published www.msha.gov/asbestos/asbestos.htm. over the last 20 years since OSHA We also placed OSHA’s risk assessment completed its risk assessment, and in the rulemaking docket. studies that specifically focused on asbestos exposures of miners. We have 67 NIOSH World, p. E–1, 2003.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00015 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 43964 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

A. Summary of Studies Used by OSHA involving three occupational cohorts, EPA, in its Integrated Risk in Its Risk Assessment for asbestosis. We briefly review these Information System (IRIS), presents a studies below, since they also serve as useful table summarizing data from lung OSHA relied on eight non-mining and the basis of our risk assessment. For cancer and mesothelioma studies. We milling studies to estimate the risk of completeness, we are including Table extracted that portion of their table lung cancer due to asbestos exposure. VI–1 of some mining and milling dealing with the studies included in They used four studies to estimate the studies that have been conducted. OSHA’s risk assessment. This is the risk of mesotheliomas, and two studies, basis for Table VI–1 below.

TABLE VI–1.—SUMMARY OF LUNG CANCER AND MESOTHELIOMA STUDIES

Reported Percent (%) average increase in Human data occupational group Fiber type exposure cancer per Reference (f-yr/mL) f-yr/mL

Lung Cancer

Friction Products ...... Chrysotile ...... 32 0.058 Berry and Newhouse, 1983. Textile Products ...... Mostly Chrysotile ...... 44 2.8 Dement et al., 1982. Cement Products...... Mixed (Amosite, Chrysotile, 112 6.7 Finkelstein, 1983. Crocidolite).

Asbestos Products...... Mixed (Amosite, Chrysotile, 374 0.49 Henderson and Enterline, 1979. Crocidolite). Textile Products ...... Chrysotile ...... 200 1.1 Peto, 1980. Insulation Products ...... Amosite ...... 67 4.3 Seidman et al., 1979; Seidman, 1984. Insulation Workers...... Mixed (Amosite, Chrysotile, 300 0.75 Selikoff et al., 1979. Crocidolite). Cement Products...... Mixed (Amosite, Chrysotile, 89 0.53 Weill et al., 1979. Crocidolite).

Mesotheliomas

Cement Products...... Mixed (Amosite, Chrysotile, 108 1.2 E–5 Finkelstein, 1983. Crocidolite). Textile Products ...... Chrysotile ...... 67 3.2 E–6 Peto et al., 1982. Insulation Products ...... Amosite ...... 400 1.0 E–6 Seidman et al., 1979; Seidman, 1984. Insulation Workers...... Mixed (Amosite, Chrysotile, 375 1.5 E–6 Selikoff et al., 1979. Crocidolite).

1. Lung Cancer typically exceeded 20 f/mL throughout fiber other than chrysotile was ever the factory. From 1932–1969, asbestos processed.’’ The men in this study had a. Berry and Newhouse, 1983 levels decreased and most exposures at least 1 month of employment between Berry and Newhouse (1983) ranged from 2–5 f/mL. After 1970, levels January 1, 1940 and December 31, 1965. conducted a retrospective mortality decreased to below 1 f/mL. Dement et al. then followed the cohort study (1942–1980) using data from an Berry and Newhouse (1983) did not for another 10 years. English factory that manufactured detect excessive mortality at this factory Air samples were collected in this asbestos-containing friction materials over the period 1942 to 1980. OSHA factory between 1930 and 1975 to (e.g., brake blocks, stair treads). There noted, however, the relatively short determine asbestos levels. Impinger were 13,460 workers included in this duration of employee exposures and the samples were collected prior to 1965; study, of which two-thirds were men. short follow-up period (e.g., less than 20 then membrane filter sampling was Most had worked in this factory for 2– years for 33 percent of the men). In the introduced. Membrane filter sampling 10 years. The asbestos exposures preamble to their 1986 asbestos rule, fully replaced the impinger method in generally involved chrysotile, although OSHA stated, 1971. There were 193 air samples this site also had used crocidolite for * * * Because of the short follow-up period collected in 1930–1945, 183 in 1945– two brief periods, one from 1922–1933 used, OSHA does not believe that the non- 1960, and 5,576 in 1960–1975. The and a second from 1939–1944. significant increases in lung cancer mortality estimated mean asbestos exposure levels Personal air sampling for the found by these investigators [Berry and by job and calendar time periods, using Newhouse] contradict the findings from other linear regression models, were as high assessment of asbestos concentrations in studies which show that low-level exposure this factory began in 1968. Fiber levels to asbestos has resulted in excessive as 78 f/cc before 1940 and generally for time periods prior to 1968 were mortality from lung cancer * * * ranged from 5–10 f/cc after 1940. ‘‘estimated by reproducing earlier work Dement et al. (1982) demonstrated a conditions using detailed knowledge of b. Dement et al., 1982 linear dose-response relationship for when processes were changed and Dement et al. (1982) conducted a lung cancer mortality that did not exhaust ventilation introduced.’’ retrospective cohort mortality (1930– appear to have a threshold. They also Asbestos fiber concentrations were 1975) study of 768 men. These men had found a linear dose-response determined over four time periods: Pre- worked in an asbestos textile factory relationship for non-malignant 1931, 1932–1950, 1951–1969, and 1970– located in South Carolina where ‘‘only respiratory disease, other than upper 1979. Before 1931, asbestos levels an insignificant quantity of asbestos respiratory infection, influenza,

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00016 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43965

pneumonia, or bronchitis. Like the lung d. Henderson and Enterline, 1979 replaced by membrane filters. In this cancer data, the dose-response In 1979, Henderson and Enterline study, Peto revised earlier estimates of relationship for non-malignant published an update of their 1941–1967 asbestos exposure concentrations and respiratory disease did not appear to mortality study. The extended study reported mean levels in fibers/mL for have a threshold. provided data through 1973 and six selected years as follows: 32.4 OSHA’s 1986 rulemaking considered included 1,075 men who had worked (1951), 23.9 (1956), 12.2 (1961), 12.7 that Dement et al.’s report of excess risk for an asbestos company in the United (1966), 6.7 (1971), and 1.1 (1974). Peto et al. then used these values to calculate at low cumulative [asbestos] exposures States for an average of 25 years. Most cumulative exposures. The average was well supported because of their of the workplace exposures involved cumulative exposure for men first ‘‘* * * careful estimation of exposure chrysotile, although some involved exposed to asbestos during or after 1951 histories for members of the cohort amosite or crocidolite. (i.e., Cohort 2) was 200–300 fiber-years/ ***’’. Henderson and Enterline conducted mL. c. Finkelstein, 1983 impinger sampling to determine Peto (1980) confirmed earlier asbestos levels for this study and conclusions by Doll (1955) and Peto et Finkelstein (1983) studied a group of reported asbestos concentrations in al. (1977) that there was excess lung 328 men who worked in an Ontario, millions of particles per cubic foot cancer mortality in this asbestos textile Canada, factory that manufactured (mppcf). They also identified five factory. Although Peto et al. (1977) asbestos-cement pipe and rock-wool cumulative exposure categories (87, 255, suggested a dose-response relationship insulation. Men selected to participate 493, 848, and 1,366 fiber-years/cc) by for lung cancer using measurements in this study began working at the converting their original data, reported from a static dust sampler, Peto did not factory prior to 1961 and worked for the in mppcf, to f/cc using a factor of 1:1.4 demonstrate such a dose-response company for at least 9 years. Finkelstein as discussed in the 1986 OSHA asbestos relationship in this later study (1980). divided the men into three groups based rule (51 FR 22617). on estimated levels of asbestos For the period 1941–1973, Henderson f. Seidman et al., 1979 (With Update to exposure: 186 in production (consistent and Enterline (1979) found that this OSHA in 1984) exposure), 55 in maintenance cohort had an overall mortality rate that Seidman et al. (1979) conducted a (intermittent exposure), and 87 controls was about 20 percent higher than that of mortality study (1946–1977) of 820 men (minimal exposure). The asbestos males in the general population. This who worked in an amosite factory in exposures involved chrysotile and increase in mortality rate was mainly New Jersey. This factory supplied the crocidolite, both of which the factory due to lung cancer and other respiratory U.S. Navy with insulation for pipes, mixed with cement and silica. This diseases. boilers, and turbines. The men in this study report did not indicate the OSHA (1986) noted that the excess study were first employed between 1941 proportions of asbestos and silica used mortality risk found by Henderson and and 1945 and were followed for 35 in the cement. Enterline (1979) was less than that years. Due to wartime conditions, Air samples were collected to assess found by Dement et al. (1982). however, there was a changing asbestos levels at this cement factory. Henderson and Enterline, however, composition of the workforce. Seidman Impinger sampling was conducted studied retired asbestos workers, which et al. (1979) stated that— between 1943 and 1968. In 1969–1970, ‘‘constitute a select group of survivors’’ This resulted in a unique experience; men the factory began to use the personal (51 FR 22617), and which might explain with a very limited duration of intense membrane filter sampling method and the difference in results of these two exposure to Amosite asbestos, followed by used this sampling data to classify the mortality studies. long observation * * * men who worked in cement production e. Peto, 1980 The men were classified according to according to their probable cumulative the time in which they came into direct asbestos exposure. They used three sub- Peto (1980) continued the study of contact with the amosite: Less than 1 groups (A, B, C) of estimated exposure workers in an asbestos textile factory in month, 1 month, 2 months, 3–5 months, ranges and means as follows: England. His paper, published in 1980, 6–11 months, 1 year, or 2 or more years. was an extension of two earlier reports, Thus, this cohort is unlike those of other CUMULATIVE EXPOSURE one by Doll (1955) and a second by Peto studies where workers were exposed to [Fiber-years/mL] et al. (1977). In this updated study asbestos for long periods, often 20 or (1980), Peto included 679 men who more years. Range Mean were hired in 1933 or later, and who In this amosite factory, there were no had been employed by the company for direct measurements of asbestos levels. Subgroup A ...... 8–69 44 at least 10 years by 1972. Peto divided The determination of asbestos Subgroup B ...... 69–121 92 the workers into two cohorts: those first concentrations was made solely by Subgroup C ...... 122–420 180 exposed before 1951 (Cohort 1, n = 424 analogy with another factory in which men) and those first exposed during or air sampling was done in the late 1960’s Finkelstein also relied on detailed after 1951 (Cohort 2, n = 255 men). The and in the 1970’s. Seidman et al. employment histories and medical National Health Central Register and reported that, in samples taken in this records for each man in the study. factory personnel followed the workers latter factory in October of 1971, Finkelstein (1983) found that the until 1978. The exposures in this textile asbestos counts averaged as high as 23 asbestos-exposed workers had all-cause factory involved chrysotile. f/mL. mortality rates that were twice that of Although routine measurements of Seidman et al. (1979) demonstrated the general Ontario population. He also asbestos levels were not made prior to that the amosite workers were at risk of reported that the mortality rates due to 1951, Peto et al. (1977) had estimated developing lung cancer and dying from malignancies and the deaths attributable the workers’ exposures in an earlier this disease. Seidman et al. (1979) to lung cancer were five and eight times study. Between 1951 and 1961, a concluded that— those of the general population, thermal precipitator was used to sample • Prolonged follow-up is necessary to respectively. for asbestos, then was gradually evaluate the effects of asbestos on

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00017 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 43966 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

health, especially with lower categories,’’ each including a 5-year age (1979), however, did not provide the concentration or shorter duration span (e.g., 15–19 years, 20–24 years, proportion of silica in the asbestos exposures. etc.) Those men age 85 or older were cement mixture. • Asbestos retained in tissues may grouped together. The investigators Impinger sampling was conducted in continue to produce adverse effects long identified the time at which each man this factory to determine asbestos levels. after the exposure may have stopped. was first exposed to asbestos and then The sampling results were reported in • The length of the latency period for separated the data into a series of millions of particles per cubic foot asbestos-related diseases depends categories based on how long it had (mppcf). Based on sampling data, Weill directly on the dosage and the age at been since their first exposure (e.g., less et al. (1979) defined five categories of which exposure takes place. For than 20, 20–34, and 35 or more years exposure in mppcf/year as follows: Less example, older workers will show a ago). than 10, 11–50, 51–100, 101–200, and more pronounced and quicker effect Selikoff et al. (1979) reported that few more than 200. OSHA (51 FR 22618) than younger workers with the same measurements were made to assess converted the original data of Weill et level of exposure. asbestos levels in insulation work until al. (1979) from mppcf/year to fiber- • The longer the time after first the mid-1960’s. For this reason, they years/cc using a factor of 1:1.4, as given exposure to asbestos, the more estimated exposure levels using in the 1986 OSHA rule (51 FR 22617). pronounced the excesses in mortality. reconstructions of past work conditions This yielded the following exposure • Reducing the asbestos exposure and extrapolations of more current categories in fiber-years/cc: Less than (lowering the dosage) can both delay the measurements to past conditions. They 14, 15–70, 71–140, 141–280, more than occurrence of adverse effects (e.g., time concluded that insulation workers 280. to death) and lower the frequency of would have been exposed to TWA Weill et al. (1979) found excess their occurrence (e.g., fewer deaths). concentrations of 4–12 f/mL. mortality due to cancers, mainly lung In 1984, Seidman updated his earlier Selikoff et al. (1979) concluded that cancer, in men whose cumulative work by adding 593 cases involving the asbestos insulation workers were at exposures were moderate (141–280 deaths that occurred 5–40 years beyond ‘‘extraordinary increased risk of death of fiber-years/cc) to high (greater than 280 each man’s first amosite exposure. cancer and asbestosis.’’ The study had fiber-years/cc). About 25 percent of their Seidman again developed a found an excessive number of lung cohort, however, was lost in the follow- classification scheme, but now he based cancers (486) in this cohort, particularly up period. For the purpose of the study, it on cumulative exposure to amosite at 15–35 years after the first exposure to Weill et al. assumed they were alive. and not on time alone. The exposure asbestos. This figure was even more This assumption may have led to an categories were less than 6, 6–11.9, 12– striking when compared to the expected underestimation of lung cancer risk. For 24.9, 25–49.9, 50–99.9, 100–149.9, 150– number of lung cancer cases (106) for this reason, OSHA (51 FR 22618) stated 249.9, and 250 or more fiber-years/cc. this same group of men. its opinion as follows: Using this new information, he was able h. Weill et al., 1979. * * * the presence of an excess risk of to demonstrate an exposure-response mortality from lung cancer could not be ruled relationship for lung cancer mortality. Weill et al. (1979) conducted a out for the cohorts in these exposure mortality study of 5,645 men who had g. Selikoff et al., 1979. categories. [The other three, lower exposure at least 1 month of continuous categories defined by Weill et al., 1979.] Selikoff et al. (1979) conducted a employment before January 1, 1970 in mortality study (1943–1976) of 17,800 one of two asbestos cement building 2. Mesotheliomas men who belonged to the insulation materials plants in New Orleans, a. Finkelstein, 1983. workers’ union. Members of this Louisiana. The men in this study had We reviewed the most important insulation union worked mainly in worked at some time during the 1940’s aspects of this study above. (See section construction in the United States and to the mid-1970’s. The investigators VI.A.1.) Based on death records, Canada, but some worked in refineries, followed this cohort for at least 20 years Finkelstein (1983) found 11 industrial plants, shipyards, and power and found that— mesotheliomas among the total of 58 plants. Selikoff et al. (1979) described For both plants, 7 percent [of the men] deaths in his study. The mean age at the content of the asbestos insulation as were initially employed before 1940, 76 which these men were first exposed to follows. percent during the 1940s, and 17 percent asbestos was 25 years, and their mean Until approximately the early 1940s, during 1950 to 1954. Sixty percent were latency period for mesotheliomas was chrysotile alone was utilized in the employed for less than one year, 24 percent 25 years. The mean age at death was 51 manufacture of the asbestos insulation for one to 10 years, and 16 percent for more years, and none was over 60 years. This products used by these men. Amosite began than 10 years. demonstrates that death follows quickly to be used in the mid-1930s in small The asbestos exposures mainly after this disease becomes evident. quantities but became more widely utilized involved chrysotile, although the two Finkelstein noted that the rates of during World War II and subsequently. plants also processed crocidolite and death from mesotheliomas were The ages of men in this study ranged amosite. The cement products were proportional to the magnitude of from 15 to over 85 years and Selikoff et comprised of about 15–28 percent cumulative asbestos exposure, as shown al. (1979) established a series of ‘‘age asbestos and some silica. Weill et al. in Table VI–2 below.

TABLE VI–2.—MESOTHELIOMAS MORTALITY RATES COMPARED TO EXPOSURE

Estimated Mesotheliomas exposure Estimated mortality rates range mean (per 1,000 man-years) (fiber-years/ exposure mL) fiber-years/mL)

1.9 ...... 8–69 44

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00018 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43967

TABLE VI–2.—MESOTHELIOMAS MORTALITY RATES COMPARED TO EXPOSURE—Continued

Estimated Mesotheliomas exposure Estimated mortality rates range mean (per 1,000 man-years) (fiber-years/ exposure mL) fiber-years/mL)

4.9 ...... 70–121 92 11.9 ...... 122–420 180

Based on the exposure-response data, important, but until carcinogenic effects of 3. Asbestosis such differences have been demonstrated, it Finkelstein concluded, ‘‘* * * the a. Berry and Lewinsohn, 1979. relation is compatible with a linear would seem sensible to concentrate on fibre dimension rather than mineral type in Berry and Lewinsohn (1979) studied function through the origin * * *.’’ the same group of textile workers that Accordingly, Finkelstein’s data suggest developing dose-response relationships. * * * It may therefore be dangerously was originally described by Berry et al. the lack of a threshold for optimistic to attribute the substantial (1979) and, thus, a short summary of the mesotheliomas. incidence of pleural mesothelioma among original paper is presented here. b. Peto et al., 1982. chrysotile factory workers to occasional Berry et al. (1979) studied a group of Peto et al. (1982) evaluated crocidolite exposure * * * 379 men who worked in an asbestos mesothelioma mortality (1967–1979) in textile factory located in northern the same group of 17,800 insulation c. Seidman et al. 1979 (With Update England. Most of the worker exposures workers previously described by to OSHA in 1984). involved chrysotile, although this site Selikoff et al. (1979). We reviewed the We reviewed the salient features of also used crocidolite. Asbestos fiber salient features of Selikoff et al. (1979) this study and its update above. (See levels were measured in this factory above. (See section VI.A.1.) Members of section VI.A.1.) Based on death records, since 1951 and had been estimated this insulation workers’ union worked Seidman et al. (1979) found 14 since 1936. Berry et al. defined two in the United States and Canada and mesotheliomas among the total 528 cohorts. One included men who were were exposed to chrysotile and amosite. deaths in their study. They reported an first employed between 1933 and 1950, Peto et al. (1982) reported ‘‘a high additional three mesotheliomas in their and were still working in this textile incidence’’ of mesotheliomas in this update. OSHA commented that this was factory in 1966. The other included men cohort. There were 236 deaths from ‘‘a finding of great significance given the who were employed after 1966, and had mesotheliomas, of which 87 were rarity of the disease’’ (51 FR 22617). worked for at least 10 years in this pleural and 149 were peritoneal. They d. Selikoff et al. (1979). textile factory. Berry et al. (1979) found closely examined each man’s age at the relationships between cumulative first asbestos exposure and the number The salient features of this study were asbestos exposure and crepitations of years since his first exposure. Peto et reviewed above. (See section IV.A.1.) (abnormal lung sounds), possible al. (1982) concluded that mesothelioma Based on death records, Selikoff et al. asbestosis, and certified asbestosis. mortality was strongly dependent on the (1979) found 38 mesotheliomas (pleural As noted above, Berry and Lewinsohn number of years since the first asbestos and peritoneal) in their initial cohort of (1979) used data from the same textile exposure, but was independent of the 632 asbestos insulation workers. There factory as that described by Berry et al. age at the first exposure. They stated— were 223 deaths in this part of their (1979); but Berry and Lewinsohn (1979) study (1943–1976). Some of these defined two different cohorts. One deaths from mesotheliomas occurred Mesothelioma death rates in asbestos included men who were first employed workers appear to be proportional to the 20–34 years after the first exposure to before 1951. The other included men third or fourth power of time * * * Age at asbestos, described by the authors as first employed after 1950. Berry and first exposure has little or no influence, ‘‘duration from onset.’’ For most men Lewinsohn (1979) plotted the incidence however, which supports the multi-stage who died from mesotheliomas, of cases of possible asbestosis against model of carcinogenesis * * * however, it was 35 or more years after the cumulative asbestos exposure up to mesotheliomas may constitute a high their first exposure. 1966. They stated— proportion of cancer deaths resulting from early exposure to asbestos. In the second and much larger cohort The data are compatible with a linear (n = 17,800) of Selikoff et al. (1979), relationship through the origin [indicating no Peto et al. (1982) also reviewed there were 175 deaths due to threshold], with no statistically significant mesothelioma mortality data from mesotheliomas of the total 2,271 deaths difference between the two groups [cohorts]. several other studies in addition to in this group. Some (14) of these deaths b. Finkelstein, 1982. those from Selikoff et al. (1979). They caused by mesotheliomas occurred 15– Finkelstein (1982) studied a group of were interested in determining if they 24 years after the first asbestos 201 men who worked in a factory in could establish a relationship between exposure, while most (161) were Ontario, Canada, that manufactured deaths from mesotheliomas and fiber recorded 25 or more years after the first asbestos-cement pipe and rock-wool type. Although there were some data to exposure. Selikoff et al. (1979) had been insulation. Finkelstein defined two suggest that deaths from mesotheliomas unable to provide expected death rates subsets in his study population: A group were more common in men who worked for mesotheliomas due to their rarity in of 157 production workers and a group with amphiboles (e.g., crocidolite), Peto the general population. This study of 44 maintenance workers. The men et al. (1982) were cautious when demonstrated an unequivocal selected to participate in this study drawing conclusions. They stated that— association between mesotheliomas and worked in the pipe or board shop for at prior asbestos exposure. In the 25 years least one year prior to 1961 and had Chemical [and physical] differences since this paper was published, there been employed at least 15 years. Most between different fibre types may also be has been no evidence to the contrary. of the asbestos exposures involved

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00019 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 43968 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

chrysotile and crocidolite, both of RL = Predicted lung cancer mortality. for the bias in its analysis and avoid which were mixed with cement and RE = Expected lung cancer mortality in overestimation of mesotheliomas in silica. the absence of asbestos exposure. their risk assessment. Between the 1940’s and 1968, KL = Slope of the dose-response ¥8 impinger sampling was conducted to relationship for lung cancer. Study KM(10 ) assess total dust levels. In 1969/1970, f = Asbestos fiber concentration (f/cc). the company began to conduct quarterly d = Duration of the exposure (minus 10 Finkelstein, 1983 ...... 12 personal sampling for asbestos using the years to account for latency). Peto et al., 1982 ...... 0.7 membrane filter method. Finkelstein Seidman et al., 1979; The following list gives the KL values Seidman, 1984 ...... 5.7 used the results of such sampling as for the eight studies used by OSHA. Selikoff et al., 1979 ...... 1.0 baseline values for various jobs. OSHA (51 FR 22637) used KL = 0.01, the Of the workers in this study, 39 geometric mean of these eight studies, 3. Asbestosis percent of those in production and 20 in their risk assessment. percent of those in maintenance had For asbestosis, OSHA (1986) relied on

certified asbestosis. Finkelstein Study KL an absolute risk model that was linear demonstrated that there was a in cumulative dose. The following relationship between cumulative Berry and Newhouse, 1983 .... 0.0006 equation describes the lifetime asbestos exposure and certified Dement et al., 1982 ...... 0.042 incidence of asbestosis: Finkelstein, 1983 ...... 0.048 asbestosis. He describes the exposure- RA = m(f)(d) response curve as sigmoidal, a shape Henderson and Enterline, 1979 ...... 0.0047 Where: commonly observed in toxicology. The Peto, 1980 ...... 0.0076 curve also appears to intersect the RA = Predicted lifetime incidence of Seidman et al., 1979; asbestosis. origin, which suggests a lack of Seidman, 1984 ...... 0.045 threshold. Selikoff et al., 1979 ...... 0.020 f = Asbestos fiber concentration. Weill et al., 1979 ...... 0.0033 d = Duration of the exposure. B. Models Selected by OSHA (1986) for m = Slope of the linear regression. Specified Endpoints and for the Determination of Its PEL and STEL 2. Mesotheliomas OSHA stated (48 FR 51132), ‘‘the best For mesotheliomas, OSHA (1986) estimates of asbestosis incidence are Based on their critical review of the derived from the Finkelstein data ‘‘and studies described above (see section relied on an absolute risk model that is linear in dose, but exponentially related OSHA did not rely on the values for the VI.A), OSHA (51 FR 22631) slope as determined by Berry and concluded— to the time after the first exposure to asbestos. The following three equations Lewinsohn (1979). Thus, based on * * * asbestos exposure causes lung describe the risk. Finkelstein’s data (1982) alone, the disease, respiratory cancer, mesothelioma, slope (m) is 0.055 and the equation and gastrointestinal cancer. * * * excess 3 ¥ 3 ARM = (f)(KM)[(t-10) (t-10-d) ], for t becomes RA = 0.055(f)(d). disease risk has been observed at cumulative > 10 + d Using this linear model, OSHA also exposures at or below those permitted by the 3 ARM = (f)(KM)[(t-10) ], for 10 + d > t > calculated estimates of lifetime existing OSHA 8-hour permissible exposure 10 limit [PEL] of 2 f/cc. In addition, OSHA has asbestosis incidence at five exposure made risk estimates of the excess mortality ARM = 0, for 10 > t levels of asbestos (i.e., 0.5, 1, 2, 5, 10 f/ from lung cancer, mesothelioma, Where: cc) and published Table VI–3 (48 FR gastrointestinal cancer, and the incidence of RM = Excess risk of mesotheliomas. 51132), which we have reproduced asbestosis using mathematical models * * * f = Asbestos fiber concentration. below. OSHA concluded that for The following is a summary of the KM = Slope of the dose-response lifetime exposures to asbestos at mathematical models that OSHA used relationship for mesotheliomas. concentrations of 2 or 0.5 f/cc, there in its asbestos risk assessment. d = Duration of the exposure. would be a 5 percent or a 1.24 percent t = Time after the first exposure to incidence of asbestosis, respectively (48 1. Lung Cancer asbestos. FR 51132). Based on Finkelstein’s linear For lung cancer, OSHA (1986) relied The following list gives the KM values relationship for lifetime asbestosis on a relative risk model that was linear for the four studies used by OSHA. incidence, OSHA later stated (51 FR in dose, as described by the following OSHA (51 FR 22640 and 22642) used 22646) that, ‘‘Reducing the exposure to ¥8 equation: KM = 1 × 10 , the ratio of KM/KL, rather 0.2 f/cc [a concentration not included in ¥8 RL = RE[1 + (KL)(f)(dt-10)] than KM = 2.91 × 10 , the geometric Table VI–3] would result in a lifetime Where: mean of these four studies, to account incidence of asbestosis of 0.5%.’’

TABLE VI–3.—ESTIMATES OF LIFETIME ASBESTOSIS INCIDENCE

Percent (%) Incidence Exposure level, fiber/cc Berry (em- Berry (first em- Finkelstein ployed before ployed after 1951) 1950)

0.5 ...... 1.24 0.45 0.35 1 ...... 2.49 0.89 0.69 2 ...... 4.97 1.79 1.38 5 ...... 12.43 4.46 *3.45 10 ...... 24.86 8.93 6.93 Slope ...... 0.055 0.020 0.015

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00020 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43969

TABLE VI–3.—ESTIMATES OF LIFETIME ASBESTOSIS INCIDENCE—Continued

Percent (%) Incidence Exposure level, fiber/cc Berry (em- Berry (first em- Finkelstein ployed before ployed after 1951) 1950)

R2 ...... 0.975 0.901 0.994 * Note: 1.38 in original table was a typographical error. The text (48 FR 51132) and the regression formula indicate that 3.45 is the correct percent.

C. OSHA’s Selection of Its PEL (0.1 f/cc) concentration and duration of related cancer decreases significantly by exposure). These data were published in lowering exposure. This is true Using the models described above in its 1986 risk assessment (51 FR 22644), regardless of the type of cancer: lung, section VI.B., OSHA estimated cancer which we have reproduced in the pleural, peritoneal, or gastrointestinal. mortality for workers exposed to following Table VI–4. Although excess relative risk is linear in asbestos at various cumulative It is clear from Table VI–4 that the dose, the excess mortality rates in Table exposures (i.e., combining exposure estimated mortality from asbestos- VI–4 are not strictly linear in dose.68

TABLE VI–4.—ESTIMATED ASBESTOS-RELATED CANCER MORTALITY PER 100,000 BY NUMBER OF YEARS EXPOSED AND EXPOSURE LEVEL

Cancer Mortality per 100,000 Exposed Asbestos fiber concentration (fiber/cc) Gastro- Lung Mesothelioma intestinal Total

1-year exposure

0.1 ...... 7.2 6.9 0.7 14.8 0.2 ...... 14.4 13.8 1.4 29.6 0.5 ...... 36.1 34.6 3.6 74.3 2.0 ...... 144 138 14.4 296.4 4.0 ...... 288 275 28.8 591.8 5.0 ...... 360 344 36.0 740.0 10.0 ...... 715 684 71.5 1,470.5

20-year exposure

0.1 ...... 139 73 13.9 225.9 0.2 ...... 278 146 27.8 451.8 0.5 ...... 692 362 69.2 1,123.2 2.0 ...... 2,713 1,408 271.3 4,392.3 4.0 ...... 5,278 2,706 527.8 8,511.8 5.0 ...... 6,509 3,317 650.9 10,476.9 10.0 ...... 12,177 6,024 1,217.7 13,996.7

45-year exposure

0.1 ...... 231 82 23.1 336.1 0.2 ...... 460 164 46.0 670.0 0.5 ...... 1,143 407 114.3 1,664.3 2.0 ...... 4,416 1,554 441.6 6,411.6 4.0 ...... 8,441 2,924 844.1 12,209.1 5.0 ...... 10,318 3,547 1,031.8 14,896.8 10.0 ...... 18,515 6,141 1,851.5 26,507.5

OSHA’s PEL for asbestos was 2 f/cc in 336.1 deaths (per 100,000 workers), percent (1,240 cases per 100,000 1983. Table VI–4 shows that after 45 which is the sum of deaths from 231 workers) at 0.5 f/cc. Using the linear years of exposure to asbestos at this lung cancers, 82 mesotheliomas, and model described above [RA = concentration, there would be an 23.1 gastrointestinal cancers. 0.055(f)(d)], the incidence of asbestosis estimated 6,411.6 deaths (per 100,000 As shown above in Table VI–3, there can also be calculated at a concentration workers). This is the sum of deaths from is also a significant reduction in the of 0.1 f/cc (not included by OSHA in 4,416 lung cancers, 1,554 incidence of asbestosis by lowering Table VI–4) following 45 years of mesotheliomas, and 441.6 exposures. For example, the lifetime exposure to asbestos. This yields 0.25 gastrointestinal cancers. By lowering its incidence of asbestosis would be percent, or 250 cases per 100,000 PEL to 0.1 f/cc, OSHA decreased the reduced from 4.97 percent (4,970 cases workers. Thus, by lowering the 8-hour risk of cancer mortality to an estimated per 100,000 workers) at 2 f/cc to 1.24 TWA PEL from 2 f/cc to 0.1 f/cc, we

68 Nicholson, p. 53, 1983.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00021 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 43970 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

would reduce the lifetime asbestosis practical lower limit of feasibility for than the slopes for the studies included risk from 4,970 cases to 250 cases per measuring asbestos levels reliably. in its risk assessment (51 FR 22632 and 100,000 exposed miners. D. Applicability of OSHA’s Risk 22637). This difference in slopes may Based on these reductions in cancer Assessment to the Mining Industry suggest that the risk of asbestos-related deaths and asbestosis cases, OSHA cancers is lower in miners and millers. demonstrated that a lowering of the PEL In its asbestos emergency temporary Because there is remaining significant below 2 f/cc would ‘‘substantially standard, and in its proposed, amended, risk of asbestos-related cancer at the reduce that risk’’ (51 FR 22612). OSHA and final asbestos rules (1983, 1984, OSHA PEL of 0.1 f/cc, we may be also noted— 1986, 1992, 1994), OSHA discussed few accepting a higher estimate of risk by mining and milling studies and Evidence in the record ‘‘has shown that relying on OSHA’s quantitative risk employees exposed at the revised standards’’ excluded these data in their risk assessment that excluded mining and PEL of 0.2 fiber/cc [OSHA’s 1986 standard] assessment. OSHA (51 FR 22637) stated, milling studies. remain at significant risk of incurring a The distinct nature of mining-milling data Although we are relying on OSHA’s chronic exposure-related disease, but (and hence the estimate of KL from these considerations of feasibility have constrained data) has been considered earlier. There is risk assessment, we also reviewed the OSHA to set the revised PEL at the 0.2 fiber/ some evidence that risks in the asbestos scientific literature to identify studies cc level. mining-milling operations are lower than that involved the exposure of miners When OSHA further reduced its PEL other industrial operations due to differences and millers to asbestos. Most of these from 0.2 to 0.1 f/cc in 1994, this in fiber size. ‘‘Thus, in determining the KL studies were conducted in Canada, statement was still true and the PEL for the final rule, the data from mining and although some have been conducted in continued to reflect technical feasibility milling processes were not considered. Australia, India, Italy, South Africa, and issues. OSHA stated (59 FR 40967)— OSHA suggested that the the United States. Table VI–5 lists some The 0.1 f/cc level leaves a remaining proportionality constants (i.e., KL, KM), of these mining and milling studies, in significant risk. However as discussed below also known as the slopes of the chronological order, and gives the [in OSHA’s 1994 Final Rule] and in earlier respective dose response curves, from salient features of each study. These documents, OSHA believes that this is the mining and milling studies are lower studies are in the rulemaking docket.

TABLE VI–5.—SELECTED STUDIES INVOLVING MINERS EXPOSED TO ASBESTOS

Author(s), year of publication Study group, type of asbestos Major finding(s) or conclusion(s)

Rossiter et al., 1972 ...... Canadian miners and millers, Chrysotile ...... Radiographic changes (opacities) related to age and exposure. Becklake, 1979 ...... Canadian miners and millers, Chrysotile ...... Weak relationship between exposure and dis- ease. Gibbs and du Toit, 1979 ...... Canadian and South African miners, Need for workplace epidemiologic surveillance Chrysotile. and environmental programs. Irwig et al., 1979 ...... South African miners, Amosite and crocidolite Parenchymal radiographic abnormalities pre- ventable by reduced exposure. McDonald and Liddell, 1979 ...... Canadian miners and millers, Chrysotile ...... Lower risk of mesotheliomas and lung cancer from chrysotile than crocidolite. Nicholson et al., 1979 ...... Canadian miners and millers, Chrysotile ...... Miners and millers: At lower risk of mesotheliomas, at risk of asbestosis (as factory workers and insulators), at risk of lung cancer (as factory workers). Rubino et al., Ann NY Ac Sci 1979 ...... Italian miners, Chrysotile ...... Role of individual susceptibility in appearance and progression of asbestosis. Rubino et al., Br J Ind Med 1979 ...... Italian miners, Chrysotile ...... Elevated risk of lung cancer. Solomon et al., 1979 ...... South African miners, Amosite and Crocidolite Sign of exposure to asbestos: Thickened interlobar fissures. McDonald et al., 1980 ...... Canadian miners and millers, Chrysotile ...... No statistically significant increases in SMRs. McDonald et al., 1986 ...... U.S. miners, Tremolite ...... A. Increased risk of mortality from respiratory cancer. McDonald et al., 1980 ...... U.S. miners, Tremolite ...... B. Increased prevalence of small opacities by retirement age. Cookson et al., 1986 ...... Australian miners and millers, Crocidolite ...... No threshold dose for development of radio- graphic abnormality. Amandus et al., 1987 ...... U.S. miners, and millers, Tremolite-Actinolite Part I: Increased prevalence of radiographic abnormalities associated with past expo- sure. Amandus and Wheeler, 1987 ...... U.S. miners, and millers, Tremolite-Actinolite Part II: Increased mortality from nonmalignant respiratory disease and lung cancer. Amandus et al., 1987 ...... U.S. miners, and millers, Tremolite-Actinolite Part III: Exposures below 1 f/cc after 1977, up to 100–200X higher in 1960’s and 1970’s. Armstrong et al., 1988 ...... Australian miners and millers, Crocidolite ...... Increased mortality from mesotheliomas and lung cancer. Enarson et al., 1988 ...... Canadian miners, Chrysotile ...... Increased cough, breathlessness, abnormal lung volume and capacity. McDonald et al., 1988 ...... U.S. miners, and millers, Tremolite ...... Low exposure and no statistically significant SMRs. McDonald et al., 1993 ...... Canadian miners and millers, Chrysotile ...... Increased SMRs for lung cancer and mesotheliomas as cohort aged.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00022 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43971

TABLE VI–5.—SELECTED STUDIES INVOLVING MINERS EXPOSED TO ASBESTOS—Continued

Author(s), year of publication Study group, type of asbestos Major finding(s) or conclusion(s)

Dave et al., 1996 ...... Indian miners and millers, Chrysotile ...... Higher exposures in surface than under- ground mines; higher exposures in mills than mines; restrictive lung impairment and radiologic parenchymal changes more com- mon in millers. McDonald et al., 1997 ...... Canadian miners and millers, Chrysotile ...... Risk of mesotheliomas related to geography and mineralogy of region; mesotheliomas caused by amphiboles. Nayebzadeh et al., 2001 ...... Canadian miners and millers, Chrysotile ...... Respiratory disease related to regional dif- ferences in fiber concentration and not di- mension. Ramanathan and Subramanian, 2001...... Indian miners and millers, Chrysotile and Increased risk of cancer, restrictive lung dis- tremolite. ease, radiologic changes, and breathing dif- ficulties; more common in milling.

These studies of miners and millers When OSHA lowered its PEL for Furthermore, section 101(a)(6)(A) of provide further evidence of potential asbestos from 2 to 0.2 f/cc (1986), and the Mine Act requires MSHA to set adverse health effects from asbestos then to 0.1 f/cc (1994), they used this health or safety standards— exposure. MSHA found that many of the definition of a ‘‘significant health risk’’ * * * on the basis of the best available observations presented in these studies and made the two findings as outlined evidence that no miner shall suffer material (e.g., age of first exposure, latency, in the Benzene Case. With respect to the impairment of health or functional capacity radiologic changes) are consistent with first finding, OSHA estimated the excess even if such miner has regular exposure to those from studies of factory and lifetime cancer risk to be 3.4 deaths per the hazards * * * for the period of his insulation workers. The exposure to 1,000 workers exposed to asbestos at 0.1 working lifetime. asbestos, a known human carcinogen, f/cc for a working lifetime. OSHA stated A significant health risk exists for results in similar disease endpoints (51 FR 22646), miners exposed to asbestos at our regardless of the occupation that has The finding that a significant risk exists is existing 8-hour full-shift exposure limit been studied. supported by OSHA’s quantitative risk of 2 f/cc. Miners, like the insulation E. Significance of Risk assessment, which is based upon studies of workers in the studies cited by OSHA, asbestos-exposed worker populations. are at risk of developing lung cancer, 1. Defining ‘‘Significant’’ Risk: The mesotheliomas, and asbestosis. These Benzene Case With respect to the second finding, effects are significant and clearly OSHA went on to say (51 FR 22647), We (MSHA) believe that this constitute a material impairment of proposed rule for asbestos meets the In accordance with the second element health and functional capacity. They requirements set forth by the OSHA [finding, sic] of the Supreme Court’s Benzene also emphasize the need for us to lower Benzene Case described below. We have decision on the determination of significant our PEL. By lowering the 8-hour full- relied on OSHA’s risk assessment, the risk, OSHA has determined that reducing the shift exposure limit to 0.1 f/cc, we studies used by OSHA in its permissible exposure limit for asbestos [from would significantly reduce the risk of development, and our review of more 2 f/cc, sic] to 0.2 f/cc is reasonably necessary asbestos-related lung cancers, to reduce the cancer mortality risk from recent studies and mining studies, mesotheliomas, and asbestosis. exposure to asbestos. * * * significant risks which further support OSHA’s findings. of asbestos-related cancer mortality and 3. Using the Experience of OSHA and In the Benzene Case, Industrial Union asbestosis are not eliminated at the exposure Current Studies to Demonstrate Department, AFL–CIO v. American level that is permitted under the new Significant Risk Petroleum Institute et al. (448 U.S. 607, standard [0.2 f/cc, sic]; however, the Under the Mine Act, section 1980), the U.S. Supreme Court ruled reduction in the risk of asbestos-related death 101(a)(6)(A), MSHA must base its health that, prior to the issuance of a new or and disease brought about by promulgation revised standard regulating of the new standard is both significant and and safety standards on— occupational exposures to toxic dramatic. * * * the latest available scientific data in materials, such as asbestos, OSHA is the field, the feasibility of the standards, and required to make two findings: OSHA concluded that the lowering of experience gained under this and other • They must determine that a their PEL from 0.2 to 0.1 f/cc would health and safety laws. ‘‘significant’’ health risk exists, and ‘‘further reduce a significant health In our proposed rule for asbestos, we • They must demonstrate that the risk’’ (59 FR 40966–40967). have relied heavily on the experience of new standard will reduce or eliminate 2. Demonstrating Significant Health OSHA, which demonstrates the that risk. Risk for the Miner feasibility of a 0.1 f/cc exposure limit for In the preamble to its 1994 final asbestos. We believe that this limit is asbestos rule (59 FR 40966, 1994), The Federal Mine Safety and Health technically and economically feasible OSHA provided an interpretation of a Act of 1977 (Mine Act), Title I, section for the mining industry. (See section ‘‘significant health risk’’. They stated, 101(a), requires MSHA VIII.B. Feasibility.) We also have OSHA has always considered that a * * * to develop, promulgate, and revise obtained and reviewed the latest working lifetime risk of death of over 1 per as may be appropriate, improved mandatory available scientific data on the health 1000 from occupational causes is significant. health or safety standards for the protection effects of asbestos exposure. MSHA This has been consistently upheld by the of life and prevention of injuries in coal or concludes that these studies provide courts. other mines. further support of the significant risk of

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00023 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 43972 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

adverse health effects following section II.B of this preamble and in the • Conform the asbestos standards for exposure to asbestos. existing regulatory language, asbestos is metal and nonmetal mines, surface coal Using OSHA’s risk assessment, we not a definitive mineral name, but rather mines, and the surface work areas of have demonstrated that a lowering of a commercial name for a group of underground coal mines by using the our 8-hour full-shift exposure limit from minerals with specific characteristics. same structure and wording in the rule 2 to 0.1 f/cc would significantly reduce Our existing standards clearly state that, text. For example, we retain the the risk of asbestos-related disease in ‘‘when crushed or processed, [asbestos] descriptive language ‘‘Asbestos is a miners. MSHA believes that other separate[s] into flexible fibers made up generic term for a number of hydrated existing standards help reduce the of fibrils’’ [§§ 56/57.5001(b)]; and ‘‘does silicates that, when crushed or remaining significant risk at this new not include nonfibrous or processed, separate into flexible fibers 0.1 f/cc PEL. For example, MSHA nonasbestiform minerals’’ (§ 71.702). made up of fibrils’’ from the metal and requires the use of engineering and Although there are many asbestiform nonmetal standards rather than the work practice controls to reduce a minerals, the term ‘‘asbestos’’ in our comparable language from the coal miner’s exposure to the PEL and, until existing standards is limited to the standards. We believe that this this concentration is reached, the use of following six (Federal Six): 71 descriptive language assists mine an approved respirator. MSHA also • Chrysotile (serpentine asbestos, operators in understanding the scope of requires the use of personal protective white asbestos); the standard. clothing and equipment, as necessary, • Amosite (cummingtonite-grunerite MSHA’s ANPRM did not specifically for equipment repair and for asbestos, brown asbestos); solicit information about which construction or demolition activities 69 • Crocidolite (riebeckite asbestos, asbestiform minerals we should and hazard communication and task blue asbestos); regulate. Even so, some commenters • training.70 As long as miners are likely Anthophylite asbestos (asbestiform suggested that MSHA should expand its to encounter asbestos, miners and mine anthophyllite); definition of asbestos to include other • operators will need to follow adequate Tremolite asbestos (asbestiform asbestiform minerals, so long as our safety procedures to ensure a reduction tremolite); and • analytical method excluded the of exposures. We anticipate risk Actinolite asbestos (asbestiform counting of cleavage fragments. One reduction to occur by the use of actinolite). commenter recommended that the PEL engineering controls and accepted Substantive changes to the definition be reduced not only for the six currently industrial hygiene administrative of asbestos are beyond the scope of this regulated asbestos minerals, but also for controls that effectively avoid disturbing proposed rule. We recognize that there other amphibole minerals in their asbestos on mine property. are limitations in the general analytical asbestiform habit. NIOSH commented methods, such as PCM and TEM, used that cleavage fragments of the VII. Section-by-Section Discussion of to identify and quantify the Federal Six. Proposed Rule serpentine minerals antigorite and Without the use of more complicated lizardite and amphibole minerals In the ANPRM, we asked commenters and costly analyses, it may not always contained in the series cummingtonite- for supporting information to help us be possible to differentiate other grunerite, tremolite-ferro-actinolite, and evaluate whether or not to— chemically similar amphiboles from the glaucophane-riebeckite should be • Lower our asbestos PEL, Federal Six. Also, the International • counted as asbestos if they meet the Revise our analytical methods and Minerals Association has proposed counting requirements for a fiber (3:1 criteria to make them more appropriate more specific nomenclature in the aspect ratio and greater than 5 µm in for the mining industry, and literature to classify some of the length). Another commenter asked that • Implement safeguards to limit take- 72 amphiboles. We decline to adopt such MSHA not include nonasbestiform home exposures. classifications here, because they are fibrous minerals and mineral cleavage We received almost 100 comments, beyond the scope of this proposed rule, fragments when we perform considered the commenters’ concerns, and propose to continue to use the microscopic analysis of samples. and discussed them in the following existing regulatory designations. Most commenters did not want sections. However, we are proposing a few MSHA to make changes to the fibers To make the standard easier to read, nonsubstantive changes to the existing regulated as asbestos in the existing we have divided the requirements in the regulatory language to clarify the standards. Specifically, they do not proposed standards into three standard. These wording changes would want us to address other asbestiform paragraphs: Definitions, Permissible have no impact on the minerals that we amphiboles found in mineral deposits Exposure Limits (PELs), and regulate as asbestos from that contained because they may not pose the same Measurement of Airborne Fiber in the existing standards. This proposed health problems that asbestos does. Concentration. For §§ 56/57.5001(b), the rule would— Some said that it would be unreasonable metal and nonmetal asbestos standards, • Clarify the term ‘‘amosite,’’ a name and expensive to try to meet exposure we numbered the paragraphs (b)(1), tied to asbestos from a specific limits for all these minerals. Other (b)(2), and (b)(3). For § 71.702, the coal geographical region, by adding the commenters at MSHA’s public hearing asbestos standard, we assigned the mineralogical term ‘‘cummingtonite- in New York (2002) stated that, paragraphs letters (a), (b), and (c). grunerite asbestos’’ parenthetically. • Add a definition for fiber to be more whatever they are called, these minerals A. Sections 56/57.5001(b)(1) and cause illness. 71.702(a): Definitions consistent with OSHA. This change would clarify that the dimensional At this time, we decline to propose Our existing definition of asbestos is criteria in our existing standards refer to substantive changes to the definition of consistent with several Federal the asbestiform habit of the listed asbestos as suggested by some agencies’ regulatory provisions, minerals. commenters. These changes are beyond including OSHA’s. As discussed in the scope of this rulemaking. We will 71 ATSDR, p.136, 2001; NIOSH Pocket Guide, continue to monitor the toxicological, 69 30 CFR 56/57.5005, 56/57.15006, and 71.701 2003. epidemiological, and mineralogical 70 30 CFR parts 46, 47, and 48. 72 Leake et al., 1997. research studies and other new

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00024 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43973

information relevant to protecting the 1. Sections 56/57.5001(b)(2)(i) and lower concentration over a longer time health of miners. 71.702(b)(1): 8-Hour Time-Weighted period. An excursion limit sets Average (TWA), Full-Shift Exposure boundaries for peak episodes of B. Sections 56/57.5001(b)(2) and Limit exposure that are not based on 71.702(b): Permissible Exposure Limits toxicological data. We are proposing an (PELs) Our sampling results indicate that excursion limit for asbestos to help MSHA currently limits a miner’s 8- there is not widespread overexposure to asbestos in the mining industry. maintain the average airborne hour TWA, full-shift exposure to 2.0 f/ concentration below the full-shift cc over a full shift; and limits a miner’s Recognizing this low exposure, many industry commenters generally exposure limit. For example, the 8-hour, short-term exposure to 10 f/cc over a 15- TWA airborne asbestos concentration minute sampling period for metal and supported reducing the PEL for asbestos to the OSHA level of 0.1 f/cc, if MSHA would be 0.06 f/cc for miners exposed nonmetal miners and 10 f/cc for a total to one 30-minute excursion per day at of one hour in an 8-hour day for miners also ensured that the analytical method only counted asbestos fibers. Labor 1.0 f/cc and 0.13 f/cc for miners exposed at surface work areas of coal mines. We to two 30-minute excursions per day at are proposing to adopt OSHA’s 8-hour representatives supported reducing the PEL for asbestos to the OSHA level of 1.0 f/cc. TWA, full-shift exposure limit of 0.1 f/ In the ANPRM, we requested 0.1 f/cc and recommended that MSHA cc and their 30-minute excursion limit comments on an appropriate level for a propose additional requirements from of 1.0 f/cc for the mining industry. short-term exposure limit (67 FR 15134). the OSHA asbestos standard. These actions would reduce by almost We specifically asked whether adopting Even though there was general 20-fold the risk of asbestos-related the OSHA limit of 1 f/cc over 30 agreement among the commenters to the deaths from a lifetime exposure at minutes would afford sufficient ANPRM that MSHA should adopt MSHA’s existing permissible exposure protection to miners in light of the OSHA’s asbestos exposure limits, some limits. The proposed exposure limits, health risk and the technical and commenters from a community however, were based on feasibility and economic feasibility of such a limit. association expressed concern about would not completely eliminate the Commenters offered no objections to asbestos originating at a local mine. risk. We believe that the proposed adopting OSHA’s excursion limit for They seemed concerned not only with excursion limit would help reduce the airborne asbestos, and some agreed that the health of miners, but also with residual risk from long-term exposure at this level is appropriate. the 0.1 f/cc 8-hour TWA, full-shift exposures of people in relative a. OSHA’s Short-Term Exposure exposure limit. proximity to the mining operations. Limit. As noted by the OIG, the continued They believe that any level of airborne When OSHA issued its 1986 asbestos occurrence of asbestos-related diseases asbestos is unacceptable. standard, it decided not to issue an and deaths among miners emphasizes While we are concerned about the explicit short-term exposure limit the need to reduce asbestos exposures. spread of asbestos from mine sites into (STEL). OSHA stated the basis for its MSHA’s recent field sampling data the atmosphere, asbestos occurs decision (51 FR 22709) as follows. (2000 through 2003) show that 2 percent naturally in many types of soils and ore of the total number of MSHA’s samples bodies. Although comments concerning To summarize, OSHA is not promulgating exceed OSHA’s PEL of 0.1 f/cc based on the asbestos exposure of those living a short-term exposure limit for asbestos because toxicological and dose-response TEM analysis. This same data indicate close to a mining operation fall outside evidence fail to show that short-term that 10 percent of the samples exceed the scope of this rule, the proposed exposure to asbestos is associated with an OSHA’s PEL of 0.1 f/cc based on PCM. reduction in the permissible exposure independent or greater adverse health effect MSHA’s asbestos ANPRM requested limits may reduce environmental levels than is exposure to the corresponding 8-hour information to help us determine as well. TWA level; that is, there is no evidence that appropriate exposure limits for the We are proposing an 8-hour TWA, exposure to asbestos results in a ‘‘dose-rate’’ mining industry, considering the health full-shift exposure limit of 0.1 f/cc. This effect. This is reflected in OSHA’s risk risk and technological and economic limit would significantly reduce the risk models for lung cancer and mesothelioma, feasibility. We specifically asked what which associate health risk with cumulative of material impairment of health or dose. The decision not to promulgate a short- would be an appropriate agency action functional capacity for miners exposed term exposure limit for asbestos is consistent considering these levels, and if OSHA’s to asbestos. with OSHA’s recent policy decision asbestos exposure limits would afford 2. Sections 56/57.5001(b)(2)(ii) and described in the Supplemental Statement of sufficient protection to miners. Most Reasons for the Final Rule for Ethylene Oxide commenters supported our adoption of 71.702(b)(2): Excursion Limit (50 FR 64) in which OSHA established that OSHA’s exposure limits. As previously discussed, asbestos short-term exposure limits for toxic As discussed below in section VII.C of poses a long-term health risk to exposed substances are not warranted in the absence this preamble, we are proposing to workers. There are no toxicological data of health evidence demonstrating a dose-rate incorporate the generic elements of PCM identifying a ‘‘dose-rate’’ 73 health effect effect. analytical methods for asbestos from exposure to airborne OSHA’s decision not to issue a STEL exposure monitoring by referencing concentrations of asbestos. ‘‘Dose-rate’’ was challenged in Public Citizen Health Appendix A of OSHA’s asbestos effect means that a specific dose can Research Group v. OSHA (796 F.2d standard (29 CFR 1910.1001). Appendix cause different health problems 1505), 1986. The U.S. Court of Appeals A lists both NIOSH 7400 and OSHA ID depending on the length of exposure. for the District of Columbia held that the 160 as examples of analytical methods For example, asbestos does not seem to Occupational Safety and Health Act that meet the equivalency criteria in have a ‘‘dose-rate’’ effect because compels OSHA to adopt a short-term OSHA’s asbestos standard. The exposure to a high concentration over a limit, if the rulemaking record shows evaluation or inclusion of other short time period poses no greater risk that it would further reduce a significant protocols that deviate from the criteria of an adverse health effect than if the health risk and is feasible to implement, for counting fibers in our existing worker received the same dose at a regardless of whether the record standards is beyond the scope of this supports a ‘‘dose-rate’’ effect. rulemaking. 73 OSHA (51 FR 22709), 1986. Subsequently, OSHA found that

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00025 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 43974 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

compliance with a short-term limit TABLE VII–1.—RELATIONSHIP OF SAM- proposing to retain this requirement for would further reduce a significant PLING METHOD TO MEASUREMENT PCM analysis. The proposed rule would health risk remaining after complying OF ASBESTOS require fiber concentration to be with the 8-hour TWA, full-shift determined by PCM using a method exposure limit. OSHA also found that Lowest level statistically equivalent to the OSHA the lowest excursion level which is Flow rate Sampling reliably meas- Reference Method in OSHA’s asbestos ured (f/cc) standard (29 CFR 1910.1001, Appendix feasible both to measure and to achieve (Lpm) time using 25-mm primarily through engineering and work filters A). practice controls is 1 f/cc measured over The OIG recommended that we use 30 minutes. For these reasons, in 1988, 2.5 ...... 15 minutes .. 1.05 TEM for the initial analysis of samples 2.0 ...... 1.31 collected to evaluate a miner’s personal OSHA promulgated an asbestos 1.6 ...... 1.63 excursion limit of 1 f/cc over a sampling exposure to asbestos. In our 2002 1.0 ...... 2.61 asbestos ANPRM, we requested period of 30 minutes (53 FR 35610). 0.5 ...... 5.23 information to help us determine the b. Minimum Detectable Level and 2.5 ...... 30 minutes .. 0.51 2.0 ...... 0.65 benefits and feasibility of changing our Feasibility of Measuring Short-Term 1.6 ...... 0.82 asbestos analytical method from PCM to Excursions. 1.0 ...... 1.31 TEM for evaluating a miner’s exposure As discussed in OSHA’s 1986 0.5 ...... 2.61 to asbestos. For the reasons discussed in asbestos final rule (51 FR 22686), the this preamble, we cannot justify using a key factor in sampling precision is fiber We recognize that in some situations, TEM analytical method for the initial such as low background dust levels, loading. To determine whether the determination of compliance with our ower exposures could be measured; analytical method described in asbestos PELs. however, the risk of overloading the Appendix A of its asbestos standard filter with debris increases when using 1. Brief Description and Comparison of could be used to analyze short-term the higher flow rates. We can be Three Analytical Techniques samples, OSHA calculated the lowest confident that we are measuring the To ease understanding of the reliable limit of quantification using the actual airborne concentrations of discussion that follows, this section following formula: asbestos, within a standard sampling briefly describes the three analytical and analytical error (±25 percent), when C = [(f/[(n)(Af)])(Ac)]/[(V)(1,000)] techniques that MSHA has used for we use the minimum loading suggested analyzing asbestos samples. All three where: by the OSHA Reference Method (29 CFR techniques involve counting fibers. C is fiber concentration (in f/cc of air); 1910.1001, Appendix A). The excursion MSHA has used— limit of 1.0 f/cc for 30 minutes is the • f is the total fiber count; Phase contrast microscopy (PCM) lowest concentration that we can on air samples to determine a miner’s n is the number of microscope fields measure reliably for determining exposure for comparison with our examined; compliance with the excursion limit. permissible exposure limits (PELs) for 2 Some commenters supported MSHA’s Af is the field area (0.00785 mm ) for a asbestos. adoption of OSHA’s asbestos excursion properly calibrated Walton-Beckett • limit of 1.0 f/cc for 30-minutes. Many Transmission electron microscopy graticule; other commenters offered no objections, (TEM) on the same air samples analyzed Ac is the effective area of the filter (in choosing to remain silent on this issue. by PCM when we need to confirm the mm2); and We have considered the comments and presence of asbestos and distinguish are proposing an asbestos excursion asbestos from other fibers in the sample. V is the sample volume (liters). • limit of 1.0 f/cc over a minimum Polarized light microscopy (PLM) Table VII–1 was generated from the sampling time of 30 minutes. to analyze bulk samples collected from above equation. The table shows that 1.0 an area suspected of having asbestos in f/cc measured over 30 minutes can be C. §§ 56/57.5001(b)(3) and 71.702(c): the ore or dust, not for air samples Measurement of Airborne Fiber reliably measured when pumps are used collected to determine a miner’s Concentrations at the higher flow rates of 1.6 Lpm or exposure. more, using the 25-mm filters. We currently require asbestos samples Table VII–2 below presents a brief to be analyzed by PCM for the initial summary of various features of these determination of exposure and three analytical techniques. The values compliance with the PELs. We are listed are approximate.

TABLE VII–2.—MSHA’S COMPARISON OF THREE ANALYTICAL TECHNIQUES 74 USED TO ANALYZE ASBESTOS SAMPLES

Criteria PCM TEM PLM

Magnification ...... Up to 1,000X; typically 400–450X Up to 1,000,000X; typically Up to 1,000X; typically 10–45X. 10,000X. Resolution ...... 0.2 µm ...... 0.001 µm 75 ...... 0.2 µm. Sample Area Examined ...... Minimum: 100 fibers & 20 fields; 100 fibers or 4.4 mm2 minimum Scan entire prepared sample (1 or 100 fields (0.157–0.785 (0.06–0.4 mm2)*. cm2). mm2). Additional information...... None ...... Crystal structure & elemental Refractive index. composition. Microscope cost ...... $1,500–$2,000 ...... $200,000–$300,000 ...... $1,500–$2,000. Analysis cost/filter ...... $10–$15 ...... $100–$400 ...... $10–$15. Analysis time/filter ...... 0.25–0.5 hour ...... 3–4 hours or more ...... 0.25–0.5 hour.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00026 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43975

TABLE VII–2.—MSHA’S COMPARISON OF THREE ANALYTICAL TECHNIQUES 74 USED TO ANALYZE ASBESTOS SAMPLES— Continued

Criteria PCM TEM PLM

Degree of expertise of analysts ..... Requires a moderate level of ex- Requires a high level of expertise Requires a moderate level of ex- pertise; 40 hours training min- and experience. pertise; 40 hours training min- imum. imum. * NIOSH 7402 depends on loading: light–40 fields; medium–40 fields or 100 fibers; heavy–6 fields and 100 fibers.

2. Fiber Identification Using The OIG recommended that MSHA and environment sampled.78 To set a Transmission Electron Microscopy use TEM for its initial analysis to meaningful permissible exposure limit (TEM) determine if an asbestos sample is over based on TEM analysis, we must have the PEL. MSHA believes that analyzing either— a. Advantages and Disadvantages of • TEM Analysis an airborne dust sample from a mine, Peer-reviewed epidemiology or The transmission electron microscope which might contain asbestos, requires toxicology studies relating TEM analysis additional expertise not readily and adverse health effects, or (TEM), equipped with an energy • dispersive x-ray spectrometer (EDS) and developed through experience analyzing A predictive relationship using selected area electron diffraction samples known to contain asbestos. We correlating TEM and PCM for samples (SAED) is generally capable of recognize that EPA routinely uses TEM collected in a mining environment. (ii) Level of Expertise. identifying the mineralogy of individual for the analysis of air samples collected for asbestos abatement under the One commenter representing an asbestos fibers. Even so, TEM does not industry association at MSHA’s public always have sufficient precision to make Asbestos Hazard Emergency Response Act (AHERA) and requires the use of hearing in Charlottesville, Virginia definitive distinctions between closely (2002) testified that TEM was not a related minerals, such as between TEM to characterize workers’ asbestos exposures (40 CFR part 763). MSHA method for routine monitoring. This winchite commenter also pointed out— 3∂ currently uses TEM on a limited basis, [(NaCa)Mg4(Al,Fe )Si8O22(OH)2] and tremolite [Ca Mg Si O (OH) ].76 when necessary, to verify the presence * * *that very few commercial TEM labs 2 5 8 22 2 are competent to perform valid analyses of Because electron microscopes provide of asbestos in samples. These samples often contain few fibers among much the complicated mineralogical mixtures that greater magnification and greater image you find in mining and quarrying operations. clarity, including sharper three- dust and a variety of other interferences. In the ANPRM, we requested dimensional images than light Another commenter at the comments on the use of TEM including microscopes, TEM can detect fibers that Charlottesville public hearing testified cost, availability, comparisons of PCM are undetectable using PCM. Routine that TEM is fallible. This commenter to TEM, and a possible relationship of use of TEM analysis, however, would said that electron diffraction patterns for TEM to a PEL. In response to the have some significant disadvantages. structurally similar minerals can be ANPRM, some commenters suggested • Epidemiological data correlating difficult to distinguish from one that MSHA use TEM to augment PCM TEM asbestos exposure levels with another. Each particle in the sample measurements. Overall, industry asbestos-related diseases is not available may be of a different composition and commenters did not recommend the use for conducting a new risk assessment. the analyst cannot assume that every • TEM analysis is time consuming of TEM for the initial analysis of fiber particle with the same shape is the same and expensive, requiring highly skilled samples for comparison to the PELs. mineral. personnel for instrument operation and Commenters did not dispute additional, (iii) High Cost of TEM Analysis. confirmatory analysis of samples that data interpretation, especially when Several commenters representing an show possible exposure to asbestos in applied as the primary analytical industry association each commented excess of the PELs. NIOSH also did not method. on the high cost of TEM analysis. One • Few facilities offer TEM analysis for believe that TEM should be used for commenter stated that, because the asbestos air samples collected in a routine monitoring even though they variability of the measurement increases mining environment. consider TEM a valuable tool in mineral at the lower concentrations, when the Another disadvantage of TEM is that identification. NIOSH comments stated PEL is lowered it is important to it uses an even smaller amount of the reasons for not using TEM as the increase the frequency of monitoring sample than is used in PLM or PCM primary method for determining and, therefore, the cost of sample analysis. Asbestos fibers may not be compliance with the PELs as (i) the lack analysis becomes an issue. of health risk data associated with TEM, present in the small portion of sample 3. Phase Contrast Microscopy (PCM) for (ii) the level of expertise required, and examined under the electron the Analysis of Personal Exposure (iii) the high cost. microscope, even when it is present in Samples the larger sample examined by PLM or (i) Lack of Health Risk Data Based on The use of PCM for quantitative PCM. Despite its disadvantages, TEM TEM. OSHA did not use analytical results analysis of samples does not allows us to better identify asbestos based on TEM in its original risk differentiate between mineral species. minerals in air samples collected in a assessment for asbestos. Although There is industry concern that mine. 77 b. Use of TEM to Determine attempts have been made, researchers misidentification of fibers as asbestos Compliance with MSHA’s PELs. have not reported a strong, consistent can lead to incorrect conclusions, correlation between PCM and TEM resulting in unnecessary expenses for 74 MSHA’s summary of its literature reviews and analyses. The relationships that are mining companies. PCM counting experience. reported are specific to the fiber type schemes address the key problem of 75 Clark, p. 5, 1977. 76 Leake et al., 1997. 77 Snyder et al., 1987. 78 Verma and Clark, 1995.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00027 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 43976 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

needing to make a relatively fast, cost- the smaller fibers should not be consistency issues.86 Commenters to our effective evaluation of a situation in a excluded.83 asbestos ANPRM suggested that we mine so as to protect miners from In recommending an asbestos consider thoracic sampling to minimize danger to their health. PCM maintains standard in 1972, NIOSH suggested interference from large particles. the integrity, meaning, and usefulness of using the same size criteria that the Testimony at MSHA’s public hearing in the analytical method for evaluating British adopted. They also Charlottesville (2002) presented a samples relative to the historic health recommended reevaluating these counting technique based on the typical data.79 criteria when more definitive characteristics of asbestos in air. a. Discussion of Microscope information on the biologic response Another commenter stated that several Properties. and precise epidemiologic data were approaches have been tried to remove One issue commenters mentioned developed. When exposure data were non-asbestos minerals from samples, repeatedly concerning PCM is the not obtained using PCM, NIOSH applied such as low temperature ashing or limited resolution and magnification of a conversion factor to the non-PCM data dissolution, but they would not be light microscopes compared to electron to estimate PCM concentrations for use useful for mining samples. Another microscopes. as the basis of a recommended commenter suggested using a higher (i) Resolution. permissible occupational exposure aspect ratio to increase the probability The resolution of the microscope is level. that the structures counted are fibers. the smallest separation between two A number of commenters testified Several commenters suggested the objects that will allow them to be (Charlottesville, 2002) that PCM development of a new analytical distinctly visible. The higher the methodology includes more than method. resolving power of a microscope, the asbestos when determining fiber Overall, commenters recognized that smaller the distance can be between two concentration in air. The commenters it takes far less time to develop expertise particles and have them still appear as suggested that the lower risk seen in in counting fibers using PCM than in two distinct particles. Resolution is epidemiological studies relating PCM to developing expertise using TEM. NIOSH about 0.22 µm using PCM and 0.00025 adverse health outcomes in miners was has developed a 40-hour training course µm using TEM. This means that where possibly due to the background material for teaching analysts to count asbestos the analyst sees a single fiber using inherent in air samples taken in a fibers. PCM, that same analyst might see a mining environment. They speculated The availability of analyst training number of thinner fibers using TEM. that the background material had been courses, and the formation of (ii) Magnification. counted and included in the estimated accreditation bodies requiring The level of magnification is another asbestos concentrations. This may have laboratory quality assurance programs, PCM microscopy issue. Magnification is overestimated exposures and resulted in helps minimize the variations in the ratio of the size that the object a dilution of the dose-response measurements between and within appears under the microscope to its relationship presented in scientific laboratories. Accreditation bodies actual size. PCM analytical methods publications. require laboratories to use standardized specify a magnification of 400 to 450 c. Subjectivity and Consistency of analytical methods. AIHA also has the times (×) the object’s actual size. The Counting Asbestos Fibers Asbestos Analyst Registry that specifies magnification using TEM can be The fiber count obtained using the criteria for competence, education, and 10,000X to 1,000,000X. This means that PCM method is dependent on several performance for analysts. In addition to the analyst sees a smaller amount of the factors. These factors include the these programs, our incorporation of sample using TEM than when using analyst’s interpretation of the counting OSHA’s Appendix A would help PCM. rules, the analyst’s visual acuity, the minimize the subjectivity and increase b. Health Risk Data Based on PCM. optical performance of the microscope, consistency of measuring airborne Historically, asbestos samples have and the optical properties of the asbestos concentrations by specifying been analyzed by mass (weighing), prepared sample.84 Much of the core elements of acceptable analytical counting (microscopy), or a qualitative variability is attributed to the ability of PCM methods. property (spectroscopy). When the analyst to observe and size fibers. 4. MSHA’s Incorporation of OSHA’s recommending an exposure standard for The American Industrial Hygiene Appendix A chrysotile asbestos, the British Association (AIHA) Proficiency Occupational Hygiene Society Analytical Testing Program (PAT), Commenters generally supported the contended 80 that the microscopic operated in cooperation with NIOSH, use of PCM for the initial analysis of counting of particles greater than 5 µm maintains a database for historical data fiber samples for determining in length would show a relationship relating to asbestos fiber counting using compliance with the PELs. Commenters’ with the prevalence of asbestosis similar PCM. This program, begun in 1972, major concerns focused on fiber to those based on the mass of respirable provides statistical evaluation of counting procedures. Commenters asbestos. Many scientific papers have laboratory performance on test samples. suggested that differential counting suggested that counting only fibers At its inception in 1968, the method techniques be developed to analyze air longer than 5 µm would minimize used by laboratories participating in this samples for asbestos using PCM and variations between microscopic program was the U.S. Public Health taking into consideration the fiber techniques 81 and improve the precision Service method (USPHS 68).85 The morphology and the distributions or of the results.82 Nonetheless, this counting rules for this method were populations of distinct fiber groups with criterion was accepted as an index of vague and required little microscope characteristic dimensions. Other exposure, even though some believed standardization. commenters stated that particle that, due to their possible health effects, Work has been done to modify the characteristics could not reliably be PCM method to address these used to differentiate fibers from cleavage 79 Wylie et al., 1985. fragments when examining relatively 80 Lane et al., 1968. 83 ACGIH–AIHA, 1975; NIOSH, 1972. small numbers of fibers. 81 ACGIH–AIHA, 1975. 84 Rooker et al., 1982. 82 Wylie, 2000. 85 Schlecht and Shulman, 1995. 86 Pang, 2000; Harper and Bartolucci, 2003.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00028 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43977

In this rulemaking, we propose to they relate to the processing of samples current field sampling methods are continue to use PCM to determine collected in a mining environment. For adequate for most mines and quarries, asbestos concentrations. PCM was used example, the ASTM dilution method (D particularly when no significant amount in the development of past exposure 5755–95) for overloaded samples has of asbestos is found. They also assessments and risk estimates and is allowed laboratories to recover useable suggested that respirable dust sampling relatively quick and cost-effective. Thus, results from airborne exposure samples using a cyclone might be a means to with respect to analytical methods, this that, in the past, had been invalidated. remove interfering dust from the proposed rule is not substantively We note that both ASTM and the sample. NIOSH suggested that we could different than our existing standards. National Stone Sand and Gravel use thoracic samplers, but that studies We also have added language to allow Association are pursuing the performed on their use did not include for our acceptance of other asbestos development of an analytical method for mines and further positive test results analytical methods that are at least as asbestos in mining samples. We would would be needed before they could effective in identifying potential consider analytical methods that afford promote their use in mining. overexposures. a better measurement alternative as they We believe that our current sampling The OSHA Reference Method, become available. We believe that procedures are adequate and we are mandatory Appendix A to the OSHA allowing statistically equivalent proposing to continue using them. Our asbestos standard (29 CFR 1910.1001), analytical methods would remove current procedures, which we updated specifies the elements of an acceptable barriers to innovation and technological in 2000, specify using several, typically analytical method for asbestos and the advancement. three, 25-mm filter-cassettes in series to quality control procedures that We specifically request information collect a full-shift sample. Depending on laboratories performing the analysis on additional criteria for equivalency for the amount of visible dust in the air, must implement. Paragraph (d)(6)(iii) of use in evaluating alternative analytical these procedures allow the setting of OSHA’s asbestos standard (29 CFR methods for the determination of pump flow rates to optimize fiber 1910.1001) requires employers, who asbestos in air samples collected in a loading and minimize or eliminate must monitor for asbestos exposure, to mining environment. We also request mixed dust overload. We are not use a method for collecting and information about analytical methods considering the use of a cyclone to analyzing samples that is equivalent to for which equivalency has already been capture respirable dust because research the OSHA Reference Method (ORM), demonstrated. indicates that larger durable fibers also could cause adverse health effects. and also describes the criteria for 5. MSHA Asbestos Control Program equivalency. For the purpose of this In the ANPRM, we asked whether or 6. Bulk Sample Analysis Using proposed rule, MSHA would consider a not our current sampling methods met Polarized Light Microscopy (PLM) method equivalent if it meets the the needs of the mining community and In the ANPRM, we asked what following criteria: how mineral dust interferences could be method was most appropriate for MSHA [from 29 CFR 1910.1001(d)(6)(iii)] removed from mining samples. The to use to analyze bulk samples for (A) Replicate exposure data used to ANPRM also asked for comments on asbestos in the mining industry. The establish equivalency are collected in side- other ways to reduce miners’ exposures, presence of asbestos in a bulk sample by-side field and laboratory comparisons; such as increased awareness of potential does not mean that it poses a hazard. and asbestos hazards at the mine site and the The asbestos must become airborne and (B) The comparison indicates that 90% of provision of adequate protection. We be respirable, or contaminate food or the samples collected in the range 0.5 to 2.0 times the permissible limit have an accuracy also asked for suggestions on what water, to pose a health hazard to miners. range of plus or minus 25 percent of the ORM educational and technical assistance The detection of asbestos in a bulk results at a 95% confidence level as MSHA could provide and what other sample serves to alert mine operators, demonstrated by a statistically valid protocol; factors, circumstances, or measures we miners, and MSHA to the possible and should consider when engineering presence of asbestos. One mining (C) The equivalent method is documented controls are unable to reduce asbestos association stated that air monitoring is and the results of the comparison testing are exposure below the PEL. not the preferred scheme to screen for maintained. We received some criticism possible asbestos exposure. They Appendix A of OSHA’s asbestos concerning our sampling and analysis believe, and we agree, that knowledge of standard lists NIOSH 7400 and OSHA procedures from a few commenters who the geology of asbestos and ID–160 as examples of analytical believed that we should develop identification of asbestos in bulk methods that meet these criteria. In specific test procedures for the sampling samples may be a useful step in addition, there are other PCM analytical and analysis of bulk samples for the determining whether asbestos is present methods for asbestos: mining environment, as well as specific in the ore or host rock. • The Asbestos International air sampling procedures (including We are not proposing to use bulk Association (AIA), AIA RTM1, pump flow rates, cassette types, and samples to determine asbestos ‘‘Airborne Asbestos Fiber filter matrix). They also believed that we exposures in mining. We are requesting Concentrations at Workplaces by Light should improve our reports by comments on whether MSHA’s use of Microscopy (Membrane Filter Method).’’ including inspection field notes, routine, periodic bulk sampling would • The International Organization for location, purpose, and procedure be useful in determining whether or not Standardization (ISO), ISO followed, as well as descriptions of the we should take personal exposure air 8672:1993(E), ‘‘Air quality— accuracy, meaning, and limitations of samples to evaluate miners’ exposures Determination of the number the results. In its comments to the to asbestos at mines suspected of having concentration of airborne inorganic ANPRM, one trade association naturally occurring asbestos. fibres by phase contrast microscopy— recommended that we maintain our MSHA also uses the detection of Membrane filter method.’’ current, established asbestos monitoring asbestos in bulk samples as a trigger for MSHA recognizes that there are protocols with emphasis on full-shift its compliance assistance activities. We advantages and disadvantages of various monitoring for comparison to the PEL. have trained MSHA inspectors on ways PCM analytical methods, especially as Another trade association stated that our to identify asbestos in the ore and

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00029 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 43978 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

surrounding rock formations at mines Mine operators are encouraged to protective measures, such as personal and to pass this information on to mine measure the potential for take-home protective equipment and showers operators. Analysis of samples of contamination and provide protective before leaving work, to prevent take- accumulated settled dust from a mill or measures where necessary to minimize home contamination. construction debris can identify areas or secondary take-home exposures. activities that would require special 3. MSHA’s Considerations in Making Its 1. MSHA’s Request for Information precautions. After considering the Decision To Use Non-Regulatory results of the bulk sample analysis, MSHA’s ANPRM for measuring and Methods To Address the Hazard From together with its strengths and controlling asbestos exposures at mines Take-Home Contamination weaknesses, the mine operator, miners, included requests for information and and MSHA can take appropriate action data to help us evaluate what we could In determining an appropriate to reduce the risk of exposure, which do to eliminate or minimize take-home proposed action for preventing take- would help reduce the risk of asbestos- contamination. We asked how and/or home contamination, we considered the related diseases among miners. should MSHA be addressing take-home comments to the ANPRM, OSHA’s and Analysis of bulk samples is usually contamination. We also asked about EPA’s requirements, and the performed using PLM. Commenters to provisions for the special needs of small recommendations of NIOSH and the the ANPRM expressed concern that the mine operators and what assistance OIG. We based our determination to PLM analysis may not detect asbestos (e.g., step-by-step instructions, model propose to address asbestos take-home when it is present. A particle must be programs, certification of private contamination through non-regulatory at least 0.5 µm in diameter to refract programs) we could provide. We also measures on the following factors: light and many asbestos fibers are too requested information on the types of • Existing standards requiring protective clothing miners currently use thin to refract light. Asbestos may be a engineering controls for airborne when working in areas where asbestos small percentage of the parent material contaminants, respiratory protection, or not uniformly dispersed in the may be present, and the types of personal protective clothing, hazard sample and, therefore, may not be seen preventive measures currently in use communication, and housekeeping, in the small portion of sample that is when miners leave the area, to prevent together with a lower PEL, would examined under the microscope. In the spread of asbestos exposure. provide sufficient enforcement authority addition, the method could detect 2. Commenters’ Responses to the Take- asbestos erroneously because a to assure that mine operators take Home Contamination Issue in MSHA’s adequate measures when necessary to nonasbestiform mineral could have a Asbestos ANPRM refractive index similar to one of the prevent asbestos take-home asbestos minerals. Another problem Commenters expressed concern that contamination. with identifying asbestos using PLM is we would apply the requirements in • There are no asbestos mines or that all varieties of a mineral show the OSHA’s and EPA’s standards to trace mills currently operating in this country same refractive index. For example, levels of fibrous mineral exposures at and different ore bodies of the same even an experienced analyst might not mines, pits, and quarries. Many industry commodity, such as vermiculite mining, differentiate between the asbestiform commenters urged MSHA to limit are not consistent in the presence, protective measures for take-home and nonasbestiform varieties of a amount, or dispersion of asbestiform contamination to those activities mineral based on their refractive minerals. Currently, asbestos exposures involving known asbestos and asbestos- indices. in mining are low. As discussed in Although a trained individual may be containing products, such as those section V.D.2 of this preamble, only two able to identify bulk asbestos by its regulated by OSHA and EPA. For of the 123 mines sampled for asbestos appearance and physical properties, the example, commenters suggested that identification can be more difficult MSHA adopt appropriate provisions in the ore show personal asbestos when the asbestos is dispersed in a dust from the OSHA asbestos standard for exposures exceeding 0.1 f/cc. This is sample or is present in low construction workers, for asbestos less than 2 percent of the sampled concentration in a rock. A commenter at abatement workers, and for those miners mines. MSHA’s hearing in Charlottesville whose exposures exceed MSHA’s PEL. • Some mines with asbestos minerals (2002) testified that none of the existing Commenters cautioned MSHA to be in the ore or host rock have methods for bulk sample analysis (EPA, mindful of the definitions of asbestos implemented protective measures NIOSH, ASTM) were designed for when analyzing samples to determine voluntarily. MSHA experience in the complex mine environments. compliance. They also urged MSHA to recent past indicates that mine operators acknowledge the presence of and mining companies are increasingly D. Discussion of Asbestos Take-Home interferences in mining samples, as well Contamination aware of asbestos hazards and have been as the differences between willing to cooperate with MSHA to This proposed rule does not include nonasbestiform amphiboles and their eliminate this hazard. standards to address asbestos take-home asbestos analogues. Some commenters • contamination. We recognize the cautioned that, unless MSHA The measures taken to prevent take- important role of take-home exposures constructed the provisions for reducing home contamination are varied, and in contributing to asbestos disease of take-home contamination carefully, the mine operators would have the freedom workers and their family members. We consequences for the mining industry to eliminate this hazard in a manner believe that a combination of might be costly with little or no benefit based on site-specific exposure enforcement and compliance assistance to miners. measurements and the nature of the activities, together with increased NIOSH encouraged MSHA to adopt asbestos exposures at the mine. For education and training of mine measures included in its 1995 Report to example, mine operators could inspectors, mine operators, and miners, Congress on their Workers’ Home minimize or prevent asbestos take-home coupled with the lowering of the PELs, Contamination Study Conducted under contamination by providing disposable would be effective in preventing the Workers’ Family Protection Act. coveralls or on-site shower facilities asbestos take-home contamination. Labor participants also supported coupled with clothing changes.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00030 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43979

4. MSHA’s Activities for Eliminating the § 71.702 (the asbestos standard for coal asbestos exposures. Additional deaths Risk of Asbestos Take-Home mines) in paragraphs (c) and (d) of would be avoided by decreasing miners’ Contamination § 71.701, which contain the exposures to short-term bursts of We believe that mine operators and requirements for controls and sampling. airborne asbestos undetectable by the miners would take action to eliminate The existing language in § 71.701(c) and proposed 8-hour TWA, full-shift (d) references the Threshold Limit exposure limit. We estimate that any possible recurrence of a disaster,  such as that in Libby, Montana, if they Values (TLVs ) and excursion limits in lowering the excursion limit from 10 f/ understand the hazards and ways to § 71.700, but not the asbestos exposure cc over 15 minutes to 1 f/cc over 30 minimize the risk. To that end, we are limits in § 71.702. MSHA regulations minutes would reduce the risk of death placing special emphasis on the currently require mine operators to from lung cancer, mesothelioma, or potential hazard from asbestos take- control miners’ exposures to airborne gastrointestinal cancer by 1 additional home contamination in our contaminants and to sample for airborne avoidable death for every 1,000 miners enforcement, compliance assistance, contaminants, as necessary, to exposed to asbestos at the proposed and educational activities as follows. determine when and where such PELs. controls may be needed. In developing a. Enforcement Activities. We are aware that lowering our PELs • Enforce the new, lower PELs when this proposed rule, we determined that § 71.701 was unclear as to its would not completely eliminate the risk they become effective. of asbestos-related material impairment • Continue enforcement of standards applicability to asbestos exposures. This proposed rule would clarify our intent of health or functional capacity. We applicable to providing special expect some additional risk reduction protective equipment and clothing that coal mine operators control miners’ exposures to asbestos. from mine operators’ management whenever environmental hazards are directives to avoid disturbing asbestos encountered in a manner capable of VIII. Regulatory Analyses on mine property. causing injury or impairment, e.g., § 56.15006. A. Executive Order (E.O.) 12866 b. Calculation of Deaths Avoided. • Ensure that mine operators provide In our ANPRM on asbestos exposure, The benefits resulting from the miners, who are at risk of being we specifically requested information, lowered PELs depend on several factors exposed, with information about the data, and comments on the costs and including— signs, symptoms, and risk for benefits of an asbestos rule, including • Existing and projected exposure developing asbestos-related illness as what engineering controls and personal levels, required by the hazard communication protective equipment are being used to • standard. protect miners from exposure to Age of the miner at first exposure, b. Compliance Assistance. asbestos and to prevent take-home • Number of workers exposed, and • Continue to monitor targeted mines contamination. Considering the public • Risk associated with each exposure for the presence of asbestos. comments, and MSHA data and level. • Encourage mine operators to experience, we assessed both the costs comply with OSHA’s asbestos standard, and benefits of this proposed rule in We estimate the number of miners or hire professionals skilled and accordance with Executive Order 12866. currently exposed and their level of certified in working with asbestos, when The following sections summarize the exposure from personal exposure they engage in construction, demolition, analysis of benefits and costs presented information gathered during our or renovation activities at the mine. in the Preliminary Regulatory Economic inspections between January 2000 and • Issue an updated Program Analysis (PREA) for this proposed rule. December 2003. These data are available Information Bulletin (PIB) on asbestos to The PREA contains a full disclosure of on our Web site at http:// include a greater emphasis on protective our methodology and the basis for our www.msha.gov. Section V of this measures to reduce take-home estimates. preamble contains the characterization contamination. We expect distribution and assessment of exposures in mining. 1. Discussion of Benefits this year. Laboratory results indicate that c. Educational Activities. The benefits of a rulemaking exposure concentrations are unevenly • Continue outreach to mine addressing measurement and control of distributed across mines and miners. operators through training courses, asbestos would be the reduction or We use four fiber concentration levels to informational materials, and topical elimination of diseases arising from estimate the risk to miners. The break local meetings. exposure to asbestos. Exposure to points for these exposure levels are the • Issue an updated Health Hazard airborne asbestos can cause the proposed and existing exposure limits. Information Card for miners this year to development of lung cancer, Observations show that 90 percent of increase miners’ awareness of the mesothelioma, gastrointestinal cancer, the sampling results are below 0.1 f/cc. hazards of take-home contamination and asbestosis. Other associated adverse from asbestos or other asbestiform health effects include cancers of the To estimate the expected number of minerals and to suggest measures that larynx, pharynx, and kidneys. A person asbestos-related deaths, we applied the miners can take to prevent it. with an asbestos-related disease suffers OSHA’s linear, no-threshold, dose- • Continue specialized asbestos material impairment of health or response risk assessment model to our hazard and sampling training for mine functional capacity. existing and proposed PELs. The upper inspectors. a. Summary of Benefits. exposure limit is 10 f/cc because the We estimate that between 1 and 19 range of information derived from the E. Section 71.701(c) and (d): Sampling; deaths could be avoided during the next epidemiological studies used to General Requirements [Controlling 65 years by lowering the 8-hour TWA, determine the dose-response Asbestos Exposures in Coal Mines] full-shift exposure limit from 2.0 f/cc to relationship in OSHA’s quantitative risk For surface coal mines and surface 0.1 f/cc. This equates to a reduction of assessment does not include higher worksites at underground coal mines, between 9 and 84 percent of levels. The expected reduction of deaths we are proposing to add a reference to occupationally related deaths caused by resulting from lowering the PELs would

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00031 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 43980 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

be the differences between the expected combine this supplemental information of an excursion limit from the difference deaths at each exposure level.87 with PCM information to calculate our in concentration between the 8-hour OSHA estimated cancer mortality for lower estimate of benefits. TWA, full-shift exposure limit (0.1 f/cc) workers exposed to asbestos and We estimate that there would be from and the excursion limit averaged over published these data in their 1986 final 0.5 to 13.1 lung cancer deaths avoided, the full shift [(1 f/cc)/(16 30-minute rule (51 FR 22644). We discuss OSHA’s 0.2 to 4.4 mesothelioma deaths avoided, periods) = 0.063 f/cc]. The lifetime risk asbestos risk assessment in section VI of and 0.1 to 1.3 gastrointestinal cancer associated with an exposure to 0.1 f/cc this preamble and have reproduced deaths avoided. The total number of from either of the three types of cancer OSHA’s mortality data in Table VI–4. cancer deaths avoided by this rule is 0.00336, if first exposed at age 25 and c. Benefit of the Proposed 0.1 f/cc 8- would be the sum of cancer deaths exposure continues every work day at hour TWA, Full-Shift Exposure Limit. avoided at all the mines included in the that level for a duration of 45 years. The The current deaths from lung cancer, exposure data, that is, the mines we risk associated with exposure to 0.063 mesotheliomas, gastrointestinal cancer, have sampled. Based on the best f/cc using the same age and duration of and asbestosis are the result of past available information, we expect a exposure is 0.00212. The difference in exposures to much higher air reduction of between 1 and 19 deaths lifetime risk is 0.00124. This risk concentrations of asbestos than those avoided due to lowering the 8-hour equates to 1.24 additional deaths found in mines today. The risks of these TWA PEL to 0.1 f/cc. avoided for every 1,000 miners exposed diseases still exist, however, and these d. Benefits of the Proposed 1.0 f/cc to asbestos at a concentration afforded risks are significant for miners exposed Excursion Limit. by the proposed excursion limit. to lower air concentrations of asbestos. We are proposing an asbestos e. Further Consideration of Benefits. Most diseases resulting from a current excursion limit of 1.0 f/cc as measured We believe that the pressure of public asbestos exposure may not become over a 30-minute period for metal and scrutiny and government intervention evident for another 20 to 30 years. Most nonmetal miners and coal miners has prompted mine operators to take likely, the full benefits will occur over working at surface work areas. We precautionary measures to limit miners’ a 65-year period following intend that the excursion limit protect exposures to asbestos. If public implementation of the lower PELs. The miners from the adverse health risks pressures were to subside, and we did rate at which the incidence of the associated with brief fiber-releasing not have a regulation limiting exposures cancers decreases depends on several episodes. We anticipate that some to 0.1 f/cc over an 8-hour shift, we factors including— mining operations will be subject to would not have a means to enforce the • Latency of onset of cancer, brief fiber-releasing episodes even after same level of protection provided in • Attrition of the mining workforce, other industries. • lowering airborne asbestos Changing rates of competing causes concentrations to the 8-hour TWA, full- Enforcement of the lower PELs of death, shift exposure limit. We have together with the direct support from • Dynamics of other risk factors, • insufficient data, however, to obtain a the federal government in education, Changes in life expectancy, and meaningful estimate of the frequency of identification, and elimination of the • Advances in cancer treatments. these episodes, the actual exposure asbestos hazard would increase It is not possible to quantify accurately concentrations, or the numbers of awareness and attention to the presence the complete dynamics of this process. miners exposed. Miners may encounter of asbestos on mine property. These Supplemental examination of brief fiber-releasing episodes from activities also would help focus efforts MSHA’s personal exposure samples exposure to commercial asbestos in on preventing exposures, thus providing using TEM analysis indicates that not asbestos-containing building materials miners with added health benefits. As all fibers counted by PCM are the (ACBM) or as settled dust containing seen in Chart VIII–1, mining operations currently regulated asbestos minerals. asbestos; while working on equipment with ore containing naturally occurring This is especially true for operations that may have asbestos-containing parts; asbestos seem to have reduced miners’ mining and processing wollastonite. We and while drilling, dozing, blasting, or exposures, perhaps due to their distinguish between different roof bolting in areas of naturally awareness of the lower exposure limits mineralogical fibers using TEM and occurring asbestos. OSHA promulgated in 1986.88 87 Nicholson, 1983; JRB Associates, 1983; OSHA Because we have little information (51 FR 22612), 1986; OSHA (53 FR 35609), 1988; from short-term exposure 88 NIOSH WoRLD pp. 16–17 and 19–23, 2003. OSHA (59 FR 40964), 1994. measurements, we estimate the benefit 89 NIOSH WoRLD, 2003.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00032 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43981

The estimates of the cancer deaths published articles document and cost would be about $91,500 per year for avoided by reducing the PELs discuss the health effects resulting from metal and nonmetal mines and about understate the total amount of benefit exposure to asbestos incident to living $44,600 per year for coal mines. These gained from this rule. These benefits do with a miner.90 costs represent less than 0.001 percent not include the reduced incidence of This analysis overstates health of the yearly revenues of $38.0 billion asbestosis-related disabilities. benefits to the extent that we do not for the metal and nonmetal mining Asbestosis cases often lead to account for differential risks posed by industry and $10.1 billion for the tremendous societal costs in terms of different types of fibers as identified by surface coal mining industry. PCM, and differences in the cancer health care utilization, loss of worker mortality risk for asbestos-exposed Table VIII–1 presents our estimate of productivity, and a decrease in the workers who smoke and those who do the total yearly compliance costs by quality of life of the affected individual. not. compliance strategy and mine size. The Similarly, MSHA’s analysis does not total costs reported are projected costs, quantify benefits among groups 2. Discussion of Costs in 2002 dollars, based on our incidentally exposed, such as miners’ The proposed rule would result in knowledge, experience, and available family members. We note that several total yearly costs of about $136,100. The information.

TABLE VIII–1.—SUMMARY OF YEARLY COMPLIANCE COSTS

Compliance strategy Total for metal Metal and nonmetal mine size Removal of and nonmetal Selective Wet methods Mill ventilation introduced mines mining asbetos

Small (<20)...... $1,058 $1,235 $747 $1,750 $4,790 Large (20–500) ...... 4,922 8,614 12,916 21,000 47,452 Large (>500) ...... 1,641 2,871 19,001 15,750 39,264

Total ...... 7,622 12,721 32,664 38,500 91,506 Compliance strategy Coal mine size Removal of Total for coal Selective Wet methods Mill ventilation introduced mines mining asbetos

Small (<20) ...... $875 $875 Large (20–500) ...... 12,250 12,250 Large (>500) ...... 31,500 31,500

90 NIOSH Publication No. 2002–113, May 2002.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00033 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 EP29JY05.005 43982 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

Compliance strategy Coal mine size Removal of Total for coal Selective Wet methods Mill ventilation introduced mines mining asbetos

Total ...... 44,625 44,625

B. Feasibility compliance with a lower alternative PEL record, we determined, and here certify, MSHA has concluded that the (0.05 f/cc 8-hour TWA). However, we that this proposed rule would not have requirements of this proposed rule cannot enforce an 8-hour TWA limit a significant economic impact on a would be both technologically and below 0.1 f/cc. The diversity of airborne substantial number of small entities. economically feasible. This proposed particles prevalent in mining The PREA for this proposed rule (RIN: rule is not a technology-forcing standard environments can interfere with sample 1219–AB24), Measuring and Controlling and does not involve activities on the analysis. Our existing standardized Asbestos Exposure, contains the factual frontiers of scientific knowledge. All sampling techniques minimize basis for this certification as well as devices that would be required by the interferences, but also impose complete details about data, equations, proposed rule are already available in limitations of accuracy below and methods used to calculate the costs the marketplace and have been used in concentrations of 0.1 f/cc. We address and quantified benefits. We have placed either the United States or the these limitations in more detail in the PREA in the rulemaking docket and Chapter III of the PREA that international mining community. We posted it on MSHA’s Web site at accompanies this proposed rule. These have concluded, therefore, that this http://www.msha.gov. proposed rule is technologically accuracy issues make it infeasible for us feasible. to enforce a concentration lower than E. Other Regulatory Considerations As previously estimated, the mining 0.1 f/cc airborne asbestos. industry would incur costs of about Although TEM provides greater 1. The National Environmental Policy $136,100 yearly to comply with this characterization of asbestos fibers than Act of 1969 (NEPA) PCM methodology, there is no proposed rule. These compliance costs We have reviewed this proposed rule predictable relationship between PCM represent well less than 0.001 percent of in accordance with the requirements of and TEM measures of exposure using the yearly revenues of the mines NEPA (42 U.S.C. 4321 et seq.), the covered by this rule, thus providing either method alone. We do not know of regulations of the Council on convincing evidence that the proposed a risk assessment correlating TEM Environmental Quality (40 CFR 1500), rule is economically feasible. measures of exposure with adverse health effects. TEM measurements, and the Department of Labor’s NEPA C. Alternatives Considered therefore, cannot be used as the basis for procedures (29 CFR 11) and have In our discussion of PELs in section an occupational exposure limit at this assessed its environmental impacts. We VII.B of this preamble, we recognize that time. Additionally, TEM is much more found that this proposed rule would there is a remaining residual risk of expensive and time consuming than have no significant impact on air, water, adverse health effects for miners PCM. If we were to analyze each of the or soil quality; plant or animal life; the exposed at the proposed asbestos 8-hour 2,184 personal exposure filters use of land; or other aspects of the TWA PEL. We considered proposing a (collected by us to determine full-shift human environment. lower PEL as a regulatory alternative to asbestos exposures from 2000 through 2. Paperwork Reduction Act of 1995 further reduce the risk of adverse health 2003) using TEM, rather than PCM, it effects from a working lifetime of would cost us about $186,000 to This proposed rule contains no exposure. Assuming 0.05 f/cc, for $852,000 more. The mine operator’s information collection or recordkeeping example, and interpolating the data costs would increase in so far as the requirements. Thus, there are no from OSHA’s risk assessment operator would do comparable additional paperwork burden hours and summarized in Table VI–4 of this sampling. We expect the operator to related costs associated with the preamble, there would be about 1.68 sample to determine whether control proposed rule. Accordingly, the cancer deaths per 1,000 miners exposed measures are needed, what controls Paperwork Reduction Act requires no to asbestos at 0.05 f/cc for 45 years. The might be needed, and the effectiveness further agency action or analysis. 1.68 cancer mortality rate is 50 percent of controls when implemented. A less than the rate of 3.36 cancer deaths number of commenters supported our 3. The Unfunded Mandates Reform Act per 1,000 exposed miners calculated for continued use of PCM for the initial of 1995 the proposed 0.1 f/cc PEL; and about 97 analysis of asbestos samples. percent less than we estimate for our We conclude that it is not feasible to This proposed rule does not include existing standard (64.12 cancer deaths regulate the mining industry below the any Federal mandate that may result in per 1,000 exposed miners). We also proposed limit at this time. We welcome increased expenditures by State, local, project that reducing miner’s exposure comments on the exposure limit or tribal governments; nor would it to an 8-hour TWA of 0.05 f/cc would proposed and the rationale used for significantly or uniquely affect small reduce the expected cases of asbestosis choosing it over the alternative governments. It would not increase to about 50 percent less than at the discussed above. private sector expenditures by more proposed 8-hour TWA PEL. D. Regulatory Flexibility Analysis (RFA) than $100 million annually. About 85 percent of the 123 sampled Accordingly, the Unfunded Mandates mines are already well in compliance and Small Business Regulatory Enforcement Fairness Act (SBREFA) Reform Act requires no further agency with the 0.1 f/cc proposed PEL. We action or analysis. believe that, theoretically, almost all of Based on our data, our experience, the mining industry could be in and information submitted to the

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00034 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43983

4. Treasury and General Government not ‘‘have substantial direct effects on OSHA Reference Method contains these Appropriations Act of 1999, (Section one or more Indian tribes, on the requirements. 654: Assessment of Impact of Federal relationship between the Federal 29 CFR 1910.1001 Appendix A: OSHA Regulations and Policies on Families) government and Indian tribes, or on the Reference Method—Mandatory This proposed rule would have no distribution of power and affect on family well-being or stability, responsibilities between the Federal This mandatory appendix specifies the marital commitment, parental rights or government and Indian tribes.’’ procedure for analyzing air samples for Accordingly, Executive Order 13175 asbestos and specifies quality control authority, or income or poverty of procedures that must be implemented by families and children. Accordingly, the requires no further agency action or analysis. laboratories performing the analysis. The Treasury and General Government sampling and analytical methods described Appropriations Act requires no further 10. Executive Order 13211: Actions below represent the elements of the available agency action, analysis, or assessment. Concerning Regulations That monitoring methods (such as Appendix B of their regulation, the most current version of 5. Executive Order 12630: Government Significantly Affect Energy Supply, Distribution, or Use the OSHA method ID–160, or the most Actions and Interference With current version of the NIOSH Method 7400). Constitutionally Protected Property In accordance with Executive Order All employers who are required to conduct Rights 13211, we have reviewed this proposed air monitoring under paragraph (d) of the This proposed rule would not rule for its impact on the supply, [OSHA] standard are required to utilize implement a policy with takings distribution, and use of energy. This analytical laboratories that use this implications. Accordingly, Executive proposed rule would regulate both the procedure, or an equivalent method, for collecting and analyzing samples. Order 12630 requires no further agency coal and metal and nonmetal mining action or analysis. sectors. Because this proposed rule Sampling and Analytical Procedure would result in negligible yearly costs of 1. The sampling medium for air samples 6. Executive Order 12988: Civil Justice less than 0.001 percent of revenues to Reform shall be mixed cellulose ester filter the coal mining industry, the proposed membranes. These shall be designated by the We have drafted and reviewed this rule would neither significantly reduce manufacturer as suitable for asbestos proposed rule in accordance with the supply of coal nor significantly counting. See below for rejection of blanks. Executive Order 12988. We wrote this increase its price. Regulation of the 2. The preferred collection device shall be proposed rule to provide a clear legal metal and nonmetal sector of the mining the 25-mm diameter cassette with an open- standard for affected conduct and industry has no significant impact on faced 50-mm electrically conductive carefully reviewed it to eliminate the supply, distribution, or use of extension cowl. The 37-mm cassette may be used if necessary but only if written drafting errors and ambiguities, thus energy. This proposed rule is not a justification for the need to use the 37-mm minimizing litigation and undue burden filter cassette accompanies the sample results on the Federal court system. MSHA has ‘‘significant energy action,’’ because it in the employee’s exposure monitoring determined that this proposed rule would not be ‘‘likely to have a record. Do not reuse or reload cassettes for would meet the applicable standards in significant adverse effect on the supply, asbestos sample collection. section 3 of Executive Order 12988. distribution, or use of energy’’ 3. An air flow rate between 0.5 liter/min ‘‘(including a shortfall in supply, price and 2.5 liters/min shall be selected for the 7. Executive Order 13045: Protection of increases, and increased use of foreign 25-mm cassette. If the 37-mm cassette is Children From Environmental Health supplies).’’ Accordingly, Executive used, an air flow rate between 1 liter/min and Risks and Safety Risks Order 13211 requires no further agency 2.5 liters/min shall be selected. This proposed rule would have no action or analysis. 4. Where possible, a sufficient air volume for each air sample shall be collected to yield adverse impact on children. This 11. Executive Order 13272: Proper between 100 and 1,300 fibers per square proposed asbestos standard might Consideration of Small Entities in millimeter on the membrane filter. If a filter benefit children by reducing Agency Rulemaking darkens in appearance or if loose dust is seen occupational exposure limits, thus on the filter, a second sample shall be started. reducing their risk of disease from take- In accordance with Executive Order 5. Ship the samples in a rigid container home contamination. Accordingly, 13272, we have thoroughly reviewed with sufficient packing material to prevent Executive Order 13045 requires no this proposed rule to assess and take dislodging the collected fibers. Packing further agency action or analysis. appropriate account of its potential material that has a high electrostatic charge impact on small businesses, small on its surface (e.g., expanded polystyrene) 8. Executive Order 13132: Federalism governmental jurisdictions, and small cannot be used because such material can This proposed rule would not have organizations. As discussed in section cause loss of fibers to the sides of the cassette. ‘‘federalism implications,’’ because it VIII.C. above and in chapter V of the 6. Calibrate each personal sampling pump would not ‘‘have substantial direct PREA, MSHA has determined and before and after use with a representative effects on the States, on the relationship certified that this proposed rule would filter cassette installed between the pump between the national government and not have a significant economic impact and the calibration devices. the States, or on the distribution of on a substantial number of small 7. Personal samples shall be taken in the power and responsibilities among the entities. ‘‘breathing zone’’ of the employee (i.e., various levels of government.’’ attached to or near the collar or lapel near the IX. Copy of the OSHA Reference Accordingly, Executive Order 13132 worker’s face). Method (ORM) requires no further agency action or 8. Fiber counts shall be made by positive phase contrast using a microscope with an 8 analysis. MSHA’s existing asbestos standards require that the analyst determine fiber to 10 X eyepiece and a 40 to 45 X objective 9. Executive Order 13175: Consultation for a total magnification of approximately concentrations using a phase contrast 400 X and a numerical aperture of 0.65 to and Coordination With Indian Tribal microscopy analytical method with Governments 0.75. The microscope shall also be fitted with 400–450X magnification and count a green or blue filter. This proposed rule would not have fibers 5 µm or longer having a length to 9. The microscope shall be fitted with a ‘‘tribal implications,’’ because it would diameter aspect ratio of at least 3:1. The Walton-Beckett eyepiece graticule calibrated

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00035 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 43984 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

for a field diameter of 100 micrometers (+/ microscopist counting slides shall establish a Amandus, H.E., and R. Wheeler. ‘‘The ¥2 micrometers). statistically designed quality assurance Morbidity and Mortality of Vermiculite 10. The phase-shift detection limit of the program involving blind recounts and Miners and Millers Exposed to Tremolite- microscope shall be about 3 degrees comparisons between microscopists to Actinolite: Part II. Mortality,’’ American measured using the HSE phase shift test slide monitor the variability of counting by each Journal of Industrial Medicine, 11(1):15– as outlined below. microscopist and between microscopists. In a 26, 1987. a. Place the test slide on the microscope company with more than one laboratory, the Amandus, H.E., R. Althouse, W.K.C. Morgan, stage and center it under the phase objective. program shall include all laboratories and E.N. Sargent, and R. Jones. ‘‘The Morbidity b. Bring the blocks of grooved lines into shall also evaluate the laboratory-to- and Mortality of Vermiculite Miners and focus. laboratory variability. Millers Exposed to Tremolite-Actinolite: Note: The slide consists of seven sets of 2.a. Interlaboratory program. Each Part III. Radiographic Findings,’’ American grooved lines (ca. 20 grooves to each block) laboratory analyzing asbestos samples for Journal of Industrial Medicine, 11(1):27– in descending order of visibility from sets 1 compliance determination shall implement 37, 1987. to 7, seven being the least visible. The an interlaboratory quality assurance program American Conference of Governmental requirements for asbestos counting are that that as a minimum includes participation of Industrial Hygienists-American Industrial the microscope optics must resolve the at least two other independent laboratories. Hygiene Association, Joint ACGIH–AIHA grooved lines in set 3 completely, although Each laboratory shall participate in round Aerosol Hazards Evaluation Committee. they may appear somewhat faint, and that the robin testing at least once every 6 months ‘‘Background Documentation on grooved lines in sets 6 and 7 must be with at least all the other laboratories in its Evaluation of Occupational Exposure to invisible. Sets 4 and 5 must be at least interlaboratory quality assurance group. Each Airborne Asbestos,’’ American Industrial partially visible but may vary slightly in laboratory shall submit slides typical of its Hygiene Association Journal, February visibility between microscopes. A own work load for use in this program. The 1975, pp. 91–103. microscope that fails to meet these round robin shall be designed and results American Thoracic Society. ‘‘Diagnosis and requirements has either too low or too high analyzed using appropriate statistical Initial Management of Nonmalignant a resolution to be used for asbestos counting. methodology. Diseases Related to Asbestos,’’ American c. If the image deteriorates, clean and 2.b. All laboratories should also participate Journal of Respiratory and Critical Care adjust the microscope optics. If the problem in a national sample testing scheme such as Medicine, 170:691–715, 2004. persists, consult the microscope the Proficiency Analytical Testing Program Armstrong, B.K., N.H. de Klerk, A.W. Musk, manufacturer. (PAT), or the Asbestos Registry sponsored by and M.S.T. Hobbs. ‘‘Mortality in Miners 11. Each set of samples taken will include the American Industrial Hygiene Association and Millers of Crocidolite in Western 10 percent blanks or a minimum of 2 field (AIHA). Australia, British Journal of Industrial blanks. These blanks must come from the 3. All individuals performing asbestos Medicine, 45:5–13, 1988. same lot as the filters used for sample analysis must have taken the NIOSH course Asbestos International Association (AIA). collection. The field blank results shall be for sampling and evaluating airborne asbestos ‘‘Airborne Asbestos Fiber Concentrations at averaged and subtracted from the analytical dust or an equivalent course. Workplaces by Light Microscopy results before reporting. A set consists of any 4. When the use of different microscopes (Membrane Filter Method),’’ AIA Health sample or group of samples for which an contributes to differences between counters and Safety Recommended Technical evaluation for this standard must be made. and laboratories, the effect of the different Method No. 1 (RTM1), London, September Any samples represented by a field blank microscope shall be evaluated and the 7, 1979. having a fiber count in excess of the microscope shall be replaced, as necessary. Baron, Paul A. ‘‘Measurement of Airborne detection limit of the method being used 5. Current results of these quality Fibers: A Review,’’ Industrial Health, shall be rejected. assurance programs shall be posted in each 39:39–50, 2001. 12. The samples shall be mounted by the laboratory to keep the microscopists Becker, Nikolaus, Jurgen Berger, and Ulrich acetone/triacetin method or a method with informed. Bolm-Audorff. ‘‘Asbestos Exposure and an equivalent index of refraction and similar [57 FR 24330, June 8, 1992; 59 FR 40964, Malignant Lymphomas— a Review of the clarity. Aug. 10, 1994] Epidemiological Literature,’’ International 13. Observe the following counting rules. X. References Cited in the Preamble Archives of Occupational and a. Count only fibers equal to or longer than Environmental Health, 74:459–469, 2001. 5 micrometers. Measure the length of curved Agency for Toxic Substances and Disease Becklake, Margaret R. ‘‘Clinical fibers along the curve. Registry (ATSDR). Perchlorate Measurements in Quebec Chrysotile b. In the absence of other information, Contamination in the Citizens Utilities’ Miners: Use for Future Protection of count all particles as asbestos that have a Suburban and Security Park Water Service Workers,’’ Annals New York Academy of length-to-width ratio (aspect ratio) of 3:1 or Areas, Prepared by California Department Sciences, pp. 23–29, 1979. greater. of Health Services under CERCLIS No. Berry, G., and H.C. Lewinsohn. ‘‘Dose- c. Fibers lying entirely within the CAD980358832, March 18, 1998. boundary of the Walton-Beckett graticule Response Relationships for Asbestos- field shall receive a count of 1. Fibers Agency for Toxic Substances and Disease Related Disease: Implications for Hygiene crossing the boundary once, having one end Registry (ATSDR). Toxicological Profile for Standards, Part I. Morbidity,’’ Annals New within the circle, shall receive the count of Asbestos (Update), Prepared by Syracuse York Academy of Sciences, pp. 185–194, Research Corp. under Contract No. 205– 1979. one half (1⁄2). Do not count any fiber that crosses the graticule boundary more than 1999–00024, U.S. Department of Health Berry, G., and M.L. Newhouse. ‘‘Mortality of once. Reject and do not count any other and Human Services, Public Health Workers Manufacturing Friction Materials fibers even though they may be visible Service, September 2001. Using Asbestos,’’ British Journal of outside the graticule area. Agency for Toxic Substances and Disease Industrial Medicine, 40:1–7, 1983. d. Count bundles of fibers as one fiber Registry (ATSDR). Report on the Expert Bolton, C., A. Richards, and P. Ebden. unless individual fibers can be identified by Panel on Health Effects of Asbestos and ‘‘Asbestos-Related Disease,’’ Hospital observing both ends of an individual fiber. Synthetic Vitreous Fibers: The Influence of Medicine, 63(3):148–151, March 2002. e. Count enough graticule fields to yield Fiber Length (Proceedings of panel Britton, Mark. ‘‘The Epidemiology of 100 fibers. Count a minimum of 20 fields; discussion, October 29–30, 2002, New Mesothelioma,’’ Seminars in Oncology, stop counting at 100 fields regardless of fiber York City), Prepared by Eastern Research 29(1):18–25, February 2002. count. Group, Inc., March 17, 2003. Browne, Kevin. ‘‘The Quantitative Risks of 14. Blind recounts shall be conducted at Amandus, H.E., R. Wheeler, J. Jankovic, and Mesothelioma and Lung Cancer in Relation the rate of 10 percent. J. Tucker. ‘‘The Morbidity and Mortality of to Asbestos Exposure,’’ Annals of Vermiculite Miners and Millers Exposed to Occupational Hygiene (Letters to the Quality Control Procedures Tremolite-Actinolite: Part I. Exposure Editor), 45(4):327–329, 2001. 1. Intralaboratory program. Each laboratory Estimates,’’ American Journal of Industrial Browne, Kevin, and J. Bernard L. Gee. and/or each company with more than one Medicine, 11(1):1–14, 1987. ‘‘Asbestos and Laryngeal Cancer,’’ Annals

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00036 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43985

of Occupational Hygiene, 44:239–250, Doll, Richard. ‘‘Mortality from Lung Cancer International Agency for Research on Cancer 2000. in Asbestos Workers,’’ British Journal of (IARC). ‘‘Asbestos,’’ Monographs (Volume Carbone, Michele, Robert A. Kratzke, and Industrial Medicine, 12:81–86, 1955. 14), Supplement 7, p. 106, 1987. Joseph R. Testa. ‘‘The Pathogenesis of Donaldson, K., R.E. Bolton, A. Jones, G.M. International Commission on Radiation Mesothelioma,’’ Seminars in Oncology, Brown, M.D. Robertson, J. Slight, H. Cowie, Protection (ICRP), Prepared by the Task 29(1):2–17, February 2002. and J.M.G. Davis. ‘‘Kinetics of the Group on Lung Dynamics for Committee II Clark, R.L. ‘‘Metallic Substrates as an Internal Bronchoalveolar Leucocyte Response in of the ICRP. ‘‘Deposition and Retention Standard for Transmission Electron Rats during Exposure to Equal Airborne Models for Internal Dosimetry of the Microscope,’’ Annals of the Institute for the Mass Concentrations of Quartz, Chrysotile Human Respiratory Tract,’’ Health Physics, Certification of Engineering Technicians, Asbestos, or Titanium Dioxide,’’ Thorax, 12:173–207, 1966. [‘‘Errata and Revisions 1977. 43:525–533, 1988. to Health Physics 12, 173 (1966),’’ Health Cookson, W.O.C.M., N.H. de Klerk, A.W. Eagen, Tomas M.L., Amund Gulsvik, Geir E. Physics, 13:1251, 1967.] Musk, B.K. Armstrong, J.J. Glancy, and Eide, and Per S. Bakke. ‘‘Occupational International Organization for M.S.T. Hobbs. ‘‘Prevalence of Radiographic Airborne Exposure and the Incidence of Standardization (ISO). ‘‘Air quality— Asbestosis in Crocidolite Miners and Respiratory Symptoms and Asthma,’’ Determination of the number concentration Millers at Wittenoom, Western Australia,’’ American Journal of Respiratory Critical of airborne inorganic fibres by phase British Journal of Industrial Medicine, Care Medicine, 166:933–938, 2002. contrast microscopy—Membrane filter 43:450–457, 1986. Enarson, D.A., Valerie Embree, Lonia method,’’ ISO 8672:1993(E). Cotran, Ramzi S., Vinay Kumar, and Tucker Maclean, and S. Grzybowski. ‘‘Respiratory Irwig, L.M., R.S.J. du Toit, G.K. Sluis-Cremer, Collins. Robbins Pathological Basis of Health in Chrysotile Asbestos Miners in A. Solomon, R. Glyn Thomas, P.P.H. Disease, Sixth Edition (W.B. Saunders British Columbia: A Longitudinal Study,’’ Hamel, I. Webster, and T. Hastie. ‘‘Risk of Company, Philadelphia), pp. 732–734, British Journal of Industrial Medicine, Asbestosis in Crocidolite and Amosite 1999. 45:459–463, 1988. Mines in South Africa,’’ Annals New York Crane, Dan. Letter to Kelly Bailey dated May Finkelstein, Murray M. ‘‘Asbestosis in Long- Academy of Sciences, pp. 35–52, 1979. 16, 1989. (1219–AB24–COMM–28–10). Term Employees of an Ontario Asbestos- JRB Associates. ‘‘Benefits Assessment of Dave, S.K., L.J. Bhagia, P.K. Mazumdar, G.C. Cement Factory,’’ American Review of Emergency Temporary and Proposed Patel, P.K. Kulkarni, and S.K. Kashyap. Respiratory Disease, 125:496–501, 1982. Asbestos Standards, Final Report,’’ ‘‘The Correlation of Chest Radiograph and Finkelstein, M.M. ‘‘Mortality among Long- Prepared by Marthe B. Kent, William G. Pulmonary Function Tests in Asbestos Term Employees of an Ontario Asbestos- Perry, and Christine B. New for OSHA Miners and Millers,’’ Indian Journal of Cement Factory,’’ British Journal of Office of Regulatory Analysis, November 3, Chest Disease and Allied Sciences, 38:81– Industrial Medicine, 40:138–144, 1983. 1983. 89, 1996. Finkelstein, Murray M. ‘‘Potential Pitfall in Kelse, John W., and C. Sheldon Thompson. Davis, J.M.G., S.T. Beckett, R.E. Bolton, and Using Cumulative Exposure in Exposure- ‘‘The Regulatory and Mineralogical K. Donaldson. ‘‘The Effects of Intermittent Response Relationships: Demonstration Definitions of Asbestos and their Impact on High Asbestos Exposure (Peak Dose Levels) and Discussion,’’ American Journal of Amphibole Dust Analysis,’’ American on the Lungs of Rats,’’ British Journal of Industrial Medicine, 28:41–47, 1995. Industrial Hygiene Association Journal, Experimental Pathology, 61:272–280, 1980. Davis, J.M.G., S.T. Beckett, R.E. Bolton, and Fischer, M., S. Gunther, and K.-M. Muller. 50:613–622, 1989. K. Donaldson. ‘‘A Comparison of the ‘‘Fibre-Years, Pulmonary Asbestos Burden Lane, R.E. (Chairman) et al., Subcommittee Pathological Effects in Rat of the UICC and Asbestosis,’’ International Journal of on Asbestos, Committee on Hygiene, Reference Samples of Amosite and Hygiene and Environmental Health, British Occupational Hygiene Society. Chrysotile with Those of Amosite and 205:245–248, 2002. ‘‘Hygiene Standards for Chrysotile Chrysotile Collected from the Factory Gibbs, Graham W., and R.S.J. du Toit. Asbestos Dust,’’ Annals of Occupational Environment,’’ In: Biological Effects of ‘‘Environmental Considerations in Hygiene, 11:47–69, 1968. (1219–AB24– Mineral Fibres, J.C. Wagner (Editor-in- Surveillance of Asbestos Miners and COMM–29–2) Chief), IARC Scientific Publications No. 30 Millers,’’ Annals New York Academy of Langer, Arthur M., Arthur N. Rohl, Mary (2 volumes), pp. 285–292, 1980. Sciences, pp. 163–178, 1979. Snow Wolf, and Irving J. Selikoff. Davis, J.M.G., J. Addison, R.E. Bolton, K. Global Environmental & Technology ‘‘Asbestos, Fibrous Minerals and Acicular Donaldson, A.D. Jones and T. Smith. ‘‘The Foundation (GETF). ‘‘Report of Findings Cleavage Fragments: Nomenclature and Pathogenicity of Long versus Short Fibre and Recommendations on the Use and Biological Properties,’’ Dusts and Disease, Samples of Amosite Administered to Rats Management of Asbestos,’’ Asbestos 1979. (1219–AB24–COMM–29–11) by Inhalation and Intraperitoneal Strategies, 2003. Leake, Bernard E. (Chairman), et al. Injection,’’ British Journal of Experimental Goldstein, B., and F.S.J. Coetzee. ‘‘Nomenclature of Amphiboles: Report of Pathology, 67:415–430, 1986. ‘‘Experimental Malignant Mesotheliomas the Subcommittee on Amphiboles of the Davis, J.M.G., and A.D. Jones. ‘‘Comparison in Baboons,’’ South African Journal of International Mineralogical Association, of the Pathogenicity of Long and Short Science, 86:89–93, February 1990. Commission on New Minerals and Mineral Fibres of Chrysotile Asbestos in Rats,’’ Greenberg, Morris. ‘‘Biological Effects of Names,’’ Canadian Mineralogist, 35:219– British Journal of Experimental Pathology, Asbestos: New York Academy of Sciences 246, 1997. 69:717–737, 1988. 1964,’’ American Journal of Industrial Lemen, Richard A. ‘‘Asbestos in Brakes,’’ Delpierre, Stephane, Yves Jammes, Marie Medicine (Historical Perspective), 43:543– October 16, 2003. [Paper received from Jose Delvogo-Gori, and Marion Faucher. 552, 2003. Ralph D. Zumwalde (NIOSH) via Tom ‘‘High Prevalence of Reversible Airway Harper, Martin, and Al Bartolucci. Simons (EPA), December 5, 2003.] Obstruction in Asbestos-Exposed ‘‘Preparation and Examination of Proposed Liddell, Douglas. Letter to the Editor, Workers,’’ Archives of Environmental Consensus Reference Standards for Fiber- ‘‘Asbestos and Cancer,’’ Annals of Health, 57(5):441–445, September/October, Counting,’’ American Industrial Hygiene Occupational Hygiene, 45(4):329–335, 2002. Association Journal, 64:283–287, 2003. 2001. Dement, J.M., R.L. Harris, M.J. Symons, and Henderson, Vivian L., and Philip E. Maltoni, Cesare. ‘‘Call for an International C. Shy. ‘‘Estimates of Dose-Response for Enterline. ‘‘Asbestos Exposure Factors Ban on Asbestos,’’ Toxicology and Respiratory Cancer among Chrysotile Associated with Excess Cancer and Industrial Health, 15:529–531, 1999. Asbestos Textile Workers,’’ Annals of Respiratory Disease Mortality,’’ Annals Manning, Christopher B., Val Vallyathan, and Occupational Hygiene, 26(14):869–887, New York Academy of Sciences Brooke Mossman. ‘‘Diseases Caused by 1982. (prepublication copy), 1979. Asbestos: Mechanisms of Injury and Dodson, Ronald F., Mark A.L. Atkinson, and Hodgson, John T., and Andrew Darnton. Disease Development, International Jeffrey L. Levin. ‘‘Asbestos Fiber Length as ‘‘The Quantitative Risks of Mesothelioma Immunopharmacology, 2:191–200, 2002. Related to Potential Pathogenicity: A and Lung Cancer in Relation to Asbestos McDonald, J. Corbett, and F. Douglas K. Critical Review,’’ American Journal of Exposure,’’ Annals of Occupational Liddell. ‘‘Mortality in Canadian Miners Industrial Medicine, 44:291–297, 2003. Hygiene, 44(8):565–601, 2000. and Millers Exposed to Chrysotile, Annals

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00037 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 43986 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

New York Academy of Sciences, pp. 1–9, Exposure to Airborne Asbestos on Mining Ojajarvi, I. Anneli, Timo J. Partanen, Anders 1979. Properties, dated March 2, 2000. Ahlbom, Paolo Boffetta, Timo Hakulinen, McDonald, J.C., F.D.K. Liddell, G.W. Gibbs, Mossman, Brooke. In Report of the Expert Nadia Jourenkova, Timo P. Kauppinen, G.E. Eyssen, and A.D. McDonald. ‘‘Dust Panel on Health Effects of Asbestos and Manolis Kogevinas, Miquel Porta, Harri U. Exposure and Mortality in Chrysotile Synthetic Vitreous Fibers: The Influence of Vainio, Elisabete Weiderpass, and Mining, 1910–75,’’ British Journal of Fiber Length, (Proceedings of Panel, Catharina H. Wesseling. ‘‘Occupational Industrial Medicine, 37:11–24, 1980. October 29–30, 2002, New York City), Exposures and Pancreatic Cancer: A Meta- (A) McDonald, J.C., A.D. McDonald, B. Prepared by Eastern Research Group for the Analysis,’’ Occupational and Armstrong, and P. Sebastien. ‘‘Cohort Agency for Toxic Substances and Disease Environmental Medicine, 57:316–324, study of mortality of vermiculite miners Registry (ATSDR), March 17, 2003. 2000. exposed to tremolite,’’ British Journal of National Institute for Occupational Safety Orenstein, Marla R., and Marc B. Schenker. Industrial Medicine, 43:436–444, 1986. and Health (NIOSH). Criteria for a ‘‘Environmental Asbestos Exposure and (B) McDonald, J.C., P. Sebastien, and B. Recommended Standard Occupational Mesothelioma,’’ Pulmonary Medicine Armstrong. ‘‘Radiological Survey of Past Exposure to Asbestos, U.S. Department of (Current Opinion), 6:371–377, 2000. and Present Vermiculite Miners Exposed to Health, Education, and Welfare, 1972. Osinubi, Omowunmi Y.O., Michael Tremolite,’’ British Journal of Industrial National Institute for Occupational Safety Gochfeld, and Howard M. Kipen. ‘‘Health Medicine, 43:445–449, 1986. and Health (NIOSH). Report to Congress on Effects of Asbestos and Nonasbestos McDonald, J.C., A.D. McDonald, P. Sebastien, Workers’ Home Contamination Study Fibers,’’ Environmental Health and K. Moy. ‘‘Health of Vermiculite Miners Conducted Under the Workers’ Family Perspectives, 108 (Supplement 4): 665–674, Exposed to Trace Amounts of Fibrous Protection Act, DHHS (NIOSH) Publication 2000. Tremolite,’’ British Journal of Industrial No. 95–123 (September 1995). Pang, Thomas W.S. ‘‘Precision and Accuracy Medicine, 45:630–634, 1988. National Institute for Occupational Safety of Asbestos Fiber Counting by Phase McDonald, J.C., F.D.K. Liddell, A. Dufresne, and Health (NIOSH). Protect Your Family: Contrast Microscopy,’’ American Industrial and A.D. McDonald. ‘‘The 1891–1920 Birth Reduce Contamination at Home, DHHS Hygiene Association Journal, 61:529–538, Cohort of Quebec Chrysotile Miners and (NIOSH) Publication No. 97–125 (1997). 2000. Millers: Mortality 1976–1988,’’ British National Institute for Occupational Safety Paustenbach, Dennis J., Richard O. Richter, Journal of Industrial Medicine, 50:1073– and Health (NIOSH). Protecting Workers’ Brent L. Finley, and Patrick J. Sheehan. 1081, 1993. Families: A Research Agenda: Report of the ‘‘An Evaluation of the Historical Exposures McDonald, A.D., B.W. Case, A. Churg, A. Workers’ Family Protection Task Force, of Mechanics to Asbestos in Brake Dust,’’ Dufresne, G.W. Gibbs, P. Sebastien, and DHHS (NIOSH) Publication No. 2002–113 Applied Occupational and Environmental Hygiene, 18:786–804, 2003. J.C. McDonald. ‘‘Mesothelioma in Quebec (2002). National Institute for Occupational Safety Peacock, C., S.J. Copley, and D.M. Hansell. Chrysotile Miners and Millers: and Health (NIOSH). Division of ‘‘Asbestos-Related Benign Pleural Disease,’’ Epidemiology and Aetiology,’’ Annals of Respiratory Disease Studies, Work Related Clinical Radiology (Review), 55:422–432, Occupational Hygiene, 41(6):707–719, Lung Disease Surveillance Report 2002 2000. 1997. [World 2003], DHHS (NIOSH) Publication Peipins, Lucy A., Michael Lewin, Sharon McGavran, Patricia D., Charles J. Butterick, No. 2003–111, May 2003. Campolucci, Jeffrey A. Lybarger, Aubrey and Arnold R. Brody. ‘‘Tritiated National Institute for Occupational Safety Miller, Dan Middleton, Christopher Weis, Thymidine Incorporation and the and Health (NIOSH). Pocket Guide to Michael Spence, Brad Black, and Vikas Development of an Interstitial Lesion in the Chemical Hazards, DHHS (NIOSH) Kapil. ‘‘Radiographic Abnormalities and Bronchiolar-Alveolar Regions of the Lungs Publication No. 2004–103, October 2003. Exposure to Asbestos-Contaminated of Normal and Complement Deficient Mice Nayebzadeh, Ataollah, Andre Dufresne, Vermiculite in the Community of Libby, after Inhalation of Chrysotile Asbestos,’’ Bruce Case, Hojatolah Vali, A.E. Williams- Montana, USA,’’ Environmental Health Journal of Environmental Pathology, Jones, Robert Martin, Charles Normand, Perspectives, 111(14):1753–1759, Toxicology and Oncology (JEPTO), 9(5)/ and James Clark. ‘‘Lung Mineral Fibers of November 2003. 9(6):377–392, 1989. Former Miners and Millers from Thetford- Peto, J., R. Doll, S.V. Howard, L.J. Kinlen, and McLaughlin, Joseph K., and Loren Lipworth. Mines and Asbestos Regions: A H.C. Lewinsohn. ‘‘A Mortality Study ‘‘Epidemiologic Aspects of Renal Cell Comparative Study of Fiber Concentration among Workers in an English Asbestos Cancer,’’ Seminars in Oncology, 27(2):115– and Dimension, Archives of Environmental Factory,’’ British Journal of Industrial 123, April 2000. Health, 56(1):65–76, January/February Medicine, 34:169–173, 1977. Meeker, G.P., A.M. Bern, I.K. Brownfield, 2001. Peto, Julian. ‘‘Lung Cancer Mortality in H.A. Lowers, S.J. Sutley, T.M. Hoefen, and Nicholson, William J., Irving J. Selikoff, Relation to Measured Dust Levels in an J.S. Vance. ‘‘The Composition and Herbert Seidman, Ruth Lillis, and Paul Asbestos Textile Factory,’’ In: Biological Morphology of Amphiboles from the Rainy Formby. ‘‘Long-Term Mortality Experience Effects of Mineral Fibres, J.C. Wagner Creek Complex, Near Libby, Montana,’’ of Chrysotile Miners and Millers in (Editor-in-Chief), IARC Scientific American Mineralogist, 88:1955–1969, Thetford Mines, Quebec,’’ Annals New Publications No. 30 (2 volumes), pp. 829– 2003. York Academy of Sciences, pp. 11–21, 836, 1980. Mine Safety and Health Administration 1979. Peto, J., H. Seidman, and I.J. Selikoff. (MSHA). Walter Bank, ‘‘Asbestiform and/or Nicholson, William J. ‘‘Quantitative Risk ‘‘Mesothelioma Mortality in Asbestos Fibrous Minerals in Mines, Mills, and Assessment for Asbestos Related Cancers,’’ Workers: Implications for Models of Quarries,’’ Informational Report IR 1111, Prepared in conjunction with U.S. Carcinogenesis and Risk Assessment,’’ 1980. Department of Labor, Occupational Safety British Journal of Cancer, 45:124–135 Mine Safety and Health Administration and Health Administration (OSHA), Office (prepublication copy), 1982. (MSHA). ‘‘Asbestos Hazards in the Mining of Carcinogen Standards, under OSHA Pohlabeln, H., P. Wild, W. Schill, W. Ahrens, Industry,’’ Health Hazard Information Contract No. J–9–F–2–0074, October 1983. I. Jahn, U. Bolm-Audorff, and K-H Jockel. Card No. 21, March 2000. Nicholson, William J. ‘‘The Carcinogenicity ‘‘Asbestos Fibre Years and Lung Cancer: A Mine Safety and Health Administration of Chrysotile Asbestos—A Review,’’ Two Phase Case-Control Study with Expert (MSHA). ‘‘Chapter 8 Asbestos Fibers,’’ Industrial Health, 39:57–64,2001. Exposure Assessment,’’ Occupational and Metal/Nonmetal Health Inspection Nolan, R.P., A.M. Langer, and Richard Environmental Medicine, 59:410–414, Procedures Handbook (PH04–IV–5), Wilson. ‘‘A Risk Assessment for Exposure 2002. November 2003; and ‘‘Chapter 8 Asbestos,’’ to Grunerite Asbestos (Amosite) in an Iron Ramanathan, A.L., and V. Subramanian. MSHA Handbook Series: Coal Mine Health Ore Mine,’’ Paper presented at the National ‘‘Present Status of Asbestos Mining and Inspection Procedures (Handbook No. 89– Academy of Sciences Colloquium Related Health Problems in India—A V–1), February 1989. ‘‘Geology, Mineralogy, and Human Survey,’’ Industrial Health, 39:309–315, Mine Safety and Health Administration Welfare,’’ Irvine, CA, November 8–9, 1998. 2001. (MSHA). Program Information Bulletin No. In: Proceedings of the National Academy of Reeves, Andrew L., Henry E. Puro, and Ralph P00–3 from J. Davitt McAteer, re: Potential Science, 96(7):3412–3419, March 1999. G. Smith. ‘‘Inhalation Carcinogenesis from

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00038 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43987

Various Forms of Asbestos,’’ Work Exposure and Long-Term a National Priority,’’ EPA Action Update # Environmental Research, 8:178–202, 1974. Observation,’’ Annals New York Academy 12, February 26, 2002. Reger, Robert, and W.K. Morgan. ‘‘On talc, of Sciences, pp. 61–89, 1979. U.S. Environmental Protection Agency (EPA, tremolite, and tergiversation,’’ British Seidman, Herbert. ‘‘Short-Term Asbestos Region 2). World Trade Center Background Journal of Industrial Medicine, 47:505–507, Work Exposure and Long-Term Study Report, Prepared for U.S. Federal 1990. Observation,’’ from OSHA Asbestos Docket Emergency Management Agency, IAG No.: Roach, Huw D., Gareth J. Davies, Richard (Exh-261-A), July 1984 Updating. EMW–2002–IA–0127, April 2003. Attanoos, Michael Crane, Haydn Adams, Selden, A.I., N.P. Berg, E.A.L. Lundgren, G. U.S. Environmental Protection Agency (EPA). and Sian Phillips. ‘‘Asbestos: When the Hillerdal, N.-G. Wik, C.-G. Ohlson, and L.S. ‘‘40 CFR Part 63, National Emission Dust Settles—An Imaging Review of Bodin. ‘‘Exposure to Tremolite Asbestos Standards for Hazardous Air Pollutants: Asbestos-Related Disease,’’ RadioGraphics, and Respiratory Health in Swedish Taconite Iron Ore Processing; Final Rule,’’ 22:S167–S184, 2002. Dolomite Workers,’’ Occupational and Federal Register (68 FR 61868), October Roggli, Victor L., Robin T. Vollmer, Kelly J. Environmental Medicine, 58:670–677, 30, 2003. Butnor, and Thomas A. Sporn. ‘‘Tremolite 2001. U.S. Geological Survey (USGS). ‘‘Preliminary and Mesothelioma,’’ Annals of Selikoff, Irving J., E. Cuyler Hammond, and Compilation of Descriptive Occupational Hygiene, 46(5):447–453, Herbert Seidman. ‘‘Mortality Experience of Geoenvironmental Mineral Deposit 2002. Insulation Workers in the United States Models,’’ Open-file Report 95–831, 1995. Rooker, Stephen J., Nicholas P. Vaughan, and and Canada, 1943–1976,’’ Annals New U.S. Geological Survey (USGS). Robert L. Jean M. Le Guen. ‘‘On the Visibility of York Academy of Sciences, pp. 91–116, Virta, ‘‘Talc and Pyrophyllite,’’ U.S. Fibers by Phase Contrast Microscopy,’’ 1979. Geological Survey Minerals Yearbook, American Industrial Hygiene Association Snyder, J.G., R.L. Virta, and J.M. Segreti. 2002. Journal, 43:505–515, July 1982. (1219– ‘‘Evaluation of the Phase Contrast U.S. Geological Survey (USGS). Robert L. AB24–COMM–29–19) Microscopy Method for the Detection of Virta, ‘‘Asbestos,’’ U.S. Geological Survey Ross, Malcom. ‘‘The ‘Asbestos’ Minerals: Fibrous and Other Elongated Mineral 2003 Mineral Commodity Summary, online Definitions, Description, Modes of Particulates by Comparison with a STEM at http://minerals.er.usgs.gov/minerals/ Formation, Physical and Chemical Technique,’’ American Industrial Hygiene pubs/commodity/asbestos/070303.pdf. Properties, and Health Risk to the Mining Association Journal, 48(5):471–477, 1987. Verma, Dave K., and Nancy E. Clark. Community,’’ Proceedings of the Workshop Solomon, A., L.M. Irwig, G.K. Sluis-Cremer, ‘‘Relationships between Phase Contrast on Asbestos: Definitions and Measurement R. Glyn Thomas, and R.S.J. du Toit. Microscopy and Transmission Electron Methods, November 1978. ‘‘Thickening of Pulmonary Interlobar Microscopy Results of Samples from Rossiter, Charles E., Leonard J. Bristol, Paul Fissures: Exposure-Response Relationship Occupational Exposure to Airborne H. Cartier, John G. Gilson, T. Roger in Crocidolite and Amosite Miners,’’ Chrysotile Asbestos,’’ American Industrial Grainger, Gerald K. Sluis-Cremer, and J. British Journal of Industrial Medicine, Hygiene Association Journal, 56:866–873, Corbett McDonald. ‘‘Radiographic Changes 36:195–198, 1979. 1995. in Chrysotile Asbestos Mine and Mill Steenland, Kyle, Dana Loomis, Carl Shy, and Wang, Xiao-Rong, Eiji Yano, Mianzheng Workers of Quebec,’’ Archives of Neal Simonsen. ‘‘Review of Occupational Wang, Zhiming Wang, and David C. Environmental Health, 24:388–400, June 1972. Carcinogens,’’ American Journal of Christiani. ‘‘Pulmonary Function in Long- Rubino, G.F., M. Newhouse, R. Murray, G. Industrial Medicine, 29:474–490, 1996. Term Asbestos Workers in China,’’ Journal Scansetti, G. Piolatto, and G. Aresini. Steenland, Kyle, Carol Burnett, Nina Lalich, of Occupational and Environmental ‘‘Radiologic Changes after Cessation of Elizabeth Ward, and Joseph Hurrell. Health, 43(7)623–629, July 2001. Exposure among Chrysotile Asbestos ‘‘Dying for Work: The Magnitude of U.S. Wagner, J.C., G. Berry, J.W. Skidmore, and V. Miners in Italy,’’ Annals New York Mortality from Selected Causes of Death Timbrell. ‘‘The Effects of the Inhalation of Academy of Sciences, pp. 157–161, 1979. Associated with Occupation,’’ American Asbestos in Rats,’’ British Journal of Rubino, G.F., G. Piolatto, M.L. Newhouse, G. Journal of Industrial Medicine, 43:461–482, Cancer, 29:252–269, 1974. Scansetti, G.A. Aresini, and R. Murray. 2003. Wagner, J.C., G. Berry, J.W. Skidmore, and ‘‘Mortality of Chrysotile Asbestos Workers Stewart, I.M., and R.J. Lee. Considerations in F.D. Pooley. ‘‘The Comparative Effects of at the Balangero Mine, Northern Italy,’’ the Regulation of Actinolite, Tremolite and Three Chrysotiles by Injection and British Journal of Industrial Medicine, Anthophyllite, Society for Mining, Inhalation in Rats,’’ In: Biological Effects of 36:187–194, 1979. Metallurgy and Exploration, Inc., 1992. Mineral Fibres, J.C. Wagner (Editor-in- Rudd, Robin M. ‘‘New Developments in Suzuki, Yasunosuke, and Steven R. Yuen. Chief), IARC Scientific Publications No. 30 Asbestos-Related Pleural Disease,’’ Thorax, ‘‘Asbestos Fibers Contributing to the (2 volumes), pp. 363–372, 1980. 51:210–216, 1996. Induction of Human Malignant Warheit, David B. (Editor). Fiber Toxicology, Sali, Davide, and Paolo Boffetta. ‘‘Kidney Mesothelioma,’’ Annals New York Academic Press, Inc., 1993. Cancer and Occupational Exposure to Academy of Sciences, 982:160–176, 2002. Webster, Ian, Bertie Goldstein, Frans Coetzee, Asbestos: A Meta-Analysis of Occupational Tweedale, Geoffrey. ‘‘Asbestos and Its Lethal and Gerhardus C.H. van Sittert. ‘‘Malignant Cohort Studies,’’ Cancer Causes and Legacy,’’ Nature Reviews/Cancer Mesothelioma Induced in Baboons by Control, 11:37–47, 2000. (Perspectives), 2:1–5, April 2002. Inhalation of Amosite Asbestos,’’ American Schlecht, Paul C., and Stanley A. Shulman. U.S. Department of Labor, Office of the Journal of Industrial Medicine, 24:659–666, ‘‘Phase Contrast Microscopy Asbestos Fiber Inspector General. Evaluation of MSHA’s 1993. Counting Performance in the Proficiency Handling of Inspections at the W.R. Grace Weill, Hans, Janet Hughes, and Carmel Analytical Testing Program,’’ American & Company Mine in Libby, Montana, Waggenspack. ‘‘Influence of Dose and Fiber Industrial Hygiene Association Journal, Report No. 2E–06–620–0002, March 22, Type on Respiratory Malignancy Risk in 56:480–489, 1995. 2001. Asbestos Cement Manufacturing,’’ Schneider, Andrew. ‘‘A P–I Special Report: U.S. Environmental Protection Agency (EPA). American Review of Respiratory Disease, Uncivil Action,’’ Seattle Post-Intelligencer, Guidance for Preventing Asbestos Disease 120:345–354, 1979. November 18–19, 1999. Among Auto Mechanics, EPA–560–OPTS– Weis, Christopher P., Aubrey K. Miller, and Schwartz, David A., Charles S. Davis, James 86–002, June 1986. Paul Peronard. ‘‘Task-based exposure A. Merchant, W. Bruce Bunn, Jeffrey R. U.S. Environmental Protection Agency (EPA). monitoring for residential exposure to Galvin, D. Scott Van Fossen, Charles S. Method for the Determination of Asbestos amphibole asbestos in Libby, Montana,’’ Dayton, and Gary W. Hunninghake. in Bulk Building Materials, EPA Report No. U.S. Environmental Protection Agency, ‘‘Longitudinal Changes in Lung Function EPA/600/R–93/116 (NTIS/PB93–218576), Paper presented at 129th Annual APHA among Asbestos-Exposed Workers,’’ July 1993. [Updates and replaces Interim Meeting, October 21–25, 2001. American Journal of Respiratory Critical version in 40 CFR 763, Subpart F, App A]. West, John B. Respiratory Physiology, The Care Medicine, 150:1243–1249, 1994. U.S. Environmental Protection Agency (EPA, Essentials (Sixth Edition), Lippincott Seidman, Herbert, Irving J. Selikoff, and E. Region 8). ‘‘Environmental News ‘‘ Williams & Wilkins: Baltimore, MD, pp. 4– Cuyler Hammond. ‘‘Short-Term Asbestos Asbestos in Libby, EPA Proposes Libby as 6 and 131–133, 2000.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00039 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 43988 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules

West, John B. Pulmonary Pathophysiology, Asbestos means chrysotile, amosite (ii) Excursion limit. No miner shall be The Essentials (Sixth Edition), Lippincott (cummingtonite-grunerite asbestos), exposed at any time to airborne Williams & Wilkins: Baltimore, MD, pp. crocidolite, anthophylite asbestos, concentrations of asbestos in excess of 82–91 and 126–137, 2003. Wylie, Ann G., Robert L. Virta, and Estelle tremolite asbestos, and actinolite 1.0 fiber per cubic centimeter of air Russek. ‘‘Characterizing and asbestos. (f/cc) as averaged over a sampling Discriminating Airborne Amphibole Fiber means a particulate form of period of 30 minutes. Cleavage Fragments and Amosite Fibers: asbestos 5 micrometers (µm) or longer (3) Measurement of airborne fiber Implications for the NIOSH Method’’, with a length-to-diameter ratio of at concentration. Fiber concentration shall American Industrial Hygiene Association least 3–to–1. be determined by phase contrast Journal, 46(4):197–201, 1985. (2) Permissible Exposure Limits microscopy using a method statistically Wylie, Ann G. ‘‘The Habit of Asbestiform equivalent to the OSHA Reference Amphiboles: Implications for the Analysis (PELs). of Bulk Samples,’’ Advances in (i) Full-shift exposure limit. A miner’s Method in OSHA’s asbestos standard Environmental Measurement Methods for personal exposure to asbestos shall not found in 29 CFR 1910.1001, appendix Asbestos, ASTM STP 1342, M.E. Beard and exceed an 8-hour time-weighted A. H.L. Rooks (editors), American Society for average, full-shift airborne * * * * * Testing and Materials (ASTM), West concentration of 0.1 fibers per cubic Conshohocken, PA, 2000. centimeter of air (f/cc). PART 71—[AMENDED] Xu, An, Hongning Zhou, Dennis Zengliang Yu, and Tom K. Hei. ‘‘Mechanisms of the (ii) Excursion limit. No miner shall be 5. The authority citation for part 71 Genotoxicity of Crocidolite Asbestos in exposed at any time to airborne would be revised to read as follows: Mammalian Cells: Implication from concentrations of asbestos in excess of Authority: 30 U.S.C. 811, 951, 957. Mutation Patterns Induced by Reactive 1.0 fiber per cubic centimeter of air Oxygen Species,’’ Environmental Health (f/cc) as averaged over a sampling 6. Section 71.701 would be amended Perspectives, 110:1003–1008, 2002. period of 30 minutes. by revising paragraphs (c) and (d) to Yano, Eiji, Zhi-Ming Wang, Xiao-Rong Wang, (3) Measurement of airborne fiber read as follows: Mian-Zheng Wang, and Ya-Jia Lan. concentration. Fiber concentration shall ‘‘Cancer Mortality among Workers Exposed § 71.701 Sampling; general requirements. be determined by phase contrast to Amphibole-Free Chrysotile Asbestos, * * * * * American Journal of Epidemiology, microscopy using a method statistically 154(6):538–542, 2001. equivalent to the OSHA Reference (c) Where concentrations of airborne Method in OSHA’s asbestos standard contaminants in excess of the applicable List of Subjects found in 29 CFR 1910.1001, appendix threshold limit values, permissible 30 CFR Parts 56 and 57 A. exposure limits, or permissible excursions are known by the operator to * * * * * Air quality, Asbestos, Chemicals, exist in a surface installation or at a Hazardous substances, Metals, Mine PART 57—[AMENDED] surface worksite, the operator shall safety and health. immediately provide necessary control 30 CFR Part 71 3. The authority citation for part 57 measures to assure compliance with would continue to read as follows: § 71.700 or § 71.702, as applicable. Air quality, Asbestos, Chemicals, Coal (d) Where the operator has reasonable mining, Hazardous substances, Mine Authority: 30 U.S.C. 811. grounds to believe that concentrations safety and health. 4. Section 57.5001 would be amended of airborne contaminants in excess of Dated: July 14, 2005. by revising paragraph (b) to read as the applicable threshold limit values, David G. Dye, follows: permissible exposure limits, or Deputy Assistant Secretary of Labor for Mine § 57.5001 Exposure limits for airborne permissible excursions exist, or are Safety and Health. contaminants. likely to exist, the operator shall For the reasons set out in the * * * * * promptly conduct appropriate air sampling tests to determine the preamble, and under the authority of the (b) Asbestos standard. (1) Definitions. concentration of any airborne Federal Mine Safety and Health Act of Asbestos is a generic term for a number contaminant which may be present and 1977, we are proposing to amend of hydrated silicates that, when crushed immediately provide the necessary chapter I of title 30 of the Code of or processed, separate into flexible control measures to assure compliance Federal Regulations as follows. fibers made up of fibrils. As used in this with § 71.700 or § 71.702, as applicable. part— PART 56—[AMENDED] 7. Section 71.702 would be revised to Asbestos means chrysotile, amosite read as follows: 1. The authority citation for part 56 (cummingtonite-grunerite asbestos), would continue to read as follows: crocidolite, anthophylite asbestos, § 71.702 Asbestos standard. Authority: 30 U.S.C. 811. tremolite asbestos, and actinolite (a) Definitions. Asbestos is a generic asbestos. 2. Section 56.5001 would be amended term for a number of hydrated silicates Fiber means a particulate form of that, when crushed or processed, by revising paragraph (b) to read as µ follows: asbestos 5 micrometers ( m) or longer separate into flexible fibers made up of with a length-to-diameter ratio of at fibrils. As used in this part— § 56.5001 Exposure limits for airborne least 3–to–1. Asbestos means chrysotile, amosite contaminants. (2) Permissible Exposure Limits (cummingtonite-grunerite asbestos), * * * * * (PELs). crocidolite, anthophylite asbestos, (b) Asbestos standard. (1) Definitions. (i) Full-shift exposure limit. A miner’s tremolite asbestos, and actinolite Asbestos is a generic term for a number personal exposure to asbestos shall not asbestos. of hydrated silicates that, when crushed exceed an 8-hour time-weighted Fiber means a particulate form of or processed, separate into flexible average, full-shift airborne asbestos 5 micrometers (µm) or longer fibers made up of fibrils. As used in this concentration of 0.1 fibers per cubic with a length-to-diameter ratio of at part— centimeter of air (f/cc). least 3–to–1.

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00040 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2 Federal Register / Vol. 70, No. 145 / Friday, July 29, 2005 / Proposed Rules 43989

(b) Permissible Exposure Limits (2) Excursion limit. No miner shall be be determined by phase contrast (PELs). (1) Full-shift exposure limit. A exposed at any time to airborne microscopy using a method statistically miner’s personal exposure to asbestos concentrations of asbestos in excess of equivalent to the OSHA Reference shall not exceed an 8-hour time- 1.0 fiber per cubic centimeter of air Method in OSHA’s asbestos standard weighted average, full-shift airborne (f/cc) as averaged over a sampling found in 29 CFR 1910.1001, appendix concentration of 0.1 fibers per cubic period of 30 minutes. A. centimeter of air (f/cc). (c) Measurement of airborne fiber [FR Doc. 05–14510 Filed 7–28–05; 8:45 am] concentration. Fiber concentration shall BILLING CODE 4510–43–P

VerDate jul<14>2003 17:55 Jul 28, 2005 Jkt 205001 PO 00000 Frm 00041 Fmt 4701 Sfmt 4702 E:\FR\FM\29JYP2.SGM 29JYP2