12/26/2018 THE MICROSCOPE • Vol. 63:2, pp 59-75 (2015) Case Number: AC 17-0694 Analysis of Vermiculite for Asbestos and Screening for Vermiculite from Libby, Montana James R. Millette,Ph.D., D-IBFES Millette Technical Consulting' Steven Compton,Ph.D. MVA Scientific Consultants' ABSTRACT (PLM);scanning electron microscopy(SEM); transmis- sion electron microscopy (TEM); X-ray diffraction There is general agreement that a negative finding (XRD);Libby, Montana;Enoree, South Carolina; Louisa using the usual bulk microscope analysis for building County Virginia; Xinjiang Province, China;Palabora, materials without any pre-treatment of the vermicu- South Africa; U.S. Environmental Protection Agency lite is not reliable. Preparation procedures involving (EPA);U.S. Geological Survey(USGS); McCrone Asso- sedimentation, grinding and total matrix reduction ciates; vermiculite attic insulation (VAI); Zonolite; with acid/base dissolution have been used to improve Zonolite attic insulation (ZAI);spray -on fireproofing- the ability to find asbestos if present in vermiculite vermiculite(SOF-V); ASTM-International; Cincinnati ores and products. This article contains information Method; Alexandria Method; Beard-Shaul Method; on most of the available methods for vermiculite analy- barium (Ba). sis based on an extensive review of published articles, government reports and other documents. The lim- INTRODUCTION ited data in the published articles concerning the ma- jor vermiculite sources in the Enoree district in South This article originated as a part of a section on Carolina; Louisa County Virginia; Palabora, South vermiculite analysis in a chapter on environmental Africa; and Xinjiang Province in China strongly sug- forensic microscopy(1). The intent was to compile and gest that commercially available non-Libby vermicu- publish information about the many methods and lite is not contaminated with amphibole asbestos to procedures used to analyze vermiculite for asbestos the extent of the vermiculite from Libby, Montana. content and to distinguish between vermiculite from Differentiating Libby vermiculite insulation from other Libby and non-Libby sources. commercial sources can be done reliably and inexpen- According to the U.S. Environmental Protection sively with a routine chemical barium test as long as Agency (EPA) vermiculite is a naturally occurring the insulation sample is not a mixture of Libby ver- mineral composed of shiny flakes resembling mica miculite and other materials. A qualitative transmis- (2). When heated to a high temperature, flakes of ver- sion electron microscopy(TEM) analysis of a filtration miculite expand into accordion-like books as much of the fibers suspended in water from a sample of ver- as eight to 30 times their original size (Figures 1-2). miculite attic insulation (VAI) that was prepared us- The expanded vermiculite is a lightweight,fire-resis- ing the sedimentation procedure appears to be a reli- tant and odorless material. Sizes of vermiculite par- able method of confirming Libby vermiculite. ticles range from very fine to large (coarse) pieces Keywords: vermiculite; asbestos; tremolite; nearly an inch long and may be observed as both chrysotile; amphibole; richterite; winchite; mesothe- single flakes and books (Table 1)(3). The expanded lioma, light microscopy; polarized light microscopy product is commonly used as insulation, in building '220 Cricket Walk SW, Lilburn, GA 30047; jim millettetech.com 59 23300 Breckinridge Boulevard, Suite 400, Duluth, GA 30096; [email protected] EXHIBIT G BNSF SUPPL. AUTH IN OPP. MSJ RE STRICT LIABILITY Figure 1. Expanded vermiculite from Libby, MT. The inch ruler is Figure 2. A dose-up image shows the accordion feature of shown for scale. expanded vermiculite from Libby, MT. Table 1. Typical Sizes, Densities and Names of Expanded Vermiculite Sizes Densities Grades or Sizes KG/ LB/ U.S. MM IN N.A. CU M CU FT System International 16 5/8 Down 56-72 3.5-4.5 N.A. Premium (6) 8 5/16 Down 64-85 4.0-5.0 1 Large (4) 4 5/32 Down 72-90 4.5-5.5 2 Medium (3) 2 0.08 Down 75-112 4.7-7.0 3 Fine (2) 1 0.04 Down 80-144 5.0-9.0 4 Super fine (1) 0.5 0.02 Down 90-160 5.6-10.0 5 Micron (0) Note: These sizes and values are given for general information purposes only. All manufacturers do not necessarily produce all these grades. N A — not applicable Source www.vermiculite.net products and as a soil amendment. the U.S. from 1923 to 1990. Uses of the expanded ver- In November 1978,a commercial user of vermicu- miculite from Libby commercially known as Zonolite lite from the Libby mine reported to the EPA and (Figure 3), included insulation for attics and walls Occupational Safety and Health Administration spray-applied fireproofing such as Monokote, and (OSHA)that the user's employees were suffering ad- certain garden products. A mortality study by the verse health effects. The user surmised that the prob- Agency for Toxic Substances and Disease Registry lems may have been related to asbestos in the ver- (ATSDR), for the 20-year period ending in 1998. miculite (4). The general public became aware of the showed that mortality in the Libby community re- concern starting in 1999, when the national media sulting from asbestosis was approximately 40-60X reported that asbestos disease among the miners, higher than expected (11). ATSDR also found that families and residents of Libby was related to the mesothelioma mortality was elevated. nearby Libby vermiculite mine (5-10). This mine wa,, A detailed sampling and analyses of amphibole- the source of more than 70% of all vermiculite sold in rich rock from the Libby (Rainy Creek) vermiculite THE MICROSCOPE 63 (2015 EXHIBIT G BNSF SUPPL. AUTH IN OPP. MSJ RE STRICT LIABILITY JAMES R. MILLETTE and STEVEN COMPTON deposit was performed by Meeker and others of the U.S. Geological Survey(USGS) (12). They found a range of amphibole compositions, determined from electron probe microanalysis and X-ray diffraction analysis. Those minerals that were found in their fibrous hab- its, in order of decreasing abundance, are winchite, richterite, tremolite, edenite, magnesio-arfvedsonite and possibly magnesioriebeckite. Two types of analytical procedures are needed for vermiculite: one to measure the concentration of as- bestos present and another to classify the vermiculite as most likely having come from Libby. A method with specific sample preparation procedures for the deter- mination of the concentration of asbestos in vermicu- lite is needed because vermiculite differs from build- ing materials that might contain asbestos. It is also necessary that the method be more sensitive than the usual 100 level often used for bulk building materials. Research has shown that Zonolite attic insulation (ZAI) with low levels of asbestos can release signifi- cant levels of asbestos fibers into the air if handled improperly (13). This is in line with the study of Addison et al., 1988 that reported: "It has been shown that as little as 0.00100 of asbestos in loose clay soil can produce around 0.1 fibre per ml (0.1 fibers/cc) of asbestos in the air"(14). In addition to a method to quantitate the concen- tration of asbestos in a vermiculite sample, there is a need for an inexpensive, scientifically valid method Photo by Wiliam M Ewing to classify vermiculite as being consistent or incon- Figure 3. A bag of Zonolite attic insulation found in an attic. sistent with coming from the Libby mine. While the EPA report of 2000(15) stated that previous geological studies had established that asbestiform minerals Idaho and North Carolina. Specifically, the positive were present at two non-Libby commercial vermicu- samples came from vermiculite deposits in the Gold lite mines located in the Enoree district ofSC and one Hill district in Latah County ID; the Converse County mine in Louisa County, VA, Gunter et al., 2005 (16) WY deposit; the Addie district in Jackson County, NC; stated that the major vermiculite sources in the Enoree and two Colorado vermiculite districts, the Gem Park district, Palabora mine in South Africa and Xinjiang Complex and Powderhorn district in Gunnison Province in China do not appear to contain signifi- County. However, none of these deposits were consid- cant amounts of asbestos when compared to the Libby ered to be a significant source of commercially used ore. An EPA document reported that amphibole types vermiculite. found at Libby are not known to be found in vermicu- lite from the domestic vermiculite insulation mine EARLY ANALYSIS METHODS OF ASBESTOS IN source in Louisa County VA (17). VERMICULITE In 2005, the USGS surveyed 101 vermiculite ore samples from their archives (18). During analyses In the 1950s, Bassett used XRD and optical mi- using scanning electron microscopy(SEM), energy dis- croscopy to identify asbestos that occurred in many persive X-ray elemental spectroscopy (EDS) and thin (approximately 1 inch), white asbestos veins that X-ray diffraction(XRD) methods, significant levels of cut through the pyroxenite, when he characterized fibrous amphiboles — including winchite, richterite, the vermiculite deposit in Libby (19). tremolite, actinolite and/or riebeckite — were found In the 1970s, W.R. Grace & Company used XRD in the vermiculite deposits in Colorado, Wyoming, and polarized light microscopy (PLM) to analyze 61 EXHIBIT G BNSF SUPPL. AUTH IN OPP. MSJ RE STRICT LIABILITY mensuLy sensitises us icy Jan. 1:1, L976 Vermiculites and Tres. .tes . Optical Properties X-ray Main Peaks Mineral fine Pleochroise Densitt(dec) d (hkl) Stott te 1.569 1.609 x cy • x 2.8 - 3.4 10.1 (001). 3.37(003) x • light brown y ■ 2 • green brown Mydrobiotite 1.545 1.582 x .ey a • 2.5 - 2.8 12.4 (002). 3.53 (007) i • light brown yossmoderate brown Veratettlite 1.525 -1./61 1.545-1.58i z da ■ z 2.2 - 2.5 14.2 (002).