This paper was submitted to the ASTM Impact of Standards Paper Contest, part of ASTM’s centennial commemorations in 1998. Throughout this year, meritorious papers such as this one have been published. The winning papers were ASTM STANDARDS presented in the Feb. 1999 issue of SN. HELP DEFINE AND by Ramani Narayan

Ramani Narayan is professor of chemical and biochemical GROW A NEW engineering, Michigan State University, and chairman of ASTM Subcommittee D20.96 on Environmentally Degrad­ BIODEGRADABLE able , part of Commit­ tee D-20 on Plastics. PLASTICS INDUSTRY by Charles A. Pettigrew ntroduction nnnnnnnnnnnnnnnnnnnnnnnnn emerging technology areas such as degradable Charles A. Pettigrew is a For 100 years ASTM has provided the mecha­ plastics. senior scientist with the nism by which industry, government, and Procter & Gamble Company, academia come together to develop consen­ Background and former chairman of the sus standards. Through these standards, in­ Emerging societal concerns and a growing ASTM Institute for Standards Idustry and governments (and their regulatory environmental awareness throughout the world Research (ISR) Degradable agencies) can operate in a clear, safe, and effective triggered the search for new materials and Polymers Research Program. manner for the benefit of the general public. The processes that enhance the environmental quality ASTM process has continuously evolved over of products. Companies throughout the world these 100 years to provide state-of-the-art, scientif­ have or are initiating the design and engineering of ically credible standards that are used throughout new products with holistic environmental evalua­ the world. It was, therefore, inevitable that when tions beginning with the acquisition of raw mate­ industry introduced degradable and recycled plas­ rials, continuing through product use/, and tics in response to the new environmental and sus­ ending with disposal. Sustainable development tainable development drivers, they turned to and eco-efficiency are terms that have the atten­ ASTM to help set the standards in this area. tion of major international companies. In this con­ In this paper, we showcase the important role text, biodegradability and recyclability have be­ ASTM standards played in helping define and come important considerations in the design of grow a new biodegradable plastics industry. The new products. standards helped overcome the confusion and Designing alterna­ misunderstandings in this new area. They provid­ tives and ensuring that they end up in an appro­ ed a level, well-defined field whereby companies priate disposal system can enhance the environ­ could introduce new degradable products, gov­ mental quality of many products. For example, ernmental agencies could monitor and confirm composting is an environmentally sound ap­ degradability claims, and consumers could safely proach that recycles biodegradable into use and dispose of the products with a clear un­ useful products and minimizes the amount of derstanding of the environmental benefits of waste disposed in . Composting bi­ degradable products. This paper also demon­ odegradable polymers and paper waste along strates the synergistic value and utility of ASTM’s with other compostable materials like yard, food, Institute for Standards Research (ISR) in helping and agricultural generates high quality soil perform the necessary R&D to write standards in amendment products. amended soil

36 ASTM STANDARDIZATION NEWS, DECEMBER 1999 Table 1. Environmentally Degradable Plastics Standards

COMPOSTING ENVIRONMENT 1. Standard Test Method for Determining the Aerobic of Materials in the Presence of Municipal Sludge [D 5209] 2. Standard Test Method for Determining the Aerobic Biodegradation of Plastic Materials Under Controlled Composting Conditions [D 5338] 3. Standard Practice for Exposing Plastics to a Simulated Compost Environ­ ment [D 5509] 4. Standard Practice for Exposing Plastics to a Simulated Compost Environ­ ment Using an Externally Heated Reactor [D 5512] 5. Standard Test Method for Determining Weight Loss from Plastic Materials Exposed to a Simulated (MSW) Aerobic Compost En­ vironment [D 6003] 6. Standard Test Method for Determining the Aerobic Biodegradation in Soil of Plastic Materials or Residual Plastic Materials After Composting [D 5988] 7. Guide to Assess the Compostability of Environmentally Degradable Plastics [D 6002]—ISR Program 8. Standard Test Method for Determining Weight Loss from Plastic Materials Exposed to a Simulated Municipal Solid-Waste (MSW) Aerobic Compost En­ vironment [D 6003] 9. Standard Test for Determining Aerobic Biodegradation of Radiolabeled Plas­ tic Materials in Compost Environment [D 6340]—ISR Program 10. Standard Test Method for Determining Aerobic Degradation of Plastic Mate­ rials in a Full Scale Composting Environment [New Standard, in Committee Ballot]—ISR Program 11. Specifications for Compostable Plastics [D 6400]—ISR Program 12. Standard Practice for Preparing Residual Solids Obtained After Biodegrad­ ability Standard Methods for Toxicity and Compost Quality Testing [D 5951]—Fate & Effect Testing creates the beneficial effects of increasing soil or­ 13. Standard Practice for Water Extraction of Residual Solids from Degraded ganic carbon, increasing water and nutrient reten­ Plastics for Toxicity Testing [D 5152]—Fate & Effect Testing tion, reducing chemical inputs, and suppressing /PROCESSES plant disease. The composting infrastructure, 14. Standard Test Method for Determining the Aerobic Biodegradation of Plastic which is a key consideration in the ultimate dis­ Materials or Residual Plastic Materials After Composting in Contact with Soil posal of biodegradable polymers, is growing in [D 5988] North America and Europe. In the United States, 15. Standard Test Method for Assessing the Aerobic Biodegradation of Plastic close to 3,000 facilities compost yard waste, about Materials in an Activated-Sludge-Wastewater-Treatment System [D 5271] 150 compost sludge, 30 compost food and food 16. Standard Test Method for Determining the Anaerobic Biodegradation of Plas­ processing waste, and 20 compost . tic Materials in the Presence of Municipal Sewage Sludge [D 5210] In particular, yard waste composting facilities have 17. Standard Test Method for Determining Anaerobic Biodegradation of Plastic shown dramatic growth; since 1988 an average of Materials Under High-Solids Anaerobic Digestion Conditions [D 5511] 470 new yard waste composting facilities have 18. Standard Test Method for Determining Anaerobic Biodegradation of Plastic opened each year. Figure 1 (next page) conceptu­ Materials Under Accelerated Conditions [D 5526] ally shows a cradle-to-grave closed loop of design, 19. Standard Practice for Exposing Plastics To a Simulated Landfill Environment use, disposal, and re-use of annually renewable [D 5525] resources. OTHER Another major area of concern is marine plas­ 20. Standard Practice for Weathering of Plastics Under Marine Floating Exposure tics (single-use disposable plastics used in ships, [D 5437] plastic fishing nets and other similar items). The In­ 21. Standard Test Method for Determining the Aerobic Biodegradability of ternational MARPOL treaty (the U.S. is a signatory Degradable Plastics By Specific Microorganisms [D 5247] to the treaty along with other large and small coun­ 22. Standard Practice for Heat Aging of Oxidatively Degradable Plastics [D 5510] tries) prohibits the dumping of non-degradable 23. Standard Test Method for Determining Hydrolytic Degradation of Plastic Ma­ plastics in the sea, but degradable plastics that terials in an Aqueous Solution [D 6118] have the degradability attributes of paper could be PHOTODEGRADATION ENVIRONMENT an acceptable proposition. For example, plastic 24. Practice for Determining Degradation End Point in Degradable Polyolefins Us­ ring connectors that hold cans and bottles were ing a Tensile Test [D 3826] causing the deaths of marine animals which result­ 25. Practice for Operating Xenon Arc-Type Exposure Apparatus with Water for Ex­ ed in U.S. Public Law 100-56. U.S. Public Law posure of Photodegradable Plastics [D 5071] 100-56 requires degradable ring carriers for bottles 26. Practice for Operating Fluorescent UV and Condensation Apparatus for Ex­ and cans. posure of Photodegradable Plastics [D 5208]

ASTM STANDARDIZATION NEWS, DECEMBER 1999 37 A Challenge/Opportunity claims of biodegradable plastics, and the use of As the industry began implementing ap­ the terms biodegradable and recyclable. proaches to design biodegradable materials and Thus, it became increasingly clear that stan­ products, questions about the practicality, efficacy, dard test methods and protocols were sorely need­ and the effects of such products on the environ­ ed to establish and quantify the degradability and ment were raised. The U.S. Federal Trade Com­ biodegradability of polymers, and to confirm the mission (FTC), a group of state attorneys general, benign nature of the breakdown products. In order state legislatures, and the U.S. Congress became to ensure societal, regulatory, and market accept­ very concerned about the various degradability ance of biodegradable polymers, the ultimate and environmental claims being made, especially biodegradability of these materials needed to be as they related to existing demonstrated in appropriate waste management practices. Verification of degradability claims and infrastructures (like composting where biodegra­ environmental fate and effects of the new degrad­ dation can occur). Federal and state governments able products using acceptable well-defined test­ looked to their Environmental Protection Agencies ing protocols were lacking. to set the standards to regulate this nascent indus­ The plastics industry failed to take advantage try. The EPAs, in turn, looked to industry to provide of this opportunity at the beginning by introducing well-defined standards and measurements that starch filled (6 to 15 percent) polyolefins that were could be used to regulate the industry. claimed to be biodegradable materials. At best, these materials only disintegrated and did not Standards Development for completely biodegrade. The introduction of these Environmentally Degradable Plastics materials resulted in a number of regulatory ac­ It was in this confused and vexing regulatory tions. Eleven states enacted environmental mar­ climate that ASTM Committee D-20 on Plastics keting claim laws. A task force of several state at­ undertook the development of standards in the torneys general issued recommendations (Green area of degradable plastics. ASTM’s proven, cen­ Report I and II) on advertising related to products tury old, voluntary consensus process involving a and environmental attributes. Between October balanced participation of government, industry, 1990 and June 1992, 48 separate actions were and academia was well suited to bring order and taken for misleading or deceitful environmental understanding in this new area. advertising; the highest number of actions were on Committee D-20 formed Subcommittee

CORN

Figure 1. CO2 Sustainable Design, Use, SOIL Disposal, and HUMUS AGRICULTURAL Reuse of FEEDSTOCKS Resources

COMPOST FACILITY PROCESSING

RESTAURANT POLYMER RESIN WASTE FAST FOOD PACKAGING FAST FOOD PACKAGE RESTAURANT CONVERTER

38 ASTM STANDARDIZATION NEWS, DECEMBER 1999 Table 2. ASTM & ISO Definitions on D20.96 on Environmentally Degradable Plastics Environmentally Degradable Plastics to address the issue of standards for degradable polymers. The scope of the subcommittee was the degradable plastic, n—a plastic designed to undergo a significant change promotion of knowledge, and the development of in its chemical structure under specific environmental conditions standards (classifications, guides, practices, test resulting in a loss of some properties that may vary as measured by methods, terminologies, and specifications) for standard test methods appropriate to the plastic and the application in plastics that are intended to environmentally de­ a period of time that determines its classification. grade. Over 170 members representing a broad , n—a degradable plastic in which the degradation spectrum of interests ranging from producers, con­ results from the action of naturally-occurring micro-organisms such as verters, users, consumers, and general interest bacteria, fungi and algae. joined the subcommittee. Industry, government, photodegradable plastic, n—a degradable plastic in which the academia, and national laboratories were repre­ degradation results from the action of natural daylight. sented on the subcommittee. Interestingly, the oxidatively degradable plastic, n—a degradable plastic in which the large majority of the members joining were new to degradation results from oxidation. ASTM and its consensus process. Thus the ASTM hydrolytically degradable plastic, n—a degradable plastic in which the process was, once again, called upon to provide degradation results from hydrolysis. the framework to bring order and understanding compostable plastic, n—a plastic that undergoes degradation by in the form of standards to yet another emerging biological processes during composting to yield carbon dioxide, water, industry. inorganic compounds, and biomass at a rate consistent with other Recognizing the complexity and diversity of known, compostable materials and leaves no visually distinguishable or the standards development activity in this area, a toxic residue. modular standards development protocol was adopted. This is exemplified in Figure 2 (next page) and addresses: mung), and ISO standards closely following the • The environment to which plastic will be ex­ ASTM standards with only minor variations. The posed (simulating a real-world disposal sys­ majority of the standards address the composting tem or environment); disposal environment, given the importance of • The test method to ensure degradability (me­ composting as an ecologically sound disposal chanical and chemical property loss) and method that generates useful soil amendment biodegradability (microbial assimilation/de­ products, important for sustainable agricultural gradation); practices. • The fate and effects of the degraded products; and ASTM Institute for Standards Research • Classification based on intended application. Degradable Polymers Research Program The subcommittee is divided into sections to As Subcommittee D20.96 started writing address these and other aspects of degradability. standards in this new degradable polymers area, it the sections under D20.96 are: became increasingly clear that a certain amount • Biodegradable (D20.96.01); of research needed to be conducted before good • Photodegradable (D20.96.02); credible standards could be written. Through the • Chemically degradable—hydrolytic and ox­ ASTM Institute for Standards Research, Subcom­ idative (D20.96.03); mittee D20.96 instituted the Degradable Polymers • Environmental fate (D20.96.04); Research Program to provide the basis for scientif­ • Terminology (D20.96.05); and ic substantiation of disposability statements for • Classification and marking (D20.96.06). degradable polymeric materials in full scale dis­ Using the protocol described in Figure 2 (next posal systems. The goal was to determine the be­ page), the subcommittee has, to date, 26 ap­ havior of degradable polymeric materials in real proved standards on the books. These standards disposal systems, and how that correlates with cover various photo and bio environments that ASTM and other laboratory tests in order to assure plastics may be exposed to, and methods to quan­ that such materials are safe for disposal and effec­ tify the degradability. Table 1 (page 37) lists the de­ tively degraded. A more important goal was to veloped standards. Table 2 (above) lists the defini­ write standards based on the results of the research tions crafted by the subcommittee. These defini­ conducted. Composting was selected as the first tions are now International Organization for Stan­ disposal/waste management system for study. As dardization (ISO) standards as well. The standards discussed earlier, composting is an important measure biodegradability under different environ­ waste disposal option. Furthermore, the Federal mental/disposal conditions including composting, Trade Commission (FTC) and state attorneys gen­ soil, marine, wastewater treatment, and anaerobic eral found the greatest number of problems were digestion. The original standards activity was start­ with compostability claims. ed in ASTM with CEN (European Committee for The Degradable Polymers Research Program Standardization), DIN (Deutsches Institut für Nor- was funded by industry, including some large

ASTM STANDARDIZATION NEWS, DECEMBER 1999 39 multinational companies, government agencies, materials, including synthetic materials and poly­ and trade/consumer organizations as shown in mers derived from natural resources using the Table 3 (next page). This testifies to the importance tiered testing strategy, including laboratory-, pilot-, of this new environmentally degradable polymer and full-scale studies. The quantitative data gener­ materials area. It is also testimony to the vision and ated in these studies formed the basis for the rec­ creativity of ASTM in making ISR a forum that fa­ ommendations that the ACDP provided to the cilitates such diverse interests to come together degradable polymer industry. These recommen­ and conduct R&D that would help in writing dations focused on the usefulness of the tiered test­ good, technically sound standards. ing strategy, drawing upon the results with specif­ Experimentally determining the fate of a poly­ ic polymeric materials as case studies. The ACDP, meric material during composting involved deter­ in conjunction with the ASTM Subcommittee mining first the physical and chemical stability of D20.96 prepared standard D 6002, Guide to As­ the materials and second, whether the materials sess the Compostability of Environmentally De­ had the potential to be completely biodegraded. gradable Plastics. This guide provides a systematic This process started with screening level evalua­ approach to determining the compostability of a tions that were followed by confirmatory studies plastic or any other material that could enter the conducted in pilot, and full-scale composting sys­ municipal solid waste stream. The scheme is cost tems. Similar approaches were used to understand effective because information is generated from the fate of a material in compost amended soil. In lower-level, less expensive tests to higher-level, both cases there was a need to determine if per­ more expensive ones. The strategy covers the sistent residues or intermediates were produced. three aspects of compostability: biodegradability, In order to generate these data, the Advisory Com­ ecotoxicity, and composting processability (the mittee on Degradable Polymers Program (ACDP) mechanical behavior of the material in a compost (see Table 3, next page) and ASTM Subcommittee process). A detailed report on the composting trial D20.96 developed a tiered testing strategy for as­ has been issued. Several other important test sessing the compostability of polymeric materials. methods like the testing with radiolabeled materi­ The ACDP tested a broad range of degradable als, test methods for performing pilot and full-scale

FIGURE 2. D20.96 Standards PHOTO BIO TEST MATERIAL Development CONTROLS “X” Compost Landfill Soil Protocol Fluorescent UV

Terrestrial Aerobic Xenon Arc TEST ENVIRONMENTS Anaerobic Aquatic

Accelerated Natural Marine Freshwater Aquatic TEST METHOD ENVIRONMENTAL FATE Terrestrial MECHANICAL PROPERTY CHEMICAL PROPERTY BIOLOGICAL PROPERTY Reduction in Molecular Weight (Red in MW); Loss of tensile strength Dilute Solution Viscosity (Dil. Sol. Vis.) CO2/CH4 evolution Tumbling friability for PS Functional group changes Carbon balance Aerobic vs. anareobic

% degradation of test sample CLASSIFICATION (+ve & -ve controls)

APPLICATION SUITABILITY OR APPLICABILITY IN MARKING SCHEME FOR DEGRADABLE PLASTICS TARGETED DISPOSAL SYSTEMS OR ENVIRONMENTS

40 ASTM STANDARDIZATION NEWS, DECEMBER 1999 Table 3. Sponsor Members of Advisory composting, and specifications for compostable Committee on Degradable Polymers Program plastics evolved from the program, and are under (ACDP) various stages of balloting. Cargill Impact of the Environmentally Degradable Plastic Standards Dow Chemical The technical standards, definitions, and test DuPont methods that have emerged from the ASTM and Eastman Chemical ACDP biodegradable polymer programs have had important commercial and societal impacts. As Ecochem discussed earlier, the biodegradable polymer in­ US Army Natick RD&E dustry suffered a severe setback a decade ago KimberlyClark when the first generation polyolefin-starch materi­ als did not degrade as claimed. Through the sem­ Mobil Chemical inal work and technical leadership of ASTM Sub­ Novamont committee D20.96 and its ISR-ACDP program, Novon International the degradable plastics industry now has the tools it needs to ensure the credibility of claims for cur­ Procter & Gamble rent and future generations of degradable plastic Zeneca Bioproducts products. National Com Growers Association The ASTM and ACDP biodegradable poly­ mer programs have generated information on the Association of the Nonwovens Fabrics Industry (INDA) of a benchmark set of materials that have been used by industry in comparing the per­ formance of many newly developed materials. Degradable Polyethylene and Us­ For example, the ACDP reported that the results ing a Tensile Test, as the test methods to use to ver­ obtained for the same material at each tier within ify and confirm degradability. The state of Wiscon­ the ASTM standard guide shows that for all mate­ sin’s Department of Transportation in its procure­ rials compared, without exception, the degrada­ ment guidelines for erosion mat stakes cites ASTM tion results obtained in a higher-level test equaled D 5338 as its measure of biodegradability. That or exceeded those obtained in a lower-level test. ASTM standard also forms the basis for the new This means that the laboratory scale ASTM D standard D 6002, Guide for Assessing the Com­ 5338, Test Method for Determining Aerobic postability of Environmentally Degradable Plastics. Biodegradation of Plastic Materials Under Con­ The presence and acceptability of the standards trolled Composting Conditions, was more conser­ are attracting many companies to develop degrad­ vative than the pilot-scale tests that, in turn, were able plastics for a variety of applications. more conservative than the full-scale tests. These In the United States, multinational companies observations have important ramifications with re­ such as Cargill-Dow (a joint venture of Cargill and gard to environmental claims and the cost of gen­ Dow Chemical), Eastman Chemical, DuPont, erating data to support those claims. On the basis Monsanto, Union Carbide, and National Starch of the ASTM and ACDP program results, a materi­ and Chemical are commercializing biodegrad­ al developer is able to generate a reliable and able plastics. In addition, there are a number of credible data package based upon relatively rapid small- and medium-size companies that are also laboratory- and pilot-scale tests that would be ac­ actively pursuing commercialization of degrad­ cepted by the governmental regulatory agencies able plastics. The 170-member strength of sub­ and the general consumer. committee D20.96 is indicative of this strong ac­ Thus, from a state of confusion, misunder­ tivity in the area of degradable plastics. standings, and legal actions by the attorneys’ gen­ On the international level, the ASTM stan­ eral task force and the FTC, the degradable plastics dards have led the way for the CEN, DIN, and ISO industry has begun to successfully introduce standards. Asian countries such as Japan, Taiwan, degradable plastics in the marketplace based on and Korea are using the ASTM standards as the ba­ the technical strength and clarity of the developed sis for developing and using biodegradable plas­ ASTM standards and the ISR-ACDP program. Ex­ tics. Some of the major international companies amples of this success can be found in U.S. Public involved in biodegradable plastics are Bayer and Law 100-56, which requires degradable ring car­ BASF (Germany), Novamont (Italy), Showa High riers for bottles and cans that cites ASTM D 5208, Polymer, Mitsui Toatsu, and Shimadzu (Japan). Standard Practice for Operating Fluorescent Ultra­ These companies and their new biodegrad­ violet (UV) and Condensation Apparatus for Expo­ able thermoplastic technologies target a broad list sure of Photodegradable Plastics, and D 3826, of applications such as: Practice for Determining Degradation End Point in • Starch-based loose fill and rigid foam pack-

ASTM STANDARDIZATION NEWS, DECEMBER 1999 41 Standard Specification for aging; tinue to grow as the composting infra­ • Packaging materials for single- or structure expands. Centralized yard Compostable Plastics limited-use disposable composting facilities have and film applications; grown from 651 in 1988 to 2,980 in A Milestone Achieved • Disposable nonwovens and hy­ 1992 and continues to grow. This dra­ giene products; matic increase in the number of com­ A major milestone was met with the ap­ • Consumer goods—items such as posting facilities is complemented by proval of the Specification for Com­ cups, plates, cutlery, containers, increased throughput by existing facili­ postable Plastics (D 6400). This standard egg cartons, combs, razor han­ ties, resulting in further demand for establishes criteria (specifications) for dles, toys, etc.; compostable bags. plastics and products made from plastics • Coatings for paper and film; and Twenty states now mandate to be labeled compostable. It establishes • Marine plastics—fishing lines, composting of lawn and leaf waste, whether plastics and products made from nets, pots etc., plastics used in and many more will follow this trend. plastics will compost satisfactorily, includ­ ships (MARPOL treaty). in addition, because of their bio­ ing biodegrading at a rate comparable to Film applications in single-use dis­ degradability, state regulations increas­ known compostable materials. This speci­ posal packaging and select non-pack­ ingly require the use of paper bags in­ fication is comparable to what is being de­ aging disposal applications represent stead of plastic. Biodegradable plastic veloped by the European Committee for the best opportunity for biodegradable bags are lighter, and have better Standardization (CEN) in Europe today, plastics. The film applications that are strength and water resistance than pa­ and in harmony with the Deutsches Institut the most promising and having imme­ per. In the future, it is likely that the für Normung (DIN) standard, moving the in­ diate potential are in: composting of other waste streams, dustry closer to global standards. The • Lawn and leaf compost bags; such as food waste, will be required. specification is based on and references • Agricultural film; and This will also increase the size of the three other D20.96 standard documents • Retail carry-out packaging bags market for biodegradable plastics. for the testing and identification of plastics (tee-shirt and other merchandise that will biodegrade and compost satisfac­ bags, garment bags, grocery bags, Conclusions torily. They are: etc.). ASTM standards have helped de­ D 6002, Guide for Assessing the Com­ One of the most promising appli­ fine and grow a new degradable plas­ postability of Environmentally Degradable cations for the use of biodegradable tics industry—that was not accepted Plastics—Outlines recommended proce­ plastics is lawn and leaf waste compost by the consumer and was looked upon dures and a general approach to establish bags. Steady growth in the yard waste­ warily by regulators—to a strong, thriv­ the compostability of plastics. It provides a composting infrastructure in recent ing industry attracting large multina­ three-tiered criteria-based approach that years has created a renewed demand tional companies commercializing includes rapid screening tests, laboratory for biodegradable compost bags. The biodegradable plastics worldwide. and pilot scale composting assessment, EPA reports that 20 percent of the 32.8 This paper showcases the impact of and field/full scale assessment. million metric tons of yard trimmings not only the ASTM standards, but D 5338, Test Method for Determining generated in 1993 were delivered to ASTM itself and its ability to continu­ Aerobic Biodegradation of Plastic Materi­ central composting facilities. This ously evolve to respond to current als Under Controlled Composting Condi­ amounts to approximately 6.6 million needs with programs such as ISR, tions—Determines the degree and rate of metric tons (14 billion lb) of yard trim­ which was so vital for the degradable aerobic biodegradation of plastic materials mings collected primarily in polyethyl­ plastics standards. on exposure to a controlled-composting ene bags, but also in kraft paper com­ Companies, researchers, and con­ environment under laboratory conditions. post bags or in bulk. Based on this sumers will continue to turn to ASTM D 6340, Test Method for Determining amount of yard trimmings, the poten­ and its team to help define and grow Aerobic Biodegradation of Radiolabeled tial annual market for compost bags is the next generation of products, tech­ Plastic Materials in an Aqueous or Com­ 450 million 30-gallon (114 L) bags (as­ nologies, and services as the degrad­ post Environment—Determines the rate suming that one 30-gallon compost able plastics industry has. and degree of biological oxidation of car­ bag holds on average 30-33 pounds bon in plastic materials when placed in a (13.5 to 15 kg) of yard waste). This Acknowledgement composting environment containing simu­ translates to 56 million pounds (25 000 The development of degradable lated municipal solid waste or an aqueous metric tons) of resin (estimating that plastics standards and its significant environment under laboratory conditions. one pound of resin yields eight 30-gal­ role in growing the degradable plastics It applies to plastics the biodegradation lon bags of 1.5 mil thickness) (1 kg of industry would not have been possible rate of which is slow and requires test pe­ resin yields 18 bags of 38 micrometre without the selfless work of members riods of as long as 365 days. thickness). It is estimated that yard of Subcommittee D20.96, the ISR Ad­ These documents are based on the waste composting grew to 20 billion lb visory Committee on Degradable results of the work of Subcommittee (9 million metric tons) in 1994, provid­ Polymers Program, and the superb staff D20.96 on Environmentally Degradable ing an 83 million lb (38,000 metric of ASTM and ISR, particularly its Staff Plastics and several years of research con­ ton) market potential for compost bags. Managers Kathie Morgan (Committee ducted by ASTM’s Institute for Standards The market for compost bags will con­ D-20) and Ann McKlindon (ISR). Research at the request of D20.96.

42 ASTM STANDARDIZATION NEWS, DECEMBER 1999