Proceedings: Third International Scientific Workshop on Biodegradable Plastics and Polymers; Osaka, Japan, Nov 9-11, 1993. Narayan R., Impact of Governmental Policies, Regulations, and Standards Activities on an Emerging Biodegradable Plastics Industry, In Biodegradable Plastics and Polymers, Eds., Y. Doi & K. Fukuda, Elsevier, New York, 1994, pg. 261

Impact of Governmental Policies, Regulations, and Standards Activities on an Emerging Biodegradable Plastics Industry

Ramani Narayan

Michigan Biotechnology Institute & Michigan State University
3900 Collins Road, Lansing, Michigan, 48910 U.S.A.

1. INTRODUCTION

New environmental regulations, societal concerns, and a growing environmental awareness throughout the world has triggered a paradigm shift in industry to develop products and processes compatible with the environment. This brings up the issue of designing materials from "Cradle to Grave" that integrates material design concepts with ultimate disposability and resource utilization and conservation.

Currently, most products are designed with little consideration to its ultimate disposability. Of particular concern, are plastics used in single-use disposable packaging, service-ware items, disposable nonwovens, coatings, marine plastics. Designing these materials to be biodegradable and ensuring that they end up in an appropriate disposal system that would utilize the biodegradability functionality is an environmental and ecologically sound approach to use and ultimate disposal of these materials. For example, composting our biodegradable plastic and paper waste along with other organic compostable materials like yard, food, and agricultural wastes creates valuable, carbon-rich compost (humic material). Compost amended soil has beneficial effects such as increasing soil organic carbon, increasing water and nutrient retention, reducing chemical inputs, and suppressing plant diseases [1]. Composting infrastructures, which is important for the use and disposal of biodegradable plastics, are growing in the U.S. and is, in part, regulatory driven.

This paper reviews the emerging biodegradable plastics industry and the impact of governmental policies and regulations on the growth of this industry. The development of ASTM Standards and other Standards related activities in this area is discussed.

2. MATERIALS DESIGN FOR THE ENVIRONMENT

As discussed earlier, most of today's materials are designed with little consideration to:

· Utilization of Resources (the starting feedstocks from which the material/product is derived from) and its impact on the environment. Issues relating to resource conservation and depletion and the potential benefits of utilizing annually renewable resources has not been a factor in material design and engineering.

· Ultimate disposability of the material/product, i.e. what happens to the product after use when it enters the waste stream.

Today, there is a paradigm shift, and industry is essaying to make changes in product design and engineering to meet requirements for ultimate disposability and address issues relating to resource conservation and utilization [2]. Thus, materials have to be designed from "Cradle to Grave". The environmental impact of each step from raw material procurement to ultimate disposability has to be factored into the design of the product (Figure 1).

Of particular concern is the disposability of single-use, disposable plastics packaging products and consumer items. This represents about 30% of the total plastic resins sold in the U.S. and totals 20 billion pounds. These plastics are strong, light-weight, inexpensive, easily processable, and energy efficient. However, it is these very attributes of strength and indestructibility that cause problems when these materials enter the waste stream. Designing these plastics to biodegrade in appropriate disposal infrastructures seems an elegant and ecologically correct solution to the disposability problem. Thus, the degradable plastics industry was born.

3. U.S BIODEGRADABLE PLASTICS INDUSTRY

As industry began implementing approaches to design environmentally benign products, questions about the practicality, efficacy, and the effects of such products on the environment were raised. The U.S. Federal Trade Commission (FTC), a group of State Attorney General's, State legislatures, and the U.S. Congress became very concerned about the various degradability and environmental claims being made, especially as it related to existing waste management practices. Verification of degradability claims and environmental fate and effects of the new degradable products using acceptable well-defined testing protocols were lacking.

The U.S biodegradable's industry fumbled at the beginning by introducing starch filled (6-15%) polyolefins as true biodegradable materials [3]. These at best were only biodisintegrable and not completely biodegradable. Data showed that only the surface starch biodegraded, leaving behind a recalcitrant polyethylene material [4, 5]. Starch entrapped within the PE matrix did not appear to be degraded.

3.1. Regulatory Actions

This resulted in a number of regulatory actions. Eleven States enacted environmental marketing claim laws . A task force of several State Attorney General's issued recommendations (Green Report I & II)on advertising related to products and environmental attributes [6]. Between October 1990 and June 1992, 48 separate actions were taken for misleading or deceitful environmental advertising. The highest number of actions were on claims of biodegradable plastics, and the use of the terms biodegradable, recyclable, ozone friendly.

The initial Green Report I was very restrictive, basically prohibiting the use of terms such as biodegradable and compostable. However, Green Report II was more accommodating and allowed for the development and introduction of true biodegradable materials. For claims relating to biodegradability, Green Report II [6] states:

"It may be appropriate to make claims about the "biodegradability" of a product when that product is disposed of in a waste management facility that is designed to take advantage of biodegradability and the product at issue will safely break down at a sufficiently rapid rate and with enough completeness when disposed of in that system to meet the standards set by any existent state or federal regulations."

Therefore, in order to ensure environmental, regulatory, and market acceptance of biodegradable plastics, the ultimate biodegradability of these materials needs to be demonstrated in appropriate waste management infrastructures (like composting or sewage treatment facilities or soil where biodegradation can occur). More importantly, the breakdown products of the biodegradation process should be non-toxic, and should not build up in the environment at a rate faster than it is being utilized by the microorganisms.

The U.S. Federal Trade Commission (FTC) guidelines states [7]:

"Unqualified degradability claims should be substantiated by evidence that the product will completely break down and return to nature, that is decompose into elements found in nature within a reasonably short period of time after consumers dispose of it in the customary way ............."

With regards to compostability claims, the FTC guidelines state:

"........ substantiated by evidence that all the materials in the product or package will break down into, or otherwise become part of, usable compost (e.g., soil-conditioning material in a safe or timely manner in an appropriate composting program or facility , or in a home compost pile or device .......")

Thus it became increasingly clear that Standards were sorely needed in this area. Standard test methods and protocols were needed to establish and quantify biodegradability of the plastics, and to confirm the benign nature of the breakdown products. It is also clear that claiming biodegradability for a product without linking it with the waste management infrastructure that the product can be sent to, does not make environmental sense and is unacceptable.

3.2. Integration of materials design with waste management infrastructure -- Designing for ultimate disposability.

Simply labeling a product biodegradable or recyclable makes little ecological sense, unless the product ends up in the appropriate infrastructure that utilizes the functionality of biodegradability or recyclability. Thus, recycling makes sense only if significant amounts of the product can be collected and sent to a recycling facility where it is recycled into another product in an economical way. Biodegradability attributes for a product make sense only if the product is collected and sent to a waste management facility where the product can undergo biodegradation. Composting, sewage and waste water treatment facilities, anaerobic digestors, and managed, biologically active landfills are waste management infrastructures where biodegradability of the waste is important. In the U.S., unfortunately, most landfills are designed to be tombs where biodegradation is inhibited. As much as 80% of the municipal solid waste (MSW) stream ends up in such landfills. Entombing the readily biodegradable organic waste component of MSW in such landfills and preserving them for posterity does not make ecological or economic sense. Figure 2 shows the compostable components of the MSW stream. The single-use disposable plastics and the coated, soiled paper (not suitable for recycling) are shown as potential compostable fractions. Thus, a significant portion of MSW can be treated by biodegradation infrastructures such as composting.

Therefore, to ensure that a product meets today's environmental criteria, integration of waste management with product design and engineering has to occur . Figure 3 captures this concept. At our Institute, the Michigan Biotechnology Institute, such an integrated material design, use, and ultimate disposability by composting is underway. MBI is currently developing corn based coatings for paper cups and sandwich wraps as replacement for current non biodegradable polyethylene and wax coatings. The new coatings have acceptable water and grease barrier properties and are compatible with both composting and paper recycling processes. Additionally, MBI is also engineering starch based moldable products that have water repellent properties, mechanical strength, good processability, and compostability, for cutlery and other applications. A demonstration program, in which these materials would be introduced into a fast-food restaurant setting, the waste collected and composted with other necessary lignocellulosic and nitrogenous wastes, is underway. The utility and value of the compost generated will be established by applying it on experimental farm land (see paper in these Proceedings entitled "Biodegradation and Composting Studies of Polymeric Materials).

4. COMPOSTING & THE ENVIRONMENT

Composting is an ecological and environmentally sound approach to transfer biodegradable waste including the new biodegradable plastics to useful soil amendment product. Composting is truly biological recycling of carbon [1]. Composting can be defined as "accelerated degradation of heterogeneous organic matter by a mixed microbial population in a moist, warm, aerobic environment under controlled conditions". Polymeric materials (plastics), when designed to be biodegradable using renewable resources (agricultural feedstock) as the major raw material component, can become part of this ecologically sound mechanism -- "Nature's Recycling System". Biodegradation of such natural materials will produce valuable compost as the major product, along with water and carbon dioxide. The CO2 produced should not contribute to an increase in greenhouse gases because it is "fixed" as part of the biological carbon cycle.

By composting our biodegradable plastic and paper waste along with the other biodegradable waste of MSW, we can generate much-needed carbon-rich soil (humic material). Compost amended soil can have beneficial effects by increasing soil organic carbon, increasing water and nutrient retention, reducing chemical inputs, and suppressing plant diseases. The problem of waste disposal could become the solution for low-input sustainable agriculture. Table 1 shows the role of composting in the waste management hierarchy of Reduce, Reuse, and Recycle (the three R's). Thus, composting counts towards source reduction and recycling.

Table 1.

Composting in Waste Management Hierarchy

COMPOSTING TYPE

WASTE MANAGEMENT HIERARCHY

Grass mulching and landscaping

Counts towards source reduction

On-site & Home composting

Counts towards source reduction

Composting of source-separated biodegradable wastes of MSW

Counts towards recycling and diversion from landfill

Mixed MSW composting

Counts towards recycling -- lower value application

4.1 Composting Infrastructure & Regulations

After many years in obscurity, composting has returned as an important and ecologically sound approach to managing waste, especially the biodegradable component of our waste stream. Close to 3,000 facilities compost yard waste, about 150 compost sludge, 30 compost food and food processing waste, and 20 compost mixed waste. Table 2 shows the dramatic growth in the number of facilities especially for yard waste composting. Since 1988, an average of 470 new yard waste composting facilities have opened each year.

Table 2.

Growth in Number of Composting Facilities

 

OPERATING COMPOSTING FACILITIES AT YEAR END

YEAR

YARD WASTE

SLUDGE

MIXED MSW WASTE

1988

651

79

--

1989

986

119

7

1990

1,407

133

13

1991

2,201

149

18

1992

2,500 (aprox.)

159

21

Source: Biocycle, U.S. Composting Council

A number of factors have contributed to the growth of composting infrastructures:

1. Nearly every State within the past five years have either established or raised recycling goals. Based on the composition of MSW, the only way to reach goals of 30, 40, or 50% recycling is to have a substantial composting element. The U.S. Environmental Protection Agency (U.S. E.P.A) and many States identify composting as a form of recycling.

2. Relative costs for disposal are much higher. The unpopularity of landfills and strict regulations governing them have pushed landfill costs sharply upward. In many parts of the country composting is becoming competitive with other waste management approaches.

3. Separation technologies have improved and contaminants can be effectively separated. Also community separation programs have had excellent participation.

4. Legislative mandates have been the biggest factor. Twenty six States plus the District of Columbia now have some kind of provision to separate and or ban yard waste from landfills. Some are outright bans, others are incentives and endorsements.

Another major incentive driving composting is that many States have instituted compost procurement policies. Thus, markets for the finished compost has been created by Government fiat. In many States, the State agencies and local governments are required to procure compost product for land maintenance activities -- highway construction, landscaping, re-cultivation, soil erosion control

5. STANDARDS DEVELOPMENT ACTIVITIES

ASTM, a voluntary, not-for-profit Standards organization created a subcommittee under its Technical Committee on Plastics (D-20) to address the issue of standards for degradable plastics. The scope of the subcommittee was "The promotion of knowledge, and the development of standards (Classification, guide, practice, test method, terminology, and specification) for plastics which are intended to environmentally degrade. Currently, there are 170 plus members on the subcommittee and they represent a broad spectrum of interests ranging from producers, users, consumers, and general interest. Industry, government, academia, and National laboratories all have representatives on the subcommittee. One does not have to be a regular paying member of ASTM to participate in the standards development activities of the subcommittee. The subcommittee is further divided in to sections to address various aspects of degradability. The sections under D-20.96 are:

· Biodegradable (D-20.96.01)

· Photodegradable (D-20.96.02)

· Chemically degradable (D-20.96.03) -- hydrolytic, & oxidative

· Environmental Fate (D-20.96.04)

· Terminology (D-20.96.05)

· Classification & Marking (D-20.96.06)

5.1. Photodegradable Standards

Two Standard Practices for exposure of photodegradable plastics to simulated test environments have gone through the "ASTM consensus process" and published as a ASTM Standard. The two are:

· Standard Practice for operating Xenon Arc Type exposure apparatus with water for exposure of photodegradable plastics (D5071-91)

· Standard Practice for operating fluorescent UV and condensation apparatus for exposure of photodegradable plastics. (D5208-91)

A Standard Practice for determining degradation end-point in degradable polyolefins using a tensile test has been published as a society standard (D3826-91). This practice determines the degradation end point (brittle point) for degradable polyethylene and polypropylene films and thin sheeting. The standard establishes loss in structural integrity of the degraded plastic material and is a valuable end-point for degradable plastics designed for litter control, and mitigating strangulation hazards posed to marine life. This method would apply to biodegradable plastics and establish loss in structural integrity i.e., biodisintegration. A round robin inter-laboratory study is being initiated to determine Precision and Bias for this test method.

Another Standard Practice for Outdoor Exposure Testing of Photodegradable Plastics has also cleared and is ready to be published as a ASTM standard.

5.2. Biodegradable Standards

Test methods to measure the intrinsic biodegradability of plastic materials designed for biodegradability have cleared society balloting and are full-fledged ASTM standards. The test method measures the percent conversion of the carbon from the designed biodegradable plastic to CO2 in a aerobic environment and CH4 (plus some CO2) in a anaerobic environment. The test material is the sole carbon source for the microorganism in the experiment. The two bio-test methods are:

· Standard Test Method for Determining the Aerobic Biodegradation of Plastic Materials in the Presence of Municipal Sewer Sludge (D5209-91).

· Standard Test Method for Determining the Anaerobic Biodegradation of Plastic Materials in the Presence of Municipal Sewer Sludge (D5210-91)

Three other bio-test methods have become ASTM Standards. They are:

· Standard test method for assessing the aerobic biodegradation of plastic materials in an activated sludge-waste water treatment system (D5271-92)

· Standard test method for determining the aerobic biodegradation of plastic materials under controlled composting conditions (D5338-93)

· Standard test method for determining the aerobic biodegradability of degradable plastics by specific microorganisms (D5247-92)

The first two simulate environments that are representative of waste management infrastructures such as composting and waste-water treatment system. The test methods permit one to quantify biodegradability in specific waste management infrastructures. While these test methods give a quantitative measure of biodegradability in such environments, parallel tests in "real world systems" need to be run to confirm and establish biodegradability. ASTM is currently developing standard practices for exposing degradable plastics to such "real systems" environments and reporting the resultant data. The specific microorganisms test method does not represent any real world waste management infrastructure but provides a standard test method to quantify biodegradability using well-defined microbial cultures commonly present in the environment.

Aquatic Biodegradability: Mitigating the hazards to marine life by designing bio and photodegradable plastics that would degrade in a marine environment is one of the targets for industry. Thus, to evaluate the biodegradability potential in a aquatic environment, Standard Practices for Exposing Plastics to a Simulated Marine and Fresh-Water Environments were developed and are now at the Society balloting stage. A Standard Test Method to quantify the amount of degradation in such environments is currently being developed and will build on the two aquatic test practices discussed. A Standard Practice for Weathering of Plastics under Marine Floating Exposure [D 5437-93]

Composting Environment: Composting is fast becoming a important waste management strategy. Biodegradable plastics that will be compostable in an appropriate composting infrastructure are being designed. As discussed earlier, a Standard Test Method for Determining the Aerobic Biodegradation of Plastic Materials under Controlled Composting Conditions has been developed. Two Standard Practices for exposing plastics to a simulated compost environment with and without an externally heated reactor have also been developed.

Soil Environment: Test Practices and Methods for determining the biodegradability potential in soil burial tests are under development.

Others: A number of other specific test methods are under various stages of development for example, a high solids anaerobic digestor system, accelerated (biologically active) landfill conditions.

5.3 Fate & Effects Testing on Biodegraded Products

One of the major issues raised in connection with degradable plastics is the fate and toxicity of the degraded products. A Standard Practice for Water Extraction of Residual Solids from Degraded Plastics for Toxicity Testing has been developed. It is a published ASTM Standard (D 5152-91) having successfully going through the ASTM consensus process. The practice is essentially a "bridging" practice to prepare samples from degraded plastics for aquatic toxicity testing using established toxicity test methods such as ASTM methods D 4229, E 1192, E 1295 or other currently accepted toxicity test methods. A round-robin inter-laboratory testing to demonstrate the utility of the existing practice is being initiated. A similar "bridging" practice for preparing degraded plastic samples for terrestrial toxicity testing is under development. In the area of composting this would extend to establishing that the compost can promote microbial and plant growth, and leave behind no persistent/recalcitrant or toxic residue.

5.4. Marking & Classification

The purpose of developing a marking scheme for degradable plastics is to identify the plastic as a degradable plastic and delineate its type i.e., photo, bio, oxidative, hydrolytic. Having such markings would promote the disposal of such plastics in appropriate waste management infrastructures such as composting or sewage treatment plants. It would also ensure that these plastics do not end up in other segregated waste streams. The marking does not certify the degradability of the plastic for which appropriate Standard Test Methods must be employed.

It is envisioned that as data are accumulated on degradable plastics using the ASTM Test Methods a classification scheme would evolve. Conceptually this would be based on the time period to achieve a specific degradation end-point.

5.5. Terminology and Definitions

ISO 472:1988 (International Standards Organization)

Degradation -- A change in the chemical structure of a plastic involving a deleterious change in properties.

Deterioration -- A permanent change in the physical properties of a plastic evidenced by impairment of these properties.

ASTM D-20.96 definitions

degradable plastic, n -- A plastic designed to undergo a significant change in its chemical structure under specific environmental conditions resulting in a loss of some properties that may vary as measured by standard test methods appropriate to the plastic and the application in a period of time that determines its classification.

biodegradable plastic, n -- A degradable plastic in which the degradation results from the action of naturally-occurring micro-organisms such as bacteria, fungi and algae.

photodegradable plastic, n -- A degradable plastic in which the degradation results from the action of natural daylight.

oxidatively degradable plastic, n -- A degradable plastic in which the degradation results from oxidation.

hydrolytically degradable plastic, n -- A degradable plastic in which the degradation results from hydrolysis.

5.6. ISR (Institute for Standards Research) Degradable Plastics Program

ASTM instituted a research program to provide the basis for scientific substantiation of disposability statements for degradable polymeric materials in full scale disposal systems. The goal was to determine the behavior of degradable polymeric materials in real disposal systems, and how that correlates with ASTM and other laboratory tests in order to assure that such materials are safe for disposal and effectively degraded. Composting was selected as the first disposal/waste management system for study. As discussed before, this was one of the criteria that the FTC and State Attorney General's deemed essential. A detailed report on the composting trials is to be issued shortly.

6. FURTHER REGULATIONS IMPACTING BIODEGRADABLE PLASTICS

In section 3 the FTC guidelines and the State Attorney General's Green Report was discussed. In section 4 regulations promoting composting was discussed. As discussed, the development of composting infrastructures would drive demand for biodegradable products.

Packaging materials have been a major target of legislative restrictions, because they represent 30% of MSW, have high visibility as litter, low in weight but high in volume. They are not recycled and non-biodegradable. Some of the legislation enacted or under consideration are as follows:

· Since January 1989, 48 States have enacted over 140 recycling law

· Twenty-seven States have banned certain packaging products from solid waste disposal facilities.

· One hundred product disposal bans exist to date, 45 enacted in 1990.

· Several States (e.g., Pennsylvania, New Jersey, Wisconsin) have passed laws specifically requiring commercial business to separate recyclables.

· At least 22 States are requiring or will require targets for packaging material reduction, reuse, recycled content, or recyclability on all retail packages.

· U.S. Public Law 100-56 requires degradable ring carriers for bottles and cans. The test method cited in it is ASTM D-5208

· The Marpol treaty prohibits the dumping of plastics into the oceans but paper is allowed.

· Minnesota law requires preferential use of degradable loose-foam packaging material upto a 10% price increase.

· Minnesota, Michigan and other States are considering a ban on non-degradable bags for composting

Biodegradable materials/plastics in concert with composting infrastructures would satisfy the legislative requirements discussed and is truly an ecological and environmentally sound approach for product design, use and disposal.

7. CONCLUSIONS

Governmental policies, regulatory drivers, and environmental consciousness bodes well for an evolving biodegradable plastics industry. Today, biodegradable products being introduced or planned to be introduced by various companies are fully biodegradable or compostable. The need to tie in the waste management infrastructure, like composting, with use of biodegradable materials is recognized and being actively pursued. Composting and other regulations favor the need to design truly biodegradable materials. ASTM standards have been developed for determining intrinsic biodegradability, biodegradability under composting conditions, biodegradability under other environmental conditions, and environmental fate of degraded products. Many more Standards are under development. FTC guidelines on the subject of biodegradability, compostability, recyclability, and other environmental claims have been issued. Detailed scientific substantiation for the biodegradability of the new products in specific waste management infrastructures such as composting is being obtained with programs like the ISR.

Thus, in today's market place there is a much greater acceptance of biodegradable products, and a better appreciation of the role of biodegradable materials in waste management. However, the problems of the early biodegradable products, still, continues to plague the nascent biodegradable materials industry. Industry needs to be careful about their biodegradability claims and work on integration with disposal infrastructures like composting. In addition, evolving ISO (International Standards Organization) Product Standards on environmental labeling, and Life Cycle Assessment (LCA) from technical committee (TC 207) will have to taken into consideration.

8. REFERENCES

1. R. Narayan, In "Science and Engineering of Composting: Design, Environmental, Microbiological and Utilization Aspects"; Eds. H. A. J. Hoitink and H.M. Keener, Renaisance Publications, Ohio, 1993

2. R. Narayan. ACS Symp. Ser., 476, 1992

3. See papers in "Degradable Materials: Perspectives, Issues, and Opportunities", S.A. Barenberg, J.L. Brash, R. Narayan, and A.E. Redpath, Eds., CRC press, FL., 1990

4. P. Barak, Y. Coquest, T.R. Halbach, and J.A.E. Molina, J. Environ. Qual., 20, 173 (1991)

5. L.R. Krupp, and W.J. Jewell Environ. Sci. Technol., 26, 193, 1991

6. W.L. Webster, "The Green Report II: Recommendations for Responsible Environmental Advertising," States Attorney-General, Office of the Attorney-General, Missouri, Jefferson City, MO, May 1991

7. Guides for the use of environmental marketing claims, U.S. Federal Trade Commission, Washington D.C., July, 1992