ASTM Standards for Oxo-Biodegradable Plastics

EPI supports the development of international standards relating to the establishment of practical and measurable specifications and methods for the testing of degradable and biodegradable products. The American Society for Testing and Materials (ASTM) recognized oxo-biodegradation and ASTM D6954-04 is the standard guide developed for Exposing and Testing plastics that Degrade in the Environment by a Combination of Oxidation and Biodegradation.

Product testing in EPI’s laboratory is done using relevant ASTM test methods and are described in ASTM Standards & Methods Employed by EPI for Degradable Plastics.

Standards for Biodegradable Plastics

Degradation and biodegradation requirements of plastics vary considerably with intended use including disposal compartments and EPI is working with ASTM and European standards to evaluate oxo-biodegradable claims in various environments such as landfill, soil, litter, commercial and home composting.

Unfortunately, at the present time, there are no standards available for the performance of degradable and biodegradable plastics in other disposal environment other than composting.

Commonly quoted standards for compostable plastics are ASTM D6400-04 and EN 13432 and are related to the performance of plastics in a commercially managed compost environment and are not biodegradation standards. Both standards were developed for hydro-biodegradable polymers (eg. aliphatic polyesters plus modified starch) where the mechanism inducing biodegradation is based on reaction with water and state that in order for a product to be compostable, the following criteria need to be met:

  1. Disintegration, the ability to fragment into non-distinguishable pieces after screening and safely support bio-assimilation and microbial growth;
  2. Inherent Biodegradation, conversion of carbon to carbon dioxide to the level of 60% and 90% over a period of 180 days for ASTM D6400 and EN 13432 respectively
  3. Safety, that there is no evidence of any eco-toxicity in finished compost and soils can support plant growth; and
  4. Toxicity, that heavy metal concentrations are less than 50% regulated values in soil amendments.

EPI’s TDPA® additives meet the requirements of compostability outlined in these standards, except for the rapid carbon to carbon dioxide conversion rate. Plastics made with TDPA® additives degrade and ultimately biodegrade slower than the rate specified in these standards. This does not mean that they will not biodegrade; they just convert the carbon to carbon dioxide in a slightly longer time frame. Many naturally occurring materials, all biodegradable, do not convert in the time frames established by ASTM D 6400-04 and EN 13432, which are explained in the Position Statement. To date, our scientists have been unsuccessful in making the point at these standards organizations that the metrics of these standards are inconsistent with the stated objective – to ensure that plastics entering managed compost facilities biodegrade “at a rate comparable to known compostable materials.”

At present, although EPI’s specially designed TDPA® modified plastic bags are used successfully in some managed industrial composting operations, they do not meet the requirement of the compostable plastics standards relating to the rate of biodegradation in a compost environment and as such, EPI does not claim compostability for its products

Other Applicable Standards & Regulations

ISO14021 is an international standard that specifies the need for proof of performance in labeling and packaging of products claiming to provide an environmental benefit. EPI follows this standard and requires its licensees to do so as well.

EPI also follows the guidelines set by the United States Federal Trade Commission (FTC) for requirements relating to environmental claims benefits stated in section 5 of the FTC Act, 15 U.S.C. & 45, which prohibits “unfair and deceptive acts or practices in or affecting interstate commerce.” EPI values the promotion of corporate branding and is sensitive to the dangers that misleading advertising can have on the public perception of major corporate brands.