Bioplastics share many of the valuable functional characteristics of conventional plastics such as processability, durability, and recycling. Compostability however, is a functional characteristic that is unique to some types of bioplastics.
Composting, like recycling, is an attractive means of avoiding landfill disposal, and there has been an increased consumer demand in biodegradable/compostable plastics.
Industrial composting differs from home composting in that the process is much more closely managed and monitored to ensure high temperature conditions.
This document addresses claims made relative to industrial composting only. It is important that composting claims for consumer products be made carefully, with consideration of appropriate scientific standards, state and federal regulations, and local infrastructure.
A marketing claim around any form of biodegradability must be based on the specific product for which the claim is being made.
Such claims cannot be made based solely on the compostability attribute of the upstream resin. While a consumer product clearly cannot be compostable unless the underlying materials from which it is made are compostable, it is not a sufficient condition that the underlying materials be compostable.
According to the FTC Green Guides, compostability claims should be qualified with supporting evidence that the “entire product or package will completely break down and return to nature, within a reasonably short period of time after customary disposal.”
Compostability rate is thickness dependent.
ASTM has developed standard specifi cations, ASTM D6400 and ASTM D6868, for specifying industrial compostability as follows:
- “Completely break down”: Greater than 90 percent of the article must not remain.
- “Return to Nature”: Since the products of composting including bioplastic articles will be incorporated into the soil, the D6400 specification goes further to define constraints on ecotoxicity and regulated metals of the composted product to prevent bioaccumulation of materials in the soil.
- A “reasonably short period of time”: The D6400 specification for industrial composting defines 84 days as reasonable for fragmentation of the product, and 180 days for complete mineralization in a properly managed composting facility.
- “Customary disposal”: Industrial composting should already be a customary form of disposal in the community where this product will be used and treated.
- “Thickness Dependent”: The ability for a material or product to compost within the time frame of the specifi cation is dependent upon its thickness. Thus, a material must also state the maximum thickness at which the compostability requirements are passed.6 ASTM D6868 is a similar specification for multilayer materials. This specifi cation requires that every layer also pass the biodegradation requirements of ASTM D6400 independently
- Will the average consumer likely understand the claim?
- What is the test method and qualifying specification for the claim?
- Do the tests accurately reflect how the advertised product or package will perform in a typical industrial composting facility?
- Has independent testing and certification (e.g., ASTM D6400, D6868) by an approved laboratory been completed to confirm compostability? (A qualified claim implies that product/packaging is tested and specified according to standards by ‘voluntary consensus standard body’ and certified by independent party)
- Does the claim clearly refer to product, packaging or both?
- Are there recycling signs or other symbols or images on the packaging or marketing materials that may confuse consumers?
- How long does it take to achieve complete composting of the product or packaging and is this acceptable for the current program?
- What is the availability of an industrial composting facility and collection program in the location where the product or packaging is available, and will they accept the product or packaging?
- Are clear and conspicuous disclaimers included to account for limited facility availability, variances from the certification conditions, improper collection/disposal/recycling or other factors potentially important to purchasers?
- Have you complied with any local, regional or state labeling requirements (e.g. under California law PRC 42357, no “biodegradable” claims are allowed on any plastic product, and compostable labels are allowed only if they meet ASTM D6400/D6868)?
- Does the claim indicate an affiliation with any testing and/or certifying agency?
- Are claims/disclaimers on websites and other marketing materials accurate and consistent with the actual claims on product or packaging?
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