This Biopek MXP sample was tested using ASTM D5511 and demonstrated enhanced biodegradation of 15% after 120 days as compared to 0.3% biodegradation of a standard EPS sample.*

Tests of other formulations have shown greater degradation over longer periods of time.  Biodegradation tests on this formulation of Biopek MXP are continuing and will be updated periodically.

*Biodegradation rates of Biopek MXP are measured using the ASTM D5511 test method, which is intended to replicate conditions in biologically active landfills. Tests are generally conducted using samples of limited size that may not reflect the configuration of actual products.  Tests are also generally conducted in media that may not be reflective of local landfill conditions and using 20% to 45% solids content, which are not typical for most landfills; solids content in naturally wetter landfills range from 55% to 65%, while the driest landfills may reach 93%.  Biodegradation rates are lower where solid content is higher.  Actual biodegradation rates will vary in biologically active landfills according to the Biopek MXP formulation used [if applicable], the end-use product configuration, and the solid content, temperature, and moisture levels of the landfill.  Find biologically active landfill locations at


Important Notice: [Disclaimer]

Laws in California, Maryland, and Washington prohibit the sale of plastic packaging and plastic products that are labeled with the terms ‘biodegradable,’ ‘degradable,’ or ‘decomposable,’ or any form of those terms, or that imply in any way that the item will break down, biodegrade, or decompose in a landfill or other environment. These restrictions apply to all sales in or into these states, including such sales over the Internet.


As you are no doubt aware, federal, and state advertising laws impose an independent obligation on companies making environmental claims to ensure that all reasonable interpretations of the claims they make are “truthful, not misleading, and supported by a reasonable basis.”   Companies may be held liable for making representations about products they did not evaluate independently.  Although Styropek’s Biopek MXP has been tested using ASTM D5511 and demonstrated enhanced biodegradation of 15% after 120 days, these tests are limited to the material itself and do not apply to any customer end use products.  [Please refer to comments above regarding this reference to biodegradation results.]


Accordingly, we encourage our customers to independently evaluate the environmental claims they make for their products made with Biopek MXP and to ensure that adequate substantiation is on file to support such claims.  In this case, a particular use pattern, configuration, or the introduction of additives to the material, among other factors, may impact the manner in which an end-use product made with Biopek MXP degrades.  As such, it is imperative that each customer independently tests and understands the parameters of their product’s degradability before making such claims.  Any limitations on the product’s ability to degrade, including the availability of appropriate facilities, must be disclosed to avoid misleading customers or consumers.