of polymeric ingredients within 180 days, plant toxicity and heavy metals. The ASTM 6400 standard is the regulatory framework for the United States and has similar requirements. Many starch-based plastics, PLA-based plastics and certain aliphatic-aromatic co-polyester compounds, such as succinates and adipates, have obtained these certificates. Additive-based bioplastics sold as photodegradable or Oxo Biodegradable do not comply with these standards in their current form. Compostability – ASTM D6002 The ASTM D 6002 method for determining the compostability of a plastic defined the word compostable as follows: that which is capable of undergoing biological decomposition in a compost site such that the material is not visually distinguishable and breaks down into carbon dioxide, water, inorganic compounds and biomass at a rate consistent with known compostable materials. This definition drew much criticism because, contrary to the way the word is traditionally defined, it completely divorces the process of "composting" from the necessity of it leading to humus/compost as the end product. The only criterion this standard does describe is that a compostable plastic must look to be going away as fast as something else one has already established to be compostable under the traditional definition. Withdrawal of ASTM D 6002 In January 2011, the ASTM withdrew standard ASTM D 6002, which had provided plastic manufacturers with the legal credibility to label a plastic as compostable. Its description is as follows: This guide covered suggested criteria, procedures, and a general approach to establish the compostability of environmentally degradable plastics. The ASTM has yet to replace this standard. Biobased – ASTM D6866 The ASTM D6866 method has been developed to certify the biologically derived content of bioplastics. Cosmic rays colliding with the atmosphere mean that some of the carbon is the radioactive isotope carbon-14. CO2 from the atmosphere is used by plants in photosynthesis, so new plant material will contain both carbon-14 and carbon-12. Under the right conditions, and over geological timescales, the remains of living organisms can be transformed into fossil fuels. After ~100,000 years all the carbon-14 present in the original organic material will have undergone radioactive decay leaving only carbon-12. A product made from biomass will have a relatively high level of carbon-14, while a product made from petrochemicals will have no carbon-14. The percentage of renewable carbon in a material (solid or liquid) can be measured with an accelerator mass spectrometer. There is an important difference between biodegradability and biobased