ASTM International's Committee on Plastics recently approved revisions to standard D6866, Test Methods for Determining the Biobased Content of Solid, Liquid, and Gaseous Samples Using Radiocarbon Analysis. This standard was originally approved in 2004, and is used by the U.S. Department of Agriculture's (USDA) BioPreferred^® Program, by EPA when it is determining the sustainability of plastics, and by other corporations using biobased plastics. D6866 is used to determine the percent of carbons present in the final product that come from plant-biomass carbon feedstock versus petroleum-based carbon feedstocks.