United States. Congress, Energy Independence and Security Act of 2007…
“ Unless the American Society for Testing and Materials has adopted a standard for diesel fuel containing 20 percent biodiesel (commonly known as 'B20') within 1 year after the date of enactment of this subsection, the Administrator shall initiate a rulemaking to establish a uniform per gallon fuel standard for such fuel and designate an identification number so that vehicle manufacturers are able to design engines to use fuel meeting such standard. ”
