Biodiesel Definition and Specification

Biodiesel is defined as a fuel that is comprised of mono-alkyl esters of long-chain fatty acids derived from vegetable oils or animal fats and that conforms to ASTM standard D6751. All fuel consisting of at least 99% biodiesel (B99) that is sold or offered for sale must conform to ASTM standard D6751.

(Reference 815 Illinois Compiled Statutes 370/4)