Biodiesel and Ethanol Definitions and Retail Requirements
Commercial biodiesel stock used for biodiesel blends must be at least 99% biodiesel (no more than 1% diesel fuel) and meet ASTM specification D6751. Biodiesel blends must meet ASTM specification D975. Biodiesel blends made available for public use at retail locations may not exceed 20% biodiesel (B20), and biodiesel blends containing more than 5% biodiesel (B5) must be labeled as a biodiesel blend at the pump.
Ethanol is defined as nominally anhydrous ethyl alcohol that meets ASTM specification D4806. Ethanol blends made available for public use at a retail location must be labeled accordingly (e.g., E85).
(Reference Rules of the Tennessee Department of Agriculture 0080-05-12-.01 to 0080-05-12-.03)