EPA requires that fuel marketed as highway diesel fuel contain no visible evidence of dye solvent red 164. There is no regulatory requirement that would preclude that use of palm oil-derived biodiesel as a highway diesel fuel blendstock.

EPA and other interested parties could use spectrographic analysis in the field to determine whether the source of a red tint to diesel fuel resulted from contamination with red dye 164 or from another source. Furthermore, we do not believe that this will be an issue, as biodiesel will not go through pipelines.

Question and Answer was originally posted at Questions and Answers on the Clean Diesel Fuel Rules (PDF)(135 pp, 888 K, EPA420-B-06-010, July 2006, About PDF)