16 CFR § 311.1 - Definitions.
As used in this part:
(a) Manufacturer means any person who re-refines or otherwise processes used oil to remove physical or chemical impurities acquired through use or who blends such re-refined or otherwise processed used oil with new oil or additives.
(e) Used oil means any synthetic oil or oil that has been refined from crude oil, which has been used and, as a result of such use, has been contaminated by physical or chemical impurities.
(f) Re-refined oil means used oil from which physical and chemical contaminants acquired through use have been removed.