• Used oil must have been refined from crude oil or made from synthetic materials.
• Oils used as lubricants, hydraulic fluids, head transfer fluids, buoyants, and for other similar purposes are considered used oil.
• Used oil must be contaminated as a result of being used.

Used oil includes “any oil that has been refined from crude oil or any synthetic oil that has been used and, as a result of such use, is contaminated by physical or chemical impurities.” To meet the Environmental Protection Agency’s (EPA’s) definition of used oil, a substance must meet each of the following criteria:

1. Origin: Used oil must have been refined from crude oil or made from synthetic materials. Animal and vegetable oils are excluded from EPA’s definition of used oil under this regulation.
2. Use: Oils used as lubricants, hydraulic fluids, head transfer fluids, buoyants, and for other similar purposes are considered used oil. Unused oil such as bottom clean-out waste from virgin fuel oil storage tanks or virgin fuel oil recovered from a spill do not meet the definition of used oil. EPA’s definition also excludes products used as cleaning agents or solely for their solvent properties, as well as certain petroleum-derived products such as antifreeze and kerosene.
3. Contaminants: To meet EPA’s definition, used oil must be contaminated as a result of being used. This includes residues and contaminants generated from handling, storing, and processing used oil. Physical contaminants can include dirt, metal scrapings, or sawdust. Chemical contaminants could include solvents, halogens, or saltwater.

The used oil management standards at Part 279 apply differently depending upon how oil is handled.

Examples of used oils:

• Brake fluids
• Compressor oils
• Coolants
• Electrical insulating oil
• Emulsions
• Engine oil
• Fluids used in hydraulic equipment
• Greases
• Industrial hydraulic fluid/industrial process oils
• Laminating oils
• Lubricant sprayed onto gears
• Metal-working fluids and cutting oils
• Mineral oil
• Motor oil
• Oils used as buoyants
• Refrigeration oil
• Refrigeration coolant
• Synthetic oil
• Transmission fluid
• Used oil residues or sludges
• Wire drawing solutions

What does not qualify as a used oil?

• Animal and vegetable oil (even when used as a lubricant)
• Antifreeze
• Kerosene
• Oils used for their solvent
• Petroleum distillates used as solvents to solubize or mobilize and solvents manufactured from synthetic materials
• Used oil re-refining distillation bottoms that are used as feedback to manufacture asphalt products (exempt at 261.4(b)(14))
• Virgin oil (tank bottoms)
• Virgin oil spill clean-up materials
• Wash waters contaminated used oil
• Certain waste oils or oily wastes