Q. If I have some used oil and mix it with hazardous waste, can I still manage it as used oil? Or is the whole mixture now a hazardous waste?
A. The answer is, it depends. Some mixtures of hazardous waste and used oil must be managed as hazardous waste, but other mixtures can be managed under the alternative, less restrictive rules for used oil.
Used oil, including crankcase oil, transmission fluid, hydraulic fluid, machining oil, and lubricating oils, can be managed under the Used Oil regulations codified at 40 CFR Part 279, even if that oil has a hazardous waste characteristic.
Used Oil Mixed With “Listed” Wastes
A mixture of used oil and a hazardous waste that is listed in 40 CFR Part 261, Subpart D, a waste with an F-, K-, P-, or U-code, must be managed as a listed hazardous waste. Remember that a mixture of a hazardous waste and ANY solid waste is a listed waste. [40 CFR 261.3(a)(2)(ii)]
Used Oil Mixed With “Characteristic” Waste
When you mix used oil with a characteristically hazardous waste, a waste with a D-code or one listed only due to ignitability, corrosivity, reactivity, or toxicity, then the resulting mixture may or may not be a hazardous waste.
- If you have a mixture of used oil and a characteristically hazardous waste and the mixture has a characteristic, then you must manage it as hazardous waste.
- If you have a mixture of used oil and a characteristically hazardous waste and the mixture does not have any characteristics, then you may manage it as used oil.
- If you have a mixture of used oil and an ignitable hazardous waste (a waste that is hazardous solely because it exhibits the ignitibility characteristic) and the resulting mixture is NOT ignitable, then you may manage it as used oil whether or not other characteristics are present in the final mixture.
One more thing to note is that if your used oil contains more than 1,000 ppm total halogens, the EPA presumes that all those halogens got there because you mixed in some hazardous waste. This means that the EPA doesn’t have to prove you did indeed mix used oil and hazardous waste. Instead, you have to prove to them that you didn’t.