In general, the EPA does not consider used oils to be hazardous waste. In establishing proper management standards for these wastes, the EPA presumed that recycling, from re-refining to burning as fuel, would occur. The used oil rules at 40 CFR 279 are less burdensome than the hazardous waste regulations (40 CFR 260-270). In some circumstances, the EPA even allows certain mixtures of used oil and hazardous waste to be managed under the less stringent used oil rules. Recycling used oil under Part 279 has great advantages and it is worth considering which used oil/hazardous waste mixtures can take advantage of these regulations.
What Is Used Oil
The U.S. EPA defines used oil as “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” [40 CFR 279.1]. Though not explicitly stated in this definition, the EPA’s used oil regulations apply to lubricating, hydraulic, cutting, cooling, and other similar oils—but not to fuel oils.
Types of Mixtures
Used oil and hazardous waste mixtures fall into two categories: used oils that are mixed with listed hazardous waste (i.e., wastes described at 40 CFR 261.31—261.33), or used oils mixed with characteristic-only hazardous wastes. The EPA prohibits the management of mixtures of used oil and listed waste from management under 40 CFR 279. These mixtures must be managed under the hazardous waste management requirements [40 CFR 279.10(b)(1)(i)]. So, it is mixtures of used oil and certain characteristic hazardous wastes that may take advantage of the used oil standards.
When Used Oil and Hazardous Waste Can Be Managed as Used Oil
The hazardous waste is ignitable-only (D001), but is not ignitable when mixed with used oil, even if the resulting mixture exhibits some other hazardous waste characteristic(s)
The hazardous waste was characteristic-only, and the mixture displays no characteristics.
Used Oil Mixed With Ignitable Hazardous Waste
An ignitable hazardous waste (D001) is a hazardous waste that exhibits no characteristics other than ignitibility, and/or is listed only for ignitibility.
A mixture of used oil and ignitable hazardous waste may be managed as used oil, as long as the mixture is not ignitable, even if the mixture exhibits other hazardous waste characteristic(s) (i.e., toxicity for heavy metals) [40 CFR 279.10(b)(2)(iii)].
Used Oil Mixed With “Characteristic” Hazardous Waste
A mixture of a characteristic hazardous waste and used oil can be managed as used oil as long as the mixture does not exhibit any characteristic [40 CFR 279.10(b)(2)(ii)].
Characteristic-only hazardous wastes include those wastes listed on the F-, K-, P-, or U-lists solely because they exhibit a hazardous characteristic (i.e. ignitibility (I), corrosivity (C), reactivity (R), or toxicity (E)).
There are approximately 30 listed wastes found in 40 CFR 261.31—261.33 that the EPA has listed solely on the basis of the waste exhibiting one or more of the characteristics at 40 CFR 261, Subpart C. In their descriptions at 40 CFR 261, Subpart D, these listed wastes are followed by one or more of the following hazard codes: I, C, R, or E.
Special Circumstances for Conditionally Exempt Small Quantity Generators
As established at 40 CFR 261.5, Conditionally Exempt Small Quantity Generators (CESQGs) are largely exempt from RCRA hazardous waste regulations. Any hazardous waste, including acutely hazardous, or toxic wastes generated by a CESQG may be mixed with and managed as used oil, even if the resulting mixture exhibits hazardous waste characteristics. [40 CFR 261.5(j)].
Check Your State Regulations
Used oil recycling is one area of waste management regulations where State laws, regulations, and policies can vary widely from Federal standards. Before mixing used oil and hazardous waste, check with your state’s EPA to make sure the Agency approves your procedures. States may prohibit one or more of these mixes or impose additional requirements for recycling any/all used oils.
Mixing hazardous waste and used oil has many advantages for generators. As long as the rules at 40 CFR Part 279 are followed, mixtures of certain types of hazardous waste and used oil are exempt from many of the most stringent RCRA regulations, saving generators time and money.