What are Used Oil Mixing Requirements?

The Office of Compliance Fact Sheet Series

What is used oil?

"Used oil" is oil that is:

• Contaminated with physical or chemical impurities;
• Used as a lubricant, heat transfer fluid, and hydraulic fluid, or from similar use; or
• Refined from crude oil or any synthetic oil.

What are the requirements for used oil mixtures?

Mixing used oil with other materials is permitted as long as the purpose of mixing is not to reduce the management requirements of the used oil or the material being added. The following describes the types of mixing specifically addressed in the EPA regulations. If other mixtures are being considered, additional guidance can be obtained from the EPA website.

Mixtures with fuel (except diesel). Used oil mixed with a fuel other than diesel is considered used oil, regardless of whether the resulting mixture is to be used as a fuel or recycled.

Mixtures with diesel fuel. Used oil mixed with diesel fuel is not considered used oil if the resulting mixture is used as fuel in engines owned by the persons who generated the original used oil. If the mixture is used as fuel by someone other than the generator of the used oil, the mixture is considered used oil, and the persons producing the original used oil are considered "processors" and are subject to stricter storage and handling requirements.

Mixtures with absorbent materials. Wipes, rags, and other absorbent material containing used oil require handling as used oil until the oil is removed from the material. EPA considers used oil satisfactorily removed when no visible sign of free flowing oil remains in the absorbent material. However, the material is still considered a used oil if the drained material is going to be burned to produce energy. [Note: After used oil has been removed, the material may need to be handled as a hazardous waste if it contains a listed hazardous waste or exhibits any property of hazardous waste.]

Mixtures with contaminated soils. EPA considers soil that is contaminated with used oil as used oil until the oil is removed from the material and no visible free flowing oil remains. Even after the used oil has been removed, contaminated soil is still considered as used oil if it will be burned for energy. [Note: After used oil has been removed, contaminated soil may need to be handled as a hazardous waste if it exhibits any property of hazardous waste.]

Mixtures with hazardous waste. Used oil mixed with hazardous waste is managed according to the storage, treatment and disposal requirements for hazardous waste, if the resulting mixture has any properties of hazardous waste. If the mixture has no hazardous waste properties then it is managed as used oil.

Is mixing used oil and hazardous waste a form of hazardous waste treatment?
Yes. Mixing a hazardous waste with used oil to render the waste as nonhazardous is considered hazardous waste treatment if the purpose is to make the waste suitable for burning or less hazardous. EPA may or may not require a permit for this mixing. Contact your EPA Regional office or State point of contact for further guidance.

State Requirements

CAUTION! State requirements for mixing used oil, as well as other used oil requirements, may be more restrictive.

Most states have their own solid waste programs, including used oil management, which are authorized by EPA. In many cases, states adopt the requirements established by EPA. However, in a few cases, states have revised the used oil regulations to meet the needs of the state.

For example, some states have a stricter definition of used oil, others broaden the definition of what contaminants make used oil a hazardous waste, and others do not allow mixing of used oil with anything other than used oil. These are just a few of the differences. Your state's used oil requirements can be obtained by contacting your state's used oil point of contact or your EPA Regional Office.

Additional Information

Contact the RCRA Hotline at 1-800-424-9346 or review the following EPA publications:

• Managing Used Oil: Advice for Small Businesses, EPA530-F-96-004, November 1996.
• Environmental Regulations and Technology: Managing Used Motor Oil, EPA/625/R-94/010, December 1994