Special Topics in Environmental Management

Recyclable Used Oil: Avoiding PCB Contamination

In a 2018 fact sheet, the EPA discussed the persistent problem of oil contaminated with polychlorinated biphenyls (PCBs) getting inadvertently mixed with recyclable used motor oil. Based on the Agency’s experience with mixing incidents, the fact sheet summarizes best management practices (BMPs) that both oil collection centers and recyclers can use to ensure that PCB-contaminated oil does not contaminate recyclable oil.

Motor Oil

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Dilution Prohibited

Mixing PCB-contaminated oil with used motor oil is particularly problematic if the PCB concentration equals or exceeds 50 parts per million (­> 50 ppm). While used motor oil can be recycled, introduction of any amount of oil contaminated with ­> 50 ppm PCBs means the entire volume must be disposed of in accordance with the PCB regulations. Moreover, all tanks, equipment, and vehicles must be decontaminated. While PCB-contaminated oil mixed with used oil becomes diluted, the Toxic Substances Control Act (TSCA) prohibits dilution of the PCB concentration for disposal purposes.

Cost of Contamination     

The consequences of improper mixing can be costly. The fact sheet describes an incident in which a recycling company delivered 600 gallons (gal) of oil to the municipal used oil collection center in Madison, Wisconsin. Neither the recycler nor the city knew that the oil was contaminated with ­> 50 ppm PCBs. The contaminated oil was mixed with non-PCB oil, resulting in 17,000 gal of PCB-contaminated oil. This meant, in part, that both the recycler and the city became subject to potential TSCA enforcement. It also resulted in cleanup and disposal costs totaling $206,000. Following the incident, the city instituted a “strict” sampling procedure for oil delivered to its collection center.

Following are key BMPs the EPA recommends for both municipal used oil collection centers and used oil recyclers.

Collection Centers

  • Obtain a sample—called the retain sample—of used oil from each batch received.
  • Sample the collection tank before shipping the used oil off-site. Lock and label used oil tanks immediately after sampling. If the space and funds are available, use dual-compartment tanks or dual tanks wherein one side or tank can be locked when full to await test results while the other side or tank remains open to collect used oil.
  • If the used oil in the tank contains quantifiable levels of PCBs but < 50 ppm PCBs, use the retain samples to determine whether the PCBs are from a source with a = 50-ppm concentration that has been diluted. If the used oil contains = 50 ppm PCBs or contains < 50 ppm PCBs as a result of dilution, label the tank or container and notify the state and regional PCB coordinators immediately.
  • Offer to submit test results to used oil recyclers before pickup. Testing for PCBs in oil can be done only by accredited laboratories to be defensible. Field test kits cannot reliably detect PCBs in used oil. As of 2017, analysis costs around $60 to $150 per sample, depending on the desired turnaround time.
  • Post signs at collection facilities providing notification that only used oil should be put in tanks.
  • Keep all used oil collection containers and tanks closed and secured in a fenced area or inside a building to prevent access when the collection center is closed.


  • Educate commercial and municipal collection centers and transporters on the importance of preventing the mixing of potentially PCB-contaminated oil with other used oils, such as used motor oils.
  • Obtain analytical results showing the PCB concentration from each collection tank at a commercial or municipal collection center before pickup. Do not rely on word of mouth or experience.
  • Offer to analyze samples from commercial and municipal collection centers before pickup if they decline to submit test results.
  • Take a retain sample from each incoming shipment of used oil. Off-load the used oil into a guard tank, which should remain locked while waiting for PCB test results. Guard tanks reduce cleanup costs if a used oil shipment is contaminated with PCBs.
  • If PCBs are detected in the used oil at the guard tank, analyze retain samples collected before pickup to find the likely source.
  • Maintain records that document the testing and analysis of used oil samples to determine the presence and concentration of PCBs before any processing or rerefining of the used oil.

40 Years After Ban, Diligence Still Needed

While most manufacturing and processing uses of PCBs were banned in 1979, along with commercial distribution, the substance stubbornly persists in used oil. Collection centers and recyclers should have firm procedures in place to ensure they do not face regulatory crises, such as the one that occurred in Madison.