Many people use the terms “waste oil” and “used oil” interchangeably. While both labels may identify the same fluid, from a regulatory standpoint there is a significant difference. Used oil is defined by the U.S. Environmental Protection Agency (EPA) as follows:

“Used oil is 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.”

This does not include vegetable or animal-based oils, but any petroleum or synthetic-based oil that has been used previously. In contrast, waste oil has been contaminated and is deemed not usable. For example, if the cap on a new oil drum had been leaking and water had gotten into the drum, this product would be deemed to be unusable and as such would be waste oil.

Due to some of the additive chemistries, it is entirely possible that this mixture of finished lubricant and water would exceed the chemical limits and need to be classified as waste oil.

Oils that are off-specification typically contain arsenic (5 ppm), cadmium (2 ppm), chromium (10 ppm) and lead (100 ppm), as well as have a minimum flash point of 100 degrees F and total halogens of more than 4,000 ppm. This would qualify the mixture as hazardous waste.

Hazardous materials are defined in various ways under a number of regulatory programs, including the Occupational Safety and Health Administration (OSHA), U.S. Department of Transportation (USDOT), etc.

Going back to the oil drum example, imagine if the seal on that drum had held and no water was allowed to enter. The lubricant was then put into service, and the seals leaked on the pump in which the lubricant was placed. Due to the leaking seals, water was allowed to enter the lubricant sump and mix with the oil.

Once this mixture was drained and placed into a container, it would be classified as “used oil.” While the end result of both of these processes was a mixture of oil and water, there is a significant difference in the requirements for each. Several plants have “used oil” being stored in drums, tanks and totes marked as “waste oil.”

In addition to the EPA’s used oil management standards, your business may be required to comply with federal and state hazardous waste regulations if your used oil becomes contaminated by mixing it with hazardous waste or waste oil. Hazardous waste disposal is a lengthy, costly and strict regulatory process. The only way to be sure your used oil does not become contaminated with hazardous waste is to store it separately from all solvents and chemicals and not to mix it with anything.

State and local regulations are often even more stringent than the EPA guidelines. For this reason, it is important to be familiar with your local laws and regulations regarding waste and used oil. There have been occurrences in which an inspector walked through a plant and assessed severe penalties and fines due to the mislabeling of used oil containers.

The easiest way to ensure that you are in compliance and can avoid these fees and headaches is to label containers correctly. Unless it is truly waste oil, it should be labeled as “used oil.”

Also, be sure to keep proper records. The EPA uses 12-digit identification (ID) numbers to track used oil. Transporters hauling used oil must have a valid EPA ID number, and generators, collection centers and aggregation points must use transporters with EPA ID numbers for shipping used oil offsite. Used oil transporters, processors, marketers and burners are required to keep records of each used oil shipment accepted for transport. These records for shipment must include:

  • the name and address of the generator, transporter or processor/re-refiner that provided the used oil for transport;
  • the EPA identification number (if applicable) of the generator, transporter or processor/re-refiner who provided the used oil for transport;
  • the quantity of used oil accepted; and
  • the date of acceptance.

These records are required to be kept for at least three years. It is recommended that you maintain these same records for the same period. As the ISO 55001 certification becomes more prevalent, this recordkeeping will be a positive step toward certification. It should be noted that any used oil shipments less than 55 gallons do not need an EPA tracking number. However, special permitting may be required by state and local governments.

While re-refiners, processors, transfer facilities and burners must have secondary containment systems (e.g., oil-impervious dikes, berms, retaining walls, etc.) to mitigate oil escaping into the environment in the event of a leak or spill, the EPA encourages generators to use a secondary containment system to prevent used oil from contaminating the environment.

Used Oil and Filters

During a root cause analysis/failure investigation, a post-mortem oil sample can contain a vast amount of information that can be very helpful in establishing the cause of failure. Simply pouring the used oil into a container is essentially just throwing away this potentially useful information.

The same is true of the filter and the oil it contains. The filter has been called the “hard drive” of the lubricant system, storing all the information about the system’s contamination. Frequently, once the filter is changed, it is placed on top of a drum to drain the oil and then thrown into a waste container.

A better way is to use a filter cutter. Take some of the filter media, rinse it with kerosene or a very light clean oil and conduct a patch test. You likely will be shocked and amazed at what you see. Based on the particles you find, you can determine if wear is occurring, what specific part of the equipment is wearing, and the type of wear that is taking place.

You can use the same approach for the oil contained in the filter. Both of these are excellent sources of information that are often just thrown away. Collecting data from these sources will help round out your oil analysis program.

In conclusion, it is critical that used and waste oil be identified and handled correctly. This can help to avoid significant costs and fines. In most cases, the “waste oil” in a plant is in fact used oil and is not subject to the special handling that is required of true waste oil, which is considered to be a hazardous material.