I had thought most of us had a clear understanding of the difference between these two types of oil waste streams but during a recent ISO audit I encountered a site who labeled all of their used oil as “waste oil”. While these terms sound interchangeable there can be differences in how they are managed.
First off, whether used oil or waste oil, it’s regulated by the Federal USEPA and State governments under the Resource Conservation and Recovery Act.
Now here’s the difference.
Used oil is oil that has been used, and as a result of such use, is now contaminated by physical or chemical impurities. The classic example is used oil drained from the engine of a truck or vehicle, and then stored for reuse or recycling.
Waste oil is oil that has not been used, but is found to be unsuitable for its originally intended purpose. For example, suppose a 55-gallon drum of oil was opened only to find that the cap on the drum had leaked, and now the oil was mixed with water, rendering it unsuitable for it’s original purpose. A big difference between the two is that waste oil maybe a hazardous waste. Oils that are off-specification (“waste oil”) typically contain: Arsenic 5 ppm, Cadmium 2 ppm, Chromium 10 ppm, Lead 100 ppm, and Total Halogens >4,000 ppm and could be characterized as hazardous waste.
So there is a difference in used oil vs waste oil. And, there is a difference in how they are regulated too. Used oil is considered a regulated waste, while waste oil maybe a hazardous waste. Nearly all plants have used oil, while very few ever have waste oil. There are additional regulations, such as the level of contamination of the used oil, regards to its eventual reuse, recycling, or disposal. It’s much better to have used oil vs waste oil.
Used oil tanks or containers (drums, totes, etc.) must, by regulation, be labelled as Used Oil – not unmarked, unlabelled, or as waste oil. Used Oil – that’s it.