Waste oil
Waste oil is defined as any petroleum-based or synthetic oil that, through contamination, has become unsuitable for its original purpose due to the presence of impurities or loss of original properties. == Differentiating between "waste oil" and "used oil" == The U.S. EPA defines the term "used oil" as any petroleum or synthetic oil that has been used, and as a result of such use is contaminated by physical or chemical properties.