Stricter environmental regulation of used oils and fluids requires that extensive testing be done before recycling or disposal. Heavy metals, chlorinated solvents and PCBs are the primary analytes of concern. A variety of analytical methods exist, ranging from complicated laboratory analyses such as gas chromatography/mass spectroscopy to simpler field methods that provide fast, qualitative results. Depending on the type of fluid being tested and the method of disposal or recycling for the fluid in question, the cost of testing can run from five dollars per sample to several thousand dollars per sample. Knowledge of available testing techniques can significantly lower the cost of complying with these complicated regulations.Waste lubricating oil is a valuable resource that can return much of its value when re-refined for reuse or when burned for energy recovery. Unfortunately, used oil can also be a source of hazardous materials which enter the oil either during normal engine use or are added in an effort to hide or dispose of hazardous chemicals at low cost. While the EPA has decided not to list used oil itself as a hazardous waste (for the time being) it still must be tested to ensure that it has not been mixed with a hazardous waste. Any oil that has been mixed with a hazardous waste is automatically also classified as a hazardous waste. When this occurs, an asset becomes a liability and instead of selling the used oil for profit, the owner must pay to have the hazardous waste properly disposed of.Used oils must be tested for different parameters depending on the type of oil and the end use. Oils that are to be burned as on-spec fuel are subject to tighter regulations than are oils that are to be re-refined. Used oils that are to be burned for energy recovery are subject to the following maximum levels as outlined in 40 CFR 279.11. Used oils that are to be recycled in other ways such as re-refining must meet the total halogen and PCB regulations. Except for certain metalworking and compressor fluids which contain chlorinated paraffins, all used oils fall under the “rebuttable presumption” rule for total halogens and must be tested. This means that any oil that tests at greater than 1000 ppm total halogens is assumed to have been mixed with a hazardous waste unless it can be shown that the oil contains less than 4,000 ppm total halogens and that the oil contains less than “significant” quantities of hazardous halogenated organic compounds. Although it is not clear, it is generally agreed that significant quantities means 100 ppm. Oils also must not contain detectable levels of PCB, which usually works out to be 2 ppm although this is decided on a case by case basis.