Information presented in this publication is intended to provide a general understanding of the statutory and regulatory requirements governing parts washing. This information is not intended to replace, limit or expand upon the complete statutory and regulatory requirements found in the Illinois Environmental Protection Act and Title 35 of the Illinois Administrative Code.

Parts washers (e.g., degreasers) are commonly used in manufacturing or maintenance operations to clean parts or components. Parts washers use cleaning solutions that eventually become spent and must be disposed of properly. Spent parts washer cleaning solutions are considered a special waste in Illinois because they may be a hazardous waste and are an industrial process waste. Spent solvents are almost always a hazardous waste. Both solvent and aqueous parts washers generate sludge, which is usually hazardous because it contains toxic metals and solvents from the parts cleaned. Absorbents used to wipe parts off after being washed are also hazardous if they contain toxic metals at concentrations exceeding regulatory limits or listed hazardous solvents, and used oil may also contain hazardous waste.