During use, antifreeze is circulated throughout the engine coolant system and comes into contact with various metal parts. Recent studies conducted by the American Society for Testing and Materials determined roughly 40 percent of waste antifreeze samples were hazardous waste due to elevated levels of lead.
Evidence suggests that lead contamination is from contact with the soldering seals of the radiator.
If used antifreeze is mixed with other wastes such as used oil, the entire mixture may need to be disposed of as hazardous waste. Keeping your wastes segregated will increase your disposal options and reduce your disposal costs. Before you can properly store or dispose of waste antifreeze, you must determine whether it is a hazardous or non-hazardous waste. You can either assume that it is a hazardous waste and dispose of it as such, or you can submit a sample for laboratory analysis. We encourage you to shop around when selecting a laboratory.