Methylene chloride, known also as methylene dichloride and dichloromethane, is a colorless, volatile liquid with an ether-like odor. It is commonly found in septic tank cleaners, paint and varnish removers, degreasers, pesticides, aerosols, and Christmas bubble lights.

Methylene chloride irritates skin that comes in contact. When inhaled, it mimics carbon monoxide toxicity. Memory loss and liver and kidney damage are reported with chronic exposure. Methylene chloride is a known animal carcinogen and a suspected human carcinogen. When heated, methylene chloride emits a highly toxic phosgene gas (nerve gas). The use of products containing methylene chloride by people with heart conditions has resulted in fatal heart attacks.