Chloromethane is a colorless gas used in manufacturing and as a refrigerant. It can enter water through industrial discharge and may affect the nervous system if inhaled.

Chloromethane, also known as methyl chloride, is primarily an industrial chemical. It enters water systems through industrial discharges and leaks. Historically used as a refrigerant, its use has declined due to environmental concerns. Water utilities typically measure chloromethane using gas chromatography. While primarily a concern when inhaled, long-term exposure through drinking water is not well-studied. Environmental agencies monitor chloromethane levels to ensure they remain below established safety thresholds.