Trichloromethane is a clear, colourless, volatile, non-flammable liquid with a characteristic odour. It evaporates very quickly and has limited solubility in water, but is miscible with most organic solvents.
Trichloromethane is primarily used as a solvent, as a chemical intermediate (production of hydrochlorofluorocarbon-22 (HCFC 22)), and in pesticide formulations. It was formerly used widely as an anaesthetic, but this use has been abandoned due to its toxic effects.
Trichloromethane may enter the environment as a result of its use as an industrial solvent, extractant and chemical intermediate. Indirect production as a result of the chlorination of drinking water, sewage and cooling water are other sources. The majority of releases will be to the atmosphere and releases to land and water will mostly evaporate into the air. Trichloromethane occurs also in the environment from natural origin.
Impacts on human health and environment
Excessive exposure to trichloromethane may affect the brain, digestive system, eye, kidney, liver and skin, and may cause cancer.
As an atmospheric pollutant trichloromethane is not likely to cause significant local impacts. Hazard to water dwelling organisms may be significant for major accidental spills. The majority of releases to land and water will be lost by evaporation and partition into the atmosphere. However, spills to land may result in leaching to groundwater where it may reside for longer periods of time. It is not known to bioconcentrate in the food chain and little trichloromethane will be adsorbed to soil or sediment. As a VOC it has a low tropospheric ozone creation potential and a negligible photochemical reactivity. It is thus unlikely to contribute significantly to ground-level ozone or photochemical smog.
Trichloromethane has a long lifetime in the atmosphere (months) and may be transported over long distances through air.
Trichloromethane is listed as a priority substance in the Water Framework Directive.
Chloroform is a priority substance under Regulation 793/93. The risk assessment report is currently under discussion by the Committee of Technical Experts representing Member States, Industry and NGOs.
Emission to air reporting threshold: 500 kg/year
Data source: European Pollutant Emission Register