Dichloromethane is a clear, colourless liquid with a penetrating ether-like odour and is slightly soluble in water. It is volatile and essentially non-flammable, however it can form an explosive mixture when mixed with oxygen.
Dichloromethane is used principally as a processing solvent in pharmaceutical industry in the manufacture of steroids, antibiotics, vitamins, and tablet coatings, as well as in paint removers, adhesives and as a flame retardant in conjunction with flammable alkane propellants in aerosols. It is also used as an extracting and degreasing agent, in electronics and manufacturing.
Most direct releases of dichloromethane are to the air from its use as a solvent in industry and in certain aerosol sprays and paint strippers. Oceans might also be a natural source of dichloromethane.
Impacts on human health and environment
Excessive exposure to dichloromethane may cause health effects on the blood, brain, digestive system, eye, heart, kidney, liver and skin, and may cause cancer.
Dichloromethane released to air will slowly degrade, though it may have some impacts on local wildlife if released in very large quantities. Releases to surface water, especially large accidental spills, may harm wildlife, but the effects will be reduced by the rapid evaporation of dichloromethane into the air. As a Volatile Organic Compound (VOC) it has been determined to have negligible photochemical reactivity and is unlikely to contribute significantly to the formation of harmful ground-level ozone or photochemical smog.
As dichloromethane is only slowly degraded in air, it may travel over significant distances, although potential impacts are unknown. Reactions in the lower atmosphere tend to eliminate dichloromethane before it reaches the upper atmosphere. Therefore, although it is a potential ozone depleter in the stratosphere, these impacts are not thought to be significant.
Dichloromethane is listed as priority substance in the Water Framework Directive.
Emission to air reporting threshold: 1000 kg/year
Emission to water reporting threshold: 10 kg/year
Data source: European Pollutant Emission Register