DICHLOROMETHANE FACT SHEET
MCL: 5 PPB
Source: Paint remover, extraction, cleaning solvent
Effect: Nervous system, liver, blood damage; Cancer
Followup: Treat and retest quarterly
Treatment: Granular activated charcoal
Dichloromethane (DCM) is a colorless organic liquid with a sweet, chloroform-like odor. The greatest use of DCM is as a paint remover. Other uses include: solvent and cleaning agent in a variety of industries, a fumigant for strawberries and grains; and to extract substances from foodstuffs.
Production of DCM has been decreasing: from a high of 561 million lbs. in 1986, to roughly 410 million lbs. in 1993. It is released in wastewater primarily from the following industries: Paint and ink, aluminum forming, coal mining, photographic equipment and supplies, pharmaceutical, organic chemical/plastics, metal foundries and laundries. DCM is also formed during the chlorination of water.
From 1987 to 1993, according to EPA’s Toxic Chemical Release Inventory, DCM releases to land and water totalled over 2.1 million lbs. These releases were primarily from medicinals and botanicals industries. The largest releases occurred in Connecticut and New York.
What happens to DCM when it is released to the environment? Most DCM is released to air where it is degraded by sunlight within a few months. Releases to water evaporate very quickly. It will evaporate from soil but can also leach through soil to ground water. DCM is not likely to accumulate in aquatic life.
Short-term: EPA has found dichloromethane to potentially cause the following health effects when people are exposed to it at levels above the MCL for relatively short periods of time: Damage to the nervous system and to blood.
Long-term: Dichloromethane has the potential to cause the following effects from a lifetime exposure at levels above the MCL: liver damage; cancer.
Treat and retest quarterly.
Granular activated charcoal in combination with Packed Tower Aeration.