Chloroform is a colorless liquid which evaporates very quickly but breakdowns slowly once in the air. It is one of the most common hazardous air pollutants, estimated by EPA's Cumulative Exposure Project, to be found in every New England county. Most chloroform in the United States is used in the production of other chemicals. In the past, chloroform was used as a solvent, an anesthetic, a spot remover, in fire extinguishers and as a fumigant. The chlorination of water also produces chloroform as a by-product.
Most people ingest chloroform in their water and inhale it as it evaporates from water uses.
Chloroform can enter the air from factories that use it in manufacturing processes, from the evaporation of drinking water and sewage treatment facilities as well as from pulp and paper manufacturing. Urban areas may tend to have higher chloroform levels due the greater number of water treatment facilities. This indoor level may be from the combination of incoming outdoor air containing chloroform and the evaporation of chloroform from all residential chlorinated water uses. Chloroform may cause health effects due to its toxicity from both short term or acute exposures, such as when it is spilled, and also long term or chronic exposure, such as repeated occupational exposures. The type and severity of health effects depends on several factors including the amount of chemical you are exposed to and the length of time you are exposed .