Under What Conditions Is Trichloroethylene Likely To Be a Carcinogen in Humans

This manuscript has been reviewed in accordance with the policy of the National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the Agency, nor does mention of trade names or commercial products constitute endorsement or use recommendation. Exposures to trichloroethylene (TCE) induce several types of cancer in experimental animals. TCE is metabolized in the body to multiple compounds, several of which are carcinogenic at relatively high doses in rodents. Risk assessments can be pursued with any one of the animal cancer endpoints after consideration of their relevance for humans exposed at low environmental concentrations. Among the TCE metabolites, dichloroacetic acid (DCA), trichloroacetic acid (TCA), chloral hydrate (CHL), and 1,2-dichlorovinylcysteine (DCVC) are each considered carcinogenic in rodents. Two of these, DCA and CHL, are used the...