By Bret A. Stone
Trichloroethylene (“TCE”), a chlorinated solvent used as a degreaser, just moved up the cancer-causing ladder from “probable” carcinogen to a human carcinogen regardless of the route of exposure. The last EPA assessment of TCE was in 1987.
According to the EPA, the purpose of the Toxicological Review is to provide scientific support and rationale for the hazard and dose-response assessments given in its Integrated Risk Information System (IRIS) pertaining to chronic exposure to TCE. TCE is a volatile chemical widely used by industry as a chlorinated solvent; and unfortunately, it is also widely found at contaminated sites, including hundreds of Superfund facilities across the country. TCE is a breakdown product (aka, daughter product) of tetrachloroethylene (“PCE”), another chlorinated solvent commonly used in the dry cleaning industry. Therefore, TCE can be found in areas where TCE itself was never used.
The Toxicological Review concludes that based on the available human epidemiologic data and experimental and mechanistic studies, “TCE poses a potential human health hazard for noncancer toxicity to the central nervous system, kidney, liver, immune system, male reproductive system, and the developing fetus. The evidence is more limited for TCE toxicity to the respiratory tract and female reproductive system.”
The chief impact of this new hazard classification will likely be on the developing vapor intrusion standards and on groundwater remediation projects.