In a move with potentially far-reaching implications, on September 28, 2011, the U.S. Environmental Protection Agency (EPA) issued its long-awaited final health assessment for trichloroethylene (TCE). The Assessment follows two and a half decades of vigorous scientific and policy debate and sets forth conclusions suggesting that TCE is far more toxic and carcinogenic than was previously assumed. It portends a potential revisiting of TCE-related cleanup standards for soil, groundwater, and vapor intrusion at and adjacent to contaminated properties, including those previously granted regulatory closure, maximum contaminant levels for drinking water, and allowable levels of emissions from industrial facilities and from a variety of consumer products in which even small levels of TCE are typically used. It almost surely will become the subject of litigation on a variety of fronts and may well soon become a topic of legislation and rulemaking.

TCE has been produced commercially since the 1920s, and was widely used by manufacturing companies as a metal degreaser. In the 1930s, TCE was introduced for use in dry cleaning, but was replaced in the 1950s by another chlorinated solvent, perchloroethylene (PCE). TCE has also been an ingredient of a variety of products including adhesives, paint strippers, paints, lacquers and varnishes, spot removers and typewriter correction fluid.

Because of TCE’s widespread use before the advent of modern environmental regulations, it is one of the most common contaminants of concern at former manufacturing sites, military bases, and some dry cleaner locations. According to EPA, TCE is one of the most common chemicals found at its Superfund sites. As a dense, non-aqueous phase liquid, it is difficult and expensive to remediate in the soil and groundwater and, because it is volatile, it raises indoor air quality concerns in overlying buildings. Plaintiffs in toxic tort cases have also asserted, with varying degrees of success, that exposure to TCE is the cause of cancer and other personal injuries.