If the EPA tightens up its perchloroethylene (“perc”) risk assessment, all entities emitting, discharging or remediating perchloroethylene may need to increase controls or delineate and remediate a little longer.

The EPA has proposed to lower the reference dose (RfD) from the 1988 level of 0.01 milligrams per kilograms per day (mg/kg/day) to 0.004 mg/kg/day, and set a first-ever inhalation exposure standard (reference concentration or RfC) of 0.016 milligrams per cubic meter (mg/m3). The EPA’s process is being challenged by the Department of Defense, which has stated that “DoD is very concerned about the apparent lack of consistency in the evaluation of TCE and PCE, the latter also under interagency review. As the PCE document states, ‘Tetracholoroethylene is closely related structurally to trichloroethylene, and the two chemicals cause similar toxic effects, many of which are attributed to metabolic activation of the parent compounds.’ Given the EPA’s stated objective of considering toxicities of closely related chemicals together, DoD finds the lack of consistency troubling.”

Article Authored by McAfee & Taft Attorney: Mary Ellen Ternes.

and links.