Several states have begun to implement U.S. EPA Region IX's proposed Interim Removal Action Level ("RAL") of 15 ug/m3 for trichloroethylene ("TCE") in indoor air. Notwithstanding that U.S. EPA headquarters is currently reviewing the science relied upon by Region IX in setting the RAL, California's Department of Toxic Substances Control has already begun to require mitigation in industrial and commercial buildings when that concentration is reached. Other U.S. EPA regions have also adopted Region IX's RAL. For example, Region III recently ordered the evacuation of a military installation in Virginia when the indoor air levels of TCE exceeded 27 ug/m3.
In addition to California, New Jersey has also indicated that it is considering adopting a similar acute exposure limit for TCE. We will continue to monitor U.S. EPA and state actions with respect to short-term TCE exposure limits.