January 19, 2023

Revised Risk Determination for the Solvent TCE Finalized by EPA

The solvent trichloroethylene (TCE) “presents an unreasonable risk of injury to human health,” according to a revised risk determination finalized last week by EPA. The agency describes TCE as a volatile organic compound used mainly in industrial and commercial processes. One major use of TCE is as a solvent to remove grease from metal parts and another is in the making of other chemicals such as HFC-134a, a refrigerant. TCE is also found in some consumer products used for cleaning and furniture care, arts and crafts, and spray coatings.

Adverse health effects associated with exposure to TCE include developmental toxicity, reproductive toxicity, liver toxicity, kidney toxicity, immunotoxicity, neurotoxicity, and cancer, EPA says. The severity and potential irreversibility of the health effects associated with TCE exposures prompted EPA to use its “whole chemical risk determination approach” for the chemical rather than making separate risk determinations for individual conditions of use. The agency determined that only two of the 54 conditions of use it evaluated—distribution in commerce and consumer use of TCE in pepper spray—did not drive its determination regarding unreasonable risk.

The revised risk determination for TCE does not assume that all workers exposed to the chemical always or properly wear personal protective equipment. This “reflects EPA’s recognition that certain subpopulations of workers exist that may be highly exposed” for a number of potential reasons, the agency explains in a press release. For example, some workers could have increased exposure if they are not covered by OSHA standards or if the OSHA permissible exposure limit alone may be inadequate for ensuring that workers’ health is protected, which EPA states “is the case for TCE.”

OSHA’s PEL for TCE is 100 ppm as an 8-hour time-weighted average, its acceptable ceiling concentration is 200 ppm, and its acceptable maximum peak above the acceptable ceiling concentration for an eight-hour shift is 300 ppm for a maximum duration of five minutes in any two hours.

EPA intends to begin a risk management rulemaking for TCE.

“EPA has received public comments from industry respondents about occupational safety practices currently in use at their facilities and will consider these comments, as well as other information on use of PPE, engineering controls and other ways industry protects its workers as potential ways to address unreasonable risk during the risk management process,” the agency says.

For more information, see EPA’s press release and its risk evaluation webpage for TCE.

Related: A final toxicological profile published in 2019 by the Agency for Toxic Substances and Disease Registry states that workers at facilities that use TCE for metal degreasing may be exposed to elevated levels of the substance. ATSDR’s toxicological profile further characterizes the toxicologic and adverse health effects information for TCE.