EPA Schedules Peer Review to Evaluate Risks of Some Trichloroethylene Uses

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By Pat Rizzuto

The Environmental Protection Agency will peer review its draft risk assessment of trichloroethylene that determined car mechanics, other small-business workers, and hobbyists inhaling the solvent could be harmed by it, according to a notice published June 7 (78 Fed. Reg. 34,377).

The peer review will be held in three meetings through the telephone and Internet on July 9, July 17, and Aug. 7.

Parties interested in addressing the peer review panel must contact EPA by July 6.

EPA's notice names 13 provisionally selected peer review panel members and the panel's chairwoman, Penny Fenner-Crisp, a private consultant who formerly worked at EPA, including serving as senior science adviser to the director of EPA's Office of Pesticide Programs.

Individuals who think any of the experts provisionally selected to serve on the TCE peer review panel have conflicts of interest must advise EPA of their concerns by June 28.

Trichloroethylene (TCE; CAS No. 79-01-6) is one of the first batch of five chemicals EPA's Office of Pollution Prevention and Toxics evaluated in its first public risk assessment initiative. OPPT released the five draft risk assessments in January (37 CRR 5, 1/7/13).

Narrow Scope of Uses Evaluated

TCE is produced in or imported into the United States in volumes of more than 250 million pounds or more annually, EPA's draft risk assessment said.

EPA's risk assessment focused on a small portion of the total volume because the majority of TCE, about 84 percent, is used in closed systems--thus limiting potential exposures--and transformed into other chemicals.

“Much of the remaining roughly 15 percent is used as a solvent for metals degreasing, leaving a relatively small percentage to account for all other uses, including its use in consumer products,” EPA's draft assessment said.

The assessment focused on TCE's use as a degreaser in small businesses, such as car repair shops, and consumer uses in clear protective coating sprays for arts and crafts hobbyists.

EPA's assessment included a scenario in which some people might be exposed to TCE because their work or lifestyle brought them near the small-business employee or a hobbyist using the degreaser or spray rather than because they used it.

Health Hazards

High concentrations of inhaled TCE--300 parts per million in air and higher--have depressed people's central nervous system and caused dizziness, lethargy, and other problems, even when the exposures were relatively short, meaning around two hours, EPA's draft assessment said.

Based on animal as well as human studies, chronic exposures to TCE can harm the liver, kidneys, the immune system, and the male reproductive system. Chronic TCE exposures also can cause certain cancers, “primarily kidney and liver, but also non-Hodgkin's lymphoma,” the draft assessment said.

Based on the hazards and known or estimated exposure information, the draft assessment concluded EPA has potential concerns:

• for commercial degreasers and nearby individuals who inhale high concentrations of TCE for a short duration due to possible developmental toxicity and neurotoxicity effects;

• for commercial degreasers and nearby individuals inhaling TCE chronically who might experience harmful liver, kidney, and immune system effects or develop tumors;

• for hobbyists using TCE as a degreaser and nearby bystanders inhaling it who could experience developmental toxicity from short-term, high-concentration exposures; and

• for hobbyists inhaling TCE when using it in clear protective sprays who also might experience developmental harm from short-term, high-concentration exposures.


EPA did not have concerns about bystanders who might inhale TCE sprayed by hobbyists working on an art or a craft project.

Broader Initiative

EPA's risk assessment of trichloroethylene is part of an initiative OPPT announced March 1, 2012, when it identified an initial group of seven chemicals it would begin to assess in 2012 as part of a broader effort to examine risks posed by 83 “Work Plan Chemicals” (36 CRR 269, 3/5/12; 36 CRR 388, 4/2/12).

Individuals wishing to voice conflict-of-interest concerns about any of the provisional peer reviewers should contact EPA by June 28 by submitting their views and information to http://www.regulations.gov marked Docket ID No. EPA-HQ-OPPT-2012-0723.

Individuals wishing to address the peer review panel or listen to its meetings must contact EPA contractor Susie Warner by July 6 at (301) 670-4990 or SWARNER@scgcorp.com.


EPA's draft risk assessment of TCE is available at http://www.epa.gov/oppt/existingchemicals/pubs/TSCA_Workplan_Chemical_Risk_Assessment_of_TCE.pdf.

An advance copy of EPA's notice is available at https://s3.amazonaws.com/public-inspection.federalregister.gov/2013-13576.pdf.

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