In a risk assessment, EPA’s Office of Pollution Prevention and Toxics (OPPT) estimates that 300,000 workers and occupational bystanders are exposed to carcinogenic emissions of trichloroethylene (TCE) at dry-cleaning operations.

About one-tenth that number are also inhaling TCE emissions at small commercial degreasing operations; however, the Agency states that the greater cancer risks are associated with degreasing operations.  Noncancer risks from TCE primarily take the form of fetal cardiac defects, states the OPPT.

TCE is a volatile organic compound widely used in industrial and commercial processes; it also has limited use in consumer products.  Its consumption in the United States is 255 million pounds per year, making it one of the most widely used chlorinated solvents.

The OPPT performed the risk assessment of TCE as part of its Existing Chemicals Management Program under the Toxic Substances Control Act (TSCA).  The assessment also looked at arts and crafts uses of TCE.

In summary, the risk assessment showed the following risk findings:

Cancer risks

• There are cancer risk concerns for users and bystanders occupationally exposed to TCE when using TCE-containing degreasers and spot cleaners in small commercial shops and dry-cleaning facilities, respectively.
• Many of the degreaser and spot cleaning exposure scenarios exceed the target cancer risks of 10-6, 10-5, and 10-4.
• Occupational exposures to commercial degreasers show the greatest cancer risk when compared to the spot cleaning exposure scenarios.

Acute noncancer risks

• There are acute noncancer risks for developmental effects (i.e., cardiac defects) for most occupational and residential exposure scenarios.
• The degreaser exposure scenarios show greater acute risks for developmental effects than those reported for the spot cleaning exposure scenarios.

Chronic noncancer risks

• There are chronic noncancer risks for a range of human health effects in both occupational degreaser and spot cleaning exposure scenarios.
• The greatest concern is for developmental effects (i.e., fetal cardiac defects), followed by kidney effects and then immunotoxicity, with an overall higher chronic risk for the degreaser exposure scenarios.  In general, this concern is regardless of the type of exposure (typical vs. worst case) and the availability of room ventilation.
• There are chronic risks for reproductive effects and neurotoxicity for degreaser worker exposure scenarios and most of the degreaser bystander exposure scenarios.  However, the risk concerns for these effects are reported for fewer spot cleaning worker/bystander scenarios and are generally attributed to exposure conditions without room ventilation.
• There are chronic risks for liver effects, although the risks are less prominent than those reported for other health effects domains. These risks are found only in the degreaser worker/bystander exposure worst-case scenarios and the spot cleaning worker/bystander worst-case scenarios with no ventilation.

Environmental effects

The assessment did not examine environmental effects of TCE.  The OPPT notes that TCE’s impact on the environment is judged to be low because of its moderate persistence, low bioaccumulation, and low hazard for aquatic toxicity.  That said, the OPPT notes that the Agency’s regional offices and Office of Solid Waste and Emergency Response are addressing TCE contamination in groundwater and contaminated soils at a large number of sites.

OPPT’s risk assessment of TCE