July 3, 2019

Final Toxicological Profiles for TCE, PERC Published

​Final toxicological profiles for the metal degreasing solvents tetrachloroethylene (PERC) and trichloroethylene (TCE) are now available from the Agency for Toxic Substances and Disease Registry. PERC is used as a dry-cleaning agent as well as a solvent. A major use of TCE is to make other chemicals such as HFC-134a, a refrigerant. According to ATSDR, workers in the dry-cleaning industries and those who use metal-degreasing products may be exposed to elevated levels of PERC. Workers at facilities that use TCE for metal degreasing may also be exposed to higher levels of that substance.

ATSDR states that breathing high levels of PERC for a brief period may cause health effects such as dizziness or drowsiness, headache, and incoordination, and higher levels of exposure may cause unconsciousness and death. Longer-term exposure to low levels of PERC may cause changes in mood, memory, attention, reaction time, and vision, the agency says. In addition, some studies in humans suggest that exposure to PERC might lead to an increased risk of bladder cancer, multiple myeloma, or non-Hodgkin’s lymphoma.

Health effects from exposure to high levels of TCE can cause cardiac arrhythmias, liver damage, and evidence of kidney damage. According to ATSDR, skin contact with concentrated solutions of TCE can cause skin rashes, and there is some evidence that occupational exposure to TCE may cause scleroderma—a chronic autoimmune disease primarily of the skin—in some people. The agency cites “strong evidence” that TCE can cause kidney cancer in people and some evidence for liver cancer and malignant lymphoma related to TCE exposure.

A final risk assessment for TCE published by EPA in 2014 identifies occupational health risks to workers who use the chemical as a degreaser in small commercial shops and as a stain-removing agent in dry cleaning. According to the risk assessment, there are cancer risk concerns for users and bystanders occupationally exposed to TCE when using TCE-containing vapor degreasers and spot cleaners. EPA found that occupational exposures to commercial degreasers show the greatest cancer risk when compared to spot-cleaning exposure scenarios.

In 2016, EPA named both TCE and PERC among the first 10 chemicals it will evaluate for potential risks to human health and the environment under the new Toxic Substances Control Act legislation. As of February 2018, the agency said it was on track to complete the risk evaluations by December 2019, the deadline required by TSCA.

ATSDR toxicological profiles characterize the toxicologic and adverse health effects information for hazardous substances. Each peer-reviewed profile identifies and reviews the key literature that describes a substance's toxicological properties. Information on the health effects by route of exposure, biomarkers of exposure and effect, and methods for reducing toxic effects can also be found in the new toxicological profiles. A full list of toxic substances with published profiles is available on ATSDR’s website.