Toxicity Profiles

RAGs A Format for Tetrachloroethylene - CAS Number 127184

Tetrachloroethylene is a manufactured organic chemical that is widely used for dry cleaning of fabrics and for metal-degreasing. It is also used to make other chemicals and is used in some consumer products. Other names for tetrachloroethylene include perchloroethylene, PCE, and tetrachloroethene. It is a nonflammable liquid at room temperature that evaporates easily into the air and has a sharp, sweet odor.

Tetrachloroethylene is rapidly absorbed by the lungs and the digestive tract, but not through the skin. High concentrations of tetrachloroethylene in the air can cause dizziness, headache, sleepiness, confusion, nausea, difficulty in speaking and walking, unconsciousness, and death. Acute exposure to high concentrations of the chemical (estimated to be greater than 1500 ppm for a 30-minute exposure) may be fatal to humans. Irritation may result from repeated or extended skin contact with Tetrachloroethylene. These symptoms occur almost entirely in work (or hobby) environments due to accidental exposure to high concentrations or intention use of tetrachloroethylene to get a "high". In industry, most workers are exposed to levels lower than those causing obvious nervous system effects. The health effects of breathing air or drinking water with low levels of tetrachloroethylene are not known. Results from some studies suggest that women who work in dry cleaning industries where exposures to tetrachloroethylene can be quite high may have more menstrual problems and spontaneous abortions than women who are not exposed. It is not known, however, if tetrachloroethylene was responsible for these problems because other possible causes were not considered. Results of animal studies, conducted with amounts much higher than those that most humans are exposed to, show that tetrachloroethylene can cause liver and kidney damage.

Epidemiology studies of dry cleaning and laundry workers have demonstrated excesses in mortality due to various types of cancer, including liver cancer, but the data are regarded as inconclusive because of various confounding factors. The tenuous finding of an excess of liver tumors in humans is strengthened by the results of carcinogenicity bioassays, in which tetrachloroethylene, administered either orally or by inhalation, induced hepatocellular tumors in mice. The chemical also induced mononuclear cell leukemia and renal tubular cell tumors in rats. Although U.S. EPA's Science Advisory Board recommended a weight-of-evidence classification of C-B2 continuum (C = possible human carcinogen; B2 = probable human carcinogen), the agency has not adopted a current position on the weight-of-evidence classification. The Department of Health and Human Services (DHHS) has determined that tetrachloroethylene may reasonably be anticipated to be a carcinogen.

The following is a presentation of the toxicity information associated with Tetrachloroethylene.

Noncarcinogenic Health Effects

  • The Oral Chronic Reference Dose is 1.00E-02 (mg/kg-day).
  • The Oral Chronic Reference Dose has a modifying factor of 1.
  • The Oral Chronic Reference Dose has an uncertainty factor of 1000.
  • The Oral Chronic Reference Dose is based on the Buben and O'Flaherty study from 1985.
  • The Oral Chronic Reference Dose study critical effects are hepatotoxicity and weight gain.
  • The overall confidence in the Oral Chronic Reference Dose is medium.

  • The Inhalation Chronic Reference Concentration is 6.00E-01 (mg/m3).
  • The Inhalation Chronic Reference Concentration has a modifying factor of 1.
  • The Inhalation Chronic Reference Concentration has an uncertainty factor of 30.
  • The Inhalation Chronic Reference Concentration is based on the NTP study from 1986.
  • The Inhalation Chronic Reference Concentration study target organ is kidney.
  • The Inhalation Chronic Reference Concentration study critical effect is tubular cell karyomegaly.
  • The overall confidence in the Inhalation Chronic Reference Concentration is medium.

  • The Dermal Chronic Reference Dose is 1.00E-02 (mg/kg-day).
  • The Dermal Chronic Reference Dose is based on a gastrointestinal absorption factor of 1.0000.

Carcinogenic Health Effects

    Tetrachloroethylene cancer toxicity values are taken from California EPA and EPA Region 9. Please see the letter justifying the use of these values. EPA Regions VI and III have adopted these toxicity values as well.

  • The Oral Slope Factor is 5.40E-01 (mg/kg-day)-1.

  • The Inhalation Unit Risk is 5.9E-03 (mg/m3)-1.

  • The Inhalation Slope Factor is 2.07E-02 (mg/kg-day)-1.

  • The Dermal Slope Factor is 5.40E-01 (mg/kg-day)-1.
  • The Dermal Slope Factor is based on a gastrointestinal absorption factor of 1.0000.