Toxicity Profiles

RAGs A Format for 1,1,1-Trichloroethane - CAS Number 71556

1,1,1-Trichloroethane is a colorless liquid with a sharp, sweet odor that does not occur naturally in the environment. Even though it is usually found as a liquid, it evaporates quickly and becomes a vapor. 1,1,1-Trichloroethane is found in many common products such as glue, paint, industrial degreasers, and aerosol sprays. 1,1,1-trichloroethane will no longer be made in the United States due to its effects on the ozone layer.

Breathing air containing high levels of 1,1,1-trichloroethane for a short time may cause dizziness, light-headedness, and loss of balance. These symptoms disappear if fresh air is inhaled. Breathing much higher levels may cause unconsciousness, low blood pressure, and loss of heartbeat. The effects of breathing 1,1,1-trichloroethane for a long time are not known. In animals, such as rats and dogs, exposure to high levels damages the breathing passages, affects the nervous system, and causes mild effects on the liver. After pregnant rats or rabbits were exposed to 1,1,1-trichloroethane, effects on the offspring, such as delayed development and changes in the setting of the bone structure, were usually only seen at levels that were toxic to the mother. It is not known whether this chemical affects human reproduction or development. There are no human studies to determine whether harmful health effects occur from eating food or drinking water contaminated with 1,1,1-trichloroethane. Placing large amounts in an animal’s stomach has caused effects on the nervous system, mild liver damage, unconsciousness, and even death. If skin comes into contact with 1,1,1-trichloroethane, some irritation may occur. Studies in animals have shown that skin contact may affect the liver and very large amounts may cause death.

No information is available to show that 1,1,1-trichloroethane causes cancer. Oral bioassays were inconclusive and inhalation studies were negative. No epidemiological data for 1,1,1-trichloroethane and inadequate carcinogenicity data for animals place the chemical in the United States Environmental Protection Agency's weight-of-evidence group D, not classifiable as to human carcinogenicity.

The following is a presentation of the toxicity information associated with 1,1,1-Trichloroethane.

• The Oral Chronic Reference Dose is 2.00E-01 (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 Reitz et al. study from 1988.
• The Oral Chronic Reference Dose study target organ is liver.
• The Oral Chronic Reference Dose study critical effect is toxivity.

• The Inhalation Chronic Reference Concentration is 2.20E+00 (mg/m³).
• The Inhalation Chronic Reference Concentration has a modifying factor of 1.
• The Inhalation Chronic Reference Concentration has an uncertainty factor of 90.
• The Inhalation Chronic Reference Concentration is based on the Rosengren et al. study from 1985.
• The Inhalation Chronic Reference Concentration study target organs are liver and brain.
• The Inhalation Chronic Reference Concentration study critical effects are damage and injury.
• The overall confidence in the Inhalation Chronic Reference Concentration is low to medium.

• The Dermal Chronic Reference Dose is 1.80E-01 (mg/kg-day).
• The Dermal Chronic Reference Dose is based on a gastrointestinal absorption factor of 0.9000.