U.S. EPA Contaminated Site Cleanup Information (CLU-IN)

U.S. Environmental Protection Agency
U.S. EPA Technology Innovation and Field Services Division

Dense Nonaqueous Phase Liquids (DNAPLs)


Halogenated Alkanes


Human Health Toxicity

The production of trichlorofluoromethane (TCFM, also called Freon-11 or CFC-11) has been banned in the United States since 1996; however, the compound had wide industrial and consumer use before that date. A world-wide average background concentration of 0.25 parts per billion of TCFM in ambient air has been calculated, which suggests that the general population might be exposed via inhalation (Lewis 1997).

TCFM is absorbed rapidly via inhalation in humans and laboratory animals. No studies are available on the absorption of the compound by ingestion or dermal contact, although it is assumed that the physical chemistry of the compound would enable absorption by either of these routes. Once absorbed, the majority of TCFM is excreted unchanged in exhaled air. Animal studies suggest that although TCFM is taken up by brain, lung, liver, heart, and reproductive organs, the overall amount is small, totaling less than one percent of the administered dose. Little TCFM is metabolized.

Case reports of accidental or intentional inhalation of TCFM show that the compound is acutely toxic to humans. The abuse of aerosols containing TCFM as a propellant has resulted in death from cardiac arrest, and in some cases, acute pulmonary congestion. Inhalation of the compound caused tremors, convulsions, shallow respiration, and death in laboratory rodents. These effects can be attributed to the action of the compound on the central nervous system; however, studies that employed several different species as test subjects indicate that TCFM also exerts toxic effects on the heart, producing cardiac arrhythmias, tachycardia, a reduction on the ability of cardiac muscle to contract, and a reduction in blood pressure (Lewis 1997).

Chronic oral exposure of rats and mice to TCFM did not result in tumor development under the conditions of the study. Similarly, a chronic inhalation carcinogenicity study did not identify an increase in tumor frequency.

Exposure of pregnant rats and rabbits to a mixture of CFC-11 and CFC-12 did not cause developmental toxicity. No data are available on the exposure of pregnant rodents to TCFM alone. Likewise, no data are available that describe the effects of TCFM on human reproduction or development.

The majority of in vitro genotoxicity assays give negative results for TCFM.


Public Health Goal for Trichlorofluoromethane (FC-11) in Drinking Water Adobe PDF Logo
Lewis, D.
California Environmental Protection Agency, Office of Environmental Health Hazard Assessment, Pesticide and Environmental Toxicology Section, 27 pp, 1997

Trichlorofluoromethane (CASRN 75-69-4)
U.S. EPA, Integrated Risk Information System (IRIS).

Ecological Toxicity

No data were found on the ecological toxicity of TCFM.