Fact sheet: 1,1,1-trichloroethane

From: Public Services and Procurement Canada

Discover a list of a contaminant's important chemical properties, how it will react in the environment, main sources of contamination related, and a brief overview of health and safety issues.

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General information

CAS number


Molecular formula


Formula weight

133.4 g/mol


Chlorinated aliphatic hydrocarbons (CAH)

Properties (at room temperature where applicable)

Compound properties list
Melting/boiling point -31 °C / 74 °CLiquid
Relative density1.33 g/cm3Sinks in water
Vapour pressure115 mm HgVery volatile
Vapour density4.6Denser than air
Solubility in water1,200 mg/LModerately soluble
Henry's law constant2 x 10-2 atm·m3/molRapid volatilization when dissolved
log Koc (Depending on soil or sediment characteristics)2.0 - 2.8*Moderate adsorption to organic matter

Environmental behaviour

At 20 0C, 1,1,1-trichloroethane is a liquid denser than water and very volatile. Characterized by moderate solubility, it will volatilize rapidly once dissolved and adsorbs moderately to organic matter. During a spill, this compound will mostly evaporate but may also enter into the soil or migrate into a waterway. Once it encounters water (surface or subsurface), 1,1,1-trichloroethane will dissolve or sink until it reaches an impermeable surface. The liquid 1,1,1-trichloroethane that accumulates in a saturated zone will gradually dissolve before partially volatilizing. The adsorbed 1,1,1-trichloroethane in the vadose and saturated zones will rapidly disappear, liberating contamination in either the gaseous or dissolved state. The resulting plumes (gaseous or dissolved) will be relatively large in size.

Health and safety

1,1,1-Trichloroethane should be handled with care as it is toxic.

Principal resources

1,1,1-Trichloroethane is a synthetic chemical that does not occur naturally in the environment. The most common industrial production method is the reaction of hydrochloric acid with vinyl chloride to obtain 1,1-dichloroethane, followed by either thermal or photochemical chlorination. 1,1,1-Trichloroethane was initially developed as a safer solvent to replace other flammable chlorinated solvents. Because it has been classified as an ozone-depleting chemical, its production and uses are now limited. Today, the only significant use of 1,1,1-trichloroethane is in the production of hydrofluorocarbons. Previously 1,1,1-trichloroethane had many industrial and household uses. It was widely used in the production of hydrochlorofluorocarbons (HCFC), as a solvent to remove oil or grease from manufactured materials (such as electrical equipment, motors, electronic components, photographic film, printed circuit boards, fabrics, etc.), or to dissolve other substances such as glues, printing inks and paints. 1,1,1-Trichloroethane was also used as a food and grain fumigant. In the home, it was present in products such as spot cleaners, glues and aerosol sprays. The production of 1,1,1-trichloroethane in Canada in 1988 was 10,000 tons and an additional 6,000 tons were imported. Most of it was used in metal cleaning, particularly the armatures of electric motors, generators, and switchgear and electronic equipment. It was also used in adhesives, as a propellant modifier in aerosols, in several textile finishing operations, as a constituent in various office supplies, as dry lubricants, and as a laboratory solvent. 1,1,1-Trichloroethane is a contaminant frequently found in Canadian waters, particularly near industrialized areas.


Agency for Toxic Substances and Disease Registry (ATSDR). 2006. Toxicological Profile for 1,1,1-Trichloroethane. U.S. Department of Health and Human Services, Public Health Service, Georgia, USA. (Viewed March 2010)

Canadian Council of Ministers of the Environment. 1999. Canadian Water Quality Guidelines for the Protection of Aquatic Life: Chlorinated Ethanes. In: Canadian Environmental Quality Guidelines. Canadian Council of Ministers of the Environment, Manitoba, Canada. (Viewed March 2010)

Montgomery, John H. 2007. Groundwater Chemicals, Desk Reference, Fourth Edition, CRC Press, Taylor and Francis Group, Florida, USA.