Atmosphere

Air toxics and indoor air quality in Australia

State of knowledge report
Environment Australia, 2001
ISBN 0 6425 4739 4

Part C: Factsheets (continued)

Trichloroethylene

Substance name: Trichloroethylene
CASR number: 79-01-6
Molecular formula: C2HCl3
Synonyms: Ethinyl trichloride; acetylene trichloride; ethylene trichloride ; 1,1,2-trichloroethylene; tri; TCE; trichloroethene; trichloran; trichloren;

Physical and chemical properties

Trichloroethylene is a colourless, liquid with a sweet odour, and a sweet burning taste.

Melting point: -86°C
Boiling point: 86.7°C
Vapour density: 4.53
Specific gravity: 1.456
Vapour pressure: 7.7 kPa
Flashpoint: None (according to ATSDR 1993)
Auto-ignition temperature: 410°C
Flammability limits: 8.0–10.5% in air at 25°C

Trichloroethylene is nonflammable. It is slightly soluble in water, and soluble in most other organic solvents.

Common uses

Trichloroethylene is primarily used as a solvent to remove grease from metal parts. As a solvent or as a component of solvent blends, it is used in adhesives, lubricants, paints, varnishes, paint strippers, carpet shampoos and waterproofing agents. The textile industry uses it to scour cotton, wool and other fabrics, and in waterless dyeing and finishing.

Sources of emissions

Point sources

The primary sources of trichloroethylene emissions are at shipping terminals during the handling of imported trichloroethylene and in the industries that use it, including the chemical industry, rubber manufacturers, heavy equipment manufacturers, iron and steel manufacturers, pulp and paper manufacturers (for de-inking paper), and the manufacturers of paints, inks, varnishes and lacquers. These are emissions to the air unless there is a spill.

Diffuse sources, and point sources included in aggregated emissions data

Trichloroethylene may also be emitted during degreasing operations, cold cleaning, commercial and household painting, paint, varnish and lacquer removal, and from consumer products containing trichloroethylene. These are emissions to the air unless there is a spill.

Natural sources

Trichloroethylene does not occur naturally in the environment.

Mobile sources

There are no mobile sources.

Consumer products that may contain trichloroethylene

Aerosol paints, adhesive glues, lubricating and oils, automotive chemicals, paint and varnish removers and thinners, typewriter correction fluids and waterproofing products.

Health effects

How might I be exposed to trichloroethylene?

Workers in the industries that use or produce trichloroethylene are at risk of exposure. Consumers can be exposed to trichloroethylene by exposure to air from processing facilities using trichloroethylene, or by drinking contaminated water. Consumers may also be exposed to trichloroethylene when using products containing the substance, especially if there is not good ventilation, or by skin contact. Because trichloroethylene is used in many consumer products, short-term indoor concentrations may be elevated above the levels considered safe for workers.

By what pathways might trichloroethylene enter my body?

Trichloroethylene will enter the body if we breathe in contaminated air or ingest contaminated water. It can also pass through the skin.

Health guidelines

National Occupational Health and Safety Commission (NOHSC):

Trichloroethylene is listed in Schedule 6 of the Standard for the Uniform Scheduling of Drugs and Poisons except when it is used for therapeutics, in which case it is listed in Schedule 4.

What effect might trichloroethylene have on my health?

Trichloroethylene is a central nervous system depressant and has been used in the past as an anaesthetic for surgery. Some people intentionally inhale it for its narcotic properties. Exposure to moderate amounts of trichloroethylene may cause headaches, loss of balance, and tremors. Larger exposures will cause dizziness or sleepiness, and at very high levels may cause unconsciousness. Very large exposures may cause irreversible cardiac problems, nerve and liver damage, and death. Trichloroethylene is mildly irritating to the eyes, nose and throat. Chronic (long-term) exposures to trichloroethylene have been shown to cause nausea, intolerance to fatty foods, respiratory irritation, renal (kidney) toxicity, and immune system depression. Alcohol consumption increases the toxicity of trichloroethylene and may cause 'degreaser's flush', which appears as red blotches on the skin. The International Agency for Research on Cancer has classified trichloroethylene as a 'probable human carcinogen'. Trichloroethylene is classified by the NOHSC as a Category 2 carcinogen (substance that should be regarded as if it is carcinogenic to humans).

Environmental effects

Environmental fate

Trichloroethylene enters the air during use and transport. In the air it will break down into other chemicals (phosgene, formyl chloride, and chlorine atoms), which leads to the creation of hydrochloric acid) in 6–40 days. When released to the soil, it will either evaporate or leach into the groundwater (bore water). It will also quickly evaporate if released to surface water. According to the World Health Organization, trichloroethylene is widely distributed in surface water, rainwater, and bore water. In soil and water, bacteria break it down. In water, it will break down in 2–10 days. It does not deposit on the bottom of rivers or lakes.

Environmental transport

Industrial emissions of trichloroethylene can produce elevated concentrations in the atmosphere around the source, but because of its short life-expectancy in the atmosphere it is expected to be confined to the local area within which it is emitted. Since it does not bind to soil well, trichloroethylene that makes its way into the ground may move through the ground and enter groundwater (bore water).

Environmental guidelines

There are no national guidelines.

What effect might trichloroethylene have on the environment?

Trichloroethylene will exist as a gas if released to the atmosphere. It dissolves when mixed with water. In the air it reacts to form other chemicals; in water and soil, bacteria break it down. It has moderate acute (short-term) toxicity to aquatic life. It has moderate chronic (long-term) toxicity to aquatic life. Chronic and acute effects on plants, birds and land animals have not been determined. Trichloroethylene bioaccumulates to a limited extent. The concentration of trichloroethylene in the tissues of fish is expected to be higher than the concentration of trichloroethylene in the water from which the fish was taken.

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