State of knowledge report
Environment Australia, 2001
ISBN 0 6425 4739 4
|Synonyms:||Perchloroethylene; PERK; PERC; ethylene tetrachloride; tetrachloroethene; 1,1,2,2-tetrachloroethylene; carbon dichloride; perchlor; tetrachloroethane; carbon bichloride; perk|
Tetrachloroethylene is a colourless liquid solvent. Although it is a liquid at room temperature, some will evaporate giving a sweet ether like odour.
Melting point: -22.3°C
Boiling point: 121.1°C
Specific gravity: 1.623
Vapour pressure: 5.8
Tetrachloroethylene is nonflammable and mostly insoluble in water.
The largest user of tetrachloroethylene is the dry-cleaning industry. Tetrachloroethylene constitutes a large percentage of all dry-cleaning fluid used. Textile mills, vapour degreasers and metal cleaning operations, and rubber coatings also use tetrachloroethylene. It can be added to solvent soaps, printing inks, adhesives, sealants, polishes, lubricants and silicones.
The primary sources of tetrachloroethylene emissions are the industries that manufacture it or use it in production. Some of the industries that use it in production are dry-cleaners, the chemical industry, rubber manufacturers, heavy equipment manufacturers (for degreasing), electroplating facilities (for degreasing), pulp and paper manufacturers (for de-inking paper), and ink manufacturers. Emissions are to the air unless there is a spill.
Diffuse sources, and point sources included in aggregated emissions data
Other possible emitters of tetrachloroethylene are degreasing operations; paint, varnish and lacquer removal; and consumer products containing tetrachloroethylene. These are emissions to the air unless there is a spill.
Tetrachloroethylene does not occur naturally in the environment.
There are no major mobile sources, although it is possible to have emissions from clothes being transported from the dry-cleaners.
Consumer products that may contain tetrachloroethylene
Products include aerosol paints, agricultural chemicals, automotive chemicals, furniture polish and cleaners, hard surface cleaners, rug, carpet and upholstery cleaners, lubricating greases and oils, paint and varnish removers and thinners, textile finishes, typewriter correction fluids and waterproofing compounds.
How might I be exposed to tetrachloroethylene?
Workers in the industries that use or produce tetrachloroethylene are at risk of exposure. Consumers can be exposed to tetrachloroethylene by exposure to air from production and processing facilities using tetrachloroethylene, or by drinking contaminated water. Consumers may also be exposed to tetrachloroethylene when using consumer products containing tetrachloroethylene, by spending time in dry-cleaning facilities that use tetrachloroethylene or by bringing dry-cleaned clothes into their homes.
By what pathways might tetrachloroethylene enter my body?
Tetrachloroethylene evaporates quickly, so the most common exposure is from breathing contaminated air. It may also enter the body if we eat or drink contaminated food or water. It does not pass through the skin.
National Occupational Health and Safety Commission (NOHSC):
- TWA (eight-hour time weighted average) exposure limit in the workplace: 50 ppm (ppm) (340 mg/m³)
- STEL (short-term exposure limit) (15 minutes): 150 ppm (1020 mg/m³).
Australian Drinking Water Guidelines (NHMRC and ARMCANZ 1996):
- Maximum of 0.05 mg/L (ie 0.00005 g/L).
What effect might tetrachloroethylene have on my health?
In high concentrations, in air, with closed or poorly ventilated areas, single exposures to tetrachloroethylene may cause central nervous system effects leading to dizziness, headache, sleepiness, confusion, nausea, difficulty in speaking or walking, and possibly unconsciousness and death. It is a narcotic at high levels. Adverse liver and kidney effects have been observed in workers with long-term exposure to tetrachloroethylene. Tetrachloroethylene will also defat the skin, causing irritation and dryness. It is classified by the NOHSC as a Category 3 carcinogen (substance that causes concern for humans owing to possible carcinogenic effects but in respect of which the available information is not adequate for making a satisfactory assessment).
Tetrachloroethylene enters the air during production, use and transportation. In the air, it will break down into other chemicals (phosgene, a toxic chemical, and chloroacetylchlorides) in a few weeks to a few months. Tetrachloroethylene and its products of degradation contribute to photochemical smog. Most tetrachloroethylene is released to the air, but when released to the soil it will either evaporate or leach into the groundwater (bores). It will quickly evaporate if released to surface water. In soil and water, bacteria will break it down, very slowly. In the soil and subsurface water it may last for months to years.
Industrial emissions of tetrachloroethylene can produce elevated concentrations in the atmosphere around the source. Most releases are to the air; releases to the soil and water quickly evaporate to the air. Since it does not bind to soil well, tetrachloroethylene that makes its way into the ground and does not evaporate may move through the ground and enter groundwater (bore water). Tetrachloroethylene can be transported on clothes that have recently been to the dry-cleaners.
There are no national guidelines.
What effect might tetrachloroethylene have on the environment?
Tetrachloroethylene will exist as a gas if released to the atmosphere. It dissolves only slightly when mixed with water. It also evaporates from soil and water when they are exposed to the air. In the air it reacts to form other chemicals, in several weeks. It has moderate toxicity to aquatic life in both the short and long terms. Chronic and acute effects on plants, birds or land animals have not been determined, but appear to be low. Tetrachloroethylene bioaccumulates to a limited extent. The concentration of tetrachloroethylene in the tissues of fish is expected to be somewhat higher than its concentration in the water from which the fish was taken.
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