Trichloroethylene

 

• General Information

• Regulations and Guidelines

• Main Uses

• Canadian Production and Trade

• Occupational Exposures

• Environmental Exposures

• Exposure Reduction

• Sources

 

General Information

 

Trichloroethylene is a clear liquid at room temperature with a sweet, chloroform-like odor.[2] Produced commercially since the 1920s, trichloroethylene has been used as a solvent and degreaser.[3] Trichloroethylene is related to another chlorinated solvent,  tetrachloroethylene (also called perchloroethylene or PERC). Trichloroethylene may also be referred to as trichloroethene or TCE.[2]

 

There are numerous other synonyms and product names; see HSDB for more information.[4]

 

Trichloroethylene has been classified by IARC as Group 1, carcinogenic to humans, with a well-established link to kidney cancer.[3]Epidemiologic studies also found limited evidence associating TCE exposure with non-Hodgkin lymphoma (NHL) and liver cancer.[3]

 

Additional adverse health effects associated with low to moderate inhalation exposure to trichloroethylene range from headaches and dizziness to nerve damage.[2] Acute exposures may cause damage to the kidneys and liver and arrhythmias.[2] Skin irritation following dermal exposure has also been reported.[2]

 

Main Uses

 

Trichloroethylene is used primarily for the degreasing of metals in the automotive and metal industries.[11] In 1995, the degreasing of metals accounted for 80-90% of trichloroethylene use worldwide.[3]

 

Other uses include the production of adhesives and copolymers, the cleaning of electronic components, petroleum industry processes involving refining catalysts, paint removers, coatings and vinyl resins, and in laboratory reagent/solvent applications.[12]

 

Trichloroethylene has been used in the past as a solvent to extract natural fats and oils, spices, hops, and caffeine from food products.[5] It has also been used as a dry cleaning solvent, but since the 1950s this use has been very limited.[3] Use as a spot treatment in the textile industry, however, continued into the 1990’s at least.[13]

 

Occupational Exposures

 

Inhalation is the most important route of occupational exposure to trichloroethylene.[3] CAREX Canada estimates that approximately 9,800 Canadians are exposed to trichloroethylene in their workplaces.

 

The largest industrial groups exposed are metal manufacturing, followed by personal and household goods repair and maintenance.

 

The largest occupational groups exposed are metal product machine operators, plating, metal spraying and related operators, and laborers in metal fabrication. All these occupations involve metal degreasing as a part of their jobs; workers involved in the degreasing of metals tend to be most heavily exposed occupational group.

 

The largest occupational groups exposed are metal product machine operators, plating, metal spraying and related operators, and laborers in metal fabrication. All these occupations involve metal degreasing as a part of their jobs; workers involved in the degreasing of metals tend to be most heavily exposed occupational group.[3]

 

Other important occupations outside the metal industry that may be exposed to trichloroethylene include tailors and dressmakers, upholsterers, and sewing machine operators.

For more information, see CAREX Canada’s occupational exposure estimates for trichloroethylene.

 

Environmental Exposures

 

The primary route of exposure to the general public is inhalation of indoor air.[5,11] Minor sources of exposure include food, drinking water, and outdoor air.[11] TCE in indoor air likely comes from volatilization from water sources (e.g. when showering), as well as from household products containing the solvent.[2]

 

Recent surveys of levels of TCE in food products in Canada are not available, but trichloroethylene has not been allowed in the preparation of foodstuffs since 1977.[11] Older studies have found TCE in a variety of foods including dairy products, meats, oils and fats, beverages, fruits and vegetables. Margarine was found to contain the highest levels of trichloroethylene (440 to 3,600 ppb).[2]

 

Environment and Health Canada estimated that the average Canadian’s daily intake of trichloroethylene is in the range of 0.37 - 0.60 mg/kg of body weight per day.[11] Most trichloroethylene that is used is expected to eventually enter the atmosphere.[11]Trichloroethylene can be formed in groundwater by the breakdown of tetrachloroethylene.[11]

 

Point sources which may cause higher localized environmental levels of TCE include metal degreasing operations, sewage treatment plants, textile mills, landfills, incinerators, and septic tanks.[11]

 

We also recommend exploring the Prevention Policies Directory, a freely-accessible online tool offering information on policies related to cancer and chronic disease prevention. Providing summaries of the policies and direct access to the policy documents, the Directory allows users to search by carcinogen, risk factor, jurisdiction, geographical location, and document type. Click here to learn more about policies specific to trichloroethylene in the Directory.

 

For questions about this resource, please contact a member of the Prevention Team at the Canadian Partnership Against Cancer at primary.prevention@partnershipagainstcancer.ca.

 

Sources

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1. Wikimedia Commons Photo: Trichloroethylene

2. ATSDR Toxicological Profile for trichloroethylene (1997) (PDF)

3. IARC Monograph Working Group (2012) Carcinogenicity of trichloroethylene, tetrachloroethylene, some other chlorinated solvents, and their metabolites

4. Hazardous Substances Data Bank (Search term: 'Trichloroethylene')

5. NTP 13th Report on Carcinogens for Trichloroethylene (2011) (PDF)

6. Health Canada (2014) Guidelines for Canadian Drinking Water

7. Exposure Guidelines for Residential Indoor Air Quality (1987) (PDF)

8. Health Canada’s Prioritization of the DSL (2006)

9. CEPA List of Toxic Substances (1999)

10. CEPA 1999 Solvent Degreasing Regulations

11. Priority Substances List assessment report (CEPA) for trichloroethylene (1993) (PDF)

12. Health Canada (2014) Cosmetic Ingredient Hotlist

13. Health Canada (2013) Food Additives Permitted for Use in Canada

14. Government of Canada (2010) Chemicals Management Plan – List of all Challenge Substances

15. TradeMap (Free subscription required)

16. National Pollutant Release Inventory Facility Search (Substance name: ‘Trichloroethylene')

17. Household Products Database (US)