INDUSTRIAL CHEMICALS – KNOWN CARCINOGEN (IARC 1)
Trichloroethylene is a clear liquid at room temperature with a sweet, chloroform-like odour. Produced commercially since the 1920s, trichloroethylene has been used as a solvent and degreaser. Trichloroethylene is related to another chlorinated solvent, tetrachloroethylene (also called perchloroethylene or PERC). Trichloroethylene may also be referred to as trichloroethene or TCE. There are numerous other synonyms and product names; see the Hazardous Substances Data Bank (HSDB) for more information.
Trichloroethylene has been classified by the International Agency for Research on Cancer (IARC) as Group 1, a known human carcinogen, with a well established link to kidney cancer. Epidemiologic studies also found limited evidence for associations between TCE exposure and non-Hodgkin lymphoma and liver cancer.
Additional adverse health effects associated with low to moderate inhalation exposure to trichloroethylene range from headaches and dizziness to nerve damage. Acute exposures may damage the kidneys and liver, and cause arrhythmias. Skin irritation following dermal exposure has also been reported.
Regulations and Guidelines
Occupational exposure limits (OEL)[4,5,6,7,8,9,10,11,12,13,14,15,16,17,18]
|Canadian Jurisdictions||OEL (ppm)|
|Canada Labour Code||10
|BC, MB, ON, NL, PE, NS||10
|AB, NU, SK, NB, NT||50
|Other Jurisdiction||OEL (ppm)|
|ACGIH 2020 TLV||10
ppm = parts per million
stel = short term exposure limit (15 min. maximum)
ACGIH = American Conference of Governmental Industrial Hygienists
TLV = threshold limit value
Canadian environmental guidelines and standards*
|Drinking Water Guidelines (Canada, BC, MB) and Standards (ON, QC)||0.005 mg/L||2005-2020
|Saskatchewan’s Drinking Water Standards||0.05 mg/L||2020|
|Ontario Ambient Air Quality Criteria||Annual: 2.3 μg/m3
24 hour: 12 μg/m3
|Ontario’s Air Pollution – Local Air Quality Regulation||24-hour standard: 12 µg/m3;Prohibited discharge into the air if the concentration of trichloroethylene exceeds the standard||2020|
|Quebec’s Clean Air Regulation||1 year limit: 0.4 µg/m3;Prohibited discharge into the air if the concentration of trichloroethylene exceeds the standard||2011|
|BC’s Contaminated Sites Regulation, BC Reg 375/96||Sets soil standards for the protection of human health:
Agricultural and low density residential sites: 20 μg/g
Urban park and high density residential sites: 40 μg/g
Commercial sites: 150 μg/g
Industrial sites: 3,500 μg/g
Drinking water: 5 µg/L
Sets vapour standards for the protection of human health:
μg/m3 = micrograms per cubic metre
μg/g = micrograms per gram
μg/L = micrograms per litre
*Standards are legislated and legally enforceable, while guidelines (including Ontario ambient air quality criteria) describe concentrations of contaminants in the environment (e.g. air, water) that are protective against adverse health, environmental, or aesthetic (e.g. odour) effects
|Health Canada||DSL – low priority substance (already risk managed)||2006|
|CEPA||Schedule 1, paragraphs ‘a’ and ‘c’ (human health)||1999|
|CEPA 1999: Solvent
|Users of >1,000 kg/yr of TCE for cold or vapour degreasing must comply with these regulations||2003|
|National Classification System for Contaminated Sites||Rank = “High hazard”||2008|
|Environment Canada’s National Pollutant Release Inventory||NPRI Part (Threshold Category): 1A, Reportable to NPRI if manufactured, processed, or otherwise used at quantities greater than: 10 tonnes||2016|
DSL = domestic substance list
CEPA = Canadian Environmental Protection Act
Trichloroethylene was not included in other Canadian government guidelines, standards, or chemical listings reviewed.
Trichloroethylene is used primarily to degrease metals in automotive and metal industries. Another important use is as a feedstock material to produce other chemicals, such as fluorinated hydrocarbons and polymers. Trichloroethylene is also used to: produce adhesives and copolymers; clean electronic components; perform petroleum industry processes involving refining catalysts, paint removers, coatings, and vinyl resins; and act as a reagent/solvent in laboratory applications.
As a solvent, trichloroethylene has been used in the past to extract natural fats and oils, spices, hops, and caffeine from food products. It was also used as a dry cleaning solvent, but since the 1950s when tetrachloroethylene gained popularity, this use declined. Use as a spot treatment in the textile industry, however, continued into the 1990s at least.
Environmental Exposures Overview
The primary route of exposure to trichloroethylene for the general public is inhaling indoor air.[34,36] Minor sources of exposure include food, drinking water, and outdoor air. Trichloroethylene in indoor air likely comes from volatilized water sources (e.g. from showering), as well as from household products containing the solvent. Elevated concentrations in indoor air may also occur in homes that are built above groundwater contaminated with trichloroethylene. Trichloroethylene can be formed in groundwater when tetrachloroethylene breaks down.
Recent surveys of trichloroethylene levels in Canadian food products are not available. However, given that trichloroethylene has been banned from food preparation since 1977, these levels are expected to be negligible.
Most trichloroethylene that is used is expected to eventually enter the atmosphere. Point sources that may create higher, localized environmental levels of trichloroethylene include metal degreasing operations, sewage treatment plants, textile mills, landfills, incinerators, and septic tanks.
Searches of Environment Canada’s National Pollutant Release Inventory (NPRI) and the US Consumer Product Information Database yielded the following results on current potential for exposure to trichloroethylene in Canada:
NPRI and US Consumer Product Information
|Substance name: ‘Trichloroethylene’|
|Released into Environment||46 t||Manufacturing of plastic, aerospace, metal, and chemical products, non-residential building construction, waste treatment and disposal, pulp and paper mills (12 facilities)|
|Sent to off-site recycling||7.4 t|
|US Consumer Products 2016|
|Search Term||Quantity||Product Type|
|‘Trichloroethylene’||13||Cleaners/degreasers, vehicle undercoating, adhesives, sealants, and toner enhancer|
t = tonne
Occupational Exposures Overview
Inhalation and dermal contact are the most important routes of occupational exposure to trichloroethylene.
CAREX Canada estimates that approximately 7,600 Canadians are exposed to trichloroethylene in their workplaces. The largest industrial groups exposed are personal and household goods repair and maintenance, fabricated metal product manufacturing, and printing and related support activities. The largest occupational groups exposed are industrial painters, coaters, and metal finishing process operators; tailors, dressmakers, furriers and milliners; metalworking and forging machine operators; and labourers in metal fabrication. Many of these occupations involve metal degreasing; workers who degrease metals tend to be the most heavily exposed occupational group.
For more information, see the occupational exposure estimate for trichloroethylene.
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