INDUSTRIAL CHEMICALS – PROBABLE CARCINOGEN (IARC 2A)
Tetrachloroethylene, used commercially since the early 1900s, has been an important chlorinated solvent worldwide. Tetrachloroethylene is a colourless, volatile liquid with an ether-like odour. It is also commonly referred to as perchloroethylene or PERC. There are numerous other synonyms and product names; see the Hazardous Substances Data Bank (HSDB) for more information.
The International Agency for Research on Cancer (IARC) has classified tetrachloroethylene as Group 2A, probably carcinogenic to humans, based on sufficient evidence in animals and limited evidence in humans. Exposure to PERC has been associated with bladder cancer in humans. It is known to cause leukemia in rats and liver cancer in mice, as well as kidney cancer in male rats.
Regulations and Guidelines
|Canadian Jurisdictions||OEL (ppm)|
|Canada Labour Code||25
|AB, BC, MB, NB, NL, NS, NU, ON, PE, QC, SK, NT||25
150 [stel] [sk]
|Other Jurisdiction||OEL (ppm)|
|ACGIH 2020 TLV||25
ppm = parts per million
stel = short term exposure limit (15 min. maximum)
sk = easily absorbed through skin
ACGIH = American Conference of Governmental Industrial Hygienists
TLV = threshold limit value
Canadian environmental guidelines and standards*
|Drinking Water Guidelines (Canada, BC) and Standards (ON)||0.01 mg/L||2015-2020
|Quebec Drinking Water Standards||MAC = 0.025 mg/L||2012|
|Manitoba Water Quality Guidelines||MAC = 0.03 mg/L||2011|
|Ontario Ambient Air Quality Criteria||24-hour: 360 µg/m3||2020|
|Government of Canada’s Indoor Air Reference Levels||40 µg/m3 (critical effect: neurotoxicity)||2018|
|Ontario’s Air Pollution – Local Air Quality Regulation||24-hour standard: 360 µg/m3; Prohibited discharge into the air if the concentration of tetrachloroethylene exceeds the standard||2020|
|Quebec’s Clean Air Regulation||1 year limit: 2 µg/m3; Prohibited discharge into the air if the concentration of tetrachloroethylene 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: 250 μg/g
Urban park and high density residential sites: 500 μg/g
Commercial sites: 1,500 μg/g
Industrial sites: 40,000 μg/g
Drinking water: 30 µg/L
Sets vapour standards for the protection of human health:
|Cosmetic Ingredients Hotlist||Not Permitted||2004|
MAC = maximum allowable concentration
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, paragraph ‘a’||1999|
|National Classification System for Contaminated Sites||Rank = “High hazard”||2008|
|Tetrachloroethylene in Dry Cleaning Regulations||PERC must be used in a closed-loop, dry to dry machine
May not be used for spot treatments*
|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|
|CEPA 2003: Solvent Degreasing Regulations||Users of >1,000 kg/yr of PERC for cold or vapour degreasing must comply with the regulations||2011|
* See the compliance guide for further discussion of these and several other rules for use of PERC in dry cleaning.
DSL = domestic substance list
CEPA = Canadian Environmental Protection Act
Tetrachloroethylene was not included in other Canadian government guidelines, standards, or chemical listings reviewed.
Tetrachloroethylene is used primarily for dry cleaning and as an intermediate in chemical synthesis. It is also used as a metal degreaser and in paint removers, printing inks, spot removers, automotive cleaners, and adhesives. PERC is often used in combination with another chlorinated solvent called trichloroethylene (or TCE). Please see the CAREX Profile for TCE for more information.
PERC is used for its ability to remove fats, greases, waxes, and oils from fabric without damaging it. It was introduced to the dry cleaning industry in the 1930s, replacing stain removers commonly used at that time (benzene, gasoline, kerosene, and camphene). Regulations stipulating the use of PERC in dry cleaning businesses and establishing reporting requirements on PERC’s import, recycling, sale, and use, were introduced in 2003 and amended in 2011. The PERC regulations aimed to reduce the use of PERC in dry cleaning to 1,600 tonnes per year. Currently, drycleaners are using approximately 600 tonnes per year.
Canadian regulations passed in 2003 require the metal degreasing industry to decrease consumption of PERC and TCE by 65% between 2007-2021. This reduction level has been met. Currently, 88% fewer consumption units are issued annually compared to when the regulations were passed.
Environmental Exposures Overview
The most important routes of exposure to tetrachloroethylene for the general public are ingesting contaminated water and inhaling ambient air. Improper disposal and releases from dry cleaning facilities and landfills can lead to groundwater contamination and potential environmental exposures.
Between 1994 and 2007, several provinces monitored water supplies for PERC; it was detected in no more than 4% of samples, and only one sample from all provinces contained concentrations greater than 10 micrograms/L. Tetrachloroethylene has also been found in samples of Canadian drinking water. CAREX Canada’s environmental estimates indicate that PERC concentrations in Canadian drinking water do not result in an increased cancer risk (moderate data quality).
The general public may be exposed to PERC by frequenting or living near dry cleaning businesses or via contact with freshly dry cleaned clothing. There is evidence to suggest that family members of workers employed at dry cleaning facilities are more exposed to PERC than the general population. CAREX Canada estimates that PERC levels in outdoor air do not result in an increased risk of cancer (high data quality). However, our estimates indicate that PERC concentrations in indoor air do result in an increased risk of cancer (low to moderate data quality).
PERC has been detected in dairy products, meats, oils and fats, beverages, fruits and vegetables, bread, fish, shellfish, and marine mammals. CAREX Canada estimates that PERC levels in food and beverages do not result in an increased risk of cancer in Canada (very low data quality).
Searches of Environment Canada’s National Pollutant Release Inventory (NPRI) and the US Household Products Database yielded the following results on current potential for exposure to PERC in Canada:
NPRI and US Household Products Database
|Substance name: ‘Tetrachloroethylene’|
|Released into Environment||115 t||plastic product manufacturing, other chemical product manufacturing, waste treatment and disposal, textile and fabric finishing and fabric coating (28 facilities)|
|Disposed of||133 t|
|Sent to off-site recycling||125 t|
|US Household Products 2015|
|Search Term||Quantity||Product Type|
|‘Tetrachloroethylene’||37||Auto brake cleaners (17), adhesives (8), lubricants (4), auto degreaser (3), auto cooling cleaner (1),engine dryer (1), silver polish (1), carpet stain removers (1), fabric protectant (1)|
t = tonne
For more information, see the environmental exposure estimate for tetrachloroethylene.
Occupational Exposures Overview
Inhalation is the most important route of occupational exposure to tetrachloroethylene.
CAREX Canada estimates that approximately 11,000 Canadians are exposed to PERC in their workplaces. The largest industrial groups exposed include dry cleaning and laundry services, printing and related support activities, and traveller accommodation. The largest occupational groups exposed to tetrachloroethylene include dry cleaning, laundry and related occupations, printing press operators, metalworking and forging machine operators, and labourers in metal fabrication. Workers performing metal degreasing, producing fluorocarbons, and producing chemicals are also at risk of exposure to
For more information, see the occupational exposure estimate for tetrachloroethylene.
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