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CAS No. 79-01-6

Photo: Wikimedia Commons Photo^[1]

IARC Monograph Vol. 63, 1995 (Group 2A)

General Information

Trichloroethylene is a clear liquid at room temperature with a sweet, chloroform-like odour.^[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]

How did CAREX choose this agent for review?

Regulations and Guidelines

Occupational Exposure Limits (OEL)

Canadian Jurisdictions	OEL (ppm)
Canada Labour Code	10 25 [stel]
BC, MB, ON, NL, PE, NS	10 25 [stel]
AB, NB, SK	50 100 [stel]
QC	50 200 [stel]
NT, NU, YT	100 150 [stel]
Other Jurisdiction	OEL (ppm)
ACGIH 2012 TLV	10 25 [stel]

ppm = parts per million

stel = short term exposure limit (15 min. maximum)

Canadian Environmental Guidelines

Jurisdiction	Limit	Year
Canadian Drinking Water Guidelines	0.005	2010^[6]

Trichloroethylene was not included in other Canadian government environmental guidelines reviewed.^[7,14,15]

Canadian Agencies/Organizations

Agency	Designation/Position	Year
Health Canada	DSL – low priority substance (already risk managed)	2006^[8]
CEPA	Schedule 1, paragraphs ‘a’ and ‘c’ (human health)	1999^[9]
CEPA 1999: Solvent Degreasing Regulations	Users of >1,000 kg/yr of TCE for cold or vapour degreasing must comply with these regulations	2003^[10]

Trichloroethylene was not included in other Canadian government chemical listings reviewed.^[16]

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]

Canadian Production and Trade

Production and Trade

Activity	Quantity	Year
Canadian Production	N/A [Ceased in 1985]	1993^[11]
Domestic Consumption	2,600 t	2004 (forecasted)^[12]
Export: Mainly to US and Kyrgyzstan	24 t of ‘trichloroethylene’	2009^[17]
Import: Mainly from US and UK	708 t of ‘trichloroethylene’	2009^[17]

t = tonne

Occupational Exposures

Inhalation is the most important route of occupational exposure to trichloroethylene.^[3] Workers involved in the degreasing of metals are the most heavily exposed occupational group.^[3]

The main industrial groups that use trichloroethylene for degreasing purposes are manufacturers of furniture and fixtures, fabricated metal products, electrical and electronic equipment, and transport equipment.^[5]

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]

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]

Trichloroethylene can be formed in groundwater by the breakdown of tetrachloroethylene.^[11]

Searches of environmental and consumer product databases yielded the following results on current potential for exposure to trichloroethylene in Canada:

NPRI and US Household Products Database

NPRI 2010^[18]
Search term: ‘trichloroethylene'
Category	Quantity	Industry
Released into Environment	62 t	Aerospace parts and products manufacturing, aircraft servicing, metal servicing, chemical manufacturing (49 companies)
Disposed of	2.9 t
Sent to off-site recycling	27 t

US Household Products 2010^[19]
Search Term	Quantity	Product Type
'trichloroethylene'	12	Cleaners/degreasers, vehicle undercoating, adhesives, cleaners, sealants (hobby use), and toner enhancer