INDUSTRIAL CHEMICALS – Possible Carcinogen (IARC 2B)
1,2-Dichloroethane is a clear, colourless, oily liquid with a chloroform-like pleasant odour and volatile properties. It is an important industrial chemical, particularly when used as an intermediate in producing polyvinyl chloride.
1,2-Dichloroethane is classified by the International Agency for Research on Cancer (IARC) as Group 2B, possibly carcinogenic to humans, based on evidence in experimental animals. Studies in mice and rats showed an association between exposure to 1,2-dichloroethane and an increased incidence of tumours at various sites, including the stomach, lung, liver, mammary gland, and uterus. Although excesses of some cancers were observed in epidemiological studies, results specific to 1,2-dichloroethane are inconclusive due to potential exposure to multiple compounds.
Ingestion and/or inhalation exposure to high levels of 1,2-dichloroethane may also cause adverse health effects in the lungs, kidneys, liver, and nervous system.
Regulations and Guidelines
|Canadian Jurisdictions||OEL (ppm)|
|Canada Labour Code||10|
|AB, MB, ON, NL, PE, NB, NS||10|
|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) and Standards (ON, QC, SK**)||0.005 mg/L||2003-2020[20,21,22,23,24]|
|BC’s Contaminated Sites Regulation, BC Reg 375/96||Sets soil standards for the protection of human health:
Agricultural and low density residential sites: 75 μg/g
Urban park and high density residential sites: 150 μg/g
Commercial and industrial sites: 350 μg/g
Drinking water: 5 μg/L
Sets vapour standards for the protection of human health:
|Ontario Ambient Air Quality Criteria||Annual: 0.4 µg/m3
24-hour: 2 µg/m3
|Ontario’s Air Pollution – Local Air Quality Regulation Standards||24-hour: 2 µg/m3; Discharge of 1,2-dichloroethane into the air that leads to levels exceeding the 24-hour standard is prohibited||2020|
*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
** Interim maximum acceptable concentration
|Health Canada||DSL – low priority substance (already risk managed)||2006|
|CEPA||Schedule 1, paragraph ‘c’ (human health)||1999|
|CCME National Classification System for Contaminated Sites||High hazard, potential human carcinogen||2008|
|Environment Canada’s National Pollutant Release Inventory||Reportable to NPRI if manufactured, processed, or otherwise used at quantities greater than 10 tonnes or if released at quantities greater than 1 tonne of 10-tonne total VOC air release||2016|
DSL = domestic substance list
CEPA = Canadian Environmental Protection Agency
CCME = Canadian Council of Ministers of the Environment
1,2-Dichloroethane was not included in other Canadian government guidelines, standards, or chemical listings reviewed.
1,2-Dichloroethane is used primarily to produce vinyl chloride monomer, which is then used to make polyvinyl chloride (PVC). A small quantity of 1,2-dichloroethane is used to produce compounds including ethylenediamines, tri- and tetrachloroethene, aziridines, and various chlorinated solvents used for extracting and cleaning.[2,32]
The use of 1,2-dichloroethane as a lead scavenging agent in gasoline is declining, although the extent of its current use in aircraft fuel is not clear. Historically, 1,2-dichloroethane was used in ore flotation and metal degreasing, as a grain, household and soil fumigant, and as a solvent to clean textiles and process pharmaceuticals.
Environmental Exposures Overview
The main source of exposure to 1,2-dichloroethane for the general population is indoor air.[34,35] 1,2-Dichloroethane has rarely been detected in food and there is low potential for bioaccumulation.[35,36] Exposure may also occur by consuming contaminated water, but because 1,2-dichloroethane evaporates quickly from water into air, this risk is decreased.[2,35]
The main sources of 1,2-dichloroethane emissions in Canada were from its manufacture and distribution, and its use in producing vinyl chloride.[2,35,37] Hazardous waste sites are also a source of emissions.
Under CEPA’s lifecycle management requirements, Dow Chemical Canada Inc’s production and storage locations were monitored from 2001-2004. This monitoring recorded a 34% reduction (3,957 kg) in 1,2-dichloroethane emissions at Dow’s Fort Saskatchewan plant and a 54% reduction (1,253 kg) from the North Vancouver facility.
Ambient air surveys conducted from 1988-1990 in 12 Canadian cities across six provinces found mean levels of 1,2-dichloroethane ranging from 0.07-0.28 µg/m3. The mean concentration of 1,2-dichloroethane from a 1991 national pilot study of residential indoor air (750 residences, 10 provinces) was 1.8 µg/m3. A more recent personal monitoring study conducted in 2005-2006 in Windsor, Ontario, found levels ranging from 0.080-0.265 µg/m3 indoors, and 0.034-0.046 µg/m3 outdoors. Canadians’ total daily intake of 1,2-dichloroethane has been estimated to be 0.43-0.70 µg/kg-body weight/day.
In the past, household products such as cleaning products, pesticides, and carpet/wallpaper glues contained 1,2-dichloroethane.[2,35] Currently, no household products in the U.S. Household Products Database were listed with 1,2-dichloroethane as an ingredient. A search of the National Pollutant Reporting Inventory (NPRI) yielded the following results on current potential for exposure to 1,2-dichloroethane in Canada:
|Substance name: ‘1,2-Dichloroethane’|
|Released into Environment||0.284 t||Chemical manufacturing,
waste treatment and disposal (5 facilities)
|Disposed of||0.047 t|
|Sent to off-site recycling||None|
t = tonne
Occupational Exposures Overview
Inhalation is the most important route of occupational exposure, although there is potential for ingestion and dermal contact.
CAREX Canada estimates that approximately 2,000 Canadian workers are exposed to 1,2-dichloroethane. The largest industrial groups exposed are basic chemical manufacturing followed by warehousing and storage. Other significant industries associated with 1,2-dichloroethane exposures include management, scientific and technical consulting services; remediation and management of waste; and soap, cleaning compound, and toilet preparation manufacturing. The largest exposure groups by occupation are chemical plant machine operators, material handlers, and central control and process operators for petroleum, gas, and chemical processing.
For more information, see the occupational exposure estimate for 1,2-dichloroethane.
- Agency for Toxic Substances and Disease Registry (ATSDR). ToxFAQs Sheet for 1,2-Dichloroethane (2010) (PDF)
- Government of Canada. 1,2-Dichloroethane Document (1987) (PDF)
- World Health Organization (WHO). Water Sanitation and Health: Environmental Levels and Human Exposure
- World Health Organization. Guidelines for Drinking-water Quality. Fourth edition. (2011) (PDF)
- Ministry of the Environment Ontario. Ontario Drinking Water Surveillance Program Summary Report for 2000, 2001, and 2002(PDF)
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