Industrial Chemicals– Possible Carcinogen (IARC 2B)
CAS No. 100-41-4
Photo: Wikimedia Commons
IARC Monograph Vol. 77, 2000 (Group 2B)
Ethylbenzene is a volatile organic compound (VOC) in the ‘BTEX’ substance group which includes benzene, toluene, ethylbenzene and xylene. Ethylbenzene is a colourless liquid that smells similar to gasoline. It exists naturally in petroleum, and is also an industrial chemical with a variety of uses.
Ethylbenzene may be referred to as phenylethane or EB. See the HSDB for other synonyms and more information.
Ethylbenzene has been classified by IARC as Group 2B, possibly carcinogenic to humans. Available epidemiological studies do not provide adequate evidence of carcinogenicity in humans, however animal studies show an increase in lung and liver cancers in mice and kidney cancers in rats exposed to ethylbenzene.
Additionally, short term exposure to high concentrations of ethylbenzene can cause eye and throat irritation. Chronic exposure may also cause haematological effects and damage to the inner ear.
stel = short term exposure limit (15 min. maximum)
Canadian Environmental Guidelines
Canadian Drinking Water Guidlines
< 0.0024 mg/L
Ethylbenzene was not included in other Canadian government environmental guidelines reviewed.[7,13,14]
DSL – high priority substance with greatest potential for exposure
*Under CEPA 1999, ethylbenzene was chosen for screening to investigate potential for the substance to enter the environment in harmful amounts. A State of the Science Report was commissioned to provide a profile of current use and exposure across Canada, including information up until May 2005. The compound was still undergoing a risk assessment as of August 2011.
Ethylbenzene was not included in other Canadian government chemical listings reviewed.[9,15]
Pure ethylbenzene is used almost exclusively as a precursor for styrene production.
Ethylbenzene is often found in mixed xylene solvents (at up to 25%) which are used in paints, coatings, lacquers, varnishes, adhesives, inks, insecticides, cleaning materials, dyes, perfumes, pharmaceuticals, rubber and plastics.[4,5,12] It is also used as a solvent and in the production of various other chemicals, and is also found in asphalt and naphtha, tobacco products, and gasoline (at up to 15%).
Canadian Production and Trade
Almost all ethylbenzene in Canada is produced by the alkylation of benzene for the industrial production of styrene, although small amounts may be marketed for solvent use. Thus, ethylbenzene demand follows the same market fluctuations as styrene, and was generally strong from 2002-2006.
As of 2006, there were 2 Canadian companies producing ethylbenzene (in Sarnia, Ontario and Scotford, Alberta).
Production and Trade
2006 (forecasted in 2004)
2006 (forecasted in 2004)
Export: Mainly to US
421 t of ‘ethylbenzene’
Import: Mainly from US
138 t of ‘ethylbenzene’
t = tonne
Inhalation is the most important route of occupational exposure.
CAREX Canada estimates that approximately 208,000 Canadians are exposed to ethylbenzene in their workplaces. Industrial groups that typically operate in or around areas where combustion products accumulate tend to be at higher risk for ethylbenzene exposure. The largest exposed industrial groups are automotive repair and maintenance, public administration (firefighters), taxi and limousine services, and automotive dealers.
In terms of exposures by occupations, the largest exposed groups tend to be automotive service technicians, truck and bus mechanics, firefighters, and professional drivers (e.g. taxi, limousine, or truck drivers, chauffeurs).
Occupational exposure to ethylbenzene can also occur during the production and handling of ethylbenzene or during the use of mixed xylenes, which are used as solvents for paints, inks, lacquers, and in rubber and plastic production. Exposures can also occur in coal and petroleum refining and in the production and handling of gasoline and bitumens.
Although ethylbenzene is used in styrene production, exposure is expected to be low since the process is typically enclosed. Low levels of ethylbenzene, however, were reported in the 1990s as a by-product of styrene production.
According to Health Canada, the primary source of ethylbenzene exposure is indoor air. CAREX Canada estimates that ethylbenzene levels in indoor air are sources of elevated cancer risk (high data quality).
Ethylbenzene has also been detected in outdoor air, drinking water, soil and food. CAREX Canada estimates that ethylbenzene levels in outdoor air (high data quality), drinking water (moderate data quality), and food and beverages (very low data quality) are not significant sources of cancer risk.
Sources of atmospheric ethylbenzene include petroleum and coal refining, evaporation from solvents and thinners, and vehicle emissions. Tobacco and wood smoke also contain ethylbenzene.
In the environment, ethylbenzene typically exists as a vapour. It can also bind to some soils and clay minerals, but tends to be mobile enough to be of concern for groundwater contamination. Sources of soil and groundwater contamination include leaking underground gasoline storage tanks, landfill sites, transportation spills, municipal waste, industrial discharges, and pesticide use. Ethylbenzene is allowed for use as a formulant in pesticide preparations in Canada, but not an active ingredient.
Exposure estimates to ethylbenzene in consumer products were produced for Health Canada’s State of the Science Report. Exposure sources included acrylic enamel aerosol spray paint, latex wall paint, gasoline and cigarettes. In Ontario, ethylbenzene is typically 1.4% of regular unleaded gasoline and 1.7% of premium unleaded gasoline.
Estimates of daily intake for the general population were also calculated using values for indoor and outdoor air, drinking water, food and beverages and soil. Estimates ranged from 95 to 287 µg/kg-body weight per day depending on age.
Searches of environmental and consumer product databases yielded the following results on current potential for exposure to ethylbenzene in Canada:
NPRI and US Household Products Database
Search term: ‘ethylbenzene'
Released into Environment
Oil sands, refineries, and vehicle manufacture (233 facilities)
Sent to off-site recycling
t = tonne
US Household Products 2013
Hobby paints, home interior and exterior paints, decorative snow materials, and 4 insecticides
Our team has performed a detailed scan of exposure control resources and assembled a compilation of key publications and resources. These are organized by type of exposure (environmental or occupational) and by specificity (general or carcinogen-specific). Please visit our Exposures Reduction Resources page to view.
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. To learn more about policies specific to ethylbenzene on the Directory, click here. For questions about this resource, please contact Michelle Halligan, from the prevention team at the Canadian Partnership Against Cancer.