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 Hazardous Substances Data Bank (HSDB) for other synonyms and more information.
Ethylbenzene has been classified by the International Agency for Research on Cancer (IARC) as Group 2B, possibly carcinogenic to humans. Available epidemiological studies did not provide adequate evidence of carcinogenicity in humans, however animal studies showed 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 irritate eyes and throat. Chronic exposure may also cause haematological effects and damage to the inner ear.
Drinking water standards: 2.4 μg/L < br>
Sets vapour standards for:
Agricultural, urban park, residential settings: 1000 μg/m3
Commercial settings: 3000 μg/m3
Industrial settings: 9000 μg/m3
(Vapours derived from soil, sediment, or water)
mg/L = milligrams per litre
µg/m3 = micrograms per cubic meter
µg/g = micrograms per gram
µg/L = micrograms per litre
* for limiting the effect of odour
Ethylbenzene was not included in other Canadian government environmental guidelines reviewed.[10,11,12,13,14]
DSL – high priority substance with greatest potential for exposure
National Classification System for Contaminated Sites
Rank = "Medium hazard"
Agreement Respecting the Great Lakes Basin Ecosystem
Listed as a "Hazardous Polluting Substance
* Under the Canadian Environmental Protection Act (CEPA) 1999, ethylbenzene was chosen for screening to investigate its potential to enter the environment in harmful amounts. This screening assessment includes updated information: ecological sections include recent literature searches up to December 2009 and the human health sections include information up to January 2013. The final screening assessment, published in April 2016, concluded that ethylbenzene does not constitute a danger to human health or life.
DSL = domestic substance list
Ethylbenzene was not included in other Canadian government chemical listings reviewed.[20,21]
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.[4,5,22] It is also used as a solvent and reagent for making various other chemicals. It is 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.
Production and Trade
239 t of 'ethylbenzene'
526 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. The largest exposed occupational groups are 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 production and handling of ethylbenzene or while using mixed xylenes, which are used as solvents for paints, inks, lacquers, and in rubber and plastic production. Exposure can also occur in coal and petroleum refining and in 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 were reported in the 1990s as a by-product of styrene production.
According to Health Canada, the primary route of ethylbenzene exposure is inhalation. CAREX Canada estimates that ethylbenzene levels in indoor air result in an increased risk of cancer (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) do not result in increased risks of cancer.
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 is mobile enough to cause concern as a potential groundwater contaminant. Sources of soil and groundwater contamination include leaking underground gasoline storage tanks, landfill sites, transportation spills, municipal waste, industrial discharges, and pesticide use.[19,22] Ethylbenzene is allowed to be used as a formulant in pesticide preparations in Canada.[19,26]
Ethylbenzene has been detected in numerous consumer products including 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 9.83 to 28.7 µg/kg-body weight per day depending on age.
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 ethylbenzene in Canada:
NPRI and US Household Products Database
Substance name: 'Ethylbenzene'
Released into Environment
Oil sands, vehicle manufacture, petroleum and coal product manufacturing, metal manufacturing (224 facilities)
Sent to off-site recycling
t = tonne
US Household Products 2016
Hobby paints, home interior and exterior paints, decorative snow materials, and five 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. Click here to learn more about policies specific to ethylbenzene in the Directory. For questions about this resource, please contact a member of the Prevention Team at the Canadian Partnership Against Cancer at firstname.lastname@example.org.