Ethylbenzene Profile

INDUSTRIAL CHEMICALS  POSSIBLE CARCINOGEN (IARC 2B)

CAS No. 100-41-4
IARC Monograph Vol. 77, 2000 (Group 2B)

Ethylbenzene Profile

General Information

Ethylbenzene is a volatile organic compound (VOC) in the ‘BTEX’ substance group which includes benzene, toluene, ethylbenzene, and xylene.[1] Ethylbenzene is a colourless liquid that smells similar to gasoline.[1] It exists naturally in petroleum, and is also an industrial chemical with a variety of uses.[2] Ethylbenzene may be referred to as phenylethane or EB.[2] See the Hazardous Substances Data Bank (HSDB) for other synonyms and more information.[2]

Ethylbenzene has been classified by the International Agency for Research on Cancer (IARC) as Group 2B, possibly carcinogenic to humans.[3] 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.[3]

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.[4]

Regulations and Guidelines

Occupational Exposure Limits (OEL) [5,6,7,8,9,10,11,12,13,14,15,16,17,18,19]

Canadian Jurisdictions OEL (ppm)
Canada Labour Code 20
AB, NB, NT, NU, QC, SK, YT 100
125 [stel]
BC, MB,NL, NS, ON, PE 20
Other Jurisdiction OEL (ppm)
ACGIH 2018 TLV 20
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

Jurisdiction Limit Year
Canadian Drinking Water Guidelines <0.0024 mg/L 2017[20]
Ontario Drinking Water Standards <0.0024 mg/L 2017[21]
Ontario Ambient Air Quality Criteria 24 hour: 1000 µg/m3 2016[22]
  *10 minute: 1900 µg/m3 2012[22]
Alberta Ambient Air Quality Objectives and Guidelines 1 hr: 2,000 μg/m3 2017[23]
BC’s Contaminated Sites Regulation, BC Reg 375/96 Sets soil standards for:
Agricultural and low density residential soil: 4000 μg/g
Urban park and high density residential soil: 8500 μg/g
Commercial soil: 25 000 μg/g
Industrial soil: 700 000 μg/g

 

Drinking water standards: 140 μg/L

Sets vapour standards for the protection of human health:
Agricultural, urban park, residential use standard: 1,000 μg/m3
Commercial use standard: 3,000 μg/m3
Industrial use standard: 9,000 μg/m3
Parkade use standard: 8,000 μg/m3
(Vapours derived from soil, sediment, or water)

2017[24]
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.[25,26,27,28]

Canadian Agencies/Organizations

Agency Designation/Position Year
Health Canada* DSL – high priority substance with greatest potential for exposure 2006[29]
National Classification System for Contaminated Sites Rank = “Medium hazard” 2008[30]
Agreement Respecting the Great Lakes Basin Ecosystem Listed as a “Hazardous Polluting Substance 1987[31]
* 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.[32] The final screening assessment, published in April 2016, concluded that ethylbenzene does not constitute a danger to human health or life.[33]
DSL = domestic substance list

Ethylbenzene was not included in other Canadian government chemical listings reviewed.[34,35]

Main Uses

Pure ethylbenzene is used almost exclusively as a precursor for styrene production.[3]

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.[3,4,36] It is also used as a solvent and reagent for making various other chemicals. It is found in asphalt and naphtha, tobacco products,[3] and gasoline (at up to 15%).[3]

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.[37]

Production and Trade

Activity Quantity Year
Export 239 t of ‘ethylbenzene’ 2015[38]
Import 526 t of ‘ethylbenzene’ 2015[38]
t = tonne

Environmental Exposures Overview

According to Health Canada, the primary route of ethylbenzene exposure is inhalation.[32] 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.[32] 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.[36] Tobacco and wood smoke also contain ethylbenzene.[36]

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.[18] Sources of soil and groundwater contamination include leaking underground gasoline storage tanks, landfill sites, transportation spills, municipal waste, industrial discharges, and pesticide use.[33,36] Ethylbenzene is allowed to be used as a formulant in pesticide preparations in Canada.[33,39]

Ethylbenzene has been detected in numerous consumer products including acrylic enamel aerosol spray paint, latex wall paint, gasoline, and cigarettes.[32] In Ontario, ethylbenzene is typically 1.4% of regular unleaded gasoline and 1.7% of premium unleaded gasoline.[32]

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.[32]

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

NPRI 2015[40]
Substance name: ‘Ethylbenzene’
Category Quantity Industry
Released into Environment 378 t Oil sands, vehicle manufacture,
petroleum and coal product manufacturing,
metal manufacturing (224 facilities)
Disposed of 223 t
Sent to off-site recycling 1,956 t
t = tonne
US Household Products 2016[41]
Search Term Quantity Product Type
‘Ethylbenzene’ >449 Hobby paints, home interior and exterior paints,
decorative snow materials, and five insecticides

For more information, see the environmental exposure estimate for ethylbenzene.

Occupational Exposures Overview

Inhalation is the most important route of occupational exposure.[4]

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.[3] Exposure can also occur in coal and petroleum refining and in production and handling of gasoline and bitumens.[4]

Although ethylbenzene is used in styrene production, exposure is expected to be low since the process is typically enclosed.[42] Low levels of ethylbenzene were reported in the 1990s as a by-product of styrene production.[4]

For more information, see the occupational exposure estimate for ethylbenzene.

Sources

1. Agency for Toxic Substances and Disease Registry (ATSDR). ToxFAQ Sheet: Ethylbenzene (2007) (PDF)
2. US National Library of Medicine. Hazardous Substances Data Bank (HSDB) (Search term: ‘Ethylbenzene’)
3. International Agency on Research for Cancer (IARC). Monograph summary, Volume 77 (2000) (PDF)
4. Agency for Toxic Substances and Disease Registry (ATSDR). Draft Toxicological Profile for ethylbenzene (2007) (PDF)
10. Government of Newfoundland and Labrador. Regulation 5,12 Occupational Health and Safety Regulations (2012)
11. Government of the Northwest Territories. Occupational Health and Safety Regulations, R-039-2015 (2016) (PDF)
13. The Canadian Legal Information Institute (CanLII). Government of Nunavut’s Occupational Health and Safety Regulations, Nu Reg 003-2016 (2010)
15. Government of Prince Edward Island. Occupational Health and Safety Act Regulations Chapter 0-1 (2013) (PDF)
17. Government of Saskatchewan. The Occupational Health and Safety Regulations, 1996 (2016) (PDF)
18. The Canadian Legal Information Institute (CanLII). Yukon’s Occupational Health Regulations, O.I.C. 1986/164 (2012) (PDF)
19. Occupational Safety and Health Administration (OSHA). Annotated PELs (2018)
21. The Canadian Legal Information Institute (CanLII). Ontario Drinking Water Quality Standards, O Reg 169/03 (2017)
22. Ontario Ministry of the Environment and Climate Change. Ontario’s Ambient Air Quality Criteria (2016)
23. Alberta Environment and Parks. Ambient Air Quality Objectives (2017)
24. Government of British Columbia. Contaminated Sites Regulation B.C. Reg. 375/96 (2017)
26. Health Canada. Cosmetic Ingredient Hotlist (2014)
28. The Canadian Legal Information Institute (CanLII). Regulation respecting the quality of drinking water, CQLR c Q-2, r 40 (2014)
30. Canadian Council of Ministers of the Environment (CCME). National Classification System for Contaminated Sites (2008) (PDF)
31. International Joint Commission. Revised Great Lakes Water Quality Agreement of 1978 (1978) (PDF)
33. Health Canada. Ethylbenzene (2016)
34. Environment and Climate Change Canada. CEPA List of Toxic Substances (1999)
36. Health Canada. Ethylbenzene and Health (2007) (PDF)
37. Camford Information Services. CPI Product Profiles: Ethylbenzene (2004)
38. International Trade Centre. TradeMap (Free subscription required)
40. Environment and Climate Change Canada. National Pollutant Release Inventory (NPRI) Facility Search (Substance name: ‘Ethylbenzene’)
41. US Household Products Database (HPD). Household Products (Search term: ‘Ethylbenzene’)
42. Organisation for Economic Co-Operation and Development Screening Information Data Sets (OECD SIDS). Report on Ethylbenzene (2002) (PDF)

Other Resources

  1. BC Ministry of the Environment. Environment Protection Division: Ambient air quality guidelines for Ethylbenzene; overview report (1981)
  2. World Health Organization (WHO). Ethylbenzene in Drinking Water (1996) (PDF)
  3. Agency for Toxic Substances and Disease Registry (ATSDR). ToxGuide for Ethylbenzene (2007) (PDF)

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