State of the Science Report for Ethylbenzene

Identity, Uses and Sources of Exposure

Ethylbenzene is used in a variety of industrial processes and in the manufacture of many industrial and consumer products. Therefore, there are many potential sources of exposure for the Canadian population.

Ethylbenzene is a volatile organic compound and occurs naturally in petroleum and crude oil (ATSDR, 1999; NLM, 2003). It is produced by various processes from acetophenone, benzene, chlorobenzene, ethylenebenzene, naphthenes and xylene (NLM, 2003). Ethylbenzene can also be extracted from coal and may result from biomass combustion (ATSDR, 1999; NLM, 2003). A survey conducted pursuant to Section 71 of CEPA 1999 indicated that during the year 2000, 1690 kilotonnes of ethylbenzene at a concentration higher than 1% were manufactured in Canada and 18 kilotonnes of ethylbenzene at a concentration higher than 1% were imported into Canada. In addition, several companies reported either importing or manufacturing ethylbenzene at a concentration lower than 1% and in a quantity meeting the reporting threshold of 10 000 kg (Environment Canada, 2001). The survey also reported the use of ethylbenzene as a feedstock for petrochemicals and other organic chemicals, as a solvent in paints and coatings and in other solvent applications (Environment Canada, 2001). Reported uses in other jurisdictions fall into the categories of manufacture, solvents, fuels and coatings (ATSDR, 1999; NLM, 2003). The use of ethylbenzene in insecticides and carpet glues has also been reported (ATSDR, 1999).

Ethylbenzene is released from facilities that manufacture the substance or use it as a solvent or as an intermediate in the production of other chemicals. In 2001, facilities from across Canada reported to the National Pollutant Release Inventory on-site environmental releases totalling approximately 800 tonnes, transfers for disposal totalling 86 tonnes and transfers for recycling totalling 630 tonnes (Environment Canada, 2003). As a component of benzene, toluene, ethylbenzene and xylene (BTEX) emissions, ethylbenzene is also released from glycol dehydrators used to remove water from natural gas. According to the survey conducted pursuant to Section 71 of CEPA 1999, ethylbenzene is used mostly in destructive processes or in non-dispersive uses where release into the environment is unlikely. However, ethylbenzene is also reported for use in consumer products such as paints, solvents and gasoline, from which it may be released. It is also present in adhesives and tobacco smoke (Daisey et al., 1994; ATSDR, 1999). Ethylbenzene has been detected in ambient air, indoor air, drinking water, soil and food; however, the primary route of exposure is expected to be inhalation.