Ethylbenzene is used primarily in the production of styrene and synthetic polymers. It is used as a solvent; a constituent of asphalt and naphtha; and in synthetic rubber, fuels, paints, inks, carpet glues, varnishes, tobacco products, and insecticides. It is a component of automotive and aviation fuels. It is also used to make other chemicals, including acetophenone, cellulose acetate, diethyl-benzene, ethyl anthraquinone, ethylbenzene sulfonic acids, propylene oxide, and alpha-methylbenzyl alcohol.
Substance name: Ethylbenzene
CASR number: 100-41-4
Molecular formula: C8H10
Synonyms: EB, ethylbenzol, phenylethane, Ethyl Benzene
Ethylbenzene is a colourless liquid that smells like petrol.
Boiling Point: 136.2°C
Melting Point: 94.97°C
Vapour Density: 3.66
Vapour Pressure: 9.53 mm Hg at 25°C
Specific Gravity: 0.867 at 20°C
Ethylbenzene is a flammable and combustible liquid. Its vapours are heavier than air and may travel to a source of ignition and flash back. In liquid form, it floats on water and may travel to a source of ignition and spread fire. I ts combustion may produce irritants and toxic gases. Ethylbenzene may accumulate static electricity and will react with oxidising materials. It is miscible with organic solvents and soluble in alcohol and ether. It evaporates at room temperature and burns easily. It moves easily into the air from water and soil and is most commonly found as a vapour in the air.
The National Pollutant Inventory (NPI) holds data for all sources of ethylbenzene emissions in Australia.
Exposure can irritate the eyes, nose and throat. High concentration can cause you to become dizzy, light headed, or to pass out. Very high levels can cause paralysis, trouble breathing and death. Prolonged exposure can cause drying, scaling and even blistering. High exposure may damage the liver. Chronic (long term) health effects can occur at some time after exposure to ethylbenzene and can last for months or years. Ethylbenzene in high levels is broken down more slowly in your body than low levels of ethylbenzene. Similarly, ethylbenzene mixed with other solvents is also broken down more slowly than ethylbenzene alone.
Entering the body
When you breathe air containing ethylbenzene vapour, it enters your body rapidly and almost completely through your lungs. Ethylbenzene in food or water can also rapidly and almost completely enter your body through the digestive tract. It may enter through your skin when you come into contact with liquids containing ethylbenzene. Ethylbenzene vapours do not enter through your skin to any large degree. People living in urban areas or in areas near hazardous waste sites may be exposed by breathing air or by drinking water contaminated with ethylbenzene.
In the work place exposure to ethylbenzene occurs in factories that use ethylbenzene to produce other chemicals as well as gas, petroleum and coal tar processes. Other occupational exposure may be associated with varnish workers, spray painters, and persons involved in gluing operations. Exposure to ethylbenzene occurs from the use of certain consumer products, gasoline, pesticides, solvents, carpet glues, varnishes, paints, and tobacco smoke.
Workplace exposure standards
Safe Work Australia sets the workplace exposure standard for ethylbenzene through the workplace exposure standards for airborne contaminants:
- Maximum eight hour time weighted average (TWA): 100 parts per million (434 mg/m3)
- Maximum short term exposure limit (STEL): 125 parts per million (543 mg/m3)
These standards are only appropriate for use in workplaces and are not limited to any specific industry or operation. Make sure you understand how to interpret the standards before you use them.
Drinking water guidelines
The Australian Drinking Water Guidelines include the following guidelines for acceptable water quality:
- Maximum of 0.3 milligrams per litre of water for health purposes
- Maximum of 0.003 milligrams per litre of water for aesthetic considerations
Acute toxic effects may include the death of animals, birds, or fish, and death or low growth rate in plants. Ethylbenzene has high acute toxicity to aquatic life. It has caused injury to various agricultural crops. Insufficient data are available to evaluate or predict the short-term effects of ethylbenzene to birds or land animals. Chronic toxic effects may include shortened lifespan, reproductive problems, lower fertility, and changes in appearance or behaviour. Ethylbenzene has a slight tendency to bioaccumulate.
Entering the environment
Ethylbenzene is very volatile so is mostly present in air. It can also be transported by water. It can also move very quickly into groundwater, since it does not readily bind to soil . About 99.5% of ethylbenzene will eventually end up in air; the rest will end up in the water.
Where it ends up
Once in the air, other chemicals help break down ethylbenzene into chemicals found in smog. This breakdown happens in about 3 days with the aid of sunlight. In surface water such as rivers and harbours, ethylbenzene breaks down by reacting with other compounds naturally present in the water. In soil, the major way ethylbenzene is broken down is by soil bacteria.
Point sources of ethylbenzene are factories that use ethylbenzene as part of their manufacturing process and from coal tar and petroleum processing facilities. Ethylbenzene is also emitted from some hazardous waste sites.
Diffuse sources, and industry sources included in diffuse emissions data
Ethylbenzene is emitted from a wide range of products and has been widely detected in low concentrations both indoors and outside. Indoor concentrations may be higher due to a greater number of sources. It is present in tobacco smoke.
It occurs naturally in coal tar and petroleum.
Ethylbenzene will be released from fuel filling and from vapours from motor vehicle fuel tanks.
Gasoline contains about 2% ethylbenzene by weight. Other products that may contain ethylbenzene include; household paints, agricultural chemicals, automotive paints and primers, car body polish and cleaners, bathroom tub and tile cleaners, building and construction plastic foam insulation, floor polish, furniture polish and cleaners, ground/traffic marking coatings, herbicides, insecticides, laundry starch preparations, loose mineral wool fibre, non-structural caulking compounds and sealants, cleaning and sanitation products, oven cleaners, paint and varnish removers, paint thinners, rug and upholstery cleaners, carpets and rugs, sheet vinyl flooring and waterproofing compounds.
Sources used in preparing this information
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- Australian and New Zealand Environment and Conservation Council (ANZECC) (1992), Australian Water Quality Guidelines for Fresh and Marine Waters.
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- New Jersey Dept of Health, Right to Know, TRIFacts (accessed, June 1999)
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- Safe Work Australia, Workplace exposure standards for airborne contaminants, accessed October 2018.
- National Health and Medical Research Council (NHMRC), Australian Drinking Water Guidelines (2011) - Updated October 2017, accessed May 2018