Environmental Sources

Toluene is manufactured for use in other products, is a by-product of industrial processes and occurs naturally in the environment. Toluene is a clear, colourless liquid with a distinctive smell. Toluene occurs naturally in crude oil and in the tolu tree. It is also produced in the process of making petrol and other fuels from crude oil and making coke from coal. Because Toluene is a volatile organic compound, it evaporates easily and exposure can be via inhalation.

Toluene is used in making paints, paint thinners, fingernail polish, lacquers, adhesives, and rubber and in some printing and leather tanning processes. Toluene enters the environment when you use materials that contain it. It can also enter surface water and groundwater from spills of solvents and petroleum products as well as from leaking underground storage tanks at petrol stations and other facilities. When toluene-containing products are placed in landfills or waste disposal sites, the toluene can enter the soil or water near the waste site.

Human Health effects

Toluene may affect the nervous system. Low to moderate levels can cause tiredness, confusion, weakness, drunken-type actions, memory loss, and nausea, loss of appetite, and hearing and colour vision loss. These symptoms usually disappear when exposure is stopped.

Inhaling high levels of toluene in a short time can make you feel light-headed, dizzy, or sleepy. It can also cause unconsciousness, and even death. High levels of toluene may affect your kidneys.

Exposure limits

- The Bay Area Air Quality Management District in San Francisco, USA documented a background concentration level of 2.0 ppb for toluene for the whole bay area in San Francisco.

- US EPA has set a limit of 1 milligram per litre of drinking water (1 mg/L).

- Discharges, releases, or spills of more than 1,000 pounds of toluene must be reported to the National Response Centre.

- The US Occupational Safety and Health Administration has set a limit of 200 parts toluene per million of workplace air (200 ppm) TWA, 500 mg/m³ STEL and a ceiling value of 300 ppm.

- The ACGIH (American Conference of Government Industrial Hygienist) has TWA for skin contact with Toluene of 50 ppm.

- The US NIOSH (National Institute for Occupational Safety and Health) has a toluene limit of 2000 ppm.

Sources and links:

www.atsdr.cdc.gov/tfacts53.html

www.modcon.co.il/exposure.htm

www.epa.gov/ttn/uatw/hapindex.html

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