Fact sheet: Toluene

From: Public Services and Procurement Canada

Discover a list of a contaminant's important chemical properties, how it will react in the environment, main sources of contamination related, and a brief overview of health and safety issues.

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General information

CAS number


Molecular formula


Formula weight

92.1 g/mol


Monocyclic aromatic hdrocarbons (MAH)

Properties (at room temperature where applicable)

Compound properties list
Melting/boiling point -95 °C / 110 °CLiquid
Relative density0.87 g/cm3Floats on water
Vapour pressure25 mm HgModerately volatile
Vapour density3.2Denser than air
Solubility in water525 mg/LLow solubility
Henry's law constant6 x 10-3 atm·m3/molRapid volatilization when dissolved
log Koc (Depending on soil or sediment characteristics)1.7 - 3.0*Moderate adsorption to organic matter

Environmental behaviour

At 20 0C, toluene is a liquid that floats on water and is low to moderately volatile. Characterized by its low solubility, it will volatilize rapidly once dissolved and adsorbs moderately to organic matter. During a spill, this compound will evaporate in part but the majority of the product will enter into the soil or migrate into a waterway. Liquid toluene can accumulate along the capillary fringe (groundwater) or form a film on the water's surface which will promote its solubilization and volatilization. The adsorbed toluene in the vadose and saturated zones will take some time to disappear, liberating contamination in either the gaseous (primarily) or dissolved state. The resulting dissolved plume will be generally limited in size while the gaseous plume will be relatively large in size.

Health and safety

Toluene should be handled with care as it is flammable and toxic.

Principal resources

Toluene is an aromatic hydrocarbon naturally present in crude petroleum and in the tolu tree. It is produced during the refining of crude oil, in making coke from coal, and as a by-product of styrene manufacturing. Toluene is added to gasoline along with benzene and xylene. The largest releases of toluene occur during the production, transportation and use of gasoline, which contains about 5 to 7 % toluene by weight (more than 10 % in premium unleaded).

Toluene is also a good solvent and thus used in making paints, paint thinners, fingernail polish, lacquers, adhesives, and rubber, as well as in some printing and leather tanning processes. Significant quantities of toluene are released in association with the production, use and disposal of industrial and consumer products that contain toluene.


Agency for Toxic Substances and Disease Registry (ATSDR). 2000. Toxicological Profile for Toluene. U.S. Department of Health and Human Services, Public Health Service, Georgia, USA. (Viewed December 2013)

Canadian Council of Ministers of the Environment. 1999. Canadian Water Quality Guidelines for the Protection of Aquatic Life: Toluene. In: Canadian Environmental Quality Guidelines. Canadian Council of Ministers of the Environment, Manitoba, Canada. (Viewed March 2010)

Montgomery, John H. 2007. Groundwater Chemicals, Desk Reference, Fourth Edition, CRC Press, Taylor and Francis Group, Florida, USA.