Fact sheet: Chlorobenzene

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

112.6 g/mol



Properties (at room temperature where applicable)

Compound properties list
Melting/boiling point -45 °C / 132 °CLiquid
Relative density1.1 g/cm3Sinks in water
Vapour pressure11 mm HgModerately volatile
Vapour density3.9Much denser than air
Solubility in water450 mg/LLow solubility
Henry's law constant3 x 10-3atm·m3/molRapid volatilization once dissolved
log Koc (Depending on soil or sediment characteristics)1.9 - 2.6*Moderate adsorption to organic matter

Environmental behaviour

At 20 0C, chlorobenzene is a liquid denser than water and moderately volatile. Characterized by low solubility, it will volatilize rapidly once dissolved and adsorbs moderately to organic matter. During a spill, this compound will partially evaporate but may also enter into the soil or drain into a waterway. Once it encounters water (surface or subsurface), chlorobenzene will dissolve or sink (primarily) until it reaches an impermeable surface. The liquid chlorobenzene that accumulates in a saturated zone will slowly dissolve before volatilizing. The adsorbed chlorobenzene in the vadose and saturated zones will take a long time to disappear, liberating contamination in either the gaseous or dissolved state. The resulting plumes (gaseous or dissolved) will be relatively small in size.

Health and safety

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

Principal resources

Chlorobenzene does not occur widely in nature, but is manufactured for use as a solvent and in the production of other chemicals. Production of chlorobenzene in the United States has declined by nearly 60%, from 1960 to 1987. This decline was attributed primarily to the replacement of chlorobenzene by cumene in phenol production and the cessation of DDT production in the United States. In addition, pesticide production using chlorobenzene as an intermediate has declined.

Chlorobenzene is produced commercially by the chlorination of benzene in the presence of a catalyst (example, ferric chloride, aluminum chloride or stannic chloride). This process yields a mixture of chlorobenzene, dichlorobenzenes, and more chlorinated analogs.

The current primary uses of chlorobenzene are as a solvent for pesticide formulations, manufacturing of diisocyanate, degreasing automobile parts, and for the production of nitrochlorobenzene. Chlorobenzene is also used in silicone resin production, as a solvent for paints, as insecticide, pesticide and intermediate in dyestuffs production and as an intermediate in the synthesis of other halogenated organics.


Agency for Toxic Substances and Disease Registry (ATSDR). 1990. Toxicological profile for chlorobenzenes. U.S. Department of Health and Human Services, Public Health Service. Atlanta, Georgia, U.S.A. (Viewed December 2013)

Canadian Council of Ministers of the Environment. 1999. Canadian water quality guidelines for the protection of aquatic life: Chlorinated benzenes-1,4-Dichlorobenzene. In: Canadian environmental quality guidelines, 1999. Canadian Council of Ministers of the Environment, Winnipeg. Canada. (Viewed December 2013)

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