CAS number
- 108-90-7
Molecular formula
- C6H5Cl2
Formula weight
- 112.6 g/mol
Family
- Chlorobenzenes
Compound properties list|
| Melting/boiling point | -45 °C / 132 °C | Liquid |
| Relative density | 1.1 g/cm3 | Sinks in water |
| Vapour pressure | 11 mm Hg | Moderately volatile |
| Vapour density | 3.9 | Much denser than air |
| Solubility in water | 450 mg/L | Low solubility |
| Henry's law constant | 3 x 10-3atm·m3/mol | Rapid volatilization once dissolved |
| log Koc (Depending on soil or sediment characteristics) | 1.9 - 2.6* | Moderate adsorption to organic matter |
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.
Chlorobenzene should be handled with care as it is flammable and toxic.
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.
