CAS number
- 106-46-7
Molecular formula
- C6H4Cl2
Formula weight
- 147 g/mol
Family
- Chlorobenzenes
Compound properties list|
| Melting/boiling point | 25 °C | Solid |
| Relative density | 1.24 g/cm3 | Sinks in water |
| Vapour pressure | 1 mm Hg | Low to moderate volatility |
| Vapour density | 5.1 | Much denser than air |
| Solubility in water | 70 mg/L | Low solubility |
| Henry's law constant | 2 x 10-3atm·m3/mol | Rapid volatilization once dissolved |
| log Koc (Depending on soil or sediment characteristics) | 2.5 - 3.3* | Strong adsorption to organic matter |
At 20 0C, 1,4-dichlorobenzene is a solid with low to moderate volatility and low
solubility. Once it is dissolved, it volatilizes rapidly and adsorbs strongly to organic matter.
When present in the soil, it volatilizes and dissolves slowly. Once dissolved, 1,4-dichlorobenzene
can reach the water table or drain into a waterway where it will be diluted before volatilizing.
Fragments of 1,4-dichlorobenzene can also be carried into waterways where they will be deposited at
the bottom and slowly dissolve. Once the source is gone, the adsorbed phase will take a long time to
disappear, liberating contamination in either the gaseous or dissolved state. The resulting plumes
(gaseous and dissolved) are generally small in size.
1,4-dichlorobenzene should be handled with care as it is flammable and toxic.
1,4-dichlorobenzene does not occur naturally. Chlorinated benzenes are typically produced
by reacting liquid benzene with gaseous chlorine in the presence of a catalyst at moderate
temperatures and atmospheric pressures. This reaction yields a mixture of chlorobenzene isomers with
varying degrees of chlorination. 1,4-dichlorobenzene is the most important of the three
dichlorobenzene isomers.
1,4-dichlorobenzene is used industrially as a disinfectant, a deodorizer and air freshener, an
insect and bird repellent, and in the synthesis of polyethylene sulphide resin. Domestic uses are
primarily as a moth repellent (moth balls), as an air freshener, and as a toilet block.
1,4-dichlorobenzene is also used as an intermediate in the production of other chemicals such as
1,2,4-trichlorobenzene. Minor uses of 1,4- dichlorobenzene include the control of certain
tree-boring insects and ants, and in the control of blue mold in tobacco seed beds.
There is also evidence of dichlorobenzene production from the dehalogenation of more highly
chlorinated benzenes and during incineration of organic matter containing chlorine.
Agency for Toxic Substances and Disease Registry (ATSDR). 2006. Toxicological profile
for dichlorobenzenes. U.S. Department of Health and Human Services, Public Health Service.
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)
Environment Canada. 2009. CEPA Environmental Registry: Toxic Substances List-Updated
Schedule 1 as of December 27, 2006. Environment
Canada. (Viewed December 2013)
Environment Canada. 2003. Follow-up report on five PSL1 substances for which there was
insufficient information to conclude whether the substances constitute a danger to the
environment. Government of Canada. (Viewed December 2013)
Montgomery, John H. 2007. Groundwater Chemicals, Desk Reference, Fourth Edition, CRC
Press, Taylor and Francis Group, Florida, U.S.A.
