CAS number
- 108-70-3
Molecular formula
- C6H3Cl3
Formula weight
- 181.5 g/mol
Family
- Chlorobenzenes
Compound properties list|
| Melting/boiling point | 64 °C | Solid |
| Relative density | 0 g/cm3 | N/A |
| Vapour pressure | 0.6 mm Hg | Low volatility |
| Vapour density | 0 | N/A |
| Solubility in water | 6 mg/L | Low solubility |
| Henry's law constant | 3 x 10-3atm·m3/mol | Rapid volatilization when dissolved |
| log Koc (Depending on soil or sediment characteristics) | 2.6 - 5.7* | Strong adsorption to organic matter |
At 20 0C, 1,3,5-trichlorobenzene is a solid with low volatility and solubility. Once it is
dissolved, it rapidly volatilizes and adsorbs strongly to organic matter. When present in the soil,
it volatilizes and dissolves slowly. Once dissolved, 1,3,5-trichlorobenzene can reach the
groundwater table or drain into a waterway, where it will be diluted before volatilizing. Fragments
of 1,3,5-trichlorobenzene can also be carried into a waterway and deposited at the bottom, where
they will dissolve slowly. Once the source has been removed, 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.
1,3,5-trichlorobenzene should be handled with care, as it is toxic.
Although there are currently no producers of trichlorobenzenes in Canada, an estimated 40
to 50 tonnes per year were imported during the mid-1990s. Of this amount, about 30 tonnes were used
as solvents in textile manufacturing, and about 15 tonnes were used as intermediates in the
production of other chemicals.
In the past, trichlorobenzenes were used in combination with polychlorinated biphenyls (PCBs) in
dielectric fluids for transformers and capacitors until 1980 when regulations prohibited new uses of
PCB-containing dielectric fluids. Approximately 2,600,000 tonnes of trichlorobenzenes are present
in transformer dielectric fluids either in use or stored before disposal. In the United States,
trichlorobenzenes are also used as degreasing agents and lubricants.
Trichlorobenzene isomers have been identified in pulp and paper mill effluents. Effluents from
iron and steel manufacturing contribute to the environmental loading of trichlorobenzenes, while
petroleum refinery effluents have been reported to contain trichlorobenzene isomers. The more highly
chlorinated benzenes, particularly hexachlorobenzene, are subject to reductive dechlorination, which
may contribute to the accumulation of the lower chlorinated homologues (example, dichlorobenzenes and
trichlorobenzenes) in buried sediments.
