General Description
A white solid with a sharp chlorobenzene odor. Insoluble in water and denser than water. Hence sinks in water. Melting point 63-64°C (145-147°F).
Reactivity Profile
1,2,3-TRICHLOROBENZENE(87-61-6) can react with oxidizing agents. . May emit toxic hydrogen chloride and phosgene gases in fire.
Air & Water Reactions
Insoluble in water.
Health Hazard
Inhalation may cause irritation of respiratory tract. Irritating to the eyes. May redden skin on contact. Ingestion may cause liver damage.
Description
Trichlorobenzenes (TCBs) are synthetic chemicals that
occur in three different isomeric forms. The three chlorinated
cyclic aromatic isomers are 1,2,3-trichlorobenzene (1,2,3-TCB),
1,2,4-trichlorobenzene (1,2,4-TCB), and 1,3,5-trichlorobenzene
(1,3,5-TCB). 1,2,4-TCB is one of the 188 chemicals designated
as a hazardous air pollutant under the Clean Air Act.
Chemical Properties
White crystalline
Definition
ChEBI: 1,2,3-trichlorobenzene is a trichlorobenzene carrying chloro substituents at positions 1, 2 and 3.
Environmental Fate
Biological. Under aerobic conditions, soil microbes are capable of degrading 1,2,3-
trichlorobenzene to 1,2- and 1,3-dichlorobenzene and carbon dioxide (Kobayashi and Rittman,
1982). A mixed culture of soil bacteria or a Pseudomonas sp. transformed 1,2,3-trichlorobenzene
to 2,3,4-, 3,4,5-, and 2,3,6-trichlorophenol (Ballschiter and Scholz, 1980).
In an enrichment culture derived from a contaminated site in Bayou d’Inde, LA, 1,2,3-
trichlorobenzene underwent reductive dechlorination to 1,2- and 1,3-dichlorobenzene at relative
molar yields of 1 and 99%, respectively. The maximum dechlorination rate, based on the
recommended Michaelis-Menten model, was 60 nM/d (Pavlostathis and Prytula, 2000).
Photolytic. The sunlight irradiation of 1,2,3-trichlorobenzene (20 g) in a 100-mL borosilicate
glass-stoppered Erlenmeyer flask for 56 d yielded 32 ppm pentachlorobiphenyl (Uyeta et al.,
1976).
Chemical/Physical. At 70.0 °C and pH values of 3.07, 7.13, and 9.80, the hydrolysis half-lives
were calculated to be 19.2, 15.0, and 34.4 d, respectively (Ellington et al., 1986).
Emits toxic chloride fumes when heated to decomposition.
Purification Methods
Crystallise it from EtOH. [Beilstein 5 IV 664.]
Toxicity evaluation
The liver is themain target of trichlorobenzenes irrespective of
the route of exposure. The mechanisms of liver toxicity
induced by these chemicals have not been illustrated. It might
involve intermediate arene oxides formed during initial
transformation to trichlorophenols. In addition, exposure
to 1,2,4-TCB induced porphyria in rats by inducing δ-aminolevulinic
acid (ALA) synthetase, a rate-limiting enzyme
in the biosynthesis of heme, and also heme oxygenase, a ratelimiting
enzyme in the degradation of heme synthetase, and
therefore increasing heme production.
