General Description
Colorless needles, gray flakes or off-white lumpy solid. Phenolic odor. Formerly used as a fungicide and bactericide.
Reactivity Profile
2,4,5-TRICHLOROPHENOL(95-95-4) is a weak monobasic acid. Incompatible with acid chlorides, acid anhydrides and oxidizing agents. Produces dioxin in alkaline medium at high temperatures
Air & Water Reactions
Insoluble in water.
Fire Hazard
Literature sources indicate that this chemical is nonflammable.
Chemical Properties
White to pale brown solid
Physical properties
Colorless crystals or yellow to gray flakes with a strong, disinfectant or phenolic odor. At 40 °C,
the average odor threshold concentration and the lowest concentration at which an odor were
detected were 350 and 63 μg/L, respectively. At 25 °C, the lowest concentration at which a taste
was detected was 100 μg/L (Young et al., 1996).
Uses
2,4,5-Trichlorophenol is used as a broad range pesticide against insects, fungi, vegetation and bacteria. It has become a common environmental contaminant and probable human carcinogen.
Definition
ChEBI: A trichlorophenol carrying chloro groups at positions 2, 4 and 5.
Preparation
2,4,5-Trichlorophenol is prepared indirectly, by the alkaline hydrolysis of 1,2,4,5-tetrachlorobenzene,because the direct chlorination of 2,5-dichlorophenol, difficult to achieve, proceeds with poor yield.
Hazard
May cause skin irritation.
Health Hazard
If your skin comes into contact with 2,4,5-trichlorophenol, it may burn the skin and produce redness and edema in humans. It also irritates the eyes, nose, pharynx, and lungs in humans.
Tests involving acute exposure of rats, mice, and guinea pigs have demonstrated 2,4,5-trichlorophenol to havemoderateacute toxicity by oral exposure.
Environmental Fate
Biological. Chloroperoxidase, a fungal enzyme isolated from Caldariomyces fumago,
chlorinated 2,4,5-trichlorophenol to give 2,3,4,6-tetrachlorophenol (Wannstedt et al., 1990).
Photolytic. When 2,4,5-trichlorophenol (100 μM) in an oxygenated, titanium dioxide (2 g/L)
suspension was irradiated by sunlight (λ ≥340 nm), complete mineralization to carbon dioxide and
water and chloride ions was observed (Barbeni et al., 1987a).
The following phototransformation half-lives were reported for 2,4,5-trichlorophenol in
estuarine water exposed to sunlight and microbes: 1 h during winter; in distilled water: 0.6 and 1 h
during summer and winter, respectively; in poisoned estuarine water: 14 and 24 h during summer
and winter, respectively (Hwang et al., 1986).
A photooxidation rate constant of <3,000/M·sec was reported for the reaction of 2,4,5-
trichlorophenol and ozone in water at a pH range of 1.2 to 1.5 (Hoigné and Bader, 1983).
Chemical/Physical. 2,4,5-Trichlorophenol will not hydrolyze because it does not contain a
hydrolyzable functional group (Kollig, 1993).
During the manufacture/synthesis of 2,4,5-T using alkalies at high temperatures, some TCDD
may form (Worthing and Hance, 1991).
Purification Methods
Crystallise the phenol from EtOH or pet ether. [Beilstein 6 IV 962.]
