2,4,5-TRICHLOROPHENOL

CASRN: 95-95-4; DOT: 2020; molecular formula: C6H3Cl3O; FW: 197.45; RTECS: SN1400000; Merck Index: 12, 9772 Physical state, color, and odor: 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). Melting point (°C): 68.5 (Plato, 1972) Boiling point (°C): 252 (Weast, 1986) Density (g/cm3): 1.5 at 75 °C (quoted, Verschueren, 1983) 1.678 at 25 °C (Sax, 1984) Dissociation constant, pKa: 6.90 (Hoigné and Bader, 1983) 7.00 (Blackman et al., 1955) 7.37 at 25 °C (Dean, 1973) Diffusivity in water (x 10-5 cm2/sec): 0.62 at 20 °C using method of Hayduk and Laudie (1974) Flash point (°C): Nonflammable (Weiss, 1986) Lower explosive limit (%): Nonflammable (Weiss, 1986) Upper explosive limit (%): Nonflammable (Weiss, 1986) Heat of fusion (kcal/mol): 5.7 (DSC, Plato, 1972) Henry’s law constant (x 10-7 atm⋅m3/mol): 1.76 at 25 °C (estimated, Leuenberger et al., 1985a)

3.27 (fathead minnows, Call et al., 1980) Soil organic carbon/water partition coefficient, log Koc: 2.56 (Brookstone clay loam, Boyd, 1982) 2.45 (river sediment, Eder and Weber, 1980) 2.55 (loamy sand, Kjeldsen et al., 1990) 3.30 (sandy soil), 3.34 (sand), 3.38 (peaty sand) (Van Gestel, 1993) Octanol/water partition coefficient, log Kow: 3.72 (quoted, Leo et al., 1971) 4.10 (Xie et al., 1984) 4.19 (Schellenberg et al., 1984) 3.80 (Saarikoski and Viluksela, 1982) 3.85 (Schultz et al., 1989) 4.02 (Kishino and Kobayashi, 1994) Solubility in organics: Soluble in ethanol and ligroin (U.S. EPA, 1985) Solubility in water: 1,190 mg/kg at 25 °C (quoted, Verschueren, 1983) 948 mg/L at pH 5.1 (Blackman et al., 1955) 1.2 g/L at 25 °C (quoted, Leuenberger et al., 1985a) 649 mg/L at 25 °C and pH 4.9 (Ma et al., 1993) Vapor pressure (x 10-3 mmHg): 3.5 at 8 °C, 22 at 25 °C (quoted, Leuenberger et al., 1985a) 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 2,4,5trichlorophenol 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). Toxicity: EC50 (48-h) for marine polychaete Platynereis dumerilii 2.55 mg/L (Palau-Casellas and Hutchinson, 1998). LC50 750 to 1,106 µg/L (soil porewater concentration) for earthworm (Eisenia andrei) and 4.1 and 6.9 mg/L (soil porewater concentration) for earthworm (Lumbricus rubellus) (Van Gestel and

LC50 (96-h) for bluegill sunfish 450 µg/L (Spehar et al., 1982), Cyprinodon variegatus 1.7 ppm using natural seawater (Heitmuller et al., 1981). LC50 (72-h) for Cyprinodon variegatus 1.7 ppm (Heitmuller et al., 1981). LC50 (48-h) for red killifish 12 mg/L (Yoshioka et al., 1986), Daphnia magna 2.7 mg/L (LeBlanc, 1980), marine polychaete Platynereis dumerilii 4.24 mg/L (Palau-Casellas and Hutchinson, 1998), Cyprinodon variegatus 1.7 ppm (Heitmuller et al., 1981). LC50 (24-h) for Daphnia magna 3.8 mg/L (LeBlanc, 1980), Protozoan (Spirostomum teres) 2.00 mg/L (Twagilimana et al., 1998), Cyprinodon variegatus 2.4 ppm (Heitmuller et al., 1981). LC50 (30-min) for Protozoan (Spirostomum teres) 12.72 mg/L (Twagilimana et al., 1998). Acute oral LD50 for guinea pigs 1,000 mg/kg, mice 600 mg/kg, rats 820 mg/kg (quoted, RTECS, 1985). Heitmuller et al. (1981) reported a NOEC of 1.0 ppm. Uses: Fungicide; bactericide; organic synthesis.