1,2,4-TRICHLOROBENZENE

Cl CASRN: 120-82-1; DOT: 2321; molecular formula: C6H3Cl3; FW: 181.45; RTECS: DC2100000; Merck Index: 12, 9760 Physical state, color, and odor: Colorless liquid with an odor similar to o-dichlorobenzene. Odor threshold concentration is 1.4 (quoted, Amoore and Hautala, 1983). Melting point (°C): 17 (Weast, 1986) Boiling point (°C): 213.492 (Růžička et al., 1998) Density (g/cm3): 1.4542 at 20 °C (Weast, 1986) 1.4460 at 25 °C (quoted, Standen, 1964) Diffusivity in water (x 10-5 cm2/sec): 0.78 at 20 °C using method of Hayduk and Laudie (1974) Flash point (°C): 105 (NFPA, 1984) Lower explosive limit (%): 2.5 at 150 °C (NFPA, 1984) Upper explosive limit (%): 6.6 at 150 °C (NFPA, 1984) Entropy of fusion (cal/mol⋅K): 12.8 (Tsonopoulos and Prausnitz, 1971) Heat of fusion (kcal/mol): 3.70 (Tsonopoulos and Prausnitz, 1971) Henry’s law constant (x 10-3 atm⋅m3/mol): 1.2 (gas stripping-GC, Oliver, 1985) 1.42 at 25 °C (gas stripping-UV spectrophotometry, Warner et al., 1987) 1.29, 1.05, 1.83, 19.2, and 29.7 at 10, 15, 20, 25, and 30 °C, respectively (EPICS, Ashworth et al.,

1988) 0.997 at 20.0 °C (wetted-wall column, ten Hulscher et al., 1992)

Dewulf et al., 1999)

Ionization potential (eV): 9.04 (Lias et al., 1998) Bioconcentration factor, log BCF: 3.36-3.57 (fish tank), 3.08 (Lake Ontario) (rainbow trout, Oliver and Niimi, 1985) 2.40 (algae, Geyer et al., 1984) 2.23 (Crassostrea virginica, Schimmel and Garnas, 1981) 3.15 (activated sludge), 2.69 (golden ide) (Freitag et al., 1985) 4.76 (Atlantic croakers), 4.90 (blue crabs), 3.54 (spotted sea trout), 4.68 (blue catfish) (Pereira et

al., 1988) 3.45 (fathead minnow), 3.37 (green sunfish), 2.95 (rainbow trout) (Veith et al., 1979) 3.11 (rainbow trout, Oliver and Niimi, 1985) 2.61 (fathead minnow, Carlson and Kosian, 1987) In fingerling rainbow trout (Salmo gairdneri), values of 1.71, 2.01, and 2.38 were reported for

muscle, liver, and bile, respectively, after an 8-h exposure; after a 35-d exposure, values of 1.95, 2.59, and 3.15 were reported for muscle, liver, and bile, respectively (Melancon and Lech, 1980)

Soil organic carbon/water partition coefficient, log Koc: 2.94 (Woodburn silt loam soil, Chiou et al., 1983) 3.01 (Scheunert et al., 1994) 3.14 (Wilson et al., 1981) 3.16 (peaty soil, Friesel et al., 1984) 3.98, 4.61 (lacustrine sediments, Chin et al., 1988) 3.09, 3.16 (Banerjee et al., 1985) 3.19, 3.27 (Marlette soil, Lee et al., 1989) 3.32 (Apison soil), 3.11 (Fullerton soil), 2.95 (Dormont soil) (Southworth and Keller, 1986) 3.49 (Charles River sediment, Wu and Gschwend, 1986) 4.08, 4.41, 5.11 (Paya-Perez et al., 1991) 2.73 (muck), 2.89 (Eustis sand) (Brusseau et al., 1990) Average Kd values for sorption of 1,2,4-trichlorobenzene to corundum (α-Al2O3) and hematite (α-

Fe2O3) were 0.0110 and 0.0232 mL/g, respectively (Mader et al., 1997) 3.58 (Calvert silt loam, Xia and Ball, 1999) Octanol/water partition coefficient, log Kow: 4.02 (Chiou, 1985; shake flask-GC, Pereira et al., 1988) 3.98 (generator column-GC, Miller et al., 1984; Chin et al., 1986; generator column, Doucette and

Andren, 1988) 4.23 (Mackay, 1982) 3.97 at 25 °C (shake flask-GC, Watarai et al., 1982) 4.11 (Hawker and Connell, 1988) 3.93 at 22 °C (shake flask-GC, Könemann et al., 1979) 4.176 (Kenaga and Goring, 1980) 4.12 (Anliker and Moser, 1987) 4.07 (estimated using HPLC, DeKock and Lord, 1987) 4.05 at 25 °C (shake flask-GLC, de Bruijn et al., 1989) 3.96 (estimated from HPLC capacity factors, Hammers et al., 1982) 3.63 (generator column-HPLC/GC, Wasik et al., 1981) 4.21 (estimated from HPLC capacity factors, Eadsforth, 1986)

Soluble in ether (Weast, 1986), and in other organic solvents and oils (ITII, 1986) Solubility in water: In mg/kg: 41 at 10 °C, 36 at 20 °C, 49 at 30 °C (shake flask-GC, Howe et al., 1987) 44.8 mg/L at 25 °C (shake flask-GC, Tam et al., 1996) 31.3 mg/L at 25 °C (shake flask-HPLC, Banerjee, 1984) 48.8 mg/L at 25 °C (Neely and Blau, 1985) 52 mg/L at 25 °C (shake flask-GC, Boyd et al., 1998) 34.57 mg/L at 25 °C (shake flask-UV spectrophotometry, Yalkowsky et al., 1979) 0.254 mM at 25 °C (generator column-GC, Miller et al., 1984) 64.5 mg/L at 30 °C (vapor equilibrium-GC, McNally and Grob, 1983, 1984) 28.6 mg/L 20 °C (Wilson et al., 1981) In mg/L: 32.9 at 5 °C, 28.5 at 15 °C, 36.5 at 25 °C, 39.8 at 35 °C, 46.5 at 45 °C (shake flask-GC,

Ma et al., 2001) Vapor density: 7.42 g/L at 25 °C, 6.26 (air = 1) Vapor pressure (mmHg): 0.4 at 25 °C (quoted, Mackay et al., 1982; Neely and Blau, 1985) 0.29 at 25 °C (quoted, Warner et al., 1987) Environmental fate: Biological. Under aerobic conditions, biodegradation products may include 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, and carbon dioxide (Kobayashi and Rittman, 1982). A mixed culture of soil bacteria or a Pseudomonas sp. transformed 1,2,4-trichlorobenzene to 2,4,5-and 2,4,6-trichlorophenol (Ballschiter and Scholz, 1980). When 1,2,4trichlorobenzene was statically incubated in the dark at 25 °C with yeast extract and settled domestic wastewater inoculum, significant biodegradation occurred, with gradual acclimation followed by a deadaptive process in subsequent subcultures. At a concentration of 5 mg/L, 54, 70, 59, and 24% losses were observed after 7, 14, 21, and 28-d incubation periods, respectively. At a concentration of 10 mg/L, only 43, 54, 14, and 0% were observed after 7, 14, 21, and 28-d incubation periods, respectively (Tabak et al., 1981). In activated sludge, <0.1% mineralized to carbon dioxide after 5 d (Freitag et al., 1985). In an enrichment culture derived from a contaminated site in Bayou d’Inde, LA, 1,2,4trichlorobenzene underwent reductive dechlorination to 1,3-and 1,4-dichlorobenzene at relative molar yields of 4 and 96%, respectively. The maximum dechlorination rate, based on the recommended Michaelis-Menten model, was 4.6 nM/d (Pavlostathis and Prytula, 2000). Surface Water. Estimated half-lives of 1,2,4-trichlorobenzene (0.5 µg/L) from an experimental marine mesocosm during the spring (8-16 °C), summer (20-22 °C), and winter (3-7 °C) were 22, 11, and 12 d, respectively (Wakeham et al., 1983). Photolytic. A carbon dioxide yield of 9.8% was achieved when 1,2,4-trichlorobenzene adsorbed on silica gel was irradiated with light (λ >290 nm) for 17 h (Freitag et al., 1985). The sunlight irradiation of 1,2,4-trichlorobenzene (20 g) in a 100-mL borosilicate glass-stoppered Erlenmeyer flask for 56 d yielded 9,770 ppm 2,4,5,2′,5′-pentachlorobiphenyl (Uyeta et al., 1976). When an aqueous solution containing 1,2,4-trichlorobenzene (45 µM) and a nonionic surfactant micelle (Brij 58, a polyoxyethylene cetyl ether) was illuminated by a photoreactor equipped with 253.7-nm monochromatic UV lamps for 48 min, the chloride ion concentration increased from 9.4 x 10-7 to 1.1 x 10-4 M and the pH decreased from 6.9 to 4.0. Intermediate products identified

1,3,5-trichlorobenzene. The photodecomposition half-life for this reaction, based on the first-order photodecomposition rate of 1.21 x 10-3/sec, is 9.6 min (Chu and Jafvert, 1994). A room temperature rate constant of 5.32 x 10-13 cm3/molecule⋅sec was reported for the vapor-phase reaction of 1,2,4-trichlorobenzene with OH radicals (Atkinson, 1985). Chemical/Physical. The hydrolysis half-life was estimated to be >900 yr (Ellington et al., 1988). At 70.0 °C and pH values of 3.10, 7.11, and 9.77, the hydrolysis half-lives were calculated to be 18.4, 6.6, and 5.9 d, respectively (Ellington et al., 1986). At influent concentrations of 1.0, 0.1, 0.01, and 0.001 mg/L, the GAC adsorption capacities were 157, 77.6, 38.4, and 19.0 mg/g, respectively (Dobbs and Cohen, 1980). Exposure limits: NIOSH REL: TWA ceiling 5 ppm (40 mg/m3); ACGIH TLV: ceiling 5 ppm (adopted). Symptoms of exposure: An irritation concentration of 40.00 mg/m3 in air was reported by Ruth (1986). Toxicity: EC10 and EC50 concentrations inhibiting the growth of alga Scenedesmus subspicatus in 96 h were 3.0 and 8.4 mg/L, respectively (Geyer et al., 1985). EC50 (96-h) and EC50 (3-h) concentrations that inhibit the growth of 50% of Selenastrum capricornutum population were 1.4 and 3.9 mg/L, respectively (Calamari et al., 1983). EC50 (48-h) for Daphnia magna 1.09 mg/L (Marchini et al., 1999), Pseudokirchneriella subcapitata 1.19 mg/L (Hsieh et al., 2006). IC50 (24-h) for Daphnia magna 1.2 mg/L (Calamari et al., 1983). LC50 (contact) for earthworm (Eisenia fetida) 27 µg/cm2 (Neuhauser et al., 1985). LC50 for red killifish 65 mg/L (Yoshioka et al., 1986). LC50 (14-d) for Poecilia reticulata 2.4 mg/L (Könemann, 1981). LC50 (96-h) for fathead minnows 2.9 mg/L (Veith et al., 1983), bluegill sunfish 3.4 mg/L (Spehar et al., 1982), Cyprinodon variegatus 21 ppm using natural seawater (Heitmuller et al., 1981); Palaemonetes pugio 0.54 mg/L (Clark et al., 1987). LC50 (72-h) for Cyprinodon variegatus 47 ppm (Heitmuller et al., 1981). LC50 (48-h) for Daphnia magna 50 mg/L (LeBlanc, 1980), Salmo gairdneri 1.95 mg/L, Brachydanio rerio 6.3 mg/L (Calamari et al., 1983), Cyprinodon variegatus >47 ppm (Heitmuller et al., 1981). LC50 (24-h) for Daphnia magna 110 mg/L (LeBlanc, 1980), Cyprinodon variegatus >47 ppm (Heitmuller et al., 1981). Acute oral LD50 for mice 300 mg/kg, rats 756 mg/kg (quoted, RTECS, 1985). Heitmuller et al. (1981) reported a NOEC of 15 ppm. Drinking water standard (final): MCLG: 70 µg/L; MCL: 70 µg/L. In addition, a DWEL of 50 µg/L was recommended (U.S. EPA, 2000). Uses: Solvent in chemical manufacturing; dyes and intermediates; dielectric fluid; synthetic transformer oils; lubricants; heat-transfer medium; insecticides; organic synthesis.