1,3-DICHLOROBENZENE

Cl Note: Commercial grades contain 65-85% 1,2-dichlorobenzene and the remaining 15-35% typically contains chlorobenzene, trichlorobenzenes, 1,2-dichlorobenzene and 1,4-dichlorobenzene. CASRN: 541-73-1; DOT: 1591; molecular formula: C6H4Cl2; FW: 147.00; RTECS: CZ4499000; Merck Index: 12, 3105 Physical state and color: Clear, colorless liquid with a disinfectant or musty-type odor. At 40 °C, the average odor threshold concentration and the lowest concentration at which an odor was detected were 170 and 177 µg/L, respectively. At 25 °C, the lowest concentration at which a taste was detected was 190 µg/L, respectively (Young et al., 1996). Melting point (°C): -24.70 (Martin et al., 1979) Boiling point (°C): 174 (Miller et al., 1984) 173.095 (Růžička et al., 1998) Density (g/cm3): 1.2881 at 20 °C, 1.2799 at 25 °C (quoted, Standen, 1964) 1.27718 at 30.00 °C (Rajasekar and Naidu, 1996) Diffusivity in water (x 10-5 cm2/sec): 0.82 at 20 °C using method of Hayduk and Laudie (1974) Flash point (°C): 63 (Aldrich, 1990) Lower explosive limit (%): 2.02 (estimated, Weiss, 1986) Upper explosive limit (%): 9.2 (estimated, Weiss, 1986) Entropy of fusion (cal/mol⋅K): 12.2 (Yalkowsky and Valvani, 1980) Heat of fusion (kcal/mol): 3.021 (Weast, 1986)

3.10 at 20 °C (batch equilibrium, Gan and Dupont, 1989) 3.6 (Pankow and Rosen, 1988) 2.63 at 25 °C (gas stripping-UV spectrophotometry, Warner et al., 1987) 4.63 at 37 °C (Sato and Nakajima, 1979) 1.8 at 20 °C (gas stripping-GC, Oliver, 1985) 2.94 at 25 °C (Hoff et al., 1993) 2.21, 2.31, 2.94, 2.85, and 4.22 at 10, 15, 20, 25, and 30 °C, respectively (EPICS, Ashworth et al.,

1988) 2.14 at 20.00 °C (inert gas stripping, Hovorka and Dohnal, 1997) Ionization potential (eV): 9.12 (Franklin et al., 1969) Bioconcentration factor, log BCF: 1.82 (bluegill sunfish) (Barrows et al., 1980; Veith et al., 1980) 2.62, 2.87 (rainbow trout, Oliver and Niimi, 1983) 1.99 (fathead minnow, Carlson and Kosian, 1987) 3.60 (Atlantic croakers), 3.86 (blue crabs), 3.25 (spotted sea trout), 3.40 (blue catfish) (Pereira et

al., 1988) Soil organic carbon/water partition coefficient, log Koc: 2.23 (log Kom for a Woodburn silt loam soil, Chiou et al., 1983) 4.60 (Niagara River sediments, Oliver and Charlton, 1984) Kd = 1.4 mL/g on a Cs+-kaolinite (Haderlein and Schwarzenbach, 1993) Octanol/water partition coefficient, log Kow: 3.38 (quoted, Leo et al., 1971) 3.43 (Miller et al., 1985) 3.48 (generator column-HPLC/GC, Wasik et al., 1981; generator column-GC, Miller et al., 1984;

generator column, Doucette and Andren, 1988) 3.53 at 25 °C (shake flask-GC, Watarai et al., 1982) 3.57 (generator column-HPLC, Garst, 1984) 3.72 at 13 °C, 3.55 at 19 °C, 3.48 at 28 °C, 3.42 at 33 °C (shake flask-GC, Opperhuizen et al.,

1988) 3.60 at 22 °C (shake flask-GC, Könemann et al., 1979) 3.525 at 25 °C (shake flask-GLC, de Bruijn et al., 1989) 3.46 (estimated from HPLC capacity factors, Hammers et al., 1982) 3.50 (shake flask-GC, Pereira et al., 1988) 3.65 (estimated from HPLC capacity factors, Eadsforth, 1986) Solubility in organics: Soluble in ethanol, acetone, ether, benzene, carbon tetrachloride, ligroin (U.S. EPA, 1985), and many organic solvents Solubility in water: 138 mg/L at 25 °C (shake flask-GC, Boyd et al., 1998) 143 mg/L at 25 °C (shake flask-HPLC, Banerjee, 1984) 133 mg/L at 25 °C (shake flask-LSC, Banerjee et al., 1980) 0.847 mM at 25 °C (generator column-GC, Miller et al., 1984) 0.01465 wt % at 23.5 °C (elution chromatography, Schwarz, 1980)

125.5 mg/L at 30 °C (vapor equilibrium-GC, McNally and Grob, 1983, 1984) 700 µmol/kg at 25.0 °C (shake flask-UV spectrophotometry, Vesala, 1974) In mg/L: 111 at 20 °C, 123 at 25 °C, 140 at 30 °C, 150 at 35 °C, 167 at 40 °C, 177 at 45 °C, 196 at

55 °C, 201 at 60 °C (Klemenc and Löw, 1930) In mg/L: 114 at 5.0 °C, 108 at 15.0 °C, 126 at 25.0 °C, 134 at 35.0 °C, 141 at 45.0 °C (shake

flask-GC, Ma et al., 2001) In mg/kg: 176 at 10 °C, 159 at 20 °C, 145 at 30 °C (shake flask-UV spectrophotometry, Howe et al., 1987) Vapor density: 6.01 g/L at 25 °C, 5.07 (air = 1) Vapor pressure (mmHg at 25 °C): 1.9 (Warner et al., 1987) 2.3 (quoted, Mackay et al., 1982) 2.15 (Banerjee et al., 1990) Environmental fate: Biological. When 1,3-dichlorobenzene was statically incubated in the dark at 25 °C with yeast extract and settled domestic wastewater inoculum, significant biodegradation with gradual acclimation was followed by a deadaptive process in subsequent subcultures. At a concentration of 5 mg/L, 59, 69, 39, and 35% losses were observed after 7, 14, 21, and 28-d incubation periods, respectively. At a concentration of 10 mg/L, percent losses were virtually unchanged. After 7, 14, 21, and 28-d incubation periods, percent losses were 58, 67, 31, and 33, respectively (Tabak et al., 1981). Photolytic. The sunlight irradiation of 1,3-dichlorobenzene (20 g) in a 100-mL borosilicate glass-stoppered Erlenmeyer flask for 56 d yielded 520 ppm trichlorobiphenyl (Uyeta et al., 1976). When an aqueous solution containing 1,3-dichlorobenzene (190 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, photoisomerization took place yielding 1,2-and 1,4dichlorobenzene as the principal products. The half-life for this reaction, based on the first-order photodecomposition rate of 1.40 x 10-3/sec, is 8.3 min (Chu and Jafvert, 1994). Peijnenburg et al. (1992) investigated the photodegradation of a variety of substituted aromatic halides using a Rayonet RPR-208 photoreactor equipped with 8 RUL 3,000-Ǻ lamps (250-350 nm). The reaction of 1,3-dichlorobenzene (initial concentration 10-5 M) was conducted in distilled water and maintained at 20 °C. Though no products were identified, the investigators reported photohydrolysis was the dominant transformation process. The measured pseudo-first-order reaction rate constant and corresponding half-life were 0.008/min and 92.3 min., respectively. Chemical/Physical. Anticipated products from the reaction of 1,3-dichlorobenzene with atmospheric ozone or OH radicals are chlorinated phenols, ring cleavage products, and nitro compounds (Cupitt, 1980). Based on an assumed base-mediated 1% disappearance after 16 d at 85 ºC and pH 9.70 (pH 11.26 at 25 ºC), the hydrolysis half-life was estimated to be >900 yr (Ellington et al., 1988). 1,3-Dichlorobenzene (0.17-0.23 mM) reacted with OH radicals in water (pH 8.7) at a rate of 5.0 x 109/M·sec (Haag and Yao, 1992). At influent concentrations of 1.0, 0.1, 0.01, and 0.001 mg/L, the GAC adsorption capacities at pH 5.1 were 118, 42, 15, and 5.1 mg/g, respectively (Dobbs and Cohen, 1980). Toxicity: EC50 (48-h) for Pseudokirchneriella subcapitata 2.68 mg/L (Hsieh et al., 2006). LC50 (14-d) for Poecilia reticulata 7.4 mg/L (Könemann, 1981).