ABSTRACT
Cl CASRN: 100-00-5; DOT: 1578; DOT label: Poison; molecular formula: C6H4ClNO2; FW: 157.56; RTECS: CZ1050000; Merck Index: 12, 2203 Physical state, color, and odor: Yellow, crystalline solid with a sweet odor Melting point (°C): 83.6 (Weast, 1986) Boiling point (°C): 242 (Weast, 1986) Density (g/cm3): 1.520 at 18 °C (quoted, Verschueren, 1983) Diffusivity in water (x 10-5 cm2/sec): 0.76 at 20 °C using method of Hayduk and Laudie (1974) Flash point (°C): 127.3 (NIOSH, 1997) Entropy of fusion (cal/mol⋅K): 7.98 (Marchidan and Ciopec, 1978) Henry’s law constant (x 10-6 atm⋅m3/mol): 4.90 at 25 °C (thermodynamic method-GC/UV spectrophotometry, Altschuh et al., 1999) Ionization potential (eV): 9.96 (NIOSH, 1997) Bioconcentration factor, log BCF: 2.00 (Oncorhynchus mykiss, Devillers et al., 1996) 2.00 (Salmo gairdneri, Niimi et al., 1989) Soil organic carbon/water partition coefficient, log Koc: Kd = 44 mL/g on a Cs+-kaolinite (Haderlein and Schwarzenbach, 1993) Octanol/water partition coefficient, log Kow: 2.39 at 25 °C (shake flask-UV spectrophotometry, Fujita et al., 1964; shake flask-GC, Niimi et al., 1989; shake flask-UV spectrophotometry, Kramer and Henze, 1990)
Soluble in acetone and alcohol (Weast, 1986) Solubility in water: 2,877 µmol/L at 20 °C (Eckert, 1962) 3.40 g/L at 20 °C (Hafkenscheid and Tomlinson, 1983) 153 mg/L at 10.00 °C, 209 mg/L at 20.00 °C, 274 mg/L at 30 °C (shake flask-UV
spectrophotometry, Beneš and Dohnal, 1999) As mole fraction: 2.57 x 10-5 at 20 °C (shake flask-RPLC, Hafkenscheid and Tomlinson, 1981) Vapor pressure (mmHg): 0.0233 at 25.00 °C (effusion method, DePablo, 1976) Environmental fate: Biological. Under aerobic conditions, the yeast Rhodosporidium sp. metabolized pchloronitrobenzene to 4-chloroacetanilide and 4-chloro-2-hydroxyacetanilide as final major metabolites. Intermediate compounds identified include 4-chloronitrosobenzene, 4-chlorophenylhydroxylamine, and 4-chloroaniline (Corbett and Corbett, 1981). Under continuous flow conditions involving feeding, aeration, settling, and reflux, a mixture of p-chloronitrobenzene and 2,4-dinitrochlorobenzene was reduced 61-70% after 8-13 d by Arthrobacter simplex, a microorganism isolated from industrial waste. A similar experiment was conducted using two aeration columns. One column contained A. simplex, the other a mixture of A. simplex and microorganisms isolated from soil (Streptomyces coelicolor, Fusarium sp., probably aquaeductum and Trichoderma viride). After 10 d, 89.5-91% of the nitro compounds was reduced. p-Chloronitrobenzene was reduced to 4-chloroaniline and six unidentified compounds (Bielaszczyk et al., 1967). Photolytic. An aqueous solution containing p-chloronitrobenzene and a titanium dioxide (catalyst) suspension was irradiated with UV light (λ >290 nm). 2-Chloro-5-nitrophenol was the only compound identified as a minor degradation product. Continued irradiation caused additional degradation yielding carbon dioxide, water, hydrochloric and nitric acids (Hustert et al., 1987). Irradiation of p-chloronitrobenzene in air and nitrogen produced 4-chloro-2-nitrophenol and 4chlorophenol, respectively (Kanno and Nojima, 1979). Chemical. Although no products were identified, p-chloronitrobenzene (1.5 x 10-5 M) was reduced by iron metal (33.3 g/L acid washed 18-20 mesh) in a carbonate buffer (1.5 x 10-2 M) at pH 5.9 and 15 °C. Based on the pseudo-first-order disappearance rate of 0.0336/min, the half-life was 20.6 min (Agrawal and Tratnyek, 1996). Exposure limits (mg/m3): Potential occupational carcinogen. NIOSH REL: IDLH 100; OSHA PEL: TWA 1. Symptoms of exposure: Anoxia, unpleasant taste, anemia (NIOSH, 1997) Toxicity: EC50 (15-min) for Photobacterium phosphoreum 18.1 mg/L (Yuan and Lang, 1997). IC50 (24-h) for river bacteria 27.4 mg/L (Yuan and Lang, 1997). Acute oral LD50 for mice 650 mg/kg, rats 420 mg/kg (quoted, RTECS, 1985). LD50 (skin) for rats 16 gm/kg (quoted, RTECS, 1985). Uses: Intermediate for dyes; rubber and agricultural chemicals; manufacture of p-nitrophenol.
