ABSTRACT
NO2 CASRN: 99-99-0; DOT: 1664; DOT label: Poison; molecular formula: C7H7NO2; FW: 137.14; RTECS: XT3325000; Merck Index: 12, 6748 Physical state, color, and odor: Yellowish crystals with a weak, aromatic odor Melting point (°C): 51.5 (Lenchitz and Velicky, 1970) 51.4 (Gross et al., 1933) 51.9 (Stull, 1947) Boiling point (°C): 233.25 (Deisbach and Shrader, 1949) Density (g/cm3): 1.1038 at 75 °C (Weast, 1986) 1.286 at 20 °C (quoted, Verschueren, 1983) Diffusivity in water (x 10-5 cm2/sec): 0.81 at 20 °C using method of Hayduk and Laudie (1974) Dissociation constant, pKa: 11.27 (Perrin, 1972) Flash point (°C): 107 (NIOSH, 1997) Lower explosive limit (%): 1.6 (NIOSH, 1997) Entropy of fusion (cal/mol⋅K): 12.6 (Tsonopoulos and Prausnitz, 1971) Heat of fusion (kcal/mol): 4.10 (Tsonopoulos and Prausnitz, 1971) Henry’s law constant (x 10-6 atm⋅m3/mol): 5.64 at 25 °C (thermodynamic method-GC/UV spectrophotometry, Altschuh et al., 1999) Ionization potential (eV): 9.46 (Lias, 1998)
oc Kd = 54 mL/g on a Cs+-kaolinite (Haderlein and Schwarzenbach, 1993) Octanol/water partition coefficient, log Kow: 2.37 at 25 °C (shake flask-UV spectrophotometry, Fujita et al., 1964) 2.42 (quoted, Leo et al., 1971) Solubility in organics: Soluble in acetone, alcohol, benzene, ether (Weast, 1986), and chloroform (Windholz et al., 1983) Solubility in water: 442 mg/kg at 30 °C (shake flask-interferometer, Gross et al., 1933) At 20 °C: 210, 183, 187, and 177 µmol/L in doubly distilled water, Pacific seawater, artificial
seawater, and 35% NaCl, respectively (modified shake flask method-fluorometry, Hashimoto et al., 1984)
In mg/L: 179 at 10.00 °C, 242 at 20.00 °C, 322 at 30 °C (shake flask-UV spectrophotometry, Beneš and Dohnal, 1999)
Vapor pressure (mmHg): 0.1 at 20 °C (NIOSH, 1997) 0.22 at 30 °C (quoted, Verschueren, 1983) 0.004633 at 23.886 °C, 0.005484 at 26.042 °C, 0.007070 at 28.029 °C, 0.007818 at 30.207 °C
(Knuden effusion method, Lenchitz and Velicky, 1970) Environmental fate: Biological. Under anaerobic conditions using a sewage inoculum, 3-and 4-nitrotoluene both degraded to toluidine (Hallas and Alexander, 1983). Robertson et al. (1992) reported that toluene dioxygenases from Pseudomonas putida F1 and Pseudomonas sp. Strain JS 150 oxidized the methyl group forming 2-methyl-5-nitrophenol and 3-methyl-6-nitrocatechol. Chemical. Though no products were identified, 4-nitrotoluene (1.5 x 10-5 M) was reduced by iron metal (33.3 g/L acid washed 18 to 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 0.0335/min, the half-life was 20.7 min (Agrawal and Tratnyek, 1996). Exposure limits: NIOSH REL: TWA 2 ppm (11 mg/m3), IDLH 200 ppm; OSHA PEL: TWA 5 ppm (30 mg/m3); ACGIH TLV: TWA 2 ppm (adopted). Toxicity: LC50 (48-h) for red killifish 537 mg/L (Yoshioka et al., 1986). Acute oral LD50 for mice 1,231 mg/kg, rats 1,960 mg/kg (quoted, RTECS, 1985). Uses: Manufacture of dyes, nitrobenzoic acids, toluidines, etc.
