ABSTRACT
NO2 CASRN: 99-65-0; DOT: 1597; DOT label: Poison; molecular formula: C6H4N2O4; FW: 168.11; RTECS: CZ7350000 Physical state and color: White to yellowish crystals Melting point (°C): 90 (Weast, 1986) 90.20 (Martin et al., 1979) Boiling point (°C): 300-303 (Windholz et al., 1983) Density (g/cm3): 1.5751 at 18 °C (Weast, 1986) 1.368 at 89 °C (Aldrich, 1990) Diffusivity in water (x 10-5 cm2/sec): 0.79 at 20 °C using method of Hayduk and Laudie (1974) Flash point (°C): 150 (NIOSH, 1997) Entropy of fusion (cal/mol⋅K): 11.4 (Andrews et al., 1926) Henry’s law constant (x 10-8 atm⋅m3/mol): 4.90 at 25 °C (thermodynamic method-GC/UV spectrophotometry, Altschuh et al., 1999) Bioconcentration factor, log BCF: 1.87 (3-d exposure, Poecilia reticulata, Deneer et al., 1987) Ionization potential (eV): 10.43 (NIOSH, 1997) Soil organic carbon/water partition coefficient, log Koc: Kd = 1,800 mL/g on a Cs+-kaolinite (Haderlein and Schwarzenbach, 1993) Octanol/water partition coefficient, log Kow: 1.52 at 25 °C, 1.48 at 60 °C (shake flask-UV spectrophotometry, Kramer and Henze, 1990) Solubility in organics: Soluble in acetone, ether, pyrimidine (Weast, 1986), alcohol (27 g/L), pyridine (3,940 g/kg at 20-
and toluene. Solubility in water: 3.13 g/L at 100 °C (quoted, Windholz et al., 1983) 532.8 mg/L at 25 °C (Leiga and Sarmousakis, 1966) 469 mg/L at 15 °C, 3,200 mg/L at 100 °C (quoted, Verschueren, 1983) 654 mg/kg at 30 °C (shake flask-interferometer, Gross and Saylor, 1931) 4.67 mM at 35 °C (Hine et al., 1963) >21.4 g/kg at 20-25 °C (shake flask-gravimetric, Dehn, 1917) 5.12 mmol/kg at 25.0 °C (shake flask-UV spectrophotometry, Vesala, 1974) Vapor pressure (mmHg): 8.15 x 10-4 at 35 °C (Hine et al., 1963) Environmental fate: Biological. Under anaerobic and aerobic conditions using a sewage inoculum, 1,3dinitrobenzene degraded to nitroaniline (Hallas and Alexander, 1983). In activated sludge inoculum, following a 20-d adaptation period, no degradation was observed (Pitter, 1976). Photolytic. Low et al. (1991) reported that the nitro-containing compounds (e.g., 2,4dinitrophenol) undergo degradation by UV light in the presence of titanium dioxide yielding ammonium, carbonate, and nitrate ions. By analogy, 1,3-dinitrobenzene should degrade forming identical ions. Chemical/Physical. Releases toxic nitrogen oxides when heated to decomposition (Sax and Lewis, 1987). 1,3-Dinitrobenzene will not hydrolyze in water (Kollig, 1993). Although no products were identified, 1,3-dinitrobenzene (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 0.0339/min, the half-life was 20.4 min (Agrawal and Tratnyek, 1996). Exposure limits (mg/m3): NIOSH REL: TWA 1, IDLH 50; OSHA PEL: TWA 1; ACGIH TLV: TWA 0.15 ppm for all isomers (adopted). Toxicity: EC50 (15-min) for Photobacterium phosphoreum 4.03 mg/L (Yuan and Lang, 1997). IC50 (24-h) for river bacteria 8.62 mg/L (Yuan and Lang, 1997). LC50 (96-h) for fathead minnows 12.7 mg/L (Spehar et al., 1982). Acute oral LD50 for rats 83 mg/kg, wild birds 42 mg/kg (quoted, RTECS, 1985). Subchronic NOEC for Selenastrum capricornutum 260 µg/L (vn der Schalie, 1983). Drinking water standard: No MCLGs or MCLs have been proposed, however, a DWEL of 5 µg/L was recommended (U.S. EPA, 2000). Uses: Organic synthesis; dyes.
