ABSTRACT

NO2 CASRN: 118-96-7; DOT: 1356; DOT label: Class A explosive; molecular formula: C7H5N3O6; FW: 227.13; RTECS: XU0175000; Merck Index: 12, 9860 Physical state, color, and odor: Colorless to light yellow, odorless monoclinic crystals Melting point (°C): 82 (Weast, 1986) 80.1 (Windholz et al., 1983) Boiling point (°C): Explodes at 240 (Weast, 1986) Density (g/cm3): 1.654 at 20 °C (Weast, 1986) Diffusivity in water (x 10-5 cm2/sec): 0.68 at 20 °C using method of Hayduk and Laudie (1974) Flash point (°C): Explodes (NIOSH, 1997) Ionization potential (eV): 10.59 (Lias et al., 1998) Bioconcentration factor, log BCF (L/kg): 0.23-0.96 (Pimephales promelas, Yoo et al., 2006) Soil organic carbon/water partition coefficient, log Koc: 2.48 using method of Kenaga and Goring (1980) Octanol/water partition coefficient, log Kow: 2.25 using method of Kenaga and Goring (1980) Solubility in organics: Soluble in acetone, benzene, ether, and pyrimidine (Weast, 1986) Solubility in water (mg/L): 90-92 at 13.6 °C, 86 at 13.9 °C, 115 at 23.0 °C, 191 at 33.3 °C, 266 at 42.6 °C, 427 at 51.8 °C,

641 at 61.0 °C (Phelan and Barnett, 2001)

20.1 °C, 208.5-213.1 at 36 °C, 219.5 at 37.7 °C, 216.5 at 37.8 °C; at pH 5.7: 54.4 at 2.3 °C, 47.4 at 2.6 °C, 47.9-59.1 at 4.2 °C, 96.7-100.6 at 20 °C, 97.5-100.4 at 20.1 °C, 208.5-215.2 at 36 °C, 230.2 at 37.7 °C, 2227.3at 37.8 °C; At pH 6.2, 56.2 at 2.3 °C, 55.2 at 2.6 °C, 56.1-57.4 at 4.2 °C, 96.3-101.2 at 20 °C, 94.6-99.8 at 20.1 °C, 212.2-216.5 at 36 °C, 230.4 at 37.7 °C, 234.7 at 37.8 °C (HPLC-UV spectrophotometry, Lynch et al., 2001)

At 6 °C: 52.5 at pH 3.7, 51.3 at pH 6.9; 64.0 at 12 °C (pH 6.9); at 13 °C: 72.2 at pH 3.7, 64.4 at pH 6.9; at 20 °C: 86.2 at pH 4.2, 88.5 at pH 7.3, 96.8 at pH 9.2, 95.7 at pH 9.4, 91.2 at pH 10.1; at 21 °C: 74.5 at pH 3.5, 82.5 at pH 6.8, 88.2 at pH 9.1; at 25 °C: 101.6 at pH 3.5, 100.5 at pH 6.8, 110.5 at pH 9.1; at 42 °C: 204.9 at pH 4.0, 204.5 at pH 6.8, 167.6 at pH 9.3 (Ro et al., 1996)

68 at 4 °C, 94 at 20 °C, 154 at 30 °C, 253 at 40 °C; in seawater (33.1 g of salt/kg of seawater): 56 at 4 °C, 86 at 20 °C, 121 at 30 °C, 207 at 40 °C (Prak and O’Sullivan, 2006)

Vapor pressure (x 10-3 mmHg): 0.2 at 20 °C (NIOSH, 1997) 4.26 at 54.76 °C, 2.557 at 72.49 °C, 4.347 at 76.06 °C (Knuden effusion method, Lenchitz and

Velicky, 1970) Environmental fate: Biological. 4-Amino-2,6-dinitrotoluene and 2-amino-4,6-dinitrotoluene, detected in contaminated groundwater beneath the Hawthorne Naval Ammunition Depot, NV, were reported to have formed from the microbial degradation of 2,4,6-trinitrotoluene (Pereira et al., 1979). 2,4,6Trinitrotoluene (220 µM) degraded in aerobic sludge containing molasses (3.3 g/L). Though 2,4,6trinitrotoluene disappeared completed in 15 h, only 0.1% was mineralized to carbon dioxide. Under aerobic conditions, intermediate compounds reported in the biotransformation of 2,4,6trinitrotoluene to 2,4,6-triaminotoluene were 4-hydroxyamino-2,6-dinitrotoluene, 4-amino-2,6-dinitrotoluene, 2,4-diamino-6-nitrotoluene, 2-hydroxyamino-4,6-dinitrotoluene, 2-amino-4,6dinitrotoluene, 2,6-diamino-4-nitrotoluene. Under abiotic conditions (pH 2 to 3), the following hydroxylated compounds formed: 2-hydroxy-4,6-diaminotoluene, 2,6-dihydroxy-4-aminotoluene, 4-hydroxy-2,6-diaminotoluene, 2,4-dihydroxy-6-aminotoluene, and 2,4,6-trihydroxytoluene. Under biotic conditions (pH 7.0), two azo derivatives were produced: 2,2′,4,4′-tetraamino-6,6′- azotoluene and 2,2′,6,6′-tetraamino-4,4′-azotoluene (Hawari et al., 1998). Haïdour and Ramos (1996) analyzed the degradation products of 2,4,6-trinitrotoluene, 2,4dinitrotoluene, and 2,6-dinitrotoluene by the bacterium Pseudomonas sp. clone A under aerobic conditions. Reduced 2,4,6-trinitrotoluene metabolites, which were not used as a nitrogen source by this bacterium, were 2-hydroxyamino-4,6-dinitrotoluene, 4-hydroxyamino-2,6-dinitrotoluene, and 2,4-diamino-6-nitrotoluene. Chemical. Although no products were identified, 2,4,6-trinitrotoluene (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 0.0330/min, the half-life was 21.0 min (Agrawal and Tratnyek, 1996). 2,4,6-Trihydroxytoluene was detected after 2,4,6trinitrotoluene in water was heated to 100 °C (Hawari et al., 1998). Will detonate upon heating (NIOSH, 1997). 2,4,6-Trinitrotoluene will not hydrolyze in water because it does not contain a hydrolyzable funcational group. Exposure limits (mg/m3): NIOSH 0.5, IDLH 500; OSHA PEL: TWA 1.5; ACGIH TLV: TWA 0.1 (adopted). Symptoms of exposure: May cause dermatitis, cyanosis, gastritis, sneezing, sore throat, muscular pain, somnolence, tremor, convulsions, and asplastic anemia (Patnaik, 1992)

LC50 (96-h) for Xenopus laevis 16.7 µM (Saka, 2004). Acute oral LD50 in mice 660 mg/kg, rats 795 (quoted, RTECS, 1985). Source: Generated as a waste from munitions and defense industries, leaching from unexploded land mines. Drinking water standard: No MCLGs or MCLs have been proposed, however, a DWEL of 20 µg/L was recommended (U.S. EPA, 2000). Uses: High explosive; intermediate in dyestuffs and photographic chemicals.