ABSTRACT
CASRN: 606-20-2; DOT: 1600 (liquid); 2038 (solid); molecular formula: C7H6N2O4; FW: 182.14; RTECS: XT1925000 Physical state and color: Pale yellow, orange, brown or reddish rhombic crystals. Odor threshold concentration in water is 100 ppb (quoted, Keith and Walters, 1992). Melting point (°C): 66 (Weast, 1986) Boiling point (°C): 285 (Maksimov, 1968) Density (g/cm3): 1.2833 at 111 °C (Weast, 1986) Diffusivity in water (x 10-5 cm2/sec): 0.76 at 20 °C using method of Hayduk and Laudie (1974) Flash point (°C): 206.7 (calculated, Weiss, 1986) Henry’s law constant (x 10-7 atm⋅m3/mol): 2.17 (quoted, Howard, 1989) Soil organic carbon/water partition coefficient, log Koc: 1.79 using method of Karickhoff et al. (1979) Octanol/water partition coefficient, log Kow: 2.10 at 25 °C (shake flask-UV spectrophotometry, Nakagawa et al., 1992) Solubility in organics: Soluble in ethanol (Weast, 1986) and many other organic solvents including chloroform and carbon tetrachloride. Solubility in water: 180 mg/L mg/L (Mabey et al., 1982) ≈ 300 mg/L (quoted, Mills et al., 1985) Vapor pressure (x 10-4 mmHg): 3.5 at 20 °C (quoted, Howard, 1989) 5.67 at 25 °C (Banerjee et al., 1990)
Biological. When 2,6-dinitrotoluene 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 deadaptive process in subsequent subcultures. At a concentration of 5 mg/L, 82, 55, 47, and 29% losses were observed after 7, 14, 21, and 28-d incubation periods, respectively. At a concentration of 10 mg/L, only 57, 49, 35, and 13% were observed after 7, 14, 21, and 28-d incubation periods, respectively (Tabak et al., 1981). Under anaerobic and aerobic conditions, a sewage inoculum degraded 2,6-dinitrotoluene to aminonitrotoluene (Hallas and Alexander, 1983). 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. The bacterium utilized 2,6-dinitrotoluene as a source of nitrogen yielding two compounds: 2-amino-6-toluene and 6,6′-dinitro-2,2′-azoxytoluene. 2-Hydroxylamino-6-nitrotoluene and subsequent formation of 2,6-dihydroxyaminotoluene were reported as intermediate products of 2,6-dinitrotoluene metabolism by Clostridium acetobutylicum. 2,6-Diaminotoluene was reported as the end product (Hughes et al., 1999). Photolytic. Simmons and Zepp (1986) estimated the photolytic half-life of 2,6-dinitrotoluene in surface water to range from 2 to 17 h. Low et al. (1991) reported that the nitro-containing compounds (e.g., 2,4-dinitrophenol) undergo degradation by UV light in the presence of titanium dioxide yielding ammonium, carbonate, and nitrate ions. By analogy, 2,6-dinitrotoluene should degrade forming identical ions. Chemical/Physical. 2,6-Dinitrotoluene will not hydrolyze (Kollig, 1993). At influent concentrations of 1.0, 0.1, 0.01, and 0.001 mg/L, the GAC adsorption capacities were 145, 70, 33, and 16 mg/g, respectively (Dobbs and Cohen, 1980). Exposure limits (mg/m3): TWA: 1.5, IDLH: 200 (Weiss, 1986). Toxicity: EC50 (15-min) for Photobacterium phosphoreum 9.78 mg/L (Yuan and Lang, 1997). IC50 (24-h) for river bacteria 63.2 mg/L (Yuan and Lang, 1997). Acute oral LD50 for mice 621 mg/kg, rats 177 mg/kg (quoted, RTECS, 1985). Drinking water standard: No MCLGs or MCLs have been proposed although 2,6-dinitrotoluene has been listed for regulation (U.S. EPA, 1996). In addition, a DWEL of 40 µg/L was recommended (U.S. EPA, 2000). Uses: Organic synthesis; propellant additive; manufacture of explosives; intermediate in the manufacture of polyurethanes.
