CHLOROPICRIN

Cl CASRN: 76-06-2; DOT: 1580; DOT label: Poison; molecular formula: CCl3NO2; FW: 164.38; RTECS: PB6300000; Merck Index: 12, 2208 Physical state, color, and odor: Colorless to pale yellow, oily liquid with a sharp, penetrating odor. Odor threshold concentration is 0.78 ppm (quoted, Amoore and Hautala, 1983). Melting point (°C): -64.5 (Weast, 1986) -64 (Worthing and Hance, 1991) Boiling point (°C): 111.8 (Weast, 1986) 112.4 (Worthing and Hance, 1991) Density (g/cm3): 1.6558 at 20 °C, 1.6483 at 25 °C (Windholz et al., 1983) Diffusivity in water (x 10-5 cm2/sec): 0.89 at 20 °C using method of Hayduk and Laudie (1974) Henry’s law constant (x 10-3 atm⋅m3/mol at 25 °C): 2.06 (static headspace-GC, Kawamoto and Urano, 1989) 2.44 (static headspace-GC, Welke et al., 1998) Interfacial tension with water (dyn/cm at 20 °C): 32.3 (estimated, CHRIS, 1984) Soil organic carbon/water partition coefficient, log Koc: 0.82 using method of Chiou et al. (1979) Octanol/water partition coefficient, log Kow: 1.03 (RP-HPLC, Kawamoto and Urano, 1989) Solubility in organics: Miscible with acetone, benzene, carbon disulfide, carbon tetrachloride, ether, and methanol (Worthing and Hance, 1991) Solubility in water: 2,270 mg/L at 0 °C (Gunther et al., 1968) 1.621 g/L at 25 °C (quoted, Windholz et al., 1983)

6.72 g/L at 25 °C, 5.67 (air = 1) Vapor pressure (mmHg): 16.9 at 20 °C, 33 at 30 °C (quoted, Verschueren, 1983) 23.8 at 25 °C (quoted, Kawamoto and Urano, 1989) 18.3 at 20 °C (Meister, 1988) Environmental fate: Biological. Four Pseudomonas sp., including Pseudomonas putida (ATCC culture 29607) isolated from soil, degraded chloropicrin by sequential reductive dechlorination. The proposed degradative pathway is chloropicrin → nitrodichloromethane → nitrochloromethane → nitromethane + small amounts of carbon dioxide. In addition, a highly water soluble substance tentatively identified as a peptide was produced by a nonenzymatic mechanism (Castro et al., 1983). Photolytic. Photodegrades under simulated atmospheric conditions to phosgene and nitrosyl chloride. Photolysis of nitrosyl chloride yields chlorine and nitrous oxide (Moilanen et al., 1978; Woodrow et al., 1983). When aqueous solution of chloropicrin (10-3 M) is exposed to artificial UV light (λ <300 nm), protons, carbon dioxide, hydrochloric and nitric acids are formed (Castro and Belser, 1981). Chemical/Physical. Releases very toxic fumes of chlorides and nitrogen oxides when heated to decomposition (Sax and Lewis, 1987). Reacts with alcoholic sodium sulfite solutions and ammonia to give methanetrisulfonic acid and guanidine, respectively (Sittig, 1985). Exposure limits: NIOSH REL: TWA 0.1 ppm (0.7 mg/m3), IDLH 2 ppm; OSHA PEL: 0.1 ppm; ACGIH TLV: TWA 0.1 ppm (adopted). Symptoms of exposure: An irritation concentration of 2.10 mg/m3 in air was reported by Ruth (1986). Toxicity: LC50 (inhalation) for mice 1,500 mg/m3/10-min (quoted, RTECS, 1985). Acute oral LD50 for rats 250 mg/kg (quoted, RTECS, 1985). Drinking water standard: No MCLGs or MCLs have been proposed although chloropicrin has been listed for regulation (U.S. EPA, 1996). Uses: Disinfecting cereals and grains; fumigant and soil insecticide; dyestuffs; odorant in methyl bromide fungicide; rat exterminator; organic synthesis; war gas.