ABSTRACT
Note: Reagent grades of 2,4-toluene diisocyanate usually contains minor quantities of the isomer 2,6-toluene diisocyanate. This compound is present in greater concentrations in technical grades. CASRN: 584-84-9; DOT: 2078; DOT label: Poison; molecular formula: C9H6N2O2; FW: 174.15; RTECS: CZ6300000; Merck Index: 12, 9668 Physical state, color, and odor: Clear, colorless to light yellow liquid with a pungent, fruity odor. Odor threshold concentration in air is 2.14 ppmv (Leonardos et al., 1969). Melting point (°C): 19.5-21.5 (Windholz et al., 1983) 20-21 (Dean, 1987) Boiling point (°C): 251 (Windholz et al., 1983) Density (g/cm3): 1.2244 at 20 °C (Windholz et al., 1983) Flash point (°C): 127 (NFPA, 1984) Lower explosive limit (%): 0.9 (NFPA, 1984) Upper explosive limit (%): 9.5 (NIOSH, 1997) Soil organic carbon/water partition coefficient, log Koc: Not applicable - reacts with water Octanol/water partition coefficient, log Kow: Not applicable - reacts with water Solubility in organics: Miscible with acetone, benzene, carbon tetrachloride, diglycol monomethyl ether, ether, kerosene (Windholz et al., 1983), and chlorobenzene (quoted, Keith and Walters, 1992)
Not applicable - reacts with water Vapor density: 7.12 g/L at 25 °C, 6.01 (air = 1) Vapor pressure (mmHg): 0.0105 at 20.0 °C, 0.025 at 30.0 °C, 0.062 at 40.0 °C, 4.2 at 103.3 °C (gas saturation technique, Frensdorff and Adams, 1975) Environmental fate: Chemical/Physical. Slowly reacts with water forming carbon dioxide and polyureas (NIOSH, 1997; Windholz et al., 1983). Exposure limits: NIOSH REL: IDLH 2.5 ppm; OSHA PEL: ceiling 0.02 ppm (0.14 mg/m3); ACGIH TLV: TWA 5 ppb, STEL 20 ppb (adopted). Symptoms of exposure: Vapors may cause bronchitis, headache, sleeplessness, pulmonary edema, wheezing, shortness of breath, and chest congestion. Ingestion may cause coughing, vomiting, and gastrointestinal pain. Contact with skin may cause nausea, vomiting, abdominal pain, dermatitis, and skin sensitization (Patnaik, 1992). An irritation concentration of 4.00 mg/m3 in air was reported by Ruth (1986). Toxicity: Acute oral LD50 for rats 5,800 mg/kg, wild birds 100 mg/kg (quoted, RTECS, 1985). LC50 values reported for fathead minnows at exposure time of 24, 72, and 96 h were 194.9, 172.1, and 164.5 mg/L, respectively (Curtis et al., 1978). LC50 (inhalation) for guinea pigs 13 ppm/4-h, mice 10 ppm/4-h, rats 14 ppm/4-h (quoted, RTECS, 1985). Uses: Manufacturing of polyurethane foams and other plastics; cross-linking agent for nylon 6.
