ABSTRACT
H3C CH CASRN: 74-99-7; molecular formula: C3H4; FW: 40.06; RTECS: UK4250000 Physical state, color, and odor: Colorless, flammable gas with a sweet odor Melting point (°C): -101.5 (Weast, 1986) Boiling point (°C): -23.2 (Weast, 1986) Density (g/cm3): 0.7062 at -50 °C (Weast, 1986) 0.678 at -27 °C (quoted, Verschueren, 1983) Lower explosive limit (%): 1.7 (NIOSH, 1997) Henry’s law constant (atm⋅m3/mol): 0.11 at 25 °C (Hine and Mookerjee, 1975) Ionization potential (eV): 10.36 ± 0.01 (Franklin et al., 1969) Soil organic carbon/water partition coefficient, log Koc: Unavailable because experimental methods for estimation of this parameter for aliphatic hydrocarbons are lacking in the documented literature Octanol/water partition coefficient, log Kow: 1.61 using method of Hansch et al. (1968) Solubility in organics: Soluble in alcohol, benzene, and chloroform (Weast, 1986) Solubility in water: 3,640 mg/L at 20 °C (quoted, Verschueren, 1983) Vapor density: 1.64 g/L at 25 °C, 1.38 (air = 1) Vapor pressure (mmHg): 3,952 at 20 °C, 5,244 at 30 °C (quoted, Verschueren, 1983) 4,310 at 25 °C (Wilhoit and Zwolinski, 1971) Environmental fate: Chemical/Physical. When passed through a cold solution containing hydrobromite ions, 1-
Combustion products include carbon monoxide, carbon dioxide, and water vapor. Exposure limits: NIOSH REL: TWA 1,000 ppm (1,650 mg/m3), IDLH 1,700 ppm; OSHA PEL: TWA 1,000 ppm; ACGIH TLV: TWA 1,000 ppm (adopted). Symptoms of exposure: An asphyxiant. Toxic at high concentrations (Patnaik, 1992). Uses: Chemical intermediate; specialty fuel.
