1-BUTENE

Note: According to Chevron Phillips Company’s (2004) product literature, 99.6% 1-butene contains n-butane (0.2 wt %) and trans-2-butene (0.2 wt %). Solution may contain other impurities and possible inhibitors. CASRN: 106-98-9; DOT: 1012; molecular formula: C4H8; FW: 56.11; Merck Index: 12, 1548 Physical state, color, and odor: Clear, colorless, very flammable gas with a weak propaone or butane-like odor. A faint odor was recognized at a concentration range of 21.5-25.4 ppb (quoted, Verschueren, 1983). Ruth (1986) reported that the low odor and high odor threshold concentrations were identical at a concentration of 54.96 mg/m3. Melting point (°C): -185.3 (Weast, 1986) Boiling point (°C): -6.3 (Weast, 1986) Density (g/cm3): 0.595 at 20 °C (Chevron Phillips, 2004) 0.577 at 25 °C (Lide, 1990) Diffusivity in water (x 10-5 cm2/sec): 0.91 at 20 °C using method of Hayduk and Laudie (1974) Dissociation constant, pKa: >14 (Schwarzenbach et al., 1993) Flash point (°C): -112 (estimated, Chevron Phillips, 2004) -79 (open cup, Hawley, 1981) Lower explosive limit (%): 1.6 (NFPA, 1984) Upper explosive limit (%): 10.0 (NFPA, 1984) Heat of fusion (kcal/mol): 0.92 (Dean, 1987) Henry’s law constant (atm⋅m3/mol): 0.25 at 25 °C (Hine and Mookerjee, 1975) Ionization potential (eV): 9.26 (Collin and Lossing, 1959)

oc Unavailable because experimental methods for estimation of this parameter for aliphatic hydrocarbons are lacking in the documented literature Octanol/water partition coefficient, log Kow: 2.40 (shake flask, Hansch and Leo, 1979) Solubility in organics: Soluble in alcohol, benzene, and ether (Weast, 1986) Solubility in water: 222 mg/kg at 25 °C (shake flask-GC, McAuliffe, 1966) Vapor density: 2.29 g/L at 25 °C, 1.94 (air = 1) Vapor pressure (mmHg): 1,978 at 21.12 °C (cell and transducer system, Steele et al., 1976) 2,230 at 25 °C (Wilhoit and Zwolinski, 1971) 2,592 at 30 °C, 4,476 at 50 °C (Beattie and Marple, 1950) Environmental fate: Biological. Biooxidation of 1-butene may occur yielding 3-buten-1-ol, which may oxidize to give 3-butenoic acid (Dugan, 1972). Washed cell suspensions of bacteria belonging to the genera Mycobacterium, Nocardia, Xanthobacter, and Pseudomonas and growing on selected alkenes metabolized 1-butene to 1,2-epoxybutane (Van Ginkel et al., 1987). Photolytic. Products identified from the photoirradiation of 1-butene with nitrogen dioxide in air are epoxybutane, 2-butanone, propanal, ethanol, ethyl nitrate, carbon monoxide, carbon dioxide, methanol, and nitric acid (Takeuchi et al., 1983). The following rate constants were reported for the reaction of 1-butene and OH radicals in the atmosphere: 1.0 x 10-17 cm3/molecule⋅sec (Bufalini and Altshuller, 1965); 2.70 x 10-11 cm3/molecule⋅sec (Atkinson et al., 1979); 3.14 x 10-11 cm3/molecule⋅sec (Atkinson, 1990; Sabljić and Güsten, 1990). Reported photooxidation reaction rate constants for the reaction of 1-butene and ozone are 1.23 x 10-17, 1.0 x 10-17, 1.03 x 10-17 cm3/molecule⋅sec (Adeniji et al., 1981). Based on the reaction of 1-butene and OH radicals gas phase, the atmospheric lifetime was estimated to be 5.5 h in summer sunlight. Chemical/Physical. Complete combustion in air yields carbon dioxide and water. Incomplete combustion will generate carbon monoxide. Hydrolysis in water is not expected to be signicant because 1-butene is very volatile. Symptoms of exposure: Narcotic at high concentrations (Patnaik, 1992) Source: In exhaust of gasoline-powered engines (1.8 vol % of total exhaust hydrocarbons) (quoted, Verschueren, 1983). Detected in California Phase II reformulated gasoline at a concentration of 170 mg/kg (Schauer et al., 2002). Schauer et al. (2001) measured organic compound emission rates for volatile organic compounds, gas-phase semi-volatile organic compounds, and particle-phase organic compounds from the residential (fireplace) combustion of pine, oak, and eucalyptus. The gas-phase emission rate of 1-butene was 90.7 mg/kg of pine burned. Emission rates of 1-butene were not measured during the combustion of oak and eucalyptus. Reported as an impurity (0.1 wt %) in 99.4 wt % trans-2-butene (Chevron Phillips, 2004).