ABSTRACT
Note: According to Chevron Phillips Company’s (2006) Technical Data Sheet, >99 wt % propylbenzene typically contains 3-phenylpentane (≤ 1.0 wt %), indan (≤ 0.5 wt %), and isopropylbenzene (≤ 0.15 wt %). CASRN: 103-65-1; DOT: 2364; DOT label: Combustible liquid; molecular formula: C9H12; FW: 120.19; RTECS: DA8750000; Merck Index: 12, 8029 Physical state, color, and odor: Clear, colorless, mobile liquid with an odor similar to ethylbenzene or toluene. An odor threshold concentration of 3.8 ppbv was determined by a triangular odor bag method (Nagata and Takeuchi, 1990). Cometto-Muñiz and Cain (1994) reported an average nasal pungency threshold concentration of 1,487 ppmv. Melting point (°C): -99.5 (Weast, 1986) -101.75 (quoted, Mackay et al., 1982) Boiling point (°C): 159.2 (Weast, 1986) Density (g/cm3): 0.86313 at 20.00 °C, 0.85471 at 30.00 °C (Al-Kandary et al., 2006) Diffusivity in water (x 10-5 cm2/sec): 0.7368 at 20 °C using method of Hayduk and Laudie (1974) Dissociation constant, pKa: >14 (Schwarzenbach et al., 1993) Flash point (°C): 47 (Acros Organics, 2002) Lower explosive limit (%): 0.8 (Sax and Lewis, 1987) Upper explosive limit (%): 6 (Sax and Lewis, 1987) Heat of fusion (kcal/mol): 2.03-2.215 (Dean, 1987) Henry’s law constant (x 10-3 atm⋅m3/mol): 6.67 at 22 °C (dynamic stripping cell-MS, Karl et al., 2003) 6.706 at 22 °C (SPME-GC, Saraullo et al., 1997)
7.91 at 25 °C (gas purging method, Benzing et al., 1996) 4.35, 6.21, 8.37, 11.6, and 15.3 at 10, 15, 20, 25, and 30 °C, respectively (headspace-GC, Perlinger
et al., 1993) Interfacial tension with water (dyn/cm): 38.5 at 20 °C (Demond and Lindner, 1993) 35.24 at 20 °C, 34.66 at 40 °C, 33.73 at 60 °C, 32.46 at 80 °C (Jasper and Seitz, 1959) Ionization potential (eV): 8.713 (Lias, 1998) Soil organic carbon/water partition coefficient, log Koc: 2.87 (estuarine sediment, Vowles and Mantoura, 1987) Octanol/water partition coefficient, log Kow: 3.68 (Hansch et al., 1968) 3.69 (generator column-RPLC, Schantz and Martire, 1987; generator column-HPLC, Tewari et al.,
1982; generator column-HPLC/GC, Wasik et al., 1981, 1983) 3.70 at 10 °C, 3.72 at 15 °C, 3.74 at 20 °C (generator column-GC, DeVoe et al., 1981) 3.44 (shake flask-HPLC, Nahum and Horvath, 1980) 3.71, 3.72, 3.73 at 23 °C (generator column-HPLC/GC, Wasik et al., 1981) Solubility in organics: Miscible with alcohol and ether (Sax and Lewis, 1987) Solubility in water: 55 mg/L solution at 25 °C (shake flask-UV spectrophotometry, Andrews and Keefer, 1950a) 60.24 mg/L at 25 °C (shake flask-GC, Chiou et al., 1982) In µmol/L: 447 at 10.0 °C, 435 at 15.0 °C, 452 at 20.0 °C, 443 at 25.0 °C, 437 at 30.0 °C, 471 at
35.0 °C, 532 at 40.0 °C, 554 at 45.0 °C (coupled-column-LC, Owens et al., 1986) 434 µmol/L at 25.0 °C (generator column-HPLC, Tewari et al., 1982; generator column-
HPLC/GC, Wasik et al., 1981, 1983) 282 µmol/L in 0.5 M NaCl at 25 °C (Wasik et al., 1984) 388 at 15.0 °C, 423 at 25.0 °C, 455 at 35.0 °C, 528 at 45.0 °C (Sanemasa et al., 1982) 426, 425, 427, 432, and 445 µmol/L at 15, 20, 23, 25, and 30 °C, respectively (generator column-
HPLC/GC, Wasik et al., 1981) 70 mg/L at 25 °C (Krasnoshchekova and Gubergrits, 1975) 120 mg/L at 25 °C (shake flask-UV spectrophotometry, Klevens, 1950) 60 mg/kg at 15 °C (shake flask-turbidimetric, Fühner, 1924) 432 µmol/L at 25 °C (DeVoe et al., 1981) 110 mg/kg at 25 °C (shake flask-turbidimetric, Stearns et al., 1947) 239 µmol/L at 25.00 °C (Sanemasa et al., 1985) 415 µmol/L at 25.0 °C (Sanemasa et al., 1987) 7.35 x 10-6 at 25 °C (mole fraction, inert gas stripping-GC, Li et al., 1993) In mg/kg: 53 at 10 °C, 60 at 20 °C, 62 at 30 °C (shake flask-UV spectrophotometry, Howe et al.,
1987) In mM: 0.387 at 0.5 °C, 0.381 at 5.00 °C, 0.373 at 15.00 °C, 0.401 at 25.00 °C, 0.434 at 35.00 °C,
0.519 at 45.00 °C, 0.619 at 55.00 °C (HPLC, Dohányosová et al., 2001) In mole fraction (x 10-6) at 750 mmHg: 9.01 at 0.0 °C, 8.65 at 5.0 °C, 8.38 at 10.0 °C, 8.23 at 15.0
50.0 °C (equilibrium cell-UV spectrophotometry, Sawamura et al., 2001)
Vapor density: 4.91 g/L at 25 °C, 4.15 (air = 1) Vapor pressure (mmHg): 2.5 at 20 °C (quoted, Verschueren, 1983) 3.43 at 25 °C (quoted, Mackay et al., 1982) 8.4 at 40.00 °C (static method, Asmanova and Goral, 1980) Environmental fate: Biological. A Nocardia sp., growing on n-octadecane, biodegraded propylbenzene to phenylacetic acid (Davis and Raymond, 1981). Propylbenzene was cometabolized by a strain of Micrococcus cerificans to cinnamic acid (Pitter and Chudoba, 1990). Estimated half-lives of propylbenzene (0.8 µg/L) from an experimental marine mesocosm during the spring (8-16 °C), summer (20-22 °C), and winter (3-7 °C) were 19, 1.3, and 11 d, respectively (Wakeham et al., 1983). Photolytic. A rate constant of 3.7 x 10-9 L/molecule⋅sec was reported for the reaction of propylbenzene with OH radicals in the gas phase (Darnall et al., 1976). Similarly, a room temperature rate constant of 5.7 x 10-12 cm3/molecule⋅sec was reported for the vapor-phase reaction of propylbenzene with OH radicals (Atkinson, 1985). At 25 °C, a rate constant of 6.58 x 10-12 cm3/molecule⋅sec was reported for the same reaction (Ohta and Ohyama, 1985). Chemical/Physical. Propylbenzene will not hydrolyze because it does not contain a hydrolyzable functional group (Kollig, 1993). Toxicity: EC50 (72-h) for Selenastrum capricornutum 1.8 mg/L (Galassi et al., 1988). LC50 (96-h) for Salmo gairdneri 1.55 mg/L (Galassi et al., 1988). Acute oral LD50 for rats 6,040 mg/kg (quoted, RTECS, 1985). Source: Thomas and Delfino (1991) equilibrated contaminant-free groundwater collected from Gainesville, FL with individual fractions of three individual petroleum products at 24-25 °C for 24 h. The aqueous phase was analyzed for organic compounds via U.S. EPA approved test method 602. Average propylbenzene concentrations reported in water-soluble fractions of unleaded gasoline, kerosene, and diesel fuel were 246, 82, and 23 µg/L, respectively. When the authors analyzed the aqueous-phase via U.S. EPA approved test method 610, average propylbenzene concentrations in water-soluble fractions of unleaded gasoline, kerosene, and diesel fuel were generally lower, i.e., 210, 57, and 25 µg/L, respectively. Schauer et al. (1999) reported propylbenzene in a diesel-powered medium-duty truck exhaust at an emission rate of 100 µg/km. California Phase II reformulated gasoline contained propylbenzene at a concentration of 3.5 g/kg. Gas-phase tailpipe emission rates from gasoline-powered automobiles with and without catalytic converters were 0.83 and 97.9 mg/km, respectively (Schauer et al., 2002). Identified as one of 140 volatile constituents in used soybean oils collected from a processing plant that fried various beef, chicken, and veal products (Takeoka et al., 1996). Drinking water standard: No MCLGs or MCLs have been proposed (U.S. EPA, 1996). Uses: In textile dyeing and printing; solvent for cellulose acetate; manufacturing methylstyrene.
