BENZO[e]PYRENE

CASRN: 192-97-2; DOT: 2811; molecular formula: C20H12; FW: 252.32; RTECS: DJ4200000; Merck Index: 12, 1135 Physical state: Crystalline, solid, prisms, or plates. Benzo[e]pyrene is sensitive to ultraviolet light and may degrade into diones. Melting point (°C): 178.8 (Murray et al., 1974) 179 (Bjørseth, 1983) Boiling point (°C): 493 (Bjørseth, 1983) Density (g/cm3): 0.8769 at 20 °C (Windholz et al., 1983) Diffusivity in water (x 10-5 cm2/sec): 0.50 at 20 °C using method of Hayduk and Laudie (1974) Dissociation constant, pKa: >14 (Schwarzenbach et al., 1993) Entropy of fusion (cal/mol⋅K): 10.1 (Hinckley et al., 1990) Henry’s law constant (x 10-7 atm⋅m3/mol): 4.84 at 25 °C (approximate - calculated from water solubility and vapor pressure) Ionization potential (eV): 7.41 (Lias et al., 1998) 7.62 (Cavalieri and Rogan, 1985) Bioconcentration factor, log BCF: 4.56 (freshwater isopod A. aquaticus, van Hattum and Montanes, 1999) Soil organic carbon/water partition coefficient, log Koc: 7.20 (Broman et al., 1991) 6.19 (San Francisco, CA mudflat sediments, Maruya et al., 1996) 5.45-7.98 based on 50 sediment determinations; average value = 6.59 (Hawthorne et al., 2006)

ow 6.44 (estimated from TLC retention time correlation, DeVoogt et al., 1990) Solubility in organics: Slightly soluble in methanol (Patnaik, 1992) Solubility in water: In nmol/L: 12.9 at 8.6 °C, 14.2 at 14.0 °C, 17.6 at 17.0 °C, 15.6 at 17.5 °C, 18.2 at 20.0 °C, 19.0 at

20.2 °C, 20.1 at 23.0 °C, 21.2 at 23.2 °C, 25.5 at 29.2 °C, 27.0 at 31.7 °C. In seawater: 3.32 ng/kg at 25 °C. In NaCl solution (salinity = 30 g/kg): 8.2 at 8.9 °C, 8.8 at 10.8 °C, 1.01 at 15.6 °C, 1.04 at 19.2 °C, 1.13 at 21.7 °C, 1.35 at 25.3 °C, 1.42 at 27.1 °C, 1.66 at 30.2 °C (shake flask-UV spectrophotometry, Schwarz, 1977)

29 nmol/L at 25 °C (shake flask-UV spectrophotometry, Barone et al., 1967) 3.5 µg/L at 27 °C (shake flask-nephelometry, Davis et al., 1942) Vapor pressure (x 10-9 mmHg): 2.4 (McVeety and Hites, 1988) 5.54 at 25 °C (extrapolated from vapor pressure determined at higher temperatures, Pupp et al.,

1974) 5.55 at 25 °C (Murray et al., 1974) 644 at 25 °C (subcooled liquid vapor pressure calculated from GC retention time data, Hinckley et

al., 1990) Environmental fate: Photolytic. Schwarz and Wasik (1976) reported a fluorescence quantum yield of ≈ 0.3 for benzo[e]pyrene in water. Chemical/Physical. Benzo[e]pyrene will not hydrolyze because it has no hydrolyzable functional group. Source: The concentration of benzo[e]pyrene in coal tar and the maximum concentration reported in groundwater at a mid-Atlantic coal tar site were 3,700 and 0.0034 mg/L, respectively (Mackay and Gschwend, 2001). Detected in 8 diesel fuels at concentrations ranging from 0.047 to 2.1 mg/L with a mean value of 0.113 mg/L (Westerholm and Li, 1994). Identified in Kuwait and South Louisiana crude oils at concentrations of 0.5 and 2.5 ppm, respectively (Pancirov and Brown, 1975). Benzo[e]pyrene is produced from the combustion of tobacco and petroleum fuels. It also occurs in low octane gasoline (0.18-0.87 mg/kg), high octane gasoline (0.45-1.82 mg/kg), used motor oil (92.2-278.4 mg/kg), asphalt (≤0.0052 wt %), coal tar pitch (≤0.70 wt %), cigarette smoke (3 µg/1,000 cigarettes), and gasoline exhaust (quoted, Verschueren, 1983). Lehmann et al. (1984) reported a benzo[e]pyrene concentration of 0.02 mg/g in a commercial anthracene oil. 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 particle-phase emission rates of benzo[e]pyrene were 0.459 mg/kg of pine burned, 0.231 mg/kg of oak burned, and 0.212 mg/kg of eucalyptus burned. Particle-phase tailpipe emission rates from gasoline-powered automobiles with and without catalytic converters were 0.015 and 38.2 µg/km, respectively (Schauer et al., 2002). Uses: Chemical research.