ABSTRACT
CASRN: 84-66-2; molecular formula: C12H14O4; FW: 222.24; RTECS: TI1050000; Merck Index: 12, 7527 Physical state, color, odor, and taste: Clear, colorless, oily liquid with a mild, chemical odor. Bitter taste. Melting point (°C): -40.5 (quoted, Verschueren, 1983) Boiling point (°C): 298 (Weast, 1986) Density (g/cm3): 1.12276 at 14.89 °C, 1.11818 at 20.07 °C, 1.11381 at 25.00 °C, 1.10935 at 30.02 °C (De Lorenzi
et al., 1997) Diffusivity in water (x 10-5 cm2/sec): 0.59 at 20 °C using method of Hayduk and Laudie (1974) Flash point (°C): 140 (Windholz et al., 1983) 163 (open cup, Sax, 1984) Lower explosive limit (%): 0.7 at 186 °C (NFPA, 1984) Henry’s law constant (x 10-5 atm⋅m3/mol): At 25 °C: 5.01, 4.54, 4.78, 4.94, 2.21, and 2.44 at pH values of 2.96, 2.98, 6.18, 6.19, 8.98, and 9.00, respectively (Hakuta et al., 1977). Interfacial tension with water (dyn/cm at 20.5 °C): 16.27 (Donahue and Bartell, 1952) Bioconcentration factor, log BCF: 2.07 (bluegill sunfish, Veith et al., 1980) 2.31 (Chlorella pyrenoidosa, Yan et al., 1995) Soil organic carbon/water partition coefficient, log Koc: 1.84 (Broome County, NY composite soil), 1.99 (Conklin, NY sand) (Russell and McDuffie, 1986)
ow 2.35 at 20 °C (shake flask-UV spectrophotometry, Leyder and Boulanger, 1983) 2.42 (Ellington and Floyd, 1996) 2.24 at 25 °C (shake flask-HPLC, Howard et al., 1985) 1.40 (Veith et al., 1980) 2.82 (estimated using HPLC, DeKock and Lord, 1987) Solubility in organics: Soluble in acetone and benzene; miscible with ethanol, ether, esters, and ketones (U.S. EPA, 1985) Solubility in water: 928 mg/L at 20 °C (shake flask-UV spectrophotometry, Leyder and Boulanger, 1983) 1,080 mg/L at 25 °C (shake flask-HPLC, Howard et al., 1985) 1,200 ppm at 25 °C (Fukano and Obata, 1976) 0.1 wt % at 20 °C (Fishbein and Albro, 1972) 0.15 wt % at 20-25 °C (Fordyce and Meyer, 1940) 0.132, 0.120, and 0.137 wt % at 10.0, 20.0, and 30.0 °C, respectively (Schwarz and Miller, 1980) 680 mg/L at 25 °C (quoted, Russell and McDuffie, 1986) 1,113, 938, and 741 mg/L at 10, 25, and 35 °C, respectively (shake flask-tensiometry, Thomsen et
al., 2001) 804 mg/L at 25 °C (shake flask-UV spectrophotometry, Song et al., 2003) 896 mg/L at 25 °C (shake flask-GLC, Wolfe et al., 1980) Vapor density: 9.08 g/L at 25 °C, 7.67 (air = 1) Vapor pressure (x 10-3 mmHg): 50 at 70 °C (Fishbein and Albro, 1972) 1.65 at 25 °C (Howard et al., 1985) 2.1 at 25 °C (calculated from GC retention time data, Hinckley et al., 1990) 3.3 at 25 °C (extrapolated from vapor pressures determined at higher temperatures, Tesconi and
Yalkowsky, 1998) Environmental fate: Biological. A proposed microbial degradation mechanism is as follows: 4-hydroxy-3methylbenzyl alcohol to 4-hydroxy-3-methylbenzaldehyde to 3-methyl-4-hydroxybenzoic acid to 4-hydroxyisophthalic acid to protocatechuic acid to β-ketoadipic acid (Chapman, 1972). In anaerobic sludge, diethyl phthalate degraded as follows: monoethyl phthalate to phthalic acid to protocatechuic acid followed by ring cleavage and mineralization (Shelton et al., 1984). In a static-culture-flask screening test, diethyl phthalate showed significant biodegradation with rapid adaptation. The ester (5 and 10 mg/L) was statically incubated in the dark at 25 °C with yeast extract and settled domestic wastewater inoculum. After 7 d, 100% biodegradation was achieved (Tabak et al., 1981). Aerobic degradation of diethyl phthalate by acclimated soil and activated sewage sludge microbes was studied using an acclimated shake flask CO2 evolution test. After 28 d, loss of diethyl phthalate (primary degradation) was >99%, with a lag phase of 2.3 d, and ultimate biodegradation (CO2 evolution) was 95%. The half-life was 2.21 d (Sugatt et al., 1984). Photolytic. An aqueous solution containing titanium dioxide and subjected to UV radiation (λ >290 nm) produced hydroxyphthalates and dihydroxyphthalates as intermediates (Hustert and Moza, 1988).
