1,1-DICHLOROETHANE

CASRN: 75-34-3; DOT: 2362; DOT label: Flammable liquid; molecular formula: C2H4Cl2; FW: 98.96; RTECS: KI0175000; Merck Index: 12, 3856 Physical state, color, and odor: Clear, colorless, oily liquid with a chloroform-like odor Melting point (°C): -97.4 (Dean, 1973) Boiling point (°C): 57.3 (Weast, 1986) Density (g/cm3): 1.1757 at 20 °C (Weast, 1986) 1.1830 at 15 °C, 1.60010 at 30 °C (quoted, Standen, 1964) Diffusivity in water (x 10-5 cm2/sec): 0.98 at 20 °C using method of Hayduk and Laudie (1974) Flash point (°C): -16.7 (NIOSH, 1997) 13.3 (McGovern, 1943) Lower explosive limit (%): 5.4 (NIOSH, 1997) Upper explosive limit (%): 11.4 (NIOSH, 1997) Heat of fusion (kcal/mol): 1.881 (quoted, Riddick et al., 1986) Henry’s law constant (x 10-3 atm⋅m3/mol): 4.3 (Pankow and Rosen, 1988) 5.45 at 25 °C (gas stripping-GC, Warner et al., 1987) 5.56 at 25 °C (EPICS, Gossett, 1987) 9.43 at 37 °C (Sato and Nakajima, 1979) 3.68, 4.54, 5.63, 6.25, and 7.76 at 10, 15, 20, 25, and 30 °C, respectively (EPICS, Ashworth et al.,

1988) 4.6, 7.0, and 10.2 at 20, 30, and 40 °C, respectively (Tse et al., 1992) Distilled water: 1.63, 2.06, 2.03, 3.75, and 5.05 at 2.0, 6.0, 10.0, 18.2, and 25.0 °C, respectively;

natural seawater: 2.42 and 5.80 at 6.0 and 25.0 °C, respectively (EPICS, Dewulf et al., 1995) 2.70 at 10.00 °C, 4.60 at 20.00 °C, 6.94 at 30.00 °C, 8.40 at 35.00 °C, 9.98 at 40.00 °C, 11.6 at

45.00 °C, 13.2 at 50.00 °C (inert gas stripping, Hovorka and Dohnal, 1997)

1.72 at 2 °C, 2.37 at 6 °C, 2.80 at 10 °C, 4.31 at 18 °C, 5.85 at 25 °C, 7.51 at 30 °C, 10.4 at 40 °C,

14.5 at 50 °C, 18.8 at 60 °C (EPICS-SPME-GC, Görgényi et al., 2002) 4.84 at 25 °C (batch air stripping-GC, Bobadilla et al., 2003) Ionization potential (eV): 11.06 (NIOSH, 1997) Soil organic carbon/water partition coefficient, log Koc: 1.46 (Ellington et al., 1993) 1.66 (Jury et al., 1990) 1.79 (Roy et al., 1987) 1.43, 1.46, 1.43, 1.48, 1.50, 1.49, and 1.55 at 2.3, 3.8, 6.2, 8.0, 13.5, and 18.6 at 25.0 °C,

respectively, for a Leie River (Belgium) clay (Dewulf et al., 1999a) Octanol/water partition coefficient, log Kow: 1.82, 1.66, and 1.68 at 25, 35, and 50 °C, respectively (GLC, Bhatia and Sandler, 1995) 1.70, 1.69, 1.74, 1.73, 1.78, and 1.75 at 2.2, 6.0, 10.0, 14.1, 18.7, and 24.8 °C, respectively (shake

flask-GC, Dewulf et al., 1999a) 1.79 (Hansch and Leo, 1979) Solubility in organics: Miscible with ethanol (U.S. EPA, 1985) Solubility in water: 6,560, 5,590, 5,500, and 5,400 mg/kg at 0, 10, 20, and 30 °C, respectively (Rex, 1906) 5,060 mg/kg at 25 °C (shake flask-interferometer, Gross, 1929) 4,589 mg/L at 30 °C (vapor equilibrium-GC, McNally and Grob, 1984) 4,834.4 mg/L at 30 °C (vapor equilibrium-GC, McNally and Grob, 1983) In mg/kg: 7,435 at 10 °C, 7,137 at 20 °C, 6,130 at 30 °C (shake flask-GC, Howe et al., 1987) Vapor density: 4.04 g/L at 25 °C, 3.42 (air = 1) Vapor pressure (mmHg): 234 at 25 °C, 270 at 30 °C (quoted, Verschueren, 1983) 227 at 25 °C (quoted, Howard, 1990) Environmental fate: Biological. 1,1-Dichloroethane showed significant degradation with gradual adaptation in a static-culture flask-screening test (settled domestic wastewater inoculum) conducted at 25 °C. At concentrations of 5 and 10 mg/L, percent losses after 4 wk of incubation were 91 and 83, respectively. At a substrate concentration of 5 mg/L, 19% was lost due to volatilization after 10 d (Tabak et al., 1981). Under anoxic conditions, indigenous microbes in uncontaminated sediments produced vinyl chloride (Barrio-Lage et al., 1986). Surface Water. The following volatilization half-lives were reported for 1,1-dichloroethane: 6 to 9 d in a pond, 5 to 8 d in a lake, 24 to 32 h in a river (Smith et al., 1980). Photolytic. Titanium dioxide suspended in an aqueous solution and irradiated with UV light (λ = 365 nm) converted 1,1-dichloroethane to carbon dioxide at a significant rate (Matthews, 1986). The initial photodissociation product of 1,1-dichloroethane was reported to be chloroacetyl chloride (U.S. EPA, 1975). This compound is readily hydrolyzed to HCl and chloroacetic acid

The rate constant for the reaction of 1,1-dichloroethane and OH radicals in the atmosphere at 300 K is 1.6 x 10-11 cm3/molecule⋅sec (Hendry and Kenley, 1979). At 296 K, a photooxidation rate constant of 2.6 x 10-13 cm3/molecule⋅sec was reported for the reaction with OH radicals resulting in a half-life of 1.5 months (Howard and Evenson, 1976). Chemical/Physical. A glass bulb containing air and 1,1-dichloroethane degraded outdoors to carbon dioxide and HCl. The half-life for this reaction was 17 wk (Pearson and McConnell, 1975). Hydrolysis of 1,1-dichloroethane under alkaline conditions yielded vinyl chloride, acetaldehyde, and HCl (Kollig, 1993). The reported hydrolysis half-life at 25 °C and pH 7 is 61.3 yr (Jeffers et al., 1989). The evaporation half-life of 1,1-dichloroethane (1 mg/L) from water at 25 °C using a shallowpitch propeller stirrer at 200 rpm at an average depth of 6.5 cm was 32.2 min (Dilling, 1977). At influent concentrations of 1.0, 0.1, 0.01, and 0.001 mg/L, the GAC adsorption capacities at pH 5.3 were 1.8, 0.52, 0.15, and 0.04 mg/g, respectively (Dobbs and Cohen, 1980). Exposure limits: NIOSH REL: TWA 100 ppm (400 mg/m3), IDLH 3,000 ppm; OSHA PEL: TWA 100 ppm; ACGIH TLV: TWA 100 ppm (adopted). Symptoms of exposure: May cause irritation of eyes, nose, throat, and skin (Patnaik, 1992) Toxicity: EC50 (48-h) for Pseudokirchneriella subcapitata 44.83 mg/L (Hsieh et al., 2006). LC50 (7-d) for Poecilia reticulata 202 mg/L (Könemann, 1981). LC50 (96-h) for bluegill sunfish 550 mg/L, Menidia beryllina 480 mg/L (quoted, Verschueren, 1983). Acute oral LD50 for rats 725 mg/kg (quoted, RTECS, 1985). Drinking water standard: No MCLGs or MCLs have been proposed (U.S. EPA, 2000). Uses: Extraction solvent; insecticide, oils, and fats; chemical intermediate for 1,1,1trichloroethane; in rubber cementing, fabric spreading, and fire extinguishers; formerly used as an anesthetic; organic synthesis.