ABSTRACT
Cl O Cl CASRN: 542-88-1; DOT: 2249; DOT label: Poison and flammable liquid; molecular formula: C2H4Cl2O; FW: 114.96; RTECS: KN1575000; Merck Index: 12, 3119 Physical state, color, and odor: Colorless liquid with a suffocating odor Melting point (°C): -41.5 (Weast, 1986) Boiling point (°C): 104 (Weast, 1986) 106 (Fishbein, 1979) Density (g/cm3): 1.328 at 15 °C (Weast, 1986) 1.315 at 20 °C (Fishbein, 1979) Diffusivity in water: Not applicable - reacts with water Flash point (°C): <19 (Sax and Lewis, 1987) Henry’s law constant (atm⋅m3/mol): Not applicable - reacts with water Soil organic carbon/water partition coefficient, log Koc: Not applicable - reacts with water Octanol/water partition coefficient, log Kow: Not applicable - reacts with water Solubility in organics: Soluble in alcohol, ether (Weast, 1986), benzene (Hawley, 1981), and other solvents including acetone and chloroform. Solubility in water: Not applicable - reacts with water (Fishbein, 1979) Vapor density: 4.70 g/L at 25 °C, 3.97 (air = 1) Vapor pressure (mmHg): 30 at 22 °C (Dreisbach, 1952)
Chemical/Physical. Reacts rapidly with water forming HCl and formaldehyde (Fishbein, 1979; Tou et al., 1974). Tou et al. (1974) reported a hydrolysis half-life of 38 sec for sym-dichloromethyl ether at 20 °C. Anticipated products from the reaction of sym-dichloromethyl ether with ozone or OH radicals in the atmosphere, excluding the decomposition products formaldehyde and HCl, are chloromethyl formate and formyl chloride (Cupitt, 1980). Exposure limits: Known human carcinogen. ACGIH TLV: TWA 1 ppb (adopted). Symptoms of exposure: Irritation of eyes, nose, and throat (Patnaik, 1992). Toxicity: The LC50 (14-d) inhalation value for rats and hamsters following a single 7-h exposure was 7 ppm (Drew et al., 1975). Acute oral LD50 for rats is 210 mg/kg (quoted, RTECS, 1985). Source: sym-Dichloromethyl ether may form as an intermediate by-product when form-aldehyde reacts with chloride ions under acidic conditions (Frankel et al., 1974; Tou and Kallos, 1974a; Travenius, 1982). Tou and Kallos (1974) reported that the reactants (formaldehyde and chloride ions) must be in concentrations of mg/L to form sym-dichloromethyl ether at concentrations of µg/L. Chloromethyl methyl ether may contain 1 to 8% sym-dichloromethyl ether as an impurity (Environment Canada, 1993a). Uses: Intermediate in anionic-exchange quaternary resins; chloromethylating agent.
