ABSTRACT
CASRN: 77-78-1; DOT: 1595; DOT label: Corrosive; molecular formula: C2H6O4S; FW: 126.13; RTECS: WS8225000; Merck Index: 12, 3305 Physical state, color, and odor: Colorless, oily liquid with an onion-like odor. Melting point (°C): -31.8 (Du Pont, 1999a) Boiling point (°C): 188.8 (Du Pont, 1999a) Density (g/cm3): 1.333 at 15.6 °C (Du Pont, 1999a) 1.3283 at 20 °C (Weast, 1986) Diffusivity in water (x 10-5 cm2/sec): 0.91 at 20 °C using method of Hayduk and Laudie (1974) Flash point (°C): 83 (closed cup), 116 (open cup) (Du Pont, 1999a) Henry’s law constant (x 10-6 atm⋅m3/mol): 2.96 at 20 °C (approximate - calculated from water solubility and vapor pressure) Soil organic carbon/water partition coefficient, log Koc: 0.03 (Verschueren, 1996) Octanol/water partition coefficient, log Kow: -1.24 (quoted, Mercer et al., 1990) Solubility in organics: Soluble in 1,4-dioxane, and aromatic hydrocarbons (Windholz et al., 1983) Solubility in water (g/L): 28 at 18 °C (quoted, Windholz et al., 1983) 28 at 20 °C (Du Pont, 1999a) Vapor density: 4.35 (air = 1) (Windholz et al., 1983) Vapor pressure (mmHg): 0.5 at 20 °C (Weast, 1986) 0.7 at 25 °C, 1.1 at 38 °C (Du Pont, 1999a)
Chemical/Physical. Hydrolyzes in water (half-life = 1.2 h) to methanol and sulfuric acid (Robertson and Sugamori, 1966) via the intermediate methyl sulfuric acid (Du Pont, 1999a) Exposure limits: Potential occupational carcinogen. NIOSH REL: TWA 0.1 ppm (0.5 mg/m3), IDLH 7 ppm; OSHA PEL: TWA 1 ppm (5 mg/m3); ACGIH TLV: TWA 0.1 ppm (adopted). Toxicity: LC50 (96-h static bioassay) for bluegill sunfish 7.5 mg/L, Menidia beryllina 15 mg/L (quoted, Verschueren, 1983). Acute oral LD50 for mice 140 mg/kg, rats 205 mg/kg (quoted, RTECS, 1985). Uses: In organic synthesis as a methylating agent.
