ABSTRACT
ENDOSULFAN SULFATE Synonyms: 6,7,8,9,10,10-Hexachloro-1,5,5a,6,9,9a-hexahydro-3,3-dioxide; 6,9-Methano-2,4,3benzodioxathiepin; Thiodan sulfate; UN 2761.
O S
O
Cl Cl
ClCl
Cl Cl
O
O CASRN: 1031-07-8; DOT: 2761; DOT label: Poison; molecular formula: C9H6Cl6O4S; FW: 422.92 Physical state: Solid Melting point (°C): 181 (quoted, Keith and Walters, 1992) 198-201 (Ali, 1978) Diffusivity in water (x 10-5 cm2/sec): 0.44 at 20 °C using method of Hayduk and Laudie (1974) Henry’s law constant (x 10-5 atm⋅m3/mol): 4.64 at 25 °C (approximate - calculated from water solubility and vapor pressure) Soil organic carbon/water partition coefficient, log Koc: 3.690, 3.510, 3.539, 3.452 (various European soils, Gawlik et al., 2000) Octanol/water partition coefficient, log Kow: 3.66 (Ali, 1978) Solubility in water: 117 ppb (Ali, 1978) Vapor pressure (mmHg): 9.75 x 10-6 at 25 °C (subcooled liquid vapor pressure calculated from GC retention time data, Hinckley et al., 1990) Environmental fate: Biological. A mixed culture of soil microorganisms biodegraded endosulfan sulfate to endosulfan ether, endosulfan-α-hydroxy ether, and endosulfan lactone (quoted, Verschueren, 1983). Indigenous microorganisms obtained from a sandy loam degraded endosulfan sulfate (a metabolite of α-and β-endosulfan) to endosulfan diol. This diol was converted to endosulfan αhydroxy ether and trace amounts of endosulfan ether and both were degraded to endosulfan lactone (Miles and Moy, 1979). Using settled domestic wastewater inoculum, endosulfan sulfate (5 and 10 mg/L) did not degrade after 28 d of incubation at 25 °C (Tabak et al., 1981). Plant. In tobacco leaves, endosulfan sulfate was formed to α-endosulfan, which subsequently hydrolyzed to endosulfan diol (Chopra and Mahfouz, 1977). Chemical/Physical. Eighty-eight percent of endosulfan sulfate was recovered from an aqueous solution after 33 d. Based on this data, a hydrolytic half-life of 178 d was reported (Ali, 1978).
