ABSTRACT
Cl Note: δ-BHC is a steroisomer of γ-HCH, the active ingredient of lindane. CASRN: 319-86-8; DOT: 2761; DOT label: Poison; molecular formula: C6H6Cl6; FW: 290.83; RTECS: GV4550000 Physical state and odor: Solid crystals or fine platelets with a faint musty-like odor Melting point (°C): 141.5 (Lide, 1990) Boiling point (°C): 60 at 0.34 mmHg (quoted, Horvath, 1982) 60 at 0.50 mmHg (Lide, 1990) Density (g/cm3): 1.87 (Hawley, 1981) Diffusivity in water (x 10-5 cm2/sec): 0.50 at 20 °C using method of Hayduk and Laudie (1974) Heat of fusion (kcal/mol): 4.9, 5.3 (DSC, Plato, 1972) Henry’s law constant (x 10-7 atm·m3/mol): 2.5 at 20 °C (approximate - calculated from water solubility and vapor pressure) Bioconcentration factor, log BCF: 2.45 (Oncorhynchas mykiss, Devillers et al., 1996) Soil organic carbon/water partition coefficient, log Koc: 3.279 (Karickhoff, 1981) Octanol/water partition coefficient, log Kow: 4.14 at 22 °C (shake flask-GLC, Kurihara et al., 1973) 4.15 at 45 °C (shake flask-GLC, Paschke and Schüürmann, 1998) 3.85 at 25 °C (shake flask-GLC, Paschke and Schüürmann, 2000) Solubility in organics: Soluble in ethanol, benzene, and chloroform (Weast, 1986)
31.4 at 25 °C (extraction-GLC, Weil et al., 1974) At 28 °C: 8.64, 11.6 (0.05 µ particle size), 10.7, 15.7 (0.1 µ particle size) (Kurihara et al., 1973) 21.3 at 25 °C (Brooks, 1974) 7 at 20 °C (Worthing and Hance, 1991) Vapor pressure (x 10-5 mmHg): 1.7 at 20 °C (Balson, 1947) 3.52 at 25 °C (Banerjee et al., 1990) Environmental fate: Biological. Dehydrochlorination of δ-BHC by a Pseudomonas sp. under aerobic conditions was reported by Sahu et al. (1992). They also reported that when deionized water containing δ-BHC was inoculated with this species, the concentration of δ-BHC decreased to undetectable levels after 8 d with concomitant formation of chloride ions and δ-pentachlorocyclohexane. In four successive 7-d incubation periods, δ-BHC (5 and 10 mg/L) was recalcitrant to degradation in a settled domestic wastewater inoculum (Tabak et al., 1981). Chemical/Physical. δ-BHC dehydrochlorinates in the presence of alkali’s. Although no products were reported, the hydrolysis half-lives at pH values of 7 and 9 are 191 d and 11 h, respectively (Worthing and Hance, 1991). Toxicity: EC50 (48-h) for Daphnia pulex 680 µg/L (isomeric mixture, Johnon and Finley, 1980) LC50 (96-h) values of 2.83, 1.58, and 0.84 mg/L for Poecilia reticulata, Brachydanio rerio, and Paracheirodon axelrodi, respectively (Oliverira-Filho and Paumgarten, 1997); for isomeric mixture: cutthroat trout 9 µg/L, rainbow trout 18 µg/L, goldfish 348 µg/L, fathead minnow 125 µg/L, channel catfish 105 µg/L, bluegill sunfish 67 µg/L, largemouth bass 41 µg/L (Johnson and Finley). LC50 (72-h) values of 3.27, 1.58, and 1.42 mg/L for Poecilia reticulata, Brachydanio rerio, and Paracheirodon axelrodi, respectively (Oliverira-Filho and Paumgarten, 1997). LC50 (48-h) values of 3.79, 1.87, and 2.19 mg/L for Poecilia reticulata, Brachydanio rerio, and Paracheirodon axelrodi, respectively (Oliverira-Filho and Paumgarten, 1997). LC50 (24-h) values of 4.05, 2.64, and 2.59 mg/L for Poecilia reticulata, Brachydanio rerio, and Paracheirodon axelrodi, respectively (Oliverira-Filho and Paumgarten, 1997). Acute oral LD50 for rats 1,000 mg/kg (quoted, RTECS, 1985). Use: Insecticide.
