Tech. form colorless or pale yellow crystal. M.p. 64-71C (peak 67C), ( varies with even small-1%-change in isomer ratio. In water 51.5 (5C), 93.4 (25C), 270.6 (35C) (all in ug/l, pH7). In isopropanol 11.5, xylene 349.8, dichloromethane 3878, acetone 2102, ethyl acetate 1427, petroleum ether 13.1 (all in mg/ml, 20C). Stable to 150C，；to air and sunlight; in neutral and slight acidic media; epidermises in presence of base, hydrolysed in strongly alkaline media. DT50 (extrapolated) 50 d (pH 3, 5. 6), 40 d (pH 7), 20 d (pH 8), 15 d (pH 9) (all at 25C).