AN EVALUATION OF THE AQUATIC HAZARD OF CUMENE (ISOPROPYL BENZENE)

Cumene manufacturers were required under a TSCA Section 4(a) test rule to evaluate the aquatic toxicity of cumene to daphnids, rainbow trout , mysid shrimp, and sheepshead minnows. Because of cumene's high volat ility (vapor pressure, 3.2 mm Hg at 20 degrees C), all tests were cond ucted under flowthrough conditions using a proportional diluter system . The 96-hr LC(50)s for rainbow trout, sheepshead minnow, and mysid sh rimp, based on mean measured concentrations, were 4.8, 4.7, and 1.3 mg /liter, respectively. The 48-hr daphnid EC(50) was 4.0 mg/liter. Altho ugh cumene is considered moderately toxic to aquatic organisms under r igorous laboratory conditions, its volatility and biodegradability gre atly reduce its hazard to the aquatic environment. (C) 1995 Academic P ress, Inc.