Acute Toxicity of Diisopropylmethyl Phosphonate and Dicyclopentadiene to Aquatic Organisms.

Abstract : The acute toxicity of diisopropylmethyl phosphonate (DIMP) and dicyclopentadiene (DCPD) was studied utilizing aquatic organisms representing several trophic levels in an aquatic ecosystem. DCPD was found to be approximately 10X more toxic than DIMP. The eggs and 7-day old fry of the fathead minnow were the life stages least susceptible to DCPD and DIMP, respectively. Increasing hardness and pH 8.0 appeared to decrease slightly the toxicity of DIMP while the toxicity of DCPD was not significantly altered by varying water quality parameters. Generally, aging of solutions had little affect on toxicity of DCPD. A 50% decrease in toxicity to bluegill was observed for DIMP solutions allowed to age for 96 hours. Essentially no bioconcentration (1X) was observed for bluegill continually exposed to C(14) DIMP, and the estimated maximum bioconcentration factor for C(14) DCPD was 53X.