ACUTE TOXICITY OF FIREFIGHTING CHEMICAL FORMULATIONS TO 4 LIFE STAGESOF FATHEAD MINNOW

Laboratory studies were conducted with four early life stages of fathe ad minnow, Pimephales promelas, to determine the acute toxicity of fiv e firefighting chemical formulations in standardized soft and hard wat er. Egg, fry, 30-day posthatch, and 60-day post-hatch life stages were tested with three fire retardants (Fire-Trol GTS-R, Fire-Trol LCG-R, and Phos-Chek D75-F) and two fire-suppressant foams (Phos-Chek WD-881 and Ansul Silv-Ex). Fry were generally the most sensitive life stage t ested, whereas the eggs were the least sensitive life stage. Formulati on toxicity was greater in hard water than in soft water for all life stages tested. Fire-suppressant foams were more toxic than the fire re tardants. The 96-hr LC(50)s derived for fathead minnows were rank orde red from the most toxic to the least toxic formulation as follows: Pho s-Chek WD-881 (13-32 mg/liter) > Silv-Ex (19-32 mg/liter) > Fire-Trol GTS-R (135-787 mg/liter) > Phos-Chek D75-F (168-2250 mg/liter) > Fire- Trol LCG-R (519-6705 mg/liter) (ranges are the lowest and highest 96-h r LC(50) for each formulation). (C) 1996 Academic Press, Inc.