Edward E. Little James N. Huckins James F. Fairchild 1992 <p><span>This study determined the acute and chronic toxicity of the organophosphate insecticide fonofos to standard freshwater aquatic organisms under laboratory conditions. Fonofos was acutely toxic to bluegill </span><i class="EmphasisTypeItalic ">(Lepomis macrochirus), Daphnia (D. magna)</i><span>, and midge </span><i class="EmphasisTypeItalic ">(Chironomous riparius)</i><span> at 5.3, 2.7, and 39 μg/L, respectively. Three fonofos formulations (technical, 94.8% A.I.; 20G, field granular 20% A.I.; and 4E, field liquid 4#/gal A.I.) exhibited similar acute toxicities to bluegill. Exposure to fonofos delayed reproduction and decreased the intrinsic rate of increase of </span><i class="EmphasisTypeItalic ">Daphnia</i><span> during 21-d chronic exposure at the lowest tested concentration (0.08 μg/L). The no observable effect concentration (NOEC) for </span><i class="EmphasisTypeItalic ">Daphnia</i><span> survival was 0.42 μg/L; 0% survival occurred at the lowest observable effect concentration (LOEC) of 1.45 μg/L. The NOEC for midge emergence was 3.42 μg/L; only 34% emergence occurred at the LOEC of 8.24 μg/L. Chronic 30-d exposure of juvenile bluegills decreased growth and survival at 5.65 μg/L (LOEC), but no effects occurred at 2.33 μg/L (NOEC). The relative hazard of fonofos to aquatic life is similar to other carbamate and organophosphate corn insecticides.</span></p> application/pdf 10.1007/BF00212556 en Springer Aquatic hazard assessment of the organophosphate insecticide fonofos article