Comparison of short-term aquatic toxicity: Formulation vs active ingredients of pesticides

EC50 values for algae and water fleas and LC50 values for fish of formulated pesticide products from standardized short term toxicity tests have been compared with the corresponding values of the respective active ingredients (AI). The results suggest that toxicity tests conducted with the technical material will provide adequate information for estimating toxicological hazard of formulations to aquatic organisms. A preliminary hazard assessment performed by using the toxicity of the technical grade material divided by a species and formulation related factor of extrapolation uncertainty would allow a hazard assessment for the formulation with a high degree of reliability. Based on the presented data, this factor could be as low as 5 for green algae, 10 for water fleas, and 5 for fish without an unreasonable risk (2% or less) of substantially increased, environmentally relevant formulation toxicity. Such an approach would save considerable numbers of test animals and also allow improvement of formulations without unnecessary or even economically prohibitive replications of numerous tests.