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 form ulated pesticide products from standardized short term toxicity tests have been compared with the corresponding values of the respective act ive ingredients (AI). The results suggest that toxicity tests conducte d with the technical material will provide adequate information for es timating toxicological hazard of formulations to aquatic organisms. A preliminary hazard assessment performed by using the toxicity of the t echnical grade material divided by a species and formulation related f actor of extrapolation uncertainty would allow a hazard assessment for the formulation with a high degree of reliability. Based on the prese nted data, this factor could be as low as 5 for green algae, 10 for wa ter fleas, and 5 for fish without an unreasonable risk (2% or less) of substantially increased, environmentally relevant formulation toxicit y. Such an approach would save considerable numbers of test animals an d also allow improvement of formulations without unnecessary or even e conomically prohibitive replications of numerous tests.