The U.S. Environmental Protection Agency (EPA) OPPTS 850.1350 Mysid Chronic Toxicity Test (draft, 1996) is conditionally required (40 CFR Part 158.630) for the registration of pesticide products in the U.S. Although this study is not required by regulatory agencies outside of North America, results have an impact on product registrations across the globe if the endpoint drives the risk assessment.
The primary challenges with successful completion of this study are due to a lack of detailed information within the EPA test guideline (TG) on the study design and conduct. Issues with test organism performance often result in studies that do not meet acceptability criteria, necessitating a study repeat.
CropLife America (CLA) has previously identified issues concerning the language in the existing TG, including: 1) Lack of clarity about study endpoints; 2) Limited guidance for handling the second generation (G2) populations; 3) Difficult to achieve data quality objectives for growth and reproduction; and 4) A need to update procedures to reflect methodological improvements following 20+ years of laboratory experience in performing this study. A joint CLA-CLE (CropLife Europe) project was undertaken to review issues with study design and subsequently develop recommendations for the modernization of the TG.
Lee Sayers, Research Director, presented the research with poster co-authors at the SETAC North America 43rd
Annual Meeting, November 13-17, 2022.