On December 2, 2024, the U.S. Environmental Protection Agency (EPA) released, and is seeking public comment on, its proposed guidance for antimicrobial pesticide registrants intended to improve the efficiency of Endangered Species Act (ESA) considerations for new active ingredients, new uses, and registration review actions for antimicrobial pesticides. Comments are due on or before January 1, 2025.

EPA states that this guidance, when issued in final, will fulfill the requirements outlined in the Pesticide Registration Improvement Act of 2022 (PRIA 5) and further the goals outlined in EPA’s 2022 ESA Workplan to protect listed species from exposure to pesticides. EPA stresses that although this document does not create new requirements for applicants, the recommendations in the guidance will help applicants address potential effects to listed species and make EPA’s development of effects determinations more efficient for new active ingredients, new uses, or registration review decisions of products with one or more uses for antimicrobial pesticides that have the potential for outdoor exposures.

PRIA 5 specifies that the proposed guidance for antimicrobial pesticides will be available for public comment and will be issued in final within three years of PRIA 5’s issuance in December 2022 (i.e., December 2025). Among other requirements, PRIA 5 mandates that EPA develop and issue guidance to registrants regarding analyses necessary to support the evaluation of potential adverse effects from new outdoor uses of pesticide products on listed species and designated critical habitat. While PRIA 5 focuses on outdoor uses, this guidance addresses all antimicrobial pesticide uses, including indoor uses with the potential for exposures to listed species and designated critical habitat (e.g., antimicrobial pesticides used to treat water in industrial settings that are released directly into surface water). The guidance document focuses on the actions that applicants can voluntarily pursue prior to submitting an application that may determine the proposed mitigation measures to best protect the listed species. These actions include identifying where a pesticide will be used, how species may be exposed to the pesticide, and how to select mitigation to reduce the exposure.

Additional guidance was made available in 2023 for conventional and biopesticide new active ingredient applications or active ingredients undergoing registration review with one or more outdoor uses and new outdoor uses of existing conventional pesticides and biopesticides active ingredients, which were developed in response to the PRIA 5 requirement.

The proposed guidance is available for public comment at regulations.gov in docket EPA-HQ-OPP-2023-0281.

Commentary

It may come as a surprise that antimicrobial pesticides will need to include consideration of possible impacts on endangered species, but some exposures due to use of these products could lead to exposure in certain circumstances. This will be one of the first questions EPA will need to answer — is there potential exposure through water or other off-target movement (examples: through soil or aerial drift) that could lead to exposure to threatened or endangered species (TES). EPA has developed an extensive plan for finally addressing how to integrate the ESA with Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) requirements. Although antimicrobial products are less likely to present ESA issues, EPA will examine the broader strategy of what it refers to as “avoidance and minimization” of toxic exposures to TES, and may impose additional requirements compared to past reviews.