On December 26, 2023, comments will be closing on a U.S. Environmental Protection Agency (EPA) proposed strategy to better screen pesticides and agricultural chemicals for harm to the human endocrine system. During this comment period, the manufacturers of select high-priority agricultural chemicals are also being asked to submit additional endocrine data for review. Some stakeholders—such as Bayer, the producer of controversial herbicide RoundUp—are asking for an extension to the data submission deadline.

The proposed EPA strategy is intended to ensure that its assessments of pesticides more closely, quickly, and effectively evaluate the potential for endocrine effects in humans, thereby enhancing EPA’s protection of public health by enabling the agency to make better informed decisions under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).

The strategic plan describes how EPA will carry out its endocrine Disruptor Screening Program (EDSP) in the near and long-term—a program that, according to EPA, “received minimal support and direction from leadership in the last administration.” Because of this and other issues—such as historically lacking scientific capacities to rapidly and cost-effectively test thousands of chemicals for endocrine-disrupting effects, and EPA’s past FIFRA decisions rarely explaining whether or how the agency obtained sufficient endocrine data to protect public health—the U.S. Office of the Inspector General issued a report in 2021 concluding that EPA had made limited progress in implementing EDSP and recommended that agency develop an EDSP strategic plan.  

EDSP was established in 1996 following an amendment to the Federal Food, Drug, and Cosmetic Act (FFDCA) to evaluate how pesticides and other chemicals may affect estrogen, androgen, and thyroid systems. The strategic plan proposed by EPA is designed to advance EDSP in several ways.

First, EPA intends to use its existing FIFRA data collection authorities to obtain the data it needs to make both FIFRA and EDSP decisions on whether pesticides impact the human estrogen, androgen, and thyroid systems, and will require any needed protections. Given the large number of pesticides awaiting these decisions, EPA is prioritizing the approximately 400 conventional pesticide active ingredients that are being registered for the first time or undergoing registration review.  

EPA also plans to make endocrine decisions related to human health more expeditiously by using existing data when possible. The agency routinely obtains data under FIFRA that are identical or comparable to data that EPA would have obtained through EDSP. Additionally, other existing studies may inform EDSP findings. Where data are sufficient to support EDSP findings under FFDCA, EPA intends to make such findings without seeking additional data, thereby minimizing duplicative and expensive animal testing and expediting EPA’s ability to make decisions without waiting for new studies. To support the strategic plan, EPA has released a scientific paper that addresses longstanding questions about which types of existing data can inform endocrine findings under FIFRA and FFDCA.  

After evaluating available data for 403 conventional pesticides, EPA determined it has adequate estrogen and androgen data for 86 of the chemicals. Therefore, as part of registration review, after assessing for potential thyroid effects, EPA can make final EDSP decisions on the potential for these chemicals to impact the human estrogen, androgen, and thyroid systems. Similarly, EPA has determined it has sufficient data for 52 pesticide chemicals (50 conventional active ingredients and two inert ingredients) it prioritized in 2009 to assess the potential for these chemicals to impact the human estrogen, androgen, and thyroid systems. As a supplement to the strategic plan, EPA has also communicated its final EDSP decisions relating to impacts on the human estrogen, androgen, and thyroid pathways for these 52 chemicals.  

Because the science on the human endocrine system evolves constantly, especially for the thyroid, EPA anticipates seeking in 2025 scientific peer review on scientific advancements and on its current approach to thyroid assessments, at which time the agency will determine whether to update its approach.  

Finally, in the near-term, EPA intends to require additional endocrine data for human health for 30 high-priority pesticides due to preliminary data indicating the chemicals may cause activity in the endocrine system. EPA sought available data or information on the chemicals for 60 days as part of a public comment period, which is coming to a close on December 26, and for which companies like Bayer are requesting an extension.

Additionally, to fill any remaining data gaps, EPA intends to issue FIFRA human health data requests for the high-priority chemicals in the spring of 2024. EPA is also seeking available data or other information to evaluate endocrine data needs for a second group of 126 conventional pesticides for which the agency’s initial analysis has found limited endocrine data. For 161 additional conventional pesticides, EPA will determine which ones it needs to obtain updated endocrine data for in the coming years as part of its registration review.