US EPA releases atrazine meeting minutes and final report

Date:11-20-2023

The U.S. Environmental Protection Agency (EPA) is releasing the meeting minutes and final report document for the August 2023, Federal Insecticide, Fungicide and Rodenticide Act Scientific Advisory Panel (FIFRA SAP) that peer reviewed EPA’s white paper: Examination of Microcosm/Mesocosm Studies for Evaluating the Effects of Atrazine on Aquatic Plant Communities. The white paper presented EPA’s reevaluation of 11 atrazine studies identified by the 2012 FIFRA SAP as warranting further review.

Atrazine is one of the most widely used herbicides in the United States. It is used to control annual broadleaf and grass weeds in a variety of agricultural crops, primarily corn, sorghum, and sugarcane. Additionally, atrazine products are registered for a wide variety of uses including wheat, macadamia nuts, guava, soybeans, fallow crop lands, and non-agricultural use sites (e.g., turfgrass).

EPA's oversight of atrazine is required to include periodic re-evaluation through the registration review process to ensure that risk assessments and pesticide decisions reflect the best available science. As part of EPA’s ecological risk assessment of atrazine, the Agency reevaluated 11 studies used to determine the level of atrazine that poses a concern in aquatic environments when it gets into streams and watersheds as a result of being used on crops.

Atrazine has been subject to scientific integrity issues and litigation in the past, when the previous Administration directed career managers to exclude studies related to the effects of atrazine from being used as a basis for ecological risk management. The career managers refused to carry out the direction, and instead, in September 2020, EPA set a less protective regulatory limit for atrazine that was based on a policy decision rather than a scientific one. The following month, EPA received a petition alleging that the agency violated its duties under FIFRA by making its Atrazine Interim Registration Review Decision (pdf) (1.05 MB) without substantial supporting evidence. In August 2021, EPA sought a voluntary partial remand in light of President Biden’s executive order on protecting public health and the environment and restoring a commitment to science and scientific integrity. On December 14, 2021, the Ninth Circuit Court of Appeals granted EPA a voluntary partial remand, which provided the agency the opportunity to reevaluate it.

Based on its review of the substantial evidence associated with the atrazine ecological risk assessment and a consideration of growers’ need for flexible and manageable mitigation measures, on October 7, 2022, EPA issued for public comment proposed revisions to the Atrazine Interim Decision that included additional ecological risk measures. Additionally, EPA convened the FIFRA SAP on atrazine on August 2023 to examine studies used for the Ecological Risk Assessment of atrazine. EPA is planning to finalize the proposed revisions to the Atrazine Interim Decision in fiscal year 2024, after its review of the meeting minutes and report released today.

For additional information, please contact the Designated Federal Official, Tamue Gibson, at gibson.tamue@epa.gov or 202-564-7642.To see the meeting minutes and final report document, visit docket EPA-HQ-OPP-2023-0154 at www.regulations.gov.

Relevant news

EPA Posts for Public Comment Examination of Microcosm/Mesocosm Studies for Evaluating the Effects of Atrazine on Aquatic Plant Communities

Peer Review of the Examination of Microcosm/Mesocosm Studies for Evaluating the Effects of Atrazine on Aquatic Plant Communitie