EPA Posts Final Endangered Species Act Biological Opinion for Enlist Herbicide Products
Released on December 1, 2023
The U.S. Environmental Protection Agency (EPA) posted the U.S. Fish and Wildlife Service’s (FWS) final biological opinion (BiOp) for Enlist pesticide products. Enlist One and Enlist Duo are two herbicides used to control weeds in corn, cotton, and soybean crops. These crops have been genetically modified to be resistant to these pesticide products
Under the Endangered Species Act (ESA), EPA must ensure that its actions, including pesticide registration actions, do not jeopardize federally threatened and endangered (listed) species, or adversely modify their designated critical habitats. If EPA determines in a biological evaluation (BE) that use of a pesticide product may affect listed species or critical habitats, the Agency must initiate consultation with FWS, the National Marine Fisheries Service, or both (the Services). In response, the Service(s) may develop a BiOp that determines whether the pesticide is likely to jeopardize listed species or adversely modify their critical habitats and propose measures to avoid jeopardy and adverse modification.
Background on Enlist Products
In January 2022, EPA completed a comprehensive ecological risk assessment for 2,4-D choline salt (2,4-D), an active ingredient in both Enlist products, and glyphosate dimethylammonium salt (glyphosate), an active ingredient in Enlist Duo. EPA also completed an effects determination in a BE for both Enlist products’ potential effects on listed species and critical habitats, including “likely to adversely affect” (LAA) determinations for multiple species and critical habitats. This LAA determination means that EPA reasonably expects that at least one individual animal or plant, among a variety of listed species, may be exposed to Enlist One or Enlist Duo at a sufficient level to have an adverse effect. EPA also refined its analysis to predict the potential likelihood that the use of these products could result in “jeopardy” (J) for any listed species or “adverse modification” (AM) of any critical habitats. In contrast to its LAA determinations, EPA’s predictions of the potential likelihood of J/AM examine the effects of both active ingredients to populations of a species, rather than to an individual.
EPA initiated consultation with FWS upon completion of the BE for Enlist products and prior to registering both products. During consultation with FWS, EPA updated its LAA determinations by incorporating additional data (e.g., life-history, species distribution, likelihood and magnitude of plant effects, and impacts of required runoff mitigations).
EPA registered both Enlist One and Enlist Duo in January 2022. To protect listed species and critical habitats, label restrictions that limited application methods were included to address potential exposure from run-off and spray drift. In addition, the Enlist labels also included mitigation measures in areas EPA thought FWS may conclude J/AM. These measures included “off-labeling” certain counties from the use of Enlist One and/or Enlist Duo, meaning the products’ use was limited or prohibited in these counties. With these measures in place, EPA expected the use of these products would not likely lead to J/AM conclusions by FWS. EPA also anticipated that the protective measures would reduce the potential for unintentional harm (i.e., “incidental take”) to individuals of these listed species and their critical habitats.
Biological Opinion
This final BiOp is the result of EPA’s consultation with FWS and its consideration of information received from EPA, the registrant of the products, states, and stakeholders – including grower groups, industry, and environmental organizations – during EPA’s public comment process. The BiOp contains findings from FWS that the use of Enlist products, as specified in the approved product labels, are not likely to jeopardize any listed species or adversely modify their critical habitats. It also concludes that off-labeling counties is not needed to prevent J/AM conclusions for species and critical habitats that were part of the January 2022 assessment, but that for some species and critical habitats in those counties, specific species and habitat mitigation measures are still needed to prevent J/AM. EPA has updated its BE to reflect the results this FWS’s BiOp. To ensure compliance with sections 9 and 4(d) of the ESA (which exempts incidental take of some listed species), EPA will:
- Report annually to FWS with ecological incident data collected and analyzed.
- Review and act on label changes within 18 months of the BiOp issuance.
- Maintain and evaluate data on Enlist products exposure to listed species and critical habitats.
- Provide training and education to pesticide users and applicators.
Next Steps
The issuance of the final BiOp is the last step in EPA’s formal consultation process with FWS. With its issuance, EPA will work with the registrant to implement the BiOp. The Agency intends to have label revisions approved in advance of the next growing season. Mitigation actions resulting from the BE and BiOp are specific to certain geographic areas and can be found on the Agency’s Bulletins Live! Two system.
The full Enlist BiOp can be accessed at docket ID EPA-HQ-OPP-2021-0957 at regulations.gov.