EPA Opens Public Comment on Dicamba Use Proposal

By Andi Anderson

The U.S. Environmental Protection Agency (EPA) is inviting public feedback on proposed registrations for three new dicamba herbicide products. These are intended for postemergence use in dicamba-tolerant cotton and soybean crops. The proposal includes updated guidelines to limit health and ecological risks while improving weed control.

Dicamba helps control broadleaf weeds, especially those resistant to other herbicides. However, improper use has raised concerns about environmental drift and non-target plant damage. EPA’s new registration proposal includes strict mitigation measures to reduce these impacts.

Key restrictions include a maximum single-use application rate of 0.5 lb. per acre and no more than two applications per year. Aerial applications are prohibited, and a 240-foot downwind buffer must be maintained. Farmers must also use drift reduction agents and pH buffers in the spray mix, especially as temperatures rise.

Applications are banned when forecast temperatures exceed 95°F. If temperatures are above 85°F, only 60% of a field may be treated unless no tank mixes are used. A second pass can be made two days later for untreated areas.

EPA’s review found no major human health risks. Risks to fish, aquatic species, and bees are low. To protect endangered species, applicators must follow bulletins from the "Bulletins Live! Two" system and meet additional runoff and erosion control points in sensitive areas.

Applicators must wear personal protective equipment, including gloves and respirators for certain formulations, and complete dicamba-specific training. The product use will be limited to certain states and to certified applicators only.

The public can view and comment on the proposal via Docket ID EPA-HQ-OPP-2024-0154 at www.regulations.gov. The comment period closes on August 22, 2025.

EPA will finalize its decision after reviewing all comments and consulting with the U.S. Fish and Wildlife Service if needed to address impacts on endangered species.

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