The Environmental Protection Agency announced Wednesday its proposed decision to reregister dicamba, a herbicide widely used on soybean and cotton farms that has been banned twice by federal courts. The EPA originally approved dicamba’s use on genetically engineered soybeans and cotton in 2016. Environmental groups sued the EPA over dicamba in 2020 because of its potential drift away from the intended target, especially during warmer temperatures, and harm neighboring crops, nearby ecosystems and rural communities.

The U.S. Court of Appeals for the 9th Circuit ruled against the EPA and said the agency “understated the amount of dicamba damage.” The court determined that dicamba “caused substantial and undisputed damage” that tore the “social fabric of the farming communities.”

After the court vacated the herbicide’s registration, the EPA re-registered it months later, and was again challenged by environmental groups. A second federal court vacated that registration in 2024 and prohibited the sale of the herbicide.

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In its new proposal, the EPA said it would address risks from dicamba’s volatility by requiring temperature cut offs above 95 degrees and the increased use of drift reduction agents when temperatures are above 75 degrees. It also includes plans to address the risk of runoff.

The proposed mitigations will “minimize impact to certain species and the environment,” said EPA spokesperson Molly Vaseliou in a statement.

Agriculture groups applauded the EPA’s proposal.

The American Soybean Association, a trade association, said in a statement that dicamba is a critical tool for soybean farmers.

“While ASA is still reviewing the details of EPA’s long-anticipated proposed re-registration decision, we recognize the agency has conducted a robust scientific assessment to evaluate and address potential risks associated with over-the-top dicamba use,” the statement said.

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The proposed registration includes products containing dicamba made by Bayer, Syngenta, and BASF.

“This technology provides tremendous value to soybean and cotton farmers across the U.S.,” said Bayer in a statement. “Helping growers safely and successfully raise healthy crops is what we do, and we are confident that low-volatility dicamba herbicides, when used according to the label, can be used safely and successfully on-target.”

BASF said in statement that the company is committed to working with officials and stakeholders to ensure that “uses of dicamba remain an option for farmers in the future.”

Syngenta did not immediately respond to a request for comment.

Bill Freese, the science director at Center for Food Safety, a sustainable agriculture advocacy group who spearheaded the lawsuits against EPA, said all of the previous steps taken by the EPA to prevent dicamba from drifting onto neighboring properties had failed.

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The proposed regulation, Freese said, “loosens the already inadequate restrictions,” by removing limitations on when the herbicide can be used.

“We warned EPA from the very beginning that this crop system would be very hazardous,” Freese added.

Robert Hartzler, an emeritus professor of weed science at Iowa State University, said it’s essentially impossible to contain dicamba where it’s sprayed.

“Even if the applicator takes the utmost care and is applying it correctly, it gets up from where it landed and moves out of the treated field,” he said.

The popularity of dicamba, which was first introduced in 1967, arose from a need to find solutions to Roundup-resistant weeds, also known as “superweeds.” Monsanto, which made Roundup before the company was acquired by Bayer, began selling genetically engineered seeds that could survive being doused by dicamba and Roundup in 2016.

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Between 2016 and 2019, dicamba use across the country nearly quadrupled to an estimated 31 million pounds a year, according to estimates from the U.S. Geological Survey.

The proposal to reregister dicamba comes less than a month after Kyle Kunkler, a former lobbyist for the American Soybean Association, was named the deputy assistant administrator for pesticides in EPA’s Office of Chemical Safety and Pollution Prevention.

Asked for comment on whether Kunkler’s appointment influenced the agency’s dicamba decision, Vaseliou said the “EPA follows the federal Insecticide, Fungicide, and Rodenticide Act when registering pesticides” and that any insinuation otherwise was “further ‘journalism’ malpractice by The Washington Post.”

Nathan Donley, a senior scientist at the Center for Biological Diversity, an advocacy group that sued the EPA over the herbicide, said environmentalists won’t shy away from challenging the agency in court.