An appeals court has overturned the federal registration for dicamba herbicides sprayed on biotech soybeans and cotton, but the ruling may have broader implications for pesticide regulation.

Dicamba formulations used on genetically engineered crops were approved by the U.S. Environmental Protection Agency in violation of federal pesticide law, according to the 9th U.S. Circuit Court of Appeals.

Specifically, the 9th Circuit said the EPA “substantially understated risks” and “failed entirely to acknowledge other risks” in reviewing these new over-the-top uses of dicamba, such as adverse economic and social impacts from the herbicide damaging non-resistant plants.

The ruling will set an “important precedent” for other pesticides undergoing EPA registration or re-registration, especially those applied on crops genetically modified to withstand the chemicals, said George Kimbrell, legal director of the Center for Food Safety, a nonprofit that filed a lawsuit over the dicamba formulations.

“Those are important points of law that are now the law of the land,” Kimbrell said.

The 9th Circuit’s opinion faults the agency for miscalculating the true costs of over-the-top dicamba applications, which should heighten the scrutiny applied to other pesticides under EPA review, Kimbrell said.

Under the ruling, the spraying conditions imposed on pesticides cannot be impossible to follow in the “real world,” which was a major shortcoming in EPA’s analysis of the dicamba products, he said.

Allowing a chemical to be sprayed only when there’s a “unicorn in the field” is unrealistic, as are the extremely narrow wind speed conditions and other restrictions required for the dicamba formulations, he said.

“They just slap them on the label and assume they can be followed,” Kimbrell said.

The legal principles invoked in the 9th Circuit’s ruling apply “across the board” in the EPA’s analysis of pesticides, including new formulations used in “cropping systems” developed by biotech companies, he said.

“This is their model of industrial agriculture,” Kimbrell said.

Croplife America, a group representing the pesticide industry, believes the 9th Circuit’s ruling is “wrong on many fronts” and should be challenged by the EPA, said Chris Novak, the association’s CEO.

The 9th Circuit has substituted its judgment for the expertise of the agency in analyzing the herbicide’s risks and has established an “impossible standard to meet” by requiring EPA to “anticipate all illegal uses,” Novak said.

While cotton and soybeans aren’t commonly grown in the Pacific Northwest, the region does produce sugar beets that have been genetically modified to withstand glyphosate herbicides. A sugar beet cultivar that would tolerate dicamba is also in development.

Dicamba is a controversial herbicide, and the ruling could have adverse consequences for similar cropping systems, said Allison Crittenden, director of congressional relations with the American Farm Bureau Federation.

“It could limit access to that technology,” Crittenden said.

The 9th Circuit’s consideration of social consequences in farming communities is unique and could be cited by plaintiffs suing over other pesticide formulations, said Brigit Rollins, staff attorney with the National Agricultural Law Center at the University of Arkansas.

“Is that a box the EPA will need to be checking, and if so, to what degree?” she said. “It does seem likely they’ll take that into consideration going forward.”

The environmental plaintiffs likely filed their lawsuit in the 9th Circuit expecting the appellate court would be sympathetic to their cause, said Mary Boote, CEO of the Global Farmer Network, which advocates for technology in agriculture.

“Could a precedent be set? I’m not going to argue with that, because that’s what they’re trying to do,” she said.

Growers should be troubled by the decision even if they don’t rely on dicamba-resistant soybeans or corn, Boote said.

“If they can do it here, what is the next one they’re going to go after?” she said. “Today dicamba, tomorrow what if it’s something you’re using?”

The 9th Circuit criticized the EPA’s analysis of the dicamba formulations for minimizing the amount of dicamba applied by farmers and the number of complaints about the herbicide drifting onto neighboring properties.

The agency also didn’t take into account that farmers weren’t complying with label requirements for the dicamba products, whose difficulty had “dismayed” even industry professionals, the ruling said.

Damage from dicamba drift has also “torn apart the social fabric of many farming communities,” with disputes breaking out among neighbors and one argument even leading to a shooting death, the 9th Circuit said.

As for the economic cost of the formulations, the EPA “entirely failed to acknowledge” such problems as farmers feeling compelled to plant resistant crops to avoid damage from drifting dicamba, the 9th Circuit said.

“The likely anti-competitive effect of the registrations would impose a clear economic cost, but the EPA at no point identified or took into account this cost,” the ruling said.