Ruling casts doubt on insecticide’s future availability

Issue Date: August 15, 2018
By Ching Lee

The manufacturer of the insecticide chlorpyrifos said a court order to ban the material does not require immediate change to uses of the pesticide, and that it expects the U.S. Environmental Protection Agency to challenge the ruling.

In a 2-to-1 decision last week, the 9th U.S. Circuit Court of Appeals gave the EPA 60 days to cancel the registration and all food-residue tolerances for the broad-spectrum pesticide, which has been used to protect a wide range of California-grown crops, including almonds, alfalfa, citrus fruit, walnuts, cotton, vegetables and others.

The ruling vacates an order by the EPA last year to deny a petition from environmental groups and farmworker advocates to ban the material, prompting the lawsuit. The groups have been urging a ban since 2007, when they first petitioned the agency.

The 2017 EPA order reversed plans proposed by the Obama administration in 2015 to cancel tolerances for chlorpyrifos, an organophosphate first approved for use in 1965 and sold commercially as Lorsban, Warhawk, Vulcan and other brand names. The agency said it would "continue to review the science addressing neurodevelopmental effects" and complete its assessment by October 2022.

In its decision, the court said it could find "no justification for the EPA's decision in its 2017 order to maintain a tolerance for chlorpyrifos in the face of scientific evidence that its residue on food causes neurodevelopmental damage to children."

EPA has not said what it plans to do. It could appeal the decision or comply with the court ruling and cancel registration for chlorpyrifos.

Corteva Agriscience, a division of DowDupont, which manufactures chlorpyrifos, said in a statement that "all approved uses and tolerances remain intact until the U.S. EPA makes a final decision." Noting the court's split decision, the company said it expects "all appellate options to challenge the majority's decision will be considered."

If the ruling stands and chlorpyrifos is banned, "we expect significant impacts to food and fiber production," said Jim Houston, California Farm Bureau Federation manager of governmental and legal affairs.

As a pest control advisor, Justin Nay of Integral Ag in Butte County said losing chlorpyrifos would force pest managers to rely more on what few products remain to fight certain pests, and more frequent usage could render those materials less effective over time.

"You take away Lorsban, we really only have pyrethroids left as our main knock-down product, which is going to shorten its lifespan in the field," he said.

Because chlorpyrifos use already faces significant restrictions, Nay said many farmers have cut usage. He said he now uses it primarily to fight codling moth in walnuts, and leaffooted bug and navel orangeworm in almonds.

"I feel like we've already done a good job of not using it wastefully," Nay said. "That being said, when you need it, you need it."

Norm Groot, executive director of the Monterey County Farm Bureau, said the Central Coast "has drastically reduced the use" of chlorpyrifos as part of an agricultural water-quality program.

"It is one of the tools in the toolbox that keeps getting smaller with bad decisions like this one," he said of the court ruling.

Though he doesn't use chlorpyrifos every year, Merced County farmer Cannon Michael said for certain crops and certain pests such as the cotton aphid, "there's really not anything out there that's really effective." Losing the material, he said, would lead to "a big economic loss" if farmers don't have a way to control these pests.

"We just have a much more limited suite of products, so anything that comes off the table is a big potential loss for us," he said.

Michael said "a lot of scientific evidence" shows chlorpyrifos can be used safely, and California farmers were "instrumental in working with regulators" on a plan that offers "a lot of protections" while allowing farmers to continue using the product. Having a complete ban, he said, would "put us in an impossible situation."

"We're very conscious of how things are applied, when they're applied, making sure the worker is protected," he said. "We take very seriously our responsibility to not do things that endanger our workers—and endanger the consumer."

Greg Meyers, who grows tree crops in Fresno County, said he uses chlorpyrifos against navel orangeworm in his almonds and pistachios, but said he has "generally moved away from it" because of the many regulatory hurdles.

"It requires different equipment to mix and load," he said. "If you're applying it by ground, your cab has to be airtight. It has to have an EPA-approved air filtration system. You're not allowed to go into the field unless you have protective clothing—coveralls, gloves, rubber boots, respirator, all that stuff."

But he said it remains an important tool to have for times such as last year, when infestations of navel orangeworm were "horrendous" and damage to almond crops was "off the charts."

Tulare County citrus grower Chris Lange described chlorpyrifos as "a very effective tool," particularly for soft-scale insects. He said he would hate to lose it, but would transition to other materials.

"We have other options," he said. "They might not be as effective and they might not be as cheap, but I think we've just got to bite the bullet and transition to something else."

Stuart Woolf, a diversified grower in Fresno County with almonds, pistachios and other crops, said chlorpyrifos can take on many pests, including aphids and twig borer, while "other products that remain are less effective." But he said he's starting to use more bio- based products.

"You've got to try everything you can," he said.

(Ching Lee is an assistant editor of Ag Alert. She may be contacted at

Permission for use is granted, however, credit must be made to the California Farm Bureau Federation when reprinting this item.

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