Sunday, September 19, 2021

EPA revokes chlorpyrifos tolerances, plans to cancel food uses

corn rootworm larva
This is a picture of the southern corn rootworm. It is one of a handful of soilborne pests controlled by chlorpyrifos.

The U.S. Environmental Protection Agency has revoked all tolerances for chlorpyrifos and plans to issue a notice of intent to cancel registered food uses of the insecticide associated with the revoked tolerances.

The final rule announcing the revocations becomes effective 60 days after the EPA’s final notice is published in the Federal Register. And the revocations become effective for all commodities six months from publication.

In a statement, the agency said it was taking the action to “better protect human health, particularly that of children and farmworkers.”

Adama’s perspective

One of the product registrants, Adama, still stands behind the science involved in registering the insecticide. But the company decided to cease supplying its chlorpyrifos products (Vulcan Insecticide and Chlorpyrifos 4E) for agricultural uses.

The move — a strategic business decision — will allow it to focus on other newer products.

“Although Vulcan provided highly effective control of aphids, borers and worms, its popularity has waned in recent years,” Jake Brodsgaard, Adama vice president, U.S., said in a statement. “The void is being filled by other chemistries, such as Silencer VXN, Fanfare ES, Diazinon AG500, Diamond, Cormoran and Fulfill.”

Corteva, which had marketed chlorpyrifos under the Lorsban brand, decided to phase out production globally in 2020 due to declining demand.

What is chlorpyrifos?

Chlorpyrifos is an organophosphate insecticide used for a large variety of agricultural uses, including soybeans, fruit and nut trees, broccoli, cauliflower, and other row crops, as well as non-food uses. In peanuts, it is used to control several economically important soilborne pests, including peanut burrower bug, southern corn rootworm, wireworms and lesser cornstalk borer.

Chlorpyrifos has been found to inhibit an enzyme, which leads to neurotoxicity. It also has also been associated with potential neurological effects in children.

The steps announced are based on the Ninth Circuit Courts’ order directing EPA to issue a final rule in response to the 2007 petition filed by Pesticide Action Network North America and Natural Resources Defense Council. The petition requested that EPA revoke all chlorpyrifos tolerances, or the maximum allowed residue levels in food, because those tolerances were not safe.

History of legal actions

Under the previous administration, EPA denied the petition in 2017 and denied the subsequent objections in 2019. These denials were challenged in the Ninth Circuit Court of Appeals in 2019 by a coalition of farmworker, health, environmental and other groups.

In April, the court found that “…EPA had abdicated its statutory duty under the Federal Food, Drug and Cosmetic Act…” to “conclude, to the statutorily required standard of reasonable certainty, that the present tolerances caused no harm.”

In its decision, the court ordered EPA to grant the petition, issue a final rule in which the agency either modified chlorpyrifos tolerances with a supporting safety determination or revoked the tolerances, and modify or cancel food-use registrations of chlorpyrifos.

EPA has determined that the current aggregate exposures from use of chlorpyrifos do not meet the legally required safety standard that there is a reasonable certainty that no harm will result from such exposures.

A number of other countries, including the European Union and Canada, have taken similar action to restrict the use of this pesticide on food. Several states, including California, Hawaii, New York, Maryland and Oregon, have also done so.

The next steps

This action will also be incorporated into the ongoing registration review for chlorpyrifos. EPA is continuing to review the comments submitted on the chlorpyrifos proposed interim decision, draft revised human health risk assessment and draft ecological risk assessment. These documents are available in the chlorpyrifos registration review docket EPA-HQ-OPP-2008-0850 at

After considering public comments, the agency will proceed with registration review for the remaining non-food uses of chlorpyrifos by issuing the interim decision, which may consider additional measures to reduce human health and ecological risks. More information on the registration review process is available here.

More information about chlorpyrifos and the final tolerance rule is available on EPA’s website.

The Environmental Protection Agency provided information for this article.

Related Articles

E-News Sign-Up

Quick Links