In an action brought by twenty trade agricultural associations and one registrant, the 8^th Circuit on November 7, 2023[1]ordered EPA to revisit its August 30, 2021[2] revocation of all chlorpyrifos tolerances, which thereby eliminated all food uses.

            Chlorpyrifos, once the most used insecticide in the U.S., has been the subject regulatory concerns for decades. It is a cholinesterase inhibitor, exposure to which can cause neurological harm. In 1997 EPA reached an agreement with the major chlorpyrifos registrants to reduce residential applications and exposure. Controversy continued about the extent of the risks presented by the product. The next major event was a petition seeking revocation of all food use tolerances filed by the Natural Resources Defense Council (“NRDC”) and Pesticide Action Network North America (“PANNA”) in 2007. Without a tolerance, which determines the residue level of an ingredient that is allowed in a food product, a product may not be applied to food crops.

            After years passed without a decision, NRDC and PANNA brought a mandamus action in the 9^th Circuit Court of Appeals seeking to compel EPA to issue a decision. In 2015 the Court issued a mandamus order requiring EPA to issue a decision on the petition and proposed tolerance revocations[3]. In April, 2017, EPA denied the petition and declined to revoke any tolerances[4]. Following an appeal of that order, EPA confirmed its position in 2019.[5]

            In 2020 EPA issued the Chlorpyrifos Proposed Interim Reregistration Review Decision. It found that chlorpyrifos did pose risks from certain uses and proposed to revoke certain tolerances.  After reviewing objections from various parties, EPA confirmed its decision.[6] That decision was challenged, and the 9^th Circuit Court ordered EPA to revisit the remaining tolerances.[7] EPA was given sixty days to either determine those uses that could be safely continued with appropriate tolerances or revoke all tolerances. EPA determined that it was not feasible in that timeframe to assess what uses could be safely continued and revoked all tolerances. The Red River Valley Sugarbeet Growers Association action was brought in response.

            The 8^th Circuit Court found that EPA’s decision to not retain specific tolerances which data suggested did not present unacceptable risks was arbitrary. The Court was not impressed by EPA’s determination that it did not have time to consider what tolerances to retain. It held that the short deadline imposed by the 9^th Circuit in League of Latin American Citizens v. Regan did not justify omitting any consideration of such acceptable uses which the law required EPA to do. The Court essentially said that EPA should have worked harder and faster.

            The Court has returned the issue to EPA to reconsider the entirety of its prior revocation order. EPA documents do suggest that if it had more time previously it would have considered retaining some tolerances, so such an action might well be taken. If so it would remain to be seen how the market accommodates the restoration of such uses. The tolerance revocation did not revoke or suspend the registration of chlorpyrifos products, but it would remain to be seen how the market would respond to the restoration of any uses. It is interesting to observe that the only registrant to join the 8^th Circuit action was Gharda, a generic registrant from India.   

            Reacting to the decision on February 2, 2024 EPA issued a Federal Register notice[8] reinstating the tolerances as directed by the Court. On March 15, 2024, EPA issued a product-specific notice regarding existing stocks, specifying the time periods in which products can continue to be used by growers.

            Chlorpyrifos remains under intensive review.  EPA is likely again to revoke numerous tolerances, while the product continues to undergo Registration Review.  Its future remains cloudy at best.

[1]Red River Valley Sugarbeet Growers Association et al v. Regan (8^th Cir. 2023 [No. 22-1422]).

[2] 86 Fed. Reg. 48315 (August 30, 2021).

[3] In Re Pesticide Action Network N. Am., 798 F.3d 809 (9^th Cir. 2015).

[4] 82 Fed. Reg. 16585 (April 5, 2017).

[5] 84 Fed. Reg. 35555 (July 24, 2019).

[6] 87 Fed. Reg. 112222 (Feb. 28, 2022).

[7] League of Latin American Citizens v. Regan, 996 F. 3d 673 (9^th Cir. 2021.)

[8] 89 Fed. Reg. 7625 (February 5, 2024.)