On August 18, 2021, the U.S. Environmental Protection Agency (EPA) announced that it will stop the use of the pesticide chlorpyrifos on all food. In the pre-publication of the Federal Register notice released on August 19, 2021, EPA revoked all “tolerances” for chlorpyrifos, which establish an amount of a pesticide that is allowed on food. In addition, EPA states that it will issue a Notice of Intent to Cancel under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) to cancel registered food uses of chlorpyrifos associated with the revoked tolerances. EPA has stated the cancellation order will follow in approximately six months after the tolerance revocations.

EPA’s announcement responds to the Ninth Circuit’s order, issued on April 29, 2021, that vacated EPA orders issued in 2017 and 2019 denying a 2007 petition filed by Pesticide Action Network North America and Natural Resources Defense Council. That petition requested that EPA revoke all chlorpyrifos tolerances, or the maximum allowed residue levels in food, because those tolerances were not safe, in part due to the potential for neurodevelopmental effects in children. The 2017 and 2019 orders denying the 2007 petition were challenged in the Ninth Circuit by a coalition of farmworker, health, environmental, and other groups.

In its order, the Ninth Circuit found that “...EPA had abdicated its statutory duty under the Federal Food, Drug and Cosmetic Act (FFDCA) ...” to “conclude, to the statutorily required standard of reasonable certainty, that the present tolerances caused no harm.” After vacating the 2017 and 2019 orders, the court remanded the matter to EPA with instructions to: “(1) grant the 2007 Petition; (2) issue a final regulation within 60 days following issuance of the mandate that either (a) revokes all chlorpyrifos tolerances or (b) modifies chlorpyrifos tolerances and simultaneously certifies that, with the tolerances so modified, the EPA ‘has determined that there is a reasonable certainty that no harm will result from aggregate exposure to the pesticide chemical residue, including all anticipated dietary exposures and all other exposures for which there is reliable information,’ including for ‘infants and children’; and (3) modify or cancel related FIFRA registrations for food use in a timely fashion consistent with the requirements of 21 U.S.C. § 346a(a)(1).”

In its announcement, EPA states that it has determined that the current aggregate exposures from the 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. Chlorpyrifos is an organophosphate insecticide used for a large variety of agricultural uses and has been continually reviewed with regard to potential adverse effects, including possible neurological effects in children, which has been the subject of considerable controversy for many years. EPA’s announcement notes that a number of other countries, including the European Union and Canada, and some states, including California, Hawaii, New York, Maryland, and Oregon, have taken similar action to restrict the use of this pesticide on food.

EPA states its action also will 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 www.regulations.gov and a discussion of these issues is available here.

After considering public comments, EPA will proceed with its registration review of the remaining non-food uses of chlorpyrifos by issuing the interim decision, which may consider additional measures to reduce human health and ecological risks.

Commentary

Separate from any issues of science, evidence, or interpretation, the FFDCA’s channels of trade provision is designed to address what happens if EPA cancels a pesticide product for not meeting Food Quality Protection Act (FQPA) standards and then revokes the tolerance. EPA’s initial description of its decision was unclear on this important point regarding the status of food already in the channels of trade that may contain chlorpyrifos residues.

EPA statements at an August 18, 2021, phone briefing with agricultural stakeholders appeared to present a position that the tolerance revocations would be in effect immediately upon publication in the Federal Register. This implied that there may be an immediate revocation of the tolerances before any parallel action to cancel the associated pesticide registrations. The pre-publication version of the notice clarified that the revocation of chlorpyrifos tolerances would not become effective until six months after the publication of the notice in the Federal Register.  As of August 24, 2021, the notice has not been published in the Federal Register.

This revocation delay of six months aligns with the statement also made by EPA to cancel the registration of chlorpyrifos food use products six months after the revocation notice. EPA may face questions from some of the groups that have been advocating for this type of EPA action concerning why, if these tolerances need to be revoked, the use of the pesticide will continue in effect for the remainder of this growing season. Ed Messina, Office Director of the Office of Pesticide Programs, made a glancing reference to this at the phone conference when he stated EPA and the U.S. Food and Drug Administration (FDA) are “having discussions.” 

According to EPA, use of chlorpyrifos has been in decline due to restrictions at the state level and reduced production. EPA also notes that some alternatives have been registered in recent years for most crops, other chemistries and insect growth regulators are available for certain target pests, and that EPA is committed to reviewing replacements for and alternatives to chlorpyrifos. Some growers, however, are using registered chlorpyrifos products on food crops and hoped to be able to continue certain uses. 

EPA states in the pre-publication notice that some uses in certain areas appear to be able to meet the FQPA standard as evaluated in its 2016 and 2020 risk assessment documents, even if including the full 10x FQPA “extra” safety factor (these assessments are the reference documents EPA cites in its revocation notice). EPA further states that the Ninth Circuit’s order did not provide EPA with time to consider further changes to the use patterns or label restrictions to align with such changes hinted at in the revocation notice, and so EPA is issuing the revocation decision now. This begs the question of whether EPA might consider some continued uses in the future, although even considering any “new” tolerance would be very controversial.

In addition, none of the current actions affect (for now) the tolerances for stored grains using the sister chemical (chlorpyrifos-methyl) with a similar toxicological profile. There also are non-food use applications of chlorpyrifos, for example, mosquito control application of chlorpyrifos sprayed over a large area, that are not affected by the tolerance revocation.

This mix of messages may not be easy to explain to users and the consuming public. 

Issues regarding the timing of the revocations and continued uses are also likely to present challenges for FDA. For example, there are various blended commodities (e.g., animal feed grain, possibly co-mingling harvests from different times) where FDA may be unable to determine what part of any enforcement sample came from a particular date of use.

The orderly transition for treated commodities was designed to avoid public and grower confusion that characterized the episodes of StarLink corn chaos in 2000 or the Cheerios contamination incident in 1994 involving a reported over 100 million boxes of cereal that were eventually destroyed. EPA cites international trade obligations as another reason for the coordinated actions effective in six months to notify foreign trading partners with a “reasonable interval” for adjusting to a changed regulatory situation.