U.S. EPA withdraws Difenoconazole Interim Registration Review Decision

On June 13, 2022, Center for Food Safety (CFS) filed a petition for review of the Difenoconazole Interim Registration Review Decision (ID) in the U.S. Court of Appeals for the Ninth Circuit. This petition challenged EPA’s issuance of the ID and alleged that EPA violated the Endangered Species Act (ESA) by issuing the ID before completing effects determinations for federally listed species or designated habitats and, if necessary, initiating consultation with the Services. CFS also alleged that the issuance of the ID violated the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) because EPA failed to obtain certain relevant data before issuing the ID. On April 3, 2023, the parties filed a joint motion for voluntary remand so that EPA may withdraw the difenoconazole ID and reconsider the issues CFS raised in its petition. The court issued an order on April 21, 2023, and corresponding mandate on June 13, 2023, granting the parties’ joint motion. In light of the court’s order and corresponding mandate, this memorandum announces EPA’s withdrawal of the difenoconazole ID.

A copy of the difenoconazole ID, now withdrawn, is available in the difenoconazole registration review public docket (EPA-HQ-OPP-2015-0401) at https://www.regulations.gov.

Background

Issuance of the Difenoconazole Interim Registration Review Decision

Registration review is EPA’s periodic review of pesticide registrations to ensure that each pesticide registration continues to satisfy the FIFRA standard for registration, that is, that the pesticide can perform its intended function without unreasonable adverse effects on human health or the environment. Under FIFRA section 3(g), each pesticide is required to be reviewed every 15 years.

EPA regulations establish procedures for the registration review program required in FIFRA section 3(g). Under 40 C.F.R. § 155.56, EPA may issue, when it determines it to be appropriate, an interim registration review decision before completing a registration review. Among other things, the Interim Registration Review Decision may require new risk mitigation measures, impose interim risk mitigation measures, identify data or information required to complete the review, and include schedules for submitting the required data, conducting the new risk assessment, and completing the registration review. Procedures for issuing an Interim Registration Review Decision are set forth in § 155.58.

On April 28, 2022, EPA published a notice in the Federal Register (87 Fed. Reg. 25266) announcing the availability of the difenoconazole ID. EPA issued the ID pursuant to 40 C.F.R. §§ 155.56 and 155.58, explaining that it was doing so to ″(1) move forward with aspects of the registration review case that are complete and (2) implement interim risk mitigation.″ The ID finalized EPA’s draft risk assessments supporting registration review, the Difenoconazole Draft Human Health Risk Assessment for Registration Review and the Difenoconazole Draft Ecological Risk Assessment for Registration Review. The ID did not identify any human health risks of concern from exposure to difenoconazole but did identify potential ecological risks of concern. It also identified interim risk mitigation measures, in the form of label changes, including instructions for how treated seed should be incorporated into soil, instructions for labeling of treated seeds, spray drift advisories, water advisories environmental hazard statements and certain label consistency measures. It concluded that, under FIFRA, the benefits of difenoconazole outweigh the potential ecological risks when difenoconazole is used in accordance with labels.

The difenoconazole ID did not make findings under section 7 of the ESA. EPA explained that it would do so before completing registration review for difenoconazole, and that the ″The Agency’s final registration review decision for difenoconazole will be dependent upon the result of the Agency’s ESA assessment and any needed § 7 consultation with the Services.″

For further background on difenoconazole and its registration review history, see the end of this memorandum.

Endangered Species Act Assessment for Difenoconazole

ESA section 7(a)(2) requires that federal agencies ensure that the actions they authorize, fund, or carry out are not likely to jeopardize the continued existence of species listed as threatened or endangered under the ESA (listed species) or destroy or adversely modify their designated critical habitat. For pesticides in registration review, EPA’s responsibility includes evaluating potential effects to listed species and their designated critical habitat, often through a biological evaluation (BE). EPA has not yet determined whether difenoconazole ″may affect″ or ″is likely to adversely affect″ listed species or designated critical habitat and therefore, formal consultation with the Services has not been initiated. Therefore, no BE has been developed for difenoconazole as of this time.

Challenges to Difenoconazole Interim Registration Review Decision

On June 13, 2022, CFS filed a petition for review of the difenoconazole ID in the Ninth Circuit. See Center for Food Safety. v. EPA, No. 22-70118. This petition sought vacatur of the difenoconazole ID, challenged EPA’s analysis of the human health risks of difenoconazole, and alleged that EPA violated the ESA by issuing the ID before completing consultation with the Services.

On April 3, 2023, EPA and CFS filed a joint motion for voluntary remand in which the Agency committed to withdrawing its ID within 30 days of the court’s final order or mandate granting the motion. The parties sought remand so that EPA may reconsider aspects of the difenoconazole ID, specifically the need for additional studies related to the metabolites of difenoconazole. EPA also noted it would reconsider the difenoconazole ID in light of the June 17, 2022 court issued opinion regarding challenge to the glyphosate ID. See Natural Resource Defense Council v. EPA, 38 F.4^th 34 (9^th Cir. 2022).

Withdrawal

EPA is withdrawing the Difenoconazole Interim Registration Review Decision. Because the ID is an informal adjudication that EPA issued at its discretion, EPA may withdraw all or a portion of it without public comment. EPA believes the withdrawal is appropriate to focus agency efforts on completing the required final registration review decision for difenoconazole, including considering the issues the petitioner raised in its motion for vacatur.

Although the difenoconazole ID is now withdrawn, that does not automatically mean that EPA’s underlying scientific findings regarding difenoconazole are either incorrect or cannot be used as support for a future decision following reconsideration in accordance with the court’s decision.

Next Steps

With respect to the withdrawn ID, EPA intends to revisit its evaluation of the human health effects from exposure to difenoconazole, specifically the need for additional studies related to the metabolites of difenoconazole. EPA also intends to reconsider the difenoconazole ID in light of the June 17, 2022 court issued opinion regarding challenge to the glyphosate ID. See Natural Resource Defense Council v. EPA, 38 F.4^th 34 (9^th Cir. 2022).

EPA also intends to complete an ESA assessment and any necessary § 7 consultation with the Services before issuing a final registration review decision for difenoconazole.

Difenoconazole Background and Registration Review History

Difenoconazole is a fungicide that is registered for foliar applications to numerous field crops (including soybeans, tomatoes, and almonds), landscape ornamentals, golf course turf, and as a seed treatment for cereal crops, canola, cotton, and potato seed pieces. It is also registered for post-harvest use on various tuberous and corm species (such as arrowroot, cassavas, and sweet potatoes) as well as apples and pears. EPA registered difenoconazole for use as a seed treatment in 1994 and for foliar uses in 2008.

EPA formally initiated registration review for difenoconazole in 2016 with the opening of the registration review docket for the case. The following summary highlights significant milestones that have occurred during the registration review of difenoconazole.

• January 2016 – EPA posted the Difenoconazole Preliminary Work Plan Registration Review(PWP, dated December 21, 2015), the Difenoconazole: Human Health Risk Scoping Document in Support of Registration Review (dated October 1, 2015), the Difenoconazole: Preliminary Problem Formulation for Environmental Fate, Ecological Risk, Endangered Species, and Drinking Water Exposure Assessments in Support of Registration Review (dated November 5, 2015), and other supporting documents to the public docket for a 60-day public comment period.
  
  

• June 2016 – EPA posted the Difenoconazole Final Work Plan (FWP, dated June 13, 2016) to the public docket. The Agency received five comments on the PWP. The comments did not result in changes to the registration review timeline or data needs as described in the FWP.
  
  

• January 2017 – EPA issued a generic data call-in (GDCI) for difenoconazole to obtain data needed to conduct the registration review risk assessments (GDCI- 128847-1602). All data were submitted and reviewed. All data requirements have been fulfilled and the DCI is satisfied.
  
  

• November 2020 – EPA posted the Difenoconazole Draft Human Health Risk Assessment for Registration Review (dated September 18, 2020) and the Difenoconazole: Draft Ecological Risk Assessment for Registration Review (dated September 16, 2020) for a 60-day public comment period. The Agency received comments from 6 commenters. The comments did not change the risk assessments or registration review timeline for difenoconazole.
  
  

• July 2021 – EPA posted the PID for difenoconazole for a 60-day public comment period. The Agency received comments from 6 commenters. The comments did not change the risk assessments or registration review timeline for difenoconazole. However, comments did result in minor clarification changes to the labeling.
  
  

• April 2022 – EPA posted the ID for difenoconazole to the public docket.