Chlorpyrifos Update

October 21-22, 2020 Pesticide Program Dialogue Committee Meeting

Background:

•	Chlorpyrifos has been a widely used pesticide since 1965. Since its first registration, chlorpyrifos has
been reviewed by EPA for tolerance reassessment and reregistration. It is currently undergoing a
registration review that must be completed before October 2022.

•	In July 2019, EPA denied the objections to EPA's March 2017 order denying a 2007 petition that asked
the agency to revoke all pesticide tolerances and registrations for chlorpyrifos. In that order, the
agency noted it anticipated making available any updates to the human health and drinking water
assessments for public availability by summer 2020 and the Proposed Interim Decision (PID) by October
2020.

•	On August 7, 2019, a petition was filed with the Ninth Circuit Court by the initial petitioners challenging
EPA's July 2019 denial order. Oral arguments were heard on July 28, 2020.

•	In September 2020, EPA issued the following assessments: Chlorpyrifos: Draft Ecological Risk
Assessment for Registration Review, the Chlorpyrifos: Revised Human Health Risk Assessment for
Registration Review, and the Chlorpyrifos Drinking Water Assessment for Registration Review: Update.

•	EPA anticipates issuing the chlorpyrifos registration review PID by November 2020.

Key Points:

•	The revised human health risk assessment, which incorporates the updated drinking water assessment,
identifies dietary (including children) and occupational handler risks of concern.

•	With the limited remaining residential uses of chlorpyrifos, EPA found no risks of concern, including to
children's health, when products are used according to the label instructions.

•	The assessment presents potential risks with the retention of the 10-fold Food Quality Protection Act
(FQPA) Safety Factor, reflecting uncertainties around chlorpyrifos doses that may cause pre- and post-
natal neurodevelopmental effects. The assessment also presents potential risks with a reduced FQPA
Safety Factor, to illustrate the potential range of risks with different FQPA Safety Factors.

•	The Agency's draft ecological risk assessment identifies potential adverse effects to mammals, birds,
fish, and terrestrial and aquatic invertebrates.

•	In September 2020, EPA's Office of Pesticide Programs (OPP) in collaboration with the Office of
Research and Development (ORD) convened a meeting of the FIFRA Scientific Advisory Panel (SAP) for
the review of new approach methods (NAMs) for developmental neurotoxicity that could possibly
inform human health risk assessment for organophosphate (OP) pesticides, including chlorpyrifos, in
the future. The SAP's report is expected in December 2020.

•	After carefully considering those conclusions of the SAP and public comments on the risk assessments
and PID, EPA will then determine the next steps in the registration review process for chlorpyrifos.


-------