Bergeson & Campbell, P.C.

EPA Requests Comments on Revocation of Chlorpyrifos Tolerances


On October 30, 2015, the U.S. Environmental Protection Agency (EPA) announced that it is requesting comments on a proposal to revoke all tolerances for the insecticide chlorpyrifos. EPA issued this proposal in response to an August 10, 2015, writ of mandamus by the U.S. Court of Appeals for the Ninth Circuit. The court granted this unusual relief in response to a 2007 administrative petition to cancel chlorpyrifos registrations or to revoke chlorpyrifos tolerances by the Pesticide Action Network North America (PANNA) and the Natural Resources Defense Council (NRDC) (together, Petitioners). The court’s August 10, 2015, order required that EPA do one of the following by October 31, 2015: (a) cancel the registrations of all pesticides containing chlorpyrifos; (b) issue a proposed or final rule to revoke chlorpyrifos tolerances; or (c) issue a full and final response to the administrative petition to cancel chlorpyrifos. More information on that decision is available in our blog item Circuit Court Grants Writ of Mandamus Requiring EPA to Act on Petition to Ban Chlorpyrifos.

In its announcement, EPA states that it “is not denying the petition because we are unable to make a safety finding based on the science as it stands currently. EPA is not issuing a final revocation rule because we have not proposed it and have not completed our refined drinking water assessment, leaving certain science issues unresolved.” The court also required EPA to provide the timeline for a final rule should EPA issue a proposed revocation by October 31, and EPA notified the court of an anticipated date for a final rule of December 2016. EPA will release a completed hazard assessment and a completed drinking water analysis for comment prior to issuance of any final rule.

Because EPA has not completed its hazard assessment and drinking water analysis, this means that EPA may resolve the “science issues” without the need for tolerance revocations. The proposal is based not on the risk posed by chlorpyrifos residues in food, but on the incremental risk posed by chlorpyrifos in drinking water in very specific and limited watersheds where chlorpyrifos is heavily used. EPA is required to consider such exposures in evaluating the safety of chlorpyrifos residues in food under the Federal Food, Drug, and Cosmetic Act, as amended by the Food Quality Protection Act (FQPA). If the tolerances are revoked, this will result in cancellation of the associated food uses of chlorpyrifos.

The chlorpyrifos registrant Dow AgroSciences and other pesticide industry representatives do not agree with the EPA analysis or the proposal to revoke the tolerances. In particular, questions have been raised about EPA’s decision to retain the use of a 10X FQPA safety factor for infants and children based on certain epidemiology studies. EPA has acknowledged that these studies have significant limitations and that they cannot identify a specific level of concern for quantitative risk assessment. EPA has previously reduced the FQPA safety factor for chlorpyrifos to one based on the completeness of the toxicological database. If the 10X FQPA safety factor were reduced to one or even to three, the results of the current risk assessment would be very different.

Additional information, including the pre-publication version of the proposed rule, is available here.

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