Bergeson & Campbell, P.C. serves small, medium, and large pesticide product registrants and other stakeholders in the agricultural and biocidal sectors, in virtually every aspect of pesticide law, policy, science, and regulation.

By Lisa M. Campbell and Timothy D. Backstrom

On March 8, 2016, the U.S. Environmental Protection Agency (EPA) published a notice in the Federal Register stating that the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Scientific Advisory Panel (SAP) will hold a three-day meeting scheduled for April 19-21, 2016, from 9:00 a.m. to 5:00 p.m. (EDT) to consider and review Chlorpyrifos:  Analysis of Biomonitoring Data.  The meeting will be held at EPA’s Conference Center, Lobby Level, One Potomac Yard (South Bldg.), 2777 S. Crystal Drive, Arlington, Virginia 22202.  The meeting will be webcast.  More information will be posted online.

The notice states that written comments are encouraged through April 5, 2016, and that requests for oral comments are encouraged to be submitted by April 12, 2016, but that both may be submitted until the date of the meeting.  Nominations of candidates to serve as ad hoc members of FIFRA SAP for the meeting are requested on or before March 23, 2016.

In this meeting, EPA states that it will solicit comment from FIFRA SAP on the evaluation of biomonitoring data using the physiologically-based pharmacokinetic (PBPK) model, proposed points of departure and extrapolation/uncertainty factors, and examples of a proposed approach to use the PBPK model to simulate internal doses of chlorpyrifos from current exposure patterns from drinking water, food, and worker exposure.  The FIFRA SAP has been reviewing the human health effects of chlorpyrifos since 2008.  The notice states that “at this point in time, the Agency’s analysis of biomonitoring data from the cord blood collected as part of the Columbia University epidemiology studies has progressed to a point where peer review would be useful” and that “[s]pecifically, the Agency has done additional characterization of the pharmacokinetic profile of simulated exposures from oral and dermal exposures using the PBPK model.”

The notice states that in 2008 and 2012, the FIFRA SAP “cautioned EPA against using the biomonitoring data from epidemiology studies … to directly derive points of departure due to uncertainties associated with a lack of knowledge about timing of indoor chlorpyrifos applications and a single measure of exposure (cord blood).”  The 2012 FIFRA SAP recommended that EPA use the PBPK model to further characterize the dose estimates in the epidemiology studies.

The notice states that EPA would have preferred to complete its analysis of the available biomonitoring prior to commencing rulemaking, but that the timing for the proposal was directed by the U.S. Court of Appeals for the Ninth Circuit, which ordered EPA to respond to an administrative petition to revoke all chlorpyrifos tolerances by October 31, 2015.

More information on the Ninth Circuit case is available in our blog item Circuit Court Grants Writ of Mandamus Requiring EPA to Act on Petition to Ban Chlorpyrifos.

Commentary

EPA’s decision to utilize biomonitoring data that was collected as part of the Columbia University epidemiology studies for chlorpyrifos to derive proposed points of departure for risk assessment purposes will be highly controversial.  If EPA proceeds to use biomonitoring data from epidemiological studies to derive points of departure for risk assessment purposes, the implications for all pesticide product risk assessments could be significant.  Whether EPA can defensibly do so from both a scientific and legal standpoint is a subject that will likely be debated strongly.  All pesticide registrants should monitor these developments closely.  


 

By Lisa M. Campbell, Timothy D. Backstrom, and Susan Hunter Youngren, Ph.D.

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.


 

By Lisa M. Campbell, Timothy D. Backstrom, and James V. Aidala

On June 10, 2015, the Ninth Circuit Court of Appeals granted a petition for a writ of mandamus for a petition filed by Pesticide Action Network North America and Natural Resources Defense Council in 2007. That petition requested that EPA cancel all registrations and revoke all tolerances for the insecticide chlorpyrifos. An order granting a writ of mandamus is unusual, and indicates that the Court is impatient about what it perceives to be the slow pace of review by the U.S. Environmental Protection Agency (EPA). The petitioners previously sought such a writ in 2012, and the Court denied that request without prejudice in 2013. EPA took action in 2012 that addressed seven out of the ten issues originally raised by the petitioners, and the Court found in 2013 that the time taken by EPA to address the petition was “not unreasonable in light of the complexity of the issue.” On March 26, 2015, EPA wrote to the petitioners stating that it intends to deny their petition to cancel registrations and revoke tolerances for chlorpyrifos. EPA bases this anticipated decision on a new human health risk assessment incorporating a physiologically based pharmacokinetic-pharmacodynamic (PBPK-PD) model that allows EPA to estimate human risk directly rather than extrapolating from animal data. Based on this model, EPA determined that label changes are needed to mitigate certain occupational exposures and localized drinking water exposure, and has requested comment on these findings.

EPA counsel represented during oral argument in the case that EPA could complete its review of the comments and take action on the petition by mid-September 2015. In response, the Court has issued an order directing EPA either to submit a status report by June 30, 2015, stating whether EPA intends to finalize its preliminary denial, or whether EPA has decided instead to grant the petition in whole or in part. If the petition will be denied, EPA must issue the final denial decision by September 15, 2015.

Commentary

The schedule imposed by the Court order is demanding, but it is likely that EPA will make every effort to meet it. The Court did not require EPA to respond to all of the comments on the risk assessment, or to determine what mitigation measures will ultimately be required, by the September deadline. Although EPA would normally prefer to complete all related tasks and to compile a comprehensive administrative record before issuing the final decision denying the petition to cancel chlorpyrifos, that would be very challenging to do in this instance. The comment period for the current risk assessment closed on April 30, 2015, and EPA must evaluate and respond to detailed comments on a complex assessment, one which has some important issues subject to serious dispute by the affected registrants. For example, Dow Agrosciences LLC submitted a 130 page set of comments on April 29, 2015, in addition to comments received from the general public, users of the pesticide, and other interested parties. If EPA determines it will proceed with its stated intent to deny the petition to cancel, this action may precede the mitigation measures that EPA imposes based on the chlorpyrifos risk assessment and the comments on that assessment. Nevertheless, because the petitioners are likely to challenge the denial decision as well, EPA will need to prepare an adequate explanation of the reasons for the denial and to expedite the related administrative actions to the extent that is practicable.


 
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