By Lisa R. Burchi and Barbara A. Christianson

On December 2, 2021, the U.S. Environmental Protection Agency (EPA) announced it released the registration review schedule for the next four years through fiscal year (FY) 2025. While historically this schedule has been updated once each year, EPA states that going forward it will be updated on a quarterly basis.

The 2007 amendment of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) requires that EPA review each registered pesticide at least every 15 years. For the 726 pesticide cases that were registered before October 1, 2007, the amendment to FIFRA requires EPA to complete its review by October 1, 2022. This is significant, as it is intended to mark the end of the first 15-year registration review cycle.

Working toward that goal, EPA states that it has completed the following over the past 15 years:

• Issued more than 550 interim or final decisions;
• Completed more than 600 proposed interim decisions;
• Conducted more than 680 human health and ecological draft risk assessments (excluding endangered species assessments);
• Imposed new risk mitigation requirements for 51 percent of antimicrobial pesticides and 70 percent of conventional pesticides for which EPA issued an interim or final decision; and
• Canceled some or all uses in 120 cases.

EPA states its updated registration review schedule provides a “roadmap” for the next four years of EPA’s registration review program. EPA’s schedule includes 297 entries describing the registration review “action” (e.g., Draft Risk Assessment, Proposed Interim Decision, Interim Decision, Preliminary Work Plan, Final Work Plan) to be addressed by EPA’s different divisions (e.g., Pesticide Reevaluation Division; Antimicrobials Division, Biopesticides and Pollution Prevention Division). Throughout its review, EPA makes the information, assessments, and supporting material for each case available to the public at regulations.gov.

Significantly, but not surprisingly, EPA acknowledges that for some pesticides registered before October 1, 2007, it “anticipates that its review will extend beyond” the October 1, 2022, deadline “due to a number of challenges including delays in receiving data from registrants; the demands of responding to COVID-19; and a significant increase in recent years of resources devoted to litigation.” EPA also warns that the schedule is “subject to change based on shifting priorities and is intended to be an estimated timeline.” EPA notes further that data that are not submitted on time may affect EPA’s registration review timeline and that “several cases are not found on the schedule due to uncertainty of when necessary data will be received.”

Complying with the Endangered Species Act (ESA) is also part of the registration review process. Since 2007, EPA states that it has completed ESA assessments for certain high-priority pesticides and, in the coming years, plans to assess the effects of many more pesticides on endangered species in registration review. According to EPA, it will release its first ESA pesticides work plan in the coming months, which will outline steps EPA will take to come into compliance with the ESA in ways that are fair and transparent to the agriculture sector.

Information on EPA’s registration review process is available here.

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By Lisa M. Campbell, Lisa R. Burchi, and James V. Aidala

On December 7, 2020, the U.S. Environmental Protection Agency (EPA) issued for comment the Proposed Interim Decision (PID) for chlorpyrifos.  85 Fed. Reg. 78849.  EPA announced it is proposing new risk mitigation measures to address potential human and environmental risks identified in EPA’s September 2020 draft risk assessments.  The PID proposes the following measures:

• Label amendments limiting application to address potential drinking water risks of concern.
• Additional personal protection equipment and application restrictions to address potential occupational handler risks of concern.
• Spray drift mitigation, in combination with the use limitations and application restrictions identified to address drinking water and occupational risks, to reduce exposure to non-target organisms.

EPA states that the PID presents proposed mitigation with the 10-fold (10x) Food Quality Protection Act (FQPA) safety factor, reflecting the uncertainties around doses that may cause pre- and post-natal neurodevelopmental effects.  Under FQPA, EPA evaluates new and existing pesticides to ensure they can be used with a reasonable certainty of no harm to infants, children, and adults.  EPA is required to consider the special susceptibility of children to pesticides by using an additional 10x safety factor unless adequate data are available to support a different factor.  EPA additionally included a FQPA factor of 1x to reflect the range of potential risk estimates of chlorpyrifos, as illustrated in the September 2020 draft risk assessments.

Comments on both the September 2020 draft risk assessments and the PID are due on or before February 5, 2021.  EPA states that by holding the comment period for both actions at the same time, the public has access to more information and can provide more informed, robust comments.  Comments can be submitted at EPA-HQ-OPP-2008-0850.

EPA announced that it will also consider the input and recommendations from the September 2020 Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Scientific Advisory Panel (SAP) meeting once it releases its report in December 2020.  Depending on the SAP’s conclusions, EPA may further revise the human health risk assessment. 

Commentary

The inclusion of both 1x and 10x calculations for the appropriate FQPA safety factor is unusual.  EPA states the final decision on the appropriate FQPA safety factor is partly dependent on any recommendations expected from the SAP meeting, which reviewed the “use of new approach methodologies (NAMs) to derive extrapolation factors and evaluate developmental neurotoxicity for human health risk assessment.”  This is part of a larger and longer evaluation of whether test methods that avoid using test animals can reliably substitute for current test guideline requirements, that is, whether it is appropriate to rely on in vitro test protocols to substitute for current in vivo testing protocols.

EPA’s articulation at this point in time of mitigation needed if the FQPA 10x safety factor is retained may indicate a prediction about the SAP’s likely recommendations.  It will be important to monitor developments on this issue closely.

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By Timothy D. Backstrom

On February 3, 2020, the U.S. Environmental Protection Agency (EPA) issued a Federal Register notice announcing the availability of an interim registration review decision for glyphosate.  EPA previously issued a proposed interim registration review decision (PID) for glyphosate for comment in April 2019.  At the time EPA issued the glyphosate PID for comment, EPA also issued a draft human health risk assessment and a preliminary ecological risk assessment for glyphosate.  After reviewing the comments received concerning these assessments, EPA has not made any revisions to either assessment.  EPA has determined that there are no dietary, residential, bystander, or occupational human health risks of concern associated with glyphosate use.   EPA has also determined that there are some potential risks to plants, birds, mammals, and invertebrates from glyphosate use, but that these can be appropriately mitigated by label changes requiring enforceable spray drift management measures and adding a warning concerning the potential hazards to non-target organisms.  EPA also has proposed some new measures to manage the development and spread of herbicide-resistant weeds.  EPA has generally retained the proposed labeling changes identified in the PID, except for some modest adjustments to the proposed language concerning droplet size restrictions and swath displacement restrictions for aerial applications, and removal of spray drift advisory language for airblast application.

Despite considerable publicity recently concerning purported carcinogenic risks for glyphosate, including allegations that human exposure to glyphosate can be linked to non-Hodgkin's lymphoma, EPA has determined that glyphosate is not likely to be a human carcinogen and has steadfastly adhered to this basic conclusion.  EPA made this determination for glyphosate after convening a meeting of the FIFRA Scientific Advisory Panel (SAP) to evaluate the carcinogenic potential of glyphosate in 2016.

The general purposes of the PID process are to allow EPA to move forward with aspects of the registration review process that are essentially complete, and to adopt interim risk mitigation measures, even though some of the actions required prior to a final registration review decision are not yet complete.  As in the case of most recent PIDs, EPA states that it has not yet made a complete determination concerning potential effects or any required consultation for glyphosate under the Endangered Species Act (ESA), nor has it made a determination for glyphosate under the Endocrine Disruptor Screening Program (EDSP).  In addition, EPA is considering a pending petition to prohibit preharvest use of glyphosate on oats, and to reduce the tolerance for glyphosate in oats, that was filed in 2018 by the Environmental Working Group and others.  This petition is predicated on the potential carcinogenicity of glyphosate.  Finally, EPA is still evaluating the question of whether additional data will be needed to evaluate properly the potential effects of glyphosate use on pollinators.  

More information on glyphosate and EPA’s interim registration review decision is available here.

Commentary

EPA's interim registration review decision for glyphosate is predicated on EPA's prior determination that the best available scientific data do not substantiate the claims that glyphosate may be a human carcinogen.  As discussed above, the potential carcinogenicity of glyphosate was thoroughly evaluated by the FIFRA SAP in 2016.  EPA's determination after that review that glyphosate is not a carcinogen has also been supported by other pesticide regulatory authorities.  Nonetheless, EPA's view conflicts with a cancer classification decision for glyphosate by the World Health Organization (WHO), and with some recent tort case decisions that were based on the premise that there is a credible linkage between glyphosate exposure and human cancer.  EPA recently announced that it would not permit or approve any cancer warning statements for inclusion in glyphosate labeling (including any statements that may be required pursuant to California's Prop 65) because EPA believes that such statements are false or misleading and would therefore cause the pesticides to be "misbranded."

It appears probable there will be continued litigation based on the purported carcinogenicity of glyphosate, along with various proposals to ban or restrict glyphosate use.  The pending petition to restrict use of glyphosate on oats that was filed by EWG, et al., is expressly predicated on the potential carcinogenicity of glyphosate, so it appears probable that this petition will ultimately be denied by EPA.  Nonetheless, unless WHO decides to reverse or modify its classification determination, or the courts determine that the recent tort awards for glyphosate users cannot be scientifically substantiated, the battles over the claimed carcinogenicity of glyphosate may persist for years.

More information on glyphosate issues is available on our blog under keyword glyphosate.

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By Timothy D. Backstrom and James V. Aidala

On December 18, 2019, the Office of Pesticide Programs (OPP) of the U.S. Environmental Protection Agency (EPA) issued for comment a Proposed Interim Decision (PID) in the ongoing registration review process for each of the three registered triazine herbicides: atrazine, propazine, and simazine.  EPA will allow 60 days for comment on each of these triazine PIDs, but the specific comment deadline will only be established after EPA has published notice concerning the proposed interim decisions in the Federal Register.  EPA can utilize an “interim registration review decision” under 40 C.F.R. Section 155.56 whenever it is not yet ready to complete the registration review process, but EPA has nonetheless completed sufficient review to determine that new or interim risk mitigation measures are needed or that additional data or information should be submitted to complete the review.  For each of the three triazine herbicides, EPA is proposing to impose specific risk mitigation measures for particular registered uses to mitigate potential health and environmental risks.  For each triazine herbicide, EPA is not yet ready to make a final registration review decision because EPA has not made findings in the Endocrine Disruptor Screening Program (EDSP) or an effects determination under the Endangered Species Act (ESA).  Several key factors that will affect the final registration review decision for each of the triazine herbicides are discussed below.

Common Factors for Triazine Risk Assessment

There are several common factors to consider with regard to the triazines risk assessment.  These include:

1. Atrazine, propazine, and simazine are all included in the chlorotriazine chemical class.  EPA has determined that these three herbicides, along with three specific chlorinated metabolites, share a common mechanism of toxicity, so human health risks from all of these substances are being assessed by EPA together through one cumulative triazine risk assessment. The contribution of each product to aggregate human risk differs because of somewhat dissimilar use patterns. The combining of risks resulting from use of each triazine means, however, that it may be necessary for EPA to coordinate the ultimate registration review decisions for the three active ingredients.
2. As part of the ecological risk assessment for each triazine herbicide, EPA plans to make an effects determination for potentially vulnerable species under the ESA, which in turn will determine whether it is necessary for EPA to consult with the Fish and Wildlife Service or the National Marine Fisheries Service (the Services) concerning potential impacts of each active ingredient and relevant metabolites on endangered or threatened species.  Atrazine, propazine, and simazine are all included in a stipulated settlement between the parties in Center for Biological Diversity et al. v. EPA et al. No. 3:11 cv 0293 (N.D. Cal.), and EPA agreed in that stipulated settlement to set August 14, 2021, as the deadline for EPA to make a nationwide effects determination for each active ingredient, and to request any required consultation with the Services, under ESA Section 7(a)(2).
3. EPA states that the predominant human health effect of concern for all three of the triazine herbicides and their chlorinated metabolites is potential suppression of the luteinizing hormone (LH) surge, which is considered to be both a neuroendocrine and a developmental effect.  Atrazine and simazine were both included on List 1 for screening testing under the EDSP required by the Food Quality Protection Act (FQPA) amendments.   All of the required Tier 1 screening assays for each of these substances are complete and have been evaluated by EPA, but EPA has not yet made human health or environmental findings under the EDSP.  The EDSP screening testing has not been completed yet for propazine.

Risk Mitigation Measures

Each PID proposes specific risk mitigation measures intended to address potential human and environmental risks identified by the EPA risk assessments.

For atrazine, the PID includes the following measures to mitigate aggregate human risk:

• Reduce the permissible application rates for use of granular and liquid formulations on residential turf.
• Require additional personal protective equipment (PPE) and engineering controls for certain uses.
• Restrict aerial applications to liquid formulations only.
• Limit backpack sprayer applications to landscape turf to spot treatment only.
• Prohibit pressurized handgun application to certain commodities.

To mitigate ecological risks, the atrazine PID proposes to require various spray drift reduction measures, to add a non-target advisory statement to labeling, and to adopt a nationwide stewardship program.

For propazine, the PID proposes to cancel the greenhouse use to mitigate aggregate human risk.  Ecological risks would be mitigated by proposing to require various spray drift reduction measures and by adding a non-target advisory statement to labeling.

For simazine, the PID includes the following measures to mitigate aggregate human risk:

• Cancel simazine use on residential turf.
• Require additional PPE and engineering controls for certain uses.
• Limit pressurized handgun applications to certain commodities to spot treatment only.

Ecological risks would be mitigated by proposing to require various spray drift reduction measures and by adding a non-target advisory statement to labeling.

Commentary

In each of the PIDs for the triazine herbicides, EPA has focused its efforts on adopting mitigation measures which should be efficacious in reducing human and ecological risks without materially impairing the availability of the products in question for key agricultural uses.  In some instances, the PID documents explicitly state that the product registrants have agreed to proposed changes.  An EPA Pesticide Program Update dated December 19, 2019, that discusses the interim decision for atrazine includes statements of support from several grower groups.

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By Timothy D. Backstrom

On December 5, 2019, the U.S. Environmental Protection Agency (EPA) Office of Pesticide Programs (OPP) announced the availability of a revised interim registration review decision for use of sodium cyanide in the M-44 predator control device.  The M-44 device is a restricted use pesticide (RUP) and may be used only by certified applicators in compliance with specific mandatory restrictions set forth on the label.  Although the registration review process for sodium cyanide remains pending, EPA has decided to issue an interim decision for the M-44 device now to adopt new label restrictions intended to mitigate potential risks.  The revised interim decision adopts two new restrictions and also modifies certain existing restrictions, which EPA states "will reduce the potential for unintended impacts on humans, pets, and other non-target animals.”

The M-44 predator control device uses a spring-loaded ejector to fire a capsule containing a single lethal capsule of sodium cyanide.  The M-44 is used by livestock producers to control predators (primarily coyotes) that kill sheep, goats, and cattle.  Registrations for the M-44 device are currently held by the U.S. Department of Agriculture, and by five individual States (South Dakota, Texas, Montana, Wyoming, and New Mexico) where livestock predation has been a particular problem.

New or revised restrictions that will be incorporated in the approved labeling for the M-44 device include:

• Requiring a 600-foot buffer zone around residences where an M-44 cannot be used (except for a cooperating landowner who has given written permission).
• Requiring that the applicator notify occupants of all residences within a 0.5 mile radius (by face-to-face communication, person-to-person telephone communication, door hanger, or certified mail) prior to an M-44 placement.
• Increasing from 50 feet to 300 feet the distance from designated public paths and roads where M-44 use is prohibited.
• Requiring two elevated warning signs placed 15 feet from the M-44 device and facing the most likely directions of approach, instead of one elevated sign placed 25 feet from the device.

Commentary

Livestock producers and State departments of agriculture contend that the M-44 device is essential to limit economic losses resulting from predation, which reportedly amount to hundreds of millions of dollars annually.  In contrast, wildlife advocates have strongly opposed any continued use of the M-44 device.  In 2017, WildEarth Guardians and the Center for Biological Diversity petitioned EPA to suspend and cancel all registrations for M-44 capsules, but EPA concluded that the petition did not contain substantial new information and denied the petition in 2018.  Although the new and modified label restrictions adopted by EPA in the interim decision for the M-44 device are not likely to satisfy opponents, these changes should nonetheless reduce the likelihood that humans, pets, or other non-target species will be exposed to the M-44 capsules or the toxin they contain.

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By Lisa M. Campbell and Timothy D. Backstrom

On August 7, 2019, the League of United Latin American Citizens, Pesticide Action Network North America, Natural Resources Defense Council, and other petitioners (Petitioners) filed a new petition in the Ninth Circuit Court of Appeals seeking judicial review of United States Environmental Protection Agency (EPA) orders denying their request that EPA revoke all tolerances and cancel all registrations for chlorpyrifos.  On August 8, 2019, New York, California, Hawaii, Maryland, Vermont, Washington, Massachusetts, and the District of Columbia (States) also filed a new petition for judicial review concerning the refusal of EPA to ban chlorpyrifos.  The Petitioners and the States seek judicial review of the July 18, 2019, final order by EPA dismissing all objections to the initial decision by EPA to retain tolerances and registrations for chlorpyrifos, and of EPA’s March 29, 2017, order that initially denied a 2007 petition to revoke all tolerances and cancel all registrations for chlorpyrifos.

The Petitioners and the States also seek consolidation of their newly filed petitions for judicial review with currently pending chlorpyrifos litigation in LULAC, et al. v. Wheeler, et al.  As part of rehearing in the LULAC case, the Ninth Circuit vacated a prior decision that ordered EPA to cancel chlorpyrifos registrations, and instead issued a writ of mandamus requiring EPA to respond to objections to the 2017 denial order within 90 days.  EPA then issued the July 18, 2019, order denying all objections, along with a motion on July 19, 2019, to dismiss the LULAC case as moot.  EPA seeks dismissal of LULAC because it contends that the 2017 initial order was never itself reviewable, and EPA has now done everything that the writ of mandamus required. The Petitioners oppose the motion to dismiss because it would require the Court to take a position on a jurisdictional issue which they contend was not decided during rehearing.  The Petitioners and the States also argue that dismissal would be unnecessary and inefficient, requiring the challenging parties to reconstitute the record for review compiled in LULAC.

Petitioners also note that the Ninth Circuit retained jurisdiction when it issued mandamus in LULAC, and they request that their combined challenge to the EPA decision to retain the existing tolerances and registrations for chlorpyrifos be heard by the Court en banc as well.

Commentary

The latest petitions for judicial review of EPA’s 2019 decision to retain all tolerances and registrations for chlorpyrifos pending registration review were anticipated by all parties, and all parties agree that the procedural requisites for a judicial determination concerning the legality of EPA’s final decision to deny the 2007 administrative petition have now been satisfied.  The Petitioners and the States will likely argue that prior scientific determinations by EPA, including EPA analysis of epidemiology studies that purport to establish a link between exposure to chlorpyrifos and adverse neurodevelopmental effects in children, require that EPA proceed to revoke all tolerances and cancel all registrations for chlorpyrifos, while EPA will likely argue that difficult scientific issues concerning chlorpyrifos remain unresolved and should be addressed by EPA as part of the pending registration review for chlorpyrifos.

In addition to the dispute about combining the new petitions for review with the LULAC case, an interesting element of the latest filing by the Petitioners is that they attempt to bootstrap en banc review of the 2019 order in which EPA finally denied the administrative petition to revoke tolerances and cancel registrations for chlorpyrifos.  En banc review for an initial hearing (as opposed to en banc rehearing in a previously decided case) is allowed by the applicable appellate rules, but such review is disfavored and would be highly unusual.  Petitioners argue that it is warranted here because the en banc panel in the rehearing in the LULAC case reserved jurisdiction.  Given the motion by EPA to dismiss the LULAC case as moot, it can be presumed that EPA is likely to oppose this vicarious argument for en banc judicial review.   EPA can argue that the only reason the en banc panel retained jurisdiction was to assure that EPA would timely comply with the writ of mandamus that required EPA to rule on the objections within 90 days.

For further information on the long history of litigation concerning the petition to ban chlorpyrifos, please review our prior blog entries.

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

On August 2, 2019, the U.S. Environmental Protection Agency (EPA) Office of Pesticide Programs (OPP) announced that it has decided to reduce the Food Quality Protection Act (FQPA) safety factor for infants and children for pyrethroids from its current value of 3X to a new value of 1X.  This decision is based on a July 1, 2019, OPP report entitled “USEPA Office of Pesticide Programs’ Re-evaluation of the FQPA Safety Factor for Pyrethroids: Updated Literature and CAPHRA Program Data Review.”  Risk assessments incorporating the new lower FQPA safety factor for pyrethroids will be utilized in developing proposed registration review decisions for these compounds, and EPA has stated it will be taking public comment on the OPP report reducing the FQPA safety factor for pyrethroids after EPA publishes a notice of availability for the proposed registration review decisions.

Pyrethroids are a group of insecticides that includes natural pyrethrins (found in chrysanthemums) and more than 30 synthetic compounds with similar structure and activity. EPA has determined that it is appropriate to establish one FQPA safety factor for all pyrethroid active ingredients because these compounds all have the same mode of action and similar patterns of toxicity.  Pyrethroid insecticides are widely used in and around residential structures, on pets, in treated clothing, for mosquito control, and in various agricultural applications.  EPA indicates that although pyrethroids have relatively low mammalian toxicity, EPA believes that the principal concern for human risk assessment is a potential to cause acute neurotoxic effects.

The FQPA safety factor is intended to account for “potential pre- and post-natal toxicity and completeness of data with respect to exposure and toxicity to infants and children.”  The FQPA safety factor is set by statute at a default value of 10X, but EPA may select a lower value for this safety factor if EPA determines based on “reliable data” that such a lower value will be safe for infants and children.  This determination necessarily depends on EPA’s assessment of the quality of the data that address the susceptibility to adverse effects of the pesticide of infants and children.  Based on current EPA guidance, OPP evaluates the need for the default FQPA safety factor of 10X in two components: a safety factor of about 3X assigned to pharmacodynamic (PD) differences and a safety factor of about 3X assigned to pharmacokinetic (PK) differences.  PD differences refer to the sequence of events at the molecular or cellular level leading to a toxic response to a substance, while PK differences refer to absorption, distribution, metabolism, and excretion of the substance.

EPA previously evaluated the adequacy of the database concerning risks to infants and children posed by pyrethroid active ingredients in 2011.  At that time, EPA decided that there were sufficient data concerning the mechanism for potential neurotoxic effects of pyrethroids to allow EPA to reduce the factor for PD differences to 1X, but EPA retained the 3X factor for PK differences because EPA believed that the available pharmacokinetic data for pyrethroids was not sufficient for EPA to conclude that infants and children would not confront a greater risk of neurotoxic outcomes.  After EPA made the 2011 determinations, the Council for the Advancement of Pyrethroid Human Risk Assessment (CAPHRA) conducted a variety of additional research to address whether children are more sensitive to the neurotoxic effects of pyrethroid exposure, and this research assessed both PD and PK differences.  CAPHRA submitted a peer-reviewed physiologically based pharmacokinetic (PbPk) model for pyrethroids to EPA in 2018.  After reviewing the new CAPHRA data and the current public literature for pyrethroids, EPA has now concluded that the factor for PD differences should be maintained at 1X, but the factor for PK differences should be reduced from 3X to 1X.  Collectively, these determinations mean that EPA has concluded that there are reliable data to support a determination that infants and children are not more susceptible to the neurotoxic effects of pyrethroids than adults, so there is no need to retain either the default FQPA safety factor of 10X or the previous FQPA safety factor used for pyrethroids of 3X.

Commentary

The adoption by EPA of a new FQPA safety factor of 1X for all pyrethroid active ingredients will likely facilitate retention of existing use patterns and use directions for a large number of pyrethroid insecticides that are commonly used in and around human residences and workplaces.

From a larger perspective, the process by which EPA evaluated and selected a proposed FQPA safety factor for pyrethroids may be seen as typical for most pesticides or classes of pesticides.  The selection of a FQPA safety factor for a particular pesticide usually is based on review of available animal data, including PD and PK data, to determine whether there is any basis for concluding that infants and children may be more susceptible to adverse effects of that pesticide than adults.  Where EPA decides that the animal data addressing this question are insufficient, affected registrants and other proponents of registration can consult with EPA concerning studies that will address the uncertainties.  Depending on the outcome of such studies, EPA may be able to conclude that there is a scientific basis for a partial or complete reduction of the default FQPA safety factor.

Compared to this typical evaluation process, the recent decision by EPA to retain the default FQPA safety factor for all organophosphate (OP) active ingredients, which was based on EPA’s interpretation of neurodevelopmental effects reported at low exposure levels (below the threshold for acetylcholinesterase inhibition) in epidemiology studies for chlorpyrifos, may be seen as an aberration.  EPA’s decision to rely on epidemiology studies that may be susceptible to methodological biases, and the decision to utilize epidemiology studies for chlorpyrifos to set the FQPA safety factors for all OP pesticides, have both been controversial.

EPA’s recent decision to retain the current tolerances and registrations for chlorpyrifos was based in significant part on EPA’s interpretation of a PbPk model for chlorpyrifos previously submitted by DowAgro (now Corteva), which mitigated to some degree EPA’s retention of the default FQPA safety factor for chlorpyrifos.  Corteva may submit further data addressing PD and PK differences for chlorpyrifos, and EPA has also stated that it intends to review some new animal studies for chlopyrifos, which purport to show neurodevelopmental effects at low exposure levels.  Perhaps these data will allow EPA to establish a point of departure (POD) for chlorpyrifos risk assessment without any need for a further excursion into the unfamiliar risk assessment territory represented by EPA’s use of epidemiology data for chlorpyrifos.

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

On July 18, 2019, the U.S. Environmental Protection Agency (EPA) issued a pre-publication version of a Federal Register notice announcing a final order denying the Pesticide Action Network North America’s (PANNA) and the Natural Resources Defense Council’s (NRDC) 2007 Petition requesting that EPA revoke all tolerances and cancel all registrations for chlorpyrifos (Order).  This Order constitutes final Agency action denying all of the Petitioners’ objections to EPA’s previous refusal to revoke the tolerances for chlorpyrifos.  This Order also constitutes final administrative action concerning all parts of the 2007 Petition that were not previously addressed by EPA.  Given the previous extensive chlorpyrifos litigation, this latest action by EPA will likely lead to further litigation challenging EPA’s decision to allow continued use of chlorpyrifos under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and the Federal Food, Drug, and Cosmetic Act (FFDCA).

Background

The FIFRA registrations and related tolerances for chlorpyrifos have a complicated regulatory and legal history, as discussed in previous blogs available here.

EPA’s new Order denies objections made by PANNA and NRDC under the FFDCA to EPA’s March 29, 2017, order denying the request by PANNA and NRDC that EPA revoke all tolerances for chlorpyrifos and cancel all chlorpyrifos product registrations.  In the Order, EPA begins by summarizing its prior responses to the 2007 Petition, in which EPA denied each of ten claims raised in support of the Petitioners’ request that EPA revoke all chlorpyrifos tolerances and cancel all chlorpyrifos registrations.  The ten claims are:

1. EPA has ignored genetic evidence of vulnerable populations.
2. EPA has delayed a decision regarding endocrine disrupting effects.
3. EPA has ignored data regarding cancer risks.
4. EPA’s 2006 cumulative risk assessment (CRA) for the organophosphates misrepresented risks and failed to apply the Food Quality Protection Act (FQPA) 10X safety factor.
5. EPA over-relied on registrant data.
6. EPA has failed to address properly the exporting hazard in foreign countries from chlorpyrifos.
7. EPA has failed to incorporate quantitatively data demonstrating long-lasting effects from early life exposure to chlorpyrifos in children.
8. EPA has disregarded data demonstrating that there is no evidence of a safe level of exposure during pre-birth and early life stages.
9. EPA has failed to cite or incorporate quantitatively studies and clinical reports suggesting potential adverse effects below 10 percent cholinesterase inhibition.
10. EPA has failed to incorporate inhalation routes of exposure.

EPA’s Order next focuses on the June 2017 objections to the March 29, 2017, Denial Order that were filed by several public interest groups and states.  The three main objections, and EPA’s response, are as follows:

• Claims Regarding the Legal Standard for Reviewing Petitions to Revoke:  Objectors assert that EPA’s Denial Order applied the wrong legal standard.  Objectors assert that neither “scientific uncertainty” nor the October 2022 deadline for registration review under FIFRA Section 3(g), nor the widespread agricultural use of chlorpyrifos, provide a basis for denying petitions to revoke. Objectors claim that EPA has unlawfully left chlorpyrifos tolerances in place without making the safety finding required by the FFDCA.

• EPA Response:  In its Order, EPA denies the objections related to Petitioners’ claims regarding neurodevelopmental toxicity, stating that the objections and the underlying Petition are not supported by valid, complete, and reliable evidence sufficient to meet the Petitioners’ burden under the FFDCA, as set forth in EPA’s implementing regulations.  Specifically, EPA states that Objectors have not met their regulatory burden to provide “reasonable grounds” for revocation, including an assertion of facts to justify the modification or revocation of the tolerance (40 C.F.R. § 180.32(b)) or the initial evidentiary burden for persons seeking revocation to come forward with sufficient evidence to show that pesticide tolerances to be modified or revoked are not safe.  After summarizing its review of available epidemiologic data, including feedback from the 2012 and 2016 FIFRA Scientific Advisory Panel (SAP) meetings, EPA states that “the epidemiologic studies are central to the Petitioner’s claims regarding neurodevelopmental effects, yet the Petitioners and Objectors rely only on summaries in publications to present their case. Petitioners have not presented the raw data from the epidemiology studies for consideration of their claims.” EPA “concludes that the information yet presented by Petitioners is not sufficiently valid, complete, and reliable to support abandoning the use of AChE inhibition as the critical effect for regulatory purposes under the FFDCA section 408” and also that Petitioners have “failed to meet their initial burden of providing sufficiently valid, complete, and reliable evidence that neurodevelopmental effects may be occurring at levels below EPA’s current regulatory standard and no information submitted with the objections addresses this shortcoming of the Petition.”

• Objections Asserting that EPA Has Found Chlorpyrifos to Be Unsafe: Objectors assert that EPA has previously found that chlorpyrifos tolerances are unsafe and has not disavowed those findings. Specifically, they claim that EPA has found that chlorpyrifos results in unsafe drinking water exposures and results in adverse neurodevelopmental effects to children and that EPA must therefore revoke the tolerances.

• EPA Response:  EPA denies making any regulatory findings that chlorpyrifos tolerances are not safe, stating that its statements in its 2015 proposed tolerance revocation was not a final action.  EPA states: “Proposed rules are just that -- proposals; they do not bind federal agencies. Indeed, EPA made clear it was issuing the proposal because of the court order, without having resolved many of the issues critical to EPA’s FFDCA determination and without having fully considered comments previously submitted to the Agency.”  Regarding those objections related to drinking water, EPA states that since the Petition did not identify drinking water exposure as a basis for seeking tolerance revocation, the Objectors cannot now raise that concern as a basis for challenging EPA’s denial of the Petition. EPA also states: “The mere fact that EPA is considering the potential impact of chlorpyrifos exposures in drinking water in the Agency’s FIFRA section 3(g) registration review does not somehow provide Petitioners and Objectors with a vehicle for introducing that topic in the objections process on the Petition denial.”  EPA instead will continue its FIFRA Section 3(g) registration review and complete its evaluation of drinking water exposures to chlorpyrifos, and address these issues in its upcoming registration review decision.

• Objections Asserting that the Denial Order Failed to Respond to Significant Concerns Raised in Comments:  Objectors argue that EPA’s Denial Order committed a procedural error by failing to address significant concerns raised in the comments on EPA’s 2014 risk assessment and 2015 proposed revocation that EPA’s assessment fails to protect children. In particular, the Objectors focus on concerns raised in comments asserting that (1) EPA’s use of 10 percemt cholinesterase as a regulatory standard is not protective for effects to children’s developing brains; (2) EPA has not properly accounted for effects from inhalation of chlorpyrifos from spray drift and volatilization; and (3) EPA inappropriately used the Corteva physiologically based pharmacokinetic (PBPK) model to reduce inter- and intra-species safety factors because the model is ethically and scientifically deficient.

• EPA Response:  EPA denies the objections claiming procedural error, stating it “has no obligation to respond to rulemaking comments in denying the Petition or responding to objections, both of which are adjudicatory actions that are not part of the rulemaking process.  EPA also restated its prior response to the Petition that the “objections fail to meet burden of presenting evidence sufficiently valid, complete and reliable to demonstrate that chlorpyrifos results in neurodevelopmental effects that render its tolerances not safe.”  EPA further “believes it is lawful and appropriate for it to consider federally enforceable chlorpyrifos product labeling restrictions in assessing the extent of bystander risk from spray drift under both the FFDCA and FIFRA.”

Commentary

This latest EPA assessment appears to be more finely crafted than the earlier March 2017 response to the tolerance revocation Petition.  EPA explains that it does not consider the epidemiology studies cited by the Petitioners to be persuasive sufficiently to change EPA’s fundamental approach to assessing chlorpyrifos risks.  EPA notes that its current risk assessment utilizes the default 10X safety factor for infants and children specified by the FQPA, so any argument that it has not utilized this safety factor is moot.  At the same time, EPA maintains that the epidemiology studies do not justify changing EPA’s point of departure for risk assessment, which remains the threshold for 10 percent acetylcholinesterase (AChE) inhibition.  EPA states that there are significant problems with using the epidemiology studies for risk assessment, including lack of access to the underlying data, the absence of any known mechanism for neurodevelopmental effects below the threshold for AChE inhibition, and a lack of scientific consensus on a method for choosing an alternate point of departure based on the epidemiology studies.  This interpretation of the epidemiology studies for chlorpyrifos will remain controversial and these studies will continue to be cited by those who seek to eliminate chlorpyrifos use.

EPA has also taken a position that the burden is on the Petitioners to support a petition to revoke tolerances with reliable data.  What is less clear is “how much” evidence EPA considers sufficient to meet the threshold for tolerance revocation.  Meanwhile, EPA will defer its assessment of possible neurodevelopmental effects of chlorpyrifos below the threshold for AChE inhibition pending completion of the registration review for chlorpyrifos.  The deadline for EPA to complete registration review is October 1, 2022, although EPA states that it intends to expedite this process and to issue a proposed registration review decision by October 2020.

EPA also has included in its decision an intriguing discussion of some new animal studies for chlorpyrifos that purport to show low-level neurodevelopmental effects from chlorpyrifos.  The California Department of Pesticide Regulation relied substantially on these new studies when it designated chlorpyrifos as a Toxic Air Contaminant.  If these new chlorpyrifos studies are deemed credible, they could supplant efforts to use the chlorpyrifos epidemiology data in risk assessments and allow EPA to establish a new point of departure for chlorpyrifos that is not based on AChE inhibition.  Rather than disregarding these new data, which were not submitted in support of the tolerance revocation Petition, EPA says affirmatively that it intends to review them in the pending registration review.

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By Lisa M. Campbell and Barbara Christianson

On June 26, 2019, the U.S. Environmental Protection Agency (EPA) announced it was extending the comment deadline on its Proposed Interim Registration Review Decision (PID) for glyphosate acid and its various salt forms.  84 Fed. Reg. 30112.  EPA states that it is extending the comment deadline “after receiving public comments requesting additional time to review the Glyphosate Proposed Interim Registration Review Decision and supporting materials.”

The deadline to submit comments was extended from July 5, 2019, to September 3, 2019.  The public can submit comments on EPA’s proposed decision at www.regulations.gov in Docket Number EPA-HQ-OPP-2009-0361.

More information on glyphosate issues is available on our blog.

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By Lisa M. Campbell, Lisa R. Burchi, and James V. Aidala

On May 6, 2019, the U.S. Environmental Protection Agency (EPA) announced it was releasing its Proposed Interim Registration Review Decision (PID) for glyphosate acid and its various salt forms.  84 Fed. Reg. 19782.  In the PID, EPA states that it “did not identify any human health risks from exposure to any use of glyphosate” but did identify “potential risk to mammals and birds” within the application area or areas near the application area and “potential risk to terrestrial and aquatic plants from off-site spray drift, consistent with glyphosate’s use as a herbicide.”  Even with these potential risks, the PID states that “EPA concludes that the benefits outweigh the potential ecological risks when glyphosate is used according to label directions” and proposes certain risk mitigation strategies, including:

• “To reduce off-site spray drift to non-target organisms, the EPA is proposing certain spray drift management measures” with specific spray drift mitigation language to be included on all glyphosate product labels for products applied by liquid spray application;
• “To preserve glyphosate as a viable tool for growers and combat weed resistance, the EPA is … proposing that herbicide resistance management language be added to all glyphosate labels” and to require measures “for the pesticide registrants to provide growers and users with detailed information and recommendations to slow the development and spread of herbicide resistant weeds”;
• Inclusion on labels of a non-target organism advisory statement to alert users of potential impact to non-target organisms; and
• “EPA is also proposing certain labeling clean-up/consistency efforts to bring all glyphosate labels up to modern standards.”

EPA states that these measures were discussed with glyphosate registrants, who do not oppose the proposed risk mitigation measures outlined in the PID.

The public can submit comments on EPA’s proposed decision at www.regulations.gov in Docket Number EPA-HQ-OPP-2009-0361.  Public comments are due by July 5, 2019.  In addition to the PID, EPA is also posting to the glyphosate docket EPA’s response to comments on glyphosate’s usage and benefits (dated April 18, 2019), EPA’s response to comments on the human health risk assessment (dated April 23, 2018), and EPA’s response to comments on the preliminary ecological risk assessment (dated November 21, 2018). 

This PID was issued shortly after the Agency for Toxic Substances and Disease Registry’s announcement on April 8, 2019, of the opening of a docket on the draft toxicological profile for glyphosate.  84 Fed. Reg. 13922.  ATSDR seeks comments and additional information or reports on studies about the health effects of glyphosate for review and potential inclusion in the profile.  Comments are due by July 8, 2019.

Commentary

EPA’s PID and related documents, along with ATSDR’s draft profile and the peer review which will follow, can be expected to become part of the larger debate about the potential risks of glyphosate.  In 2017, EPA evaluated the carcinogenic risk of glyphosate, and released its draft human health and ecological risk assessments.  See our December 19, 2017, blog item "EPA Releases Draft Human Health and Ecological Risk Assessments for Glyphosate for Public Comment" for more information. 

EPA’s PID is interesting not only for the conclusions EPA reached following its review of data submitted by registrants in response to a data call-in (DCI) and following the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Scientific Advisory Panel’s (SAP) meeting to consider and review scientific issues related to EPA’s evaluation of the carcinogenic potential of glyphosate, but for the issues that remain to be addressed.  Notably, EPA states that it has not considered the petition filed on September 27, 2018, to reduce glyphosate’s tolerance because the petition was filed after the comment period for the human health and ecological risk assessments closed.  Instead, EPA plans to post the petition in the glyphosate docket and address the petition concurrently with the development of the Interim Registration Review Decision.

In addition, EPA has not in the PID or related documents addressed issues regarding its Endangered Species Act (ESA) assessment or its Endocrine Disruptor Screening Program (EDSP) activities.  EPA states it intends to complete an assessment of risk to ESA-listed species prior to completing its final registration review decision for glyphosate, and that it also will make an EDSP determination under Federal Food, Drug, and Cosmetic Act (FFDCA) Section 408(p) before completing its registration review.  EPA also notes that it continues to evaluate risks to pollinators, and that if it determines “that additional pollinator exposure and effects data are necessary to help make a final registration review decision for glyphosate, then the EPA will issue a DCI to obtain these data.”  Although there are significant areas that remain to be resolved, EPA issued the PID “so that it can (1) move forward with aspects of the registration review case that are complete and (2) implement interim risk mitigation.”

More information on glyphosate issues is available on our blog.

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