By James V. Aidala and Dennis R. Deziel

The U.S. Environmental Protection Agency (EPA) announced on August 18, 2022, it released its draft ecological risk assessment for dicamba for a 60-day public review. 87 Fed. Reg. 50854. The 287-page assessment examines the potential ecological risks associated with currently registered uses of dicamba on non-target, non-listed species. Risks to federally listed threatened and endangered species are not evaluated in the assessment. EPA is reevaluating the risks of dicamba as part of a routine review process for pesticides that occurs every 15 years. Comments are due October 17, 2022. EPA expects to propose an interim decision regarding the reregistration of dicamba in 2023.

Dicamba is a systemic benzoic acid used primarily to control annual, biennial, and perennial broadleaf weeds. First registered in the United States in 1967, it is currently registered for use on a wide variety of agricultural crops, such as soybeans, cotton, corn, grains, and sorghum, as well as for non-agricultural uses, such as rangeland, fallow fields, turf, and residential premises.

The draft assessment focuses on areas where there have been updates since the most recent national-level risk assessments of dicamba by EPA (2005 and 2020) to examine if the risk picture has changed based on new data and analysis. The 2005 risk assessment was for dicamba’s Registration Eligibility Decision (RED) based on use patterns registered at that time, which were applications to non-dicamba-tolerant plants. The 2020 risk assessment was exclusively to evaluate risk associated with relatively new uses of applications to dicamba-tolerant plants (i.e., soybeans and cotton).

In general, the risk conclusions of the draft assessment are consistent with those identified in past national-level risk assessments for dicamba with a few notable exceptions:

• Lower Risks to Birds. The risk assessment incorporates recently submitted toxicity data (chronic toxicity to birds), information that eases previously identified chronic risk concern for birds in dicamba-tolerant plants.
• New Risks to Bees. Recently submitted toxicity data indicate a previously unidentified potential chronic risk concern for honeybees from all uses on non-dicamba-tolerant plants. EPA used application rates higher than those EPA evaluated in its 2020 assessment, and potential chronic risks to bees are based on weight-of-evidence and maximum single application rates. The uses with the greatest potential chronic bee risks are asparagus, soybean, dicamba-tolerant cotton, and any registered uses on unmaintained non-agricultural areas.
• Risks to Fish. Updated exposure estimates accounting for the combined residues of dicamba indicate a previously unidentified potential chronic risk concern for non-listed fish. Updated exposure estimates accounting for the combined residues of dicamba (dichlorosalicylic acid (DCSA) and 6-CSA, degradates of dicamba) indicate a previously unidentified potential chronic risk concern for non-listed fish from one use scenario.

Also of significance, there are thousands of reported incidents allegedly caused by dicamba exposure occurring at or near a wide variety of agricultural and non-agricultural use sites and affecting a wide variety of plant species. According to EPA, a pronounced increase in the overall number of reported dicamba incidents associated with damage to non-target plants started around 2016 and appears to link to the introduction of dicamba-tolerant plants and “over-the-top” (OTT) applications to those crops. The combined evidence from field studies and incident data indicates that there may be off-site movement of dicamba via runoff, spray drift, and volatility from the use of dicamba, particularly for OTT application on dicamba-tolerant plants.

Damage to plant species near areas of application presents two separate issues of concern that will have to be addressed in EPA’s eventual decisions:

1. Does routine OTT use of dicamba cause unacceptable damage to nearby commercial crops? and
2. Does any tendency to injure nearby plants represent a possible concern about possible impacts on threatened and endangered species when EPA eventually includes Endangered Species Act (ESA) assessments as part of its review?

In 2020, EPA concluded that its 2020 label restrictions of dicamba-tolerant plants would significantly reduce incident reports about damage to nearby crops. Despite the new control measures, EPA received nearly 3,500 incident reports for the 2021 growing season of damage to non-dicamba-tolerant soybean, numerous other crops, and a wide variety of non-target plants in non-crop areas, including residences, parks, and wildlife refuges. EPA continues to monitor and evaluate new incident report submissions, and the analysis will be updated as new information becomes available. Dicamba also continues to be an important issue of discussion at State FIFRA [Federal Insecticide, Fungicide, and Rodenticide Act] Issues Research and Evaluation Group (SFIREG) meetings where data, analysis, and recommendations for dicamba continue to be discussed.

Commentary

This is the first time dicamba has been identified to pose risks to bees and fish. Worth noting, the identified chronic risks to honeybees, which could indicate that dicamba affects the larvae stage as well as the adult stage of bees, in a time of increased attention to bee health, throws dicamba into another arena of controversy previously unidentified and could garner significant attention in the environmental community, industry, and EPA.

Still, the most significant risk continues to be to possible impacts on non-target terrestrial plants from spray drift and volatilization. Almost 3,500 incident reports for a single growing season are hard to ignore. EPA has received numerous complaints about dicamba damaging non-target plants since EPA allowed the herbicide OTT application on genetically modified soybeans and cotton in 2016. Spraying dicamba over the top of crops after they have emerged is typically done later in the growing season, when temperatures are hotter and other crops/plants are maturing in nearby areas. In warmer temperatures, the herbicide is more likely to volatilize from target application areas and drift, also because of the warmer temperatures. Environmental groups sued EPA to halt the approval, and a federal appeals court ordered EPA in June 2020 to cancel all registrations for use on dicamba-tolerant crops.

In October 2020, EPA issued new registrations with new controls intended to reduce and prevent dicamba movement from volatilizing and drifting onto neighboring properties. Based on the most recent incident reporting, however, the measures did not stop the complaints about harm to nearby crops, plants, and trees.

This draft ecological risk assessment puts dicamba under scrutiny once again and may signal important registration challenges for the herbicide in 2023.

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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 Carla N. Hutton

The European Chemicals Agency (ECHA) and the European Food Safety Authority (EFSA) have received a draft assessment of glyphosate carried out by four European Union (EU) member states and have begun to consider the findings. According to ECHA’s June 15, 2021, press release, the national authorities of France, Hungary, the Netherlands, and Sweden -- known as the Assessment Group of Glyphosate (AGG) -- examined all the evidence submitted by the companies that are seeking renewed approval to market the glyphosate in the EU. Glyphosate is currently authorized for use in the EU until December 2022.

ECHA and EFSA will organize parallel consultations on the draft report. These will be open to the public and will be held in the first week of September 2021. According to ECHA, the consultations are the first step in the assessments. ECHA’s Committee for Risk Assessment (RAC) will review the classification of glyphosate under the Classification, Labeling and Packaging (CLP) Regulation. ECHA notes that chemical classification is based solely on the hazardous properties of a substance and does not consider the likelihood of exposure. Exposure is considered as part of the risk assessment process led by EFSA.

Glyphosate currently has a harmonized classification as causing serious eye damage and as toxic to aquatic life with long-lasting effects, prior to and following ECHA’s 2017 assessment. ECHA states that no classification for germ cell mutagenicity, carcinogenicity, or reproductive toxicity was warranted. The AGG proposal does not foresee a change to the existing classification.

Once ECHA adopts its opinion on the classification of glyphosate, EFSA will prepare a final peer review and publish its conclusions, expected in late 2022. Based on this risk assessment, the European Commission (EC) will decide whether to renew glyphosate.

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By Carla N. Hutton

The European Food Safety Authority (EFSA) announced on March 15, 2021, that it has begun a public consultation on a draft updated Guidance on the assessment of exposure of operators, workers, residents, and bystanders in risk assessment for plant protection products (PPP).  According to EFSA, the Guidance is designed to assist risk assessors and applicants when quantifying potential non-dietary, systemic exposures as part of the regulatory risk assessment for PPPs.  The Guidance is based on the Scientific Opinion on “Preparation of a Guidance Document on Pesticide Exposure Assessment for Workers, Operators, Residents and Bystanders” developed by the EFSA Panel on Plant Protection Products and their Residues (PPR) in 2010.  EFSA states that highlighting some inconsistencies between the approaches adopted by regulatory authorities, the PPR Panel proposed a number of changes to the practices in use (i.e., use of deterministic methods for individual PPPs; need to perform an acute risk assessment for PPPs that are acutely toxic; use of appropriate percentile for acute or longer term risk assessments).  In the first version of the Guidance, issued in 2014, EFSA included several scenarios for outdoor uses, with an annexed calculator, as well as recommendations for further research.  EFSA has updated the Guidance in 2021 to include additional scenarios and revise default values on the basis of the evaluation of additional evidence.  To support users in performing the assessment of exposure and risk, EFSA further developed an online calculator that reflects the Guidance content.  Comments on the draft updated Guidance are due May 9, 2021.  EFSA will assess all comments submitted in line with the specified criteria.  The relevant EFSA Panel will further consider the comments and take them into consideration if found to be relevant.

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By Lynn L. Bergeson and Carla N. Hutton

On February 1, 2021, the U.S. District Court for the District of Montana granted the U.S. Environmental Protection Agency’s (EPA) January 31, 2021, unopposed motion to vacate and remand its January 6, 2021, final rule on “Strengthening Transparency in Pivotal Science Underlying Significant Regulatory Actions and Influential Scientific Information” (86 Fed. Reg. 469).  EDF v. EPA, No. 4:21-cv-03-BMM.  On January 11, 2021, the Environmental Defense Fund (EDF), Montana Environmental Information Center (MEIC), and Citizens for Clean Energy (CCE) filed suit against EPA, claiming that the January 6, 2021, final rule was unlawful and that EPA’s decision to make the final rule effective on publication was unlawful.  On January 27, 2021, the court granted summary judgment to the plaintiffs, finding that EPA did not provide good cause to exempt the final rule from the Administrative Procedure Act’s (APA) 30-day notice requirement.  The court stated that “EPA’s decision to make the Final Rule immediately effective on publication was ‘arbitrary, capricious’ and ‘otherwise not in accordance with law.’”  In its January 31, 2021, motion, EPA states based on the court’s conclusion that the final rule constitutes a substantive rule and that EPA “lacked authorization to promulgate the rule pursuant to its housekeeping authority.”  According to EPA, where EPA lacked the authority to promulgate the final rule, “remand without vacatur would serve no useful purpose because EPA would not be able to cure that defect on remand.”  EPA notes that because the final rule was in effect for less than a month, and it had not applied the rule in any circumstance while the rule was in effect, “there would be no disruptive consequences in remanding and vacating the rule.”

Prior to EPA’s motion to vacate and remand the final rule, on January 20, 2021, President Joe Biden signed an Executive Order (EO) on Protecting Public Health and the Environment and Restoring Science to Tackle the Climate Crisis.  According to the EO, it is the policy of the Biden Administration “to listen to the science; to improve public health and protect our environment; to ensure access to clean air and water; to limit exposure to dangerous chemicals and pesticides; to hold polluters accountable, including those who disproportionately harm communities of color and low-income communities; to reduce greenhouse gas emissions; to bolster resilience to the impacts of climate change; to restore and expand our national treasures and monuments; and to prioritize both environmental justice and the creation of the well-paying union jobs necessary to deliver on these goals.”  The EO directs all executive departments and agencies to review immediately and, as appropriate and consistent with applicable law, take action to address the promulgation of federal regulations and other actions during the Trump Administration that conflict with the Biden Administration’s national objectives, and to commence work immediately to confront the climate crisis.  The EO calls for the heads of all agencies to review immediately “all existing regulations, orders, guidance documents, policies, and any other similar agency actions (agency actions) promulgated, issued, or adopted between January 20, 2017, and January 20, 2021, that are or may be inconsistent with, or present obstacles to,” the Biden Administration’s policy.  For any identified actions, the EO directs the heads of agencies to “consider suspending, revising, or rescinding the agency actions.”  In addition, for certain specified agency actions, the EO states that the head of the relevant agency “shall consider publishing for notice and comment a proposed rule suspending, revising, or rescinding the agency action within the time frame specified.”  The specified agency actions include EPA’s January 6, 2021, final rule on “Strengthening Transparency in Pivotal Science Underlying Significant Regulatory Actions and Influential Scientific Information.”

As reported in our January 11, 2021, memorandum, the origin of EPA’s January 6, 2021, final rule is rooted in legislative proposals more clearly intended to challenge important regulatory requirements, particularly related to EPA’s air program.  We predicted that the final rule would likely be among the first items subject to reversal or “clarifying” guidance making it consistent with previously established science policies (see Bergeson & Campbell, P.C.’s (B&C®) Forecast 2021 memo).  With Democratic control of both houses of Congress, there might also be attempts to repeal the rule via action under the Congressional Review Act (CRA) of recently promulgated regulations.

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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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This week's All Things Chemical™ Podcast will be of interest to readers of the Pesticide Law & Policy Blog^®. A brief description of the episode written by Lynn L. Bergeson is below.

This week I sat down with James Aidala, B&C’s Senior Government Affairs Consultant, to catch up on what the U.S. Environmental Protection Agency’s (EPA) Office of Pesticide Programs (OPP) is up to and to get a sense of what we might expect to develop over the remainder of the year.  As a former Assistant Administrator of what is now the Office of Chemical Safety and Pollution Prevention, Jim’s thoughts and analyses are always spot on.

We discuss leadership within OPP, which is transitioning.  Not surprisingly, who holds the position of Office Director is always of great interest to the agricultural and biocidal chemical communities.

We also touch upon a number of high-profile pesticide science policy debates about substances, some of which have been raging literally for years.  These substances include dicamba, glyphosate, and chlorpyrifos.  The legal and scientific administrative and judicial reviews under way in the United States and internationally are fascinating, precedent setting, and closely watched.

Our conversation also includes a bit about the commercial agricultural chemical community.  Industry consolidation and international trade issues continue to challenge the commercial landscape, and they make keeping up with these issues all the more important.

ALL MATERIALS IN THIS PODCAST ARE PROVIDED SOLELY FOR INFORMATIONAL  AND ENTERTAINMENT PURPOSES. THE MATERIALS ARE NOT INTENDED TO CONSTITUTE LEGAL ADVICE OR THE PROVISION OF LEGAL SERVICES. ALL LEGAL QUESTIONS SHOULD BE ANSWERED DIRECTLY BY A LICENSED ATTORNEY PRACTICING IN THE APPLICABLE AREA OF LAW.

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

In September 2020, the U.S. Environmental Protection Agency’s (EPA) Office of Pesticide Programs (OPP) plans to convene a Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) Scientific Advisory Panel (SAP) meeting to discuss New Approach Methodologies (NAM) for organophosphate (OP) pesticides.  EPA states that these NAMs could reduce reliance on default uncertainty factors for human health risk assessment and also reduce animal testing.

Under Administrator Wheeler’s directive to prioritize efforts to reduce animal testing, EPA is developing NAMs based on in vitro techniques and computational approaches that will also provide the opportunity to incorporate information relevant to humans.  OPP states that it is evaluating use of “in vitro data for 16 organophosphate compounds to reduce potentially reliance on default risk assessment uncertainty factors in favor of more refined data-derived factors.”  Human health risk assessment for OP pesticides has recently been focused primarily on potential developmental neurotoxicity, and the Office of Research and Development (ORD) has been working to develop a NAM to evaluate developmental neurotoxicity.  Initial analyses of data derived from neuron cell models have been completed for specific OP pesticides as a case study and, when possible, compared to in vivo results (an in vitro to in vivo extrapolation).

This case study of a NAM for developmental neurotoxicity using OP pesticides will be presented to the FIFRA SAP at the September meeting for its consideration and advice.  EPA will request external review and public comment on this research before implementing NAMs in human health risk assessments.  Additional details, including dates, times and agenda, will be forthcoming at www.epa.gov/sap.

Commentary

EPA has for some time had a general policy that it will try to develop and to implement alternatives to in vivo animal testing.  These alternatives to animal testing are typically based on new in vitro assays and modeling methodologies.  It is interesting that OPP has selected an in vitro NAM to assess developmental neurotoxicity of OP pesticides as a case study, given the controversy surrounding EPA’s use of the default Food Quality Protection Act (FQPA) uncertainty factor for all OP pesticides, which was based primarily on epidemiology data that EPA claimed may suggest a link between chlorpyrifos exposure and developmental neurotoxicity.  Prior to this determination, human health risk assessment for OP pesticides was generally based on expert judgments by EPA that neurotoxicity would not be expected below the established threshold for acetylcholinesterase (AChE) inhibition, and that infants and children are not likely to be more sensitive to neurotoxic effects than adults.  OPP adopted the FQPA determination for all OP pesticides even though it could not determine or propose a mechanism for the presumed developmental neurotoxicity of chlorpyrifos below the threshold for AChE inhibition, or evaluate whether other OP pesticides might share a similar mechanism.  Since the 2015 release of the Literature Review, additional epidemiology studies have become available and a number of concerns regarding the reliability of the epidemiology data have been raised.  EPA has also expressed concerns with the availability and reliability of the epidemiology studies.  These developments bring into question the accuracy and reliability of the Literature Review.

In its announcement, OPP states that the new NAM is intended “to reduce potentially reliance on default risk assessment uncertainty factors,” although it does not state which uncertainty factors may be supplanted or modified.  Standard uncertainty factors which may be implicated include the factor for extrapolating from animal data to human effects (“interspecies variation”), the factor for human variability (“intraspecies variation”), and the default uncertainty factor for potential increased sensitivity of infants and children (“FQPA uncertainty factor”).  The issues may spark additional controversy.  Additionally, even if OPP and the FIFRA SAP conclude that the proposed NAM for developmental neurotoxicity is a viable approach to human health risk assessment for OP pesticides, there are likely to be many related policy issues.  For example, it is unclear whether OPP would be sufficiently confident in the reliability of such an assay to propose cancellation or suspension of affected pesticide products based on a resultant human health risk assessment.

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By Timothy D. Backstrom and Kelly N. Garson

On December 6, 2019, the European Union (EU) announced that it will no longer permit sales of chlorpyrifos after January 31, 2020.  The Standing Committee on Plants, Animals, Food and Feed (PAFF Committee) voted in favor of two draft Implementing Regulations that denied the renewal of approvals for chlorpyrifos and chlorpyrifos-methyl.  The European Commission is expected to formally adopt the regulations in January 2020.  At that time, Member States will need to withdraw authorizations for products containing chlorpyrifos and chlorpyrifos-methyl as active substances and may implement a grace period, at a maximum of three months, for final storage, disposal, and use of the substances.

The ban in the EU follows increased concerns over the human health effects of the substances.  On August 2, 2019, the European Food Safety Authority (EFSA) published a report concluding that no safe exposure level could be determined for chlorpyrifos and that based upon available data, the approval criteria under Article 4 of Regulation (EC) No 1107/2009 for human health were not met.  EFSA also published an updated statement reiterating the same conclusion for chlorpyrifos-methyl on November 26, 2019.  EFSA’s primary health concerns were potential developmental neurotoxicity based on the available animal data and epidemiological evidence, and unresolved concerns regarding potential genotoxicity.  EFSA also concluded that toxicological reference values could not be established for either of these effects, thereby precluding a valid risk assessment for consumers, workers, or bystanders.

Prior to the PAFF Committee meeting, eight EU states had already banned or never approved the use of chlorpyrifos.  Canada proposed a ban of chlorpyrifos on May 31, 2019.  (More information on this proposal is available in our blog post).

Within the United States, state governments have taken steps to regulate chlorpyrifos.  On June 13, 2018, Hawaii passed an act that banned the use of pesticides containing chlorpyrifos as an active ingredient beginning January 1, 2019.

Several recent actions in California culminated in a ban on chlorpyrifos.  First, the California Department of Pesticide Regulation (DPR) decided that chlorpyrifos should be designated as a Toxic Air Contaminant.  This action was based primarily on a point of departure derived from new animal studies that report neurodevelopmental effects well below the level that inhibits cholinesterase.  On August 14, 2019, DPR issued cancellation notices for chlorpyrifos products based primarily on the same new animal data.  DPR subsequently announced on October 9, 2019, an agreement with pesticide manufacturers to end the sale of chlorpyrifos by February 6, 2020.  Growers will not be able to possess or use chlorpyrifos products in the state after December 31, 2020.

In New York State (NYS), recent efforts to ban the substance through legislation were unsuccessful.  On December 10, 2019, NYS Governor Andrew Cuomo vetoed a bill passed by the NYS Legislature (A.2477/S.5343) to phase out chlorpyrifos from use by December 1, 2021.  Governor Cuomo stated that the NYS Department of Environmental Conservation is responsible for taking regulatory action on the issue, but recommended that the agency implement its own phased-in ban of chlorpyrifos.

On the federal level, chlorpyrifos products remain registered and have been since 1965.  The U.S. Environmental Protection Agency (EPA) has taken measures to restrict the use of chlorpyrifos within households and on particular crops, but some non-governmental organizations (NGO) have long advocated that chlorpyrifos should be banned in its entirety.  On September 12, 2007, the Pesticide Action Network North America (PANNA) and the Natural Resources Defense Council (NRDC) filed a petition requesting that EPA revoke all tolerances and cancel all registrations for chlorpyrifos.  EPA’s failure to respond fully to this petition was the subject of several decisions in the 9th Circuit Court of Appeals, and the Court ultimately issued a writ of mandamus requiring that EPA take final action concerning the petition.

At one point, EPA proposed to revoke all tolerances for chlorpyrifos.  This action was based in part on a controversial determination that EPA should reinstate the default safety factor for tolerance assessments under the Food Quality Protection Act (FQPA) for all organophosphate (OP) pesticides.  This determination was based on developmental neurotoxicity associated with chlorpyrifos exposure in certain epidemiology studies.  After further deliberation and a change of administrations, EPA issued an order denying the 2007 petition in its entirety on March 29, 2017, based in part on a conclusion stating that further evaluation was needed to properly assess potential neurodevelopmental effects of chlorpyrifos.  EPA later issued a final order that denied all objections to the March 2017 petition denial order.  A number of NGOs (including the original petitioners) and several states have challenged this decision, filing petitions on August 8 and August 9, 2019, respectively for judicial review of EPA’s final order retaining tolerances and registrations for chlorpyrifos.  EPA has stated that it intends to complete its evaluation of the epidemiology studies for chlorpyrifos, as well as the new animal data relied on by California, in the context of the pending registration review of chlorpyrifos under Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Section 3(g).  A final registration review decision concerning chlorpyrifos is due by October 1, 2022, although EPA has stated that it intends to accelerate that process.  More information on the petitions and chlorpyrifos is available on our blog.

Commentary

At this juncture, the long-term impact of the gradual accumulation of adverse decisions on chlorpyrifos from EFSA and various other governmental agencies is uncertain.  Most user groups in the United States continue to describe chlorpyrifos as an essential agricultural tool.  Some commodities treated with chlorpyrifos are destined for export markets where chlorpyrifos has been banned, however, and the impacts of this change will need to be monitored closely.

EPA’s interpretation of the epidemiology studies for chlorpyrifos remains controversial in the scientific community.  Indeed, although the EFSA conclusion is predicated in part on these epidemiology studies that are the basis of the controversial EPA interpretation, the wording of the EFSA report indicates that there were some dissenters.  Moreover, the extension of EPA’s FQPA determination for chlorpyrifos to other organophosphate (OP) pesticides has never been satisfactorily explained.

The NGOs and states that have challenged EPA’s final order refusing to revoke the tolerances and cancel the registrations for chlorpyrifos will argue that the final order cannot be reconciled with EPA’s prior scientific determinations.  Even if EPA can successfully rebut those arguments, there is also a possibility that EPA’s own review of the new animal chlorpyrifos studies may obviate that controversy.  On balance, the remaining manufacturers and registrations for chlorpyrifos are likely to confront a variety of challenges in the coming months.

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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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