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

By 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.


 

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

On February 6, 2020, Corteva Agriscience (Corteva), announced it will discontinue all production of the organophosphate (OP) insecticide chlorpyrifos by the end of the year.  Corteva and its corporate predecessor, Dow AgroSciences, have been the principal global manufacturers of chlorpyrifos.  Corteva announced that its decision to stop selling chlorpyrifos was based entirely on financial considerations.  This announcement came on the same day that Corteva had previously agreed it would end further sales of chlorpyrifos in California, and less than a week after the date the European Union (EU) ended all sales of chlorpyrifos in member states.  These actions followed a number of prior actions taken by other national and state governments to ban or severely restrict chlorpyrifos.  Corteva emphasized in its public statements that the science demonstrates that chlorpyrifos can be safely used, but that the company made a business decision based on the declining markets for the product.  In an interview reported by the Washington Post, Susanne Wasson, Corteva's President for Crop Protection said, “It’s a tough decision for us to make, but we don’t feel like it’s viable going forward.” In other statements, Corteva noted that in the last ten years their share of the global chlorpyrifos market had declined from 75% to less than 20%.

Chlorpyrifos has been registered for use in the U.S. for over 50 years, but has become increasingly controversial in the dozen years since the Pesticide Action Network of North America and the Natural Resources Defense Council filed a petition in 2007 to cancel all registrations and revoke all tolerances for chlorpyrifos.  Following a protracted court battle and a decision by the Ninth Circuit Court of Appeals to force the U.S. Environmental Protection Agency (EPA) to take final administrative action concerning the 2007 petition, EPA proposed near the end of the Obama Administration to revoke all existing tolerances for chlorpyrifos.  A significant basis for this proposal was a controversial decision by a panel of EPA scientists that the default tenfold safety factor established by the Food Quality Protection Act (FQPA) for infants and children, which EPA had previously waived based on studies establishing a threshold for acetylcholinesterase (AChE) inhibition, should be reinstated.

The new EPA safety factor determination was based in large measure on epidemiology studies that reported an association between exposure to chlorpyrifos at levels below the presumed threshold for AChE inhibition and adverse neurodevelopmental effects in children.  Many industry scientists disputed the scientific basis for this EPA determination because confounding exposures and methodological biases in the epidemiology studies may have influenced the reported association with neurodevelopmental effects and because the EPA determination made unprecedented use of epidemiology data.  Beyond the effect on chlorpyrifos, the EPA decision will likely continue to be controversial because EPA included a similar safety factor determination for all OP pesticides, even though the mechanism responsible for the reported neurodevelopmental effects attributed to chlorpyrifos has not been identified and the other OP products were not studied in the epidemiology studies.

In the first year of the Trump Administration, EPA Administrator Scott Pruitt decided not to adopt EPA’s previously proposed tolerance revocation and instead to deny formally the 2007 petition, citing unresolved scientific issues.  This reversal of course, however, was not accompanied by any new scientific assessment or by any explicit revision of the prior FQPA safety factor determination.  Later, the California Department of Pesticide Regulation (DPR) decided to designate chlorpyrifos as a Toxic Air Contaminant, a decision that was noteworthy because it was based primarily on new toxicology studies that DPR stated reported neurodevelopmental effects well below the threshold for AChE inhibition.  DPR deemphasized the epidemiology data relied on in the EPA safety factor determination in its decision.  Although EPA later stated that it would address these new toxicology studies as part of an accelerated registration review process, there were intervening decisions by the EU and by California to ban new sales, which may have contributed to Corteva’s February 6, 2020, decision to cease chlorpyrifos production.

Commentary

The decision by Corteva to cease manufacturing chlorpyrifos reminds us that the decision to continue marketing any chemical substance cannot be based solely on the scientific data, but must also consider the regulatory climate and the economic viability of the product.  For those of us with a long memory, the decision by Corteva is reminiscent of the decision nearly 40 years ago by the Dow Chemical Company to pull the plug on 2,4,5-T and silvex, after Dow had expended millions of dollars and many years of effort to contest an emergency suspension and subsequent cancellation of these herbicides.  Dow made this decision even though it believed that the available data demonstrated the safety of those products.


 

By Lisa M. Campbell and James V. Aidala

On May 25, 2018, the U.S. Environmental Protection Agency (EPA) issued an extension of the comment period of the proposed rule entitled “Strengthening Transparency in Regulatory Science” (Science Rule) that EPA issued on April 30, 2018.  83 Fed. Reg. 24255.  The Federal Register notice states that EPA will extend the comment period from May 30, 2018, to August 16, 2018.  EPA states that it is making these changes “in response to public requests for an extension of the comment period and for a public hearing.”  It is noteworthy that the extension was issued on the heels of EPA’s receipt of letters, one submitted by eight Attorneys General and another by 20 Senators, addressing the proposal, as described below.  Comments can be filed in Docket ID No. EPA-HQ-OA-2018-0259 on www.regulations.gov

EPA’s notice also announces that it will be holding a public hearing for the proposed rule on July 17, 2018, from 8:00 a.m. to 8:00 p.m. (EDT) in Washington, D.C. that will provide “the public with an opportunity to present oral comments regarding [the Science Rule]”; and will “provide interested parties the opportunity to present data, views, or arguments concerning the proposal.”  The notice states that EPA may ask clarifying questions during the oral presentations, but will not respond to the presentations at that time.  Registration for the public hearing will be available online; registration information is available in the Federal Register notice.

EPA’s extension and its grant of requests for a public hearing follows closely in time of its receipt, on May 7, 2018, of a letter to EPA Administrator Scott Pruitt from eight Attorneys General -- those of New York, California, Delaware, Iowa, Maine, Minnesota, Pennsylvania, and the District of Columbia -- expressing their concern regarding the Science Rule.  The letter requests EPA to withdraw the proposed rule and to consult with the National Academy of Sciences (NAS).  The letter states that if EPA is unwilling to withdraw the rule, then EPA should extend the comment period by at least 150 days to “provide for appropriate consultation with the [NAS],” as “a full six-month comment period … is necessary to provide the public and other stakeholders a meaningful opportunity to evaluate the proposal and its implications for the agency’s ability to meet its obligation to protect public health and the environment under federal environmental laws.” 

On May 14, 2018, 20 Senators submitted a letter to Pruitt requesting that the comment deadline be extended, to July 30, 2018, stating that this extra time would give “stakeholders adequate time to draft and submit thorough, well-reasoned comments,” as the rule is “expected to have a significant effect on the types and number of scientific studies EPA considers during rulemaking” and “implicates patient privacy.”

It is not clear if the extension of time for public comment indicates a desire to develop a more thorough record behind whatever may emerge as the final rule or is a reaction to some of the intense opposition to the entire scheme.  “EPA Science” has been controversial and an emerging political issue for some time, but the reaction to the proposal has been intense even in comparison to many of the changes the Trump Administration has sought to impose on other EPA policies and procedures.  To some degree, if the Trump Administration hopes to change EPA’s fundamental approach to decision-making, the sooner the better for the potential to leave a lasting change in place.  Meanwhile, even from a relatively neutral perspective, the proposal is complicated as to how such new requirements would work -- what it applies to, or how some of the critical new terms would be defined (e.g., “pivotal science”), among other complex elements.  This complexity may be its ultimate undoing, or perhaps careful consideration of voluminous (and much critical) public comment will hone the proposal into something more likely to achieve its stated goals.

More information about the Science Rule is available on our blog and in our memorandum EPA Releases Strengthening Transparency in Regulatory Science Proposed Rule.


 

By Lisa M. Campbell and James V. Aidala

On April 30, 2018, the U.S. Environmental Protection Agency (EPA) will publish in the Federal Register a proposed rule entitled "Strengthening Transparency in Regulatory Science" (Science Rule) that EPA states is intended to “strengthen the transparency of EPA regulatory science.”  EPA states in the preamble that “[t]he proposed regulation provides that when EPA develops regulations, including regulations for which the public is likely to bear the cost of compliance, with regard to those scientific studies that are pivotal to the action being taken, EPA should ensure that the data underlying those are publicly available in a manner sufficient for independent validation.”  EPA further states that “EPA is proposing to establish a clear policy for the transparency of the scientific information used for significant regulations:  specifically, the dose response data and models that underlie what we are calling ‘pivotal regulatory science.’ ‘Pivotal regulatory science’ is the studies, models, and analyses that drive the magnitude of the benefit-cost calculation, the level of a standard, or point-of-departure from which a reference value is calculated.” 

EPA intends the rule to provide this transparency “in a manner consistent with statutory requirements for protection of privacy and confidentiality of research participants, protection of proprietary data and confidential business information, and other compelling interests.”  EPA “will use peer-reviewed information, standardized test methods, consistent data evaluation procedures, and good laboratory practices to ensure transparent, understandable, and reproducible scientific assessments.”  EPA states that its “regulatory science” should be “consistent with the Office Management and Budget’s Final Information Quality Bulletin for Peer Review,” and that “[r]obust peer review plays a critical role in independently validating key findings and ensuring that the quality of published information meets the standards of the scientific and technical community.”  In addition, EPA states, the proposed rule “is designed to increase transparency of the assumptions underlying dose response models,” noting that “[t]he use of default models, without consideration of alternatives or model uncertainty, can obscure the scientific justification for EPA actions.” 

EPA states:  “Across EPA programs much of the science that informs regulatory actions is developed outside the Agency.  It is the charge of regulators to ensure that key findings are valid and credible, as required by OMB’s Guidelines.”  EPA “believes that concerns about access to confidential or private information can, in many cases, be addressed through the application of solutions commonly in use across some parts of the Federal government,” and “[n]othing in the proposed rule compels the disclosure of any confidential or private information in a manner that violates applicable legal and ethical protections.” 

The rule as proposed has ten subparts:

  1. Section 30.1 states the purpose of the rule:  “This subpart directs EPA to ensure that the regulatory science underlying its actions is publicly available in a manner sufficient for independent validation.”
  2. Section 30.2 sets forth definitions of the following five terms:  “dose response data and models”; “pivotal regulatory science”; “regulatory decisions”; “regulatory science”; and “research data.” 
  3. Section 30.3 addresses what and what is not subject to the rule.
  4. Section 30.4 provides:  “EPA shall clearly identify all studies (or other regulatory science) relied upon when it takes any final agency action.  EPA should make all such studies available to the public to the extent practicable.”
  5. Sections 30.5 and 30.6 establish requirements applicable to EPA’s use of dose response data and models underlying pivotal regulatory science, as those terms are defined elsewhere in the proposed rule. 
  6. Section 30.7 requires EPA to conduct independent peer review on all pivotal regulatory science used to justify regulatory decisions, as those terms are defined, and to ask peer reviewers to “articulate the strengths and weaknesses of EPA’s justification for the assumptions applied and the implications of those assumptions for the results.”
  7. Section 30.8 addresses how EPA is to account for cost under the rule.
  8. Section 30.9 provides that EPA may grant an exemption to the rule on a case-by-case basis if EPA “determines that compliance is impracticable” because either:  it is not feasible to ensure that all dose response data and models underlying pivotal regulatory science is publicly available in a manner sufficient for independent validation, in a fashion that is consistent with law, protects privacy, confidentiality, confidential business information, and is sensitive to national and homeland security; or it is not feasible to conduct independent peer review on all pivotal regulatory science used to justify regulatory decisions for reasons outlined in OMB Final Information Quality Bulletin for Peer Review Section IX.​
  9. Section 30.10 addresses other requirements applicable under the rule. 

EPA is soliciting comments on the proposed rule and “how it can best be promulgated and implemented in light of existing law and prior Federal policies that already require increasing public access to data and influential scientific information used to inform federal regulation.”  Among the issues EPA asks for comment are the following:

  1. All aspects of the proposed regulation and the bases articulated for it.
  2. Whether alternative or additional regulatory or other policy vehicles are appropriate to establish and implement these policies, and whether further regulatory or other policy vehicles at the programmatic or statutory level would be appropriate as alternative or additional steps the Agency may take to further the policies articulated.
  3. Effects of the proposed rule on individual EPA programs, including whether certain activities are appropriate to be excepted or if other requirements would affect implementation.
  4. Which criteria the Agency should use to base ay exceptions, including whether case-by-case exceptions may be appropriate.
  5. Whether and to what extent the rule requirements, or other provisions and policies, should apply to other stages of the rulemaking process, including proposed rules, as well as to other types of Agency actions and promulgations, such as guidance.
  6. Whether a narrower scope of coverage would be appropriate, such as only final regulations that are determined to be “major” under the Congressional Review Act, or “economically significant “under EO 12866.
  7. Whether certain categories of regulations should be excluded from coverage, such as those that merely reaffirm an existing standard, or some other category, including whether the rule should apply to individual party adjudications, enforcement activities, or permit proceedings when EPA determines that these provisions are practical and appropriate and that the actions are scientifically or technical novel or likely to have precedent-setting influence on future actions, and whether the Agency should apply the provisions of the proposed rule to these actions or to specific types of actions within these categories.
  8. Whether other agency actions, beyond significant final regulatory actions under EO 12866, should be included, such as site-specific permitting actions or non-binding regulatory determinations.
  9. The definitions of “pivotal regulatory science,” and “dose response data and models” and how to implement such definitions.
  10. How to incorporate stronger data and model access requirements into the terms and conditions of cooperative agreements and grants.
  11. How EPA can build up on other federal agencies’ policies regarding grantee and cooperator requirements for data access and data sharing.
  12. Methodologies and technologies designed to provide protected access to identifiable and sensitive data, such as individual health data, and on commenters’ experience with the use of such methodologies and technologies and their strengths and limitations.
  13. How to balance appropriate protection for copyrighted or confidential business information, including where protected by law, with requirements for increased transparency of pivotal regulatory science.
  14. Whether there are other compelling interests besides privacy, confidentiality, national and homeland security that may require special consideration when data are being released.
  15. Implementation of the proposed regulation, including which parts of the Agency should be responsible for carrying out these requirements.
  16. The effective date of the rule and whether there should be a phase-in, as well as the manner in which the rule should apply to previous records.
  17. Whether and how the proposed rule should apply to dose response data and models underlying pivotal regulatory science if those data and models were developed prior to the effective date.
  18. How the prospective or retrospective application of the provisions for dose response data and models or pivotal regulatory science could inadvertently introduce bias regarding the timeliness and quality of the scientific information available.
  19. How to address a circumstance in which EPA has a statutory requirement to make a determination for which scientific information publicly available in a manner sufficient for independent validation does not exist
  20. Additional implementation challenges not discussed in the notice.
  21. Whether proposed exemptions are appropriate.
  22. Whether disclosure requirements applicable to dose response data and models in the proposed rule should be expanded to cover other types of data and information, such as economic and environmental impact data and models that are designed to predict the costs, benefits, market impacts and/or environmental effects of specific regulatory interventions on complex economic or environmental systems. 

On April 26, 2018, EPA Administrator Scott Pruitt was a witness in a hearing before the U.S. House Committee on Energy and Commerce, Subcommittee on Environment entitled The Fiscal Year (FY) 2019 U.S. Environmental Protection Agency (EPA) Budget.  Administrator Pruitt discussed the forthcoming proposed rule at this hearing, stating that the rule is an effort to make the data and methodology that underlie scientific studies, oftentimes done by third parties, more accessible and more transparent -- especially to those interested stakeholders commenting on the determinations that the studies support.  Many of the Committee members were supportive of the Science Rule, stating that the transparency is long overdue.  Others expressed concerns with the proposed rule, including concerns about a potential for EPA to handpick certain “public” studies and to discount other valid studies only because they did not divulge all of their confidential data; and concerns regarding the inability to protect important confidential information, such as identities of patients. 

Commentary

The proposed rule is controversial and will likely be the subject of significant comment.  Similar to when legislative proposals offer new terminology, the establishment and use of terms such as “pivotal regulatory science” suggest some distinction between it and “not so pivotal science” not subject to the new procedures and requirements.  How such distinctions will be made and what the impact may be could be significant for companies that submit “routine” data under existing Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) regulations concerning registration data requirements. Interest in the subject has been reported to focus especially on questions some have raised about the way EPA has utilized studies and scientific data to support initiatives and rules issued by the air program.  What that raises is a fear that addressing some concerns about how air regulations are justified might have unintended consequences in other EPA media programs.

In brief, for pesticide registrants, the rule poses significant potential issues.  For example, registrants spending millions of dollars on studies necessary to register products that are proprietary and protected from release to those who might use them to register their own products without compensating the owners; issues with regard to EPA’s reliance under the proposed rule on these registrant generated and FIFRA required studies will need to be carefully considered carefully.  As another example, EPA’s review of epidemiology data underlying its conclusions regarding chlorpyrifos and other organophosphate pesticide requirements potentially may be subject to more stringent requirements than they previously were.  Registrants should review the proposed rule carefully and monitor closely developments relating to it.


 

By Carla N. Hutton

On April 10, 2018, the U.S. Environmental Protection Agency (EPA) announced the availability of a draft Science Policy document intended to reduce the use of animals in testing chemicals to evaluate whether they cause an allergic reaction, inflammation, or sensitization of the skin.  According to EPA, the document, Draft Interim Science Policy:  Use of Alternative Approaches for Skin Sensitization as a Replacement for Laboratory Animal Testing, “describes the science behind the non-animal alternatives that can now be used (in vitro, in silico, in chemico) to identify skin sensitization.”  The draft Science Policy states that the Office of Pesticide Programs (OPP) and Office of Pollution Prevention and Toxics (OPPT) will immediately begin to accept submissions of new approach methodologies (NAM) and defined approaches (DA) as described in the draft Science Policy.  EPA notes that there are multiple domestic and international activities ongoing that will allow for refinement and expansion of this draft Science Policy to other DAs and additional NAMs and support global harmonization of DAs for skin sensitization.  According to the draft Science Policy, OPP and OPPT “will continue to be active participants in these activities to ensure regulatory acceptance and will continue to support cross-sector collaborations that enhance animal welfare, and accelerate the implementation of NAMs.”  Comments on the draft Science Policy document must be submitted to Docket Number EPA-HQ-OPP-2016-0093 by June 9, 2018.

The draft Science Policy is the result of national and international collaboration between the Interagency Coordinating Committee on the Validation of Alternative Methods, the National Toxicology Program’s Interagency Center for the Evaluation of Alternative Toxicological Methods, the European Union Reference Laboratory for Alternatives to Animal Testing, and Health Canada’s Pest Management Regulatory Agency.


 

By Lisa M. Campbell and James V. Aidala

On May 9, 2016, Jack Housenger, Director of the U.S. Environmental Protection Agency’s Office of Pesticide Programs (OPP), announced the selection of Anna Lowit for the Senior Science Advisor Position in OPP’s Immediate Office. 

Lowit has been a toxicologist in OPP’s Health Effects Division since 1998. Housenger’s announcement of Lowit’s selection notes that she has “provided expert technical advice and guidance to senior management on issues related to toxicity testing, human risk assessment, and science policy issues,” and that she “provided substantial input to enhance science quality and ensured that scientifically accepted procedures and consistent criteria were applied, so that OPP’s risk assessments were recognized as reflecting the state-of-the-science.”

In light of the many current and expected issues involving fundamental science policy issues -- such as the application of the Food Quality Protection Act (FQPA) 10X safety factor, endocrine effects tests and their meaning, utilization of information from epidemiological studies, regulatory application of constantly evolving cancer assessment methodologies, and the appropriate approach to evaluating products of synthetic biology -- the Senior Science Advisor position is among the most important positions on the organization chart of OPP.


 

By Lisa M. Campbell, James V. Aidala, and Susan Hunter Youngren, Ph.D.

The U.S. Environmental Protection Agency’s (EPA) January 5, 2015, release for public comment of the revised human health risk assessment of chlorpyrifos (http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPP-2008-0850-0195) reflects another step taken to implement its new spray drift and volatilization policies. These policies were long in the making and the subject of significant discussion and controversy over the years. EPA, with this assessment, has also taken a very public step to implement its controversial policy, announced in December 2009, to apply, effectively, Food Quality Protection Act (FQPA) risk assessment techniques to pesticide uses not subject to FQPA, as part of its commitment to environmental justice.

The spray drift and volatilization policies were discussed in an October 2014 webinar and discussed in our September 17, 2014, memorandum. EPA’s Revised Risk Assessment Methods for Workers, Children of Workers in Agricultural Fields, and Pesticides with No Food Uses, issued in 2009, is discussed in our December 8, 2009, memorandum.

Spray Drift and Volatilization

EPA had been assessing spray drift and volatilization for chlorpyrifos for a number of years, and many of the EPA-derived spray drift and volatilization tools are based on chlorpyrifos data. The January 5 assessment updates the assessment conducted in 2011. This document assesses both potential risks to workers (mixing/loading/applying and re-entry) as well as potential risks to residents (bystanders and food/water consumption). The bystander assessment uses the new tools that EPA released in Spring 2014 to assess potential risks from volatilization and spray drift (as discussed in the B&C webinar). The buffer zones EPA had previously estimated to mitigate spray drift are reduced in the new assessment. The risks noted in the assessment were for workers and specific water areas.

FQPA Risk Assessment Methods Use for Non-FQPA Assessment

In addition to implementing its spray drift and volatilization policies, EPA also assessed exposure in a manner that appears intended to implement the 2009 policy that was the subject of much concern when released for public comment. In that policy, EPA stated its intent to apply risk assessment techniques developed in implementing FQPA’s “extra safety factor” to any pesticide product’s risk assessment, regardless of whether it falls under FQPA, “so long as application of the risk assessment technique is consistent with good scientific practice and is not otherwise prohibited by law.” EPA stated then that this would include “using an additional safety/uncertainty factor to protect children,” as well a number of other factors. EPA announced this policy originally as part of its commitment to considerations of environmental justice.

The chlorpyrifos assessment is based on a physiologically-based, pharmacokinetic-pharmacodynamic (PBPK-PD) model to estimate the toxicologic Points of Departure (POD), thus deriving different toxicological values of concern based on the age, sex, and duration of exposure. The PBPK-PD model is also used to estimate intra-species uncertainty factors (UF), as there is no need for inter-species factors because the model estimates human red blood cell (RBC) acetylcholinesterase/cholinesterase (AChE/ChE) inhibition. Based on the PBPK-PD model, a 10X intra-species factor was used for females of childbearing years whereas it was 4X for all other groups assessed.

The worker of concern in the assessment is defined to be a female of childbearing years due to concern of not only RBC AChE/ChE inhibition, but also the potential for neurodevelopmental effects as seen in epidemiological studies. The epidemiological studies are controversial because there have been many questions about actual exposure to chlorpyrifos, particularly as two studies measured a biomarker that can be seen from exposure to other organophosphates (OP). The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Science Advisory Panel (SAP) reviewed EPA’s assessments of these studies in 2008 and 2012. The SAP concluded that “chlorpyrifos likely played a role” in the observed neurodevelopmental outcomes. EPA determined that based on the weight of evidence (WOE) from animal studies and epidemiological studies, reduction of the 10x “FQPA Safety Factor (SF)” was not appropriate. The residential dietary assessments were compared to a Margin of Exposure (MOE) of 100 (10X FQPA SF x 10X intra-species factor) for women and an MOE of 40 (10X FQPA SF x 4X intra-species factor) for all other ages. The occupational assessments were compared to an MOE of 100 for women and 40 for all other age groups (with no explanation of the reasoning behind those values).

This is noteworthy and should be examined closely because EPA has effectively used an additional “FQPA factor” as a safety factor for occupational assessments. EPA stated in its press release announcing the assessment that potential restrictions may be necessary to protect workers and water.

Next Steps

There is a 60-day comment period for this document, which are due on or before March 16, 2015. Among the issues commenters are likely to address include:

     Use of the PBPK-PD model to estimate PODs;

     Use of the PBPK-PD model to estimate intra-species uncertainty factors;

     Use of the epidemiological data; and

     Use of a 10X SF for occupational exposure.

The full impact of this assessment is not yet clear, but it raises many issues of interest to registrants.