By Lara A. Hall, MS, RQAP-GLP and Heather F. Collins, M.S.

On March 17, 2021, the U.S. Environmental Protection Agency (EPA) announced the issuance of the final guidance document entitled "Guidance for Waiving Acute Dermal Toxicity Tests for Pesticide Technical Chemicals & Supporting Retrospective Analysis" (EPA 705-G-2020-3722; Docket ID: EPA-HQ-OPP-2016-0093) that expands the potential for data waivers for acute dermal studies to single technical active ingredients (AI) used to formulate end-use products. This new guidance builds upon the final guidance for waiving acute dermal toxicity tests for pesticide formulations published by EPA on November 9, 2016, and is an example of EPA’s continued efforts to reduce animal testing and achieve its goal of eliminating all EPA requests for studies and EPA funding of studies on mammals by 2035.  EPA states that this guidance is expected to reduce the number of test animals used annually by approximately 750, as well as save EPA, industry, and laboratory resources.

The new final guidance document also allows EPA to harmonize with the Pest Management Regulatory Agency (PMRA) of Canada, which published guidance on acute dermal toxicity waivers for both end-use product formulations and technical chemicals in 2017. 

In developing the new guidance, EPA states that the Office of Pesticide Programs (OPP) and the National Toxicology Program (NTP) Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM) conducted a retrospective analysis of rat acute oral and acute dermal LD50 studies for 249 AIs across numerous chemical classes and toxicity categories in the EPA pesticide categorization scheme.  The overall purpose of this analysis was to address the utility of the acute dermal toxicity study for single AIs in pesticide labeling, such as the signal word and precautionary statements. Fumigants and rodenticides were excluded from this retrospective analysis based on their physical state and/or anticipated exposures to them. EPA concluded that:

• For 67 percent of the 249 technical chemicals, the results of both oral and dermal acute toxicity studies fall within the same Toxicity Category; 
• For 32 percent of the chemicals, the oral study falls within a lower (i.e., more protective) Toxicity Category;
• Thus, for 99 percent of the chemicals in the analysis, if the dermal study had not been available and labeling had been based only on the Toxicity Category for the oral acute toxicity study, the labeling requirements would have been equally or more protective; 
• For the two remaining chemicals (less than 1 percent), factors other than the dermal acute toxicity may influence labeling requirements; and
• The acute dermal toxicity studies provide little to no added value in regulatory decision making. 

EPA states that it believes the retrospective analysis fully supports the conclusion that waivers may be granted for acute dermal toxicity studies for pesticide technical chemicals, except for fumigants and rodenticides.  Waivers may be accepted for fumigants and rodenticides on a case-by-case basis with appropriate scientific rationale. EPA maintains the ability to request acute dermal toxicity data on a case-by-case basis, but states that it anticipates granting the waiver in most cases.

Additional information on EPA’s efforts to reduce animal testing is available here.

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By Lisa M. Campbell, Lara A. Hall, MS, RQAP-GLP, and Heather F. Collins, M.S.

On October 7, 2020, the U.S. Environmental Protection Agency (EPA) announced that it is requesting comments on its draft guidance that would allow registrants, in certain circumstances, to forgo testing chemicals on animal skin to determine whether a pesticide would lead to adverse effects.  This new draft guidance is part of EPA’s continued efforts to reduce animal testing and achieve its goal of eliminating all EPA requests for studies and EPA funding of studies on mammals by 2035.

According to EPA, the draft dermal toxicity guidance would allow applicants to request waivers for acute dermal toxicity studies on single-active ingredients used to develop end-use products.  The new draft guidance also allows EPA to harmonize with the Pest Management Regulatory Agency (PMRA) of Canada, which published guidance on acute dermal toxicity waivers for both formulations and technical chemicals in 2017.  The draft guidance is in addition to the final guidance for waiving acute dermal toxicity tests published by EPA in November 2016 for pesticide formulations.

In developing the guidance, EPA states that it conducted a retrospective analysis of rat acute oral and acute dermal LD50 studies for 249 active ingredients across numerous chemical classes and toxicity categories.  Fumigants and rodenticides were excluded from this analysis, based on their physical state and/or anticipated exposures to them.  EPA concluded that for 67 percent of the 249 technical chemicals, the results of both oral and dermal acute toxicity studies fall within the same Toxicity Category.  For 32 percent of the chemicals, the oral study falls within a lower (i.e., more protective) Toxicity Category; thus, for 99 percent of the chemicals in the analysis, if the dermal study had not been available and labeling had been based only on the Toxicity Category for the oral acute toxicity study, the labeling requirements would have been equally or more protective.  For the two remaining chemicals (less than 1 percent), factors other than the dermal acute toxicity may influence labeling requirements.  EPA concluded that its requirements for such acute dermal toxicity studies provide little to no added value in regulatory decision making.  EPA states that this guidance, when finalized, is expected to reduce the number of test animals used annually by approximately 750, as well as save EPA, industry, and laboratory resources.

EPA states that it believes the retrospective analysis fully supports the conclusion that waivers may be granted for acute dermal toxicity studies for pesticide technical chemicals, except for fumigants and rodenticides.  Waivers may be accepted for fumigants and rodenticides on a case-by-case basis with appropriate scientific rationale.  Once the guidance is issued in final form, EPA states that applicants who wish to pursue waivers for these studies would submit formal waiver requests as part of the registration application through existing processes and cite the guidance as support for the requests.  EPA maintains the ability to request acute dermal toxicity data on a case-by-case basis, but states that it anticipates granting the waiver in most cases.

Comments on the draft guidance are due on or before November 9, 2020, and can be submitted at http://www.regulations.gov under Docket ID No. EPA-HQ-OPP-2016-0093.

EPA also announced the launch of its new webpage that provides metrics and strategies for reducing and replacing animal testing, including links and resources to all pertinent guidance and work plans tied to the larger Toxicology in the 21st Century Initiative across the federal government.  The directive, issued by EPA Administrator Andrew Wheeler in September 2019, calls for EPA to reduce animal testing and to reduce funding 30 percent by 2025 and eliminate it by 2035.  EPA states that its actions to date to support these efforts include:

• In September 2019, EPA announced $4.25 million in funding for five universities to research and develop alternative test methods for evaluating chemical safety.
• In December 2019, EPA convened a conference for achieving reduced animal testing in chemical safety research and updated its list of New Approach Methodologies (NAM) that could be used in EPA’s work under the amended Toxic Substances Control Act, including adding 21 new test guidelines related to health and ecological effects and six additional EPA policies that reduce the use of animal testing.
• In June 2020, EPA released a NAMs work plan that details how EPA plans to develop, test, and apply chemical safety testing approaches without the use of animals.
• In February 2020, EPA issued final guidance waiving the subacute dietary testing of pesticides on birds when the additional information is unnecessary to support a pesticide registration decision, which is expected to save 720 test animals annually.
• In July 2020, EPA announced new guidance to reduce unnecessary testing on fish, which is expected to save 240 test animals annually.

EPA will host its Second Annual Conference on the State of the Science on Development and Use of NAMs for Chemical Safety Testing virtually on October 19 and 20, 2020.  Additional information on EPA’s efforts to reduce animal testing is available here.

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By Lisa M. Campbell and James V. Aidala

On April 8, 2019, the Agency for Toxic Substances and Disease Registry (ATSDR) announced 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.

The draft profile includes a chapter on glyphosate’s potential for human exposure, which states the following in the overview:

• “Glyphosate has not been identified in any of the 1,832 hazardous waste sites that have been proposed for inclusion on the [U.S. Environmental Protection Agency (EPA)] National Priorities List (NPL) (ATSDR 2015). However, the number of sites evaluated for glyphosate is not known.” 
• “Occupational and residential exposure is a result of glyphosate’s use in agricultural, nonagricultural, industrial, and residential settings. The highest potential for dermal, inhalation, and ocular exposure is expected for pesticide applicators, farm workers, and home gardeners who use herbicides containing glyphosate.”
• “The general population is exposed to glyphosate via ingestion of crops, plants, and foods with residues of this chemical. Residential exposure may occur via inhalation, dermal contact, and/or ocular contact during mixing or application of consumer products containing glyphosate or by coming into contact with crops, soils, or water to which glyphosate-containing products have been applied.”
• “Occupational exposure to glyphosate may occur via inhalation, dermal contact, and/or ocular contact during manufacture, transport, mixing, loading, application, and disposal processes. Accidental oral exposure may occur via unintentional ingestion. Dermal contact appears to be the major route of exposure to glyphosate for individuals involved in its application.”
• “Glyphosate mainly enters the environment as a direct result of its herbicidal use. Fate of this chemical in the environment includes degradation, transport, and partitioning processes, which are governed by its physicochemical properties and by abiotic or biotic degradation under certain environmental conditions. Glyphosate is a nonvolatile, highly polar, non-residual herbicide that has low potential for environmental persistence and is unlikely to bioaccumulate.”

 Commentary

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.  Meanwhile, EPA continues its work on the registration review of the herbicide.  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.  After the public comment period for the draft human health and ecological risk assessments ended in April 2018, EPA officials have stated they hope to complete the registration review sometime this year.

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By James V. Aidala and Margaret R. Graham, M.S.

On March 21, 2019, the U.S. Environmental Protection Agency (EPA) announced it was updating its Residual Time to 25% Bee Mortality (RT₂₅) Data Table with information it has collected since the table was first published in 2014.  EPA states that the “RT₂₅ data help farmers and beekeepers know about how long a specific pesticide may remain toxic to bees and other insect pollinators following foliar application to crops,” and the new data “reflect the results of studies the agency has analyzed as part of [its] routine pesticide regulatory activities.”  One example that EPA provides regarding how this new data will work is that farmers can now “choose pesticides that quickly lose their toxicity to bees,” and that applying the products in the evening “helps ensure that by morning the pests have been dealt with and blooming crops are safe for bees.” 

EPA states that RT₂₅ values are a function of a number of factors including application rate, physical-chemical properties, dissipation, crop, and pesticide formulation.  The values provided were compiled from registrant-submitted data submitted to fulfill the data requirement for Honey Bee (Apis mellifera) Toxicity of Residues on Foliage study (OCSPP Guideline 850.3030).  EPA states that the honey bee toxicity of residues on foliage study “is a laboratory test designed to determine the length of time over which field weathered foliar residues remain toxic to honey bees, or other species of terrestrial insects” and, depending on the chemical tested, “either the technical grade active ingredient or a specific formulation was tested using either the honey bee, alfalfa leaf cutting bee, or alkali bee.”  The data table lists the test material, the species tested, and the plant species on which residues were aged.

EPA plans to update the table annually as it collects additional data going forward.  More information on EPA’s actions intended to protect pollinators is available on EPA’s website.

Commentary

In addition to providing the residual toxicity values, the table also illustrates the wide range of toxicity values among the various pesticides.  RT₂₅ times for the different active ingredients can range between a few and over 500 hours to reach the RT₂₅ threshold.  Even different formulations using the same active ingredient can have a significant difference in toxicity values.  This illustrates the importance of reading the specific label instructions for a pesticide, even one that might be generally familiar to the user.

EPA’s publication of this information online also imposes a duty for EPA to continually update the table, especially to capture any changes in the information appearing in an earlier listing of the data.  If, upon further review or later data submissions there are changes to the table for a product, EPA will need to alert users to potentially important changes in the information.  Again, this illustrates the need for reading the label for each pesticide at the time of application, since some important information may have changed.

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By Lisa M. Campbell and Lara A. Hall, MS, RQAP-GLP

On August 21, 2018, the U.S. Environmental Protection Agency (EPA) announced it was posting new frequently asked questions (FAQ) for registrants and contract laboratories conducting honeybee toxicity testing.  EPA states that these FAQs are “made up of responses to inquiries EPA commonly receives about protocols used to generate honeybee toxicity data for submission in support of pesticide registration,” and are “meant to complement the Agency’s existing Pollinator Risk Assessment Guidance and increase the transparency and clarity of the risk assessment process.”  The FAQs include general study questions and questions related to specific kinds of contact toxicity, oral toxicity, chronic toxicity, toxicity of residues on foliage, and field and tunnel colony toxicity levels.  Questions not found in the FAQs or risk assessment guidance can be submitted to .(JavaScript must be enabled to view this email address).

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By Lisa M. Campbell and Lisa R. Burchi

On March 8, 2018, the U.S. Environmental Protection Agency (EPA) announced its release of final guidance clarifying where first aid statements should appear on the label of pesticide products.  EPA also posted a response to public comments.  Links to the final guidance and to the response to public comments documents are below:

• First Aid Guidance Document -- EPA’s Guidance for Pesticide Registrants on Location of the First Aid Statement per 40 CFR 156.68.
• First Aid Guidance: Response to Public Comments on EPA’s Guidance for Pesticide Registrants on Location of the First Aid Statement and Clarification on Definition of Label “Panel” per 40 CFR 156.68.

EPA states that it was prompted to develop this guidance when it learned “that there was a discrepancy in how the ‘location of first aid statement,’ per [40 C.F.R. Section 156.68(d)] is interpreted by EPA and those in the pesticide registrant community.”  EPA notes that its review and approval of pesticide labeling is generally of a “master” label and thus does not always include a review of the location or placement of specific language on a label.

On December 7, 2016, EPA posted a memorandum for public comment entitled “EPA’s Guidance for Pesticide Registrants on Location of the First Aid Statement and Clarification on Definition of Label ‘Panel’ per 40 CFR 156.68” to clarify the interpretation of the term “panel” in the context of 40 C.F.R. 156.68 and to clarify where first aid statements must appear on pesticide labels, based on their Toxicity Category.

In its final guidance, EPA states it “will continue to require that Toxicity Category I products have the first aid statements on the front panel except in cases where a variation has been approved.”  Further, based on comments received and the wide reliance by the regulated community on the interpretation that “any panel” includes inside panels, EPA is changing its position from its 2016 memorandum and now “will not require Toxicity Category II and III products to bear the first aid statements on a visible front, back or side panel.” 

EPA also listed three recommendations for registrants to consider when printing their container labels:

1. For Toxicity Category I products, EPA strongly recommends that registrants consider placing duplicative first aid language on the very back page of the booklet/accordion/saddle stitch label that is immediately “stuck” to the container in case the booklet/accordion/saddle stitch label is accidentally removed.
2. Regardless of whether a registrant chooses to place the first aid statements for Toxicity Categories II and III products on a visible front, back, side or inside panel, EPA recommends that duplicative first aid language appear on the very back page of the booklet/accordion/saddle stitch label that is immediately attached to the container in case the booklet/accordion/saddle stitch label is accidentally removed. EPA states that this recommendation is not intended to suggest other information that registrants typically include on the very back page should be moved elsewhere.
3. EPA recommends that the registrant community consider designing new booklets/accordion/saddle stitch labels that are not easily removed from the containers.  Per 40 C.F.R. Part 156.10(a)(4), the labels are to be “securely attached” to the immediate container of the pesticide product.  EPA believes that in many instances these labels are easily removed which is why, EPA states, it believes many registrants have already chosen to put the duplicative first aid statements on the very last page of the label that is attached to the container.

Registrants should review this guidance carefully, as this issue has been the subject of concern and controversy for a number of registrants.

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By Lynn L. Bergeson, Karin F. Baron, and Margaret R. Graham

On December 20, 2016, the U.S. Environmental Protection Agency (EPA) announced the start of a pilot program to evaluate the usefulness and acceptability of a mathematical tool (the GHS Mixtures Equation), which is used in the Globally Harmonized System of Classification and Labeling of Chemicals (GHS).  EPA states that the goal of the pilot program is to “evaluate the utility and acceptability of the GHS Mixtures Equation as an alternative to animal oral and inhalation toxicity studies for pesticide formulations.”

For this pilot program, EPA is requesting submission of acute oral and acute inhalation toxicity study data paired with mathematical calculations (GHS Mixtures Equation data) to support the evaluation of pesticide product formulations; instruction for doing so are available on the GHS Equation Pilot Program webpage, and Guidance on the GHS Mixtures Equation is available in the Guidance on the Application of the CLP (Classification, Labeling and Packaging) Criteria.

The program is an interesting approach considering the conceptual differences of risk assessment and hazard determination that exist at the core of  EPA risk approaches and GHS fundamentals.  Also, the definition of the EPA Categories compared to GHS has been problematic for hazard communication applications. 

Mixture calculation tools rely on the availability of data for all components and would only be applicable if the data for each were generated using the same species under similar exposure conditions.  

This pilot program is being developed under EPA’s initiative to develop non-animal alternatives for acute toxicity testing, as well as EPA’s Office of Pesticide Programs’ Strategic Vision for Adopting 21st Century Science Methodologies.  More information on these initiatives can be found on our Pesticide Law and Policy blog under key phrase “toxicity testing.”

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By Lisa M. Campbell and Timothy D. Backstrom
 
On July 5, 2016, a three judge panel of the U.S. Court of Appeals for the Ninth Circuit issued a brief opinion denying a petition for review of a U.S. Environmental Protection Agency (EPA) order in which EPA declined to “immediately adopt interim prohibitions on the use of toxic drift-prone pesticides … near homes, schools, parks, and daycare centers or wherever children congregate.”  Petitioners Pesticide Action Network North America (PANNA), United Farm Workers, and Pineros y Campesinos Unidos del Noroeste (PANNA, et al.) filed an administrative petition in 2009 asking EPA to conduct pesticide-specific drift assessments and to impose interim buffer zones to protect children from pesticide drift.
 
The Circuit Court agreed with EPA’s contention that the petitioners do not have jurisdiction to review the reregistration and tolerance determinations previously made by EPA pursuant to the Food Quality Protection Act (FQPA), because such challenges are now time barred.  EPA agreed with the petitioners that it should consider potential risks from spray drift as part of the registration review under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).  The petitioners argued that EPA had thereby acknowledged legal error when it previously reregistered food-use pesticides, but EPA has vigorously contested that premise.  In 2014, EPA issued a proposal describing the methodology for assessing risk from pesticide drift that EPA will use prospectively in making registration review decisions.
 
The petitioners requested that EPA adopt interim relief by imposing uniform buffer zones for all pesticides that are registered for application by ground sprayers, broadcast, or aerial application, and that may cause certain human health effects.  EPA rejected this request for across-the-board buffer zones as unscientific and inefficient and likely to result in a misallocation of EPA resources.  The Circuit Court concluded that “substantial evidence” supports EPA’s decision to deny this interim relief, stating that “[t]he record suggests that the risk of exposure to pesticide draft depends on a number of factors, including pesticide toxicity, the method of application, the size of pesticide droplets, and weather conditions,” and “adequately supports EPA’s conclusion that the imposition of uniform buffer zones is not the most ‘scientifically appropriate’ method for mitigating the risk of exposure to pesticide drift.”

Commentary

The Circuit Court has clearly recognized that uniform buffer zones like those sought by the petitioners would not be “scientifically appropriate.”  While this decision is both welcome by industry and constructive, the evaluation of potential exposure and risk from pesticide drift during the registration review process for individual pesticides will likely remain controversial.

More information on EPA’s spray drift policy is available in our memorandum Spray Drift and Volatilization: Issues to Navigate Carefully as EPA Develops Registration Review Decisions.

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By Lisa M. Campbell and Margaret R. Graham

On March 17, 2016, the U.S. Environmental Protection Agency’s (EPA) Office of Pesticide Programs (OPP), announced in an open letter to stakeholders, that it has developed new tools to “enhance the quality of its risk assessments and risk management decisions and better ensure protection of human health and the environment from pesticide use.”  These tools have been developed as part of EPA’s efforts to implement OPP’s Strategic Vision for Adopting 21st Century Science Methodologies (Strategic Vision) initiative.  As part of this initiative, OPP released two guidance documents:

1. Final Guidance:  Process for Establishing & Implementing Alternative Approaches to Traditional In Vivo Acute Toxicity Studies.  OPP states that this guidance will “expand the use of alternative methods for acute toxicity testing” and “describes a transparent, stepwise process for evaluating and implementing alternative testing methods (not using live animals) for acute oral, dermal and inhalation toxicity, along with skin and eye irritation and skin sensitization.”  
2. Draft Guidance:  Retrospective Analysis & Guidance for Waiving Acute Dermal Toxicity Tests for Pesticide Formulations. OPP states that this draft guidance “to waive all acute lethality dermal studies for formulated pesticide products” was developed through an analysis “across numerous classes representing conventional pesticides, antimicrobials, and biopesticides [that] examined the utility of the acute dermal toxicity study for formulations in pesticide labelling for end-use products.”  

Comments on the draft guidance for waiving acute dermal toxicity tests are due May 16, 2016.  The National Research Council’s 2007 report, Toxicity Testing in the 21st Century:  A Vision and a Strategy, instigated OPP’s Strategic Vision initiative.  EPA states that these guidance documents are significant steps in the report’s implementation and intended to reduced animal testing. 

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

The Environment Protection Agency (EPA) extended the comment date on its draft guidance, Pesticide Cumulative Risk Assessment: Framework for Screening Analysis, in a Federal Register notice published on August 28, 2015.  EPA’s draft framework provides guidance on how the EPA will screen groups of pesticides for cumulative evaluation.  EPA proposes using a two-step approach, beginning with the evaluation of available toxicological information and, if necessary, followed by a risk-based screening approach.  This framework supplements the existing guidance documents for establishing common mechanism groups (CMG) and conducting cumulative risk assessments (CRA).  Additionally, EPA is also seeking comments on a draft copy of the human health risk assessment where the cumulative assessment was conducted in conjunction with pending actions for abamectin.

EPA has described a process that is data intensive and that requires sophisticated knowledge and modeling.  EPA acknowledges that “the level of refinement provided by this approach is not necessary or even feasible for all existing pesticide classes.”  The policy documents for conducting the first step in the process, “developing CMGs,” are still being refined.

This document provides the guidance for screening information to identify candidate CMGs and does not outline how actually to conduct CRAs.  Rather, this document relies on policies and principles provided in other documents found on the EPA cumulative risk assessment website.  These additional policies and principles were developed during the conduct of five CRAs for chemical groups such as the organophosphates and carbamates.

One of the major questions raised by the issuance of this document is the extent of the information that EPA will require for each chemical to determine if there are CMGs.  The five CMGs currently assessed have relatively well defined mechanisms of action.  It is not clear, however, what EPA will consider to be adequate justification that there are no other chemicals with the same mechanism of action for other chemicals of concern.

Requirements for EPA to determine and assess the risks of possible common mechanism of action among groups of similar pesticides was one of the most far-reaching new requirements imposed by the Food Quality Protection Act.  Some observers expected a larger impact on pesticide use than what has occurred to date; whether EPA’s new approach results in more groupings or otherwise leads to restrictions on more groups of pesticides remains to be seen.

Comments on the draft guidance are due September 28, 2015.  More information regarding EPA’s assessment of pesticide cumulative risk is available online.

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