By Lisa M. Campbell, Sheryl L. Dolan, and Barbara A. Christianson
On September 6, 2017, the U.S. Environmental Protection Agency (EPA) published a notice in the Federal Register announcing the availability of and seeking public comment on draft guidance, Pesticide Registration Notice (PR Notice) 2017-XX: Notifications, Non-notifications and Minor Formulation Amendments. EPA states it is issuing this notice to “align the notification program with the requirements of the Food Quality Protection Act (FQPA) and [the Pesticide Registration Improvement Act (PRIA)] and to clarify the processes for accepting minor, low risk registration amendments to be accomplished through notification, non-notification or as accelerated amendments.” EPA is requesting comments, and specifically information on projected cost implications of this draft updated guidance.
PR Notices are issued by the Office of Pesticide Programs (OPP). EPA states that PR Notice 2017-XX will update and clarify “the scope of changes accepted by notification, non-notification and minor formulation amendments for all pesticide products, and supersedes both PR Notices 95-2 and 98-10 in their entirety.” The PR Notice lists the changes from PRN 98-10 in a table. Those changes include:
In addition to the changes listed on the table, modifications to PR Notice 98-10 consist of the following:
- F. Product Composition: (1) Pesticide Category -- Under PR Notice 98-10, the pesticide categories "disinfectant" and "sanitizer" were two pesticide categories that were allowed to be added to a label by notification. Under the proposed PR Notice, "disinfectant" and "sanitizer" were removed.
- F. Product Composition: (2) Odor -- Under PR Notice 98-10, the terms "fragrance free" and "unscented" were allowed to be added to a label by a notification provided that the product is odorless or nearly odorless and contains odor-masking ingredient such as a perfume. Under the proposed PR Notice, these terms were removed.
Minor Formulation Amendments
- A. Minor Formulation Amendments: (1) Addition, deletion or substitution of one or more colorants in a formulation -- Under PR Notice 98-10, if a product was intended for a use as a seed treatment or rodenticide, it would not be eligible for an accelerated review; that restriction was deleted from the proposed PR Notice.
- A. Minor Formulation Amendments: (2) Addition, deletion or substitution of one or more inert ingredients (other than colorants and fragrances) in a formulation -- Under the proposed PR Notice, if a product is a dog/cat pet spot-on product or if an inert is a bittering agent or a safener, the product would not be eligible for an accelerated review.
- A. Minor Formulation Amendments: (3) Addition, deletion or substitution of one or more fragrances in a formulation -- Under the proposed PR Notice, fragrances will be eligible for an accelerated review if all fragrance component ingredients are included on the Fragrance Ingredient List; individual fragrance component ingredients that exceed 0.1 percent (by weight) of the total pesticide product composition have existing approval for non-food use as an inert ingredient; and new/modified fragrances for antimicrobial products making public health claims are within the certified limits established for fragrances already approved for the product.
- Under the proposed PR Notice, products that are not eligible for accelerated review under minor formulation amendments are:
- Pet spot-on products;
- Change to an active ingredient source;
- Change to nominal concentration of the active ingredient; or
- Addition of new or additional Confidential Statements of Formula (CSF).
EPA Procedures to Review Notifications
Under the proposed PR Notice, EPA outlines changes to the policy for processing notifications by the Registration Division (RD) and the Biopesticides and Pollution Prevention Division (BPPD), but procedures to process notifications by the Antimicrobials Division remain the same.
One item to note under the proposed notification process for RD and BPPD is that a registrant may distribute or sell a product modified by notification once EPA receives the notification but, if EPA determines that a product has been modified through notification inappropriately, EPA may initiate regulatory and/or enforcement action without first providing the registrant with an opportunity to submit an application to amend the registration.
Registrants Submitting Minor Formulation Amendments
Under the proposed PR Notice, EPA requires that registrants submit with their application for registration a cover letter listing names and dates of all EPA accepted CSFs. EPA will consider any CSFs not listed in the cover letter as superseded/no longer valid.
Comments on this PR notice are due October 6, 2017, and can be submitted online under Docket ID EPA-HQ-OPP-2016-0671.
Registrants should review the draft PR Notice carefully, as it includes important changes. For example, the consequence for submitting a minor formulation amendment and neglecting to include a list of all current CSFs is severe. As another example, EPA signals in its proposal that proceeding to market with a product revised through the notification process may be risky if the submitter has erred in its judgment regarding what is eligible for a notification. Should the PR Notice be issued without change to this provision, submitters may wish to give close consideration to waiting until it has EPA’s written confirmation that a notification has been accepted before introducing the revised product to market. Comments on issues of concern should be considered.
By Lisa M. Campbell, Timothy D. Backstrom, and James V. Aidala
A noteworthy development in the U.S. Environmental Protection Agency’s (EPA) ongoing and controversial consideration of the potential use of epidemiological data in its pesticide risk assessments occurred on May 25, 2017, when EPA placed in the public dockets for certain organophosphate (OP) pesticides an “update” of the September 15, 2015, Literature Review and Food Quality Protection Act (FQPA) determination, along with a response to comments on the original document. These documents were signed by EPA scientists on December 29, 2016, prior to the new Administration, but were placed in the docket only last month, under the new Administration. The documents attempt to rebut the various criticisms of EPA’s assessment of the epidemiology studies for chlorpyrifos and the original FQPA safety factor determination for OP pesticides, and they reaffirm the policy embodied in the original Literature Review. Because these new documents were signed in the last days of the Obama Administration, they may be viewed by some industry stakeholders as an effort by some at EPA to “lock in” the prior policy concerning OP pesticides.
The public release of the “updated” Literature Review and response to comments must be considered in the context of the ongoing chlorpyrifos battles that have received significant public attention. During the five months between the date that these “update” documents were signed and the date that EPA placed them in the public docket, EPA Administrator Pruitt issued a decision on March 29, 2017, to deny the petition filed by the Pesticide Action Network North America (PANNA) and the National Resources Defense Council (NRDC) requesting that EPA revoke all tolerances and cancel all registrations for chlorpyrifos products. See EPA Denies Petition to Ban Chlorpyrifos. In his denial decision, Administrator Pruitt concluded it would be appropriate for EPA to defer determining whether chlorpyrifos is likely to cause neurodevelopmental effects at exposure levels below the levels that cause acetylcholinesterase (AChE) inhibition until the completion of the registration review process for chlorpyrifos. Administrator Pruitt based his decision on the premise that “the science addressing neurodevelopmental effects remains unresolved” and that “significant uncertainty … exists regarding the potential for chlorpyrifos to cause adverse neurodevelopmental effects.”
Some industry stakeholders may argue that the decision by the EPA scientists who prepared the “updated” Literature Review which concluded that EPA should retain the 10X FQPA uncertainty factor for OP pesticides can be reconciled with Administrator Pruitt’s subsequent denial decision, because the “updated” FQPA safety factor determination does not preclude further scientific discussion concerning the potential for neurodevelopmental effects from OP pesticide exposures. On the other hand, other industry stakeholders may be concerned about the immediate adverse impact of this “updated” FQPA determination on the risk assessments prepared by EPA for OP pesticides and the measures that will be demanded by EPA to mitigate purported risks.
On April 5, 2017, PANNA and NRDC responded to Administrator Pruitt’s March 29, 2017, decision to deny their petition to revoke the tolerances and cancel the registrations for chlorpyrifos by submitting to the Ninth Circuit Court of Appeals a Motion for Further Mandamus Relief. That motion was substantially based on the premise that EPA does not “suggest that it has reconsidered its finding that chlorpyrifos is unsafe.” The briefing on the new mandamus motion was completed on May 5, 2017, several weeks before EPA disclosed the documents concerning the “updated” FQPA determination. Nevertheless, petitioners could try to argue that these documents constitute further evidence supporting their key premise that EPA has not actually revisited its prior determination that chlorpyrifos exposures are unsafe.
The legal and policy issues posed by EPA’s evaluation of the epidemiological data for chlorpyrifos and by EPA’s determination that these data create sufficient uncertainty to warrant retention of the FQPA 10X safety factor for all OP pesticides will be a continued source of controversy, and will be watched with interest by all stakeholders.
More information and updates on chlorpyrifos, the epidemiological data, and their surrounding legal issues is available on our blog item under keyword chlorpyrifos.
By Lisa M. Campbell, Timothy D. Backstrom, and Lisa R. Burchi
On August 12, 2016, a three-judge panel of the Ninth Circuit Court of Appeals issued an order denying the U.S. Environmental Protection Agency’s (EPA) request for an additional six months to decide whether to ban agricultural uses of chlorpyrifos. The court opted instead to afford EPA a three month extension, stating that “this is the final extension, and the court will not grant any further extensions."
EPA sought the six month extension on June 29, 2016, to allow time for EPA to complete two scientific analyses that may bear on EPA’s conclusions in the final rule, and to request further public comment before taking final action on a prior proposal to revoke all chlorpyrifos tolerances. The two analyses that EPA wanted to complete are: (1) a refined drinking water assessment that may allow EPA “to develop more tailored risk mitigation for some regions of the country,” and (2) an evaluation of the epidemiological data for chlorpyrifos to determine whether EPA should retain the point of departure based on acetylcholinesterase (AChE) inhibition in the proposed rule.
The court concluded that EPA’s request for a six month extension “is not justified in light of EPA’s history in this matter as well as the court’s previous extensions.” The court stated that EPA’s request was "another variation on a theme 'of partial reports, missed deadlines, and vague promises of future action' that has been repeated for the past nine years,” and that “nothing has changed that would justify EPA’s continued failure to respond to the pressing health concerns presented by chlorpyrifos."
The court ordered EPA to take final action on its proposal to revoke tolerances for chlorpyrifos by March 31, 2017. A further status report by EPA will be due in November 2016.
EPA’s updated analysis of the epidemiological data for chlorpyrifos will be a matter of considerable interest. After EPA issued a proposed rule utilizing a point of departure for chlorpyrifos based on AChE inhibition, EPA issued a blanket determination based on the epidemiological data for chlorpyrifos in which EPA decided to retain the Food Quality Protection Act (FQPA) safety factor for all organophosphate (OP) pesticides. This FQPA determination could cause EPA to conclude that the tolerances for chlorpyrifos must be revoked regardless of the outcome of the refined drinking water assessment.
EPA later proposed to use an alternative point of departure for chlorpyrifos based on biomonitoring data from one of the chlorpyrifos epidemiology studies, but the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Scientific Advisory Panel (SAP) met on April 19-21, 2016, and recommended against this new approach. In its request for an extension, EPA stated that the FIFRA SAP might recommend a “hybrid approach” to adjusting the point of departure for AChE inhibition. The FIFRA SAP meeting minutes do not appear to include such a hybrid recommendation.
In a related development, EPA has reached an agreement with the Columbia Center for Children’s Environmental Health (CCCEH) regarding the release of raw data from one of the chlorpyrifos epidemiology studies. During the FIFRA SAP meeting, concerns were raised regarding use of the CCCEH study without access to the underlying raw data. In an April 19, 2016, letter to Dr. Linda P. Fried, Dean of the Mailman School of Public Health at Columbia University, EPA requested that CCCEH provide access to the underlying data. In her response dated May 18, 2016, Dr. Fried offered to work with EPA “to determine if we can develop one or more data sets that can be properly de-identified, consistent with our obligation to protect the privacy of our research subjects, and that will also enable EPA to conduct its own analyses in order to address its transparency goals” or, in the alternative, offered to allow EPA staff to review the original data “in a secure data enclave onsite at Columbia.” In its June 27, 2016, response, EPA stated that the offer to allow EPA staff to review the underlying data at a secure site did not resolve issues concerning the transparency of EPA’s analysis. This correspondence is available in EPA Docket ID EPA-HQ-OPP-2008-0850. While EPA maintained it is “unnecessary” for CCCEH and EPA to develop redacted data sets, EPA accepted CCCEH’s offer to develop such data sets.
EPA’s request for a six month extension was filed on June 29, 2016, two days after it accepted the offer by CCCEH to develop redacted data sets for the CCCEH epidemiology study. Moreover, the FIFRA SAP meeting minutes issued on July 20, 2016, do not appear to provide the guidance that EPA had expected concerning a potential “hybrid” approach to adjusting EPA’s proposed point of departure for AChE inhibition.
Given the lesser extension granted by the court, it is questionable whether EPA will have sufficient time to review adequately the redacted underlying data sets offered by CCCEH, or even to determine whether those redacted data sets are adequate for this review, and to make any determination based on such data before EPA issues a supplementary proposal based on the refined drinking water assessment and the updated epidemiology assessment. The court has stated that it will entertain no further extension requests, so EPA must complete its work expeditiously to allow time for comment before final action is due on March 31, 2017.
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.”
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.
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 and James V. Aidala
The U.S. Environmental Protection Agency’s (EPA) Proposal to Mitigate Exposure to Bees from Acutely Toxic Pesticide Products published in the Federal Register on May 29, 2015, seeks comment on a proposal to adopt mandatory pesticide label restrictions to protect managed bees under contract pollination services from foliar application of pesticides that are acutely toxic to bees on a contact exposure basis, unless the application is made in accordance with a government-declared public health response. These label restrictions would prohibit applications of pesticide products that EPA has identified as acutely toxic to bees, during bloom when bees are known to be present under contract.
As part of this mitigation proposal, the 48-hour notification exception for crops under contracted pollination services during bloom for all neonicotinoid product labels would be removed. These restrictions are intended to reduce the likelihood of acute exposure and mortality to managed bees under contract. EPA is not proposing at this time to require new language for pesticide labels for managed bees not under contract pollination services. This does not, however, alter EPA’s previous actions intended to impose more specific restrictions on neonicotinoid pesticides through label language addressing potential risks to bees not under contract for pollination services.
EPA is also seeking comment on a proposal to rely on efforts made by states and tribes to reduce pesticide exposures for application sites not under contracted services, through development of locally-based measures, specifically through managed pollinator protection plans. These plans would include local and customizable mitigation measures to address certain scenarios that can result in exposure to pollinators. EPA intends to monitor the success of these plans in deciding whether further label restrictions are warranted.
EPA states that if it receives evidence during the public comment period, and/or through outreach at stakeholder meetings, that the contract provisions that are the subject of the proposed rule commonly considered effective and mutually agreed upon stakeholder practices (i.e., beekeeper-to-grower) indicating that the application of acutely toxic pesticides is not of risk concern for bees under contract, then EPA will consider this information in determining whether this scenario needs the mitigation indicated in the proposed language.
EPA states that the proposed actions are consistent with the Presidential Memorandum issued in June 2014 to reduce the effect of factors that have been associated with pollinator declines in general, as well as the mandate to engage state and tribal partners in the development of pollinator protection plans. Comments on the proposal are due by June 29, 2015.
The main elements of EPA’s pesticide regulatory strategies and policies were only a small part of the response to the President last week on a National Strategy for pollinators, but now that EPA has issued this proposal, attention will turn to what EPA is more precisely planning to do with regard to proposing and implementing new restrictions on pesticides generally and/or neonicotinoid products in particular.
As expected, the focus of the proposal is on new restrictions for acutely toxic pesticide applications (defined in the notice as “pesticides with an acutely lethal dose to 50% of the bees tested of less than 11 micrograms per bee”), where the pesticide application site is also where there are contracted pollination services. Essentially, foliar application of pesticides acutely toxic to bees are prohibited where there are bee colonies present pursuant to a contract to provide pollination services. EPA’s proposal (at Appendix A) includes a long list of pesticides (over 75) that meet the acute toxicity criteria that will be subject to the new restrictions. This list includes many more pesticides than just the neonicotinoid products.
In addition, for managed bees not under contracted services, or for other “unmanaged” bees, EPA’s reliance on state “Managed Pollinator Protection Plans” (MP3s) is consistent with public statements that EPA officials and line staff have made in recent months, so there appears to be few surprises in the proposal at first glance. Some states already have plans; many are under development. EPA has worked closely with state pesticide regulatory officials on development of state plans, and signaled that it expects state plans to incorporate three core ideas: public participation in developing the plan; some kind of notification scheme to alert beekeepers of insecticide applications; and a way to evaluate whether the state plan is effective in reducing insecticide exposure to bees.
Even so, what may generate the most public comment about EPA’s proposal is what it does NOT do; for example:
- The proposal does not impose a ban on neonicotinoid pesticides as some advocacy groups have sought;
- The proposal does not require EPA approval of state management plans (MP3s);
- The proposal does suggest options for registrants to seek product-specific exemptions to what is mandated; in other words, it again seeks to impose EPA regulatory actions “by letter” using a “one size fits all” approach; and
- The proposal does not offer significantly new restrictions regarding pollinators generally, but maintains a focus on contracted honeybees and commercial pollination services.
As the proposal has just been issued, stakeholders will now review the content to look for “the devil in the details” -- and develop comments to submit during the 30-day comment period EPA offers. (It would not be surprising if the comment period on such a high profile proposal is extended.)
More information concerning the Presidential Memorandum and the national strategy are available in Bergeson & Campbell, P.C.’s (B&C®) blog post on Pollinator Health Task Force Issues National Strategy to Promote the Health of Honey Bees and Other Pollinators.
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.
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.