By James V. Aidala, Lisa R. Burchi, and Barbara A. Christianson

On February 25, 2022, the U.S. Environmental Protection Agency (EPA) announced it has issued a response denying the objections filed against its final rule revoking all chlorpyrifos tolerances (Response). EPA issued the August 18, 2021, final rule in response to the Ninth Circuit Court’s Order directing EPA to issue a final rule in response to Pesticide Action Network North America and Natural Resources Defense Council’s 2007 petition, which requested EPA to revoke all chlorpyrifos tolerances.

After issuing the August 2021 final rule, and consistent with the Federal Food, Drug, and Cosmetic Act (FFDCA), EPA provided an opportunity for any interested party to file an objection to any aspect of the final rule and request a hearing on those objections. Several objections were filed, with concerns ranging from the scope of the revocation of tolerances, the economic and environmental impacts of the revocation, and the implementation timeframe. EPA stated that after careful consideration, it denied all objections, hearing requests, and requests to stay the final rule filed during the period for submitting responses to the final rule.

In addition to its Response, EPA issued letters to the registrants of chlorpyrifos products with food uses confirming revocation of the tolerances and providing options for cancellation and label amendments. In particular, these options include the ability for registrants to submit registration amendments to remove food uses from product labels or submit a voluntary cancellation for products where all uses are subject to the tolerance revocation. For registrations not voluntarily cancelled, EPA stated it intends to issue a Notice of Intent to Cancel under the Federal Insecticide, Fungicide, and Rodenticide Act to cancel registered food uses of chlorpyrifos associated with the revoked tolerances. A copy of its Response and the accompanying order in the chlorpyrifos final rule docket is available at EPA-HQ-OPP-2021-0523.

EPA states that this action will be incorporated into the ongoing registration review of chlorpyrifos and it will continue to review the comments submitted on the chlorpyrifos Proposed Interim Decision, draft Revised Human Health Risk Assessment, and draft Ecological Risk Assessment. These documents are available in the chlorpyrifos registration review docket at EPA-HQ-OPP-2008-0850. After considering public comments, EPA will proceed with registration review for the remaining non-food uses.

Additional information on chlorpyrifos is available on our blog and on EPA’s website.

Commentary

It is not surprising that EPA denied all objections to its tolerance revocation decision. Since the earlier decision in 2009 to revoke the tolerances for the insecticide carbofuran, EPA, along with advocates of greater restrictions on pesticide exposures, have found a pathway for terminating pesticide uses while avoiding the significant procedural requirements of FIFRA’s cancellation provisions. The elaborate legal niceties of either approach will likely not quiet those grower groups and others who challenged EPA’s decision in this case.

Of note, in its lengthy Response (51 pages in the Federal Register, 87 Fed. Reg. 11222 (Feb. 28, 2022)), EPA again admits that some uses of chlorpyrifos on certain crops in certain areas are “high benefit” uses that can meet the required safety standards even when using EPA’s most conservative assumptions. Those eleven crop uses were among the many additional uses of the insecticide, and here EPA is explaining its case that as part of its decision, all of the uses on the current label are to be assessed together. At the point in time when EPA most recently assessed chlorpyrifos uses (the 2020 registration review Pesticide Interim Decision), some uses may have been able to meet the standard, but as explained in this notice: “In the final rule, EPA assessed aggregate exposure based on all currently registered uses of chlorpyrifos as required by the FFDCA and consistent with its guidance.”

This will likely be of little satisfaction to growers who produce those crops identified by EPA as meeting the standard.

To affected growers, the revocation of tolerances for the identified crop uses that nonetheless could meet the standard, along with the long-winded denial of objections citing the fine points of the legal procedures, amount -- to them -- as what Justice Scalia once described as “pure applesauce.” (Ironically, according to EPA’s 2020 assessment, applesauce sourced from New York and Michigan apples would have met the required standards according to EPA’s 2020 risk assessment.) Those groups may decide to continue the legal back-and-forth process for further review of the original decision and now the objection denials.

But the larger question for all registrants and pesticide users, not just chlorpyrifos, is what longer term issues are raised by EPA’s approach.

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By James V. Aidala and Lisa R. Burchi

On November 18, 2021, the United Farm Workers and several other non-governmental organizations (NGO) filed a petition with the U.S. Environmental Protection Agency (EPA) to revoke all food tolerances and cancel registrations for organophosphate (OP) pesticides (Petition). The Petition was filed pursuant to the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. Section 346a(d), the Administrative Procedure Act (APA), 5 U.S.C. Section 551, and the First Amendment Constitutional Right to Petition.

The Petition seeks final EPA actions to revoke tolerances and cancel registrations for 15 OPs by the registration review deadline of October 1, 2022.

The Petition also states that EPA must take the following actions:

• Update EPA’s human health risk assessments (HHRA) for OP pesticides to use a regulatory endpoint that the Petition claims will protect children from learning disabilities and other neurodevelopmental harm.
• Complete Endangered Species Act (ESA) consultations and ensure its registrations comply with the ESA;
• Conduct endocrine disruptor screening of all pesticides.
• Complete a cumulative risk assessment for all the OPs to address their cumulative acute poisoning and neurodevelopmental effects.

The Petition focuses on 15 OPs that are currently going through registration review:

• Acephate (EPA-HQ-OPP-2008-0915);
• Bensulide (EPA-HQ-OPP-2008-0022);
• Chlorethoxyfos (EPA-HQ-OPP-2008-0843);
• Chlorpyrifos-methyl (EPA-HQ-OPP-2010-0119);
• Diazinon (EPA-HQ-OPP-2008-0351);
• Dichlorvos (EPA-HQ-OPP-2009-0209);
• Dicrotophos (EPA-HQ-OPP-2008-0440);
• Dimethoate (EPA-HQ-OPP-2009-0059);
• Ethoprop (EPA-HQ-OPP-2008-0560);
• Malathion (EPA-HQ-OPP-2009-0317);
• Naled (EPA-HQ-OPP-2009-0053);
• Phorate (EPA-HQ-OPP-2007-0674);
• Phosmet (EPA-HQ-OPP-2009-0316);
• Terbufos (EPA-HQ-OPP-2008-0119); and
• Tribufos (EPA-HQ-OPP-2008-0883).

Commentary

Now that EPA is in receipt of the Petition, it must determine that it has received a “complete” petition to revoke a tolerance based on criteria set forth in EPA’s regulations (40. C.F.R. § 180.7). If EPA determines the Petition is complete, it will publish in the Federal Register within 30 days a notice of filing for the Petition, which must include the informative summary of the Petition submitted by the petitioner. FFDCA Section 408(d)(3). A public comment period follows.

Generally, the Petition is an important signaling document that the petitioners use to outline how EPA should approach the 2022 registration review deadline for these OP products. It signals that unless EPA completes all elements of a registration review, including a complete ESA assessment and an endocrine disruptor review -- which may be impossible for EPA to complete -- then EPA should act now to revoke OP tolerances in light of arguments contained in the Petition. It stresses the environmental justice commitments announced by the Biden Administration, arguing that evidence is clear, in their view, of the need to take immediate action to end OP use across virtually all of the members of the class. It seems to anticipate that even if EPA rolls out registration reviews of the individual OP pesticides before the deadline, there will likely be comment and debate about the specific analyses and evaluation of each member of the category. This would additionally delay the completion of any revised cumulative risk assessment for the OPs.

From the view of the petitioners, not only will EPA miss the 2022 deadline, but they also argue the evidence is sufficient now for EPA to take action to revoke tolerances for these compounds based on evidence already before EPA. Other stakeholders and EPA’s eventual analyses will dispute such conclusions, but completing registration review (as defined in the Petition) will likely be impossible to complete before next October. As a result, the Petition here suggests the template these advocacy groups will use to challenge continued registration of OP products past the 2022 deadline.

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By James V. Aidala

In early July 1996, I was returning on a flight from Amman, Jordan, wondering what kind of negotiation we in the Clinton Administration faced in completing the legislative text of what became the Food Quality Protection Act (FQPA). (I had been asked to go to Jordan to visit the Jordanian pesticide regulatory program by a friend who was a senior official at the State Department. The result of my visit may have played a very, very small role in the Middle East peace process -- but that is another story for another time).

Some weeks earlier, I had been approached by Congressional staff members whom I knew from my previous job at the Congressional Research Service (CRS) as the subject area expert on the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and pesticide regulation. I joined the Clinton Administration as a political deputy in the U.S. Environmental Protection Agency’s (EPA) Office of Prevention, Pesticides, and Toxic Substances (OPPTS, now renamed as the Office of Chemical Safety and Pollution Prevention (OCSPP)). Dr. Lynn Goldman was the Assistant Administrator who had recruited me to join the efforts to reform, that is, modernize, the Delaney Clause of the Federal Food, Drug, and Cosmetic Act (FFDCA). Over the years since it was enacted in 1958, risk assessment methods and our understanding of possible cancer risks had changed greatly.

Setting the Context

In 1989, the National Academy of Sciences issued a report on “The Delaney Paradox,” examining how the Delaney Clause ironically prevented safer new pesticides from entering the market. After an important court decision (Les v. Riley), EPA was told that even if it was undesirable public policy, the law can only be changed by Congress. As EPA went along with its work, many feared that numerous pesticides might be forced off the market even if, using modern evaluation policies, they presented little risk or were in fact safer than the alternatives.

During this time, advocacy groups were concerned that the then-current law was not protective enough of the possible risks to children’s diets. A simple way to say this is, for purposes of risk assessment: “Children are not little adults,” and supporters emphasized that dietary risk assessments by EPA should pay special attention to possible children’s risk given differences in metabolism, growth stages, and other important physiological characteristics.

This led to another National Academy of Sciences report in 1994 on “Pesticides in the Diets of Infants and Children,” which recommended that pesticide regulation include particular attention and possibly greater regulation of estimated dietary risks from pesticides. Given that the new Assistant Administrator of OPPTS was Dr. Lynn Goldman, a pediatrician, this concern was a priority for the Clinton Administration.

“The Gingrich Revolution”

A less noticed irony, but also important to the history of FQPA, is the change in party control of the House of Representatives, led by Representative Newt Gingrich (R-GA) and the “Contract with America” during the 1994 elections. Unexpectedly, the Republicans had the majority in the House for the first time in 40 years, and they elected Representative Gingrich Speaker of the House.

Much longer stories have been and will be written, but shortly after taking power in the House in January 1995, the Republicans were viewed as letting lobbyists run amok -- even suggesting amendments to environmental laws while lobbyists were sitting on the dais of Committee meetings. By the end of 1995 and going into an election year in 1996, “word was” the leadership, at least on the House Energy and Commerce Committee -- chaired by Representative Thomas Bliley (R-VA) -- was looking for a “green vote” to offset the image of an anti-environment House majority. Led by staff from the office of Chair Bliley and Representative John Dingell (D-MI), who was the senior Democrat on the Committee, a draft of a compromise bill was floated and made its way to my office at EPA.

Meantime, during the previous Congress (103rd Congress, 1993 - 1994), a team of EPA staff, led by Jim Jones (a later even more famous name in EPA pesticide regulation) of the Assistant Administrator’s office, along with staff from the Office of Pesticide Programs (OPP) and the Office of General Counsel (OGC), and staff from the U.S. Department of Agriculture (USDA) and the U.S. Food and Drug Administration (FDA) (it takes a village), had developed a Clinton Administration bill that did not gather much support during 1994. The legislation did have the core concepts of “fixing Delaney” and including the “reasonable certainty of no harm” standard, and it incorporated strong protections about possible risks from residues in the diets of infants and children.

In the new Congress (the 104th), there was some action during 1995 in the House Agriculture Committee on FIFRA issues related to antimicrobial products, minor uses of pesticides, and ways to prod the registration process to become more predictable and timely (this was before the Pesticide Registration Improvement Act (PRIA)). The FIFRA amendments were not viewed as controversial and were successfully discussed between both sides of the aisle (the Agriculture Committees were much more bipartisan in those days). By itself, that package was not likely to make it through the legislative gauntlet, given the shift in political power on the Hill.

Also in 1995, Carol Browner (the EPA Administrator) cautioned us that successful bipartisan legislation was unlikely, so not much effort should be invested, given other priorities.

The key event came in the late spring of 1996, when we first saw a draft of the legislation floated by the staff of Representatives Bliley and Dingell. It was far from perfect, but it included the core elements of what the Administration had proposed in the previous Congress. Since that earlier bill had been drafted with the coordination of EPA, FDA, and USDA, if it had the essential ingredients, we thought it might be a viable vehicle for further discussion. We also sought comment from some of the influential environmental groups that had been disappointed in the Administration’s legislation in the previous Congress. Suffice it to say, inclusion of the core elements of a tough standard (reasonable certainty of no harm) and special protections regarding children’s diets made the proposals a “possible” vehicle for further discussion.

We also started to have discussions with the staff of Representative Waxman (D-CA) in the House and Senator Kennedy (D-MA). Representative Waxman was the ranking Democrat on the Energy and Commerce Subcommittee, and Senator Kennedy was the ranking Democrat on the Labor Committee, which had jurisdiction over the FFDCA.

Back to July 1996

To shorten the story, we had intense, long meetings with the various interested parties -- pesticide registrants; environmental groups; trade associations; agency staff at EPA, FDA, and USDA; Congressional staff from the authorizing Committees; and Administration leaders within the agencies and the White House. In an amazingly short time, we came to agreement over the text, which is now FQPA. Representatives Waxman and Roberts (R-KS -- Chair of the House Agriculture Committee) held a press event about the historic compromise -- even more historic since the two Representatives rarely agreed on significant legislation. Their joint endorsement and statement of support signaled to members of both parties on both sides of Capitol Hill that this was an unusual, and important, compromise. The Congressional staff then recognized the next hurdle: the August recess was approaching fast, and if not enacted into law by then, the delay could be fatal, or at least make matters more complicated, as the multitude of interest groups would likely pick apart and want further changes to the agreement that had been reached. So the rush was on to get the “green vote” to the floor of the House and Senate.

Some last-moment hiccups took a little more time. Senator Lugar (R-IN), the Senate Agriculture Committee Chair, wanted a hearing to at least review the legislation. This was not a huge hurdle, but finding time on the floor was a race against the clock before the August recess. The House was the first to vote on July 23, 1996. The bill was approved with a surprising unanimous roll call vote in the majority Republican House (the vote was 417-0 with 16 not voting). Unanimous bipartisan support! -- imagine that in today’s world.

Then, with a sprinkling of clarifying (that is, reassuring) pieces of correspondence, the Senate agreed to the House legislation under unanimous consent. (In fact, for any trivia nuts out there, if you watch the C-SPAN video of how long the Senate deliberation lasted at the end of the day on July 24, 1996 -- the request for unanimous consent and agreement clocks in under 30 seconds.)

So with unanimous support in both the House and the Senate, FQPA was approved.

One Last Step

One very important last step was needed before FQPA became law -- the President needed to sign the legislation. That happened at the White House when H.R. 1627 was signed by President Clinton on August 3, 1996.

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By James V. Aidala, Lisa R. Burchi, and Barbara A. Christianson

On August 18, 2021, the U.S. Environmental Protection Agency (EPA) announced that it will stop the use of the pesticide chlorpyrifos on all food. In the pre-publication of the Federal Register notice released on August 19, 2021, EPA revoked all “tolerances” for chlorpyrifos, which establish an amount of a pesticide that is allowed on food. In addition, EPA states that it will issue a Notice of Intent to Cancel under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) to cancel registered food uses of chlorpyrifos associated with the revoked tolerances. EPA has stated the cancellation order will follow in approximately six months after the tolerance revocations.

EPA’s announcement responds to the Ninth Circuit’s order, issued on April 29, 2021, that vacated EPA orders issued in 2017 and 2019 denying a 2007 petition filed by Pesticide Action Network North America and Natural Resources Defense Council. That petition requested that EPA revoke all chlorpyrifos tolerances, or the maximum allowed residue levels in food, because those tolerances were not safe, in part due to the potential for neurodevelopmental effects in children. The 2017 and 2019 orders denying the 2007 petition were challenged in the Ninth Circuit by a coalition of farmworker, health, environmental, and other groups.

In its order, the Ninth Circuit found that “...EPA had abdicated its statutory duty under the Federal Food, Drug and Cosmetic Act (FFDCA) ...” to “conclude, to the statutorily required standard of reasonable certainty, that the present tolerances caused no harm.” After vacating the 2017 and 2019 orders, the court remanded the matter to EPA with instructions to: “(1) grant the 2007 Petition; (2) issue a final regulation within 60 days following issuance of the mandate that either (a) revokes all chlorpyrifos tolerances or (b) modifies chlorpyrifos tolerances and simultaneously certifies that, with the tolerances so modified, the EPA ‘has determined that there is a reasonable certainty that no harm will result from aggregate exposure to the pesticide chemical residue, including all anticipated dietary exposures and all other exposures for which there is reliable information,’ including for ‘infants and children’; and (3) modify or cancel related FIFRA registrations for food use in a timely fashion consistent with the requirements of 21 U.S.C. § 346a(a)(1).”

In its announcement, EPA states that it has determined that the current aggregate exposures from the use of chlorpyrifos do not meet the legally required safety standard that there is a reasonable certainty that no harm will result from such exposures. Chlorpyrifos is an organophosphate insecticide used for a large variety of agricultural uses and has been continually reviewed with regard to potential adverse effects, including possible neurological effects in children, which has been the subject of considerable controversy for many years. EPA’s announcement notes that a number of other countries, including the European Union and Canada, and some states, including California, Hawaii, New York, Maryland, and Oregon, have taken similar action to restrict the use of this pesticide on food.

EPA states its action also will be incorporated into the ongoing registration review for chlorpyrifos. EPA is continuing to review the comments submitted on the chlorpyrifos proposed interim decision, draft revised human health risk assessment, and draft ecological risk assessment. These documents are available in the chlorpyrifos registration review docket EPA-HQ-OPP-2008-0850 at www.regulations.gov and a discussion of these issues is available on our blog here.

After considering public comments, EPA will proceed with its registration review of the remaining non-food uses of chlorpyrifos by issuing the interim decision, which may consider additional measures to reduce human health and ecological risks.

Commentary

Separate from any issues of science, evidence, or interpretation, the FFDCA’s channels of trade provision is designed to address what happens if EPA cancels a pesticide product for not meeting Food Quality Protection Act (FQPA) standards and then revokes the tolerance. EPA’s initial description of its decision was unclear on this important point regarding the status of food already in the channels of trade that may contain chlorpyrifos residues.

EPA statements at an August 18, 2021, phone briefing with agricultural stakeholders appeared to present a position that the tolerance revocations would be in effect immediately upon publication in the Federal Register. This implied that there may be an immediate revocation of the tolerances before any parallel action to cancel the associated pesticide registrations. The pre-publication version of the notice clarified that the revocation of chlorpyrifos tolerances would not become effective until six months after the publication of the notice in the Federal Register.  As of August 24, 2021, the notice has not been published in the Federal Register.

This revocation delay of six months aligns with the statement also made by EPA to cancel the registration of chlorpyrifos food use products six months after the revocation notice. EPA may face questions from some of the groups that have been advocating for this type of EPA action concerning why, if these tolerances need to be revoked, the use of the pesticide will continue in effect for the remainder of this growing season. Ed Messina, Office Director of the Office of Pesticide Programs, made a glancing reference to this at the phone conference when he stated EPA and the U.S. Food and Drug Administration (FDA) are “having discussions.” 

According to EPA, use of chlorpyrifos has been in decline due to restrictions at the state level and reduced production. EPA also notes that some alternatives have been registered in recent years for most crops, other chemistries and insect growth regulators are available for certain target pests, and that EPA is committed to reviewing replacements for and alternatives to chlorpyrifos. Some growers, however, are using registered chlorpyrifos products on food crops and hoped to be able to continue certain uses. 

EPA states in the pre-publication notice that some uses in certain areas appear to be able to meet the FQPA standard as evaluated in its 2016 and 2020 risk assessment documents, even if including the full 10x FQPA “extra” safety factor (these assessments are the reference documents EPA cites in its revocation notice). EPA further states that the Ninth Circuit’s order did not provide EPA with time to consider further changes to the use patterns or label restrictions to align with such changes hinted at in the revocation notice, and so EPA is issuing the revocation decision now. This begs the question of whether EPA might consider some continued uses in the future, although even considering any “new” tolerance would be very controversial.

In addition, none of the current actions affect (for now) the tolerances for stored grains using the sister chemical (chlorpyrifos-methyl) with a similar toxicological profile. There also are non-food use applications of chlorpyrifos, for example, mosquito control application of chlorpyrifos sprayed over a large area, that are not affected by the tolerance revocation.

This mix of messages may not be easy to explain to users and the consuming public. 

Issues regarding the timing of the revocations and continued uses are also likely to present challenges for FDA. For example, there are various blended commodities (e.g., animal feed grain, possibly co-mingling harvests from different times) where FDA may be unable to determine what part of any enforcement sample came from a particular date of use.

The orderly transition for treated commodities was designed to avoid public and grower confusion that characterized the episodes of StarLink corn chaos in 2000 or the Cheerios contamination incident in 1994 involving a reported over 100 million boxes of cereal that were eventually destroyed. EPA cites international trade obligations as another reason for the coordinated actions effective in six months to notify foreign trading partners with a “reasonable interval” for adjusting to a changed regulatory situation.

Additional information on chlorpyrifos is available on our blog.

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

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

Background

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

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

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

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

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

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

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

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

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

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

Commentary

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

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

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

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By Lara A. Hall, MS, RQAP-GLP, Jane S. Vergnes, Ph.D., DABT®, and Lisa M. Campbell
 
On Tuesday, August 25, 2015, in a Federal Register notice, the U.S. Environmental Protection Agency (EPA) announced the addition of three Office of Chemical Safety and Pollution Prevention (OCSPP) final test guidelines to its 890 Series, entitled “Endocrine Disruptor Screening Program Test Guidelines,” as follows:

• Medaka Extended One Generation Reproduction Test (MEOGRT), OCSPP Test Guideline 890.2200;
• Larval Amphibian Growth and Development Assay (LAGDA), OCSPP Test Guideline 890.2300; and
• Avian Two-generation Toxicity Test in the Japanese Quail (JQTT), OCSPP Test Guideline 890.2100.

These test guidelines are part of a series of test guidelines established by OCSPP for use in developing data on potentially adverse effects of pesticides and chemical substances on the endocrine system for submission to EPA under the Federal Food, Drug, and Cosmetic Act (FFDCA) section 408 (21 U.S.C. 346a), the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) (7 U.S.C. 136, et seq.), and the Toxic Substances Control Act (TSCA) (15 U.S.C. 2601, et seq.).  These final guidelines have been revised based on public comments received following the release of draft test guidelines in January 2015, existing EPA test guidelines, and concurrent Organisation for Economic Co-operation and Development (OECD) test guidelines. 
 
EPA worked with OECD to harmonize test guidelines for MEOGRT and LAGDA.  The specific OECD Guidelines for the Testing of Chemicals, Section 2, that apply to MEOGRT and LAGDA, are available here.  Substantive changes reflected in the final OCSPP MEOGRT and LAGDA test guidelines include:
 
1.         The test will end following hatching of the second generation (F2) offspring.  The option for extending the MEOGRT through reproduction by the F2 generation has been removed from the final test guideline pending additional data. This is consistent with the decision made in the draft OECD test guideline for MEOGRT. This test guideline may be updated as new information and data are considered. For example, guidance on extending the F2 generation through reproduction may be potentially useful under certain circumstances (e.g., chemicals with high bioconcentration potential or indications of trans-generational effects in other taxa).
 
2.         The mean water temperature over the duration of the MEOGRT has been changed to 25 ± 2 °C to be consistent with the analogous OECD test guideline.
 
3.         The LAGDA developmental stage terminology has been clarified to avoid confusion with what is meant by complete metamorphosis.
 
4.         An effort was made to clarify and provide more explicit guidance as to what specific histopathology is appropriate based on the results of the study, e.g., the conduct of liver and kidney histopathology in the MEOGRT and LAGDA test guidelines with respect to overt toxicity.
 
5.         The rationale for use of solvent control only, dilution water control only, or pooled controls in the statistical analyses for the MEOGRT and LAGDA was clarified.
 
6.         The guidelines have been modified to address commenters' concerns that they be more flexible and less prescriptive. Examples have been provided as appropriate to add clarity. 
 
The JQTT draft test guideline (OCSPP 890.2100) was revised to address comments provided by the public, the draft OECD test guideline for the avian two-generation toxicity test in the Japanese quail, as well as the existing EPA test guidelines and OECD test guidelines for avian one-generation toxicity tests.
 
EPA revised the terminology, procedures, endpoints measured, figures, tables, and appendices in the JQTT test guideline to clarify specific points raised by public commenters, and to address commenters' concerns that they be more flexible and less prescriptive, as follows:

1.         The revised test guideline includes fewer endpoints.  For example, the revisions eliminated behavioral endpoints to reduce the overall numbers of birds required for the study; eliminated endpoints that are difficult to obtain (i.e., hormone levels measured in embryo blood samples); and eliminated redundant endpoints and statistical analyses.
 
2.         For clarity, the test terminates with measurement of the 14-day survival of the F2 generation chicks.  This is the minimum length of the study necessary to evaluate and measure a chemical's effect on the first generation’s (F1) reproductive performance.  If delayed reproduction is observed in F1 birds, a decision to extend the F2 generation may be made.  If extended, the test should be terminated when F2 birds are approximately 6 weeks old, when 90 percent of control animals have reached sexual maturity.  The decision to limit the length of the JQTT is consistent with EPA's efforts to move to extended one-generation reproduction test protocols for Tier 2 testing rather than require multigenerational studies.  Extended one-generation reproduction tests are scientifically justified in many cases, reduce the use of animals in testing, and reduce costs.

Electronic access to OCSPP test methods and guidelines is available here.
 
The release of these final testing guidelines marks another significant step in the overall Endocrine Disruptor Screening Program (EDSP), making way for the anticipated Tier 2 testing phase with the List 1 chemicals.  EPA recently released Tier 1 weight-of-evidence assessments for List 1 substances in the EDSP and registrants are now receiving the associated data evaluation records (DER) for the Tier 1 screening studies.  The purpose of the Tier 1 screening was to identify potential interactions with three hormonal pathways (estrogen, androgen and thyroid) in the endocrine system.  As a result of the  potential interactions with one or more of these pathways observed, EPA has recommended Tier 2, multigenerational studies across various species for 18 of the 52 List 1 chemicals, including the MEOGRTS (13 chemicals) and LAGDA (5 chemicals).  Test Orders for Tier 2 studies will be issued following completion of the Information Collection Request (ICR) process within the Office of Management and Budget (OMB).  The public review and comment period for this ICR concludes on September 2, 2015, with a response from OMB to follow in early October 2015.  In the interim, registrants are closely reviewing their respective assessments and DERs, and industry groups are assessing the approach employed by EPA in these Tier 1 assessments, including but not limited to, the statistical reanalysis of study data and conclusions drawn by EPA.

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