### Docket Number EPA-HQ-OPP-2015-0053 www
.regulations.gov



# Myclobutanil Final Work Plan Registration Review

Case Number 7006

September 2015

Approved by:

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Date: Richard P. Keigwin, 

### Jr. Director Pesticide Re-evaluation Division

### INTRODUCTION
This is the Environmental Protection Agency ' s (EPA or the Agency) Final Work Plan (FWP) for the registration review ofmyclobutanil. This work plan addresses public comments received concerning the Preliminary Work Plan (PWP), which was posted in the myclobutanil registration review docket (EPA-HQ-OPP-20 15-0053). Myclobutanil is classified as a sterol biosynthesis inhibitor (SBI) and is further classified as a demethylation inhibitor (DMI) fungicide. Myclobutanil is a member ofthe class ofcompounds known as conazole fungicides used on a variety of agricultural crops as well as on ornamentals , in home orchards , in gardens , and on turf for the control ofpowdery mildew and rust. 

### It can also be used as a cotton seed treatment.
The Agency is implementing the registration review program pursuant to Section 3(g) ofthe Federal Insecticide, Fungicide , and Rodenticide Act (FIFRA), and will review each registered pesticide every 15 years to determine whether it continues to meet the FIFRA standard for registration. Changes in science, public policy, and pesticide use practices occur over time. The registration review program is intended to make sure that, as the ability to assess risk evolves and
as policies and practices change, all registered pesticides continue to meet the statutory standard. The public phase of registration review begins when the initial docket is opened for each case. Information on this program is provided on the Agency's website. 1

The FWP begins with any updates since the Preliminary Work Plan (PWP) was issued. Next is a summary of substantive comments received during the public comment period for the PWP (concerning anticipated data needs, expected risk assessments, or the estimated timeline identified in the PWP) , and a summary of the Agency's responses to those comments. This section is followed by registration review planned data needs , risk assessments expected to be conducted, and the projected registration review timeline for myclobutanil. Lastly, there is a discussion of next steps.


### UPDATES SINCE THE PWP WAS ISSUED
Since the PWP was issued, the Agency has completed a screening ofmyclobutanil under the Agency ' s Endocrine Disrupter Screening Program (EDSP). To assist with the scientific interpretation ofthe EDSP screening results for myclobutanil and within the context of required assays , existing data from regulatory guideline studies and published literature, a weight-ofevidence (WoE) evaluation was completed. Based on the battery of Tier I screening assays , other scientifically relevant information (OSRI) suggesting potential steroidogenesis and reproductive effects reported in the fish short term reproduction assay (FSTRA) , additional Tier 2 testing under EDSP is recommended for myclobutanil. Specifically, the Medaka Extended One-Generation Reproduction Test (MEOGRT) is needed to establish dose-response relationships for assessing the potential adverse effects on fish reproduction from myclobutanil exposure. The WoE and Data Evalulation Records (DERs) for myclobutanil are available in the docket EPA-HQ-OPP-20 15-0053 available at www.regulations.gov.

1 http ://www .epa.gov/oppsrrd I / registration

**review /**  2

### SUMMARY OF COMMENTS AND AGENCY RESPONSES During the 60-day public comment period on the Myclobutanil Preliminary Work Plan, which opened on 03/30115 and closed on 05/29115, the Agency received two public comments. Comments were submitted by the FIFRA Endangered Species Task Force (FESTF) and the Center for Biological Diversity (CBD). The comments do not impact the timeline described in the PWP or the planned data requirements. In the PWP, EPA also solicited comments on the specific topics of environmental justice, water quality concerns, and trade irritants, but no comments or information were received on those issues.
This section summarize the comments made about the PWP. Public comments and EPA responses in their entirety are located in the docket, EPA-HQ

-OPP

-2015-0053, accessible at www.regulations.gov.


### Comment submitted by Center for Biological diversity in EPA-HQ-OPP-2015-0053
Comments: 

### The Center for Biological Diversity (CBD) commentsfocus on EPA's independent duty under the Endangered Species Act (ESA) to consult with the US. Fish and Wildlife Service and the National Marine and Fisheries Service (Services) on the registration review of myclobutanil. Specifically, CBD opposes the proposed decisionfor myclobutanilprior to completion of consultation with the Services. The CBD comments mention various aspects of the risk assessmentprocess, including use of the best available data to develop endangered species risk assessments, and evaluation of effects on endangered and threatened species and their designated critical habitat. CBD also expresses concern regarding the rigor of the Agency's preliminary determinations regarding the effects ofmyclobutanil on endangered and threatened (listed) species and their designated critical habitat for the myclobutanil registration review.
EPA Response: EPA has reviewed the comments from CBD on the registration review docket opening for myclobutanil and plans to address many ofthe concerns raised by CBD as part ofthe implementation plan for assessing the risks ofpesticides to listed species based on the recommendations ofthe April2013 National Academy of Sciences (NAS) report. EPA will address concerns specific to myclobutanil in connection with the development of its final registration review decision for myclobutanil.

In November 2013, EPA, the U.S. Fish and Wildlife Service, National Marine Fisheries (the Services), and USDA released a summary oftheirjoint Interim Approaches for assessing risks to listed species from pesticides. These Interim Approaches were developedjointly by the agencies in response to the NAS recommendations, and reflect a common approach to risk assessment shared by the agencies as a way of addressing scientific differences between the EPA and the Services. The NAS report outlines recommendations on specific scientific and technical issues related to the development ofpesticide risk assessments that EPA and the Services must conduct in connection with their obligations under the ESA and FIFRA

. Thejoint Interim Approaches were released prior to a stakeholder workshop held on November 15, 2013. In addition, the EPA presented the joint Interim Approaches at the December 2013 Pesticide Program Dialogue Committee (PPDC) and State-FIFRA Issues Research and Evaluation Group (SFIREG) meetings. The agencies also held a stakeholder workshop in April 32014 and October 2014 , allowing additional opportunities for stakeholders to comment on the Interim Approaches. Additional workshops are planned to enhance stakeholder involvement. As part of a phased, iterative process for developing the Interim Approaches, the agencies will also consider public comments on the Interim Approaches in connection with the development of upcoming registration review decisions. The details ofthe joint Interim Approaches are contained in the white paper, 

### Interim Approaches for National-Level Pesticide Endangered Species ActAssessments Based on the Recommendations of the National Academy of Sciences April 20I3 Report, dated November 1, 2013.
Given that the agencies are continuing to develop and work toward implementation of the Interim Approaches to assess the potential risks ofpesticides to listed species and their designated critical habitat, the ecological problem formulation supporting this Final Work Plan for Myclobutanil does not describe the specific ESA analysis, including effects determinations for specific listed species or designated critical habitat, to be conducted during registration review. In the ecological problem formulation document for myclobutanil , EPA described the screening-level risk assessment to determine the potential effects of myclobutanil on all taxa of non-target wildlife and plants, which will assume that listed species and their designated critical habitats may be present in the vicinity ofthe application ofmyclobutanil. This screening-level assessment will allow EPA to focus its future evaluations on the types of species where the potential for effects exists once the scientific methods being developed by the agencies have been fully vetted. While the agencies continue to develop a common method for ESA analysis, the planned screening-level risk assessment for the registration review of myclobutanil will describe the level ofESA analysis completed for this particular registration review case. Once the agencies have fully developed and implemented the scientific methods necessary to complete risk assessments for endangered and threatened (listed) species and their designated critical habitats , these methods will be applied to subsequent analyses for myclobutanil as part of completing this registration review.



### Comment submitted by FIFRA Endangered Species Task Force in EPA-HQ-OPP-2015- 0053
Comment: 

### FESTF identifies that Nufarm Limited, Albaugh, LLC , and Dow AgroSciences, the technical registrants for myclobutanil , are members of FESTF and are entitled to rely on species proximity data developed by FESTF in response to the Agency's endangered species requirements.
EPA Response: The Agency thanks FESTF for its comment and will consider appropriate information as it conducts registration review and makes its registration review decisions.

4PLANNED DATA NEEDS
Table 1 below summarizes the planned data needs for myclobutanil based on the 

### Registration Review Problem Formulationfor Myclobutanil , the 

### Myclobutanil: Human Health Assessment Scoping Document in Support of Registration Review, and the 

### BEAD Chemical Profile (BCP)for Registration Review: Myclobutanil (12885 7).
Based on the EDSP Tier 1 Weight of Evidence review, myclobutanil is listed for limited Tier 2 testing. The recommended MEOGRT study will be pursued separate from registration review data requirements.

Table 1: Planned Data Needs for the Myclobutanil Registration Review
Estimated Guideline Timeframe Number Study Title Test Material (Months from receipt ofDCI)
850. 10 75 Fish acute toxicity test, estuarine / marine fish or TGAI 18 fathead minnow 850.2 100 Avian oral toxicity (passerine species) TGAI 12 850. 3040 Field testingfor pollinators3 TEP 24 850.4 100 T errestrial plant toxicity: Tier II seedling emergence TEP 12 850.4 150 Terrestrial plant toxicity: Tier II vegetative vigor TEP 12 850.4400 Aquaticplant growth: Tier I I vascular plants TEP 1 2 850.4500 Aquatic Plant Growth: Tier II algae TEP 12 850.4550 Cyanobacterial toxicity TEP 1 2 Non

- H oney bee larvae chron ic oral toxicity TGAI 12 Guideline Non- Hon eybee adult chronical oral toxicity TGAI 12 Guideline Non- Hon eybee larvae acute oral toxicity TGAI 12 Guideline Non

- H oneybee adult acute oral toxicity TGAI 12 Guideline Non- Semi-field testfor pollinators (tunnel or colony TEP 24 Guideline feeding studies/ Non- Residue analysis of nectar andpollen inflowering TEP 24 Guideline crops 3 TGAI = technical grade active ingredient; TEP = typical end-use product;

2 On June 27, 2012, EPA announced certain revisions in harmonized guideline series 850

- Eco logical Effects Tests

- including renumbering and other designations or changes for some guideline studies. See "Final Test Guidelines; OCSPP 850 Series; Notice of Availability " 77 FR 38282, June 27,2012. http ://www.regulation s.gov/#! documentDetaii;D= EPA -HQ-OPPT-2009-0 154-0028 3 The need for this test is contingent upon res ults of lower tier pollinator tests

. Protocol is required for this test. 

### 5

### RISK ASSESSMENTS FOR REGISTRATION REVIEW
The most recent ecological risk assessment for myclobutanil was conducted in 2012. Myclobutanil has had several Section 18 new use assessments and a 2009 California Red-Legged Frog Endangered Species Assessment for Myclobutanil. Based on the review of available toxicity data, the Agency anticipates the need to conduct a comprehensive ecological risk assessment for myclobutanil. During registration review, the Agency will conduct a comprehensive human health risk assessment for all uses ofmyclobutanil. The most recent dietary human health risk assessment
was performed in 2007 for several food uses and the most recent occupational and residential assessment was performed in 2013 for a proposed new use on grass grown for seed, sod farms , and included an updated residential reassessment on the existing myclobutanil residential uses
. Iftoxicological endpoints or points ofdeparture (PoDs) are revised based on the required data, or ifthere are any changes or updates to the Office of Pesticide Programs ' (OPP) standard operating procedures or default exposure assumptions for risk assessment, they will also be considered in any updated human health or ecological risk assessment.
Table 2 summarizes the planned registration review risk assessments for myclobutanil.

6Table 2: Planned Ri sk Assessments for the Myclobutanil R egistration Review Typ e of Risk Assessment Conduct? Notes 

### Ecolosdcal and Environmental Fate Comprehensive ecological 

### y Based upon a review of existing ecological data and (species to be assessed anticipated data requirements , a comprehensive risk include terrestrial , aquatic and assessment is expected. endangered species) Incidents Will check for Review ofthe Agency ' s ecological incident updates databases identified a total of 4 discreet ecological incidents associated with myclobutanil (involving plants and animals).
For a discussion of reported ecological incidents for myclobutanil , see page 26 ofthe Problem Formulation

. 

### Human Health Dietary Food 

### y An updated dietary (food and drinking water) risk Drinking water y assessment will need to be conducted during registration review to incorporate the anticipated update to the drinking water assessment. Occupational Handlers (mixers , loaders , 

### y The previous occupational exposure assessments applicators) identified no risk estimates of concern, however for registration review, an occupational risk assessment will be reviewed to ensure all formulation types , possible exposure scenarios , and the most current Post-application exposure methodologies and assumptions are used.

Residential Handlers 

### y Updated residential risk assessments will be required Post-application 

### y if changes are made to the PoDs and Uncertainty Factors (UFs) used in the risk assessment.
A bystander spray drift analysis has not been conducted for myclobutanil. In accordance with new policies , potential residential post-application exposure from spray drift resulting from ground , aerial , and airblast applications must be assessed for non-granular formulated myclobutanil products. Other

7Aggregate 

### y Updated aggregate risk assessments are needed for registration review if changes are made to either the dietary and/or occupational and residential assessments.

Cumulative N The Agency has not made a common mechanism of toxicity finding as to myclobutanil and any other substances, and myclobutanil does not appear to produce a toxic metabolite produced by other substances. The Agency has not assumed that myclobutanil has a common mechanism oftoxicity with other substances. Tolerances 

### y During registration review, OPP will reevaluate the myclobutanil tolerance expression to ensure it is to ensure it is in compliance with the most recent (2009) guidance.
The U.S and Canadian residue definitions for crop , livestock, and milk commodities are not harmonized and the CODEX residue definition includes parent only. During registration review, tolerances will be harmonized where possible. Incidents Will check for For a discussion ofreported human health incidents updates for myclobutanil , see page 8 ofthe Scoping Document and 

### Myclobutanil: Tier I Review of Human Incident s document.

8

### TIMELINE
EPA has created the following estimated timeline for the completion ofthe myclobutanil registration review

. The projected timeline has not changed since the PWP.



### Table 3: Registration Review for Fluroxypyr- Projected Registration Review Timeline Activities Estimated Date Opening the Docket Open Docket and 60-day Public Comment Period 2015 MarchCompleted Close Public Comment May 2015

- Completed Case Development Final Work Plan September 2015 Issue DCI 2015 October

- December Data Submission 2017 October

- December 60-day Public Comment Period for Draft Risk Assessments4 

### 2019 April

- June Registration Review Decision 60-day Public Comment Period for Proposed Registration Review 2020 January

- Decision March Registration Review Decision and Begin Post-Decision Follow-up 2021 Total (years) 5 

### 6


### NEXT STEPS
As noted previously , the Agency plans to require several environmental fate, ecological effects and human health studies for myclobutanil through a Data Call-In (DCI) Notice, expected to be issued October 2015.

4 The regulations governing Registration Review generally require the Agency to provide a public comment period of at least 30 calendar day s for draft risk assessments ; see 40 CFR Part 155

.53(c)

. For conventional pesticides , the Agency plans to provide a 60 calendar day public comment period generall y for draft risk assessments. 5 The timeline may be affected by EDSP assessments for myc lobutanil , see http ://www.epa .gov/endo/ 

### 9