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I NTRODUCTION

This is the Environm ental Protection Agency’s (EPA or the Agency ) Final Work Plan (FWP) for the registration review of topramezone . This work plan addresses public comments received concerning the Preliminary Work Plan (PWP) , which was posted in the topramezone registration review docket (EPA

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- 0127 ). Topramezone is a broad

- spectrum systemic herbicide registered for use to control broadleaf and certain grass weeds. The mode of action in plants is
inhibition of the 4

- hydroxyphenylpyruvate dioxygenase ( HPPD ) enzyme

. Topramezone is currently registered for use on corn, non

- cropped areas, residential and non

- residential turf g rass, and aquatic use sites.

The Agency is implementing the registration review program pursuant to Section 3(g) of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), and will review each registered pesticide every 15 years to determine whether it continues to meet the F IFRA 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.
Informatio n on this program is provided on the Agency’s website

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The FWP begins with any update s since the 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 response s to th o se comments

. This section is followed by registration
review planned data needs, risk assessments expected to be conducted , and the projected registration review timeline for topramezone

. Lastly, there is a discussion of nex t steps.

UPDATES SINCE THE PWP WAS ISSUED

A petition was submitted in November 2015 by technical registrant BASF for the use of topramezone on sugarcane . The petition is under review by the Registration Division.

The topramezone registration review data needs table has been revised by updating the timeframes of the “ Semi

- field testing for pollinators (tunnel or colony feeding studies) (Tier 2)” and “Field trial of residues in pollen and nectar (Tier 2)” studies from 12 to 24 months.

SUMMARY OF COMMENTS AND AGENCY RESPONSES

During the 60

- day public comment period on the topramezone Preliminary Work Plan , which opened on October 2, 2015 and closed on December 1, 2015 , the Agency received 2 public comments. Comments were submitted by FIFRA Endangered Species Task Force (FESTF) and the Center for Biological Diversity

. The comments do not address the timeline described in the PWP, but they do address the planned ecological and human health risk assessments and data requirements. In the PWP, EPA also so licited comments on the specific topics of environmental

1 http://www2.epa.gov/pesticide

- reevaluation3

justice, water quality concerns , and trade irritants, but no comments or information were received
on those issues.

Below are summaries of the public comments and the EPA responses in their entirety

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Comments submitted by the FIFRA Endangered Species Task Force (FESTF) in EPA

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1. Comment 1 : The FIFRA Endangered Species Task Force (FESTF) submitted a comment informing the Agency that topramezone technical registrants AMVAC an d BASF are FESTF members and are entitled to rely on FESTF data.

EPA Response 1 : The Agency thanks FESTF for its comment and will take this under
consideration.

Comments submitted by the Center for Biological Diversity in EPA

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Comment : The Center for Biological Diversity’s (CBD) comments focus on the EPA’s duty to consult with the U.S. Fish and Wildlife Service and the National Marine Fisheries Service (the Services) on the registration review of topramezone in accordance with the Endangered Species Act (ESA). The CBD comments mention various aspects of the risk assessment process, 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 of topramezone on endangered and threatened (listed) species and their designated critical habitat for the topramezone registration review.

Response : EPA has reviewed the comments from CBD on the registration review docket opening for topramezone and plans to address many of the concerns raised by CBD as part of the implementation plan for assessing the risks of pesticides to listed species based on the recommendations of the April 2013 National Academy of Sciences (NAS) report. EPA will address concerns specific to topramezone in connection with the development of i ts final registration review decision for topramezone

. In November 2013, the EPA, along with the Services and the USDA, released a summary of their joint Interim Approaches for assessing risks to endangered and threatened (listed) species from pesticides. The Interim Approaches were developed jointly by the agencies in response to the National Academy of Sciences’ (NAS) recommendations and reflect a common approach to risk assessment shared by the agencies as a way of addressing scientific differences bet ween the

EPA and the Services. The NAS report 2 outlines recommendations on specific scientific and technical issues related to the development of pesticide risk assessments that EPA and the Services must conduct in connection with their obligations under the ESA and FIFRA.

2 http://www.nap.edu/catalog/18344/assessing

- risks

- to

- endangered

- and

- threatened

- species

- from

- pesticides4

The joint 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 Stat e

- FIFRA Issues Research and Evaluation Group ( SFIREG) meetings. The agencies also held a stakeholder workshops in April 2014 and October 2014, allowing additional opportunities for stakeholders to comment on the Interim Approaches. Additional workshops ar e 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 Registrati on Review decisions. The details of the joint Interim Approaches are contained in the white paper 3 “Interim Approaches for National

- Level Pesticide Endangered Species Act Assessments Based on the Recommendations of the National Academy of Sciences April 2013 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 of pesticides to listed species and their designated critical habitat, the eco logical problem formulation supporting this Final Work Plan

for topramezone 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 topramezone , EPA described the screening

- level risk assessment to determine the potential effects of topramezone 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 of the application of topramezone

. This screening

- level

assessment will allow EPA to focus its futu re 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 topramezone will describe the level of ESA analysis completed for this particular registration review case. Once the agencies have fully developed and implemented the scientific methods necessary to com plete risk assessments for endangered and threatened (listed) species and their designated critical habitats, these methods will be applied to subsequent analyses for topramezone as part of completing this registration review.

3 http://www.epa.gov/endangered

- species5

PLANNED DATA NEEDS

Table 1 below summarizes the planned data needs for topramezone based on the Problem Formulation for the Ecological Risk and Drinking Water Exposure Assessments to be Conducted for the Registration Review for Topramezone

, August 26, 2015 and Topramezone. Human

- Health Assessment Scoping Document in Support of Registration Review, July 10, 2015

. The planned data needs have not changed from what was included in the PWP

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Table 1: Planned D ata Needs for the Topramezone Registration Review

Guideline
Number 4 Study Title 4 Test
Material Estimated

Timeframe
(Months from receipt of DCI)

850.2100 Avian oral toxicity (passerine species) TGAI 12

850.2300 Avian reproduction study (mallard) TGAI 24

850.3040 Field testing for pollinators (Tier 3) 5 TEP 24

850.4500 Algal toxicity study TEP 12

850.6100 Environmental chemistry methods/independent

laboratory validations in soil, water 6 TGAI 12

Non

guideline (OECD TG237) Acute oral toxicity to larval honey bees (Tier 1) TGAI 12

Non

guideline Chronic oral toxicity to adult honey bees (Tier 1) TGAI 12

Non

guideline Chronic oral toxicity to larval honey bees (Tier 1) TGAI 12

Non

guideline Semi

- field testing for pollinators (tunnel or colony

feeding studies) (Tier 2) 5 TEP 24

Non

guideline Field trial of residues in pollen and nectar (Tier 2) 5 TEP 24

TGAI = technical grade active ingredient; TEP = typical end

- use product ;

4 On June 27, 2012, EPA announced certain revisions in harmonized gui deline series 850

– Ecological 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.regulations.gov/#!documentDetail;D=EPA

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5 Study may be waived depending on results of Tier 1 pollinator studies.

6 ECM/ILV needed for soil. Only the ILV is needed for water.6

RISK ASSESSMENTS FOR REGISTRATION REVIEW

During registration review, t he Agency will conduct a comprehensive ecological risk assessment, including an endangered species assessment, for all uses of topramezone. For human health,
EPA will conduct revised occupational handler and post

- application risk assessments during registration review. If toxicological endpoints or points of departure are revised based on the data that are required for registration review, they will be considered in the new assessments, as well as any changes to the standard operating procedures or default exposure assu mptions.

Table 2 below summarizes the planned registration review risk assessments based on the EFED
Problem Formulation and HED Scoping Document . T he planned assessments have not changed
from what was included in the PWP

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Table 2 : Planned Assessments for the Topramezone Registration Review

Type of Risk Assessment Conduct? Notes
Ecological and Environmental Fate Comprehensive ecological (species to be assessed include terrestrial and aquatic organisms), including endangered species Y Both topramezone and environmental transformation products are considered the stressors of concern. EFED will use a total toxic residue (TTR) approach, which is based on the assumption that the transformation products are of equal toxicity to the
assessed organisms tested with the parent compound.
The TTRs are defined as t opramezone, M670H05, M670H01, and M670H10 for all taxa except plants. For plants, M670H05 is excluded.
Incidents Will check for updates For a discussion of reported ecological incidents for

topramezone, see page 24 of the Problem
Formulation.

Human Health Dietary
Food N A new dietary exposure assessment is not anticipated to be needed during Registration Review unless there

are significant increases to the drinking water exposure estimates and/or there are updates to the toxicity endpoints or safety factors. Drinking water N A new dietary exposure assessment is not anticipated to be needed during Registration Review unless there are significant increases to the drinking water exposure estimates and/or there are updates to the toxicity endpoints or safety factors. Occupational Handlers (mixers, loaders, applicators) Y Updated occupational handler exposure assessments
will be conducted during Registration Review for topramezone use on corn ; all other exposure scenarios
will be re

- evaluated if there are changes in the toxicity endpoints or safety factors.

Post

- application Y Updated occupational post

- application exposure

asses sments will be conducted during Registration Review for topramezone use on corn ; all other exposure scenarios will be re

- evaluated if there are changes in the toxicity endpoints or safety factors.
Residential
Handlers N New residential handler exposure and risk assessments are not anticipated to be needed during Registration Review unless there are updates to the toxicity endpoints or safety factors.8

Post

- application N New post

- application residential exposure and risk assessments are not anticipated to be needed during Registration Review unless there are updates to the toxicity endpoints or safety factors

. Drift/Volatilization Y The Agency will examine the need f or a volatilization

assessment as well as evaluate the potential topramezone exposure from spray drift during Registration Review.
Other Aggregate N N ew aggregate assessments are not anticipated to be needed during Registration Review, unless there are changes in uses, procedures, drinking water exposure estimates, toxicity endpoints, and/or safety factors.
Cumulative N The Agency has sought additional information from registrants regarding the mode of action/adverse outcome pathway (MOA/AOP) for HPPD inhibiting chemicals. Submitted data are currently un der review
and will be used to evaluate the need for a cumulative assessment as part of Registration Review.
Tolerances N
Incidents Will check for updates For a discussion of reported human incidents for

topramezone see page 9 of the Scoping Document an d
the Topramezone: Tier I Review of Human Incidents. July 30, 2015

TIMELINE

EPA has created the following estimated timeline for the completion of the topramezone registration review in Table 3 below

. The projected timeline has not changed since the PWP.

Table 3 : Projected Topramezone Registration Review Timeline

Activities Estimated Date Opening the Docket Open Docket and 60

- day Public Comment Period October 2015

– Completed
Close Public Comment December 2015

- Completed Case Development
Final Work Plan February 2016

- Completed
Issue DCI April

– June 2016
Data Submission April

– June 2018
60

- day Public Comment Period for Draft Risk
Assessments 7 Oct.

– Dec. 2019

Registration Review Decision

7 The regulations governing Registration Review generally require the Agency to provide a public comment period of at least 30 calendar days for draft risk assessments; see 40 CFR Part 155.53(c). For conventional pesticides, t he Agency plans to provide a 60 calendar day public comment period generally for draft risk assessment s

.9 Table 3 : Projected Topramezone Registration Review Timeline

Activities Estimated Date
60

- day Public Comment Period for Proposed Registration Review Decision July

- Sept. 2020

Registration Review Decision and Begin Post

- Decision
Follow

- up 2021

Total (years) 6

NEXT STEPS

As noted previously, the Agency plans to requ ire several environmental fate and ecological
effects studies for topramezone through a D ata C all

- I n Notice , expected to be issued in 2016

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