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INTRODUCTION

This is the Environmental Protection agency’s (EPA or the agency) Final Work Plan (FWP) for 

the registration review of sethoxydim. This work plan addresses public comments received 

concerning the Preliminary Work Plan (PWP), which was posted in the sethoxydim registration 

review docket (EPA-HQ-OPP-2015-0088). Sethoxydim is a post-emergent annual and perennial 

herbicide registered for use against grass weeds in broadleaf crops. Sethoxydim is registered for use 

in or on agricultural crops (including various grains, fruits, tree nuts, vegetables, and herbs), 

ornamentals, rights-of-ways, recreational areas, buildings and non-agricultural sites

The EPA 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 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.

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The FWP begins with any updates 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 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 sethoxydim. Lastly, there is a discussion of next steps.

UPDATES SINCE THE PWP WAS ISSUED

Since the issuance of the PWP, the EPA completed new use actions for certain sethoxydim 

registrations (7969-56 and 7969-58). On June 15, 2015 a final rule was posted to the Federal 

Register (FRL-9928-20) which established new and amended certain existing tolerances for 

sethoxydim. Additional information pertaining to this action can be found at

www.regulations.gov in docket number EPA-HQ-OPP-2014-0161-0005.

SUMMARY OF COMMENTS AND AGENCY RESPONSES

During the 60-day public comment period on the sethoxydim PWP, which opened on March 30, 

2015 and closed on May 29, 2015, the EPA received three public comments. Comments were 

submitted by BASF Corporation, Center for Biological Diversity (CBD), and the FIFRA

Endangered Species Task Force (FESTF), none of the comments received affected the 

anticipated registration review data needs, risk assessments, or timeline. 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.

 1 http://www.epa.gov/oppsrrd1/registration_review/
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This section only contains a summary of comments received. Full comments, and EPA’s 

response memorandum, “EFED Response to Public Comments Regarding the Registration 

Review Problem Formulation for Sethoxydim” dated July 23, 2015 are located in the docket, 

EPA-HQ-OPP-2015-0088, accessible at www.regulations.gov. 

Comments submitted by BASF Corporation in EPA-HQ-OPP-2015-0088-0012/13.

1. Comment: BASF comments were associated with the agency’s finding that sethoxydim is 

“moderately toxic” to bees based on an existing study (MRID 41510607). Furthermore, 

BASF’s comment also requested that the EPA remove sethoxydim from Appendix A of 

“EPA’s Proposal to Mitigate Exposure to Bees from Acutely Toxic Pesticide Products”

dated May 28, 2015.

Response: BASF’s intent to conduct and submit pollinator data is consistent with the 

agency’s anticipated data needs for sethoxydim. As indicated in the problem formulation, 

the need for higher tier pollinator studies is contingent upon lower tier studies. However,

sethoxydim will maintain its current classification as “moderately toxic” to bees until new 

data are submitted and evaluated. The EPA will address the inclusion of sethoxydim in 

Appendix A of “EPA’s Proposal to Mitigate Exposure to Bees from Acutely Toxic Pesticide 

Products” dated May 28, 2015 by assessing effects associated with the acute risk mitigation 

strategy (see http://www2.epa.gov/pollinator-protection/proposal-protect-bees-acutely-toxicpesticides ).

Comments submitted by Center for Biological Diversity in EPA-HQ-OPP-2015-0088-0011.

2. 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 sethoxydim 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 expressed concern regarding the rigor of the EPA’s 

preliminary determinations regarding the effects of sethoxydim on endangered and 

threatened (listed) species and their designated critical habitat for the sethoxydim

registration review.

Response: EPA has reviewed the comments from CBD on the registration review docket 

opening for sethoxydim 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 sethoxydim in connection with the development of its final 

registration review decision for sethoxydim.

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 
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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 of pesticide risk 

assessments that EPA and the Services must conduct in connection with their obligations 

under the ESA and FIFRA. 

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 State-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 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 of the joint Interim Approaches are contained in the white paper

“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 ecological problem formulation supporting this Final Work 

Plan for sethoxydim 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 sethoxydim, 

EPA described the screening-level risk assessment to determine the potential effects of 

sethoxydim 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 sethoxydim. 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 sethoxydim 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 complete risk assessments 

for endangered and threatened (listed) species and their designated critical habitats, these 

methods will be applied to subsequent analyses for sethoxydim as part of completing this 

registration review.

Comments submitted by FESTF in EPA-HQ-OPP-2015-0088-0010.

1. Comment: The FESTF comment indicated that specific registrants including the technical 

registrants of sethoxydim (Nufarm and BASF Corporation) are current members of FESTF, and 

as such, are entitled to the FESTF data on federally-listed threatened and endangered species. 
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Response: The Agency thanks FESTF for their comment and will consider the appropriate 

information at the time of the endangered species assessment.

PLANNED DATA NEEDS

Table 1 below summarizes the planned data needs for sethoxydim based on the Registration 

Review Problem Formulation for Sethoxydim (dated March 6, 2015). The planned data needs 

have not changed from what was included in the PWP.

able 1: Planned Data Needs for the Sethoxydim Registration Review

Guideline 

Number2 Study Title2 Test 

Material

Estimated 

Timeframe

(Months from 

receipt of DCI)

Anticipated Data Needs for the Parent Sethoxydim

850.1300 Aquatic invertebrate life cycle (freshwater) TGAI 12

850.1350 Aquatic invertebrate life cycle (saltwater) TGAI 12

850.1400 Fish early-life stage (saltwater) TGAI 12

850.2100 Avian oral toxicity (passerine species) TGAI 12

850.3040 Field testing for pollinators TEP 24

850.3030 Honey bee toxicity of residues on foliage TEP 12 

850.4100 Seedling Emergence (Tier I/II) TEP 12

850.4150 Vegetative Vigor (Tier I/II) TEP 12

Non-guideline Semi-field testing for pollinators TEP 24

Non-guideline Acute oral toxicity to adult bees TGAI 12 

Non-guideline Acute oral toxicity to larval honey bees TGAI 12 

Non-guideline Chronic oral toxicity to adult honey bees TGAI 12

Non-guideline Chronic oral toxicity to larval honey bees TGAI 12

Non-guideline Field trial of residues in pollen and nectar TEP 24

Anticipated Data Needs for Sulfone (the Terminal Degradate, M2-SO2)

Non-guideline Aquatic vascular plant toxicity study with a grass 

species DEG 12

TGAI = technical grade active ingredient; TEP = typical end-use product; DEG = degradate

 2 On June 27, 2012, EPA announced certain revisions in harmonized guideline 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-HQ-OPPT-2009-0154-0028
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RISK ASSESSMENTS FOR REGISTRATION REVIEW

During registration review, the EPA will conduct a comprehensive ecological risk assessment, 

including an endangered species assessment, for all uses of sethoxydim. For human health, the 

EPA recently completed a complete risk assessment in connection with a recent sethoxydim 

action (see FRL-9928-20). The risk assessment completed in connection with this action 

incorporates the most recent review of the human health toxicity and exposure data base, and upto-date assumptions and methodologies. Based upon this, at this time, the EPA does not 

anticipate conducting a new human health risk assessment for sethoxydim for registration 

review.

Table 2 below summarizes the planned registration review risk assessments based on the EFED 

Problem Formulation and recent HED Scoping/Risk assessment document. The planned

assessment for sethoxydim has not changed from what was identified in the PWP.
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Table 2: Planned Risk Assessments for the Sethoxydim 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 The agency anticipates conducting a quantitative 

ecological risk assessment for all registered 

sethoxydim uses.

Incidents Will check for 

updates

For a discussion of reported ecological incidents for 

sethoxydim, see page 25 of the Problem Formulation.

Human Health

Dietary

Food N A dietary analysis (food and drinking water) was 

completed as part of the scoping exercise/new use risk 

assessment for sethoxydim and no additional dietary 

analysis is anticipated for registration review. 

Drinking water N

Occupational

Handlers (mixers, loaders, 

applicators)

N An occupational analysis was completed as part of the 

scoping/new use risk assessment for sethoxydim and 

no additional occupational analysis is anticipated for 

registration review. 

Post-application N

Residential

Handlers N A residential analysis was completed as part of the 

scoping/new use risk assessment for sethoxydim and 

no additional occupational analysis is anticipated for 

registration review. 

Post-application N

Other

Aggregate N Aggregate analyses were completed as part of the 

scoping/new use risk assessment for sethoxydim and 

no additional aggregate analysis are anticipated for 

registration review. 

Cumulative N Unlike other pesticides for which EPA has followed a 

cumulative risk approach based on a common 

mechanism of toxicity, EPA has not made a common 

mechanism of toxicity finding as to sethoxydim and 

any other substances.

Tolerances N Currently, there are no Mexican or Codex MRLs for 

sethoxydim. Canadian MRLs and U.S. tolerances are 

currently harmonized to the extent possible. 

Incidents Yes The EPA has completed a human health incidents 

report for registration review. For a discussion of 

reported human incidents for sethoxydim, see the 

Sethoxydim: Tier I Review of Human Incidents dated 

October 23, 2014 at www.regulations.gov in docket 

number EPA-HQ-OPP-2014-0161.
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TIMELINE

EPA has created the following estimated timeline for the completion of the sethoxydim

registration review in Table 3 below. The projected timeline has not changed since the PWP. 

Table 3: Registration Review for Sethoxydim – Projected Registration Review Timeline

Activities Estimated Date

Opening the Docket

Open Docket and 60-day Public Comment Period March 2015 – Completed

Close Public Comment May 2015 – Completed

Case Development

Final Work Plan September 2015 – Completed

Issue DCI 2015 Oct. – Dec.

Data Submission 2017 Oct. – Dec.

60-day Public Comment Period for Draft Risk Assessments3 2019 April - June

Registration Review Decision

60-day Public Comment Period for Proposed Registration 

Review Decision

2020 January - March

Registration Review Decision and Begin Post-Decision Followup

2021

Total (years) 6

NEXT STEPS

As noted previously, the EPA plans to require several environmental fate, and ecological effects, 

studies for sethoxydim through a Data Call-In Notice, expected to be issued in 2015. 

 3 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, the 

agency plans to provide a 60 calendar day public comment period generally for draft risk assessments.