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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 sulfometuron methyl. This work plan addresses public comments 

received concerning the Preliminary Work Plan (PWP), which was posted in the sulfometuron 

methyl registration review docket (EPA-HQ-OPP-2012-0433). Sulfometuron methyl is a 

sulfonylurea herbicide. It is a non-food/non-feed use chemical currently registered for 

commercial pre- and post-emergent applications to manage annual and perennial broadleaf 

weeds and grasses in non-agricultural sites (i.e., forestry, rights of way, non-crop industrial sites, 

and unimproved turf).

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 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 sulfometuron methyl. Lastly, there is a discussion of next steps.

UPDATES SINCE THE PWP WAS ISSUED

There are no additional updates on sulfometuron methyl since the PWP.

SUMMARY OF COMMENTS AND AGENCY RESPONSES

During the 60-day public comment period on the Sulfometuron Methyl Preliminary Work Plan, 

which opened on December 14, 2012 and closed on February 12, 2013, the Agency received five

public comments. Comments were submitted by the technical registrant DuPont and the FIFRA 

Endangered Species Taskforce (FESTF). The comments address the planned ecological and 

human health risk assessments, data requirements, use and usage information, and water quality 

concerns. In the PWP, EPA also solicited comments on the specific topics of environmental 

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

This section does not capture every comment made about the PWP nor all of the Agency’s 

responses. Summarized below are public comments that resulted in changes to the anticipated

registration review data needs, risk assessments, or timeline, or are of a broader regulatory 

nature. Public comments and EPA responses in their entirety are located in the docket, EPA-

 1 http://www.epa.gov/oppsrrd1/registration_review/
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HQ-OPP-2012-0433. Summarized public comments and Agency responses related to the 

anticipated ecological risk assessment are in the Response to DuPont Crop Protection Comments 

regarding EFED Problem Formulation on the Registration Review of Sulfometuron (D409662)

while those relevant to the anticipated human health risk assessment are in the Sulfometuron 

Methyl: Response to Comments for the Human Health Scoping Document in Support of 

Registration Review (D409661). 

Comments submitted by FIFRA Endangered Species Task Force (FESTF) in EPA-HQOPP-2012-0433-0016.

1. Comment: FESTF submitted a comment that sulfometuron methyl technical registrants 

DuPont and Nufarm Limited are members of the FESTF task force and are entitled to rely on 

data submitted by FESTF.

Response: The Agency thanks FESTF for its comment and will consider this information 

as it conducts the registration review process and makes its registration review decision.

Comments submitted by the technical registrant DuPont in EPA-HQ-OPP-2012-0433-0015.

3. Comment: DuPont informed the Agency of international uses and proposed uses of 

sulfometuron methyl.

Response: The Agency appreciates this information and will consider this information as 

it conducts the registration review process and makes its registration review decision.

4. Comment: DuPont offered some corrections to use estimates for lawn care operators cited in 

the BEAD Chemical Profile for Registration Review.

Response: The Agency appreciates this information and will consider this information as 

it conducts the registration review process and makes its registration review decision.

5. Comment: DuPont wants to ensure that sulfometuron methyl’s rangeland restoration use is 

included in future risk assessments conducted to support registration review.

Response: The Agency will conduct a comprehensive ecological risk assessment, 

including an endangered species assessment, for all uses of sulfometuron methyl. For 

human health, if exposure or toxicological estimates change, EPA may revise dietary, 

residential, and occupational risk assessments during registration review.

6. Comment: DuPont noted that the PWP incorrectly states that sulfometuron methyl is not 

labeled for agricultural uses. DuPont points out that sulfometuron methyl containing products 

are registered for use in forestry, conifer and hardwood cultivation, and rangeland restoration. 

All of these uses are considered agricultural crops and regulated under the Worker Protection 

Standard for Agricultural Workers.

Response: The Agency appreciates this clarification and will correct this use distinction 

in future documents. 
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7. Comment: DuPont commented that it is unaware of any ecological incident or water quality 

monitoring data for sulfometuron methyl which has not already been reported to the Agency in 

accordance with FIFRA 6(a)(2). DuPont also intends to continue reporting all incidents in

compliance with FIFRA reporting requirements. Specifically regarding water quality 

monitoring data, DuPont has become aware of water quality monitoring data and DuPont has

reported this data to EPA in accordance with FIFRA 6(a)(2). Since there is no established 

maximum contaminant levels (MCLs) for sulfometuron methyl all detections have been reported 

as Category "G-C" in accordance with regulations. Since 1998 there have been seven reported 

detections. These reports reflect second-hand information received from state regulatory 

agencies and other individuals. DuPont does not have any self-generated water quality 

monitoring data.

Response: EPA appreciates DuPont sharing this information. 

Comments submitted by the technical registrant DuPont in EPA-HQ-OPP-2012-0433-0014.

8. Comment: DuPont commented on EPA’s classification of sulfometuron methyl as toxicity 

category III based on a 1980 eye irritation study in rabbits (MRID 00071412). This 1980 study 

was conducted with a 75% formulation and has recently been repeated with a 99.1% technical 

grade sulfometuron methyl (MRID 41672807). The more recently conducted study (MRID 

41672807) demonstrates sulfometuron methyl is less of an ocular irritant than previously 

demonstrated by the 1980 study (MRID 00071412). DuPont requests that the Agency review the 

newer eye irritation study and reconsider sulfometuron methyl’s toxicity classification.

Response: EPA will review the above referenced study (MRID 41672807) and consider 

it for use in classification of eye irritation for sulfometuron methyl. 

PLANNED DATA NEEDS

Table 1 below summarizes the planned data needs for sulfometuron methyl based on the 

Registration Review: Preliminary Problem Formulation for Environmental Fate, Ecological 

Risk, Endangered Species, and Human Health Drinking Water Exposure Assessments for 

Sulfometuron Methyl and Sulfometuron Methyl: Human Health Assessment Scoping Document 

in Support of Registration Review. The planned data needs have not changed from what was 

included in the PWP.
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Table 1. Planned Data Needs for Sulfometuron Methyl’s Registration Review

Guideline 

Number Study Title Test Material

Estimated 

Timeframe

(Months from 

receipt of DCI)

850.6100

Environmental Chemistry Methods and Associated 

Independent Laboratory Validation for Soil and 

Water2

TGAI & 

Degradates3 12

835.4100 Aerobic Soil Metabolism TGAI & TEP 24

870.7800 Immunotoxicity Study TGAI 12

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

RISK ASSESSMENTS FOR REGISTRATION REVIEW

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

including an endangered species assessment, for all uses of sulfometuron methyl. For human 

health, EPA will conduct revised dietary, residential, and occupational 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 assumptions.

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

Problem Formulation and HED Scoping Document and the planned assessments have not 

changed from what was included in the PWP.

Table 2. Planned Risk Assessments for Sulfometuron Methyl’s 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 

Yes Risk assessment will be conducted on parent 

sulfometuron methyl. 

 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-2009-0154-0008 3 Environmental chemistry methods should be submitted with their associated independent laboratory validations for 

parent sulfometuron methyl and its major degradates sulfometuron pyrimidine amine (IN-X0993), sulfometuron 

sulfonamide (IN-D5803), and saccharin (IN-581) in water and soil.
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Incidents Yes The planned assessment will consider ecological 

incidents attributed to sulfometuron methyl use. For a 

discussion of sulfometuron methyl’s reported 

ecological incidents, see page 28 of the Problem 

Formulation.

Human Health

Dietary

Food No No food uses

Drinking water No May be updated and will reflect any revisions or 

updates to the toxicological endpoints.

Occupational

Handlers (mixers, loaders, 

applicators)

No Based upon current use patterns, a new occupational 

handler assessment is not needed at this time. If 

occupational exposure estimates or toxicological 

endpoints change, the occupational handler 

assessment will be updated.

Post-application No Based upon current use patterns, a new occupational 

post-application assessment is not needed at this time. 

If post-application occupational exposure estimates or 

toxicological endpoints change, the occupational 

handler assessment will be updated.

Residential

Handlers No Not registered for residential use.

Post-application No Not registered for residential use.

Other

Aggregate No Evaluates the combined risk from dietary and 

residential exposures. There are no registered 

residential uses. 

Cumulative No Sulfometuron methyl has not been identified as a 

member of a common mechanism group for 

cumulative risk assessment.

Tolerances No There are no registered food uses, and therefore no 

tolerances. 
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Incidents The planned assessment will consider human 

incidents attributed to sulfometuron methyl use. For a 

discussion of sulfometuron methyl’s reported human 

incidents, see Sulfometuron Methyl: Review of Human 

Incidents in docket EPA-HQ-OPP-2012-0433 at 

http://www.regulations.gov

TIMELINE

EPA has created the following estimated timeline for the completion of the sulfometuron methyl

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

Table 3: Registration Review for Sulfometuron Methyl – Projected Registration Review 

Timeline

Activities Estimated Date

Opening the Docket

Open Docket and 60-day Public Comment Period 2012 – Dec.

Close Public Comment 2013 – Feb.

Case Development

Final Work Plan 2013 - May

Issue DCI 2014 - Jan. - Mar.

Data Submission 2016 - Jan. - Mar.

60-day Public Comment Period for Draft Risk Assessments4 2017 - Jul. - Sep.

Registration Review Decision

60-day Public Comment Period for Proposed Registration Review 

Decision

2018 - Jan. - Mar.

Registration Review Decision and Begin Post-Decision Follow-up 2018

Total (years) 6

NEXT STEPS

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

and human health studies for sulfometuron methyl through a Data Call-In Notice, expected to be 

issued in early 2014.

 4 The regulations governing Registration Review 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). The Agency plans to provide a 60 calendar

day public comment period for draft risk assessments as a general standard of practice.