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Rimsulfuron Preliminary Work Plan – Table of Contents

Overview 3

Anticipated Data Needs 4

Statutory and Regulatory Authority 5

Chemical Facts 5

Use and Usage Information 6

Recent Actions 7

Anticipated Risk Assessments for Registration Review 7

Timeline 8

Next Steps 9

Appendix – Additional Areas Considered in Rimsulfuron’s Registration Review 10

References:

This Preliminary Work Plan summarizes the Environmental Protection Agency's current position 

based on the following documents:

1. Registration Review: Preliminary Problem Formulation for Environmental Fate, 

Ecological Risk, Endangered Species, and Human Health Drinking Water Exposure 

Assessments for Rimsulfuron. September 13, 2012

2. Rimsulfuron. Human Health Assessment Scoping Document in Support of Registration 

Review. May 21, 2012

3. Biological and Economic Analysis Division Chemical Profile for Registration Review: 

Rimsulfuron. April 5, 2012

4. Rimsulfuron: Review of Human Incidents. May 8, 2012

These and other supporting documents for the rimsulfuron registration review case may be found 

in the docket EPA-HQ-OPP-2012-0178 at http://www.regulations.gov.
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OVERVIEW

The docket for rimsulfuron is now open, initiating the first public comment period for this 

registration review (docket number EPA-HQ-OPP-2012-0178). Rimsulfuron is a selective 

herbicide registered for use to control broadleaf and grassy weeds on various agricultural and 

non-agricultural food and non-food sites. There are no registered residential uses. This 

Preliminary Work Plan (PWP) document explains what EPA's Office of Pesticide Programs

knows about rimsulfuron, highlighting anticipated data and assessment needs, identifying the 

types of information that would be especially useful to the Agency in conducting the review, and

providing an anticipated timeline for completing rimsulfuron’s review.

The registration review process was designed to include a public participation component to 

solicit input from interested stakeholders. The Agency intends, by sharing this information in the 

docket, to inform the public of what it knows about rimsulfuron and what types of new data or 

other information would be helpful for the Agency to receive as it moves toward a decision on 

rimsulfuron. The Agency encourages all interested stakeholders to review the PWP and 

Appendix and to provide comments and additional information that will help the Agency’s 

decision-making process for this chemical. In addition to general areas on which persons may 

wish to comment, there are some areas identified in the PWP and Appendix about which the 

Agency specifically seeks comments and information. Interested stakeholders could include: 

environmental non-profit or interest groups; pesticide manufacturers; agricultural labor or 

commodity groups; commercial, institutional, residential, and other users of pesticides; or the 

public at large.

The Preliminary Work Plan begins by listing the anticipated data needs for rimsulfuron. Next, it 

discusses the statutory and regulatory authority for Registration Review. Then the document 

provides rimsulfuron chemical facts, use and usage information, recent actions, the anticipated 

risk assessments, and a projected registration review timeline. Finally, the Appendix to this 

document includes identification and discussion of some areas that are considered generally in 

Registration Review along with some additional chemical case-specific information.
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ANTICIPATED DATA NEEDS

The table below summarizes anticipated data needs for rimsulfuron. There are no anticipated 

human health data needs. For additional discussion of the anticipated data needs, see the 

September 13, 2012 Registration Review: Preliminary Problem Formulation for Environmental 

Fate, Ecological Risk, Endangered Species, and Human Health Drinking Water Exposure 

Assessments for Rimsulfuron and the May 21, 2012 Rimsulfuron. Human Health Assessment 

Scoping Document in Support of Registration Review.

Anticipated Data Needs for the Registration Review of Rimsulfuron

Guideline 

Number Study Title Test Material

Estimated 

Timeframe

(Months from 

receipt of 

DCI)

835.4400 Anaerobic aquatic metabolism1 Degradates 24

835.6100 Terrestrial field dissipation study2 TGAI and 

degradates 12

835.6200 Aquatic field dissipation study2 TGAI and 

degradates 12

850.1350 Aquatic invertebrate life-cycle (marine)3 TGAI 12

850.1400 Estuarine/marine fish early life stage3 TGAI 12

850.4100 Terrestrial plant toxicity, seedling emergence, 

Tier II TEP 12

850.4150 Terrestrial plant toxicity, vegetative vigor, Tier 

II TEP 12

The studies listed below were previously required and are under review. They will NOT be 

included in the anticipated Registration Review DCI. However, if the studies are not 

determined to be acceptable, the registrants will have to resubmit or upgrade them.

835.4100 Aerobic Soil Metabolism TGAI and 

degradates In review

835.4300 Aerobic aquatic metabolism TGAI and 

degradates In review

850.1300 Aquatic invertebrate life-cycle (freshwater) TGAI In review

850.1400 Freshwater fish early life-stage TGAI In review

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

 1 A study has been submitted that is scientifically valid but additional characterization of secondary metabolites is 

anticipated to be required. 2 See footnote 7 of 40 CFR 158.1300. EPA anticipates requiring only the environmental chemistry analytical 

methods and independent laboratory (ILV) portions of this guideline for soil and water, rather than the full field 

dissipation study. 3 Results from the review of the submitted freshwater studies may negate the need for additional data.
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STATUTORY AND REGULATORY AUTHORITY

The Food Quality Protection Act (FQPA) of 1996 mandated a registration review program. All 

pesticides distributed or sold in the United States (U.S.) generally must be registered by the 

Environmental Protection Agency (EPA or the Agency), based on scientific data showing that 

they will not cause unreasonable risks to human health or the environment when used as directed 

on product labeling. 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 of no unreasonable adverse effects to human health or the 

environment. Changes in science, public policy, and pesticide use practices will occur over time. 

Through the registration review program, the Agency periodically reevaluates pesticides to make 

sure that as change occurs, products in the marketplace can be used safely. Information on this 

program is provided on EPA’s website4.

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. The regulations governing registration review begin at 40 CFR 155.40. The 

Agency will consider benefits information and data as required by FIFRA. The public phase of 

registration review begins when the initial docket is opened for each case. The docket is the 

Agency’s opportunity to state what it knows about the pesticide and what additional risk analyses 

and data or information it believes are needed to make a registration review decision. After 

reviewing and responding to comments and data received in the docket during this initial 

comment period, the Agency will develop a Final Work Plan (FWP) and anticipated schedule for 

the registration review of rimsulfuron.

RIMSULFURON CHEMICAL FACTS

PC code 129009

Case Number 7218

CAS Number 122931-48-0

Year first registered 1994

Pesticide Type Herbicide

Chemical class Sulfonylurea

Reregistration Eligibility 

Decision (RED)

Because it was registered after November 1984, rimsulfuron was 

not subject to reregistration.

Tolerance Reassessment 

Eligibility Decision 

(TRED)

Not applicable

Cumulative group Not applicable

40 CFR Citation Tolerances for rimsulfuron are established in 40 CFR 180.478

Dual-use Conventional pesticidal uses only

Non-pesticidal uses None specifically for rimsulfuron, but sulfonlyureas are FDA 

approved for treatment of diabetes.

 4 http://www.epa.gov/oppsrrd1/registration_review/
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Pesticide Re-evaluation 

Division, Chemical 

Review Manager

Jose Gayoso

gayoso.jose@epa.gov

(703) 347-8652

Registration Division, 

Product Manager

Kable Bo Davis

davis.kable@epa.gov

(703) 306-0415

USE AND USAGE INFORMATION

Please see the BEAD Chemical Profile for Registration Review: Rimsulfuron in the registration 

review docket for more details.

Summary of Use Selective herbicide registered for use to control pre-plant, preemergence, and post-emergence broadleaf and grassy weeds.

Use Sites Various crops, primarily corn, as well as various non-crop uses, 

including non-residential lawns and turfs, and uncultivated areas.

Summary of Usage In 1998-2010, an average of 92,000 lbs. was applied per year to 

agricultural crops. The top agricultural crops were corn, potatoes, 

tomatoes, and almonds. Until recent years, agricultural usage was in 

decline since 2004.

National level usage data for non-agricultural uses are not available.

Formulation Type(s) Water dispersible granules (dry flowable), emulsifiable 

concentrates, soluble concentrates/solids.

Application Method(s) Aerial and ground (broadcast, band, chemigation)

Technical Registrant(s) DuPont, Cheminova, Quena Plant Protection

No. of Registrations 36 Section 3 registrations5

Restricted Use There are two restricted use products with the active ingredient 

rimsulfuron. Registrations 352-585 and 352-619 are coformulated 

with atrazine and are Restricted Use Pesticides due to ground and 

surface water concerns.

Guidance for Commenters: Additional areas of use and usage related information

requested for this registration review, and of particular interest to EPA, are described below.

• Usage/use information for non-agricultural uses

• Confirmation of the following label information: sites of application; formulations;

application methods and equipment; maximum application rates; frequency of 

application, application intervals, and maximum number of applications per season; 

geographic limitations on use.

• Use distribution (e.g., acreage and geographical distribution of relevant use sites)

• Median and 90th percentile reported use rates (lbs ai/1000 sq ft) from usage data –

national, state, and county

• Application timing (date of first application and application intervals) – national, state, 

and county

 5 Section 3 product labels can be obtained from the Pesticide Product Label System (PPLS) website 

(http://oaspub.epa.gov/pestlabl/ppls.home).
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• Typical application interval (days)

• State or local use restrictions

• Foreign technical registrants not listed above who supply technical rimsulfuron to the US 

market

RECENT ACTIONS

A tolerance on chicory was established on August 3, 2012 (FRL-9355-5).

ANTICIPATED RISK ASSESSMENTS FOR REGISTRATION REVIEW

The most recent comprehensive human health risk assessment for rimsulfuron was completed on 

May 4, 2012 for a registration related new use request for use on chicory. The most recent 

ecological and environmental fate risk assessment was completed March 20, 2012 for the same 

purpose. Findings and conclusions from these risk assessments are summarized in the

September 13, 2012 Registration Review: Preliminary Problem Formulation for Environmental 

Fate, Ecological Risk, Endangered Species, and Human Health Drinking Water Exposure 

Assessments for Rimsulfuron and the May 21, 2012 Rimsulfuron. Human Health Assessment 

Scoping Document in Support of Registration Review.

During registration review, the Agency anticipates the need to conduct a comprehensive

ecological risk assessment, including an endangered species assessment, for all uses of

rimsulfuron. For human health, EPA anticipates the need to conduct revised residential and 

occupational risk assessments during registration review. If toxicological endpoints or points of 

departure are revised based on the data that are anticipated to be 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.

The table below summarizes the anticipated registration review risk assessments based on the 

EFED Problem Formulation and HED Scoping Document.

Anticipated Risk Assessments for Rimsulfuron’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 

Y

Incidents Y For a discussion of rimsulfuron’s reported ecological 

incidents, see page 22 of the Problem Formulation.

Human Health

Dietary

Food N

Drinking water N
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Occupational

Handlers (mixers, loaders, 

applicators)

Y Occupational handler exposure and risk assessments 

are anticipated for the following uses: golf course, sod 

farms athletic fields, industrial and commercial lawns 

and similar nonresidential areas; agricultural food 

crops including soybeans, potatoes, field corn, 

tomatoes, grapes, various tree fruits, and tree nuts.

Post-application Y Occupational post-application exposure and risk 

assessments are anticipated for the following uses: 

soybeans, potatoes, field corn, tomatoes, grapes, 

various tree fruits, tree nuts, and golf course turf.

Residential

Handlers N

Post-application Y Based on the current use patterns, there is only 

potential for post-application dermal exposure for 

recreational golfers. Therefore, a new risk assessment 

is anticipated for the existing golf course turf use. 

Other

Aggregate Y A new aggregate assessment may be needed to 

include the short-term dermal exposure for the

recreational golfer.

Cumulative N

Tolerances N

Incidents Y For a discussion of rimsulfuron’s reported human 

incidents, see page 7 of the Scoping Document.

TIMELINE

EPA has created the following estimated timeline for the completion of rimsulfuron’s 

registration review.

Registration Review for Rimsulfuron– Projected Registration Review Timeline

Activities Estimated Date

Opening the Docket

Open Docket and 60-day Public Comment Period 2012 – September

Close Public Comment 2012 – November 

Case Development

Final Work Plan 2013 – February 

Issue DCI 2013 – Oct.-Dec.

Data Submission 2015 – Oct.-Dec. 

Open 30-day Public Comment Period for Draft Risk Assessments 2017 – April - June 

Close Public Comment Period 2017 – July - Sept.

Registration Review Decision
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Registration Review for Rimsulfuron– Projected Registration Review Timeline

Activities Estimated Date

Open 60-day Public Comment Period for Proposed Registration Review 

Decision

2017 – Oct.-Dec.

Close Public Comment Period 2018 – Jan.-March 

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

Total (years) 6

NEXT STEPS

After the 60-day public comment period closes, the Agency will review and respond to any 

comments received in a timely manner and then issue a Final Work Plan for the registration 

review of rimsulfuron.
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Appendix – Additional Areas Considered in Rimsulfuron’s Registration 

Review

PUBLIC COMMENTS AND FEEDBACK:

Guidance for Commenters: The areas below highlight topics of special interest to the Agency 

where your comments, data submissions, or reference to sources of additional information could 

be of particular use.

Trade Irritants:

Through the registration review process, the Agency intends to solicit information on trade 

irritants and, to the extent feasible, take steps toward facilitating irritant resolution. The Agency 

will work to harmonize tolerances and international maximum residue limits (MRLs) and may 

modify tolerance levels to do so, when possible. Growers and other stakeholders are asked to 

comment on any trade irritant issues resulting from lack of MRLs or disparities between U.S. 

tolerances and MRLs in key export markets, providing as much specificity as possible regarding 

the nature of the concern. 

Water Quality:

Rimsulfuron is not identified as a cause of impairment for any water bodies listed as impaired 

under section 303(d) of the Clean Water Act6

. In addition, no Total Maximum Daily Loads 

(TMDL) have been developed for rimsulfuron7

. More information on impaired water bodies and 

TMDLs can be found at the Agency’s website8

. The Agency invites submission of water 

quality data for this pesticide. To the extent possible, data should conform to the quality 

standards in Appendix A of the OPP Standard Operating Procedure: Inclusion of Impaired 

Water Body and Other Water Quality Data in OPP’s Registration Review Risk Assessment and 

Management Process9 in order to ensure they can be used quantitatively or qualitatively in 

pesticide risk assessments.

Environmental Justice:

EPA seeks to achieve environmental justice, the fair treatment and meaningful involvement of all 

people, regardless of race, color, national origin, or income, in the development, implementation, 

and enforcement of environmental laws, regulations, and policies. To help address potential 

environmental justice issues, the Agency seeks information on any groups or segments of the 

population who, as a result of their location, cultural practices, or other factors, may have 

atypical, unusually high exposure to rimsulfuron compared to the general population. Please 

comment if you are aware of any sub-populations that may have atypical, unusually high 

exposure compared to the general population.

 6 http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=885

7

http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id=885&p_pollutant_

group_name=PESTICIDES

8 http://www.epa.gov/owow/tmdl/

9 http://www.epa.gov/oppsrrd1/registration_review/water_quality_sop.htm
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ENDANGERED SPECIES:

A risk assessment that supports a complete endangered species determination has not been 

conducted for rimsulfuron. The ecological risk assessment planned during registration review 

will allow the Agency to determine whether rimsulfuron’s use has “no effect” or “may affect” 

federally listed threatened or endangered species (listed species) or their designated critical

habitats. When an assessment concludes that a pesticide’s use “may affect” a listed species or its 

designated critical habitat, the Agency will consult with the U.S. Fish and Wildlife Service 

and/or National Marine Fisheries Service (the Services), as appropriate.

ENDOCRINE DISRUPTOR SCREENING PROGRAM:

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse 

outcomes from exposure to chemicals. Collectively, these studies include acute, subchronic and 

chronic toxicity, including assessments of carcinogenicity, neurotoxicity, developmental, 

reproductive, and general or systemic toxicity. These studies include endpoints which may be 

susceptible to endocrine influence, including effects on endocrine target organ histopathology, 

organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, reproductive loss, 

and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and 

chronic studies that assess growth, developmental and reproductive effects in different 

taxonomic groups. As part of its most recent registration decision for rimsulfuron EPA,

reviewed these data and selected the most sensitive endpoints for relevant risk assessment 

scenarios from the existing hazard database. However, as required by FFDCA section 408(p), 

rimsulfuron is subject to the endocrine screening part of the Endocrine Disruptor Screening 

Program (EDSP). 

EPA has developed the EDSP to determine whether certain substances (including pesticide 

active and other ingredients) may have an effect in humans or wildlife similar to an effect 

produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator 

may designate.” The EDSP employs a two-tiered approach to making the statutorily required 

determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a 

chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal 

systems. Chemicals that go through Tier 1 screening and are found to have the potential to 

interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA 

will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 

testing is designed to identify any adverse endocrine-related effects caused by the substance, and 

establish a dose-response relationship between the dose and the E, A, or T effect. 

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between 

October 2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 

chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. Rimsulfuron is 

not among the group of 58 pesticide active ingredients on the initial list to be screened under the 

EDSP. Accordingly, as part of registration review, EPA will issue future EDSP orders/data callins, requiring the submission of EDSP screening assays for rimsulfuron.
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For further information on the status of the EDSP, the policies and procedures, the list of 67 

chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our 

website10.

HUMAN STUDIES:

Occupational

Past rimsulfuron risk assessments rely in part on data from studies in which adult human subjects 

were intentionally exposed to a pesticide to determine their dermal and inhalation exposure. 

Many such studies, involving exposure to many different pesticides, comprise generic pesticide 

exposure databases such as the Pesticide Handlers Exposure Database (PHED) and the 

Agricultural Reentry Task Force (ARTF) Database. EPA has reviewed all the studies supporting 

these multi-pesticide generic exposure databases, and has found no clear and convincing 

evidence that the conduct of any of them was either fundamentally unethical or significantly 

deficient relative to the ethical standards prevailing at the time the research was conducted. All 

applicable requirements of EPA’s Rule for the Protection of Human Subjects of Research (40 

CFR Part 26) have been satisfied, and there is no regulatory barrier to continued reliance on 

these studies.

 10 http://www.epa.gov/endo/