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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 bromacil. This work plan addresses public comments received 

concerning the Preliminary Work Plan (PWP), which was posted in bromacil’s registration 

review docket (EPA-HQ-OPP-2012-0445). Bromacil is a broad-spectrum herbicide registered 

for use to control weeds in the agricultural food crops citrus and pineapple. The lithium salt is 

not registered for agricultural uses; though both bromacil and its lithium salt are registered for 

use to control weeds and brush in several nonagricultural 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 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 website1

.

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 bromacil’s

registration review planned data needs, risk assessments expected to be conducted, and the 

projected registration review timeline. Lastly, there is a discussion of next steps.

UPDATES SINCE THE PWP WAS ISSUED

There have been no updates since the PWP was issued.

SUMMARY OF COMMENTS AND AGENCY RESPONSES

EPA published the Bromacil Preliminary Work Plan for a 60-day public comment on July 6, 

2012. The Federal Register Notice announcing the docket opening2 erroneously listed the 

comment period end date as August 19, 2012. However, on July 10, 2012, EPA extended the 

comment period until September 10, 2012 to allow for a full 60-day public comment period. The 

Agency received three public comments from DuPont Crop Protection. 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 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 does not capture every comment made on the PWP nor all of the Agency’s 

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

 1 http://www.epa.gov/oppsrrd1/registration_review/

2 See 77 FR 40048; FRL-9352-1.
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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, EPAHQ-OPP-2012-0445. Summarized public comments and Agency responses related to the 

anticipated ecological risk assessment or data needs are in the Response to Comments Submitted 

to the Bromacil Registration Review Docket (Docket ID: EPA-HQ-OPP-2012-0445; Case 

#0041) while those relevant to the anticipated human health risk assessment or data needs are in 

the Bromacil: Response to Comments on the Human-Health Assessment Scoping Document and 

Preliminary Workplan. 

Comments submitted by DuPont Crop Protection (DuPont) in EPA-HQ-OPP-2012-0445-

0010.

1. Comment: The Agency received a comment from DuPont regarding the toxicology database. 

DuPont states that bromacil had been re-evaluated for potential neurotoxicity to rodents and 

non-rodents in acute, subchronic, and chronic studies. DuPont believes that based on the 

available data for bromacil as well as a structure-activity relationship comparison, it can be 

concluded that bromacil is not a neurotoxin and the neurotoxicity screening battery can be 

waived.

EPA Response: Based on a weight-of-evidence approach of all available hazard and 

exposure information for bromacil, the Agency’s Hazard and Science Policy Council 

(HASPOC) concluded on November 8th, 2012 that acute and subchronic neurotoxicity 

studies are not required for bromacil at this time.

Comments submitted by DuPont Crop Protection in EPA-HQ-OPP-2012-0445-0011.

2. Comment: DuPont agrees to perform an acute avian toxicity study with bobwhite quail at the 

maximum label rate for use in the risk assessment if requested in a Data Call-In Notice.

EPA Response: The Agency thanks DuPont for their comment and will review the acute 

avian toxicity study upon receipt.

3. Comment: DuPont disagrees that tests need to be repeated for the seedling emergence and 

vegetative vigor studies, even though the original studies submitted utilized technical grade 

product instead of the required typical end-use product (TEP).

EPA Response: The Agency believes TEP is still needed for said studies as the formulated 

product contains detergents (surfactants) that are designed to enhance the toxicity of the 

active ingredient through facilitated uptake and/or transport. In addition, this request is 

supported by 37 reported incidents involving bromacil and terrestrial plants. As bromacil is 

an herbicide, an accurate measure of toxicity under field conditions is required in order to 

design effective mitigation for non-target terrestrial plants.
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Comments submitted by DuPont Crop Protection in EPA-HQ-OPP-2012-0445-0012.

4. Comment: DuPont references an open literature study (Sarmah et al., 2009) that they believe 

might fulfill GDLN 835.4100 – Aerobic Soil Metabolism.

EPA Response: The Agency thanks DuPont for their comment and recommends DuPont 

formally submit the referenced study if Agency review is desired. The Agency will evaluate 

the study upon receipt and determine its suitability for use in the risk assessment. If found 

acceptable this study would fulfill the requirement for GDLN 835.4100, and DuPont should 

respond to the DCI with the option to cite an existing study. If however, the study is 

determined to provide no additional useful information, the Agency will apply the 

conservative approach discussed in the problem formulation of multiplying the single 

available degradation half-life (MRID 40951510) by three to account for potential variability 

in degradation rates among different soil types. 

5. Comment: DuPont agrees with the Agency that additional data may not significantly alter 

the conservative nature of the assumed sorption coefficient for bromacil. DuPont cites that

reported open literature shows nearly identical values to the database cited in EFED’s 

Problem Formulation.

EPA Response: DuPont should formally submit the referenced open literature studies to the 

Agency if they would like these data to be considered at the time of the risk assessment. The 

Adsorption/Desorption, Batch Equilibrium Study (Guideline 835.1230) noted in the PWP as 

an anticipated data need will no longer be included in the registration review data call-in. 

6. Comment: DuPont agrees to consider providing an aerobic aquatic metabolism study 

[Guideline 835.4300] if such a requirement is included in the Data Call-In.

EPA Response: The Agency will review an aerobic aquatic metabolism study upon receipt. 

If this study is unacceptable or if DuPont does not submit a study, the Agency would make 

the conservative assumption that bromacil is stable to microbial degradation in the risk 

assessment.

7. Comment: DuPont suggests that an open-literature laboratory study (Wolf and Martin, 1974 

publication) may fulfill the anaerobic aquatic metabolism data requirement [Guideline 

835.4400]. If said study was found unacceptable, DuPont would consider providing an 

anaerobic aquatic metabolism study as required by the Data Call-In.

EPA Response: The referenced open-literature laboratory study was investigated during the 

problem formulation phase by the Agency. Although EPA has not completed a formal review 

of this study, an official review will be conducted prior to the initiation of the registration 

review risk assessment. DuPont should respond to the DCI with the option to cite an existing 

study. If this study is determined to be inadequate, the Agency would make the conservative 

assumption that bromacil is stable to microbial degradation in the risk assessment.
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PLANNED DATA NEEDS

The table below summarizes the planned data needs for bromacil based on the Registration 

Review: Preliminary Problem Formulation for Environmental Fate and Ecological Risk, Endangered 

Species, and Drinking Water Assessments for Bromacil and Bromacil Lithium salt (Case No. 0041),

Bromacil; Human-Health Assessment Scoping Document in Support of Registration Review,

Bromacil: Response to Comments on the Human-Health Assessment Scoping Document and 

Preliminary Workplan and Response to Comments Submitted to the Bromacil Registration 

Review Docket (Docket ID: EPA-HQ-OPP-2012-0445. The table has been updated since the 

PWP to reflect public comments that resulted in changes to the data needs.

Planned Data Needs for Bromacil’s Registration Review

Guideline 

Number Study Title Test Material

Estimated 

Timeframe

(Months from 

receipt of DCI)

835.4100 Aerobic Soil Metabolism TGAI 24

835.4300 Aerobic Aquatic Metabolism TGAI 24

835.4400 Anaerobic Aquatic Metabolism TGAI 24

850.2100 Avian acute oral toxicity3 TGAI 12

850.4100 Seedling Emergence and Seedling Growth4 TEP 12

850.4150 Vegetative Vigor4 TEP 12

870.3465 90-day inhalation toxicity TGAI 24

870.7800 Immunotoxicity TGAI 12

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

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Data are needed for the upland game species Bobwhite Quail. 4 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 Agency will conduct a comprehensive ecological risk assessment, 

including an endangered species assessment, for all uses of bromacil. For human health, EPA 

will conduct revised dietary 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.

The table below summarizes the planned registration review risk assessments based on the EFED 

Problem Formulation and HED Scoping Document. The planned assessments have not changed 

from what was included in the PWP.

Planned Risk Assessments for Bromacil’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 bromacil’s reported ecological 

incidents, see page 66 of the Problem Formulation.

Human Health

Dietary

Food Y Registered for the food crops citrus and pineapple.

Drinking water Y The assessment will include available surface and 

groundwater monitoring data, taking into 

consideration any changes in use patterns that have 

occurred.

Occupational

Handlers (mixers, loaders, 

applicators)

Y

Post-application Y Required for citrus and pineapple.

Residential

Handlers N There are currently no registered uses of bromacil 

and its lithium salts that would result in residential 

exposure. Therefore, a residential exposure 

assessment is not needed to support Registration 

Review.

Post-application N

Other
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Aggregate Y Evaluates the combined risk from dietary and 

residential exposures. As there are no registered uses 

that would result in residential exposure, the 

aggregate risk assessment will be equivalent to the 

dietary assessment.

Cumulative N Available data do not suggest that bromacil has a 

common mode/mechanism of toxicity with any other 

chemical.

Tolerances Y The tolerance expression for bromacil will be 

reviewed during registration review to ensure that it 

appropriately covers the metabolites and degradates 

of bromacil and that it specifies the residues to be 

measured for each commodity.

Incidents Y For a discussion of bromacil’s reported human 

incidents, see page 14 of the Scoping Document.

TIMELINE

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

review. The projected timeline has not changed since the PWP.

Registration Review for Bromacil – Projected Registration Review Timeline

Activities Estimated Date

Opening the Docket

Open Docket and 60-day Public Comment Period June 2012 – Completed

Close Public Comment August 2012 – Completed

Case Development

Final Work Plan December 2012 – Completed

Issue DCI 2013 – July – Sept.

Data Submission 2015 – July – Sept.

30-day Public Comment Period for Draft Risk Assessments 2017 – Jan. – March

Registration Review Decision

60-day Public Comment Period for Proposed Registration Review 

Decision

2017 – July – Sept.

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 bromacil through a data call-in, expected to be issued in 2013.