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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 fluazifop-p-butyl. This work plan addresses public comments received 

concerning the Preliminary Work Plan (PWP), which was posted in the fluazifop-p-butyl

registration review docket (EPA-HQ-OPP-2014-0779). Fluazifop-p-butyl is a selective, postemergent herbicide registered for the control of perennial and annual grass weeds. Fluazifop-pbutyl's registered uses include food/feed use on asparagus, carrot, coffee, cotton, endive 

(escarole), garlic, macadamia nut, onion, pecan, pepper, rhubarb, soybeans, stone fruits, sweet 

potato, bananas, citrus, grapes, sugar beets, and yams. It is also registered for use on lawns/turf 

in residential settings.

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 fluazifop-p-butyl. Lastly, there is a discussion of next steps.

UPDATES SINCE THE PWP WAS ISSUED

Field trial of residues in pollen and nectar, semi-field testing for pollinators, and field testing for 

pollinators studies were added following the PWP due to implementation of pollinator risk 

assessment guidance.

There are no additional updates on fluazifop-p-butyl since the PWP.

SUMMARY OF COMMENTS AND AGENCY RESPONSES

During the 60-day public comment period on the Fluazifop-p-butyl Preliminary Work Plan, 

which opened on December 19, 2014 and closed on February 19, 2015, the Agency received 

three public comments. Comments were submitted by the FIFRA Endangered Species Task 

Force (FESTF), the Center for Biological Diversity (CBD), and Syngenta Crop Protection, LLC. 

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 

 1 http://www.epa.gov/oppsrrd1/registration_review/
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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 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 are of a broader regulatory nature. Public 

comments in their entirety are located in the docket, EPA-HQ-OPP-2014-0779. Summarized 

public comments and Agency responses related to the anticipated ecological data needs are in the 

EFED memo titled EFED Response to Registrant Comments Regarding the Registration Review 

Problem Formulation for Fluazifop-p-butyl. 

Comments submitted by the FIFRA Endangered Species Task Force (FESTF) in EPA-HQOPP-2014-0779-0007

Comment: FESTF submitted a comment informing the Agency that the technical registrant of fluazifop-p-butyl,

Syngenta Crop Protection, LLC, is a member of the FESTF (or a company having met its data compensation 

obligations) and is entitled to rely on FESTF data.

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

registration review.

Comments submitted by the Center for Biological Diversity (CBD) in EPA-HQ-OPP-2014-

0779-0006

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 

fluazifop-p-butyl 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 fluazifop-pbutyl on endangered and threatened (listed) species and their designated critical habitat for the fluazifop-p-butyl

registration review. 

 

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

for fluazifop-p-butyl 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 fluazifop-p-butyl in connection with the development of its final registration 

review decision for fluazifop-p-butyl.

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 between the EPA and 

the Services. The NAS report outlines recommendations on specific scientific and technical issues 
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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 workshop in April 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 fluazifop-p-butyl

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 fluazifop-p-butyl , EPA described the screening-level risk 

assessment to determine the potential effects of fluazifop-p-butyl 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 fluazifop-p-butyl . 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 fluazifop-p-butyl 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 fluazifop-p-butyl as part of completing this registration review.

Comments submitted by Syngenta Crop Protection in EPA-HQ-OPP-2014-0779-0012.

3. Comment: Syngenta notes that MRID 00162453 provided adult honeybee acute oral data, 

and proposes that MRID00162453 will satisfy the honey bee adult acute oral data 

requirement.

Response: EPA acknowledges this data has been submitted, and has been found adequate for 

a limit test. No new adult oral bee data are required.
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PLANNED DATA NEEDS

Table 1 below summarizes the planned data needs for fluazifop-p-butyl based on EFED 

Registration Review Problem Formulation for Fluazifop-p-butyl and Fluazifop-p-butyl: Human 

Health Risk Assessment Scoping Document in Support of Registration Review, and Response to 

Comments document. The table has been updated since the PWP to reflect public comments 

which resulted in changes to the data needs. Field trial of residues in pollen and nectar, semifield testing for pollinators, field testing for pollinators studies were added following the PWP 

due to implementation of pollinator risk assessment guidance.

Table 1: Anticipated Data Needs for the Fluazifop-p-butyl Registration Review

Guideline 

Number2 Study Title1

Test Material

Estimated 

Timeframe

(Months from 

receipt of DCI)

835.1230

835.1240 Adsorption/Desorption

TGAI and 

Degradate: 

fluazifop-p-acid

12

835.4400 Anaerobic aquatic metabolism TGAI 24

850.1350 Aquatic invertebrate life cycle (saltwater) Degradate: 

fluazifop-p acid 12

850.1400 Fish early-life stage toxicity (saltwater) Degradate: 

fluazifop-p acid 12

850.2300 Avian Reproduction Degradate: 

fluazifop-p acid 24

850.4100 Seedling emergence and seedling growth (Tier I) TEP 12

850.4150 Vegetative vigor (Tier I) TEP 12

850.4400 Aquatic plant growth (aquatic vascular plant 

toxicity) (Tier II)

Degradate: 

fluazifop-p acid 12

850.5400 Algal Toxicity (Tier II) Degradate: 

fluazifop-p acid 12

850.4550 Cyanobacteria Toxicity (Tier II) Degradate: 

fluazifop-p acid 12

NonGuideline*Honeybee adult chronic oral toxicity TGAI 12

NonGuideline*Honeybee larval acute toxicity TGAI 12

NonGuideline*Honeybee larval chronic toxicity TGAI 12

Nonguideline**Field trial of residues in pollen and nectar TGAI 24

 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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Table 1: Anticipated Data Needs for the Fluazifop-p-butyl Registration Review

Guideline 

Number2 Study Title1

Test Material

Estimated 

Timeframe

(Months from 

receipt of DCI)

Nonguideline**Semi-field testing for pollinators TGAI 24

850.3040** Field testing for pollinators TGAI 24

850.6100 Environmental chemistry methods and 

associated independent laboratory validation for 

water and soil

TGAI and 

Degradate: 

fluazifop-p-acid

12

860.1900 Field Accumulation in Rotational Crops TEP 24

870.3250 90-day Dermal toxicity TEP 24

870.3465 90-Day/28-Day Inhalation Toxicity TEP 24

875.2100 Turf Transferable Residue Data TEP 12

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

*Tier 1 (Laboratory-based studies)

**Tier 2 and 3 (Semi-field and full field colony-level studies) The need for a higher tier test for pollinators will be 

determined based upon lower-tiered tests and/or other lines of data and the need for a refined pollinator risk 

assessment.

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 fluazifop-p-butyl. 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.
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Table 2: Planned Risk Assessments for the Fluazifop-p-butyl 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 EPA anticipates conducting an updated 

comprehensive ecological risk assessment during 

registration review. The new assessment will 

incorporate the most up-to-date modeling 

methodologies, updated toxicological endpoints, and 

data submitted under the anticipated registration 

review Data Call-In Notice. 

Incidents Will check for 

updates

For a discussion of reported ecological incidents for 

fluazifop-p-butyl, see page 32 of the Problem 

Formulation.

Human Health

Dietary

Food No A new dietary assessment may be required if 1) there 

are any significant changes to toxicological Points of 

Departure (PODs) or uncertainty factors, or 2) EFED 

recommends higher estimated drinking water 

concentrations (EDWCs) than the current values. 

Drinking water

Occupational

Handlers (mixers, loaders, 

applicators)

Yes An updated occupational handler assessment is likely 

required under registration review to include any 

significant changes in exposure assessment 

methodology, toxicological PODs or uncertainty 

factors.

Post-application No There is sufficient information available to assess 

post-application exposures. Updated post-application 

exposure assessments may be needed during 

Registration Review.

Residential

Handlers Yes Updated residential handler and conventional 

residential post application exposure assessments are 

expected to be needed during Registration Review. Post-application Yes

Other

Aggregate No Evaluates the combined risk from dietary and 

residential exposures.

Cumulative No Fluazifop-p-butyl has not been identified as a member 

of a cumulative group that shares a common 

mechanism of toxicity. 

Tolerances No update 

needed.

Tolerances are currently established under 40 CFR 

§180.411 for residues of fluazifop-P-butyl in/on many 

commodities. 
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Incidents Will check for 

updates

For a discussion of reported human incidents for 

fluazifop-p-butyl, see Fluazifop-Butyl & Fluazifop-Pbutyl: Tier I Review of Human Incidents.

TIMELINE

EPA has created the following estimated timeline for the completion of the fluazifop-p-butyl

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

Table 3: Registration Review for Fluazifop-p-butyl – Projected Registration Review 

Timeline

Activities Estimated Date

Opening the Docket

Open Docket and 60-day Public Comment Period December 2014

Close Public Comment February 2015

Case Development

Final Work Plan May 2015

Issue DCI July-September 2015

Data Submission July-September 2017

60-day Public Comment Period for Draft Risk Assessments3 January-March 2019

Registration Review Decision

60-day Public Comment Period for Proposed Registration 

Review Decision

October - December 2019

Registration Review Decision and Begin Post-Decision

Follow-up

2020

Total (years) 6 years

NEXT STEPS

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

and human health studies for fluazifop-p-butyl through a Data Call-In Notice, expected to be 

issued in early 2016. 

 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.