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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 acibenzolar-S-methyl (hereafter, referred to as acibenzolar). This work 

plan addresses public comments received concerning the Preliminary Work Plan (PWP), which 

was posted in the acibenzolar registration review docket (EPA-HQ-OPP-2013-0755).

Acibenzolar is registered for use to protect plants against invading pathogens by inducing a 

natural defense reaction that enhances the plants ability to ward off disease. It is registered for

use on a number of leafy and fruiting vegetables crops and tobacco for the control or suppression 

of downy mildew, black rot, white rust, bacterial leaf spot and speck, and blue mold.

Acibenzolar is also registered for use in commercial seed treatment operations for protection 

against certain early season seed and seed-borne nematodes in cotton and sunflower. It is also 

used on sod farms, golf courses, professional and collegiate athletic fields, and lawns around 

commercial and industrial buildings to control turf diseases.

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 acibenzolar. Lastly, there is a discussion of next steps.

UPDATES SINCE THE PWP WAS ISSUED

There are no additional updates on acibenzolar since the PWP.

SUMMARY OF COMMENTS AND AGENCY RESPONSES

During the 60-day public comment period on the Acibenzolar Preliminary Work Plan, which 

opened on December 20, 2013 and closed on February 18, 2014, the Agency received six unique

public comments. Comments were submitted from non-governmental organizations, 

universities, and the acibenzolar registrant, Syngenta. The comments do not address the timeline 

described in the PWP, but they do address the planned ecological risk assessment 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.

 

1 http://www.epa.gov/oppsrrd1/registration_review/
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This section does not capture every comment made about the PWP nor all of the Agency’s 

responses. Summarized below are public comments that are of a broad regulatory nature. None 

of the comments resulted in changes to the anticipated registration review data needs, risk 

assessments, or timeline. Public comments and EPA responses in their entirety are located in the 

docket, EPA-HQ-OPP-2013-0755. Summarized public comments and Agency responses related 

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

Comments on the Acibenzolar-S-methyl Registration Review Problem Formulation. 

Comment submitted by the University of Hawai‘i in EPA-HQ-OPP-2013-0755-0011.

1. Comment: Acibenzolar is important for golf course turf maintenance in Hawai‘i, particularly 

for dollar spot control.

Comment submitted by Syngenta Crop Protection, LLC in EPA-HQ-OPP-2013-0755-0012.

2. Comment: Corrected label information and additional use information was provided.

Comment submitted by Washington State University Tri-Cities in EPA-HQ-OPP-2013-

0755-0013.

3. Comment: Information about the potential importance of acibenzolar in Integrated Pest

Management (IPM) programs was provided for cranberry, and for lettuce, pepper, spinach, 

and tomato when used in conjunction with fungicides.

Comment submitted by the FIFRA Endangered Species Task Force (FESTF) in EPA-HQOPP-2013-0755-0014.

4. Comment: FESTF noted that registrants that are not currently members must offer to pay or 

develop their own data. However, Syngenta is a member of FESTF.

Comment submitted by the Arizona Pest Management Center in EPA-HQ-OPP-2013-0755-

0015.

5. Comment: Acibenzolar is an effective product against downy mildew. In Arizona, it is 

primarily used in spinach, but is also being used in chili.

Response to comments 1-5: The Agency appreciates the information provided and will take it 

into consideration during the registration review of acibenzolar.

PLANNED DATA NEEDS

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

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

Endangered Species, and Drinking Water Exposure Assessments for Acibenzolar-S-methyl;
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Acibenzolar-S-methyl: Human Health Risk Scoping Document in Support of Registration 

Review; and Response to Public Comments on the Acibenzolar-S-methyl Registration Review 

Problem Formulation. The planned data needs have not changed from what was included in the 

PWP. However, the guideline number for the larval honeybee acute oral toxicity study was 

listed incorrectly in the PWP as 850.3020 and the estimated timeframe was listed in the PWP as 

12 months. The FWP has been corrected to reflect the correct information.

Table 1: Anticipated Data Needs for the Acibenzolar Registration Review

Guideline 

Number2 Study Title1

Test Material

Estimated 

Timeframe

(Months from 

receipt of DCI)

Anticipated Data Needs for the Parent Acibenzolar

850.4100 Seedling emergence (Tier II); wheat and tomato TEP 12

850.4400 Aquatic plant growth toxicity (Tier II) TGAI 12

NonGDLN Larval honeybee acute oral toxicity TGAI 24

850.6100 Environmental chemistry methods and associated 

independent laboratory validations for water

TGAI 12

Anticipated Data Needs for the CGA-210007 Degradate

850.2300 Avian reproduction test (bobwhite quail) CGA-210007 24

850.6100 Environmental chemistry methods and associated 

independent laboratory validations for water

CGA-210007 12

Outstanding Data Requirements from Conditional Registration3

850.6100 Environmental chemistry methods and associated 

independent laboratory validations for soil CGA-210007 In review

850.5400 Aquatic plant growth (freshwater diatom, 

saltwater diatom, cyanobacteria )

TGAI In review

850.2100 Avian acute oral toxicity (passerine) TGAI In review

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

 

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

3 The studies listed in this section were previously submitted as conditions of registration in April 2013 and are still 

outstanding. These studies will not be included in the anticipated Registration Review DCI because they are 

already required as conditions of registration.
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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 acibenzolar.

For human health, EPA may conduct revised dietary, residential, and occupational risk 

assessments during registration review. If toxicological endpoints or points of departure are 

revised, they will be considered in any updated 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 Acibenzolar 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 Acibenzolar-S-methyl and the major degradate of concern, 

CGA-210007, will be considered the stressors of concern in 

the ecological risk assessment. 

Incidents Will check for 

updates

For a discussion of reported ecological incidents for 

acibenzolar, see page 15 of the Problem Formulation.

Human Health

Dietary

Food N Updated dietary exposure assessments may be conducted if 

there are any significant changes to the toxicological pointsof-departure (PODs) or Food Quality Protection Act (FQPA) 

and other uncertainty factors (UFs). 

Drinking water N If any significant changes to the estimated drinking water 

concentrations (EDWCs) may also necessitate changes to the 

dietary assessment.

Occupational

Handlers (mixers, 

loaders, applicators)

N The occupational handler assessment may need to be updated 

to reflect the most recent occupational handler surrogate 

exposure data or any significant change in exposure 

assessment methodology, toxicological PODs, or UFs.

Post-application N

Residential

Handlers N

Post-application Y A quantitative exposure/risk assessment for direct residential 

application may be necessary during registration review to 

incorporate any changes to the Agency’s policies regarding 

off-site transport.

Other

Aggregate Y Emerging policies related to pesticide drift and volatilization 

assessments may warrant changes to the existing aggregate 

risk assessment.

Cumulative N Acibenzolar is not a member of a cumulative group, so no 

cumulative risk assessment is planned.

Tolerances N The current tolerance expression as listed in the 40 

CFR§180.561 (a) has been updated to reflect current policy.

Incidents Will check for 

updates

For a discussion of reported human incidents for acibenzolar, 

see page 6 of the Scoping Document and the Acibenzolar:

Tier I Review of Human Incidents.
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TIMELINE

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

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

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

Activities Estimated Date

Opening the Docket

Open Docket and 60-day Public Comment Period December 2013 –

Completed

Close Public Comment February 2014 –

Completed

Case Development

Final Work Plan May 2014 –

Completed

Issue DCI 2014 July – Sept.

Data Submission 2016 July – Sept.

60-day Public Comment Period for Draft Risk Assessments4 2018 Jan. - March

Registration Review Decision

60-day Public Comment Period for Proposed Registration Review 

Decision

2018 July – Sept.

Registration Review Decision and Begin Post-Decision Follow-up 2019

Total (years) 6

4 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.

NEXT STEPS

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

effects studies for acibenzolar through a Data Call-In Notice, expected to be issued in September 

2014. 

 

4 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.