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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 etridiazole. This work plan addresses public comments received 

concerning the Preliminary Work Plan (PWP), which was posted in the etridiazole registration 

review docket (EPA-HQ- OPP-2014-0414). Etridiazole is a soil fungicide in the thiazole family 

registered for use to control primarily Pythium and Phytophthora soil water mold species. 

Etridiazole is also used to control bacteria in genus Nitrosomonas. Etridiazole is registered for 

use on field cotton, turf (golf courses), nursery stock, tobacco float bed seedling treatments, and 

greenhouse ornamentals as well as for mixing in potting soil for commercial greenhouse use. In 

addition, etridiazole has been approved for certain Special Local Need (SLN) greenhouse uses on 

tomatoes. There are currently no registered residential uses for etridiazole. 

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.1

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

UPDATES SINCE THE PWP WAS ISSUED 

There are no additional updates on etridiazole since the PWP. 

SUMMARY OF COMMENTS AND AGENCY RESPONSES 

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

opened on June 25, 2014 and closed on August 25, 2014, the Agency received six public 

comments. Regional data on the use and usage of etridiazole are provided by the College of 

Tropical Agriculture and Human Resources of the University of Hawai‘i at Mānoa (EPA-HQOPP-2014-0414-0011) and the Western Integrated Pest Management Center (EPA-HQ-OPP2014-0414-0014). Data are offered relating to the potential effects of etridiazole on threatened 

and endangered species by the Center for Biological Diversity (EPA-HQ-OPP-2014-0414-0009) 

and FIFRA Endangered Species Task Force (FESTF) (EPA-HQ-OPP-2014-0414-0012). A letter 

from the Physicians Committee for Responsible Medicine asked EPA to limit the use of testing 

on live animals where possible, and comments by registrant MacDermid Agricultural Solutions, 

 

1

 http://www.epa.gov/oppsrrd1/registration_review/ 
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Inc. outlined a proposal for how the company intends to satisfy the Agency’s list of planned data 

needs. 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 about the PWP nor all of the Agency’s 

responses. No public comments resulted in changes to the anticipated registration review data 

needs, risk assessments, or timeline from those outlined in the etridiazole PWP. Public 

comments and EPA responses in their entirety are located in the docket, EPA-HQ-OPP-2014-

0414. Summarized public comments and Agency responses related to the anticipated ecological 

risk assessment or data needs are included in the document Response to the Initial 60-Day Public 

Comment on: “Registration Review: Draft Problem Formulation for Environmental Fate, 

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

for Etridiazole (05/06/14; PC Code 084701; DP Barcode 417576).” The Agency thanks all 

commenters and will consider the information supplied by them as EPA conducts its registration 

review of etridiazole. 

 
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PLANNED DATA NEEDS 

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

Review: Draft Problem Formulation for Environmental Fate, Ecological Risk, Endangered 

Species, and Human Health Drinking Water Exposure Assessments for Etridiazole, Etridiazole 

Human Health Risk Assessment Scoping Document in Support of Registration Review, and the 

response to public comments document Response to the Initial 60-Day Public Comment on: 

“Registration Review: Draft Problem Formulation for Environmental Fate, Ecological Risk, 

Endangered Species and Human Health Drinking Water Exposure Assessments for Etridiazole 

(05/06/14; PC Code 084701; DP Barcode 417576).” The planned data needs have not changed 

from what was included in the PWP. As the Agency works toward implementing its Guidance 

for Assessing Pesticide Risks to Bees2, additional data may be required for etridiazole to assess 

non-target exposure to bees. 

Table 1: Planned Data Needs for the Etridiazole Registration Review 

Guideline 

Number3 Study Title Test 

Material 

Estimated 

Timeframe 

(Months 

from receipt 

of DCI) 

Planned Data Needs for the Parent Etridiazole

835.4300 Aerobic aquatic metabolism TGAI 24 

835.4400 Anaerobic aquatic metabolism TGAI 24 

850.1350 Mysid chronic toxicity test TGAI 12 

850.1400 Fish early life stage toxicity test 

(estuarine/marine only) TGAI 12 

850.1500 Freshwater fish life cycle toxicity test TGAI 24 

850.2100 Avian acute oral toxicity (passerine species) TGAI 12 

850.3020 Honeybee acute contact toxicity TGAI 12 

850.4100 Terrestrial plant toxicity, seedling 

emergence 

TEP 12 

850.4150 Terrestrial plant toxicity, vegetative vigor TEP 12 

850.4400 Aquatic plant toxicity test (using Lemna 

ssp.) TEP 12 

850.6100 

Environmental chemistry methods and 

associated independent laboratory 

validations4

TGAI 12 

 

2

 Guidance is available at: http://www2.epa.gov/sites/production/files/2014-

06/documents/pollinator_risk_assessment_guidance_06_19_14.pdf. 3

 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 4

 An ECM and ILV are planned as needed for soil and water. 
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Table 1: Planned Data Needs for the Etridiazole Registration Review 

Guideline 

Number3 Study Title Test 

Material 

Estimated 

Timeframe 

(Months 

from receipt 

of DCI) 

 875.2100 Dislodgeable foliar residue and turf 

transferable residues5 TEP 24 

NonGuideline Honeybee acute oral toxicity6

 TGAI 12 

NonGuideline 

Honeybee larval toxicity7

TGAI 12 

Planned Data Needs for Degradate 3-Carb-T

850.1010 Acute toxicity (freshwater invertebrates) TGAI 12 

850.1075 Fish acute toxicity test (freshwater) TGAI 12 

Planned Data Needs for Degradate 3-DCMT 

850.1075 Fish acute toxicity test (estuarine/marine) 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 etridiazole. For human health, EPA 

will conduct revised residential (non-occupational) 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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 A turf transferrable residue study is planned as a data requirement. 

6 E.g., OECD 213. 7 E.g., OECD 237. The planned DCI will require protocol submission prior to study initiation. 
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Table 2: Planned Risk Assessments for the Etridiazole 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 Degradates 3-Carb-T and 3-DCMT will be considered 

major degradates and will be characterized in the 

ecological risk assessment. 

Incidents Will check for 

updates 

For a discussion of reported ecological incidents for 

etridiazole, see page 15 of the Problem Formulation. 

A search run on March 25, 2014 of the Office of 

Pesticide Program’s internal database Ecological 

Incident Information System (EIIS) identified no 

ecological incident reports for etridiazole. 

Human Health 

Dietary 

Food No A new dietary assessment may be performed if 1) 

there are any significant changes to toxicological 

points of departure (PODs) or uncertainty factors, 2) 

EFED determines that new estimated drinking water 

concentrations (EDWCs) are necessary using updated 

models, or 3) residue chemistry review results in 

recommendations for significantly higher tomato 

tolerances than currently established. 

Drinking water No 

Occupational 

Handlers (mixers, loaders, 

applicators) 

Yes Updated quantitative handler and post-application 

occupational risk assessments (cancer and noncancer) will be performed to include updated 

exposure assessment methodology, and any revisions 

to toxicological PODs or uncertainty factors. An 

occupational risk assessment should be performed for 

the SLN greenhouse tomato use. The new chemical 

specific greenhouse handler exposure data may be 

considered for use in certain handler assessments. 

Post-application Yes 

Residential (Non-Occupational) 

Handlers No A residential handler exposure assessment is not 

required because etridiazole is only applied to use 

sites that are not treated by residential handlers; there 

are no homeowner uses. 
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Post-application Yes Etridiazole is prohibited from use on residential turf 

and lawns. However, as etridiazole may be used on 

golf course turf, adults and children may experience 

post-application dermal exposure to etridiazole as a 

result of golfing activities. An updated postapplication assessment for golfers on etridiazole 

treated turf will be performed under registration 

review since there have been significant changes in 

exposure assessment methodology since the last 

assessment (updated 2012 residential SOP). 

Other 

Aggregate No Revised aggregate risk assessments may be performed 

for etridiazole if there are any significant changes to 

toxicological PODs or uncertainty factors, or if there 

are significant changes to dietary exposure estimates, 

or if there are significant changes to post-application 

golfer exposure estimates (based on the 2012 SOPs 

and on any new TTR data), or if EPA’s 

Environmental Fate and Effect Division (EFED) has 

determined that new estimated drinking water 

concentrations (EDWCs) are necessary. 

Cumulative No Etridiazole is not a member of a cumulative group 

and no cumulative risk assessment is planned. 

Tolerances Yes Tolerances for etridiazole are established in 40 CFR 

§180.370. The tolerance for tomatoes will be reevaluated based on the residue data submitted (since 

the RED) for imported tomatoes. The tolerance 

expression will be revised to reflect current policy. 

There are currently no international maximum residue 

limits (MRLs) for etridiazole; therefore, there are no 

harmonization issues with Codex, Canada, or Mexico. 

Currently all tomato uses of etridiazole are Special 

Local Need (SLN) uses rather than Section 3 

registrations. 

Incidents Will check for 

updates 

For a discussion of reported human incidents for 

etridiazole, see page 15 of the Scoping Document and 

the Terrazole: Tier I Review of Human Incidents. 

 
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TIMELINE

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

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

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

Activities Estimated Date

Opening the Docket 

Open Docket and 60-day Public Comment Period 2014 – June 

Close Public Comment 2014 – August 

Case Development 

Final Work Plan 2014 – November 

Issue DCI 2015 Jan. - March

Data Submission 2017 Jan. - March

60-day Public Comment Period for Draft Risk 

Assessments8

2018 July – Sept. 

Registration Review Decision 

60-day Public Comment Period for Proposed 

Registration Review Decision 

2019 April - June

Registration Review Decision and Begin Post-Decision 

Follow-up 

2020 

Total (years) 6 

NEXT STEPS 

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

and human health studies for etridiazole through a Data Call-In Notice, expected to be issued in 

early 2015. 

 

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 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.