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I NTRODUCTION

This is the Environm ental Protection Agency’s (EPA or the Agency ) Final Work Plan (FWP) for the registration review of chlorothalonil. This work plan addresses public comments received concerning the Preliminary Work Plan (PWP) , which was posted in chlorothalonil’s registration review docket (EPA

- HQ

- OPP

- 2011

- 0840 ). Chlorothalonil i s registered for a variety of conventional uses, including food and ornamental crops in both agricultural and residential sites.

Additional conventional uses include non

- residential turf and forest nursery trees. Chlorothalonil is also registered as an ant imicrobial pesticide for use as an industrial and consumer wood preservative, in the manufacture of fungicidal/mildewcidal/agalcidal paints, stains, and coatings, and in many industrial and building products such as caulks, sealants, adhesives, coatings,

c oncrete blocks and surfaces, emulsions, grouts, plaster and stucco.

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

pes ticide every 15 years to determine whether it continues to meet the FI FRA 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 abili ty 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.

Informatio n on this program i s provided on the Agency’s website 1

.

The FWP begins with any up dates 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 response s to th o se comments

. This section is followed by

chlorothalonil’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

The PWP list of data requirements for antimicrobial uses included some incorrect guideline numbers, which have been corrected in this FWP. The PW P included guideline numbers 850.3110, 850.3220, 850.3240, and 850.3280. The correct guideline numbers are 835.3110, 835.3220, 835.3240, and 835.3280.

SUMMARY OF COMMENTS AND AGENCY RESPONSES

During the 60

- day public comment period on the chlorothalonil Preliminary Work Plan , which opened on March 28, 2012 and closed on May 29, 2012, the Agency received eleven public

submissions

. Comments were submitted by several concerned citizens, several California water quality control groups, the California Rural L egal Assistance Foundation (CRLAF) , FIFRA Endangered Species Task Force, Pesticide Action Network of North America (PANNA), as well as two registrants, Sipcam Agro USA and Syngenta Crop Protection

. The comments do not

1 http://www.epa.gov/oppsrrd1/registration_review/3

address the timeline described in the PWP, but they do address the planned ecological and human health risk assessments and data requirements , as well as general concern over the effects

of chlorothalonil . In the PWP, EPA also solicited comments on the specific topics of environmental justice, water quality concerns

, trade irritants and impurities . Water quality concerns were raised by the California Central Valley Regional Water Quality Control Board, California Stormwater Quality Association, and San Francisco Bay Regional Water Control

Board , as well as some concerned citizens. Environmental justice concerns were raised by

CRLAF.

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 registration review data needs, risk assessments, or timeline, or are o f a broader regulatory nature and not captured in the separate EPA response documents

. Public comments and EPA responses in their entirety are located in the docket, EPA

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- 2011

- 0840 . Summarized public comments and Agency responses related to the anticipated ecological risk assessment

, data

needs , and water quality concerns are in the Chlorothalonil Registration Review Problem

Formulation

—

Environmental Fate and Effects D ivision's Response to Public Comments, while

those relevant to the anticipated human health risk assessment

, data needs , and environmental justice concerns are in the Chlorothalonil: Response to Comments on the Human Health Assessment Scoping Document and Preliminary Work Plan

.

Comments submitted by Sipcam Agro USA, Inc. in EPA

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- 2011

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- 0015

1. Comment: Sipcam believes that spraying and dipping of pressure treated lumber is rare and uneconomical. The registrant also provides other additional information on their understanding of chlorothalonil used as a wood preservative.

Response: The Agency is required to reevaluate all registered uses associated with each active ingredient u ndergoing registration review. To minimize the potential for EPA to overestimate risk, registrants are encouraged to submit requests to amend labeling that reflects only supported uses. Upon receiving amended labels, the Agency can reconsider the anticipated risk assessment needs for the wood preservative use patterns.

2. Comment: Sipcam provided citations for existing public literature studies on the leaching of chlorothalonil from treated wood and requested guidance with regards on the methods and substrates that should be used to conduct the leaching studies anticipat ed to be required.

Response: The Agency encourages the registrants to submit relevant studies and applicable waivers in response to the data call

- in associated with this registration review. At that time, the Agency will review the information to determi ne if the wood leaching data requirement is ad equately met and can be waived. In the event the literature studies are not sufficient, the Agency recommends that the registrant conduct the study according

to the AWPA E11

- 06 method for addressing leaching fr om wood submerged in water. The Agency has clarified the recommended study method in this FWP

.4

3. Comment: “The levels of HCB in currently registe red technical products are well

established: current technical products are produced to a specification of <40p pm HCB. Sipcam Agro USA, Inc. has chlorinated dioxin/furan data for its registered sources of chlorothalonil tech and intends to submit this data to the Agency, at the latest, at the time of Data Call In (DCI).”

Response: The Agency encourages the registrants to submit relevant information at any time or, at the very latest, at the time of the data call

- in associated with this registration

review.

Comment submitted by FIFRA Endangered Species Task Force (FESTF) in EPA

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OPP

- 2011

- 0840

- 0016

4. Comment: The FIFRA Endangered Species Task Force (FESTF) submitted a comment

tha t the Agency should ensure any company who is a registrant for chlorothalonil, but not a member of FESTF (or a company having met its data compensation obligations) provide a formal offer

- to

- pay to FESTF in conjunction with their support of the active ingredient.

Response: The Agency thanks FESTF for its comment and will consider this information as it conducts the registration review process and makes its registration review decision.5

PLANNED DATA NEEDS

The table below summarizes the planned data needs for chlorothalonil based on the March 22

, 2012 Registration Review

– Preliminary Problem Formulation for the Ecological Risk

Assessment and Drinking Water Exposure Assessment of Chlorothalonil and March 13, 2012

Chlorothalonil

- Human Health Assessment Scoping Document in Support of Registration

Review

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

.

Planned D ata Ne eds for the Registration Review of Chlorothalonil

Conventional and Antimicrobial Uses

Guideline

Number Study Title Test Material Estimated

Timeframe

(Months from receipt of DCI)

835.1230 Adsorption/desorption batch equilibrium TGAI 12

835.1240 Soil column leaching TGAI 12

835.2120 Hydrolysis TGAI 12

835.2240 Aqueous photolysis TGAI 12

835.4100 Aerobic soil metabolism TGAI 24

835.4200 Anaerobic soil metabolism TGAI 24

835.4300 Aerobic aquatic metabolism TGAI 24

835.4400 Anaerobic aquatic metabolism TGAI 24

850.1075 S altwater fish acute toxicity TGAI 12

850.1350 Saltwater invertebrates life cycle TGAI 12

850.1400 Saltwater fish early life stage TGAI 12

850.1735 Freshwater invertebrate acute whole sediment

toxicity TGAI 12

850.1740 Saltwater invertebrate acute whole sediment

toxicity TGAI 12

870.3465 90

- day inhalation toxicity (rat) TGAI 24

Planned D ata Needs for the Registration Review of Chlorothalonil

Conventional Uses Only

Guideline

Number Study Title Test Material Estimated

Timeframe

(Measured

in Months

from DCI Receipt)

835.2370 Air photolysis TGAI 12

835.6100 Terrestrial field dissipation TGAI 24

835.8100 Field volatility TGAI 126

850.4100 Seedling emergence, Tier II TGAI 12

850.4150 Vegetative Vigor, Tier II TGAI 12

850.2100 Acute avian oral, passerine 2 TGAI 12

860.1360 Multiresidue method recovery data SDS

- 3701 12

870.6200 Acute neurotoxicity TGAI 12

870.7800 Immunotoxicity TGAI 12

Non

guideline study (Special Study) Avian acute inhalation 3 TGAI

12

Planned D ata Needs for the Registration Review of Chlorothalonil

Antimicrobial Uses Only

Guideline

Number Study Title Test Material Estimated

Timeframe

(Measured

in Months

from DCI Receipt)

835.1110 Activated sludge sorption isotherm TGAI 12

8 35 .3110 Ready biodegradation 4 TGAI 12

850.6800 Modified activated sludge respiration

inhibition 4 TGAI 12

8 35 .3220 Porous pot 4 TGAI 12

8 35 .3240 Simulation tests

— aerobic sewage treatment:

A

. activated sludge 4 TGAI 12

8 35 .3280 Simulation tests to assess the biodegradability

of chemicals discharged to wastewater 4 TGAI 12

2 The anticipated DCI will provide that a protocol must be submitted for review and approval by the Agency prior to initiating this study.

3 The anticipated DCI will provide that a protocol must be submitted for review and approval by the Agency prior to

in itiating this study.

4 The results of the Activated Sludge Respiration Inhibition Test (ASRI) expected to be required will determine which of these four biodegradation tests would be anticipated to be required. If the ASRI test EC50 is less than or equal to 20 mg/L, then either the (i)Biodegradation in Activated Sludge Study or (ii) Simulation Test

– Aerobic Sewage Treatment: A. Activated Sludge Units or (iii) the Porous Pot Test would be anticipated to be required. If the ASRI test EC50 is greater than 2 0 mg/L, then the DCI expected to be issued would provide that the registrant would choose to conduct either: (i) Ready Biodegradability or (ii) a) Biodegradation in Activated Sludge or b) Simulation

Test

– Aerobic Sewage Treatment: A. Activated Sludge Unit s or c) the Porous Pot Test. If the Ready Biodegradability study is conducted and passes, then no further testing would be expected to be required. If, however, the antimicrobial fails the Ready Biodegradability study, then the a) Biodegradation in Activ ated Sludge or b) Simulation Test

– Aerobic Sewage Treatment: A. Activated Sludge Units, or c) the Porous Pot study would be expected to be required.7

875.1400 Indoor i nhalation exposure 5 TGAI/TEP 12

875.1600 Exposure monitoring data reporting TGAI/TEP 12

875.1700 Product Use Information TGAI/TEP 12

875.2300 Surface residue dissipation 6 TGAI/TEP 24

Non

guideline study

(Special Study) Wood leaching study (AWPA E11

- 06) 7 TEP 24

RISK ASSESSMENTS FOR REGISTRATION REVIEW

During registration review, t he Agency will conduct a comprehensive ecological risk assessment, including an endangered species assessment, for all uses of chlorothalonil. For human health,

EPA will conduct revised residential and occupational risk assessment s 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 assessment s
, as well as any changes to the S tandard O perating P rocedures or default exposure assumptions

.

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

March 22 , 2012 Registration Review

– Preliminary Problem Formulation for the Ecological Risk Assessment and Drinking Water Exposure Assessment of Chlorothalonil and the March 13, 2012

Chlorothalonil. Human

- Health Assessment Scoping Document i n Support of Registration

Review. The planned assessments have not changed from what was included in the PWP

.

Planned Risk Assessments for the Registration Review of Chlorothalonil

– Conventional

and Antimicrobial Uses

Type of Risk Assessment Conduct ? Notes

Eco logical and Environmental Fate Comprehensive ecological (species to be assessed

include terrestrial and aquatic organisms ), including endangered species Y

5 The Agency anticipate s the need to require inhalation exposure studies for the following scenarios: open

- pour liquids during material preservation; open

- pour wettable powders during material preservation; brush/roller application of treated paints; airless sprayer application of treated paints; and dip, spray, and pressure treatment of

wood

. 6 Anticipated to be required to assess r esidential exposure to pressure

- treated wood . The anticipated DCI will provide that a protocol must be submitted for review and approval by the Agency prior to initiating this study.

7 The Agency recommends that the registrant conduct the wood leaching study according to AWPA E11

- 06 method for addressing leaching from wood submerged in water. The anticipated DCI will provide that a protocol must be submitted for review and approval by the A gency prior to initiating this study.8

Incidents Y For a discussion of chlorothalonil’s reported ecological incidents, see page 69 of the

Problem Formulation.

Human Health Dietary

Food TBD If there are no changes to the estimated drinking water concentrations (EDWCs), toxicological endpoints or points of departure, then results from the last dietary assessment will be used for registration

review. Drinking water TBD If there are no changes to the EDWCs, toxicological endpoints or points of departure, then results from the last dietary assessment will be used for registration

review. Occupational Handlers (m ixer s, loader s, applicators ) Y

Post

- application Y

Residential

Handlers Y

Post

- application Y

Other Aggregate TBD E valuates the combined risk from dietary and residential exposures. If there are no changes to toxicological endpoints or points of departure or EDWCs , then results from the last dietary assessment will be used for registration review.

Cumulative N

Tolerances Y The Agency anticipates revising the tolerance expression for chlorothalonil in 40 CFR §180.275(a)(1) and §180.275(a)(2) during registration review to ensure that it appropriately covers the metabolites and degradates of chlorothalonil and that it specifies the residu es to be measured in each commodity.

Incidents Y For a discussion of chlorothalonil’s reported human incidents, see page 20 of the Scoping

Document.9

TIMELINE

EPA has created the following estimated timeline for the completion of chlorothalonil registration review

. The projected timeline has not changed since the PWP

.

Registration Review for Chlorothal on il

– Projected Registration Review Timeline

Activities Estimated Date Opening the Docket Open Docket and 60

- day Public Comment Period 2012

– March

- Completed

Close Public Comment 2012

– May

- Completed Case Development

Final Work Plan 2012

– Aug.

– Sept.

- Completed

Issue DCI 2013

– April

– June

Data Submission 2015

– April

– June Open 30

- day Public Comment Period for Draft Risk Assessments 2016

– Oct.

– Dec.

Close Public Comment Period 2017

– Jan.

– March Registration Review Decision Open 60

- day Public Comment Period for Proposed Registration

Review Decision 2017

– April

– June

Close Public Comment Period 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 chlorothalonil through a data call

- in, expected to be issued in 2013.