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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 prometryn. This work plan addresses public comments received concerning the Preliminary Work Plan (PWP) , which was posted in the prometryn registration review docket (EPA

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- 0032 ). Prometryn is an herbicide registered for use on vegetable crops, cotton, an d fallow ground to control broadleaf grasses and weeds. The greatest use of prometryn is on cotton, celery (85% of crop treated), carrots, and fallow ground, based on

use data from 1998 to 2011.

The Agency is implementing the registration review progra m 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, publ ic 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 stan dard. The public phase of registration review begins when the initial docket is opened for each case.

Informatio n 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 response s to th o se comments

. This section is followed by registration

review planned data needs, risk assessments expected to be conducted , and the projected registration review timeline for prometryn

. Last, there is a discussion of next steps.

UPDATES SINCE THE PWP WAS ISSUED

Pending Actions

The Ag e ncy registered new food uses of prometryn on snap beans and dill on September 11,

2013. See 78 FR 55635 for details. These were p ending when the PWP was completed

.

Data Needs

As a result of comments submitted by the prometryn registr ant, Syngenta Crop Protection, an anaerobic aquatic metabolism is no longer necessary for registration review. More details are provided in the Summary of Comments and Agency Response section of this document. In addition, Syngenta has submitted several studies to EPA since the publication of the PWP. These studies, which may address some of the data needs identified in the PWP, are currently undergoing review. O ne of the data requirements associated with the January 2010 conditional registrations for the prometryn products Caparol ® 4L (EPA Registration Number 100

- 620) and Prometryn Technical (100

- 542) , listed as outstanding in the PWP, ha s recently been fulfilled. Specifically, a stud y submitted to fulfill the guideline requirement OSCPP 870.7800 ( Im munotoxicity ) ha s been reviewed and determined to be acceptable

. However, the conditional

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

data requirements for Guidelines 850.1350 (Aquatic Invertebrate Life Cycle for Saltwater)

, 860.1300 (Nature of the Residue in Plants for carrot or another root crop)

, and 870.6200 (Acute and Subchronic Neurotoxicity) remain outstanding.

Water Quality Data

EPA Region 9 has identified water monitoring data for prometryn . These data were collected by the California Department of Pesticide Regulation through their ro utine surface water monitoring

program and may be found in the prometryn registration review docket, EPA

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- 0032. Syngenta has also submitted water monitoring data for prometryn. All of the water monitoring data for prometryn are undergoing EPA review.

Endangered Species Consultation

As mentioned in the PWP, prometryn is the subject of an ongoing formal consultation with National Marine Fisheries Service under Section 7 of the Endangered Species Act. EPA met with Syngenta Crop Protection and s taff from the National Marine Fisheries Service on March 29, 2013 to discuss this consultation and pending biological opinion regarding the effects of prometryn on Pacific salmonids. Information about this meeting may be found in docket EPA

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- 06 54, which contains information related to th is consultation

.

SUMMARY OF COMMENTS AND AGENCY RESPONSES

During the 60

- day public comment period on the Prometryn P WP , which opened on March 27,

2013 and closed on May 28, 2013 , the Agency received two public comments. Comments were submitted by the FIFRA En d angered Species Task Force (FESTF) and by Syngenta Crop Protection Corporation (Syngenta)

. The comments do not address the timeline described in the PWP, but they do address the anticipated ecologi cal and human health risk assessments and data requirements.

In the PWP, EPA solicited comments on the specific topics of environmental justice, water quality concerns, and trade irritants. The Agency received water monitoring data from both Syngenta and California’s Department of Pesticide Regulation to address wa ter quality concerns.

No comments or other information were submitted c on cerning environmental justice. EPA

received comments from Syngenta about the differences between US tolerances for prometryn and MRLs established by Canada, the European Union, and Australia. Syngenta also commented on EPA’s summary of prometryn use and usage as well as the Agency’s summary of application rates and other use parameters from current prometryn labels.

This section summarizes public comments that resulted in changes t o the anticipated registration review data needs, risk assessments, or timeline, or are of a broader regulatory nature. This section does not capture every comment or all of EPA’s responses. However, public comments and EPA responses in their entirety ar e located in the docket, EPA

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- 0032 . EPA’s response to comments related to the anticipated ecological risk assessment or data needs are in

the document

, EFED Response to Public Comments Submitted by Syngenta Crop Protection LLC Concerning the Re gistration Review of Prometryn

, while those comments relevant to the anticipated human health risk assessment or data needs are addressed in the document,4

Prometryn: Response to Comments on the Human Health Assessment Scoping Document

. Comments related t o the prometryn label data report are addressed in the document, Response to Public Comments Submitted by Syn g enta Crop Protection Concerning the Registration Review of Prometryn

.

Comments submitted by FESTF in EPA

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1. Comment: The FIFRA Endangered Species Task Force (FESTF) has submitted both an Information Management System and Nature Serve d ata to address the proximity of endangered species to prometryn uses. Syngenta, the technical registrant for prometryn, is

an FESTF membe r and is entitle d to rely on the FESTF data.

Response: The Agency thanks FESTF for its comment and will consider the Information Management System and Nature Serve data during the prometryn registration review.

Comments submitted by Syngenta Crop Protection in EPA

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2. Comment: Enclosed with this submission is data that has not been previously submitted to
EPA to address the anticipated data need for Guideline Number 835.4100, Aerobic soil

metabolism

.

Response: EPA received the referenced study/overview under MRID numbers 49139001

and 49139002

, and the stud ies are under review. Until the review is complete and the stud ies

are determined by EPA to be acceptable, the anticipated data requirement for OSCPP

Guidelin e 835.4100 remains.

3. Comment: The anticipated data need for OSCPP Guideline 835.4400, a naerobic aquatic

metabolism is being addressed with the enclosed data

. Syngenta believes that degradation of
prometryn is very likely to be long ( i.e., prometryn is essentially stable) as found under
anaerobic soil metabolism conditions (included within the new aerobic soil metabolism study
being submitted). Thus, Syngenta accepts the EPA's proposal to deem prometryn stable
under anaerobic aquatic s ediment conditions rather than conduct a new study

.

Response: EPA has received an overview of anaerobic and aerobic soil metabolism stud ies for prometryn (MRID 4913900). Based on th is information

, the Agency will assume that prometryn is stable under an aerobic aquatic sediment conditions. Therefore, the anticipated data requirement for an anaerobic aquatic metabolism study is no longer needed for the prometryn registration review.

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. Comment: Based on the qualitatively similar metabolic profiles demon strated in cotton, celery and rice, there is no reason to believe that the carrot metabolism study will indicate the need for a ruminant feeding study. Should the carrot study reveal a metabolic profile with qualitatively significant differences, we would like to discuss the appropriateness of a ruminant feeding study with EPA at that time.5

Response: EPA will evaluate the need for a ruminant feeding study after the carrot (or other root crop) metabolism study 2 is submitted and reviewed. To this end, Syngenta is encouraged to submit the carrot metabolism study as soon as possible. In the interim, the Agency plans to include the ruminant feeding study in the registration review data call

- in (DCI) to ensure that

these data will b e available should they be needed for the registration review.

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. Comment: We have evaluated the MRLs established in the US, Canada, EU, and Australia

, and have compiled this information in Appendix 1.

Response: The Agency appreciates this informat ion. EPA will work to harmonize US tolerances with MRLs and minimize trade irritants during the prometryn registration review.

PLANNED DATA NEEDS

Table 1 below summarizes the planned data needs for prometryn based on the August 16, 2013 document, EFED Response to Public Comments Submitted by Syngenta Crop Protection LLC Concerning the Registration Review of Prometryn

, the March 19, 2013, EFED Registration Review Preliminary Problem Formulation for Prometryn

, and the February 28, 2013

, Prometryn

Human

- He alth Assessment Scoping Document in Support of Registration Review

. The table has been updated since the PWP to reflect changes resulting from public comments

. The anaerobic aquatic metabolism study listed in the PWP and ecological problem formulation document is no longer needed.

Table 1: Planned Data Needs for the Prometryn Registration Review

Guideline

Number * Study Title Test Material Estimated

Timeframe

(Months from receipt of DCI)

Data Needs for Prometryn (parent)

835.4100 Aerobic soil metabolism TGAI or

PAIRA 24

835.4300 Aerobic aquatic metabolism TGAI or

PAIRA 24

8 50 .6100 Environmental Chemistry Methods and Associated

Independent Laboratory Validation in W ater and

S oil TGAI 12

860.1480 Magnitude of the Residue

– Meat/Milk TGAI 24

870.3465 28

- D ay Inhalation Study

– Rat TGAI 12

875.2100 Dislodgeable Foliar Residue Study TEP 12

Non

GDLN ORD Study Method EPA 600/R

- 099

- 064. Chronic

Freshwater Sediment Testing ( Chironomus dilutus

or C. tentans TGAI 24

2 Although EPA has received an acceptable carrot field trial study for prometryn, the conditional data requirement for a carrot metabolism study (Guideline 860.1300) remains outst anding.6 Table 1: Planned Data Needs for the Prometryn Registration Review

Guideline

Number * Study Title Test Material Estimated

Timeframe

(Months from receipt of DCI)

Non

GDLN ORD Study Method EPA 600/R

- 099

- 064. Chronic

Freshwater Sediment Testing ( Hyallela azteca ) TGAI 24

Non

GDLN ORD Study Method EPA 600/R

- 099

- 020. Chronic

Estuarine/Marine Sediment Testing ( Leptocheirus plumulosus ) TGAI 24

Data Needs for the Prometryn Degradate Hydroxypropazine (GS

- 11526)

850.1010 Acute toxicity freshwater invertebrates Degradate 12

850.4400 Aquatic plant toxicity test using Lemna spp Degradate 12

850. 4 5 00 Algal toxicity 1 Degradate 12

TGAI = technical grade active ingredient; TEP = typical end

- use product ; PAIRA = pure active ingredient

radiolabeled. *On June 27, 2012, EPA announced certain revisions in harmonized guideline series 850

– Ecological Effects Tests

– including renumbering and other design ations or changes for some guideline studies. See “Final Test Guidelines; OCSPP 850 Series; Notice of Availability” 77 FR 38282, June 27, 2012

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1 Freshwater algae, Pseudokirchneriella subcapita , should be tested

.

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 prometryn

. For human health, EPA

will conduct revised dietary and occupational risk assessment s during registration review

. If toxicological endpoints or points of departure are rev ised 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 standard operating p rocedures or default exposure assumptions

.

Table 2 below summarizes the planned registration review risk assessments based on the EFED

Problem Formulation and HED Scoping Document . T he planned risk assessments have not changed from what was included in the PWP

.

Table 2 : Planned Risk Assessments for the Prometryn 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 expects to include prometryn, its unextracted residues, and the degradate hydroxypropazine (GS

11526) in the anticipated ecological risk assessment. EPA expects to consider slightly different residues for plants and animals. See page 32 of the problem

formulation for details.7

Planned Risk Assessments for the Prometryn Registration Review Type of Risk Assessment Conduct? Notes

Incidents Will check for updates EPA has received reports of crop damage, other

incidents to nontarget plants, and fish kills associated with exposure to prometryn; these are summarized on pages 29 and 30 of the Problem Formulation.

Human Health Dietary

Food Yes EPA expects to revise the 2009 dietary risk assessment for food and drinking water as part of a pending registration decision. The Agency may rely on this revised dietary assessment for registration review. Drinking water Yes EPA anticipates revising estimates of prometryn residues in drinking water. Because there is limited information regarding the toxicity of a major degradate, hydroxypropazine (GS

- 11526), EPA intends to include it as a residue of concern for drinking water along with the parent compound. Occupational Handlers (mixers, loaders, applicators) Yes EPA may evaluate occupational risks associated with dry flowable (DF) formulations of prometryn . EPA expects to evaluate post

- application risks for all

formulations. Post

- application Yes

Residential

Handlers No No residential uses are currently registered for
prometryn ; therefore, no residential handler or post

application assessments are necessary

. Post

- application No

Other Aggregate Yes Evaluates the combined risk from dietary and residential exposures. Any aggregate assessment for prometryn would be limited to residues in food and

water.
Cumulative No Although prometryn is a triazine, and certain triazine pesticides were identified as a common

- mechanism group (CMG), it has been excluded from the triazine CMG because it does not share the toxicity profile of

the CMG triazines.

Tolerances Yes The tolera nce expression for prometryn in 40 CFR §180.222 needs to be updated to reflect current Agency policies and to ensure that it covers the prometryn metabolites and degradates of concern.

Incidents Will check for updates At this time, there does not appear to be a concern for

human poisonings, based on the low frequency and severity of incident cases reported for prometryn 3

.

3 See the November 13, 2012 memo, Prometryn: Review of Human Incidents

, for details.8

TIMELINE

EPA has created the following estimated timeline for the completion of the prometryn registration review in Table 3 below

. The projected timeline has been updated since the PWP to
reflect impacts of recent Agency actions shortening the timeframe between the FWP and DCI issuance and adding a quarter between posting of preliminary risk assessments (PRAs) and proposed decisions.

Table 3 : Projected Registration Review Timeline for Prometryn

Activities Estimated Dat e Opening the Docket Open Docket and 60

- day Public Comment Period 2013

– March (completed)

Close Public Comment 2013

– May (completed)

Case Development

Final Work Plan 2013

– September

Issue DCI 201 3

– Oct

- Dec

Data Submission 201 5

– Oct

- Dec

6 0

- day Public Comment Period for Draft Risk Assessments 4 2017

– April

- June Registration Review Decision

60

- day Public Comment Period for Proposed Registration

Review Decision 201 7

– Oct

- Dec

Registration Review Decision and Begin Post

- Decision Follow

up 2019

Total (years) 6

NEXT STEPS

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

and human health studies for prometryn through a DCI , expected to be issued in late 2013.

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 6 0 calendar day public comment period generally for draft risk assessments.