2 

### Diuron Prel iminary Work Plan

– Table of Contents

OVERVIEW

................................ ................................ ................................ ................................ ... 4

ANTICIPATED DATA NEEDS

................................ ................................ ................................ .... 5

STATUTORY AND REGULATORY AUTHORITY

................................ ................................ ... 9

CHEMICAL FACTS

................................ ................................ ................................ ...................... 9

USE AND USAGE INFORMATION

................................ ................................ .......................... 10

RECENT ACTIONS

................................ ................................ ................................ ..................... 12

ANTICIPATED RISK ASSESSMENTS FOR REGISTRATION REVIEW

.............................. 13

TIMELINE

................................ ................................ ................................ ................................ .... 17

NEXT STEPS

................................ ................................ ................................ ............................... 17

Appendix

– Additional Areas Considered i n the Diuron Regist ration Review

........................ 18

References:

This Preliminary Work Plan summarize s the Environmental Protection Agency's current position based on the following documents:

1. Diuron: Registration Review Problem Formulation for the Environmental Fate, Ecological Risk, Endangered Species, and Drinking Water Assessments

. Jewett, F.; Lowit, M.; Breithaupt, J.; Bays, D.; Mostaghimi, S

. December 16 , 2015

.

2. Diuron. Human Health Assessment Scoping Document in Support of Registration Review

. Middleton, K; Figueroa, Z; Drew, W; Dole, T

. December 9, 2015

.

3. Diuron: Tier 1 (Scoping) Review of Human Incidents/Epidemiology . Recore , S; Evans, E. August 6, 2015

.

4. BEAD Chemical Profile (BCP) for Registration Review: Diuron (035505)

. Ratnayake, S; Haddad, S.; Smearman, S. November 6, 2014.

5. Diuron (035505) Screening Level Usage Analysis ( SLUA )

. March 24, 2015

.3 6. Diuron (035505) EFED Table 1 Report

. November 12, 2014.

7. Diuron (035505) HED Master Label Report. November 12, 2014.

8. Diuron (035505) AD Label Data Report . November 12, 2014.

These and other supporting documents for the diuron registration review case may be found in
the docket EPA

- HQ

- OPP

- 2015

- 0077 a t http://www.regulations.gov

.4 OVERVIEW

The docket for diuron is now open , initiating the first public comment period for this registration
review (docket number EPA

- HQ

- OPP

- 2 015

- 0077 )

. Diuron is registered for conventional pesticide uses as a pre

- and post

- emergent herbicide to control annual and perennial broadleaf and grassy weeds in a variety of agricultural crops, ornamental plants , and non

- crop sites and for
conventional uses as an algaecide in commercial fish production

. It is also registered for
antimicrobial uses as a mildewcide and as an algaecide in paints and stains

. Registered residential uses include ponds, aquariums, and paints. This Preliminary Work Plan (PWP) document explains what EPA's Office of Pesticide Programs knows about diuron

, highlighting anticipated data and assessment needs, identifying the types of information that would be especially useful to the Agency in conducting the review , and providing an anticipated timeline

f

or completing the registration review for diuron

.

The registration review process was designed to include a public participation component to solicit input from interested stakeholders. The Agency intends, b y sharing this information in the docket, to in form the public of what it knows about diuron and what types of new data or other information would be helpful for the Agency to receive as it moves toward a decision on diuron

. The Agency encourages all interested stakeholders to review the PWP and Appendix and to provide comments and additional information that will help the Agency’s decision

- ma king process for this chemical. In addition to general areas on which persons may wish to comment,
there are some areas identified in the PWP and Append ix about which the Agency specifically
seeks comments and information. Interested stakeholders could include: environmental non

profit or interest groups; pesticide manufacturers; agricultural labor or commodity groups; commercial, institutional, resident ial, and other users of pesticides; or the public at large.

The PWP begins by listing the anticipated data needs for diuron

. Next, it discusses the statutory and regulatory authority for R egistration R eview. Then the document provides chemical facts,

use and usage information, recent actions, the anticipated risk assessments, and a projected registration review timeline for diuron

. Finally, the Appendix to this document includes identification and discussion of some areas that are considered generally in R egistration R eview along with some additional chemical case

- specific information.5 ANTICIPATED DATA NEEDS

Table 1 below summar izes anticipated data needs for diuron

. For additional discussion of the anticipated data needs, see the Diuron: Registration R eview Problem Formulation for the Environmental Fate, Ecological Risk, Endangered Species, and Drinking Water Assessments and Diuron. Human Health Assessment Scoping Document in Support of Registration Review

.

Table 1: Anticipated Data Needs for the Diuron Registration Review

Guideline

Number 1 Study Title Test
Material Estimated
Timeframe

(Months

from receipt of DCI) Study is

needed to support the
antimicrobial
uses of diuron (Y es /N o ) Study is

needed to support the
conventional
uses of diuron (Y es /N o )

Anticipated Data Needs for the Parent Diuron

850.6100 Independent laboratory validation (ILV) report for analytical method in soil (ECM not required) TGAI 12 N o Y es

850.6100 Independent laboratory validation (ILV) report for analytical method
in water (ECM not required) TGAI 12 N o Y es

850.1400 Estuarine/marine fish early

- life stage toxicity TGAI 12 Y es Y es

850.2100 Avian oral toxicity (passerine species) TGAI 12 N o Y es

850.2300 Avian reproduction with an upland game species TGAI 24 N o Y es

850.4100 Terrestrial plant toxicity, seedling

emergence 2 TEP 12 N o Y es

850.4150 Terrestrial plant toxicity, vegetative vigor 3 TEP 12 N o Y es

1 On June 27, 2012, EPA announced certain revisions in harmonized guideline serie s 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

2 Valid endpoints have been submitted for Oilseed Rape, Sugar Beet, Tomato, Onion, and Wheat. Study must

include the correct n umber and type of test species as specified by guideline 850.4100

. 3 Valid endpoints have been submitted for Pea, Oilseed Rape , Onion, Sorghum and Wheat. Study must include the correct number and type of test species as specified by guideline 850.415 0

.6 Table 1: Anticipated Data Needs for the Diuron Registration Review

Guideline

Number 1 Study Title Test
Material Estimated
Timeframe

(Months

from receipt of DCI) Study is

needed to support the
antimicrobial
uses of diuron (Y es /N o ) Study is

needed to support the
conventional
uses of diuron (Y es /N o )

850.4500 Aquatic plant toxicity study with freshwater diatom, Navicula pelliculosa TGAI 12 Y es Y es

850.4500 Aquatic plant toxicity study with the marine diatom, Skeletonema

costatum TGAI 12 Y es Y es

850.4550 Aquatic plant toxicity study with blue

- green alga, Anabaena flos

aquae TGAI 12 Y es Y es

870.6200 Acute oral neurotoxicity study (rat) TGAI 12 Y es Y es

Non

GDLN (OECD

213) Tier I honeybee adult acute oral toxicity TGAI 12 N o Y es

Non

GDLN Tier I honeybee adult chronic oral toxicity TGAI 12 N o Y es

Non

GDLN Tier I honeybee larval acute oral toxicity TGAI 12 N o Y es

Non

GDLN Tier I honeybee larval
chronic oral toxicity TGAI 12 N o Y es

Non

GDLN Tier II residue in pollen and nectar 4 TEP 24 N o Y es

Non

GDLN Tier II semi

- field testing for honeybee toxicity (tunnel/enclosure or colony feeding) 4 TEP 24 N o Y es

850.3040 Tier III field testing for pollinator toxicity 4 TEP 24 N o Y es

Non

GDLN Special leaching study for paint TGAI 12 Y es N o

4 The need for these anticipated data requirements is contingent on results of the tier 1 bee studies (including acute oral toxicity to adult honey bees, acute oral toxicity to larval honey bees, chronic oral toxicity to adult honey bees,
and chronic oral t oxicity to larval honey bees).7 Table 1: Anticipated Data Needs for the Diuron Registration Review

Guideline

Number 1 Study Title Test
Material Estimated
Timeframe

(Months

from receipt of DCI) Study is

needed to support the
antimicrobial
uses of diuron (Y es /N o ) Study is

needed to support the
conventional
uses of diuron (Y es /N o )

860.1340 Residue analytical method (ILV of the
livestock enforcement method) TGAI 12 N o Y es

860.1360 Multi

- residue method (MRM testing for
diuron in livestock commodities) TGAI 12 N o Y es

875.1400 Inhalation Indoor Exposure Study 5 TEP 24 Y es N o

875.2100 Dislodgeable Foliar Residue (DFR) Dissipation Study TEP 12 N o Y es

Anticipated Data Needs for the DCPMU Degradate

850.6100 Independent laboratory validation (ILV) report for analytical method in soil (ECM not required) DCPMU Degradate 12 N o Y es

850.6100 Independent laboratory validation (ILV) report for analytical method in water (ECM not required ) DCPMU Degradate 12 N o Y es

850.4500/

850.4550 Algal/cyanobacteria toxicity testing with
the non

- vascular plant species most sensitive
to diuron DCPMU Degradate 12 Y es Y es

Anticipated Data Needs for the mCPDMU Degradate

850.6100 Independent laboratory validation (ILV) report for analytical method in water (ECM not required) mCPDMU Degradate 12 N o Y es

5 Data is anticipated to be required for the following scenarios for antimicrobial uses: (1) Mixing/loading liquids for material preservation and (2) Brush/roller and airless sprayer application of preserved paints.8 Table 1: Anticipated Data Needs for the Diuron Registration Review

Guideline

Number 1 Study Title Test
Material Estimated
Timeframe

(Months

from receipt of DCI) Study is

needed to support the
antimicrobial
uses of diuron (Y es /N o ) Study is

needed to support the
conventional
uses of diuron (Y es /N o )

850.450 0/

850.4550 Algal/cyanobacteria toxicity testing with
the non

- vascular plant species most sensitive
to diuron mCPDMU Degradate 12 Y es Y es

Anticipated Data Needs for the PDMU Degradate

850.6100 Environmental chemistry method (ECM) and associated independent laboratory validation (ILV) reports for analytical
method in water PDMU Degradate 12 N o Y es

Anticipated Data Needs for the mCPMU Degradate

850.6100 Environmental chemistry method (ECM) and associated independent laboratory validation (ILV) reports for analytical
method in water mCPMU Degradate 12 N o Y es

TGAI = technical grade active ingredient; TEP = typical end

- use product9 STATUTORY AND REGULATORY AUTHORITY

The Food Quality Protection Act (FQPA) of 1996 mandated a registration review program

. All pesticides distributed or sold in the United States (U.S.) generally must be registered by the Environmental Protection Agency (EPA or the Agency), based on scientific data showing that they will not caus e unreasonable risks to human health or the environment when used as directed on product labeling. 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 pes ticides continue to meet the statutory standard of no unreasonable adverse effects to human health or the environment. Changes in science, public policy, and pesticide use practices will occur over time. Through the registration review program, the Agency periodically reevaluates pesticides to make sure that as change occurs, products in the marketplace can be used safely. Informatio n on this program is provided on EPA’s website

. 6

The Agency is implementing the registration review program pursuant to Sec tion 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. The regulations governing registration review begin at 40 CFR 155.40

. T he Agency will consider benefits information and data as required by FIFRA. The public phase of registration review begins when the initial docket is opened for each case. The docket is the Agency’s opportunity to state what it knows about the pesticide and what additional risk analyses and data or information it believes are needed to make a registration review decision. After reviewing and responding to comments and data received in th e docket during this initial comment period, the Agency will develop a F inal W ork P lan (FWP) and anticipated schedule for the registration review of diuron.

CHEMICAL FACTS

Table 2 provides a summary of the chemical facts for diuron

.

Table 2: Chemical Facts for Diuron

PC code 035505

Case Number 0046

CAS Number 330

- 54

- 1

Year first registered 1967 Pesticide Type Herbicide and algaecide (conventional ) ; algaecide and mildewcide (antimicrobial )

Chemical class Urea (Group 7)

R eregistration Eligibility Decision (R E D) 2003

Tolerance Reassessment Eligibility Decision (TRED) 2002

6 Availab le at: http://www2.epa.gov/pesticide

- reevaluation10 Table 2: Chemical Facts for Diuron

Cumulative group Not applicable. Diuron has not been identified as a member of a cumulative group that shares a common mechanism of toxicity.

40 CFR Citation Tolerances fo r the conventional uses of diuron ar e established in 40CFR §180.106[a] and [c ]. There are no tolerances or tolerance exemptions for the antimicrobial uses of diuron.

Dual

- use Diuron is registered for conventional pesticidal uses and
antimicrobial uses.

Non

- pesticidal uses There are no identified non

- pesticidal uses of diuron.

Pesticide Re

- evaluation Division, Chemical Review Manager Katherine St. Clair, Stclair.Katherine@epa.gov , 703

- 347

- 8778

Antimicrobials Division,
Chemical Review Manager SanYvette Williams

, Williams.Sanyvette@epa.gov , 703

- 305

- 7702

Registration Division

, Product Manager and
Chemical Review Manager Heather Garvie, Garvie.Heather@epa.gov , 703

- 308

- 0034 Banza Djapao, Djapao.Banza@epa.gov

, 703

- 305

- 7269

USE AND USAGE INFORMATION

Table 3 summarizes the use and usage information for diuron

. Please see the BEAD Chemical Profile (BCP) for Registration Review: Diuron (035505) in t he registration review docket for

more details

.

Table 3 : Diuron Us e and Usage Information

Summary of Use Diuron is registered for conventional uses as a pre

- and post

emergent herbicide to control annual and perennial broadleaf and grassy weeds in a variety of agricultural crops, ornamental plants

, and non

- crop sites and is registered for conventional uses as an algaecide in commercial fish production . It is also registered for
antimicrobial uses as a mildewcide and algaecide in paints and
stains . Registered residential uses include ponds, aquariums, and paint s. Use Sites Agricultural Use Sites Registered agricultural use sites include alfalfa, apples, artichokes, asparagus, bananas, barley, blueberries, cactus, caneberries, citrus, clover, corn, cotton, fish farm ponds, grapes, gooseberries, grass grown for s eed, tree nuts , mint, oats, olives, papayas, pasture, peaches, pears, peas, pineapple s , plantains, prickly pear cactus pads, sorghum, sugarcane, trefoil, triticale, wheat, and ornamental trees , flowers, s hrubs , and non

- flowering plants

.11 Table 3 : Diuron Us e and Usage Information

Non

- Agricultural U se Sites Registered non

- agricultural use sites include paints and coatings, adhesives, ornamental fish ponds , patios, paths, general outdoor

areas, picnic areas, rights

- of

- way, general uncultivated areas, agricultural cultivated areas, irrigation and drainage ditches, and
industrial sites. Registered r esidential use sites in clude ponds, aquariums, paints , patios, paths, and general outdoor areas. Summary of Usage EPA has agricultural usage data for diuron, but the available non

agricultural usage data for diuron is limited.

A gricultural Usage EPA obtained private market usage data from 1998

- 2012 on diuron agricultural usage. In the period from 1998

- 2012, usage averaged ap proximately 4.1 million pounds active ingredient (lbs. a.i.) applied annually on approximately 4.9 million acres treated. However, t he average annual agricultural usage of diuron in lbs. a.i. has decreased approximately 30 percent from the 1998

- 2003
timefr ame (4.7 million lbs

. a.i. per year) to the 2007

- 2012 timeframe (3.3 million lbs. a.i. per year). During both timeframes,

t he top two crops with the most lbs. a.i. applied were oranges a nd cotton, accounting for approximately 70 percent of total lbs. a.i. applied.

Non

- Agricultural Usage
EPA obtained limited information on diuron non

- agricultural usage from two sources, 1) the USDA’s National Agricultural Statistics Service (NASS) 2006 and 2009 Nursery and Floriculture reports and 2) proprietary Kline & Company data. Data for more recent years (2012 to present) were not available. Usage on most non

- agricultural use sites (including aquatic areas, turf and ornamentals, and use by landscape/lawn care operators) generally increase d between the early

- 200 0 s to the mid

- 2000s

, but nursery/greenhouse usage remained fairly steady

. Formulation Type(s) Diuron is formulated as a liquid, emulsifiable concentrate, dry flowable, flowable concentrate, granular, pellet/tablet, and ready

to

- use solution. Application Method(s) Diuron products can be applied usi ng ground , handheld, and
aerial equipment. It can also be applied as an additive/industrial preservation treatment and as a water treatment. Technical Registrant (s) Diuron technical registrants include E.I. DuPont De Nemours and Company, ADAMA AGAN Ltd., Drexel Chemical Company,

Lanxess Corporation, Chemstarr LLC, Redeagle International

LLC , Bayer Environmental Science, and Makhteshim Agan of North America, Inc.12 Table 3 : Diuron Us e and Usage Information

No. of Registrations As of December 2015, there are 88 Section 3 registrations 7 and 30
Section 24c registrations

. Restricted Use Diuron is not classified as a restricted use pesticide.

Guidance for Commente rs: Additi onal areas of use and usage related information requested for this registration r eview

, and of particular interest to EPA, are described below.

Conventional Uses

• Diuron labels are inconsistent with respect to the application parameters provided on the labels. The Agency requests that the registrant provide the following information for
conventional uses: maximum annual application rates per acre (lb ai/A/year) for all uses,
maximum number of applications per crop cycle or season (if appl icable) and maximum number of applications per year (all uses), and minimum application intervals (all uses). When application rates or intervals are provided in terms or season or crop cycle, they
should also be provided in terms of annual application rat es or intervals. Without further information, EPA expects to use conservative assumptions to approximate these parameters in order to conduct a quantitative risk assessment. However, the Agency will work with registrants to clarify information on diuron p roduct labels.

• C onfirmation of the following label information : sites of application ; formulations ; application methods and equipment ; maximum application rates (in terms of maximum amount of product applied per year and maximum amount of active ingredient appli ed per year) ; frequency of application, application intervals, and maximum number of applications per season ; number of seasons in a year; and geographic limitations on use

. When application rates or intervals are provided in terms or season or crop cycle, they
should also be provided in terms of annual application rates or intervals.

• Typical a pplication timing (date of first application and application intervals)

– national, state, and county

.

• Usage information for non

- agricultural uses

.

• Typical application interval (days)

.

• F oreign technical registrants not listed above who supply te chnical diuron to the US
market

.

Antimicrobial Uses

• Confirmation of the use sites and application rates listed on the labels.

• Usage i nforma tion for each of the antimicrobial uses, including use as an algaecide a nd mildewcide in paints and coatings

.

RECENT ACTIONS

Conventional Pesticidal U ses

7 Section 3 product labels can be obtained from the Pesticide Produ ct Label System (PPLS) website

( http://oaspub.epa.gov/pestlabl/ppls.home ).13 The RED for diuron was signed in September 2003, and the product reregistration process has been completed.

As of December 2015, there are two pending registration actions for conventional diuron registrations (two applications for new technical registrations which would be “me

- toos” of existing products).

Antimicrobial U ses

There is one pending registration action for an antimicrobial diuron registration

.

ANTICIPATED RISK ASSESSMENTS FOR REGISTRATION REVIEW

The most recent comprehensive human health risk assessment s for diuron were completed in

2003 in preparation for the R eregistra tion Eligibility Decision (RED) and in 2012 for a new use
request. T he most recent ecological and environmental fate risk assessment s were completed in
2003 for the RED and for the Endangered and Threatened Salmon and Steelhead Assessment, as well as in 2009 for the California Red

- legged Frog Assessment

. Findings and conclusions from
these risk assessments are summarized in the document titled Diuron: Registration Review Problem Formulation for the Environmental Fate, Ecological Risk, Endangered Sp ecies, and Drinking Water Assessments and the document titled Diuron. Human Health Assessment Scoping Document in Support of Registration Review

.

During registration review, t he Agency anticipates the need to conduct a comprehensive ecological risk assessment, including an endangered species assessment, for all conventional
uses of diuron

. T he Agency also anticipates the need to conduct an aquatic assessment for the antimicrobial uses of diuron as it leaches from paints and coatings on structures an d enters
surface waters

. For human health, EPA anticipates the need to conduct revised dietary,
residential

, occupational , and aggregate risk assessment s for the conventional uses of diuron during registration review

. Also, if formally requested by the registrant, the Agency will re

evaluate the cancer classific ation for diuron. For the antimicrobial uses of diuron, the Agency anticipates the need to conduct revised occupational and residential risk assessments. If

tox icological endpoints or points of departure are revised based on the data that are anticipated to
be required for registration review

, they will be considered in the new assessment s , as will any changes to the standard operating p rocedures or default expos ure assumptions

.

T able 4 summarizes the anticipated registration review risk assessments based on the document
titled Diuron: Registration Review Problem Formulation for the Environmental Fate, Ecological Risk, Endangered Species, and Drinking Water Asses sments and the document titled Diuron. Human Health Assessment Scoping Document in Support of Registration Review

.14 Table 4: Anticipated Risk Assessments for the Diuron Registration Review

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 Yes EFED a nticipates conducting an updated comprehensive ecological risk assessment during registration review for all conventional uses of diuron. The new assessment will incorporate the most up

- to

date modeling methodologies, updated toxicological endpoints, and data submitted under the anticipated registratio n review data call

- in.

The stressors of concern (mCPDMU and DCPMU; potentially PDMU and mCPMU) will be assumed to have similar toxicity as diuron (in the absence of data) . Furthermore, a TTR approach may be used to estimate aquatic exposure.

AD anticipates conducting an aquatic assessment for
the antimicrobial uses of diuron as it leaches from paints and coatings on structures and enters surface

waters. This is likely to be a small contribution relative to the conventional uses, but is a potenti al exposure pathway.

Incidents Will check for updates For a discussion of reported ecological incidents for
diuron , see Section 6(d) and Appendix 4 of t he
Problem F ormulation.

Human Health Dietary Dietary Yes HED anticipates conducting r evised dietary expo sure analyses for the conventional uses of diuron to reflect updated dietary exposure models and updated drinking water assessments

. Food Yes15 Table 4: Anticipated Risk Assessments for the Diuron Registration Review

Type of Risk Assessment Conduct ? Notes
Drinking water Yes EFED anticipate s conducting updated drinki ng water assessments for diuron during registration review to incorporate updated drinking water concentrations

. Diuron, mCPDMU, and DCPMU will be considered
the stressors of concern in the diuron drinking water

assessment

. The residues of concern ma y be reevaluated pending reevaluation of existing data and receipt and review of additional data for diuron or its degradation products.

The drinking water assessment will be based on modeled estimates of exposure but will also include a summary of avai lable surface and ground water monitoring data

. Occupational Handlers (mixers, loaders, applicators) Yes HED and AD anticipate conducting revised (non

cancer and cancer) occupational exposure assessments
to reflect the use of the most recent handler exposure data, the toxicity studies, and updated exposure inputs.

HED anticipates conducting updated ( non

- cancer and cancer) post

- application exposure assessments for workers conducting post

- application activities. Post

- application Yes

Residential

Handlers Yes For the aquatic uses of diuron, HED anticipates
conduct ing revised (non

- cancer and cancer)
residential handler and residential post

- application

assessment s that incorporate recently updated procedures found in the Health Effects Division’s

201 2 Standard Operating Procedures for Residential Pesticide Exposure Assessment.

For the use of diuron in paint, AD anticipates
conduct ing revised residential handler application
exposure assessment s (brush/roller and airless

sprayer

. Post

- application Yes

Other16 Table 4: Anticipated Risk Assessments for the Diuron Registration Review

Type of Risk Assessment Conduct ? Notes

Aggregate Yes E valuates the combined risk from dietary and residential exposures.

HED anticipates conducting an updated aggregate assessment during registration review for all uses of
diuron.

Cancer Yes A formal request for cancer reclassification sh ould be submitted to the Agency if the registrant would like the Agency to consider a proposed mode of action for
diuron.

Cumulative No Not applicable. Diuron has not been identified as a member of a cumulative group that shares a common mechanism of toxicity.

Tolerances Yes The tolerance expression for diuron ( in 40CFR §180.106[a] and [c]) is not in accord with current guidance, as it does not contain t he appropriate coverage and compliance statements. It should be revised during regist ration review to comply with the Agency ’s guidance on tolerance expressions.

There are no Codex MRLs established for diuron, so there are no harmonization issues with rega rd to
Codex. US tolerances are generally not harmonized with Canadian MRLs, with the exception of asparagus at 7 ppm (mg/kg). Further harmonization with Canadian MRLs may be possible during registration
review.

Incidents Will check for updates For a discussion of reported human incidents for
diuron , see pages 19

- 20 of the Scoping Document and
see document titled Diuron: Tier 1 (Scoping) Review of Human Incidents/Epidemiology

.

Guidance for Commente rs: Additional ecological i nformation r equested for this registration r eview , and of particular interest to EPA, is described below.

• M aximum annual application rates per acre (maximum lb ai/A/year) , maximum number
of applications per season (if applicable) and/or year (if applicable) , and minimum applicat ion intervals on all conventional uses on the labels

.

• Ec ological incidents (non

- target plant damage and avian, fish, reptilian, amphibian and mammalian mortalities) not already reported to the Agency

.

• Water quality m onitoring data (see Appendix for further details)

.17 TIMELINE

EPA has created the following estimated timeline for the completion o f the diuron regist ration
review in Table 5

.

Table 5: Projected Diuron Registration Review Timeline

Activity Estimated Dat e Opening the Docket Open Docket and 60

- day Public Comment Period December 2015

Close Public Comment Period February 2016 Case Development

Issue Final Work Plan May 2016

Issue DCI July

– Sept. 2016

Data Submission July

– Sept. 201 8 Open 6 0

- day Public Comment Period for Draft Risk

Assessments 8 Jan.

– March 202 0

Registration Review Decision Open 60

- day Public Comment Period for Proposed Registration Review Decision Oct.

– Dec. 202 0

Issue Registration Review Decision and Begin Post

Decision Follow

- up 2021

Total (years) 6

NEXT STEPS

After the 6 0

- day public comment period closes, the Agency will review and respond to any comments received in a timely manner and then issue a Final Work Plan for the registration
review of diuron

.

8 The regulations governing Registration Review generally requir e 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, t he Agency plans to provide a 60 calendar day public comment period generally for draft risk a ssessment s.18 Appendix

– Additional Areas Considered in the Diu ron Registration Review

PUBLIC COMMENTS AND FEEDBACK :

Guidance for C ommenters: The areas below highlight topics of special interest to the Agency where your comments, data submissions, or reference to sou rces of additional information c ould
be of particular use.

Trade Irritants:

Through the registration review process, the Agency intends to solicit information on trade irritants and, to the extent feasible, take steps toward facilitating irritant resolution. The Agency
will work to harmonize tole rances and international maximum residue limits (MRL s ) and may modify tolerance levels to do so, when possible

. Growers and other stakeholders are asked to

comment on any trade irritant issues resulting from lack of MRLs or disparities between U.S.
toleran ces and MRLs in key export markets, providing as much specificity as possible regarding
the nature of the concern.

Water Quality:

Diuron is identified as a cause of impairment, as defined under section 303(d) of the Clean Water Act, for eight water bodie s in California, based on information provided at EPA’s website. 9
However, no Total Maximum Daily Loads (TMDL) have been developed for diuron

. 10 More information on impaired water bodies and TMDLs can be found at EPA’s website

. 11 The Agency invites submissio n of water quality data for this pesticide. To the extent possible, data should conform to the quality standards in Appendix A of the OPP Standard Operating Procedure: Inclusion of Impaired Water Body and Other Water Quality Data in OPP’s Registration Review Risk Assessment and Management Process 12 in order to ensure they can be used quantitatively or qualitatively in pesticide risk assessments.

Environmental Justice:

EPA seeks to achieve environmental justice, the fair treatment and meaningful involvement of all people, regardless of race, color, national origin, or income, in the development, implementation, and enforcement of environmental laws, regulations, and poli cies. To help address potential environmental justice issues, the Agency seeks information on any groups or segments of the population who, as a result of their location, cultural practices, or other factors, may have atypi cal, unusually high exposure to d iuron compared to the general population. Please comment if you are aware of any sub

- populations that may have atypical, unusually high exposure compared to the general population.

9 http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=885

10 http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id=885&p_pollutant _group_name=PESTICIDES

11 www.epa.gov/t mdl

12 http://www2.epa.gov/pesticide

- reevaluation/opp

- guidance

- submission

- state

- and

- tribal

- water

- quality

- monitoring

data19 ENDANGERED SPECIES :

A risk assessment that supports a complete endangered species determina tion has not been
conducted for diuron. The ecological risk assessment planned during registration review will
allow t he Agency to determine whether use of diuron has “no effect” or “may affect” federally listed threatened or endangered species (listed species) or their designated critical habitats. When an assessment concludes that a pesticide’s use “may affect” a listed species or its designated critical habitat, the Ag ency will consult with the U.S. Fish and Wildlife Service and/or National Marine Fisheries Service (the Services), as appropriate.

On June 5, 2013 , the Center for Biological Diversity and the Pesticide Action Network North
America filed an amended complai nt in its lawsuit in the United States District Court for the Northern District of California, against the EPA for allegedly failing to undergo consultation
with the United States Fish and Wildlife Service and the National Marine Fisheries Service regardin g the effects o f over 50 pesticides, including diuron , on over 1 00 endangered and threatened species throughout the United States (Center for Biological Diversity, et al. v. EPA, et al., No. C 11

- 00293 (N.D.Cal.)

.

P revious endangered species assessment s w ere conducted for Pacific Salmon and Steelhead in

2003 13 and for the California Red

- legged Frog in 2009 14

.

ENDOCRINE DISRUPTOR SCREENING PROGRAM :

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse
outcomes from exposure to che micals. Collectively, these studies include acute, subchronic and chronic toxicity, including assessments of carcinogenicity, neurotoxicity, developmental, reproductive, an d general or systemic toxicity. These studies include endpoints which may be susceptible to endocrine influence, including effects on endocrine target organ histopathology, organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, reproductive loss

, and sex ratios in offspring. For ecological hazard as sessments, EPA evaluates acute tests and chronic studies that assess growth, developmental and reproductive effects in different taxonomic groups. As pa rt of its most recent registration and reregistration decision s for diuron

, EPA reviewed these data and selected the most sensitive endpoints for relevant risk assessment
scenarios from the existing hazard database. However, as re quired by FFDCA section 408(p),
diuron is subject to the endocrine screening part of the Endocrine Disruptor Screening Program (ED SP).

EPA has developed the EDSP to determine whether certain substances (including pesticide active and other ingredients) may have an effect in humans or wildlife similar to an effect produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator may designate.” The EDSP employs a two

- tiered approach to making the statutorily required

13 USEPA, 2003b. Diuron (035505): Analysis of Risks to Endangered and Threatened Salmon and Steelhead. Environmental Fate and Effects Division, Office of Pesticide Programs, U.S. Environmental Protection Agency. http://www.e pa.gov/oppfead1/endanger/litstatu s/effects/#diuron

14 USEPA, 2009. Diuron (035505): Risks of Diuron Use to Federally Threatened California Red

- legged Frog (Rana aurora draytonii). Environmental Fate and Effects Division, Office of Pesticide Programs, U.S. Env ironmental Protection Agency. h ttp://www.epa.gov/oppfead1/endanger/litstatus/effects/#diuron20 determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a
chemical substance to interact with th e estrogen, androgen, or thyroid (E, A, or T) hormonal
systems. Chemicals that go through Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA
will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 testing is designed to identify any adverse endocrine

- related effects caused by the substance, and
establish a dose

- response relationship between the dose and the E, A, or T effect.

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between October 2009 and February 2010, EPA issued test orders/data call

- ins for the first group of 67 chemicals, which contains 58 pesticide active ingredients and 9 inert in gredients. A second list of chemicals identified for EDSP screening was published on June 14, 2013 15 and includes some pesticides scheduled for registration review and chemicals found in water

. Neither of these lists
should be construed as a list o f known or likely endocrine disruptors.

Diuron is on List 2. List 2 represents the next set of chemicals for which EPA intends to issue
test orders/data call

- ins in the near future. For further information on the status of the EDSP, the policies and procedures, the lists of c hemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our website. 16

HUMAN STUDIES :

Occupationa l and Residentia l

The previous diuron risk assessments relied in part on data from studies in which adult human subjects were intentionally exposed to a pesticide or other chemical. These data, which include studies from the Pesticide Handlers Exposure 1.1 (PHED) Database, Outdoor Residential Exposure Task Force (ORETF) database, Agricultural Handler Exposure Task Force (AHETF) database, are (1) subject to ethics review pursuant to 40 CFR 26, (2) have received that review, and (3) are compliant with a pplicable ethics require ments. For certain studies, the ethics review may have included review by t he Human Studies Review Board. Descriptions of data sources, as well as guidance on their use, can be found at the Agency website 17

. In addition, the new studies that are being perfo rmed by the Antimicrobial Exposure Assessment Task Force (AEATF) are being reviewed by the Human Studies Review Board (HSRB) as th ey are designed and completed. The recommendations made by the HSRB are being implemented to ensure that AEATF study participa nts are fully informed and protected as required by the “Protection of Human Subjects” regulation.

15 See http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

- OPPT

- 2009

- 0477

- 0074 for the final second list of

chemicals.

16 http://www2.epa.gov/endocrine

- disruption

17 Available at: http://www2.epa.gov/pesticide

- science

- and

- assessing

- pesticide

- risks/occupational

- pesticide

- handler

exposure

- data and http ://www2.epa.gov/pesticide

- science

- and

- assessing

- pesticide

- risks/occupational

- pesticide

- post

application

- exposure.