2 I NTRODUCTION

This is the Environm ental Protection Agency’s (EPA or the Agency ) Final Work Plan (FWP) for the registration review of diflubenzuron

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

- HQ

- OPP

- 2012

- 0714 ). Diflubenzuron is an acaricide/insecticide (insect growth regulator) regist ered for use against leaf

- eating insect larvae (e.g., gypsy moths, mosquito larvae, rust mites). It also acts as an ovicide, killing insect eggs. Diflubenzuron does not affect adult insects that have finished molting. It is registered for use in agricul tural (e.g., citrus, cotton, mushroom) and non

- agricultural use sites (e.g., forest, ornamental plants, rangeland).

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.

Informatio n 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 response s to th o se comments

. This section is followed by

diflubenzuron’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

There are no additional updates on diflubenzuron since the PWP.

SUMMARY OF COMMENTS AND AGENCY RESPONSES

During the 60

- day public comment period on the Diflubenzuron Preliminary Work Plan , which opened on September 26, 2012 and closed on November 26, 2012 , the Agency received two public comment s

. One comment was submitted by the diflub enzuron technical registrant Chemtura Corporation (Chemtura) and the other from the FIFRA Endangered Species Task

Force ( FESTF ) . The comments 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 o r information were received on those issues.

This section does not capture every comment made on the PWP nor all of the Agency’s

responses. Summarized below are public comments of a broader regulatory nature. Public

1 http://www.epa.gov/oppsrrd1/registration_review/3 comments and EPA responses in their e ntirety are located in the docket, EPA

- HQ

- OPP

- 2012

- 0714 . Summarized public comments and Agency responses related to the anticipated ecological

risk assessment or data needs are in the Response to Chemtura 60

- day Response to September 26, 2012 Registration Review (PC Code 108201 DP408278)

.

Comments submitted by Chemtura Corporation in EPA

- HQ

- OPP

- 2012

- 0714

- 0010.

1. Comment : In response to Guideline (GLN) requirement 850.1735, freshwater invertebrate whole sediment, Chemtura commented that t wo sediment dwelling insect studies involving diflubenzuron were submitted to EPA (MRIDs 46369301 and 46369302). Chemtura will be providing additional information from the contact laboratory to address EPA comments (DERs for these two studies will be needed to provid e complete response. DERs have been requested from EPA but not received to date).

Response : The data evaluation records (DERs) and associated cover memos were sent to
Chemtura in response to their comment

.

2. Comment: Chemtura provided an updat e on the outstanding Rere gistration Eligibility

Decision (RED) DCI data requirements.

Response : The Agency will continue to work with the registrant to address these outstanding RED data requirements.

Comments submitted by FIFRA Endangered Species Tas k Force in EPA

- HQ

- OPP

- 2012

- 0714

- 0011

.

3. Comment : The FIFRA Endangered Species Task Force (FESTF) submitted a comment that the Agency should ensure any company who is a technical registrant for diflubenzuron, but not a member of the FESTF or a company having met it s 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 regist ration review and makes its registration review decision.

PLANNED DATA NEEDS

The table below summarizes the planned data needs for diflubenzuron based on the Registration Review: Problem Formulation for the Environmental Fate, Ecological Risk, Endangered Species, and Drinking Water Exposure Assessments for Diflubenzuro n and the Diflubenzuron: Human Health Risk Scoping Document in Support of Registration Review. The planned data needs have not changed from what was included in the PWP.4 Planned D ata Needs for Diflubenzuron’s Registration Review

Guideline

Number Study Title Test Material Estimated

Timeframe

(Months from receipt of DCI)

850.1735 Freshwater invertebrate

– whole sediment TGAI 12

Non

- GLN

(Special Study) Pollinator larval toxicity study TGAI 12

Non

- GLN

(Special Study) Residues in pollen and nectar TGAI 36

Non

- GLN

(Special Study) Pollinator chronic feeding study TGAI 12

The studies listed below were previously required through a generic data call

- in ( GDCI

- 108201

- 17757 ),

issued in February 1997 , and are still outstanding 2 . The se studies are listed in this document as background; they will NOT be included in the anticipated R egistration R eview DCI as they are already required through the earlier DCI

.

860.1380 Storage stability Residue of

Concern in review

860.1500 Crop field trials TEP in review

860.1900 Field rotational crops TEP more information

requested

860.1340b Residue analytical methods PAI in review

TGAI = technical grade active ingredient; TEP = typical end

- use product ;

2 See page 6 of the Diflubenzuron: Human Health Risk Scoping Document in Support of Registration Review for details on specific studies in review.5 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 diflubenzuron

. For human health,

EPA will con duct revised residential risk assessment 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 standard operating p rocedures or default exposure assumptions

.

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

Problem Formulation and HED Scoping Document and the planned assessments have not

c hanged from what was included in the PWP

.

Planned Risk Assessments for Diflubenzuron’s 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

Incidents Yes For a discussion of diflubenzuron’s reported ecological incidents, see page 17 of the Problem

Formulation.

Human Health Dietary

Food No Absent any new toxicity, residue chemistry, or exposure data; changes to the standard operating procedures; or default exposure assumptions that could impact the overall risk conclusion, an updated dietary (food and drinking water) assessment is not anticipated to be needed for registration review. Drinking water No

Occupational Handlers (mixers, loaders, applicators) No Absent any new toxicity or exposure data ; changes to the standard operating procedures ; or default exposure assumptions that could impact the overall risk conclusion, an updated occupational assessment is not anticipated to be needed in registration review. Post

- application No

Residential

Handlers Yes

Post

- application Yes

Other Aggregate Yes E valuates the combined risk from dietary and residential exposures.6 Type of Risk Assessment Conduct? Notes

Cumulative No Diflubenzuron is not assumed to have a common mechanism of toxicity with other substances.

Tolerances Yes Tolerance expression needs to be updated

Incidents No For a discussion of diflubenzuron’s reported human incidents, see page 12 of the Scoping Document.

TIMELINE

EPA has created the following estimated timeline for the completion of diflubenzuron’s registration review

. The projected timeline has not changed since the PWP.

Registration Review for Diflubenzuron

– Projected Registration Review Timeline

Activities Estimated Date Opening the D ocket Open Docket and Public Comment Period 2012

– September

Close Public Comment 2012

– November Case Development

Final Work Plan 2013

– February

Issue DCI 2013

– Oct

- Dec.

Data Submission 2016

– Oct

- Dec. Open Public Comment Period for Draft Risk Assessments 2018

– April

- June

Close Public Comment Period 2018

– July

- Sept. Registration Review Decision Open Public Comment Period for Proposed Registration Review

Decision 2018

– Oct

- Dec.

Close Public Comment Period 2019

– Jan

- March Registration Review Decision and Begin Post

- Decision Follow

- up 2019

Total (years) 7

NEXT STEPS

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

effects studies for diflubenzuron through a data call

- in, expected to be issued in 2013

.