Docket Number EPA-HQ-OPP- OPP-2011-0720 www.regulations.gov



## Butralin Final Work Plan

Registration Review: Initial Docket

Case Number 2075

Approved by:



### Date: 

## November 2012**~~p~~~:n** 

### Richard P. Keigwin, Jr.

Director

Pesticide Re-evaluation Division

/I**/r30/~t:J/r::L_**2

I NTRODUCTION

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

- HQ

- OPP

- 2011

- 0720)

. Butralin is a dinitroaniline plant growth regulator registered for use only o n tobacco to inhibit sucker growth; it has no food, feed, or residential uses. Butralin inhibits microtubule assembly needed for cell division, thereby disrupting rapid plant growth , such as growth of tobacco suckers that would otherwise take energy from leaf formation

.

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 cont inues 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 pra ctices 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 butralin’s registration review planned data needs, risk assessments expected to be conducted , and the projected registration review timeline. Last, there is a discussion of next steps.

UPDATES SINCE THE PWP WAS ISSUED

There are no updates on the butralin registration review case since the PWP was issued in July

2012

.

SUMMARY OF COMMENTS AND AGENCY RESPONSES

EPA published the Butalin Preliminary Work Plan a nd initial registration review docket for a 60

- day public comment period, which opened on Ju ly 6, 2012 . The Federal Register Notice announcing the docket opening 2 erroneously listed the comment period end dat e as August 19, 2012. However, on July 10, 201 2

, EPA extended the comment period until September 10, 2012

to allow for a full 60

- day public comment period . T he Agency received no public comments o n the Butralin Preliminary Work Plan

.

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

2 See 77 FR 40048; FRL

- 9352

- 1.3

PLANNED DATA NEEDS

The following t able summarizes the planned data needs for butralin based on the February 14,

2012 EFED Registration Review Problem Formulation for Butralin 3 and the March 12, 2012 document, Butralin. 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 Data Needs for Butralin Registration Review

Guideline

Number Planned Data Requirements Test

Material Study

Duration
Environmental Fate and Effects

835.1240 Adsorption/Desorption TGAI 12

835.4100 Aerobic Soil Metabolism TGAI 24

835.4300 Aerobic Aquatic Metabolism TGAI 24

835.4400 Anaerobic Aquatic Metabolism TGAI 24

85 0 .6100 1 Environmental Chemistry Methods (ECM) and

Independent Laboratory Validation (ILV) in soil

and water TGAI 12

850.1350 Chronic Estuarine Invertebrate TGAI 12

850.1400 Fish Early Life

- stage (freshwater and saltwater) TGAI 12

850.2100 Avian acute (passerine species) 2 TGAI 12

850.3020 Acute contact toxicity, Honey bee TGAI 12

Non

- guideline Acute oral toxicity, Honey bee 2 TGAI 1 2

Non

- guideline Whole Sediment Chronic Toxicity Invertebrates,

Chirononomus dilutus 2 ,3 TGAI 12

Non

- guideline Whole Sediment Chronic Toxicity Invertebrates,

Hyallella azteca 2 ,3 TGAI 12

Human Health Effects

870.6200 Acute and Sub

- chronic Neurotoxicity TGAI 24

870.7800 Immunotoxicity TGAI 12

Outstanding Data Requirement under GDCI

- 106501

- 17782

850.4150 Vegetative vigor 4 TEP 12

TGAI = technical grade active ingredient; TEP = typical end

- use product

1 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 A vailability” 77 FR 38282, June 27, 2012.
http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

- OPPT

- 2009

- 0154

- 0028

2 The data call

- in ( DCI ) will provide that a study protocol must be submitted for review (within 90 days of receipt of the DCI) and approval by the Agency prior to initiation of the study.

3 Acute sediment toxicity studies were inadvertently listed in the Preliminary Work Plan (PWP) . This was a

typograp hical error. Chronic studies are needed, as indicated on page 4 of the PWP.

4 EPA is currently reviewing a submitted study (MRID 44431002).

3 This document contains a January 5, 2012 Tier I Drinking Water Assess ment for Butralin Supporting Registration

Review Problem Formulation

.4

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 butralin

. For human health, EPA will

conduct a limited assessment to evaluate inhalation exposure and risks to those who smoke from

butralin residues in tobacco

. I f toxicological endpoints or points of departure are revised based

on the data that are required for registration review

, the Agency will consider the need to update

the entire human health assessment.

The table below summarizes the planned registration review risk assessments

, based on the

EFED Problem Formulation and HED Scoping Document

. T he planned assessments have not changed from what was described in the PWP

.

Planned Risk Assessments for Butralin’s Registration Review

Type of Risk Assessment Conduct ?

Yes/No Notes

Ecological and Environmental Fate Comprehensive ecological (species

to be assessed include terrestrial and aquatic organisms ), including endangered species Yes The planned ecological risk assessment will support a complete endangered species determination for

butralin.

Incident Monitoring Yes For a discussion of butralin’s reported ecological incidents, see page 12 of the Problem Formulation.

Human Health Dietary

Food No Butralin is not used on food or feed commodities. Drinking water No EPA does not expect significant dietary exposure to butralin residues in drinking water 4

. Occupational Handlers (mixers, loaders, applicators) No EPA will rely on p revious assessments , which

resulted in risk estimates that were not of concern

Post

- application No

Residential

Handlers No Butralin is not registered for residential use.

Post

- application No Inhalation (smokers) Yes EPA will evaluate potential s hort

- term inhalation exposure and risk for people who smoke tobacco and may be exposed to butralin residues in tobacco. Residential/bystander Yes EPA may evaluate potential off

- target movement of butralin into residential settings.

4 See the Tier I Drinking Water Assessment in the EFED Problem Formulation5

Type of Risk Asses sment Conduct?

Yes/No Notes

Other Aggregate No There is no dietary exposure from food and no significant exposure from drinking water.

Cumulative No EPA has not made a common mechanism of toxicity finding for b utralin and any other substances. Furthermore, butralin does not appear to produce a toxic metabolite produced by other substances.

Tolerances No No established US tolerances or Codex, Canadian, or

Mexican MRLs.

Incidents Yes For a discussion of butralin’s reported human incidents, see page 6 of the Scoping Document.

TIMELINE

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

review

. Although the registration review docket opening was delayed from June 2012 to July

2012 for butralin, th e overall registration review timeline has not changed from the PWP

.

Registration Review Timeline for Butralin

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

– July

Close Public Comment 2012

– September Case Development

Final Work Plan 2012

– November

Issue DCI 2013

– July

– Sept.

Data Submission 2015

– July

– Sept. Open Public Comment Period for Draft Risk Assessments 2017

– Jan.

– March

Close Public Comment Period 2017

– April

– June Registration Review Decision Open Public Comment Period for Proposed Registration Review

D ecision 2017

– July

– Sept.

Close Public C omment P eriod 2017

– Oct.

– Dec. Registration Review D ecision and Begin P ost

- D ecision F ollow

- 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 butralin through a data call

- in, expected to be issued in 2013.