Hexythiazox Final Work Plan

Registration Review 

July 2007

Approved by: _____________________                      

Pete Caulkins, Ph.D., Acting Director

Special Review and Reregistration Division

Date: July 2, 2007Introduction:

This is EPA’s Final Work Plan for the registration review of
hexythiazox.  The work plan includes the expected registration review
time line.  The work plan also addresses public comments received
concerning the Preliminary Work Plan in the Summary Document which was
posted in the hexythiazox registration review docket, or any other
comments concerning initial docket postings.  The Summary Document
provided information on what EPA knows about the pesticide and what
additional risk analyses and data or information the Agency believes are
needed to make a registration review decision.  

The Agency is implementing the new Registration Review program and plans
to review each registered pesticide every 15 years to determine whether
it continues to meet the Federal Insecticide, Fungicide, and Rodenticide
Act (FIFRA) standard for registration.  Changes in science, public
policy, and pesticide use practices will 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 that statutory standard.  The
public phase of registration review begins when the initial docket is
opened for each case.  Information on this program is provided at:  
HYPERLINK "http://www.epa.gov/oppsrrd1/registration_review/_" 
http://www.epa.gov/oppsrrd1/registration_review/ . 

Comments Received on Preliminary Work Plan:

EPA received comments during the public comment period on the initial
docket.  However, these comments, which are addressed in this document,
did not change the work plan or timeline described in the Preliminary
Work Plan.  Further, this document makes final the work plan for the
hexythiazox registration review process. 

Risk Assessment and Data Needs:

The Agency will conduct a comprehensive ecological risk assessment,
including an endangered species assessment for all uses.  Additional
ecological data will be needed for this registration review.  However,
the Agency does not anticipate that any additional human health risk
assessments or related data will be needed.

Ecological Risk:

Although ecological risk assessments for most hexythiazox uses were
completed in 2005, the Agency has not conducted a risk assessment which
supports a complete endangered species determination.  The planned
ecological risk assessment will allow the Agency to determine whether
hexythiazox use has "no effect" or "may affect" federally listed
threatened or endangered species (listed species) or their designated
critical habitat.  If the assessment indicates that hexythiazox "may
affect" a listed species or its designated critical habitat, the
assessment will be refined.  The refined assessment will allow the
Agency to determine whether use of hexythiazox is “likely to adversely
affect” the species or critical habitat or "not likely to adversely
affect" the species or critical habitat.  When an assessment concludes
that a pesticide's use "may affect" a listed species or its designated
critical habitat, the Agency will consult with the U.S. Fish and
Wildlife Service and National Marine Fisheries Service (the Services),
as appropriate.  Please refer to Section III (Ecological Risk Assessment
Problem Formulation) of the Hexythiazox Registration Review Summary
Document for a detailed discussion of the anticipated risk assessment
needs.

The Agency needs the following data in order to conduct a complete
ecological risk assessment, including an endangered species assessment
for all uses:

Estuarine/Marine Invertebrate, Acute (72-3c)

Estuarine/Marine Invertebrate Life-cycle (72-4b)

Human Health Risk:

The Agency believes that previously completed dietary assessments are
adequate and that there is no dietary risk that exceeds the Agency’s
level of concern (LOC); thus, no additional data are needed.  Please
refer to Section IV (Human Health Effects Scoping Document) of the
Hexythiazox Registration Review Summary Document, for a detailed
discussion of the human health risk assessments. 

Timeline:

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

Activities 	Estimated Month/Year or Calendar Year Quarter/Year

Phase 1: Opening the docket

Open Public Comment Period for Hexythiazox Docket  	February 2007

Close Public Comment Period 	May 2007

Phase 2:  Case Development

Develop Final Work Plan (FWP)	July 2007

Issue DCI 	2nd Qtr. 2008

Data Submission	2nd Qtr. 2010

Open Public Comment Period for Preliminary Risk Assessments 	3rd Qtr.
2011

Close Public Comment Period	4th Qtr. 2011

Phase 3: Registration Review Decision

Open Public Comment Period for Proposed Reg. Review Decision 	1st Qtr.
2012

Close Public Comment Period 	2ndQtr. 2012

Final Decision and Begin Post-Decision Follow-up	2012

Total (years)	5



Summary of Comments Received During Docket Opening: 

The hexythiazox registration review docket was open for a 90-day comment
period beginning on February 2, 2007.  During that time, three comments
were received.  They are summarized below.

An anonymous commentor indicated approval for the “docket and the
changes proposed.”

A representative for the US Hop Industry Plant Protection Committee
explained that hexythiazox is an important pest management tool for the
hops industry for controlling the two-spotted spider mite. 

The FIFRA Endangered Species Task Force (FESTF) submitted a comment
requesting that any technical registrant for hexythiazox who is not a
member of the FESTF (or a company having met its data compensation
obligations) be asked to provide a formal offer-to-pay to FESTF for
reliance on their data.  In their comment, FESTF also noted that Gowan
is the only technical registrant for hexythiaxox, and Gowan is already
entitled to rely on FESTF data.  

Due to the nature of these comments, a direct response from the Agency
was not prepared. The Agency will consider this information as it
conducts its registration review and makes its registration review
decision.

Next Steps:

A DCI will be developed regarding the data gaps listed under the “Risk
Assessment and Data Needs” section.  Also, a comprehensive ecological
assessment, including an endangered species assessment, will be
conducted for all uses.

 PAGE   26 

Docket Number: EPA-HQ-OPP-2006-0114

www.regulations.gov

Docket Number: EPA-HQ-OPP-2006-0114

www.regulations.gov

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