				

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

OFFICE OF

PREVENTION, PESTICIDES AND

TOXIC SUBSTANCES



March 3, 2008

MEMORANDUM

SUBJECT:	 	 Revised Phorate RED

TO:			Phorate Docket (EPA-HQ-OPP-2008-0174)

FROM:			Steven Bradbury, Ph.D.

			Director, Special Review and Reregistration Division

This memo pertains to the requirement for a 25% application rate
reduction for all uses of phorate to mitigate potential post-application
risks to workers, as outlined in the 2001 phorate Interim Reregistration
Eligibility Decision (IRED).  The phorate IRED became a Reregistration
Eligibility Decision (RED) in July 2006, when the organophosphate
cumulative risk assessment was completed.

Phorate is typically applied at planting and is incorporated into the
soil.  It is persistant in soil, and residues are potentially available
for post-application worker exposure several weeks after application. 
In the 2001 IRED, a quantitative assessment of post-application risks
was not conducted because the Agency lacked sufficient information on
agricultural practices and relevant data on residue transfers from soil.
 Based on the qualitative evaluation of the availability of residues for
post-application exposure, the Agency required a 25% application rate
reduction for all phorate uses, unless efficacy data demonstrated that
the lower rate was ineffective.

Based on preliminary information from the technical registrant
indicating that phorate may not be effective at a 25% reduced rate, and
in light of the fact that the Agency now has improved information about
agricultural practices for many of the crops on the phorate label, the
Agency is currently reevaluating the need for the 25% rate reduction. 
EPA’s Biological and Economic Analysis Division will be reviewing
available data to determine if cultural activities for the labeled crops
involve soil contact.  If so, the Health Effects Division will conduct a
new post-application risk assessment.  

Although phorate is scheduled for registration review in early fiscal
year 2009, the Agency is proceeding immediately with its reevaluation of
post-application worker risk.  Based on the findings of this new
evaluation, the Agency may find it necessary to implement additional
mitigation measures in order to reduce the potential for
post-application worker exposure.  In the interim, all phorate labels
are eligible for reregistration if they contain all label requirements
outlined in the 2001 Phorate IRED, with the exception of the 25% rate
reduction discussed in this memorandum. 

If you have any questions and/or concerns regarding the information
provided herein, please contact the Chemical Review Manager, John W.
Pates, Jr., at 703-308-8195.

		

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