 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

                              WASHINGTON, D.C. 20460

  SEQ CHAPTER \h \r 1 OFFICE OF

PREVENTION, PESTICIDES AND

TOXIC SUBSTANCES

  SEQ CHAPTER \h \r 1 								Chemical Name: Indoxacarb

								PC Code: 	067710

								DP barcode: 	351088

July 9, 2008								

MEMORANDUM

Subject:	Drinking Water Exposure Assessment for IR-4 Petition: 

		Use of Indoxacarb on Garden Beet and Bushberries

To:	Susan Stanton			

Registration Division (7505P)

From:		James Lin, Acting Risk Assessment Process Leader 

		Nancy Andrews, Branch Chief

		Environmental Risk Branch I

Environmental Fate and Effects Division (7507P)

Summary

The estimated surface water drinking water concentrations for DPX-MP062
(Indoxacarb) are:  

25.1 ug /L for the 1 in 10 year annual peak concentration (acute)  

 5.4 ug /L for the 1 in 10 year annual mean concentration (non-cancer
chronic) and  

  2.8 ug /L for the 30 year annual mean concentration (cancer chronic). 
 

The SCI-GROW estimated ground water drinking water concentrations for
DPX-MP062 are not expected to exceed 0.21 μg/L, which was based on 4
applications of 0.11 lb ai/ac per application.

Previous Drinking Water Assessment

EFED has issued a revised drinking water assessment for indoxacarb to
support the Section 3 and Section 18 uses (dated: 02/01/2007, DP# 293793
and 335124).  The resulting drinking water concentration estimations are
based on the cotton use due to its highest total application rate of
0.44 lb ai/ac resulting from 4 applications of 0.11 lb ai/ac.

Proposed Label Information 

This IR-4 petition 8E7324 requests EFED to provide HED with estimated
drinking water concentrations for tolerance purpose.  The label
Indoxacarb DPX-MP062 [Avaunt® (30 WG)] targets for control of beet
armyworm and garden webworm in beet (garden) production; and for control
of cranberry fruitworm, cherry fruitworm and winter moth in bushberry
production.  The use rate information is summarized below:

Crop	Maximum Rate per Acre per Application	Maximum Number of
Applications	Minimum Interval Between Applications	Maximum Rate per Acre
per Season

Beet (Garden)	0.11 lb ai/ac	4	3 days	0.44 lb ai/ac

Bushberry	0.11 lb ai/ac	4	7 days	0.44 lb ai/ac



Conclusion

The new proposed use rate for this IR-4 petition is a little bit less
compared to the cotton use of 0.12 lb ai/ac per application, which has
been assessed previously.  Due to the high rainfall, runoff potential of
the cotton modeling scenario in Mississippi, the proposed IR-4 uses will
not exceed the drinking water estimates based on cotton use, therefore,
the estimated drinking water concentrations will not change with the new
proposed IR-4 uses.  The results presented in the drinking water memo
for DP 293793 and 335124 (dated 02/01/2007) should be used.

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