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OFFICE OF 

CHEMICAL SAFETY AND

POLLUTION PREVENTION

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON D.C., 20460 

 

 

 PC Code: 121027 

 DP Barcode: D422209 

MEMORANDUM 

December 9, 2014 

SUBJECT: Drinking Water Assessment for the IR-4 New Use Petition for the Use of 

Methoxyfenozide on Chives, Herb Subgroup 19A, Green Onion Subgroup 

3-07B and Crop Group Conversions for Stone Fruit Group 12-12 (except 

plum) and Tree Nut Group 14-12. 

TO: Carlyn Petrella, Risk Manager

Richard Gebken, Product Manager 

Invertebrate-Vertebrate Branch II 

Registration Division (7505P) 

 

Andrew Ertman, Risk Manager 

Barbara Madden, Minor Use Team Leader 

Minor Use and Emergency Response Branch 

Registration Division (7505P) 

 

CC: Elizabeth Holman, Dietary and Risk Assessor 

 William Drew, Chemist 

 Risk Assessment Branch II 

 Health Effects Division, (7509P) 

FROM: Karen Milians, Ph.D., Chemist 

 Risk Assessment Branch V 

 Health Effects Division (7509P) 

APPROVED 

BY: Jean Holmes, Branch Chief 

 Environmental Risk Branch IV 

 Environmental Fate and Effects Division (7507P) 
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1. EXECUTIVE SUMMARY 

 EFED has reviewed the IR-4 request for methoxyfenozide registration as a 

insecticide on chives, herb subgroup 19A (except chives fresh leaves), green onion 

subgroup 3-07B (except chives) and crop group conversions for stone fruit group 12-12 

(except plum) and tree nut group 14-12. Methoxyfenozide is proposed for use by both aerial 

and ground application, with application rates that ranges from 0.06 to 0.25 lbs a.i./A 

(depending on the specific pest) and a ten day minimum re-application interval, for a 

maximum total application rate of 1.0 lbs a.i./A/year. Because the new uses are proposed 

at the same maximum application rates than those for previously-assessed uses, EFED 

refers to the last assessment, dated December 19, 2013 (USEPA 2013; DP416709; See 

Attachment I). The recommended estimated drinking water concentrations (EDWCs) for 

the Health Effects Division’s (HED) dietary assessment is 251 ppb for the acute dietary 

assessment and 214 ppb for the chronic and cancer dietary assessments. 

 The last drinking water assessment for methoxyfenozide focused on the chemical’s 

use on pineapples grown in Hawaii. Drinking water concentrations (EDWCs) were 

estimated using the FIRST model (FQPA Index Reservoir Screening Tool) for surface 

water, the SCI-GROW (Screening Concentration In GROund Water (SCI-GROW v2.3, 

Jul. 29, 2003) and PRZM-GW (Pesticide Root Zone Model for Groundwater, version 1.0, 

August 31, 2012) models for groundwater. In that assessment (USEPA 2013), EDWCs of 

251 ppb (highest peak value, applicable to acute dietary assessment) and 214 ppb (postbreakthrough average, applicable to chronic and cancer dietary assessment) were 

recommended for the Health Effects Division’s (HED) dietary risk assessment, as the HED 

dietary assessment considers all registered uses of methoxyfenozide (Table 1). These were 

the highest EDWCs obtained (of all registered methoxyfenozide uses) and were based on 

the fruiting vegetable use represented by the WI corn scenario in PRZM-GW. The EDWCs 

for the pineapple use were lower than the EDWCs from the fruiting vegetable use mainly 

due to lower application rate of the pineapple use (0.44 lb a.i./A/year) compared to the 

fruiting vegetable use (1.0 lb a.i./A/year). 

Table 1. Tier I estimated drinking water concentrations (EDWCs) resulting from 

applications of methoxyfenozide 

FIRST 

Drinking water 

source 

Use (modeled rate)1 Peak Day 

Concentration (ppb) 

Annual Average 

Concentration (ppb) 

Surface water 

(aerial 

application) 

Pineapple 

(0.11 lb a.i./A x 4 applic.; total 

of 0.44 lb ai/A/yr) 

23.5 7.57 

SCIGROW 

Drinking water 

source Use (modeled rate) Screening concentration (ppb) 

Groundwater 

Pineapple 

(0.11 lb a.i./A x 4 applic.; 

total of 0.44 lb ai/A/yr) 

1.76 

PRZM-GW 
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Table 1. Tier I estimated drinking water concentrations (EDWCs) resulting from 

applications of methoxyfenozide 

Crop/Scenario Use (modeled rate)1 Highest Daily 

value (ppb) 

Post Breakthrough 

Average (ppb) 

Average Simulation 

Breakthrough Time 

(days) 

Pineapple / WI 

corn 

0.11 lb a.i./A x 4 applic.; 

Total of 0.44 lb ai/A/yr 

108 93.1 8685 

Fruiting 

Vegetables /WI 

corn 

0.25 lb a.i./A x 4 applic.; 

Total of 1.0 lb ai/A/yr 

251 214 8685 

Value in bold show the EDWCs recommended for HED’s acute (251 ppb), and chronic and cancer (214 ppb) dietary risk assessments, 

as they are considered protective of all the registered uses of methoxyfenozide. 1

To account for a maximum yearly total rate of 0.44 lb ai/A the single rate modeled for pineapple was 0.11 lb ai/A instead of the 0.10 

lb ai/A maximum single rate stated in the label. 

Reference 

USEPA 2013. DP Barcode: D416709. Drinking Water Assessment for the IR-4 New Use 

Petition for the Use of Methoxyfenozide on Pineapple from Environmental Fate 

and Effects Division (EFED) to Registration Division (RD), from Ideliz Negrón 

Encarnación to Elizabeth Holman December 19, 2013. 

Attachment I 

121027_416709_DW

A_12-19-13