Page 1 of 3 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-Verte brate 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 )Page 2 of 3 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. Methox yfenozide is proposed for use by both aerial and ground application, with a pplication 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. Becaus e 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 chroni c and cancer dietary assessments. The last drinking water assessment for methoxyfenozide focused on the chemical’s use on pineapples grown in Hawaii. Drinki ng water concentrations (EDWCs) were estimated using the FIRST model (FQPA I ndex Reservoir Screening Tool) for surface water, the SCI-GROW (Screening Concentr ation 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 th at assessment (USEPA 2013), EDWCs of 251 ppb (highest peak value, applicable to acute dietary assessm ent) and 214 ppb (postbreakthrough average, applicable to chr onic and cancer dietar y assessment) were
recommended for the Health Effects Division’s (HED) dietary risk assessment, as the HED dietary assessment considers all re gistered uses of methoxyfenozide ( Table 1 ). These were the highest EDWCs obtained (o f all registered methoxyfenoz ide 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 pinea pple 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-GWPage 3 of 3 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 th e 0.10 lb ai/A maximum single rate stated in the label.

Reference

USEPA 2013. DP Barcode: D416709. Drinking Wate r Assessment for the IR-4 New Use Petition for the Use of Methoxyfenozide on Pineapple from Environmental Fate and Effects Division (EFED) to Registra tion Division (RD), from Ideliz Negrón Encarnación to Elizabeth Holman December 19, 2013.

Attachment I

121027_416709_DW A_12-19-13