U.S. ENVIRONMENT AL PROTECTION AGENCY 

Washington, D.C. 20460 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

PC Code: 138009 

DP Barcode: 425591, 425593, 425596, and 425599 

Date: September 10, 2015 

MEMORANDUM 

SUBJECT: Fluxapyroxad: Drinking Water Assessment for the Proposed Section 3 New Use 

Registration, Application to Citrus, Grass Forage, Fodder, Straw, and Hay, Grass 

for Seed, and Nongrass Animal Feed, including Alfalfa and Clover 

TO: Driss Benmhend, Risk Manager Reviewer 

Shaja Joyner, Product Manager 

FROM: 

Rachel Holloman, Branch Chief 

Registration Division (7505P) 

Mohsen Sahafeyan, Dietary Assessor 

Donna Davis, Branch Chief 

Risk Assessment Branch VI 

Health Effects Division (7509P) 

Chuck Peck, Environmental Engineer ~ /7 ,//.,.., 2015.09.10 

Environmental Risk Branch IV l_f::£__iL ~ 11 :23:58 -04'00' 

Environmental Fate and Effects Division (7507P) 

REVIEWED Jim Carleton, PhD, Senior Scientist JAMES ~ .. ~~.,,...u 

BY: Environmental Risk Branch IV ~~~~:.:::.::, 

Environmental Fate and Effects Division (7507P) CARLETON =~=~; -oo,. 

APPROVED JeanHolmes, DVM, MPHBranchChief o,/A-~. f/)d/J 

BY: Environmental Risk Branch IV /"' .....--

Environmental Fate and Effects Division (7507P) 

The Environmental Fate and Effects Division (EFED) has reviewed the proposed Section 3 Label 

Amendment for fluxapyroxad (PC Code: 138009) for applications to citrus, grass forage, fodder, 

straw, and hay, grass for seed, and non-grass animal feed, including alfalfa and clover. The new 

uses are being proposed for the following products: Priaxor (Reg. No. 7969-311 ), lmbrex (Reg. 

No. 7969-306), and Sercadis (Reg. No. 7969-309). It should be noted that Priaxor® also contains 

the active ingredient pyraclostrobin, which is not being evaluated in this assessment. A separate 

DW A is being conducted for pyraclostrobin. 

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The proposed rates for the various uses are provided in Table 1. Except for turf, which has a 

maximum annual application rate specified on the label, EFED assumed one growing season per 

year in the development of the maximum annual use rates. Additionally, the current uses for turf 

and rice are provided in Table 1, as these are the uses that have driven previous drinking water 

assessments. 

Ta ble I. Maximum app r 1cation rates fi or fl uxapyroxa d new an d prev1ous1v assesse d uses 

Label Rates 

Crop Max Single Use Rate Max Number of Max Annual Use Rate 

Obs a.iJA) Annlications per season (lbs a.iJA) 

Citrus 0.122 4 0.488 

Grass forage, fodder, 0.089 3 0.267 and hay 

Grass for seed 0.089 3 0.267 

Nongrass animal feed, 

including alfa lfa and 0.089 3 0.267 

clover 

Turf 0.23 4 0.92 

Rice 0.135 2 0.27 

Table 2 depicts the EDWCs that EFED has recommended for use in previous OW As (OP Barcode 

426700, April I 0, 2015). As the application rates for the new uses are equal to or below the 

application rates for the uses that generated the currently recommended EDWCs (turf and rice), 

the EDWCs for the proposed applications are not expected to exceed the currently recommended 

EDWCs and have not been modeled. EFED recommends the use of the groundwater EDWCs for 

turf in HED's drinking water assessment for these new uses. 

T able 2. Recommended estimated drink.in~ water concentrations (EDWCs) for flu xapyroxad new uses 

DRINKING USE (rate modeled) MAXIMUM ESTIMATED 

DRINKING WATER WATER CONCENTRATION (EDWC) SOURCE 

l-in-10 year 1-in-10 year (MODEL USED) acute chronic (μg/L) 

(u!:!IL) 

Surface water Foliar Rice 127 127 (Tier I Rice Model) (0.1 35 lbs a.i./A x 2, RTI = 7 days) 

Groundwater Aerial Foliar 

(PRZM-GW) (turf, 0.23 lbs a.i./A x 4, RTI = 14 203 188 

days) 

Bold values are recommended for use in OW A. 

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