UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

PC Code No.: 080302

DP Barcodes: 414489

Date: May 19, 2014

MEMORANDUM

SUBJECT: Estimated Drinking Water Concentrations of Fluopyram New Uses on Cotton (infurrow and seed treatment), Soybeans (seed treatment) and Peanuts (in-furrow and foliar 

applications) for the Use in Human Health Risk Assessment.

TO: Marcel Howard, Risk Manager Reviewer,

Fungicide Branch, Registration Division (7505P)

AND Christine Olinger, Branch Chief, RAB 3

Health Effects Division (7509P)

FROM: Mohammed A. Ruhman, Ph.D., Senior Agronomist.

Environmental Risk Branch V, 

Environmental Fate and Effects Division (7507P)

THRU: Mah T. Shamim, Ph.D., Chief

Environmental Risk Branch V, 

Environmental Fate and Effects Division (7507P)

I. Summary

This memo presents the Estimated Drinking Water Concentrations (EDWCs) for parent fluopyram

for use in an FQPA human health risk assessment.

It is noted that the registrant is seeking registration of fluopyram, for new uses as a fungicide to 

prevent and/or control fungus diseases on cotton (as a seed treatment and in-furrow application 

during planting), soybeans (as seed treatment only) and Peanuts (in-furrow application during 

planting and as foliar spray). 

EDWCs for current and new uses are summarized in Table 1, below.
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Table 1 A list of the surface/ground water EDWC values for fluopyram.

Surface Water EDWCs (ppb); 1-in--10 Years) ) 1

Ground Water EDWCs (ppb) 2

Acute Non-cancer/Chronic Cancer/Chronic Acute Chronic

19.4 4.90 3.487 87.5 76.8

1 Surface water is based on: acute value from STD MScotton scenario and chronic values from MEpotato scenario. 

2

 Ground water is based on WISANDS_STD GW Scenario noting that the acute/chronic values obtained for ground 

water by SCIGROW modeling did not change from previous assessment (value= 0.319 ppb; not included in the Table)

Based on the results above, the surface water acute 1-in-10 years peak EDWC is 19.4 ppb for 

parent fluopyram while the surface water non-cancer/chronic 1-in-10 years annual mean EDWC is 

4.90 ppb and the 1-in-10-years overall mean cancer/chronic is 3.487 ppb. For ground water the 

acute EDWCs is 87.5 ppb and the chronic 76.8 ppb.

The above stated values should replace earlier estimates as it represent the upper-bound estimates of 

total concentrations that might be found in surface water and ground water due to the current and 

new use of fluopyram as a fungicide. EDWCs for surface water (Table 1) may be considered as 

refined due to the fact that foliar decay rate was used in all PRZM/EXAMS modeling runs. This 

refinement resulted in only slight reduction in the acute values and much significant reduction in the 

non-cancer and cancer EDWCs. Foliar decay rate was calculated from two studies in which the 

residue was determined on and in foliage with no rain or irrigation occurring during the study period.

EDWCs for ground water may be further refined, if needed.

II. Introduction

Previously, the screening level EDWCs from surface water sources were calculated using Tier II 

PRZM (Pesticide Root Zone Model) and EXAMS (Exposure Analysis Modeling System). The 

Tier I SCI-GROW (Screening Concentration in Ground Water) model was used for calculating 

the EDWCs from ground water sources. These previous estimates are presented in the attached 

EDWC Memo (Attachment 1: DP Barcodes: 3533-19, 3638-12/20-22 & 24, and 3697-73 dated 

July 8, 2011).

The new use patterns are summarized in Table 2 based on the proposed new label of Fluopyram ST

(EPA Reg. No. 264-XXX) and the amended label of Luna® Privilege (EPA Reg. No. 264-1078). 
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Table 2 New and amended use patterns for fluopyram

Crop Form 1 Maximum Rates (lbs a.i/A

Minimum

Intervals 

(days)

Application Method(s) and 

Timing

Cotton seed treatment 1 0.066 20.066 Not Applicable Seed Treatment

Cotton 2 0.222 0.222 Not Applicable

In-Furrow application at 

planting; Assume Ground

Cotton total 1 & 2 0.066 + 0.222 0.288 Not Applicable

Assume Ground application 

at time of seeding (Seed + 

Furrow)

Soybean seed treatment 1 0.138 30.138 Not Applicable Seed Treatment

Peanuts 2 0.222 0.445 14

Assume Ground application 

at time of seeding (Furrow) + 

another foliar application 

post- emergence (Ground, 

Air Or Chemigation)

1Form= Formulation: 1= Fluopyram ST: EPA Reg. No. 264-XXX (a.i Fluopyram alone); and 2= Luna® Privilege: EPA 

Reg. No. 264-1078 (a. I Fluopyram alone)

2 Calculations of the cotton seeds application rate/A is based on BEAD maximum seeding rate of 85,000 seeds/A: 

Application Rate= 0.07716 X (85,000/100,000)= 0.065586 lbs a.i /A

3 Calculations of soybean seeds application rate/A is based on BEAD maximum seeding rate of 250,000 seeds/A: 

Application Rate= 0.07716 X (250,000 140,00)= 0.137786 lb a.i /A

In consideration of the new labels and the required use of the new PRZM ground water model 

(PRZM-GW), it was necessary to perform the following:

(1) For surface water EDWCs: execute new PRZM/EXAMS runs to represent the new crops 

of cotton (CAcottonWirrigSTD and MScottonSTD); soybeans (MSsoybeanSTD); and 

peanuts NCpeanutSTD); and

(2) For ground water: execute PRZM-GW runs for all the crops (new and currently registered 

uses)

III. Estimating Drinking Water Exposure from Surface Water Sources

With few exceptions, the exact procedure/parameters used previously in in the attached EDWC 

Memo (Attachment 1: DP Barcodes: 3533-19, 3638-12/20-22 & 24, and 3697-73 dated July 8, 

2011) were used in modeling the proposed new uses. The exceptions include the use of 

appropriate application parameters (Table 2), scenarios, chemical application method (CAM=4

for soil incorporation instead of CAM 2 for foliar application) and seeding depths of 1.27 cm for 

cotton, 1.91 cm for soybeans and 3.81 cm for peanuts. Additionally, no drift was assumed for 

modeling the seed treatment uses.

Tier II PRZM/EXAM results for the new uses are summarized in Table 3, below.
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Table 3 A summary of surface water EDWCs (in ppb) for the proposed new uses of fluopyram

Crop: Scenario Acute (Peak) Non-cancer/Chronic Cancer/Chronic

Cotton: MScotton 19.42 4.614 2.837

Cotton: CAcotton 4.12 1.725 0.785

Soybeans: MSsoybeans 15.33 3.461 1.212

Peanuts: NCpeanuts 6.43 2.327 1.798

In comparison with surface water EDWCs for currently registered crops, the peak value of 19.42 for 

new use on cotton was higher than the FLcucumber value of 12.97 ppb and therefore it replaces the 

peak value assigned previously for fluopyram. Chronic values are lower, therefore these values stay 

the same. 
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IV. Estimating Drinking Water Exposure from Ground Water Sources

As per current EFED policy, ground water exposure was modeled using Tier I PRAZM-GW and 

SCI-GROW models. Parameters used in modeling runs were as follows:

Scenarios and application rates and associated parameters:

PRZM-GW calls for using six standard scenarios representing vulnerable ground waters, namely: 

(1) DELMARVA_STD GW, (2) FLCITRUS_STD GW, (3) FLPOTATO_STD, (4) 

GACOASTAL_STD GW, (5) NCCOASTAL_STD, and (6) WISANDS_STD GW. Table 4

contains a summary of the maximum active rate (lbs a.i/A) for all crop use patterns categorized 

in three application rate categories.

Table 4 Summary of PRZM-GW and SCI-GROW input parameters for fluopyram

Parameter Value* Reference (MRID Number)

All Crops, including new use on 

peanuts and excluding new uses on 

cotton and soybeans: Highest 

Application Rate; Number of 

Applications/Year and Minimum 

intervals between applications 

Two applications of 0.225 lb a.i/A (0.252 kg/h) with 5-day interval

(Current & new labels: the maximum label rate for all crops including new 

uses= 0.45 lbs a.i/A entered in two applications of 0.225 lbs a.i/A)

Cotton: Highest Application Rate for 

seeds+ Furrow) One application of 0.288 lb a.i/A (0.323 kg/h; New label)

Soybean: Highest Application Rate 

for seeds One applications of 0.138 lb a.i/A (0.155 kg/h; New Label)

Aerobic Soil Metabolism t1⁄2 (days)

Median: 295

90th %: 464

Median: of 12 values for SCIGROW run; and

90th %: 90th percentile value for PRZM-GW runs

(MRIDs 473723-07 to 09)

Hydrolysis t1⁄2 (days) Stable MRIDs 473723-03/07

Koc (L Kg-1)

Median: 397

Average: 439

Median: of 5 values for SCIGROW run;

Average: of 5 values for PRZM-GW runs

(MRID 473723-01)

* As per current and proposed new labels for the crops and Guidance for Selecting Input Parameters in Modeling the 

Environmental Fate and Transport of Pesticides.

Due to the fact that application rate is the main driver for expected ground water EDWCs it was 

decided to model all scenarios with the highest application rate and minimum interval to 

represent all current crops, except the new uses for cotton, soybeans and peanuts. Three runs 

were executed separately for these three crops using the scenario that gives the highest EDWCs; 

that was WISANDS_STD GW. Other PRZM-GW input parameters are included in Table 4,

above.
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Results for PRZM-GW modeling are summarized in Table 5.

Table 5 PRZM-GW estimated drinking water concentrations (EDWCs ppb) in ground water 

resulting from current and new uses of fluopyram

Crop

Application 

Date Scenario

Highest 

Daily Value

Post Breakthrough 

Average

Average Simulation 

Breakthrough Time

April 15 WISANDS_STD 87.5 76.8

May 15 WISANDS_STD 86.5 75.8

June 15 WISANDS_STD 85.2 74.0 8,250.152 days

April 15 FLCITRUS_STD 64.3 58.8

May 15 FLCITRUS_STD 63.9 58.2

June 15 FLCITRUS_STD 63.5 57.7 5,134.006 days

April 15 NCCOASTAL_STD 63.1 59.0

May 15 NCCOASTAL_STD 63.5 59.3

June 15 NCCOASTAL_STD 64.4 60.0 6,014.616 days

April 15 DELMARVA_STD 57.3 50.0

May 15 DELMARVA_STD 56.1 49.0

June 15 DELMARVA_STD 56.0 48.4 6,241.621 days

April 15 GACOASTAL_STD 20.4 17.2

May 15 GACOASTAL_STD 20.8 17.5

June 15 GACOASTAL_STD 20.8 17.4 8,491.507 days

April 15 FLPOTATO_STD 3.73 3.61

May 15 FLPOTATO_STD 3.68 3.56

All 

Currently 

Registered 

Crops June 15 FLPOTATO_STD 3.66 3.55 10,182.630 days

Peanuts

(new use) May 01 WISANDS_STD 86.4 75.8

Soybeans

(new Use April 15 WISANDS_STD 26.9 23.6

Cotton

(new use) April 15 WISANDS_STD 56.0 49.1 8,250.152 days

Data in Table 5 indicated that the highest acute ground water EDWC is 87.5 ppb of parent 

fluopyram and the chronic value is 76.8 ppb of parent fluopyram. These values are much higher 

than the SCIGROW derived acute/chronic value of 0.319 ppb. Therefore these new values should 

be replaced by the PRZM-GW values.