### EXECUTIVE SUMMARY

T his Tier I Drinking W ater A ssessment to support the Health Effects Division ’s (HED ’s ) Registration Review Assessment for flufenacet is being provided at this time with the following updates and revisions from previous assessments: 1.) To correct an error identified with the maximum application rates evaluated from the most recent drinking water assessm ent addressing estimated upper

- bound surface water concentrations (DP Barcodes Nos. 318616 and 318629, dated October 4, 2006), 2.) To provide and discuss updated monitoring data that is available for

flufenacet and its degradates , and 3 .) To provide an ev aluation for upper

- bound ground water

exposure that is consistent with current EFED policies and modeling tools.

Based on consultation with the Health Effects Division, flufenacet and its thiadone degrade are

the main residues of concern that are consider ed in this drinking water assessment. The u pdated

u pper

- bound EWDCs in surface water and ground water associated with flufenacet uses are summarized in Table 1 . The results in T able 1 show that the driving exposure pathway for drinking water is found fro m flufenacet transport to surface water on an acute basis and ground

water on a chronic basis

. The results demonstrate flufenacet’s ability to move to both surface water and ground water sources. Furthermore, recent monitoring data (spanning from 2001 t o 2013) shows several detections of flufenacet in surface water and ground water wells mainly at

low

- levels within the flufenacet’s main use area in the Midwest. However, there was one

detection of flufenacet at a relatively high level ( 75 ppb ) in a finis hed surface water sample in

India na in 2007. These detections in monitoring data further support the potential for flufenacet exposure in both surface water and ground water.

Table 1. Summary of maximum upper

- bound EDWCs (including flufenacet and

flufen acet thiadone) for surface water and ground w ater associated with the existing uses

of flufenacet.

Surface Water

Acute Chronic Cancer

29 .87 1 

### 9.07 1 

### 5.21 1



### Ground Water

Acute Chronic and Cancer

12.47 2 

### 11.02 2

1. Based on SWCC IL Corn crop scenario

2. Based on PRZM

- GW WI Sands scenario.



### USE CHARACTERIZATION

Flufenacet is currently registered on 13 products 1 

### and used on a variety of agricultural crops including corn for silage, sweet corn, field corn, grass seed, soybeans, triticale, and wheat.

1 Flufenacet products compose of between 24 percent

– 60 percent a.i. Flufenacet is co

- formulated in four of these products comprising of the following compositions: 13.6%:54.4% Metribuzin:Flufenacet, 36%:24% Metribuzen:Flufenazet, 10%:48% Isoxaflutole:Flufenazet, 4.29%:35.71% Isoxaflutole:Fluefenacet.



### 2

### Furthermore, t here are flufenacet forestry uses including Douglas fir, Fras er fir, Grand fir, and

Noble fir trees. Flufenacet is o nly used as a pre

- emergent herbicide and is applied as a broadcast surface spray, banded surface spray, or soil incorporated

. Maximum sing le and s easonal application rates of flufenacet of between 0 .3448

– 0. 8019 lbs. a.i./A are specified on the proposed product labels ( Table 2 )

. Flufenacet usage is mainly confined to the corn and soybean belt of the Midwest, North Carolina, Southern High P lains, and Oregon

.

Table 2

. Summary of u se information for flufenacet

.

USE MAX.

SINGLE

APP.

RATE (lbs. a.i./A) MAX. NUMBER OF

AP PS. and MIN.

RETREATMENT

INTERVAL SEASONAL

APP. RATE (lbs. a.i./A) APP LICATION METHO D AND FORM 1



### Corn (Sweet and Field)

0. 8019 NS 0.8019 Broadcast Surface Spray (Ground)

Banded Surface Spray (Ground)

Soil Incorporated (1

– 2 inches)

(DG, EC, FC, SC)

Soybean 0.4644 NS 0.4644 Broadcast Surface Spray (Ground)

Banded Surface Spray (Ground)

Soil Incorporated (1

– 2

inc hes)

( DG, FC )

Wheat

Triticale 0.3448 NS 0.3448 Broadcast Surface Spray (Ground)

(DG, FC)

3

### Table 2

. Summary of u se information for flufenacet

.

USE MAX.

SINGLE

APP.

RATE (lbs. a.i./A) MAX. NUMBER OF

AP PS. and MIN.

RETREATMENT

INTERVAL SEASONAL

APP. RATE (lbs. a.i./A) APP LICATION METHO D AND FORM 1



### Grass Seed 0.4420 1 0.4420 Broadcast Surface Spray (Ground)

Banded Surface Spray (Ground)

Soil Incorporated (1

– 2 inches)

(DG, FC)

Forestry (Douglas

Fir, Fras er Fir, Grand Fir, Noble Fir) 0.6800 1 0.6800 Broadcast Surface Spray (Aerial and Ground)

Banded Surface Spray

(Aerial and Ground)

Soil Incorporated

(1

– 2 inches)

( DG )

1 Substance form identifiers: DG = Dispersible Granule, EC = Emulsifiable Concent rate, SC = Soluble
Concentrate,

FC = Flowable Concentrate



### EXPOSURE ANALYSIS

• Surface Water

Estimated drinking water concentrations ( EDWCs ) in surface waters for the labeled flufenacet applications are estimated using The Surface Water Concentration Calculator interface (SWCC version 1.092, dated March 6, 2014). Combined exposures from p arent flufenacet and its thiadone deg radate are presented using the F ormatio n

- D ecline method accounting for the presence of both compounds simultaneously in the envi ronment over time. The SWCC is

available on

- line at: http://www.epa.gov/oppefed1/models/water/#swcc

.

Percent crop areas (PCAs) are accounted for in EDWCs specific to each crop to facto r in the portion of watersheds that are typically subject to pesticide loadings and subsequent transport to water bodies. The guidance, “Development and Use of Percent Cropped Area and Percent Turf Area Adjustment Factors in Drinking Water Exposure Assess ments : 2012 Update ”, are used to

4

### determine PCA values for each crop (EPA, 2012). In this assessment, it is anticipated that

flufenacet treatments to corn, soybeans, wheat triticale , and grass seed can all occur in the same watershed, but forestry applicat ions of flufenacet are expected to occur in a separate watershed. Therefore, the maximum EDWCs are shown for each of these distinct groupings considering the anticipated percent coverages of watersheds potentially treated (e.g., percent crop area or PCA)

. C rop scenarios for the crops and forestry uses presented in this assessment represent the highest

and most vulnerable exposure expected for flufenacet considering its potential loading for a certain use (e.g., maximum seasonal application rate) and sites possessing most vulnerable runoff considering the extent of flufenacet’s use in the Midwestern Corn Belt, Southern Plains, North Carolina, and Oregon. Broadcast surface applications to bare ground are evaluated since this is the conservative application scenario for runoff. The fate parameter s and use

- specific input

parameter s for the SWCC surface water modeling are shown in Table 3

. The EDWCs of flufenacet and its thiadone degradate in su rface water are shown for aerial and ground applications in Table 4

. The SWCC output files are provided in Appendix B

.

Table 3

. SWCC input parameter values used for surface water aqua tic exposure estimation with flufenacet and its thidadone degradate

. SWCC Input Parameter Input Value and Unit (Flufenacet/Thiadone

D egradate) Source

Physical Chemical Properties Molecular Weight (g/mol) 363/170 MRID 43441102 and 43850001 

### Vapor Pressure (torr) 2. 40 x 10

- 1 1 

### /1.5x10

- 2 MRID 43441102 and 43850001 

### Solubility in Water (mg/L) 56/200,000 MRID 43441102 and 43850001



### Soil

- Wa ter Partition Coefficient (K
oc 

### ) (mL/g) 434.4/43.5 Average values

MRID 43441137 and 43441140



### Environmental Fate Properties Hydrolysis at pH7 (t 1/2 

### ) Stable /Stable MRID 43441134 and 45796107



### Aerobic soil metabolism (t 1/2 

### )

, Reference Temperature , and

D egradate Molar Formation Fraction 48.2 days at 25 ° C / 2.77 days at 25 ° C

Deg. Molar Formation

Frac.:1.0 MRID 43441141, 43441135, 43850058, & 48604493

Upper 90 TH percentile confidence

interval 1



### Aerobic aquatic metabolism (t 1/2 

### )

, Reference Temperature , an d Degradate Molar Formation Fraction 77.1 days at 25 ° C /160 days at

25 ° C

Deg. Molar Formation

Frac.:1.0 MRID 45796112, 44580203, &

45796111

Upper 90 TH percentile confidence

interval 1



### A na erobic aquatic metabolism (t 1/2 

### ) and Reference Temperature 492 da ys at 25 ° C /303 days at
25 ° C MRID 43850060, 43850061, &

45796110



### 5

### Table 3

. SWCC input parameter values used for surface water aqua tic exposure estimation with flufenacet and its thidadone degradate

. SWCC Input Parameter Input Value and Unit (Flufenacet/Thiadone

D egradate) Source

Deg. Molar Formation

Frac.:1.0 Upper 90 th percentile confidence

interval 1



### Aqueous Photolysis (t 1/2 

### ) and

Reference latitude Stable at 45 ° N /S table at 45 ° N MRID 4 3850056 and 46997401



### Ap plication Methods and Crop Management Input Parameters Crop Scenario and Weather IL Corn

14842 .dvf ( Peoria, IL )

OR Xmas Tree

24232 .dvf ( Salem, OR ) C rop scenarios presented consider a combination of maximum loading and

vulnerable runoff site for flufe nacet’s

use confined to the Midwestern Corn Belt, Southern Plains, Oregon, and North Carolina. Forestry use scenario shown separately considering these uses are anticipated to be in unique

watersheds. 

### Application Rate IL Corn

0.898 kg/ha

OR Xmas Tree

0 .7616 kg/ha Maximum single application rate specified on p roduct l abels



### Number of Applications and

Retreatment Interval IL Corn , OR XmasTree 1 application Based on maximum seasonal app. rates (specified in Table 2 ) and

minimum retreatment intervals

s pecified in product labels. 

### Application Date IL Corn , OR XmasTree 15 day before crop emergence Product labels



### PCA IL Corn

0.95

OR Xmas Tree

1.0 Maximum national PCA for all agricultural and turf use combinations from Table 5 of, “Development and

Use of Percent Cropped Area and Percent Turf Are Adjustment Factors in Drinking Water Exposure Assessments: 2012 Update” 

### Application Methods IL Corn Ground ( Bare Surface )

OR Xmas Tree Ground ( Bare Surface ) P roduct labels



### Application Efficiency IL Corn

Gro und apps.: 0.99 EFED input parameter g uidance for aerial and ground applications



### 6

### Table 3

. SWCC input parameter values used for surface water aqua tic exposure estimation with flufenacet and its thidadone degradate

. SWCC Input Parameter Input Value and Unit (Flufenacet/Thiadone

D egradate) Source

OR Xmas Tree Aerial apps.: 0.95 Spray Drift Fraction IL Corn

Ground apps.: 0.066

OR Xmas Tree

Aerial apps.: 0.135 Spray drift fraction for aerial and ground applic ations from Table 2 of EPA, 2013, “Guidance on Modeling Offsite Deposition of Pesticides via Spray Drift”.

1 The upper 90 th percentile half life calculated as follows: t 1/2 input = tt 1 / 2 � � � � � + (t 90, n

- 1 x σ )

n 1/2

where tt 1 / 2 � � � � � is the mean of the set of half lives from each study, t 90, n

- 1 is the one

- sided t value for the 90 th percentile

level, σ is the standard deviation of the set of half lives determined from each study, and n is t he sample size of the set of half lives determined from each study.



### Table 4

. SWCC estimated upper bound concentrations in surface water ( flufenacet

- equivalent ppb)

.

C rop Scenarios and App. Method 1 

### PCA Annual

Peak (Acute) 1 

### Annual

Mean (Chronic) 1 

### 30

- year Mean (Cancer)

Flufenacet

IL Corn 0.95 26.32 6.76 3.91

OR Xmas Tree 1.0 13.40 5.62 3.26 Thiadone Degradate

IL Corn 0.95 3.55 2.31 1.30

OR Xmas Tree 1.0 2.71 2.35 1.62

Total

IL Corn 0.95 29.87 9.07 5.21

OR Xmas Tree 1.0 16.11 7.97 4.88

*Bold text indicate maximum values.

1 One

- in

- ten year estimated value.



### • G round Water

Ground water estimated concentrations resulting from the existing uses of flufenacet are estimated using the PRZM

- GW (version 1.0 7

, March 6, 2014 ) will be used to evaluate grou nd water exposure. PRZM

- GW is publically available on

- line at http://www.epa.gov/oppefed1/models/water/#przm_gw . Results from the long

- standing tier I

SCI

- GROW model (Screening Concentr ation in GRound Water model, Version 2.3, May 16,

7

### 2006) will also be shown in comparison with the PRZM

- GW modeling results according to EFED guidance related to the evaluation period for the recent release of PRZM

- GW. SCI

GROW is publically available on

- l ine at http://www.epa.gov/oppefed1/models/water/#scigrow

.

Tables 5 and 6 show the input parameter values used in PRZM

- GW and its predicted

concentrations of flufenacet and the thiadone degradate in ground water

. The residue summation approach was used to calculate thiadone concentrations considering its maximum formation fraction in soil from the aerobic soil metabolism study (3.9 percent of applied, MRID No. 43441135) and degradate fr om parent ratio of molecular weights

. Tier I scenarios are run in this

assessment to capture upper

- bound screening exposure based on vulnerable environmental

conditions. Incorporated applications to 2 inches below ground are evaluated as this is the

c ons ervative application method leading to ground water exposure

. The PRZM

- GW output files for both scenarios are provided in App endix C

.

Table 5 . PRZM

- GW input parameter values for physical chemical and fate properties for flufenacet and its thidadone degr adate ground water exposure estimation.

PRZM/EXAMS Input

Parameter Input Value and Unit Source

Pesticide Properties Hydrolysis at pH7 (t 1/2 

### ) Stable /Stable MRID 43441134 and 45796107



### Surface soil metabolism (t 1/2 

### ) at 25 ° C 48.2 days /2.77 days MRID 434411 41, 43441135, 43850058, & 48604493

Upper 90 TH percentile

confidence interval 1



### Soil

- Water Partition Coefficient (K
oc 

### ) (mL/g) 434.4/43.5 Average values

MRID 43441137 and 43441140



### Application Methods and Crop Management Input Parameters Crop Scenar ios and Weather WI Sands: w14920 (La Crosse, WI) NC Coastal: w13722 (Raleigh, NC) GA Coastal: w93805 (Tallahasse, FL)

Delmarva Peninsula: w13781 (Wilmington, DE)

FL Citrus: w12842 (Tampa, FL) FL Potato: w13889 (Jacksonville, FL) Application Date 15 days before crop

emergence Product label



### Application Rate 0 .864 kg/ha /0.02kg/ha 2 Maximum single /seasonal application rate out of all uses proposed for orname n tals on product labels 3 

### Number of Applications and

Retreatment Interval 1 application

Appli cation Methods Incorporated at 2 inches below ground expected to result in the most

conservative EDWCs



### 81 The upper 90 th percentile half life calculated as follows: t 1/2 input = tt 1 / 2 � � � � � + (t 90, n

- 1 x σ )

n 1/2

where tt 1 / 2 � � � � � is the mean of the set of half lives from each study, t 90, n

- 1 is the one

- sided t value for the 90 th percentile

level, σ is the standard deviation of the set of half lives determined from each study, and n is t he sample size of the set of half lives determined from each study.

2 Thiadone equivalent application rate calculated with residue summation method based on its maximum formation

fraction in soil from the aerobic soil metabolism study (MRID No. 43441135 ) and degradate from parent ratio of molecular weights ( Thiadone equivalent App. Rate = 0.898 kg/ha x 363.6 g

- mol

- 1 /170g

- mol

- 1 x 0.039 = 0.02 kg/ha )

. According to the residue summation method, the flufenacet portion of the application rate is calculated as follows (Flufenacet App. Rate = 0.898 kg/ha

– (0.898 kg/ha x 0.039) = 0.864 kg/ha.



### Table 6

. PRZM

- GW estimated upper bound concentrations in ground water (flufenacet

- equivalent ppb)

Tier I Scenario Highest Daily Value ( Acute ) Post

- Breakthrough Average ( Chronic and Cancer)

Flufenacet

WI Sands 12.4 0 11 .0 0

NC Coastal 1.19 1.00

GA Coastal 0.62 0.60

FL Citrus 7.17 6.85

FL Potato <0.01 <0.01

Delmarva Peninsula 2.78 2.22 Thiadone Degradate

WI Sands 0.06 0.02

NC Coastal <0.01 <0.01

GA Coastal <0.01 <0.01

FL Citrus 0.02 <0.01

FL Potato <0.01 <0.01

Delmarva Peninsula 0.07 0.02

Total

WI Sands 12.4 7 11.02

NC Coastal 1.19 1.00

GA Coast 0.62 0.60

FL Citrus 7.19 6.85

FL Potato <0.01 <0.01

Delmarva Peninsula 2.85 2.24

* Bolded values show the high est ground water EDWC.



### The SCI

- GROW model (Screening Concentration in GRound Water model, Version 2.3, May 16, 2006) are also shown in comparison with the PRZM

- GW modeling results according to

current EFED guidance related to the evaluation period for the recent release of PRZM

- GW.

Table s 7 and 8 show the input parameter values used in SCI

- GROW and its predicted

concentrations of flufenacet and the thiadone degradate in ground water , respectively

. The

9

### ground water concentrations generated by SCI

- GROW can be considered suitable for both acute
and chronic exposures

. The SCI

- GROW output files for both scenarios are provided in Appendix C

. The EDWCs from PRZM

- GW are higher and as such are used as the basis for ground water exposure concentrations in this as sessment.

Table 7

. SCI

- GROW input parameter values for physical chemical and fate properties used for flufenacet and thiadone degr a date

. SCI

- GROW Input Parameter Input Value and Unit Source Application Methods and Crop Management Input Parameters

Ma ximum Application Rate (lbs. a.i./A) 0. 8 02 Product Labels



### Number of Applications 1 Product labels 

### Physical Chemical Properties

Soil

- Water Partition Coefficient (K
oc 

### ) 43.5 mL/g Thiadone degra ’s lower mean

K
oc more conservative.

MRID 43441137 and 434411 40 

### Environmental Fate Properties Aerobic soil metabolism (t 1/2 

### ) 48.2 days Total half

- life between

flufenacet and thiadone degradate.

MRID 43441141, 43441135, 43850058, & 48604493



### Table 8

. SCI

- GROW estimated upper bo und concentrations for

flufenac et and its thiadone degradate in ground water ( flufenacet

equivalent ppb).

Acute Chronic and Cancer

0.93

WATER MONITORING DATA

There are some water monitoring data available for flufenacet and its degradates in surface water, stream water, and ground water from the USGS National Water Quality Assessment (NAWQA) and EPA’s Storage and Retrieval Warehouse (STORET) monitoring datasets . In general, the se monitoring data indicate that the SWCC and PRZM

- GW modeling provide reasonably protective estimates of drinking water exposure. In addition, there are additional monitoring data in untreated drinking water, finished drinking water, as well ground water in the EPA Pesticide Database Program (PDP). With all of these data, it should be note d that there are no indications whether or not these data represent targeted sampling observations. However,

10

### there is also a targeted Prospective Ground Water Study submitted by the registrant for flufenacet and its degradates available as well (MRID No. 46997402).

The N AWQA monitoring dataset encompasses 1,845 samples of parent flufenacet at various surface water and ground water monitoring sites for the period between 2001 and 2012.

Flufenacet degradates are not known to have been sampled. The nature of detections of

f lufenacet in the NAWQA data are summarized below:

• Flufenacet was detected in stream water 14 times at various sites in Iowa, Nebraska, Ohio, Maryland, and South Carolina. C oncentrations of up to 0.31 ppb were detected in Dodge County

, Iowa.

• Flufenacet w as detected in wells 3 times at various sites in Iowa and Minnesota. Concentrations of up to 0.04 ppb in ground water were detected in Buena Vista County,

Iowa.

• Flufenacet was detected twice at stream sediment pore water, both instances in Nebraska,

with concentrations of up to 0.74 ppb detected in Colfax County.

• Flufenacet was detected at one distributed drinking water facility in Sandova County, NM at concentrations of up to 0.04 ppb. Details on the exact siting of concentrations

within influent or fi nished water was not provided.

An expanse of water monitoring information related to sampling of flufenacet’ s oxa late degradate in Minnesota is available from the STORET database . The sampling occurred between the years 2010

– 2013. No detections were f ound out of 2,069 samples.

There is a further expanse of monitoring data available from EPA’s PDP from drinking water facilities and gr ound water well for both flufenacet and its oxalate degradate. The monitoring data span from 2005 to 2013 and are sum marized below:

• Flufenacet was only detected once in finished surface water out of 964 samples. However, the magnitude of detection was really large at 75 ppb. This detection occurred

in Indiana in 2007 . Flufenacet was not sampled in ground water in the PDP.

• Flufenacet oxalate was detected 75 out of 1,363 samples in finished surface water, 71 out of 1,317 samples in untreated surface water, and 2 out of 1,767 samples in ground water. Flufenacet oxalate was found in concentrations up to 26 ppb in finish ed surface water, 21.3 ppb in untreated surface water, and 13 ppb in ground water. The highest magnitude and frequency of detections occurred with a vast majority within Ohio. However, there

were a few detections from a drinking water treatment facility in Louisiana and one detection in a ground water well located in Georgia.

11

### Furthermore, there is a targeted prospective ground water study conducted in shallow wells (15 to 25 ft. below ground surface) and deep wells (25 to 30 ft. below ground surface) fo r flufenacet, and its thiadone, oxalate, alcohol, and sulfonic acid degradates (MRID No. 46997402) . The monitoring study was conducted concurrent to a pre

- emergent application of Flufenacet in a corn field possessing silt loam soil located in the town of Minden in Central Nebraska during June of

1995. The monitoring data with each constituent is described below:

• Flufenacet was only detected one time at 0.04 ppb within 30 days of the application.

• The thiadone degradate was detected extensively but at lo w levels starting at 119 days after the application in both in shallow and deep wells. Concentrations ranged as high 0.18 ppb at 501 days after the application. T he t hiadone degradate was not detected after 1,155 days after the application.

• The alcohol d egradate of flufenacet was only detected one time at 0.02 ppb at 994 days after the application.

• The oxalate degradate was detected extensively but at low levels starting at 93 days after the application only in shallow wells. Concentrations ranged as hig h 0.12 ppb at 149 days after the application. The oxalate degradate was not detected after 501 days after the except for one trace isolated detection of 0.02 ppb at 994 days after the application.

• The sulfonic acid degradate was detected extensively but at low levels starting at 93 days after the application only in shallow wells. Concentrations ranged as high 0.66 ppb as late as 534 days after the application. The sulfonic acid degradate concentration of 0.37 ppb in shallow wells and 0.22 ppb were detec ted at the termination of the study at 1,473 days (4 years) after the application.

MODELING AND MONITORING CHARACTERIZATION

In general, both flufenacet EDWCs of surface water and ground water are higher by a large margin than the highest monitoring conce ntrations observed. For surface water, this may be due to a wide number of factors relating to lower vulnerabilities with rainfall, runoff, and drainage that may have been present at the surface water monitoring sites since the modeling scenarios depict t he most vulnerable sites. Furthermore, it is a likelihood that surface water monitoring are

not spatially or temporally targeted to applications especially as evident in their irregular sampling intervals in many cases. The ground water EDWC is purely a screening value for the entire country and is not specific for a certain crop. Therefore, ground water concentrations of flufenacet are expected to be lower than depicted by EDWCs and closer to the values as observed in the prospective ground water study. However, it should be noted that the site of this study was in Central Nebraska. Rainfall may occur more regularly at locations further east in the corn belt where flufenacet is used. Therefore, flufenacet ground water concentrations may be higher than observed in the Nebraska prospective ground water study.

12

### It should be noted that there was one isolated detection of flufenacet , identified in PDP data, at relatively high levels of 75 ppb in fin i shed water at a water treatment facility in Indiana in 2 007.

While this concentration is higher than the upper

- bound EDWC provided in this assessment, this

flufenacet concentration is isolated and as such may be re flective of a rare set of circumstances such as a high

- end runoff event which occurred in the are a at the time of this detection. It is

uncertain whether this value would represent a on e

- in

- ten y ear peak concentration given the relatively small temporal scope of the monitoring data available for flufenacet. However, this detection in Indiana provide s further evidence of flufenacet surface water exposure in an area where it is highly used.

REFERENCES

Barrett, M. 1997

. Proposal For a Method to Determine Screening Concentration Estimates for Drinking Water Derived from Gr ound Water Studies. EPA Off ice of Pesticide Programs. Washington, DC.

U.S. Environmental Protection Agency 2012. Guidance for using PRZM

- GW in Drinking Water Exposure Assessments. U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Environmental Fate and Effects Division. October 15, 2012

.

U.S. Enviro nmental Protection Agency 2012

.. Development and Use of Percent Cropped Area and Percent Turf Area Adjustment Factors in Drinking Water Exposure Assessments: 2012 Update . EPA Office of Pesticide Programs. Washington, DC.

U.S. Environmental Protection Agency 2012. Guidance for using PRZM

- GW in Drinking Water Exposure Assessments. U.S. Environmental Protection Agency, Office of Prevention, Pesticides

and To xic Substances, Office of Pesticide Programs, Environmental Fate and Effects Division. October 15, 2012

.

U.S. Enviro nmental Protection Agency 2014

. Surface Water Concentration Calculator User

Manual , Office of Prevention, Pesticides and Toxic Substanc es, Office of Pesticide Programs,

Environmental Fate and Effects Division. July 1, 2014

.

13

### APPENDIX A. ENVIRONMENTAL FATE AND TRANSPORT SUMMARY

Flufenacet can exist both in the dissolved phase and sorbed phase in soil, with K
oc 

### values ranging

from 209

– 762 mL/g (MRID No. 43441137) and aqueous solubility value of 56 mg/L. Therefore, flufenacet has the ability to reach surface water sources via runoff and erosion processes and groundwater sources via leaching as well. Flufenacet will not likely exist in the

vapor

- phase given its vapor pressure of 2.11 x 10

- 7 

### torr and Henry’s Law Constant of 2.12 x 10

- 8



### atm•m 3 

### /mol. Flufenacet is moderately persistent is soil and water with primary decline occurring due to biodegradation in aerobic environments over tim e. Flufenacet half

- lives range from 23.1 days

– 63.6 days in aerobic soil environments (MRID Nos. 43441141, 43441135, and 43850058)

and 18

– 77 days in aerobic aquatic environments (MRID Nos. 45796112 and 44580203).

Flufenacet is stable in anaerobic soil environments (MRID No. 43850059) and persistent in anaerobic aquatic systems with a half

- life of 492 days (MRID No. 43850060). Flufenacet is stable due to abiotic degradation processes including hydrolysis and photolysis in water and soil (43441134, 4385 0056, and 43850057). The molecular structure of flufenacet is show n in in Figure A

- 1 below.

F

F F

F C H 3

C

H C H 3

N N N

S O C H 2

O



### Figure A

- 1. Molecular structure for flufenacet.

In general, flufenacet breaks down in both soil and water by separati ng into anilide and thiadone components via cleavage of the CH 2 

### linkage (MRID Nos. 43441141, 43441135, 43850058, 45796112, 44580203). The entire thiadone group (right hand side of the parent molecule) remains completely entact and is persistent in aerobic and anaerobic aquatic environments with

half

- lives ranging between 160

- 303 days (MRID Nos. 4579110 and 45796111), but is more

labile in aerobic soil environments with half

- lives ranging 2.0

– 2.8 days (MRID No. 45796109). In both soil and water, the a nilide group (left hand side of the parent molecule) exhibits more complex serial degradation processes mainly to alcohol, methylsulfoxide, oxylate, and sulfonic acid by

- products. The anilide by

- products described above are all detected at major levels (g reater than 10 percent of applied) in the aerobic soil, anaerobic soil, aerobic aquatic, and anaerobic aquatic metabolism laboratory studies (MRID Nos. 43441141, 43441135, 43850058, 45796112, and 44580203). However, the thiadone degradate is only detected at major levels in water likely given its high persistence in aerobic and anerobic aquatic environments and more labile nature in aerobic soil environments (MRID Nos. 43441141, 43441135, 43850058,

14

### 45796112, 44580203, 4579110, 45796111, and 45796109). Ple ase refer to Tables A

- 1 and A

- 2 for detailed information on the formation and decline for all of the degradates in soil and water.

Both the thiadone degredate and flufenacet have been identified as the residues of concern in drinking water in consultation with HED. Given the thiadone degradate’s highly labile nature in soil, substantial translocation of the thiadone degradate via runoff and leaching to surface water and ground water, respectively, is not likely. However, the thiadone degradate is expecte d to form at high levels from biodegradation of flufenacet residues which reach surface water. Once the thiadone degradate forms, it is likely to be persistent in water for a long duration as indicated by its half

- life of 160

– 303 days in aerobic and ana erobic aquatic environments. It should be noted that as compared to flufenacet, a more substantial portion of the thiadone degradate material would likely remain in the water column rather than sorbed to sediment given

its K
oc 

### values in the range of 29

– 58 (MRID No. 43441140). The thaidone degradate in water is not anticipated to exist in the vapor

- phase given its Henry’s Law Constant of 1.2 x 10

- 7



### atm•m 3 

### /mol. The molecular structure of the thiadone degradate is shown in Figure A

- 2

.

F F

F O N H

S N



### Figure A

- 2

. Molecular structure for the flufenacate thiadone degradate.

15

### Table A

- 1. Flufenacet transformation product s

Transformation Product Name and

Structure Maximum Percent of Applied Dose (Interval) Percent of Applied Do se at final sampling interval (Interval) Study and

Guideline

number Comments

Aerobic Soil Metabolism

Transformation Product 1

Thiadone

5

- (Trifluoromethyl)

- 1,3,4

- thiadiazol

- 2(3H)

-

one

or 5

- Trifluoromethyl

- 1,3,4

- thiadiazol

- 2(3H)

- one

or 3

- Trifluorometh yl

- 1,3,4

- thiadiazol

- 2(3H)one 3.9% @ 7 d 0.9% @ 368 d 43441135

162

- 1 Thiadiazole label/sandy loam

Anaerobic Aquatic Metabolism

16.0% @ 99 d 16.0% @ 99 d 43850061

162

- 3 Thiadiazole label/pond water

sandy loam

A erob ic Aquatic Metabolism

84.3% @ 55 d 68.7% @ 156 d 45796112

162

- 4 Thiadiazole label/pond water

silty clay sediment (NESA; entire system)

63.8% @ 100 d 54.2% @ 156 d 45796112

162

- 4 Thiadiazole label/pond water

silty clay loam sediment (BRP;

entire system)

Field Dissipation Studies

Below LOD (<0.01 ppm) throughout study Below LOD (<0.01 ppm)

@ 554 d 43850062

164

- 1 North Carolina loamy sand (0

- 6 inches)

Below LOD (<0.01 ppm) throughout study Below LOD (<0.01 ppm)

@ 466 d 43850063

164

- 1 Wisconsin loamy sand (0

- 6 inches)

Prospective Ground Water Study

Below the LOQ (10 μg/kg ) throughout the study Below the LOQ (10 μg/kg) at 489 d 45907901

166

- 1 Sandy loam (0

- 6 inches)



### 16Transformation Product Name and

Structure Maximum Percent of Applied Dose (Interval) Percent of Applied Do se at final sampling interval (Interval) Study and

Guideline

number Comments

Transformation Product 2

Flufenacet methylsulfide

4

- Flu oro

- N

- methylethylanaline methylthioacetamide A erobic Aquatic Metabolism

11.4% @ 157 d 11.4% @ 157 d 44580203

162

- 4 Phenyl label/pond water

- silty clay loam sediment (NESA; entire ) 4.5% @ 157 d 4.5% @ 157 d 44580203

162

- 4 Phe nyl label/pond water

- silty clay loam sediment (BRP; entire system)

Transformation Product 3

Flufenacet oxalate

[(4

- Fluorophenyl)(1

- methylethyl)]amino]oxoacetic acid

or [(4

- Fluorophenyl)(1

- methylethyl)]amino]2

- oxoacetic acid Soil Ph otolysis

irradiated

- 0.6% @ 30 d

dark

- 4.6% @ 30 d irradiated

- 0.6% @ 30 d

dark

- 4.6% @ 30 d 43850057

161

- 3 Phenyl label /sandy loam

Aerobic Soil Metabolism

26.5% @ 365 d 26.5% @ 365 d 43441141

162

- 1 Phenyl label/sandy loam

6.6% @ 28 d Not detected @ 120 d 43850058

162

- 1 Phenyl label/loamy sand



### 17Transformation Product Name and

Structure Maximum Percent of Applied Dose (Interval) Percent of Applied Do se at final sampling interval (Interval) Study and

Guideline

number Comments

15.6% @ 28 d Not detected @ 120 d 43850058

162

- 1 Phenyl label/silt loam (Laacherhof)

10.0% @ 28 d Not detected @ 120 d 43850058

162

- 1 Phenyl label/silt loam (Hofchen)

13 .0% @ 46 d 11.7% @ 88 d 43850066

162

- 1 Phenyl label/fine sandy loam

7.6% @ 88 d 7.6% @ 88 d 43850066

162

- 1 Phenyl label/sandy loam

Anaerobic Soil Metabolism

14.5% @ 60 d 9.9% @ 210 d 43850059

162

- 2 Phenyl label/sandy loam

Aerobic Aqu atic Metabolism

4.6% @ 157 d 4.6% @ 157 d 44580203

162

- 4 Phenyl label/pond water

- silty clay loam sediment (NESA; entire system)

5.4% @ 157 d 5.4% @ 157 d 44580203

162

- 4 Phenyl label/pond water

- silty clay loam sediment (BRP; entire system)



### 18Transformation Product Name and

Structure Maximum Percent of Applied Dose (Interval) Percent of Applied Do se at final sampling interval (Interval) Study and

Guideline

number Comments

Ter restrial Field Dissipation

0.1 ppm @ 5 and 369 d Below LOD (<0.01 ppm)

@ 554 d 43850062

164

- 1 North Carolina loamy sand (0

- 6 inches)

0.01 ppm @ 27 and 369 d Below LOD (<0.01 ppm)

@ 466 d 43850063

164

- 1 Wisconsin loamy sand (0

- 6 inches)

Transfo rmation Product 4

Flufenacet sulfonic acid

4

- Fluoro

- N

- methylethylaniline

- sulfoacetamide

or
N

- Fluoro

- N

- methylethylaniline

- sulfoacetamide

or 2

- [(4

- Fluorophenyl)(1

- methylethyl)amino]

- oxoethylsulfonic acid Soil Photolysis

irradia ted

- 0.4% @ 15 d

dark

- 2.2% @ 30 d irradiated

- 0.3% @ 30 d

dark

- 2.2% @ 30 d 43850057

161

- 3 Phenyl label /sandy loam

Aerobic Soil Metabolism

7.7% @ 180 d 5.3% @ 365 d 43441141

162

- 1 Phenyl label/sandy loam

25.4% @ 100 d 22.6% @ 120 d 43850 058

162

- 1 Phenyl label/loamy sand

26.3% @ 100 d 21.8% @ 120 d 43850058

162

- 1 Phenyl label/silt loam (Laacherhof)

13.5% @ 100

- 120 d 13.5% @ 120 d 43850058

162

- 1 Phenyl label/silt loam (Hofchen)

2.4% @ 88 d 2.4% @ 88 d 43850066

162

- 1 Ph enyl label/fine sandy loam

1.3% @ 88 d 1.3% @ 88 d 43850066

162

- 1 Phenyl label/sandy loam



### 19Transformation Product Name and

Structure Maximum Percent of Applied Dose (Interval) Percent of Applied Do se at final sampling interval (Interval) Study and

Guideline

number Comments

Anaerobic Soil Metabolism

6.6% @ 30 d 4.5% @ 210 d 43850059

162

- 2 Phenyl label/sandy loam

Aerobic Aquatic Metabolism

1.65% @ 157 1.65% @ 15 7 d 44580203

162

- 4 Phenyl label/pond water

- silty clay loam sediment (NESA; water only)

3.2% @ 157 d 3.2% @ 157 d 44580203

162

- 4 Phenyl label/pond water

- silty clay loam sediment (BRP; entire system)

Terrestrial Field Dissipation

Below LOD (<0. 01 ppm) throughout study Not analyzed @ 554 d 43850062

164

- 1 North Carolina loamy sand (0

- 6 inches)

0.02 ppm @ 14 to 27 d Below LOD (<0.01 ppm)

@ 466 d 43850063

164

- 1 Wisconsin loamy sand (0

- 6 inches)

Prospective Ground Water

Below the LOQ ( 10 μg/kg) throughout the study Below the LOQ (10 μg/kg) at 489 d 45907901

166

- 1 Sandy loam (0

- 6 inches)

Transformation Product 5

Flufenacet methylsulfoxide

4

- Fluoro

- N

- methylethylanaline Soil Photolysis

irradiated

- 0.7 % @ 30 d

dark

- 0.6% @ 30 d irradiated

- 0.7% @ 30 d

dark

- 0.6% @ 30 d 43850057

161

- 3 Phenyl label



### 20Transformation Product Name and

Structure Maximum Percent of Applied Dose (Interval) Percent of Applied Do se at final sampling interval (Interval) Study and

Guideline

number Comments

methylsulfenylacetamide Aerobic Soil Metabolism

0.6% @ 28 d Not detected @ 365 d 43441141

162

- 1 Phenyl label/sandy loam

1.1% @ 28

- 56 d Not detected @ 120 d 43850 058

162

- 1 Phenyl label/loamy sand

3.5% @ 56 d 0.7% @ 120 d 43850058

162

- 1 Phenyl label/silt loam (Laacherhof)

1.5% @ 56 d 0.2% @ 120 d 43850058

162

- 1 Phenyl label/silt loam (Hofchen)

1.3% @ 88 d 1.3% @ 88 d 43850066

162

- 1 Phenyl labe l/fine sandy loam

0.9% @ 88 d 0.9% @ 88 d 43850066

162

- 1 Phenyl label/sandy loam

Aerobic Aquatic Metabolism

3.2% @ 157 d 3.2% @ 157 d 44580203

162

- 4 Phenyl label/pond water

- silty clay loam sediment (NESA; entire system)

2.2% @ 120 d 1.7 % @ 157 d 44580203

162

- 4 Phenyl label/pond water

- silty clay loam sediment (BRP; entire system)



### 21Transformation Product Name and

Structure Maximum Percent of Applied Dose (Interval) Percent of Applied Do se at final sampling interval (Interval) Study and

Guideline

number Comments

Transformation Product 6

Flufenacet methylsulfone

N

- (fluorophenyl)

- N

- (1

- methylethyl)

- 2

- (methylsulfonyl)acetamide

or 4

- Fluoro

- N

- methylethylaniline methylsu lfonylacetamide Aerobic Soil Metabolism

6.6% @ 100 d 4.7% @ 120 d 43850058

162

- 1 Phenyl label/loamy sand

4.3% @ 120 d 4.3% @ 120 d 43850058

162

- 1 Phenyl label/silt loam (Laacherhof)

5.6% @ 120 d 5.6% @ 120 d 43850058

162

- 1 Phenyl labe l/silt loam (Hofchen)

0.5% @ 46 d 0.3% @ 88 d 43850066

162

- 1 Phenyl label/fine sandy loam

Aerobic Aquatic Meta b olism

6.4% @ 100 d 5.3% @ 157 d 44580203

162

- 4 Phenyl label/pond water

- silty clay loam sediment (NESA; entire system)

7.2% @ 120 d 3.8% @ 157 d 44580203

162

- 4 Phenyl label/pond water

- silty clay loam sediment (BRP; entire system)

Transformation Product 7

Flefenacet thioglycolate sulfoxide Aerobic Soil Meta bolism

3.7% @ 180 d 2.8% @ 365 d 43441141

162

- 1 Phenyl label/sandy loam



### 22Transformation Product Name and

Structure Maximum Percent of Applied Dose (Interval) Percent of Applied Do se at final sampling interval (Interval) Study and

Guideline

number Comments

4

- Fluoro

- N

- methylethyl

- aniline sulfenyldiacetic acid amide 3.3% @ 56 d Not detected @ 120 d 43850058

162

- 1 Phenyl label/loamy sand

5.5% @ 28 d Not detected @ 120 d 43850058

162

- 1 Phenyl label/silt loam (Laacherhof)

1.9% @ 28 d Not detected @ 120 d 43850058

162

- 1 Phenyl label/silt loam (Hofchen)

Anaerobic Soil Metabolism

2.6% @ 30 d Not detected @ 210 d 43850059

162

- 2 Phenyl label/sandy loam

Aerobic Aquatic Metabolism

2.0% @ 157 d 2.0% @ 157 d 4458 0203

162

- 4 Phenyl label/pond water

- silty clay loam sediment (NESA; entire system)

1.89% @ 60 d 1.38% @ 157 d 44580203

162

- 4 Phenyl label/pond water

- silty clay loam sediment (BRP; entire system)

Transformation Product 8

Flufenacet alcohol

N

- (4

- fluorophenyl)

- 2

- hydroxyacetamide

or
N

- (4

- Fluorophenyl)

- 2

- hydroxy

- N

- (1

- methyl

Soil Photolysis

irradiated

- 1.0% @ 30 d

dark

- 0.4% @ 30 d irradiated

- 1.0% @ 30 d

dark

- 0.4% @ 30 d 43850057

161

- 3 Phen yl label

Aerobic Soil Metabolism

2.1% @ 44

- 65 d Not detected @ 365 d 43441141

162

- 1 Phenyl label/sandy loam



### 23Transformation Product Name and

Structure Maximum Percent of Applied Dose (Interval) Percent of Applied Do se at final sampling interval (Interval) Study and

Guideline

number Comments

ethyl)acetamide

8.1% @ 88 d 8.1% @ 88 d 43850066

162

- 1 Phenyl label/fine sandy loam

21.2% @ 88 d 21.2% @ 88 d 43850066

162

- 1 Phenyl label/s andy loam

Anaerobic Soil Metabolism

1.4% @ 153 d 0.9% @ 210 d 43850059

162

- 2 Phenyl label/sandy loam

Aerobic Aquatic Metabolism

0.7% @ 120 d 0.6% @ 157 d 44580203

162

- 4 Phenyl label/pond water

- silty clay loam sediment (NESA; entire

system )

1.3% @ 157 d 1.3% @ 157 d 44580203

162

- 4 Phenyl label/pond water

- silty clay loam sediment (BRP; entire system)

Terrestrial Field Dissipation

0.4 ppm @ 1 d Below LOD (<0.01 ppm)

@ 554 d 43850062

164

- 1 North Carolina/Pocalla loamy

sand

0

- 6 inches

0.01 ppm @ 1 to 14 d Below LOD (<0.01 ppm) 43850063 Wisconsin/ Dickinson sandy loam



### 24Transformation Product Name and

Structure Maximum Percent of Applied Dose (Interval) Percent of Applied Do se at final sampling interval (Interval) Study and

Guideline

number Comments

@ 466 d 164

- 1 0

- 6 inches

Prospective Ground Water

Below the LOQ (10 μg/kg) throughout the study Below the LOQ (10 μg/kg) at 489 d 45907901

166

- 1

Transformation Product 9

Flufenacet chloroacetanilide

N

- (4

- Fluorophenyl)

- 2

- chloro

- N

- (1

- methylethyl)acetamide Aerobic Soil Metabolism

5.1% @ 44 d Not detected @ 365 d 43441141

162

- 1 Phenyl label/sandy loam

0.4% @ 1 d 0.2% @ 88 d 43850066

162

- 1 Phenyl label/fine sandy loam

0.4% @ 27 d 0.2% @ 88 d 43850066

162

- 1 Phenyl label/sandy loam

Transformation Product 10

Flufenacet N

- isomer

N

- (4

- Fluorophenyl)

- N

- (1

- methylethyl)

- 5

- oxo

2

- (trifluoromethyl)

- 1,3,4

- thiadiazole

- 4(5H)

-
acet amide Soil Photolysis

irradiated

- 1.6% @ 8

- 15 d

dark

- 1.8% @ 15 d irradiated

- 1.6% @ 30 d

dark

- 1.5% @ 30 d 43850057

161

- 3 Phenyl label

Aerobic Soil Metabolism

2.0% @ 46 d 0.7% @ 88 d 43850066

162

- 1 Phenyl label/fine sandy loam



### 25Transformation Product Name and

Structure Maximum Percent of Applied Dose (Interval) Percent of Applied Do se at final sampling interval (Interval) Study and

Guideline

number Comments

1.4% @ 8 8 d 1.4% @ 88 d 43850066

162

- 1 Phenyl label/sandy loam

Transformation Product 11

Flufenacet thiol dimer

2,2'

- Dithiobis[N

- (4

- fluorophenyl)

- N

- (1

- methylethyl)acetamide] Aerobic Soil Metabolism

0.8% @ 27 d 0.7% @ 88 d 43850066

162

- 1 Phenyl l abel/fine sandy loam

Transformation Product 12

Flufenacet thioglycolate

4

- Fluoro

- N

- methylethylaniline thiodiacetic

acid amide Anaerobic Soil Metabolism

1.7% @ 60 d 1.4% @ 210 d 43850059

162

- 2 Phenyl label/sandy loam

Transformation Product 13

Flufenacet amine acetate

N

- (4

- Fluorophenyl)

- N(1

- methylethyl)acetamide Anaerobic Aquatic Metabolism

1.6% @ 63

- 91 d 1.6% @ 91 d 43850060

162

- 3 Phenyl label/pond water

- sandy

loam

Transformation Product 14

Thiadone

- acetate

5

- Trifluoromethyl

- 1,3,4

- thiad iazol

- 2

- oxy acetic acid Anaerobic Aquatic Metabolism

1.8% @ 99 d 1.8% @ 99 d 43850061

162

- 3 Thiadiazole label/pond water

sandy loam



### 26Transformation Product Name and

Structure Maximum Percent of Applied Dose (Interval) Percent of Applied Do se at final sampling interval (Interval) Study and

Guideline

number Comments

Transformation Product 15

FAIOCS and Flufenacet acid

Cysteine conjugate of 4'Fluoro

- N

isopropanolacetanilide and F OE oxalate Fish BCF

0.258 mg/kg @ 21 d (non

edible) 0.191 mg/kg @ 28 d (non

- edible) 43441127/

43441139

165

- 4 Pheny label/bluegill ( Lepomis

macrochirus )

Transformation Product 16

FACSO

3

- [[2

- 4

- [(4

- Fluorophenyl)(1

- methylethyl)amino]2

- oxoethyl]su lfinyl]analine Fish BCF

0.327 mg/kg @ 21 d (non

edible) 0.114 mg/kg @ 28 d (non

- edible) 43441127/

43441139

165

- 4 Pheny label/bluegill ( Lepomis

macrochirus )

Transformation Product 17

FANACSO

N

- Acetyl

- 3

- [[2

- [4

- fluorophenyl)(1

- nethylethyl)amino]

- 2

- oxoe thyl]sulfinyl]alanine Fish BCF

0.444 mg/kg @ 21 d (non

edible) 0.097 mg/kg @ 28 d (non

- edible) 43441127/

43441139

165

- 4 Pheny label/bluegill ( Lepomis

macrochirus )

Transformation Product 18

FOE GSH

N

- [2

- (Carboxmethyl)amino]

- 1

- [[[[2

- [(4

- fluor ophenyl)(1

- methylethyl)amino]

- 2

- oxoethyl]thio]methy]

- 2

- oxoethyl]glutamine Fish BCF

0.355 mg/kg @ 21 d (non

edible) 0.239 mg/kg @ 28 d (non

- edible) 43441127/

43441139

165

- 4 Pheny label/bluegill ( Lepomis

macrochirus )



### 27Transformation Product Name and

Structure Maximum Percent of Applied Dose (Interval) Percent of Applied Do se at final sampling interval (Interval) Study and

Guideline

number Comments

Transformation Product 19

FACS

S

- [ 2

- [(4

- Fluorophenyl)(1

- methylethyl)amino]

- 2

- oxoethyl]cysteine Fish BCF

5.719 mg/kg @ 28 d (non

edible) 5.719 mg/kg @ 28 d (non

- edible) 43441127/

43441139

165

- 4 Pheny label/bluegill sunfish ( Lepomis macrochirus )

0.692 mg/kg @ 21 d (edible) 0.63 1 mg/kg @ 28 d (edible) 43441127/

43441139

165

- 4 Pheny label/bluegill sunfish ( Lepomis macrochirus )

Transformation Product 20

FANACS

Nacetyl

- S

- [2

- [(4

- fluorophenyl)(1

- methylethyl)amino]

- 2

- oxoethyl]cysteine Fish BCF

2.431 mg/kg @ 28 d (non

edible) 2.431 mg/kg @ 28 d (non

- edible) 43441127/

43441139

165

- 4 Pheny label/bluegill sunfish ( Lepomis macrochirus )

0.326 mg/kg @ 21 d (edible) 0.260 mg/kg @ 28 d (edible) 43441127/

43441139

165

- 4 Pheny label/bluegill sunfish ( Lepomis macroc hirus )



### 28Transformation Product Name and

Structure Maximum Percent of Applied Dose (Interval) Percent of Applied Do se at final sampling interval (Interval) Study and

Guideline

number Comments

Transformation Product 21

Flufenacet GLU Fish BCF

0.52 mg/kg @ 21 d (non

edible) 0.467 mg/kg @ 28 d (non

- edible) 43441127/

43441139

165

- 4 Pheny label/bluegill sunfish ( Lepomis macrochirus )

Carbon dioxide Aerobic Soil Metabolism

50.9% @ 368 d 50.9% @ 368 d 43441135

162

- 1 Thiadiazole label/sandy loam

5.9% @ 365 d 5.9% @ 365 d 43441141

162

- 1 Phenyl label/sandy loam

14.2% @ 120 d 14.2% @ 120 d 43850058

162

- 1 Phenyl label/loamy sand

23.8% @ 1 20 d 23.8% @ 120 d 43850058

162

- 1 Phenyl label/silt loam (Laacherhof)

12.0% @ 120 d 12.0% @ 120 d 43850058

162

- 1 Phenyl label/silt loam (Hofchen)

Anaerobic Soil Metabolism

1.8% @ 210 d 1.8% @ 210 d 43850059

162

- 2 Phenyl label/sandy lo am



### 29Transformation Product Name and

Structure Maximum Percent of Applied Dose (Interval) Percent of Applied Do se at final sampling interval (Interval) Study and

Guideline

number Comments

Anaerobic Aquatic Metabolism

0.1% @ 91 d 0.1% @ 91 d 43850060

162

- 3 Phenyl label/pond water

- sandy

loam soil

1.4% @ 99 d 1.4% @ 99 d 43850061

162

- 3 Thiadiazole label/pond water

sandy loam soil

Aerobic Aquatic Metabolism

3.4% @ 157 d 3 .4% @ 157 d 44580203

162

- 4 Phenyl label/pond water

- silty clay loam sediment (NESA; entire system)

1.5% @ 157 d 1.5% @ 157 d 44580203

162

- 4 Phenyl label/pond water

- silty clay loam sediment (BRP; entire system)

15.3% @ 156 d 15.3% @ 156 d 45796 112

162

- 4 Thiadiazole label/pond water

silty clay sediment (NESA; entire system)

15.0% @ 156 d 15.0% @ 156 d 45796112

162

- 4 Thiadiazole label/pond water

silty clay loam sediment (BRP; entire system)

Nonextracted residues Aerobic Soil Metabolism

17.7% @ 271 d 16.5% @ 365 d 43441141

162

- 1 Phenyl label/sandy loam

6.9% @ 270 d 6.5% @ 368 d 43441135

162

- 1 Thiadiazole label/sandy loam



### 30Transformation Product Name and

Structure Maximum Percent of Applied Dose (Interval) Percent of Applied Do se at final sampling interval (Interval) Study and

Guideline

number Comments

24.4% @ 19 d 19.5% @ 88 d 43850066

162

- 1 Phenyl label/fine sandy loam

25.3% @ 88 d 25.3% @ 88 d 43850066

162

- 1 Phenyl label/sandy loam

42.3% @ 120 d 42.3% @ 120 d 43850058

162

- 1 Phenyl label/loamy sand

37.1% @ 120 d 37.1% @ 120 d 43850058

162

- 1 Phenyl label/silt loam (Laacherhof)

58.0% @ 120 d 58.0% @ 120 d 43850058

162

- 1 Phenyl label/silt loam (Hofchen)

Anaerobic Soil Metabolism

32.6% @ 210 d 32.6% @ 210 d 43850059

162

- 2 Phenyl label/sandy loam

Anaerobic Aquatic Metabolism

10.0% @ 63 d 6.0% @ 91 d 43850060

162

- 3 Phenyl label/pond water

- sandy

loam soil

0.6% @ 6 4

- 99 d 0.6% @ 99 d 43850061

162

- 3 Thiadiazole label/pond water

sandy loam soil



### 31Transformation Product Name and

Structure Maximum Percent of Applied Dose (Interval) Percent of Applied Do se at final sampling interval (Interval) Study and

Guideline

number Comments

Aerobic Aquatic Metabolism

28.5% @ 157 d 28.5% @ 157 d 44580203

162

- 4 Phenyl label/pond water

- silty clay loam sediment (NESA)

46.4% @ 157 d 46.4% @ 157 d 44 580203

162

- 4 Phenyl label/pond water

- silty clay loam sediment (BRP)

3.3% @ 55 d 2.2% @ 156 d 45796112

162

- 4 Thiadiazole label/pond water

silty clay sediment (NESA)

9.6% @ 100 d 7.5% @ 156 d 45796112

162

- 4 Thiadiazole label/pond water

silty cla y loam sediment (BRP)



### 32

### Table A

- 2 . Thiadone as the Test Material transformation products.

Transformation Product

Name and Structure Maximum Percent of Applied Dose (Interval) Percent of Applied Dose at final sampling interval (Interval) Study and

Gu ideline

number Comments

Transformation Product 1

Propionic acid conjugate of

thiadone Soil Photolysis

irradiated

- 6.1% @ 10 d

dark

- 12.0% @ 7 d irradiated

- 2.9% @ 14 d

dark

- 2.1% @ 14 d 45796108

161

- 3 Loamy sand soil

Aerobic Soil Metabolism

10.2% @ 2 d 0.1% @ 10 d 45796109

162

- 1 Loamy sand

7.0% @ 2 d 0.1% @ 10 d 45796109

162

- 1 Sandy loam

1.3% @ 1 d Not detected @ 14 d 45796109

162

- 1 Silt loam

Carbon Dioxide Soil Photolysis

irradiated

- 57.8% @ 14 d

dar k

- 57.6% @ 14 d irradiated

- 57.8% @ 14 d

dark

- 57.6% @ 14 d 45796108

161

- 3 Loamy sand soil

Aerobic Soil Metabolism

63.2% @ 10 d 63.2% @ 10 d 45796109

162

- 1 Loamy sand

82.1% @ 10 d 82.1% @ 10 d 45796109

162

- 1 Sandy loam

71.8% @ 14 d 71 .8% @ 14 d 45796109

162

- 1 Silt loam

Anaerobic Aquatic Metabolism

1.9% @ 303 d 1.9 % @ 303 d 45796110

162

- 3 Water

- silty clay sediment (entire system)



### 33Transformation Product

Name and Structure Maximum Percent of Applied Dose (Interval) Percent of Applied Dose at final sampling interval (Interval) Study and

Gu ideline

number Comments

Aerobic Aquatic Metabol i s m

10.9% @ 160 d 10.9% @ 160 d 45796111

162

- 4 Water

- silty clay sediment (entire system)

Nonextractable residues Aerobic Soil Metabolism

20.1% @ 7 d 19.5% @ 10 d 45796109

162

- 1 Loamy sand

8.4% @ 5 d 7.6% @ 10 d 45796109

162

- 1 Sandy loam

14.7% @ 7

- 14 d 14.7% @ 14 d 45796109

162

- 1 Silt loam

Anae robic Aqautic Metabolism

3.0% @ 61 d 0.8 % @ 303 d 45796110

162

- 3 Water

- silty clay sediment (entire system)

Aerobic Aquatic Metabolism

2.4% @ 160 d 2.4% @ 160 d 45796111

162

- 4 Water

- silty clay sediment (entire system)



### 34

### Appendix B

– Su rface Water Modeling

Figure A

- 1. Flufenacet SWCC output for IL Corn scenario.

Table 1. Estimated Environmental Concentrations (ppb) for Flufenacet_ILCorn.

Peak (1

- in

- 10 yr) 27.7

4

- day Avg (1

- in

- 10 yr) 26.9

21

- day Avg (1

- in

- 10 yr) 24.6

60

- day Avg (1

- i n

- 10 yr) 20.1

365

- day Avg (1

- in

- 10 yr) 7.16

Entire Simulation Mean 4.12

Table 2. Summary of Model Inputs for Flufenacet_ILCorn.

Scenario ILCornSTD

Cropped Area Fraction 1.0

Koc (ml/g) 434.4

Water Half

- Life (days) @ 25 °C 77.1

Benthic Half

- Life (day s) @ 25 °C 492

Photolysis Half

- Life (days) @ 45

°Lat 0

Hydrolysis Half

- Life (days) 0

Soil Half

- Life (days) @ 25 °C 48.2

Foliar Half

- Life (days) 0

Molecular Wt 363.6

Vapor Pressure (torr) 2.11e

- 7

Solubility (mg/l) 56

Table 3. Application Schedule f or Flufenacet_ILCorn.

Date (Days

Since Emergence) Type Amount (kg/ha) Eff. Drift

- 15 Ground 0.898 1.0 0.066

35

### Figure 1. Yearly Peak Concentrations

36

### Appendix C

– Ground Water Modeling

Figure C

- 1. PRZM

- GW output for WI Sands scenario with flufenacet

.

Table 1. Groundwater Results for Flufenacet_WISands and the Wisconsin Corn

- WI

Central Sands Scenario.

Peak Concentration (ppb) 12.4

Post

- Breakthrough Mean Concentration (ppb) 11

Entire Simulation Mean Concentration (ppb) 4.12

Average Breakthrough Time (days) 8188.552

Throughputs 1.338454

Table 2. Chemical Properties for Groundwater Modeling of Flufenacet_WISands.

Koc (ml/g) 434.4

Surface Soil Half Life (days) 48.2

Hydrolysis Half Life (days) 0

Diffusion Coefficint Air (cm2/day) 0 .0

Henry's Constant 0.0

Enthalpy (kcal/mol) 0.0

Table 3. Pesticide application scheme used for Flufenacet_WISands. This application scheme was applied every year of the simulation.

Application Days

Relative to Emergence Date (05/01) Application Method Application Rate

(kg/ha)

- 15 All pesticide placed at 5.08 cm

below surface 0.898

37

### Figure 1. Aquifer Breakthrough Curve for Flufenacet_WISands and the Wisconsin Corn

- WI Central Sands Scenario

38

### Figure C

- 2 . PRZM

- GW output for WI Sands scenario with flufenacet thiadone

.

Table 1. Groundwater Results for Thiadone and the Wisconsin Corn

- WI Central Sands

Scenario.

Peak Concentration (ppb) 0.0662

Post

- Breakthrough Mean Concentration (ppb) 0.0188

Entire Simulation Mean Concentration (ppb) 0. 0135

Average Breakthrough Time (days) 2953.866

Throughputs 3.710392

Table 2. Chemical Properties for Groundwater Modeling of Thiadone.

Koc (ml/g) 43.5

Surface Soil Half Life (days) 2.77

Hydrolysis Half Life (days) 0

Diffusion Coefficint Air (cm2/day ) 0.0

Henry's Constant 0.0

Enthalpy (kcal/mol) 0.0

Table 3. Pesticide application scheme used for Thiadone. This application scheme was applied every year of the simulation.

Application Days

Relative to Emergence Date (05/01) Application Method Applic ation Rate

(kg/ha)

- 15 All pesticide placed at 5.08 cm

below surface 0.02

39

### Figure 1. Aquifer Breakthrough Curve for Thiadone and the Wisconsin Corn

- WI Central

Sands Scenario

40

### Figure C

- 3 . SCI

- GROW output file for flufenacet and flufenacate thiadone

.

SCIGROW

VERSION 2.3

ENVIRONMENTAL FATE AND EFFECTS DIVISION

OFFICE OF PESTICIDE PROGRAMS

U.S. ENVIRONMENTAL PROTECTION AGENCY

SCREENING MODEL FOR AQUATIC PESTICI DE EXPOSURE

SciGrow version 2.3

chemical:flufenacet

time is 2/ 1/2015 13:41:42

------------------------------------------------------------------------ Application Number of Total Use Koc Soil Aerobic rate (lb/acre) applicat ions (lb/acre/yr) (ml/g) metabolism (days)

------------------------------------------------------------------------ 0.802 1.0 0.802 4.35E+01 48.2

------------------------------------------------------------------------ groundwater screening cond (ppb) = 9.37E

- 01

************************************************************************



### 41