UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

PC Code No.: 080302

DP Barcodes: 353319, 363812, 363820, 

363821, 363822, 363824, 369773, and 

391835

Date: July 8, 2011

MEMORANDUM

SUBJECT: Estimated Drinking Water Concentrations of the new chemical Fluopyram from 

Apples, Beans (dry), Cherries, Cucurbits, Grapes (wine), Peanut, Potato, Stone Fruits, Strawberry, 

Sugar beet, and Tree Nuts for the Use in Human Health Risk Assessment.

TO: Shaja Joyner, Risk Manager, RM20

Cynthia Giles-Parker, Branch Chief, 

Fungicide Branch, Registration Division (7505P)

AND Paula Deschamp, Branch Chief, RAB 3

Health Effects Division (7509P)

FROM: Mohammed A. Ruhman, Ph.D., 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.
2

It is noted that the registrant is seeking registration of fluopyram and its mixtures with other 

pesticides1for use as a fungicide to prevent and/or control fungus diseases on the crops listed on the 

subject of this Memo. Fluopyram belongs to the “pyramide” chemical class. The proposed highest 

single rate of application is 0.222 lb a.i/A with a maximum of 0.444 lb a.i./A/crop cycle (0.249 to 

0.498 Kg/Ha). Single and seasonal application rates may vary with the application procedure noting

that the minimum application intervals range from 5 to 14 days. 

Fluopyram is characterized by its high persistence in soil (90th percentile t1⁄2 = 464 days), practical 

stability in water/sediment systems, and low affinity to soil/sediment (Average Koc value of 439 

L/Kg). The chemical is not expected to partition in significant amountsinto the air from water in wet 

and dry soil (vapor pressure= 2.33 x 10-8torr and calculated Henry’s Law Constant= 7.59 x10-10 atm 

m

3 mol-1 at 25 °C). The degradation profile for fluopyram show very limited biotic/abiotic degradation 

occurring in laboratory soil systems and in laboratory aqueous systems affected by sunlight 

(represents shallow clear water systems). Although four environmental degradates were identified for 

fluopyram, the Global Residues of Concern Knowledgebase Subcommittee (Global ROCKS) decided 

that only parent is the residue of concern in drinking water exposure. The decision was based on the 

degradation profile of the parent which shows a very low level of degradation in important 

environmental compartments. 

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 SCIGROW (Screening Concentration in Ground Water) model was used for calculating the EDWCs from 

ground water sources. The estimates are presented in Table 1 for surface water (acute “peak” and 

non-cancer/cancer chronic values) and for groundwater. Parent was modeled using many scenarios 

with the maximum application rate, maximum number of applications and minimum intervals stated 

in the labels for fluopyram and its mixtures (input parameters are shown in Tables 3 and 4, below). 

Results in Table 1 are for the highest modeled concentrations. Appendix 1 contains all EDWCs from 

other standard scenarios representing all of the crop use patterns/application methods. Two modeling 

runs were executed for each scenario: one for aerial application and the other for ground or airblast 

applications. Ground application for all tree crops was assumed to be airblast.

Table 1 A list of the surface/ground water EDWC values for fluopyram (ppb).

Chemical

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

Acute/Chronic

Acute Peak (ppb) 1 Non-cancer/Chronic (Annual Mean) 2 Cancer/Chronic (Overall Annual Mean) 2

Fluopyram 12.97 4.90 3.487 0.319

1

Florida cucumber scenario results; 2 ME potato scenario results

 

1 MIX-1= Fluopyram/Tebuconazole 400 SC

MIX-2= Fluopyram/Trifloxystrobin 500 SC

MIX-3= Fluopyram/Pyrimethanil 500 SC

MIX-4= Fluopyram/Prothioconazole 400 500 SC
3

Based on the results above, the surface water acute 1-in-10 years peak EDWC is 12.97 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

acute/chronic, EDWCs is 0.319 ppb.

The above stated values represent upper-bound estimates of total concentrations that might be found 

in surface water and ground water due to the use of fluopyram as a fungicide in uses stated in the 

subject above. EDWCs stated in 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.

II. Environmental fate of Fluopyram

1. Fluopyram Parent

Based on abiotic laboratory studies, fluopyram is stable to photolysis on soil and to hydrolysis in 

acidic, neutral and alkaline systems (MRIDs 473723-06 and 473723-03/07, respectively). Aqueous 

photolysis is relatively slow and is not considered to be an important transformation route in the 

natural environment (t1⁄2= 57 days; MRID 473723-04). Laboratory metabolism data suggest that 

fluopyram is expected to be relatively persistent in major compartments of the environment including 

the aerobic/anaerobic soil systems (t1⁄2 ranged from 162 to 754 days, MRIDs 473723-07-09/stable; 

MRID 473723-10), aerobic/anaerobic water/sediment systems (t1⁄2= 648 to 1,470 daysfor aerobic and 

t1⁄2= 4,680 to 5,240 days “both considered stable”; MRIDs 473723-11/12 & 13), and air (estimated 

t1⁄2= 1.7 to 2.6 days; AOPWIN v 1.91). Although the chemical is highly persistent, the major route of 

fluopyram degradation in the environment is expected to be aerobic soil bio-transformation which is 

dominated by mineralization into CO2 (range of maximum formed from 5 to 27%). Other residues 

forming as a result of aerobic soil bio-transformation, include very limited amounts of four minor 

transformation products (1 to 4%) and un-identified bound residue (range of maximum formed: from 

8 to 15% within 1⁄3 to 1 year). The quantity formed of potential trifluorinated products is unknown 

because the ring containing one of the trifluorinated carbons was only uniformly radio-labeled in the 

submitted environmental fate studies. Appendix 2 contains discussion concerning trifluorinated

products. As stated previously, the chemical showed no significant degradation in aerobic or 

anaerobic water/sediment systems. 

Adsorption/desorption data suggest that fluopyram is moderately mobile (Koc: range= 316 to 591 mL

g

-1

; average= 439 mL g-1; MRID 473723-01). However, its relative high persistence increases the 

possibility for the chemical to be leached and to contaminate ground water and/or be carried by runoff to contaminate surface water. Field studies confirmed laboratory data on relative persistence in 

aerobic soil in at least four out of five field sites in the USA. Field dissipation half-lives in bareground plots were 24 days in GA and ranged from 83 to 589 days in ND, WA and NY (MRIDs 

475670-01/5). If plant uptake can be considered minimal (plant uptake was not measured in these 

studies), it could be stated that the major dissipation routes were degradation plus leaching at CA site; 
4

CF3 O

N

H

N

CF Cl 3

CF3 O

NH2

HO

N

CF Cl 3

O

CF3 O

N

H

N

CF Cl 3

OH

HO

N

CF S 3

O

O

H3C

degradation (biotic transformation) at GA site; leaching at WA site. No major routes could be 

identified for NY and ND sites. 

In conclusion, fluopyram is a relatively persistent chemical with moderate mobility and high 

solubility. Therefore, the chemical may contaminate ground water by leaching and surface water 

through run-off events.

1. Fluopyram Degradation Profile

Figure 1 summarizes degradation pathways/products for fluopyram.

Figure 1 Environmental degradation pathways for fluopyram 

 Fluopyram Parent

N

CF3

HN

O

F3C

 7-Hydroxy

Lactame Molecular Cleavage

Benzamide PCA

Methyl Sulfoxide

Chemical Names (Molecular Formula – Weight; No CAS number reported)

Limited aerobic soil degradation Very limited aqueous 
5

Lactame: 2,9-bis(trifluoromethyl)-6,7-dihydropyrido[2,3-e][2]benza-zocin-8(5H)-one [C16H10F6N2O - 360.26 g mol-1

]

7-Hydroxy: N-{2-[3-chloro-5-(trifluoromethyl)pyridin-2-yl]-2-hydroxyethyl}-2-(trifluoromethyl)benzamide [C16H11Cl F6N2O2

- 412.72 

g mol-1]

Benzamide: 2-(trifluoromethyl)benzamide [C8H6F3NO -189.14 g mol-1

]

PCA: 3-chloro-5-(trifluoromethyl)pyridine-2-carboxylic acid [C7H3Cl F3NO2 - 225.26 g mol-1

]

Methyl Sulfoxide: 3-(methylsulfinyl)-5-(trifluoromethyl)pyridine-2-carboxylic acid [C8H6F3NO3S - 253.20 g mol-1

]

Only four minor metabolites were identified in aerobic soil studies. Data suggest that parent 

fluopyram degrades into a transient transformation product, AE C656948-7-hydroxy in which the 

structure of the parent is preserved. The level of this transformation product appeared to remain low 

(reached maximum of 4.2% at 62 day with no clear decline) probably due to its transient nature. 

Transient transformation product appears to degrade by cleavage into two minor degradates the AE 

C656948-pyridyl-carboxylic acid “PCA” (reached maximum of 0.7% at 15 days with no clear 

decline) and AE C656948-benzamide “benzamide” (reached maximum of 1.1 % at 128 days with no 

clear decline). The minor degradate PCA appears to further degrade into the minor degradate methylsulfoxide (reached maximum of 1.0% at the end of the study with no clear decline). No definite 

conclusions are possible concerning persistence of these four “soil degradates” due to their low level 

of formation even in one year studies

As a result of photolysis, a fifth degradate, AE C656948-lactame “lactame” was formed as a major 

degradate in aqueous systems (maximum formed @ 23 days = 13%) and as a minor one on the soil 

system (maximum formed @ 23 days= 1.2%). Lactam is not expected to be a major degradate in 

most environmental compartments, except shallow and clear water bodies. This is due to the fact that 

fluopyram is practically stable to photolysis on soil and that aqueous photolysis is not considered to be

an important degradation pathway (mean t1⁄2= 57 days).

In the field, only three of the four soil degradates were tracked (methyl-sulfoxide was not tracked). 

The first is the transient transformation product 7-hydroxy which was observed at low concentrations 

ranging from a maximum of 0.7 to 3.0% (at day 6) which were similar to low concentrations observed 

in the laboratory. Although decline was observed in most sites, 7-hydroxy remained to be detected at 

the 1% level even at 665 days. Therefore, no clear decline can be ascertained for this compound. In

contrast, the other two degradates PCA and benzamide reached higher concentrations than the 

laboratory as they reached maximums of 1.2 to 18.6% and 0.8 to 16.2%, respectively, after 6-days of 

application in five different field sites. These two maximums were followed by rapid decline 

suggesting non-persistence of both under field conditions; especially that they were not leached. Nonpersistence is difficult to ascertain in field studies because of possible movement instead or along with 

degradation. Only biotransformation laboratory studies, with degradates as the test substance, may be 

used to infer persistence. No studies were submitted to clarify this uncertainty.

Mobility was not determined for fluopyram degradates with the exception of the transient product; the 

7-hydroxy. Based on an adsorption/desorption study for the 7-hydroxy, the compound can be 

considered as mobile (Koc: range= 86 to 159 mL g-1; average= 108 mL g-1; MRIDs 473723-02). 

However, the transient nature of the compound and the observed low concentrations in both 
6

laboratory and field studies preclude it from being important contaminant of either surface or ground 

waters. In contrast, PCA and benzamide degradates may form in substantial amounts in some field 

soils and may contaminate surface or ground waters in certain situations. This possibility remains 

uncertain because field studies may not be used to indicate persistence unless all possible dissipation 

routes are tracked. Table 2 contains a summary of environmental degradates formed in various 

laboratory and field studies.

Table 2 Summary of maximum amounts of degradates formed in environmental fate studies of 

fluopyram*

Degradate 1

Max. Degradate % of Applied (Time of Peak, day)

2

Aqueous & On soil Photolysis Aerobic Soil 3 Terrestrial Field Dissipation

7-Hydroxy 4.2% (62 d) 3.0% (62 d)

Pyridyl-carboxylic acid (PCA) 0.7% (15 d) 16% (6 d; declined)

Methyl-sulfoxide 1.0% (30-121 d) 1.0% (> year)

Benzamide 1.1% (128 d) 19% (6 d; declined)

Lactame 4

13% (23 d) & 1.2% (23 d)

1Refer to Figure 1 for chemical structures; No degradates were produced or identified in hydrolysis, 

anaerobic soil metabolism, aerobic and anaerobic aquatic studies. No ground water study was 

executed.

2 Blank cell indicates that degradate was not identified in the corresponding study

3

Low concentration levels, for ALL soil degradates, prevented conclusions on their persistence. 

However, it may be stated that all soil degradates shoe no clear decline.

4 High concentration is for aqueous photolysis and low concentration for photolysis on soil.

The degradation profiles for fluopyram in most important environmental compartments (soil and 

water/sediment systems) reveals that potential contaminant degradates to surface/ground water are

those produced from aerobic soil degradation including pyridyl-carboxylic acid (PCA), methylsulfoxide, and benzamide. However, production of these degradates are limited because of the relative 

stability of the parent. In this respect, it should be stated that relatively high degradation occured at 

two sites in the field producing the degradates PCA and benzamide at relatively high levels in the first 

week after application (16-19% of the applied). However, data suggest a clear decline following these 

observed maximums.

III. Estimating Drinking Water Exposure from Surface Water Sources

Fluopyram is a new insecticide and no surface water monitoring data is available. The Agency based 

this report on simulated screening values using Tier II PRZM/EXAMS. The screening assessment for 

fluopyram was completed using Tier II PRZM/EXAMS program for drinking water. The approach 

was to perform a model run for most of the crop use patterns. Input values for the run is summarized 

in Table 3.
7

Table 3 Summary of PRZM/EXAMS input parameters for modeling fluopyram

Input Parameter 1(Unit) Value* Reference (MRID No.)

Molecular Weight g/mole 396.72 Product chemistry

Henry’s constant (atm-m

3 mol-1 @ 20 oC) 2.94E-10 Product chemistry

Solubility in Water(mg/L) 16 Product chemistry

Photolysis in Water (t1⁄2 in days @ pH 7) 57 473723-04

Aerobic Soil Metabolism (90th % t1⁄2 in days) 464 473723-07 to 09

Hydrolysis (90th % t1⁄2 in days) Stable 473723-03/07

Aerobic Aquatic Metabolism (Whole system t1⁄2 in days) 1,360 473723-11

Anaerobic Aquatic Metabolism (Whole system t1⁄2 in days) 1,757 473723-12/13

Koc (Average in L/Kg) 439 473723-01

Application rate and frequency

Application intervals Depends on the crop label

Chemical Application Method (CAM) 2

Parameter Guidance2

Application Efficiency

95% for aerial

99% for ground

Spray Drift Fraction

Aerial (0.16)

Ground: Airblast 

(0.063) and 

others (0.064), 

Drip 0%

Background information on the linked PRZM/EXAM is included in Appendix 3 and the chosen 

highest model run in Appendix 4.

IV. Estimating Drinking Water Exposure from Ground Water Sources

Fluopyram is a new insecticide and no ground water monitoring data is available. The Agency used 

Tier I SCI-GROW model, a high exposure tier one model, for arriving at the Estimated Drinking 

Water Concentration (EDWC) for this chemical in ground water sources. Background information on 

SCI-GROW model is included in Appendix 3 and input/output values are summarized in Tables 4

and 5, respectively

 

2 Guidance for Selecting Input Parameters in Modeling the Environmental Fate and Transport of Pesticides. 

URL http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm
8

Table 4 Summary of SCI-GROW input parameters for fluopyram

Parameter Value* Reference (MRID Number)

Application Rate (lb a.i./acre)

Number of Applications/Year

0.222 x 2

And

0.112 x 4

Maximum label rate= 0.0754 lbs a.i/A first application and 

three applications at 0.1247 lbs a.i/A a total of 0.4495 lbs 

a.i/A/Crop cycle. Input has to be equal amounts therefore 

two entries were used: 2 applications at 0.22475 lbs a.i/A 

each (total 0.4495 lbs) and 4 applications at 0.112375 each 

(total 0.4495 lbs). Value chosen is that giving the highest 

EDWC

Aerobic Soil Metabolism t1⁄2 (days) 294.5 Median of 12 values (MRID 473723-07 to 09)

Koc (L Kg-1) 397.0 Median of 5 values (MRID 473723-01)

* As per Guidance for Selecting Input Parameters in Modeling the Environmental Fate and Transport of Pesticides. 

Referenced above

Table 5 Summary of output from SCI-GROW for fluopyram

Parameter Value* Reference

EDWC with two applications 3.19 x 10 -1 Output form model run

EDWC with two applications 3.19 x 10 -1 Output form model run
9

APPENDIX 1: Summary Table of EDWCs for Labeled Use Patterns

Ground Application (PCA adjustment was applied for all = 0.87)

Crop Scenario

Single Application Rate

Number of 

Applications

Date of 1st

Application

EDWC (ppb)

lb a.i./A Kg a.i./ha Peak Yearly All Years

Apples, Ground NC apple 0.222 0.249 2 15-05 12.52 4.042 2.127

Apples, Ground OR apple 0.222 0.249 2 15-05 2.27 1.595 1.264

Apples, Ground PA apple 0.222 0.249 2 15-05 8.35 3.931 2.491

Apples, Ground CA fruits 0.222 0.249 2 15-04 4.06 3.192 2.643

Beans (dry), Ground MI beans 0.134 0.15 2 01-08 10.35 3.805 2.351

Cherries Only, Ground MI cherries 0.092 0.103 2 10-07 3.79 2.764 1.756

Cherries Only, Ground CA fruits 0.092 0.103 2 30-04 1.52 1.247 1.000

Cucurbits, Ground FL cucumber 0.222 0.249 2 20-11 12.97 2.635 1.297

Cucurbits, Ground MI melon 0.222 0.249 2 01-07 5.60 4.219 2.392

Cucurbits, Ground MO melon 0.222 0.249 2 25-06 10.38 2.685 1.184

Cucurbits, Ground NJ melon 0.222 0.249 2 01-07 5.86 2.956 1.840

Cucurbits, Drip FL cucumber 0.222 0.249 2 20-11 12.97 2.635 1.297

Cucurbits, Drip MI melon 0.222 0.249 2 01-07 4.73 3.291 1.505

Cucurbits, Drip MO melon 0.222 0.249 2 25-06 9.36 2.426 0.927

Cucurbits, Drip NJ melon 0.222 0.249 2 01-07 4.83 2.457 1.351

Grapes (Wine), Ground CA wine grapes 0.222 0.249 2 01-04 4.32 3.274 2.685

Grapes (Wine), Ground NY grapes 0.222 0.249 2 15-04 7.99 4.606 3.311

Peanuts, Ground NC peanut 0.222 0.249 2 15-07 7.90 3.017 2.339

Potatoes, Ground IDN potato 0.178 0.199 2 20-06 4.17 2.809 2.565

Potatoes, Ground ME potato 0.178 0.199 2 01-07 7.92 4.900 3.487

Stone Fruits, Ground CA fruits 3 0.092 0.103 4 25-04 2.95 2.435 1.991

Stone Fruits, Ground GA peaches 0.092 0.103 4 20-04 3.33 1.595 1.114

Strawberry Drip FL strawberry 0.222 0.249 2 01-12 8.14 1.543 0.963

Sugerbeet, Ground MN sugerbeet 0.112 0.125 2 01-05 4.80 3.633 2.784

Tree Nuts, Ground CA almond 0.222 0.249 2 20-02 3.48 1.876 1.405

Tree Nuts, Ground GA pecans 0.222 0.249 2 01-08 10.19 2.421 1.497

Tree Nuts, Ground OR Filberts 0.222 0.249 2 20-03 4.56 2.384 1.666
10

Aerial Application (PCA adjustment was applied for all = 0.87)

Crop Scenario

Single Application Rate

Number of 

Applications

Date of 1st

Application

Peak

EDWC (ppb)

lb a.i./A Kg a.i./ha Yearly

All 

Years 60-day

Beans (dry) MI beans 0.134 0.15 2 01-08 10.94 4.13 2.72

Cherries Only MI cherries 0.092 0.103 2 10-07 4.58 3.39 2.38

Cherries Only CA fruits 2 0.092 0.103 2 30-04 3.56 2.88 2.47

Peanuts NC peanut 0.222 0.249 2 15-07 8.98 3.56 2.89

Potatoes IDN potato 0.092 0.103 3 20-06 4.82 3.26 3.06

Potatoes ME potato 0.092 0.103 3 01-07 6.84 4.25 3.08

Tree Nuts CA almond 0.222 0.249 2 20-02 5.42 2.95 2.46

Tree Nuts GA pecans 0.222 0.249 2 01-08 11.17 2.67 1.78

Tree Nuts OR Filberts 0.222 0.249 2 20-03 6.36 3.32 2.62
11

APPENDIX 2: Trifluorinated Products

In submitted fate/transport studies, Fluoropyram was uniformly labeled in only one of the rings 

containing the trifluorinated carbon"; therefore, the formation and decline of potential 

trifluorinated degradation products is unknown. Trifluoroacetic acid (CAS 76-05-1) is a potential 

degradation product that is shared by other pesticides (e.g., benfluralin, trifloxystrobin, fluometuron, 

and thiafluamide/flufenacet), hydrochlorofluorocarbons (HCFC), and hydrofluorocarbons (HFC). 

According to the Hazardous Substances Data Bank, with a vapor pressure of 110 torr at 25°C, 

trifluoroacetic acid will volatilize if released to the air or dry soil (USNIH, 2009). It’s half-life in air 

is estimated at 31 days due to reaction with hydroxyl radicals. However, if released to water bodies or 

wet soil, trifluoroacetic acid will form a persistent anion (pKa of 0.52) that will not degrade by abiotic 

or microbial means. The compound has been detected in surface water, seawater, and precipitation 

(USNIH, 2009). Therefore, there is an exposure concern of water bodies persistently contaminated 

with trifluoroacetic acid from sources including degrading fluopyram residues in water bodies.

Fluoroform (trifluoromethane; CAS 75-46-7) is also a possible terminal product of the trifluorinated 

degradates of fluopyram. According to the Hazardous Substances Data Bank, fluoroform will 

volatilize from water and soil based on a Henry's Law constant of 0.095 atm-m

3

/mol and a vapor 

pressure of 3.5 x 104torr at 25°C (USNIH, 2009). However, the compound has been detected in 

surface water and ground water. It will persist in air with a half-life of 180 years and gradually diffuse 

into the stratosphere with a half-life of 20 years (USNIH, 2009). As an HFC, fluoroform is included 

with the greenhouse gases subject to the Kyoto Protocol (United Nations, 1998, EPA 2009).

United Nations. 1998. Kyoto Protocol to the United Nations Framework Convention on Climate 

Change. Online at: http://unfccc.int/resource/docs/convkp/kpeng.pdf

United States National Institutes of Health (USNIH). 2009. Hazardous Substances Data Bank. 

United States National Institutes of Health, National Library of Medicine, Specialized 

Information Services, Environmental Health and Toxicology, Toxicology Data Network 

(TOXNET®), Hazardous Substances Data Bank (HSDB®). Last updated: Jun. 12, 2008. 

Online at: http://toxnet.nlm.nih.gov/

US EPA 2009. “Adoption Proposed Endangerment and Cause or Contribute Findings for 

Greenhouse Gases Under Section 202(a) of the Clean Air Act”, in Federal Register, Vol. 74, No. 

78, 2009, pp. 18886 - 18910. US EPA, Office of Air and Radiation. Washington, DC. 
12

APPENDIX 3: Background Information on the Models

a. PRZM and EXAMS models and the Index Reservoir Scenario

The linked PRZM and EXAMS models are used in this case as a second tier screen designed to 

estimate the pesticide concentrations found in water for use in drinking water assessments. They

provide high-end values on the concentrations that might be found in a small drinking water reservoir 

due to the use of pesticide. The Drinking Water Index Reservoir scenario includes a 427 acres field 

immediately adjacent to a 13 acres reservoir, 9 feet deep, with continuous site-specific flow. This 

amount can be reduced due to degradation in field and the effect of binding to soil. Spray drift is 

equal to 6.4% of the applied concentration from the ground spray application and 16% for aerial 

applications.

The PRZM/EXAMS modeling system with the Index Reservoir scenario also makes adjustments for 

the percent cropped area. While it is assumed that the entire watershed would not be treated, the use 

of a PCA is still a screen because it represents the highest percentage of crop cover of any large 

watershed in the US, and it assumes that the entire crop is being treated. Various other conservative 

assumptions of this scenario include the use of a small drinking water reservoir surrounded by a

runoff-prone watershed, the use of the maximum use rate and no buffer zone.

b. SCI-GROW

SCI-GROW is a screening model which the Office of Pesticide Programs (OPP) in EPA frequently

uses to estimate pesticide concentrations in vulnerable ground water. The model provides an exposure 

value which is used to determine the potential risk to the environment and to human health from 

drinking water contaminated with the pesticide. The SCI-GROW estimate is based on environmental 

fate properties of the pesticide (aerobic soil degradation half-life and linear adsorption coefficient 

normalized for soil organic carbon content), the maximum application rate, and existing data from 

small-scale prospective ground-water monitoring studies at sites with sandy soils and shallow ground 

water.

Pesticide concentrations estimated by SCI-GROW represent conservative or high-end exposure values 

because the model is based on ground-water monitoring studies which were conducted by applying 

pesticides at maximum allowed rates and frequency to vulnerable sites (i.e., shallow aquifers, sandy, 

permeable soils, and substantial rainfall and/or irrigation to maximize leaching). In most cases, a large 

majority of the use areas will have ground water that is less vulnerable to contamination than the areas 

used to derive the SCI-GROW estimate. SCI-GROW provide a groundwater screening exposure value 

to be used in determining the potential risk to human health from drinking water contaminated with 

the pesticide. SCI-GROW estimates likely groundwater concentrations if the pesticide is used at the 

maximum allowable rate in areas where groundwater is exceptionally vulnerable to contamination. In 

most cases, a large majority of the use area will have groundwater that is less vulnerable to 

contamination than the areas used to derive the SCI-GROW estimate.
13

APPENDIX 4: Example of a Model Run

PRZM EXAMS MODEL RUNS: Highest Peak (FL Cucumber Ground)

stored as FluoprymDW.out

Chemical: Fluopyram

PRZM environment: 

FLcucumberSTD.txt modified Wedday, 13 June 2007 at 12:19:24

EXAMS environment: ir298.exv modified Tueday, 26 August 2008 at 06:14:08

Metfile: w12844.dvf modified Tueday, 26 August 2008 at 06:14:22

Water segment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 1.121 1.07 0.961 0.5564 0.3709 0.09146

1962 3.421 3.269 2.807 2.127 1.751 0.8643

1963 8.385 4.354 2.483 1.274 1.128 0.7284

1964 12.07 11.84 10.89 6.521 4.419 2.568

1965 6.88 6.629 5.667 4.34 3.633 1.463

1966 8.742 8.351 7.517 5.94 5.104 1.881

1967 3.949 3.78 3.17 2.849 2.579 1.108

1968 1.807 1.73 1.451 1.103 0.9258 0.5269

1969 6.812 6.561 5.725 4.394 4.006 1.987

1970 9.627 9.207 7.831 6.079 5.28 2.054

1971 2.624 2.513 2.073 1.561 1.283 0.715

1972 3.419 3.269 2.761 2.217 1.908 0.8736

1973 2.773 2.652 2.462 2.076 1.813 0.7877

1974 9.695 9.256 8.122 5.805 4.763 1.854

1975 2.703 2.59 2.18 1.559 1.271 0.602

1976 4.087 3.908 3.551 2.586 2.112 0.9204

1977 11.47 10.96 9.86 6.104 4.129 1.916

1978 8.207 7.862 6.745 5.168 4.229 1.737

1979 6.009 5.739 4.772 3.297 2.662 1.358

1980 7.733 7.395 6.19 4.892 4.167 1.966

1981 6.02 3.459 2.921 2.304 2.281 1.053

1982 5.925 5.661 4.963 3.653 3.424 1.438

1983 7.144 6.893 6.053 4.608 3.866 1.645

1984 31.31 30.23 25.61 14.25 9.559 3.422

1985 13.29 12.76 10.82 7.822 6.78 3.08

1986 20.65 19.71 16.63 7.974 5.515 3.161

1987 15.09 14.45 12.14 8.607 6.983 2.498

1988 2.873 2.751 2.339 1.903 1.705 0.7532

1989 4.91 4.69 2.455 1.208 1.032 0.7068
14

1990 4.036 3.859 3.445 2.572 2.296 0.9783

Sorted results

Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly

0.032258 31.31 30.23 25.61 14.25 9.559 3.422

0.064516 20.65 19.71 16.63 8.607 6.983 3.161

0.096774 15.09 14.45 12.14 7.974 6.78 3.08

0.129032 13.29 12.76 10.89 7.822 5.515 2.568

0.16129 12.07 11.84 10.82 6.521 5.28 2.498

0.193548 11.47 10.96 9.86 6.104 5.104 2.054

0.225806 9.695 9.256 8.122 6.079 4.763 1.987

0.258065 9.627 9.207 7.831 5.94 4.419 1.966

0.290323 8.742 8.351 7.517 5.805 4.229 1.916

0.322581 8.385 7.862 6.745 5.168 4.167 1.881

0.354839 8.207 7.395 6.19 4.892 4.129 1.854

0.387097 7.733 6.893 6.053 4.608 4.006 1.737

0.419355 7.144 6.629 5.725 4.394 3.866 1.645

0.451613 6.88 6.561 5.667 4.34 3.633 1.463

0.483871 6.812 5.739 4.963 3.653 3.424 1.438

0.516129 6.02 5.661 4.772 3.297 2.662 1.358

0.548387 6.009 4.69 3.551 2.849 2.579 1.108

0.580645 5.925 4.354 3.445 2.586 2.296 1.053

0.612903 4.91 3.908 3.17 2.572 2.281 0.9783

0.645161 4.087 3.859 2.921 2.304 2.112 0.9204

0.677419 4.036 3.78 2.807 2.217 1.908 0.8736

0.709677 3.949 3.459 2.761 2.127 1.813 0.8643

0.741935 3.421 3.269 2.483 2.076 1.751 0.7877

0.774194 3.419 3.269 2.462 1.903 1.705 0.7532

0.806452 2.873 2.751 2.455 1.561 1.283 0.7284

0.83871 2.773 2.652 2.339 1.559 1.271 0.715

0.870968 2.703 2.59 2.18 1.274 1.128 0.7068

0.903226 2.624 2.513 2.073 1.208 1.032 0.602

0.935484 1.807 1.73 1.451 1.103 0.9258 0.5269

0.967742 1.121 1.07 0.961 0.5564 0.3709 0.09146

0.1 14.91 14.281 12.015 7.9588 6.6535 3.0288

PCA= 0.87; PEAK= 0.87 x 

14.91= 12.97 nputs 

generated by pe5.pl -

Novemeber 2006

Average of yearly 

averages: 1.491235
15

PRZM EXAMS MODEL RUNS: Highest Yearly & All Years (ME 

Potatoes)

Data used for this run:

Output File: FluoprymDW

Metfile: w12844.dvf

PRZM scenario: FLcucumberSTD.txt

EXAMS environment file: ir298.exv

Chemical Name: Fluopyram

Description

Variable 

Name Value Units Comments

Molecular weight mwt 396.72 g/mol

Henry's Law Const. henry 2.94E-10 atm-m^3/mol

Vapor Pressure vapr torr

Solubility sol 16 mg/L

Kd Kd mg/L

Koc Koc 439 mg/L

Photolysis half-life kdp 57 days

Halflife

Aerobic Aquatic Metabolism kbacw 1360 days Halfife

Anaerobic Aquatic Metabolism kbacs 1757 days Halfife

Aerobic Soil Metabolism asm 464 days Halfife

Hydrolysis: pH 5 0 days

Halflife

Hydrolysis: pH 7 0 days

Halflife

Hydrolysis: pH 9 0 days

Halflife

Method: CAM 2 integer See PRZM manual

Incorporation Depth: DEPI 0 cm

Application Rate: TAPP 0.25 kg/ha

Application Efficiency: APPEFF 0.99 fraction

Spray Drift DRFT 0.064 fraction of application rate applied to pond

Application Date Date 20-11 dd/mm or dd/mmm or dd-mm or dd-mmm

Interval 1 interval 5 days Set to 0 or delete line for single app.

app. rate 1 apprate kg/ha

Record 17: FILTRA

IPSCND 1

UPTKF

Record 18: PLVKRT

PLDKRT 0.131

FEXTRC 0.5
16

Flag for Index Res. Run IR Reservoir

Flag for runoff calc. RUNOFF total none, monthly or total(average of entire run)

stored as FluoprymDW.out

Chemical: Fluopyram

PRZM environment: 

MEpotatoSTD.txt modified Tueday, 29 May 2007 at 12:56:18

EXAMS environment: 

ir298.exv modified Tueday, 26 August 2008 at 05:14:08

Metfile: w14607.dvf modified Tueday, 26 August 2008 at 05:14:52

Water segment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 4.651 4.574 4.292 3.839 3.671 1.429

1962 8.779 8.658 8.306 7.661 7.328 4.308

1963 6.32 6.242 6.106 5.869 5.848 4.691

1964 5.956 5.885 5.689 5.354 5.068 4.271

1965 5.042 4.991 4.785 4.382 4.125 3.456

1966 4.36 4.296 4.048 3.745 3.349 2.429

1967 6.512 6.426 6.183 5.782 5.556 3.647

1968 6.095 6.022 5.828 5.454 5.17 4.109

1969 8.311 8.191 7.734 6.947 6.64 4.778

1970 9.294 9.152 8.645 7.692 7.119 4.721

1971 5.487 5.433 5.217 4.812 4.559 3.711

1972 6.68 6.58 6.193 5.729 5.522 3.453

1973 6.808 6.726 6.399 5.897 5.599 4.086

1974 5.09 5.036 4.82 4.418 4.248 3.547

1975 3.873 3.824 3.634 3.368 3.252 2.57

1976 9.139 9.012 8.543 7.849 7.695 4.648

1977 7.569 7.463 7.357 6.961 6.862 5.049

1978 8.522 8.442 8.19 7.579 7.262 4.995

1979 6.895 6.802 6.635 6.013 5.692 4.652

1980 5.234 5.171 4.946 4.563 4.422 3.679

1981 16.05 15.77 14.76 12.92 12.04 5.926

1982 8.819 8.718 8.4 8.239 8.04 6.343

1983 8.553 8.448 8.035 7.706 7.445 5.697

1984 6.035 5.98 5.734 5.214 4.934 4.29

1985 4.61 4.552 4.412 4.058 3.816 3.058

1986 5.827 5.744 5.447 5.122 4.905 3.538

1987 3.732 3.687 3.539 3.306 3.268 2.927

1988 3.879 3.827 3.675 3.458 3.319 2.811
17

1989 7.022 6.943 6.541 5.886 5.455 3.34

1990 7.646 7.541 7.144 6.575 6.241 4.099

Sorted results

Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly

0.032258 16.05 15.77 14.76 12.92 12.04 6.343

0.064516 9.294 9.152 8.645 8.239 8.04 5.926

0.096774 9.139 9.012 8.543 7.849 7.695 5.697

0.129032 8.819 8.718 8.4 7.706 7.445 5.049

0.16129 8.779 8.658 8.306 7.692 7.328 4.995

0.193548 8.553 8.448 8.19 7.661 7.262 4.778

0.225806 8.522 8.442 8.035 7.579 7.119 4.721

0.258065 8.311 8.191 7.734 6.961 6.862 4.691

0.290323 7.646 7.541 7.357 6.947 6.64 4.652

0.322581 7.569 7.463 7.144 6.575 6.241 4.648

0.354839 7.022 6.943 6.635 6.013 5.848 4.308

0.387097 6.895 6.802 6.541 5.897 5.692 4.29

0.419355 6.808 6.726 6.399 5.886 5.599 4.271

0.451613 6.68 6.58 6.193 5.869 5.556 4.109

0.483871 6.512 6.426 6.183 5.782 5.522 4.099

0.516129 6.32 6.242 6.106 5.729 5.455 4.086

0.548387 6.095 6.022 5.828 5.454 5.17 3.711

0.580645 6.035 5.98 5.734 5.354 5.068 3.679

0.612903 5.956 5.885 5.689 5.214 4.934 3.647

0.645161 5.827 5.744 5.447 5.122 4.905 3.547

0.677419 5.487 5.433 5.217 4.812 4.559 3.538

0.709677 5.234 5.171 4.946 4.563 4.422 3.456

0.741935 5.09 5.036 4.82 4.418 4.248 3.453

0.774194 5.042 4.991 4.785 4.382 4.125 3.34

0.806452 4.651 4.574 4.412 4.058 3.816 3.058

0.83871 4.61 4.552 4.292 3.839 3.671 2.927

0.870968 4.36 4.296 4.048 3.745 3.349 2.811

0.903226 3.879 3.827 3.675 3.458 3.319 2.57

0.935484 3.873 3.824 3.634 3.368 3.268 2.429

0.967742 3.732 3.687 3.539 3.306 3.252 1.429

0.1 9.107 8.9826 8.5287 7.8347 7.67 5.6322

Average of yearly

averages: 4.0086

Inputs generated by pe5.pl - Novemeber 2006
18

Data used for this run:

Output File: FluoprymDW

Metfile: w14607.dvf

PRZM scenario: MEpotatoSTD.txt

EXAMS environment file: ir298.exv

Chemical Name: Fluopyram

Description

Variable 

Name Value Units Comments

Molecular weight mwt 396.72 g/mol

Henry's Law Const. henry 2.94E-10 atm-m^3/mol

Vapor Pressure vapr torr

Solubility sol 16 mg/L

Kd Kd mg/L

Koc Koc 439 mg/L

Photolysis half-life kdp 57 days

Halflife

Aerobic Aquatic Metabolism kbacw 1360 days Halfife

Anaerobic Aquatic 

Metabolism kbacs 1757 days Halfife

Aerobic Soil Metabolism asm 464 days Halfife

Hydrolysis: pH 5 0 days

Halflife

Hydrolysis: pH 7 0 days

Halflife

Hydrolysis: pH 9 0 days

Halflife

Method: CAM 2 integer See PRZM manual

Incorporation Depth: DEPI 0 cm

Application Rate: TAPP 0.199 kg/ha

Application Efficiency: APPEFF 0.99 fraction

Spray Drift DRFT 0.064 fraction of application rate applied to pond

Application Date Date 7-Jan dd/mm or dd/mmm or dd-mm or dd-mmm

Interval 1 interval 5 days Set to 0 or delete line for single app.

app. rate 1 apprate kg/ha

Record 17: FILTRA

IPSCND 1

UPTKF

Record 18: PLVKRT

PLDKRT 0.131

FEXTRC 0.5

Flag for Index Res. Run IR Reservoir
19

Flag for runoff calc. RUNOFF total none, monthly or total(average of entire run)

SciGrow MODEL RUN

SciGrow version 2.3

Chemical: Fluopyram

Time is 6/23/2010 11:58:35

-------------------------------------------------------------------------------------------------------------

 Application Number of Total Use Koc Soil Aerobic

 Rate (lb/acre) Applications (lb/acre/yr) (ml/g)1 metabolism (days)2

-------------------------------------------------------------------------------------------------------------

 0.223 2.0 0.446 3.97E+02 294.5

-------------------------------------------------------------------------------------------------------------

Groundwater screening concentration (ppb) = 3.19E-01 = 0.319 ppb

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