UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

 OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION

MEMORANDUM Date: May 21, 2014

DP Barcode: D415627

PC Code 129081

SUBJECT: Drinking Water Exposure Assessment for the Section 3 New Use Registration 

of Sulfentrazone on Apples

TO: Barbara Madden, Risk Manager

Laura Nollen, Risk Manager Reviewer

Registration Division (7504P)

George Kramer, Chemist

Charles W. Smith III, Chief

Risk Assessment Branch 1

Health Effects Division (7509P)

FROM: Michael R. Barrett, Senior Chemist

Environmental Risk Branch V 

Environmental Fate and Effects Division (7507P)

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

Environmental Risk Branch V

Environmental Fate and Effects Division (7507P)

EFED has evaluated the proposed new use on apples and reassessed current uses for an updated 

assessment of drinking water exposure to the sulfentrazone residues of concern (parent + 3-

caboxylic acid sulfentrazone or 3CAS.) See Appendix A for chemical identities and structures

of sulfentrazone and 3CAS. This updated assessment also supports the registration review of 

sulfentrazone. The recommended values to be used in the drinking water exposure assessment 

are as follows:

 Acute exposure: 134 μg/L (ppb) – estimated in groundwater with PRZM-GW model
2

 Chronic exposure (for cancer risk): 98 μg/L – estimated in groundwater with PRZM-GW 

model

The highest surface water values (these were lower than for groundwater) modeled were:

 Acute exposure: 37.3 μg/L (ppb) – estimated in surface water with PRZM-EXAMS 

model

 Chronic exposure (for cancer risk): 8.3 μg/L – estimated in surface water with PRZMEXAMS model

The above values are the highest of all groundwater and surface water scenarios modeled and 

determined to appropriately represent the current and proposed uses of sulfentrazone herbicide. 

EFED used the PRZM/EXAMS model for surface water and the PRZM-GW and SCI-GROW 

models for groundwater. Additional details on the modeling procedures and results are provided 

below. 

The assessment incorporates some new methodology for the total residues of sulfentrazone

including the use of a new groundwater exposure model not available for previous assessments. 

The highest exposure estimates are from model estimates for groundwater sources; significant 

exposure potential from groundwater sources has also been shown by the results of four smallscale prospective groundwater monitoring studies.
Drinking Water Exposure Assessment for the Section 3 New Use 

Registration of Sulfentrazone on Apples

Table	of	Contents

Background..................................................................................................................................... 4

Current and Proposed Uses Summary ........................................................................................ 4

Analysis Plan .............................................................................................................................. 6

Environmental Fate of Sulfentrazone and Model Input.............................................................. 7

Sulfentrazone Monitoring Data................................................................................................. 11

Prospective Small-Scale Groundwater Studies..................................................................... 11

Other Surface and Ground Water Monitoring Data.............................................................. 14

Exposure Analysis ........................................................................................................................ 15

Modeling Results Summary...................................................................................................... 15

Comparison of Targeted Monitoring Data to Groundwater Modeling Results........................ 18

Appendix A: Identities and Chemical Structures for Sulfentrazone Residues of Concern .......... 20

Appendix B: Drinking Water Exposure Modeling Input and Output Details .............................. 22

Groundwater Modeling (PRZM-GW and SCI-GROW Models).............................................. 22

Surface Water Modeling (EXPRESS or PE5 Shell using PRZM-EXAMS)............................ 25

Estimated Drinking Water Concentrations by Scenario ....................................................... 25

Example EXPRESS Project (Input) File for PRZM-EXAMS.............................................. 28

Example PE5 PRZM-EXAMS Shell Input file and Output Summary................................. 35
4

Background

Current	and	Proposed	Uses	Summary

New uses have been requested for sulfentrazone on apples. A summary of current uses and the 

proposed use is provided in Table 1. The proposed use on apples carries the maximum single and 

annual application rates for all currently registered uses (0.375 lb ai/ A; other use sites with the 

same maximum rates are identified in Table 1.

Table 1. Application information for registered use sites and the apples proposed use of 

sulfentrazone.

Crop or 

NonAgricultural 

Use Si`te1

Single 

Min, lb 

ai/A 

product; 

All sites

Rates 

vary by 

soil 

texture / 

%O.M.?

Max # 

Applications.

Aerial 

application?

Minim. 

Interval 

(days)

PHI, 

days

Maxim. 

single 

(1st) 

applic., 

lb ai/A

Maxim. 

Annual 

Rate, 

lb ai/A

PROPOSED USE:

Apples 0.125 No 2* No 60 14 0.3750 0.3750

CURRENT USES:

Brassica leafy 

greens

0.070 Yes NS2 NS2 NS2 NS20.2000 0.2200

Corn (GMO 

tolerant to 

PPO herbic.)

0.094 Yes NS2 NS2 NS2 NS20.1875 0.3750

Corn (GMO 

tolerant to 

PPO herbic.)

0.141 Yes NS2 NS2 NS2 NS20.2500 0.3750

Cowpeas 

succu. (TN) 0.070 Yes NS2 NS2 NS2 NS2

0.1875 0.1875

Dry beans & 

peas (NO SD 

MT MN WY 

CO NE KS Wl 

Ml OR ID WA 

OR WIT)

0.070 Yes NS2 NS2 NS2 NS20.2500 0.2500

 

1

 Limitations to crop strains or certain geographical areas (states) are given in 

parenthesis.

2 NS: Not specified
Crop or 

NonAgricultural 

Use Si`te1

Single 

Min, lb 

ai/A 

product; 

All sites

Rates 

vary by 

soil 

texture / 

%O.M.?

Max # 

Applications.

Aerial 

application?

Minim. 

Interval 

(days)

PHI, 

days

Maxim. 

single 

(1st) 

applic., 

lb ai/A

Maxim. 

Annual 

Rate, 

lb ai/A

Fallow, 

Postharv. 

Burndown

0.094 Yes NS2 NS2 NS2 NS20.2500 0.2500

Horseradish 

((MN ND SD 

MT CO NE 

WY ID WA 

OR Wl Ml)

0.070 Yes NS2 NS2 NS2 NS20.2500 0.2500

Lima beans 

succul. (TN) 0.070 Yes NS2 NS2 NS2 NS2

0.1875 0.1875

Melons 0.250 No NS NS NS NS 0.2500 0.2500

Peanuts (AL, 

GA, MS, NC, 

SC, VA)

0.150 No NS NS NS NS 0.2500 0.3000

Potatoes 0.094 Yes NS Yes NS NS 0.2500 0.2500

Rhubarb 0.250 No 1.000 NS NA 46 0.2500 0.2500

Soybeans 0.141 No NS No NS NS 0.2484 0.2500

Succulent Peas 0.070 Yes NS No NS NS 0.1875 0.1875

Sunflower 

subgr. 20B 0.094 Yes NS Yes NS NS 0.2500 0.2500

Turnips 0.250 No 1.000 NS NA 3 0.2500 0.2500

Wheat - spring 

(ID, OR, WA) 0.188 No NS NS NS ca. 120 0.1875 0.1875

Apples 0.125 No 2* No 60 14 0.3750 0.3750

Asparagus 0.141 Yes NS NS NS 14 0.3750 0.3750

Berries 0.125 No 2 NS 60 3 0.3750 0.3750

Brassica h&s 

(Broccoli, 

Cabbage

0.070 Yes NS NS NS NS 0.3750 0.3750

Cabbage 

transplanted 

(MN ND SD 

MT CO NE 

WY ID WA 

OR Wl or Ml)

0.070 Yes NS NS NS NS 0.3750 0.3750

Citrus 0.125 No 2 NS 60 3 0.3750 0.3750
6

Crop or 

NonAgricultural 

Use Si`te1

Single 

Min, lb 

ai/A 

product; 

All sites

Rates 

vary by 

soil 

texture / 

%O.M.?

Max # 

Applications.

Aerial 

application?

Minim. 

Interval 

(days)

PHI, 

days

Maxim. 

single 

(1st) 

applic., 

lb ai/A

Maxim. 

Annual 

Rate, 

lb ai/A

Flax (ND SD 

MT MN WY 

CO NE KS)

0.070 Yes NS NS NS NS 0.3750 0.3750

Fruiting veg. 

& Okra 

(except 

cucurbits)

0.070 Yes NS NS NS NS 0.3750 0.3750

Grapes 0.125 No 2 NS 60 3 0.3750 0.3750

Mint 0.141 Yes NS NS NS NS 0.3750 0.3750

Railroad, 

Highway, 

Roadside, 

Pipeline and 

Utility Rightsof-Way, 

Industrial 

Areas, Fence 

Rows, and 

Other listed 

Non-crop Sites

0.250 No 1.000 Yes* NA NS 0.3750 0.3750

Soybeans 0.141 Yes NS Yes NS NS 0.3750 0.3750

Strawberry 0.070 Yes NS NS NS NS 0.3750 0.3750

Sugarcane 0.141 Yes NS Yes NS 120 0.3750 0.3750

Tobacco 0.141 Yes NS NS NS NS 0.3750 0.3750

Tree nuts 0.125 No 2 NS 60 3 0.3750 0.3750

Turf: Sod 

Production, 

lawns, golf 

fairways and 

roughs

0.125 No NS NS NS 90 for sod 0.3750 0.3750

NS=not specified

Analysis	Plan

For the current assessment, a complete update of the drinking water exposure assessment was 

undertaken to reflect new exposure modeling capabilities in EFED (especially PRZM-GW or 
7

Pesticide Root Zone Model which allows for Tier 2 and site-specific modeling of exposure from 

groundwater sources.) Additionally, this fully updated review of drinking water exposure 

supports the current Registration Review for sulfentrazone. The exposure models and versions 

used in this assessment include:

1. PRZM-GW version 1.07 (compiled 3/14/2014) for Tier 1 and Tier 2 groundwater 

modeling.

2. SCI-GROW (Screening Concentration In GROund Water) version 2.3; for Tier 1 

groundwater modeling

3. PRZM-EXAMS (Pesticide Root Zone Model – Exposure Analysis Modeling System) 

including PRZM version 3.12.2, compiled 5/12/2005 and EXAMS version 2.98.04.06 

compiled 4/25/2005.

More information on current EFED models is provided here:

pphttp://www.epa.gov/oppefed1/models/water/

Previous estimates of sulfentrazone residues in drinking water were done separately for parent 

and the 3-carboxylic acid sulfentrazone (3CAS) degradate. Sulfentrazone and its 3CAS 

degradate have a potential to reach both surface and ground-waters that may be used as drinking 

water sources. This review updates our assessment with more current models and has now taken 

a total toxic residues (TTR) approach to assessing exposure – this approach is adequate for the 

Health Effects Division assumption of equal toxicity of parent and degradate.

Environmental	Fate	of	Sulfentrazone	and	Model	Input

Sulfentrazone and its 3CAS degradate are highly persistent and mobile in the environment (for 

example, model input values for aerobic soil metabolism was a first order degradation half-life of 

875 days and a Koc value of 29 ml/g). A summary of sulfentrazone and the total toxic residues 

(TTR) or residues of concern (ROC)2environmental fate properties from the available studies 

and the corresponding drinking water exposure model input selection values is provided in Table 

2. 

Table 2. Physical/chemical Properties and Environmental Fate Properties of Sulfentrazone.

PARAMETER VALUE(S) SOURCE (Study 

Acceptability 

Classification)a

COMMENTS

 

2 Both terms are used interchangeably in this review to refer to the identity of the stressors included in this 

drinking water exposure assessment.
8

PARAMETER VALUE(S) SOURCE (Study 

Acceptability 

Classification)a

COMMENTS

Molecular Structure

Chemical Name (common) Sulfentrazone

CAS Number 122836-35-5

Name IUPAC Name: 2′,4′-Dichloro-5′-(4-difluoromethyl4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-

yl)methanesulfonanilide

CAS Name: N-[2,4-dichloro-5-[4-(difluoromethyl)-

4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-

yl]phenyl]methanesulfonamide

Chemical Class 

Mode of Action

Aryl triazinone.

Protoporphyrinogen oxidase (PPO) Inhibitor / 

Inhibits an enzyme of chlorophyll and heme 

biosynthesis.

https://ag.purdue.edu/btny/weeds

cience/Documents/47575_FINA

L_TakeAction_HerbicideClassC

hart.pdf

http://pnwhandbooks.org/weed/a

grichemicals/sulfentrazone

http://www1.agric.gov.ab.ca/$de

partment/deptdocs.nsf/all/prm64

87

Molecular Formula C11H10Cl2F2N4O3S -

Molecular Weight 387.2 Tomlin, C.D.S. (ed.). The 

Pesticide Manual - World 

Compendium, 11th ed. 

(1997)

Solubility 

in water, ppm (25 oC)

400 @ pH 7.0 Product Chemistry 

Submissions
9

PARAMETER VALUE(S) SOURCE (Study 

Acceptability 

Classification)a

COMMENTS

Vapor Pressure (25oC)

In mm Hg

9.75x10-10 Tomlin, C.D.S. (ed.). The 

Pesticide Manual - World 

Compendium, 11th ed., 

British Crop Protection 

Council, Surrey, England 

1997, p. 1126

Henry’s Law Constant, atmcu m/mole

(25 oC) 

6.37x10-13 Calculated Not volatile

Hydrolysis Half-life @ pH7

(25 oC)

(GL 835. 

143 days at pH 5, 

207-375 days at pH 7,

348 days at pH 9 

( 25 C)

41928202 (a) No major degradates over the 

30-day study. 

For DW modeling input, used 

375-day half-life for parent and 

no hydrolysis beyond the 3-

carboxylic acid degradate for the 

TTR.

Aqueous Photolysis 

Half-life (25 oC)

pH 5 = 0.50 days

pH 7 and 9 = 0.05 days

MRID 43345424, 

43588601 (a)

Not used for TTR modeling. See 

soil photolysis section.

Soil Photolysis 

Half-life (25 oC)

Sand soil = 98 days

Sandy loam soil = 161 days

3-hydroxymethyl metabolite 

reached a maximum of 3.9% of 

applied after 1 or 2 weeks 

(sampling continued for 33 days 

for both test soils.)

MRID 43345425 (a) Value used for TTRs assuming 

more limited exposure to 

sunlight of residues in drinking 

waters.

Aerobic Soil Metabolism 

Half-life (ASM) (T1/2)

T 1⁄2: 

1.) 545 days parent, 746 days 

TTR in sandy loam soil 

2.) 538 days parent, 622 days 

TTR in silty clay loam soil (25 

C) 

The major accumulating 

degradate was 3-carboxylic acid 

sulfentrazone which reached a 

maximum of 10.8%, but decline 

of parent was limited. 

Soil descriptions:

1.) WI (Saulk Co.) Thurston sandy 

loam soil (70% sand, 18% s i l t . 

12% clay. 1.6% O.M., pH 6.7, CEC 

5.8 meq/100 g

2.) IL (LaSalle Co.) silty clay loam 

soil (17% sand, 45% s i l t . 38% 

clay. 4.8% O.M., pH 6.4, CEC 26 

meq/100 g

MRIDs 41928203, 

42932117 (a)

For TTR, 90% Upper C.I. of 

mean t1/2 = 875 days.

For parent sulfentrazone, 90% 

Upper C.I. of mean t1/2 = 552.3

days (input for PE5)

Due to the high persistence of 

parent in these studies it is 

not possible to determine the 

ultimate extent of formation 

or the decline rates of the 

degradation products. 

Initially a 3-hydroxymethyl 

metabolite is formed which 

subsequently is further 

oxidized to a 3-carboxylic 

acid metabolite.

Anaerobic Soil Metabolism

Half-life (days)

Stable (but anaerobicity was not 

sufficiently documented

MRID 48958901 Study classified as supplemental 

but not a required study.
10

PARAMETER VALUE(S) SOURCE (Study 

Acceptability 

Classification)a

COMMENTS

Anaerobic Aquatic 

Metabolism

Half-life (days)

In a water: loamy sand sediment 

system = 3,283

MRID 43345426 (a) For aquatic exposure modeling 

(both parent and TTR) assumes 

that this input value is a zero rate 

(per EFED Guidance).

Aerobic Aquatic Metabolism

Half-life (days)

Study results not accepted at this 

time. More data are being 

requested.

Reported results (not cleared for 

use in exposure assessment):

679 SFO

Pond water: silty clay loam 

sediment (20oC, sediment pH 

6.1; 5.1% OM)

612 SFO

Canal water: sandy loam 

sediment system (20oC, sediment 

pH 6.0; 2.1% OM)

90% Upper C.I. of mean t1/2 = 

748.6 days (input for PE5)

MRID 48958902 (s) With no accepted data at this 

time, input (half-life) for PE5 is 

2x ASM. 

For model input use:

1,105 days for parent.

1,750 days for Total Toxic 

Residues (TTR)

Soil Partition Coefficient 

(Kd) (mL/g)

1. Jackson sandy loam, 3.8% 

OM, pH 6.9

2. Georgetown silt loam, 5.9% 

OM, pH 7.1

3. Troy Grove silty clay loam, 

3.9% OM, pH 7.0

4. Tavares sand, 0.4% OM, pH 

6.0

Respective Kf values:

0.55; 0.77; 0.77 and 0.15

Respective n values:

1.01; 1.03; 1.09; 0.98 

MRID 41911604 (Batch 

equilibrium soil 

Adsorption/Desorption 

study. (a)

See also 43355903 

(column leaching study)

Freundlich Kdes values were 

1.23-1.44 for the four soils. 

Not used for drinking water 

exposure model input.

Organic Carbon Partition

Coefficient (Koc) (mL/goc)

See Kd entry above for soil id.

Respective Kfoc values: 

29, 26, 40, 77

MRID 41911604. For PRZM modeling, chose Koc 

= 29 (median of the 3 non-sand 

soil values) for model input. Koc 

adequately accounts for 

adsorption. This value used for 

both parent and TTR modeling.

Log Octanol/water partition 

coefficient (Kow )(25◦C) 

Log Kow = 0.99 @ pH 7

Kow= 9.9

Terrestrial Field Dissipation 

Half-life

4 to 24 months at 4 sites. MRIDs 43651008, 

43651009, 43345434.

(a)

Leaching was further 

evaluated in four prospective 

groundwater monitoring 

studies – discussed in text of 

this document.
11

PARAMETER VALUE(S) SOURCE (Study 

Acceptability 

Classification)a

COMMENTS

Bioconcentration Factor 

(BCF) in fish

Negligible MRID 43345433 BCF study normally is not 

triggered when the Kow is <<< 

1000

pKa (acid dissociation 

constant)

6.56 Hatzios KK, ed; Herbicide 

Handbook of the Weed 

Science Society of 

America. 7th ed. Suppl. 

Champaign, IL: Weed Sci 

Soc Amer p. 67 (1998)

a

Study classification (a) = acceptable study ; (s) = supplemental study

Sulfentrazone	Monitoring	Data

The most relevant data available to support and characterize this drinking water exposure 

assessment are derived from four small-scale prospective groundwater monitoring studies that 

were submitted by the registrant to EPA; the monitoring results of these studies are summarized 

in Table 7. A brief summary of other available monitoring data is also provided below.

Prospective	Small-Scale	Groundwater	Studies

The small-scale prospective groundwater monitoring study is required for certain pesticides with 

high field leaching potential under the Office of Chemical Safety and Pollution Prevention 

(OSCPP) Guideline no. 835.7100. These studies provide detailed characterization of the amount 

of leaching and impacts on shallow unconfined aquifers of the pesticide and its degradates. The 

sites chosen for these studies overlie groundwater that is relatively vulnerable to contamination

and is capable of serving as source water for drinking. 

The registrant, FMC Corporation, has conducted prospective ground-water monitoring studies at 

four sites (described in Table 3, Table 4, Table 5, and Table 6). The first study conducted (the 

>95th %ile study) was not completed before it had to be terminated. Three additional studies 

were required based on the original registration at the time of sulfentrazone for soybeans. 

Selection of the three sites was to approximately represent the 75th, 85th, and 95th percentile 

vulnerability of ground water in the projected use area using currently available resources such 

as soil, hydrology, crop production, and weather data in conjunction with fate and transport 

models and general pesticide monitoring data. These sites are referred by the shorthand notation 

of the 75%, 85%, and 95% sites. A short description of the four study sites is provided in the 

tables below.
12

Table 3. Description of “95th percentile ” ground-water vulnerability site IN2. 

Soil Series: Tyner loamy sand. 

Family: Mixed.

Subgroup: Mesic Typic Udipsamments.

Characteristics at test site:

Surface layer typically 80% sand, 12% silt, and 8% clay with 1.0 to 1.7% o.m. Grades 

to a sand texture at 1 to 5 feet and below (up to 97% sand). Acidic (pH 4.7 to 7.0), 

becoming alkaline below 16 or 18 feet.

(DP Barcode D255967, no MRID assigned; 5/4/99 report, page 29f.)

Location1 Hanna, LaPorte County, Indiana.

Crop Soybeans

Pesticide 6/11/99: sulfentrazone @ 0.14 lbs ai/acre (the target application rate was 0.17 lbs 

ai/acre).

Tracer 6/11/99: 81.7 (100.5?) lbs bromide /acre (two different rates given, presumably 

representing actual confirmed and nominal application rates, respectively.)

Depth to ground water Average of 18 feet below ground surface.

Table 4. Description of “85th percentile ” ground-water vulnerability site IN1. 

Soil Series: Shipshe sandy loam.

Family: Loamy-skeletal, mixed.

Subgroup: Mesic Typic Argiudoll.

Characteristics at test site:

Surface layer sandy loam, 60% sand, 23% silt, and 17% clay with 3.2 to 4.8% 

organic matter. Grading to sand below about 3 feet. Acidic (pH 5.6 to 6.9), 

alkaline below about 3 feet, mean pH above 8 below 4 foot depth. (MRID 

447733-01, DP Barcode D254419, page 65).

Location Leesburg, Kosciusko County, Indiana.

Crop Soybeans

Pesticide 6/23/98: sulfentrazone @ 0.2 lbs ai/acre ; 6/14/99: sulfentrazone to one-half of 

field @ 0.2 lbs ai/acre.

Tracer 6/23/98: 105 lbs bromide/acre

Depth to ground water 27 to 33 feet
13

Table 5. Description of “75th percentile ” ground-water vulnerability site IN3. 

Soil Series: Coupee silt loam. 

Family: Mixed.

Subgroup: Mesic Ultic Hapludulfs.

Characteristics at test site:

Surface layer (up to about a 2-foot depth) typically loam to clay loam with 

approximately 25 to 50% sand, 25 to 45% silt, and 10 to 35% clay with, in the upper six 

inches 3.9 to 4.6% o.m., grading down to around 0.5% o.m. below 2 feet. Grades to a 

loamy sand texture from 2 to 6 feet and is predominantly sand below 6 feet (up to 97% 

sand). The soil is generally mildly acidic to occasionally mildly alkaline in the upper 

two feet (pH 5.1 to 7.5), the pH is variable in the same general range up to about a 14-

foot depth, and the remaining part of the vadose zone is alkaline from 14 to 30 feet 

below ground surface with a median pH of about 8.5 at the lower depths (DP Barcode 

D279430, MRID 453772-01; 3/16/01 report date, received 12/3/01; see page 72f for 

summary statistics of soil characteristics )

Location 2 miles south of the town of LaPorte, LaPorte County, Indiana.

Crop Soybeans

Pesticide 6/20/00: sulfentrazone @ 0.204 lbs ai/acre (the target application rate was 0.20 lbs 

ai/acre).

Tracer 6/20/00: 102 lbs bromide/acre (as 152 lbs KBr).

Depth to ground water Average of 21 feet below ground surface (original measurement, believed to represent 

seasonally high levels).

Table 6. . Description of “>95th percentile ” ground-water vulnerability site NC1. 

Soil Series: Tarboro loamy sand. 

Characteristics at test site:

Profile: >90% sand throughout the profile., Surface O.M. <1.5% and rapidly declining 

with depth.

Location Edgecombe County, North Carolina.

Crop Soybeans

Pesticide ~5/15/1992: sulfentrazone @ 0.5 lbs ai/acre.

Tracer 5/14/1992: 263 lbs bromide/acre (as 400 lbs KBr).

Depth to ground water From 6 to 10 feet below ground surface.

Maximum groundwater concentrations observed in each of the four studies are summarized in 

(Table 7). The four sites were selected by the registrant to be representative of >95

th (NC1 site), 

95th (IN1 site), 85th (IN2 site), and 75th (IN3 site) percentile groundwater vulnerability in likely 

sulfentrazone use areas at the time of the studies. The results indicate that sulfentrazone or the 
14

acid degradate SCA may eventually leach to groundwater at a wide variety of sites where it is 

used. Whether parent sulfentrazone or SCA are the dominant moiety found in groundwater over 

the long-term will likely depend on the relative resistance to hydrolysis of sulfentrazone in the 

vadose zone and in groundwater from site to site. Long-term observed concentrations may be 

higher than those observed if sulfentrazone continues to be used at a site over multiple years.

Table 7. Maximum observed concentrations of sulfentrazone and its acid degradate in shallow groundwater below or 

immediately downgradient of treated fields at four sites.

Chemical NC1 

Site

IN1 

Site

IN2

Site

IN3 

Site

Concentration in ppb (days after initial applicat. of obs.)

Sulfentrazone 37.4

(160d)

0.86 

(577d)

0.11

(153d)

0.26

(634d)

3-Carboxylic Acid Sulfentrazone 11.4

(160d)

2.50 

(455d)

<5

(variable)

1.61

(1499d)

SITE DESCRIPTIONS:

NC1 (>95

th site ) = The test site was located near the town of Tarboro in Edgecombe County, North Carolina, and 

was located in a setting classified as very high vulnerability to groundwater contamination. Soil series = Tarboro 

sand to loamy sand. Sulfentrazone application rate = 0.50 lb ai/acre. (MRID 43345434 and 43926814). Average 

depth to groundwater = 9.2 feet. 

IN1(95th site) = The test site was located near the town of Leesburg in Kosciusko County, Indiana, and was located 

in a setting classified as 85th percentile in terms of vulnerability to groundwater contamination. Soil series = Tyner 

loamy sand to sandy loam. Sulfentrazone application rate = 0.17 lb ai/acre. Average depth to groundwater = 18.9 

feet. (MRID 46816001). 

IN2 (85th site = The test site was located near the town of Hanna in LaPorte County, Indiana, and was located in a 

setting classified as 95th percentile in terms of vulnerability to groundwater contamination. Soil series = Shipshe 

loamy sand to sandy loam. Sulfentrazone application rate = 0.22 to 0.44 lb ai/acre. Average depth to groundwater = 

30 feet. (MRID 47453601).

IN3 (75th site) = The test site was located near the town of La Porte in LaPorte County, Indiana, and was located in 

a setting classified as 75th percentile in terms of vulnerability to groundwater contamination. Soil series = Coupee 

silt loam. Sulfentrazone application rate = 0.22 lb ai/acre. Average depth to groundwater = 21 feet. (MRID 

47453602).

Other	Surface	and	Ground	Water	Monitoring	Data

Surface and ground water data from other available pesticide monitoring programs were 

reviewed to provide additional context concerning the potential presence of sulfentrazone in 

ambient water resources. In most major monitoring programs for pesticides in surface and 
15

ground waters sulfentrazone has not been included in the list of analytes. No significant 

detections were located in any of the following sources:

These water monitoring programs do not target sample collection to peak use locations or 

application times for particular pesticides, nor do they target sample collection to high 

precipitation events (i.e., high-runoff events) or areas highly vulnerable to groundwater 

contamination. Additionally, the sampling frequency in these monitoring programs was not 

designed to capture peak concentrations. Therefore, the monitoring data reported by these 

programs may not represent the highest concentrations in ambient surface water, and are 

considered qualitative information for the purposes of this ecological risk assessment. The 

groundwater monitoring sites also were not selected based upon sulfentrazone use.

U.S. Geological Survey National Water Quality Assessment program – data query at:

http://cida.usgs.gov/nawqa_queries_public/

(only 2 groundwater sample results retrieved, neither had a quantified detection. Sulfentrazone 

has only recently been added to the analytical schedule for the USGS multi-residue monitoring 

used in NAWQA and similar monitoring programs. )

U.S. Geological Survey surface water mid-continent herbicide monitoring program:

http://co.water.usgs.gov/midconherb/html/sulfonylurea.html).

(sulfentrazone apparently not analyzed for).

USDA Pesticide Data Program (PDP) Data - The PDP drinking water monitoring project 

provides non-targeted pesticide occurrence data in raw, finished (treated/tap), and groundwater 

for selected community water systems in the United States. Sulfentrazone has not been reported 

in surface water or groundwater monitoring data from 2003 to 2012 but it appears to not have 

been monitored for. PDP data are available at http://www.ams.usda.gov/AMSv1.0/pdp.

CDPR. 2013. Sampling for Pesticide Residues in California Well Water. 2012 Update. California 

Environmental Protection Agency, Department of Pesticide Regulation. 262 pp. Sacramento, 

CA. Available at: www.cdpr.ca.gov/docs/emon/pubs/ehapreps/eh0801.pdf

Sulfentrazone residues were not reported in any of the ground water samples.

Exposure	Analysis

Modeling	Results	Summary

Table 8 (groundwater EDWCs) and Table 9 (surface water EDWCs) summarize the results from 

scenarios with higher exposure estimation for the 3 exposure models used: 

1. Groundwater exposure with PRZM-GW (for the 3 of the 6 standard scenarios 

determined to well-represent labeled and proposed uses for sulfentrazone.)

2. Groundwater exposure with SCI-GROW (no site-specific scenario, provides a single 
16

screening value.)

3. Surface water with PRZM-EXAMS “index” reservoir (for the 3 scenario / input 

combinations that yielded the highest acute and/or chronic exposure estimates)

Complete modeling results for all of the scenarios can be found in Appendix B: Drinking Water 

Exposure Modeling Input and Output . 

The highest exposure values were determined with PRZM-GW scenarios that were determined 

to represent possible exposure from uses allowed on the product labels. Note that for the 

PRZM-GW three of the six scenario results were, after examination of the sulfentrazone 

product labels, determined to not be representative of sulfentrazone uses allowed on the label. 

For example, the label does not allow use on any sand texture soils with organic matter content 

< 1%. The label also does not allow use on cotton and the modeling results from a scenario 

based on the cotton use also were not used. EFED has used, however, one scenario with slightly 

less than 1% organic matter (the Delmarva scenario) since it does seem to represent well areas 

where sulfentrazone may be used and there is not likely to be much difference in EDWCs from a 

soil with 0.9% O.M. compared to 1.0% O.M.

Table 8. PRZM-GW and SCI-GROW estimates of sulfentrazone in groundwater [μg/L].

Groundwater

Scenario

Application 

Date Relative 

to Emergence

Topsoil % 

OM

Topsoil 

Textural 

Class 

(% 

sand)

Highest 

daily 

value 

Post 

Breakthrough 

Average 

Avg 

Breakthrough 

Time

(days)

Scenarios Representing Labeled Uses for Sulfentrazone

Delmarva

Sw. corn +10 0.89 Sand(92%) 98.0 81.0 1417

FL Potato +10 7.21 Sand 

(93%) 62.1 55.8 1174

GA Coastal 

Plain

Peanut

+10 1.29 Sandy

loam

(66%) 40.4 35.0 1693

SCI-GROW 2.3 Tier I

1

SCI-GROW 

Tier 1

NA Variable Usually

sand or 

lm. Sa. 57.5 57.5 NA

Scenarios which Represent Sites for which the Label does not Permit Application2

FL Central 

Ridge

Citrus

+10 0.25 Sand

(96%)

92.4 85.1 1007
17

Groundwater

Scenario

Application 

Date Relative 

to Emergence

Topsoil % 

OM

Topsoil 

Textural 

Class 

(% 

sand)

Highest 

daily 

value 

Post 

Breakthrough 

Average 

Avg 

Breakthrough 

Time

(days)

NC Coastal 

Plain

Cotton

+10 1.05 Loamy 

sand

(76%) 117.0 92.7 2221

WI Central 

Sands

Corn

+10 0.79 Sand

(95%)

112.0 85.8 2760

NA = not available.

1

SCI-GROW is a regression model based upon observations at multiple sites with highly permeable 

(usually sand or loamy sand) soils and shallow unconfined aquifers with the water table about 10 to 25 

feet below the surface. This is similar to most of the PRZM-GW standard scenarios.

2

Reasons for rejection:

FL Citrus = Use not allowed on soil type.

NC Cotton = Site best represents crop not used on.

WI Corn = Use not allowed on soil type. 

Table 9. PRZM/EXAMS estimated surface water EDWCs for sulfentrazone (with PCAa,3).

Scenario 

State

Crop Basis 

of Scenario

App. Date 

rel. to 

Planting

1-in-10 year

30-year 

ave

peak 10 yr 

average

[μg/L]

Top Ten Scenario Based EDWCs for Acute Exposure

FL Sugarcane 40 37.3 3.2 1.6

FL Peppers 40 34.9 4.8 2.8

MS Sugarcane 40 32.7 4.7 2.5

LA Corn -1 31.3 5.3 1.8

FL Sugarcane -1 28.0 3.5 1.7

FL Peppers -1 22.7 3.1 1.2

FL Cucumber -1 19.8 2.4 1.6

 

3

Echeverria et al., 2012. Guidance on Development Use of Percent Cropped Area and 

Percent Turf Area Adjustment Factors in Drinking Water Exposure Assessments:2012 Update 

http://www.epa.gov/oppefed1/models/water/pca_adjustment_dwa.html
18

Scenario 

State

Crop Basis 

of Scenario

App. Date 

rel. to 

Planting

1-in-10 year

30-year 

ave

peak 10 yr 

average

[μg/L]

FL Strawberry 40 16.7 2.5 1.6

PA Citrus -1 16.5 3.0 1.4

FL Tomato 40 15.2 3.1 1.5

Top Ten Scenario Based EDWCs for Chronic Exposure

CA Citrus -1 13.4 11.9 8.3

CA Grapes -1 12.1 10.2 7.7

MI Asparagus -1 10.6 9.1 7.5

CA Tomato -1 11.5 8.1 5.0

OR Xmas Trees -1 7.7 5.8 4.2

FL Turf -1 6.4 4.8 4.1

PA Turf -1 6.0 4.6 4.1

ND Canola -1 7.1 5.0 3.5

NY Grapes -1 6.8 4.1 3.0

OR Grass seed -1 6.6 4.3 3.1

a

PCA (Percent Crop Area) = 0.95 turf and all agricultural land combination

b A is aerial spray and G is ground spray

c Application date Month-Day

Further refinement may be possible for the estimates which could potentially lead to lower 

groundwater exposure estimates, possibly significantly closer to previous estimates. For 

example, sulfentrazone monitoring data exist from four PGW studies at sites that with the 

intrinsic groundwater vulnerability in the moderately to high range (A vulnerability analysis was 

part of the site selection for these studies.)

Comparison	of	Targeted	Monitoring	Data	to	Groundwater	Modeling	

Results

Since the highest model estimates were for groundwater a closer comparison was made of the 

targeted and well-characterized monitoring data from the four small-scale prospective 

groundwater monitoring (PGW) studies to the PRZM-GW groundwater model results. The actual 

application rates associated with the observed concentrations in the PGW studies were adjusted 

for the maximum label rates according to the soil characteristics of the PGW site (i.e. label rates 

are varied by soil type for crops with the higher rates – see “site specific maximum rate” in Table 
19

10). The result of these adjustments were that the highest observed concentration of the TTR at a 

maximum label rate is calculated to be 18.3 ug/L which is several times less than the modeled 

maximum concentration. One possible major reason for the difference between the PRZM-GW

values and the observed concentrations is that PRZM-GW is being run with standard Tier I 

assumptions of application every year at the maximum permitted rate for 30 or more consecutive 

years. An impact of this assumption for persistent compounds, particularly those with no 

hydrolysis, is that the pesticide concentration in the aquifer may increase from several years of 

application before a sort of equilibrium concentration is reached (due to the slow flow through in 

the aquifer). Should refinement be needed of the drinking water exposure numbers further efforts 

should focus on matching PRZM-GW simulation inputs to the PGW data and then adjusting 

PRZM-GW inputs for sulfentrazone TTR simulations in a scientifically justifiable way to 

provide more certain exposure predictions.

Table 10. Maximum observed concentrations of sulfentrazone and its acid degradate at four sites 

(adjusted to represent a site specific maximum rate as specified on product labels).

Chemical

NC1 

>95%ile1

Site

IN1

95%ile

Site

IN2

85%ile

Site

IN3

75%ile

Site

Concentration in ppb (days after initial applic. of obs.)

Sulfentrazone 14.03 NA 0.16 0.44

3-Carboxylic Acid Sulfentrazone 4.28 NA 5.38 2.74

Total Toxic Residues (parent + 3CAS)1

18.30 NA 5.54 3.19

Actual application rate 0.50 0.17 0.22 0.22

Site specific maximum rate on label 0.19 NA 0.32 0.38

1 Refers to the vulnerability ranking of the registrant for the site based on a survey of soybean production 

soils. See earlier text for site descriptions.

2 Actual ug/L. Molecular weights of parent and 3CAS are 387.1 and 417.18, respectively.

NA – Not applicable since the IN1 site does not meet current label criteria for applications of products containing 

sulfentrazone.
20

Appendix	A:	Identities	and	Chemical	Structures	for	

Sulfentrazone	Residues	of	Concern

Sulfentrazone 

Full Chemical Names

IUPAC: 2′,4′-Dichloro-5′-(4-difluoromethyl-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-

yl)methanesulfonanilide

CAS: N-[2,4-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-

yl]phenyl]methanesulfonamide

CAS No.: 122836-35-5

Formula: C11H10Cl2F2N4O3S

MW: 387.1 g/mol

SMILES: CLc1cc(CL)c(NS(=O)(=O)C)cc1N2N=C(C)N(C(F)F)C2(=O)
21

Sulfentrazone 3-carboxylic acid (SCA)

IUPAC: 1-(2,4-Dichloro-5-(N-(methylsulfonyl)amino)-pheny]-4-difluoromethyl-4,5-dihydro-5-

oxo-1H-1,2,4-triazol-3-carboxylic acid

CAS: N-[2,4-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-5-oxo-1H-1,2,4-triazol-1-

yl]phenyl]methanesulfonamido-3-carboxylic acid

CAS No.: 134391-01-08

Formula: C11H8Cl2F2N4O5S

MW: 417.18 g/mol

SMILES: CS(=O)(=O)Nc1cc(c(cc1Cl)Cl)n2c(=O)n(c(n2)C(=O)O)C(F)F
22

Appendix B:	Drinking	Water	Exposure	Modeling	Input	and	

Output	Details

Groundwater	Modeling	(PRZM-GW	and	SCI-GROW	Models)

PRZM-GW Sample PGI (input) File

Sulfetraz TTR

0

746

True

29

1

1

,,,,,,,,,,,,,,,,,,,,,,,,,

,,,,,,,,,,,,,,,,,,,,,,,,,

0.42,,,,,,,,,,,,,,,,,,,,,,,,,

1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,

10,,,,,,,,,,,,,,,,,,,,,,,,,

False

1

last

0.0,0.0,0.0

,,,,,,,,,,,,,,,,,,,,,,,,,

future expansion

future expansion

future expansion

future expansion

future expansion

future expansion

future expansion

Wisconsin Corn - WI Central Sands

C:\Models\Inputs\Metfiles\w14920.dvf

0.76

0.36

18

90,100

100

0.25

01

05
23

21

07

20

10

1

2

0.1

0.9

4.0

9

1.63,1.63,1.68,1.68,1.59,1.59,1.59,1.59

0.24,0.24,0.22,0.22,0.23,0.23,0.23

0.034,0.034,0.025,0.025,0.016,0.016,0.016

0.46,0.46,0.14,0.09,0.09,0.08,0.07,0.07

True

95,95,96,96,97,97,97,97

2.3,2.3,2.5,2.5,1.7,1.7,1.7,1.7

5.6

0.2

50

1

PRZMGW-Inp File_Sulfetraz TTR; Corn-WI Central Sands.txt

Figure 1. PRZM-GW input file for the WI central sands (based on corn) scenario.

PRZM-GW Model Output

Scenario I

D

Crop Basis Peak(ppb

)

PBT 

Avg(ppb

)

SimAv

g

BrkThru(

d)

Throughput

s

90-

day 

Avg

.

DELMARVA_STD.SC

N

Sweet 

Corn

134 98 81 1416.943 7.734959 134

FLCITRUS_STD.SCN Citrus 118 92.4 85.1 1007.226 10.88137 117

FLPOTATO_STD.SCN Potato 79.6 62.1 55.8 1174.253 9.333593 79.

5

GACOASTAL_STD.SC

N

Peanuts 50.8 40.4 35 1693.468 6.471926 50.

8

NCCOASTAL_STD.SC Cotton 173 117 92.7 2220.823 4.935106 173
24

N

WISANDS_STD.SCN Corn 130 112 85.8 2759.691 3.971459 130

Sulfentrz-TTR 6StdScenarios_CAM1_batc1 WISANDS_STD0.zts

Figure 2. Daily time series output file for PRZM-GW Wisconsin corn / central sands scenario.

Figure 3. FL (Central Ridge) Citrus Scenario – sulfentrazone TTR time series.

Figure 4. NC Coastal Cotton Scenario – sulfentrazone TTR time series.
25

SCIGROW Modeling Input and Results

 

 SCIGROW 

 VERSION 2.2: NOVEMBER 1, 2001 

 RUN No. 1 FOR SULFENTRAZONE ** INPUT VALUES ** 

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

 APP RATE APPS/ TOTAL/ SOIL AEROBIC SOIL METAB 

 (LBS/AC) YEAR SEASON KOC HALFLIFE (DAYS) 

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

 .375 1 .375 43.0 545.00

 GROUND-WATER SCREENING CONCENTRATION (IN UG/L - PPB) 

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

 15.701670

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

Surface	Water	Modeling	(EXPRESS	or PE5	Shell	using	PRZM-EXAMS)

Estimated	Drinking	Water	Concentrations	by	Scenario

The results for each scenario / application modeled are presented in Table 13 and 14 as generated 

by the EXPRESS modeling shell. Note that these reflect PCA factors that were later adjusted 

upward to reflect all allowed use sites. The PCA values in this table were:

46% for corn

41% for soybeans

87% for all other crops

Table 11. Estimated drinking water concentrations in index reservoir, applications made 

one day prior to planting.

State

Scenar 

Crop ExpMedia 1-Day 4-Day 21 Day 60 Day 90 Day Yearly

LA Sgc Limnetic 27.971 26.961 24.264 18.096 4.563 2.025
26

FL Sgc Limnetic 26.961 22.959 19.523 13.911 3.322 1.638

FL Pep Limnetic 21.811 20.958 18.331 13.389 2.996 1.182

FL Cuc Limnetic 19.053 18.296 15.851 11.471 2.351 1.539

MS Cor Limnetic 15.898 15.410 13.478 10.175 2.699 0.905

FL Cit Limnetic 15.851 13.311 11.910 9.309 2.842 1.370

FL Str Limnetic 13.885 13.546 12.110 9.492 2.485 1.164

CA Cit Limnetic 12.928 12.928 12.920 12.754 11.623 8.325

CA Gra Limnetic 11.658 11.658 11.571 11.397 9.788 7.393

CA Tma Limnetic 11.032 11.023 10.849 10.501 7.747 4.807

FL Cbb Limnetic 10.501 10.249 9.292 7.561 2.430 1.199

MI Asp Limnetic 10.162 10.162 10.075 9.901 8.787 7.246

MI Bea Limnetic 9.755 9.592 9.243 8.517 3.852 2.447

GA Pcn Limnetic 8.643 8.427 7.634 6.112 1.944 0.936

PA Tma Limnetic 8.499 8.406 8.008 7.126 3.332 1.626

NC Tba Limnetic 8.477 8.395 8.100 7.457 4.865 2.074

ME Pot Limnetic 7.800 7.713 7.435 6.742 3.479 2.264

OR Xma Limnetic 7.417 7.392 7.282 7.059 5.577 4.024

CA Wal Limnetic 6.993 6.947 6.739 6.274 3.848 2.447

NC Pnt Limnetic 6.909 6.853 6.522 6.167 2.733 1.690

ND Cno Limnetic 6.819 6.785 6.671 6.409 4.808 3.411

NY Gra Limnetic 6.495 6.460 6.321 6.040 3.901 2.900

KS Srg Limnetic 6.447 6.386 6.044 5.355 2.924 1.599

PA App Limnetic 6.408 6.365 6.150 5.679 3.311 1.410

FL Tma Limnetic 6.116 5.888 5.045 3.677 0.967 0.624

OR Gra Limnetic 6.033 5.999 5.884 5.619 3.901 2.864

FL Tur Limnetic 5.821 5.804 5.726 5.552 4.383 3.767

PA Tur Limnetic 5.485 5.467 5.398 5.282 4.225 3.729

IL Cor Limnetic 5.438 5.352 5.083 4.441 1.794 1.018

NC App Limnetic 5.091 5.025 4.784 4.287 2.242 1.138

OR Fil Limnetic 5.077 5.035 4.856 4.494 2.592 1.878

OH Cor Limnetic 4.758 4.713 4.490 4.016 1.729 0.744

NC Cor Limnetic 4.667 4.578 4.324 3.798 1.597 0.645

OR App Limnetic 4.371 4.337 4.193 3.897 2.564 1.033

MS Syb Limnetic 4.319 4.237 3.843 3.101 0.955 0.560

OR Min Limnetic 3.594 3.568 3.456 3.223 2.030 1.739

ND Whe Limnetic 3.496 3.474 3.393 3.222 2.038 1.432

PA Cor Limnetic 2.838 2.806 2.695 2.427 1.401 0.718

ID Pot Limnetic 2.714 2.704 2.674 2.571 1.876 1.634

Maximum: 27.971 26.961 24.264 18.096 11.623 8.325
27

Table 12. Estimated drinking water concentrations in index reservoir, applications made 

40 days prior to planting.

State

Scenar 

Crop ExpMedia 1-Day 4-Day 21 Day 60 Day 90 Day Yearly

FL Pep- Limnetic 37.253 35.679 19.018 13.755 3.035 1.491

FL Sgc- Limnetic 33.573 31.120 24.986 19.392 4.635 2.707

LA Sgc- Limnetic 31.416 29.162 22.272 14.581 4.550 2.370

FL Str- Limnetic 16.060 15.016 12.389 7.579 2.444 1.564

PA Tma- Limnetic 14.572 14.024 13.207 9.996 2.969 1.464

FL Cuc- Limnetic 14.494 14.198 12.171 7.554 2.452 1.088

FL Cit- Limnetic 13.354 12.693 11.240 9.344 2.660 1.499

FL Tma- Limnetic 13.102 12.667 10.005 7.803 1.737 0.996

ME Pot- Limnetic 12.702 12.354 11.293 9.347 3.371 1.938

PA App- Limnetic 12.023 11.684 10.988 9.709 3.409 1.322

NC App- Limnetic 11.145 10.579 8.600 7.076 2.226 1.038

KS Srg- Limnetic 10.799 10.623 10.074 7.954 2.549 1.192

ND Cno- Limnetic 9.405 9.118 8.478 6.582 3.030 1.605

GA Pcn- Limnetic 8.857 8.511 7.473 4.211 1.135 0.749

MI Bea- Limnetic 8.732 8.553 7.983 7.048 3.118 1.858

FL Cbb- Limnetic 8.312 8.035 7.274 5.002 1.874 1.134

NY Gra- Limnetic 6.775 6.602 6.047 5.271 2.383 1.638

MS Cor- Limnetic 6.504 6.067 5.437 4.341 1.237 0.626

CA Cit- Limnetic 6.418 6.326 5.942 5.296 2.389 1.135

OR Xma- Limnetic 5.457 5.364 5.025 4.503 2.233 1.328

NC Pnt- Limnetic 5.207 5.116 4.670 4.240 1.692 0.980

PA Cor- Limnetic 5.193 5.009 4.692 4.224 1.388 0.601

CA Tma- Limnetic 5.039 4.947 4.726 4.171 1.746 1.097

OR Gra- Limnetic 4.807 4.695 4.262 3.520 1.630 0.976

MS Syb- Limnetic 4.498 4.297 3.860 3.342 1.043 0.435

NC Tba- Limnetic 4.466 4.394 4.137 3.464 1.328 0.918

FL Tur- Limnetic 4.322 4.269 3.978 3.443 1.346 0.922

IL Cor- Limnetic 4.286 4.176 3.870 3.262 1.222 0.642

ND Whe- Limnetic 4.054 3.950 3.567 2.877 1.519 1.086

CA Wal- Limnetic 3.978 3.917 3.654 3.182 1.362 0.964

CA Gra- Limnetic 3.828 3.768 3.547 3.121 1.411 1.011

OR Fil- Limnetic 3.655 3.611 3.477 3.176 1.485 1.109

PA Tur- Limnetic 3.611 3.569 3.369 3.030 1.555 1.133

OH Cor- Limnetic 3.502 3.427 2.731 2.158 0.790 0.522
28

NC Cor- Limnetic 3.311 3.207 2.916 2.472 0.904 0.495

OR App- Limnetic 2.856 2.831 2.706 2.430 1.028 0.526

MI Asp- Limnetic 2.854 2.818 2.669 2.366 1.443 1.266

OR Min- Limnetic 2.723 2.689 2.545 2.257 1.136 0.894

ID Pot- Limnetic 1.986 1.960 1.860 1.621 0.743 0.609

Maximum: 37.253 35.679 24.986 19.392 4.635 2.707

Example	EXPRESS	Project	(Input)	File for	PRZM-EXAMS

Master Project File Created: 2014-04-11 at 16:36:30

Express v. 1.03.02 (2007-07-20) 

Parent Compound: Sulfentrazone TTR 

 Scenario Group File: 0 No GroupFile

 Scenario Type: 3

 PRZM Crop Selector: 00000000000001000100110010000001000000010000100011

 PRZM Crop Selector: 

10000001000110000110000000000011010101000000100000

 PRZM Crop Selector: 

00010011010100000000000100000100000010001100000000

 PRZM Crop Selector: 

00101010111000001000000000000000000000000000000000

Chemical Input Data Controls: 1 1 0 1 0

 Express Operational Mode: OPP

Chemical Name(s): Sulfentrazone TTR | 

 Molecular Weight: 387.2 

 Plant Uptake Factor: 0.000 

Partition Coefficient Method: 1 1

Partition Coefficient Value: 29.00 29.00 

 Vapor Pressure: 0.9750E-09

 Solubility : 400.0 

 Soil Degradation Half-Life: 875.0 

 % Degradate formed: 80.00 0.000 0.000 

 Foliar Half-Life: 0.000 

 Foliar Washoff Coefficient: 0.5000 

 Air Diffusion Coefficient: 4300. 

 Enthalpy of Vaporization: 20.00 

Application DataSets Number: 39

 Application Parameters: 1 1 2 2 1 0 0 91.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 2 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0
29

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 1.000 

 Drift Index Reservoir % : 6.400 

 Efficiency % : 99.00 

 Application Parameters: 1 2 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 1.000 

 Drift Index Reservoir % : 6.400 

 Efficiency % : 99.00 

 Application Parameters: 1 2 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 1.000 

 Drift Index Reservoir % : 6.400 

 Efficiency % : 99.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.2500 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2
30

 Depi (cm) : 4.000 

 Rate : 0.2500 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 46.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.2500 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 46.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.2500 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 46.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 
31

 Rate : 0.2500 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 46.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.2500 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 46.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.2500 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 
32

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 2 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1 30

 Month : 0 0

 CAM : 2 2

 Depi (cm) : 4.000 4.000 

 Rate : 0.1500 0.1500 

 Drift Farm Pond % : 5.000 5.000 

 Drift Index Reservoir % : 16.00 16.00 

 Efficiency % : 95.00 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.2500 

 Drift Farm Pond % : 5.000 
33

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.2500 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 41.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.2500 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 
34

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Application Parameters: 1 1 2 2 1 0 0 87.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 
35

 Application Parameters: 1 1 2 2 1 0 0 56.00 0

 Days Relative/Absolute : - 1

 Month : 0

 CAM : 2

 Depi (cm) : 4.000 

 Rate : 0.1875 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 

 Efficiency % : 95.00 

 Product chem./hydr. status: 1 1 1

Aerobic Dissipation (days) : 1750. 

 Q10 Base Temperature : 25.00 

 Q10 Limnetic : 2.000 

Anaerobic Dissipation(days): 0.000 

 Q10 Base temperature: 25.00 

 Q10 Benthic : 2.000 

Photolysis Half-Life (days): 98.00 

 Number of Hydrolysis Obs.: 3

 Hydrolysis Temperatures: 25.00 

 Hydrolysis C1: 0.000E+00 0.000E+00 0.000E+00

 pH Hydrol. C1: 5.00 7.00 9.00

 Melting Point: -99.00 

Example	PE5	PRZM-EXAMS	Shell	Input	file	and	Output	Summary

stored as LA-Sgc_SlfnAer1pht98.out

Chemical: Sulfentrazone TTR

PRZM environment: LAsugarcaneSTD.txt modified Tueday, 29 May 2007 at 

13:56:00

EXAMS environment: ir298.exv modified Thuday, 29 August 2002 at 

16:34:12

Metfile: w13970.dvf modified Wedday, 3 July 2002 at 10:05:36

Water segment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 20.67 19.97 17.4 12.29 8.345 2.058

1962 8.707 8.402 7.255 5.341 4.336 2.198

1963 14.42 13.91 12.47 9.568 6.544 2.262

1964 12.85 12.41 10.99 6.911 4.866 2.146

1965 18.3 17.64 15.19 11.14 7.599 2.907

1966 11.87 11.45 9.858 8.587 6.959 2.877

1967 7.74 7.464 6.431 5.437 4.563 1.799

1968 6.602 6.419 6.043 4.497 3.164 1.406

1969 9.258 8.929 8.039 3.931 2.808 1.197

1970 23.33 22.5 20.41 15.78 12.33 4.01

1971 10.32 9.954 8.568 7.599 6.327 2.557

1972 20.73 19.98 18.09 13.69 10.14 3.342

1973 15.07 14.53 12.68 9.33 7.15 2.771

1974 5.452 5.261 4.544 3.999 3.216 1.64
36

1975 3.435 3.313 2.943 1.954 1.595 0.7309

1976 17.08 16.47 14.63 11.66 8.209 2.36

1977 14.77 14.24 12.9 9.996 7.033 2.746

1978 17.28 16.66 14.58 8.218 5.65 2.301

1979 9.907 9.554 8.806 6.937 5.104 2.671

1980 57.66 55.6 48.27 35.69 26.79 7.205

1981 15.33 14.8 12.8 9.461 7.701 2.78

1982 10.85 10.56 9.123 5.089 3.56 1.193

1983 6.485 6.256 5.398 3.967 3.346 1.82

1984 38.29 37.25 33.4 25.36 19.64 5.214

1985 18.97 18.44 16.81 12.75 9.94 4.136

1986 34.81 33.57 29.23 21.72 16.87 4.951

1987 13.7 13.21 11.4 8.712 6.445 2.914

1988 7.235 6.977 6.493 5.444 4.08 1.943

1989 15.64 15.15 13.13 11.62 9.001 2.867

1990 25.71 24.79 21.49 16.51 12.26 3.934

Sorted results

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

0.032258064516129 57.66 55.6 48.27 35.69 26.79 7.205

0.0645161290322581 38.29 37.25 33.4 25.36 19.64 5.214

0.0967741935483871 34.81 33.57 29.23 21.72 16.87 4.951

0.129032258064516 25.71 24.79 21.49 16.51 12.33 4.136

0.161290322580645 23.33 22.5 20.41 15.78 12.26 4.01

0.193548387096774 20.73 19.98 18.09 13.69 10.14 3.934

0.225806451612903 20.67 19.97 17.4 12.75 9.94 3.342

0.258064516129032 18.97 18.44 16.81 12.29 9.001 2.914

0.290322580645161 18.3 17.64 15.19 11.66 8.345 2.907

0.32258064516129 17.28 16.66 14.63 11.62 8.209 2.877

0.354838709677419 17.08 16.47 14.58 11.14 7.701 2.867

0.387096774193548 15.64 15.15 13.13 9.996 7.599 2.78

0.419354838709677 15.33 14.8 12.9 9.568 7.15 2.771

0.451612903225806 15.07 14.53 12.8 9.461 7.033 2.746

0.483870967741936 14.77 14.24 12.68 9.33 6.959 2.671

0.516129032258065 14.42 13.91 12.47 8.712 6.544 2.557

0.548387096774194 13.7 13.21 11.4 8.587 6.445 2.36

0.580645161290323 12.85 12.41 10.99 8.218 6.327 2.301

0.612903225806452 11.87 11.45 9.858 7.599 5.65 2.262

0.645161290322581 10.85 10.56 9.123 6.937 5.104 2.198

0.67741935483871 10.32 9.954 8.806 6.911 4.866 2.146

0.709677419354839 9.907 9.554 8.568 5.444 4.563 2.058

0.741935483870968 9.258 8.929 8.039 5.437 4.336 1.943

0.774193548387097 8.707 8.402 7.255 5.341 4.08 1.82

0.806451612903226 7.74 7.464 6.493 5.089 3.56 1.799

0.838709677419355 7.235 6.977 6.431 4.497 3.346 1.64

0.870967741935484 6.602 6.419 6.043 3.999 3.216 1.406

0.903225806451613 6.485 6.256 5.398 3.967 3.164 1.197

0.935483870967742 5.452 5.261 4.544 3.931 2.808 1.193

0.967741935483871 3.435 3.313 2.943 1.954 1.595 0.7309
37

0.1 33.9 32.692 28.456 21.199 16.416 4.8695

Average of yearly averages: 2.76453

Inputs generated by pe5r.pl - September 2008

Data used for this run:

Output File: LA-Sgc_SlfnAer1pht98

Metfile: w13970.dvf

PRZM scenario: LAsugarcaneSTD.txt

EXAMS environment file: ir298.exv

Chemical Name: Sulfentrazone TTR

Description Variable Name Value Units Comments

Molecular weight mwt 387.2 g/mol

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

Vapor Pressure vapr 9.75E-10 torr

Solubility sol 400 mg/L

Kd Kd mg/L

Koc Koc 29 mg/L

Photolysis half-life kdp 98 days Half-life

Aerobic Aquatic Metabolism kbacw 1750 days Halfife

Anaerobic Aquatic Metabolism kbacs 0 days Halfife

Aerobic Soil Metabolism asm 874.9 days Halfife

Hydrolysis: pH 7 0 days Half-life

Method: CAM 2 integer See PRZM manual

Incorporation Depth: DEPI 0 cm

Application Rate: TAPP 0.4203 kg/ha

Application Efficiency: APPEFF 0.95 fraction

Spray Drift DRFT 0.05 fraction of application rate applied to 

pond

Application Date Date 11-10 dd/mm or dd/mmm or dd-mm or dd-mmm

Record 17: FILTRA

IPSCND 1

UPTKF

Record 18: PLVKRT

PLDKRT

FEXTRC 0.5

Flag for Index Res. Run IR Reservoir

Flag for runoff calc. RUNOFF total none, monthly or total(average 

of entire run)

Drift/Efficiency Source DRFTEFF fixed, basic, or advanced

Input file for RegDISP Advanced REGDISPFILE

Model flag for RegDISP Basic REGDISPMODEL aerial, ground, 

airblast, or chemigation

Buffer BUFFER ft

Maximum Wind Speed MAXWS mph

Flight Direction FLIGHTDIR deg
38
39

APPENDIX

Updated FIRST Modeling Inputs and Results (for additional details see DP Barcode: D28497; 

review dated 4/17/2003):

FIRST Output File

 RUN No. 1 FOR Sulfentrazone ON Citrus etc * INPUT VALUES * 

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

 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE %CROPPED INCORP

 ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) AREA (IN)

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

 .375( .375) 1 1 43.0 400.0 AERIAL(16.0) 87.0 .0

 FIELD AND RESERVOIR HALFLIFE VALUES (DAYS) 

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

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED

 (FIELD) RAIN/RUNOFF (RESERVOIR) (RES.-EFF) (RESER.) (RESER.) 

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

 545.00 2 N/A .50- 62.00 ****** 58.66

 UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.0 JAN 1, 2007

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

 PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC) 

 CONCENTRATION CONCENTRATION 

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

 32.102 5.047

 RUN No. 3 FOR Sulfentraz. acid ON Citrus Etc * INPUT VALUES * 

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

 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE %CROPPED INCORP

 ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) AREA (IN)

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

 .041( .041) 1 1 .0 400.0 GRANUL( .0) 87.0 .0

 FIELD AND RESERVOIR HALFLIFE VALUES (DAYS) 

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

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED

 (FIELD) RAIN/RUNOFF (RESERVOIR) (RES.-EFF) (RESER.) (RESER.) 

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

 .00 2 N/A .00- .00 .00 .00

 UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.0 JAN 1, 2007

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

 PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC) 

 CONCENTRATION CONCENTRATION 

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

 3.735 2.678
40

 

SCIGROW Modeling Input and Results

 

 SCIGROW

VERSION 2.3

 ENVIRONMENTAL FATE AND EFFECTS DIVISION

 OFFICE OF PESTICIDE PROGRAMS

 U.S. ENVIRONMENTAL PROTECTION AGENCY

 SCREENING MODEL

 FOR AQUATIC PESTICIDE EXPOSURE

SciGrow version 2.3

chemical:Sulfentrazone TTR

time is 5/19/2014 14:16: 6

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

---------

 Application Number of Total Use Koc Soil 

Aerobic

 rate (lb/acre) applications (lb/acre/yr) (ml/g) 

metabolism (days)

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

---------

 0.375 1.0 0.375 2.90E+01 

875.0

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

---------

groundwater screening cond (ppb) = 5.75E+01 

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

Results of Vadose Zone Monitoring at Four Prospective Groundwater 

Monitoring Sites

Table 13. Maximum observed concentrations of sulfentrazone and its acid degradate in soil-pore 

water 7- to 9-feet below the surface of treated fields at four sites compared to Tier 1 estimated 

concentrations using the SCI-GROW model.

Chemical NC1 IN1 IN2 IN3 SCIGROW
41

Site Site Site Site

Sulfentrazone 22.5

(186d)

0.28

(911d)

0.35* 

(1229d)

0.09

(1149d)

15.7

3-Carboxylic Acid Sulfentrazone 38.1

(186d)

4.28 

(577d)

3.36

(363d)

0.07

(753d)

10.3

* Also at 0.44 ppb 2135 days after the original application after an additional application 1961 days after the initial 

application. The degradate was detected at a maximum concentration of 0.33 ppb at 2226 days after this last 

application.