UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

OFFICE OF 

CHEMICAL SAFETY AND 

POLLUTION PREVENTION

PC Code: 000692

DP Barcodes: 374622

Date: August 4, 2010

MEMORANDUM

SUBJECT: Tier I Drinking Water Assessment for the Section 3 Proposed Registration of 

Pyrasulfotole on Sorghum and Grass Grown for Seed

TO: Bethany Benbow, Risk Manager Reviewer

Kathryn Montague, Risk Manager

Herbicide Branch

Registration Division

Jennifer Tyler, Risk Assessor

Risk Assessment Branch I

Health Effects Division

FROM: Chuck Peck, Environmental Engineer

Environmental Risk Branch IV

Environmental Fate and Effects Division

THROUGH: Marietta Echeverria, RAPL

Mark Corbin, Acting Branch Chief

Environmental Risk Branch IV

Environmental Fate and Effects Division

Attached is the drinking water exposure assessment for proposed pyrasulfotole use on sorghum 

and grass grown for seed. If additional refinements are necessary, please contact Chuck Peck at (703) 

347-8064 or peck.charles@epa.gov.
2

Drinking Water Exposure Assessment for the Section 

3 Proposed Registration of Pyrasulfotole on Sorghum

And Grass Grown for Seed

N

N

F

F

F

S

CH3

CH3

HO CH3

O

O O

Pyrasulfotole

(5-hydroxy-1,3-dimethyl-1H-pyrazol-4-yl)[2-(methylsulfonyl)-4-

(trifluoromethyl)phenyl]methanone

CAS No. 365400-11-9

Prepared by:

Chuck Peck, Environmental Engineer

Environmental Risk Branch IV

U. S. Environmental Protection Agency

Office of Pesticide Programs

Environmental Fate and Effects Division

Environmental Risk Branch IV

1200 Pennsylvania Ave., NW

Mail Code 7507C

Washington, DC 20460

Reviewed by:

Marietta Ecehverria, RAPL

Mark Corbin, Acting Branch Chief

Environmental Risk Branch IV

Environmental Fate and Effects Division
3

1 EXECUTIVE SUMMARY

This document reports the drinking water exposure assessment for pyrasulfotole that has 

been conducted to support the human health risk assessment for the Section 3 proposed new use 

registration. Pyrasulfotole is a post emergence herbicide currently registered for use on wheat, 

oats, barley and triticale, with proposed new uses on sorghum and grasses grown for seed. Foliar 

spray applications, aerial and ground spray application, are being proposed. Tier 1 surface water 

and groundwater modeling were conducted for the labeled sorghum use of two applications per 

year, at a rate of 0.039 lbs. a.i./A/application and a retreatment interval of 11 days, as specified 

by the proposed HuskieTM label (Reg. No. 264-1023). The recommended estimated drinking 

water concentrations (EDWCs) for the human health risk assessment are in Table 1. There was 

one environmental degradate, pyrasulfotole-benzoic acid (AE 197555), identified in the soil 

metabolism and terrestrial field dissipation studies; however, it is not of toxicological concern 

(HED’s Human Health Risk Assessment for Proposed Uses on Cereal Grains, dated 6/8/2007) 

and is not considered in this assessment.

Table 1. Tier I EDWCs for pyrasulfotole for ground spray applications to sorghum

Drinking Water Source Model Use rate (lbs ai/A) Acute (ppb) Chronic (ppb)

Surface water FIRST 0.039 6.9 4.8

Groundwater SCI-GROW 0.039 2.4 2.4

In a previous drinking water assessment (DP Barcode 330817), EDWCs were estimated

using a single aerial application of 0.045 lb a.i./acre to wheat and barley. Acute and chronic 

surface water EDWCs were 4.0 and 2.8 μg/L, respectively. Acute and chronic groundwater 

EDWCs were 1.4 μg/L.

2 PROBLEM FORMULATION

This is a Tier I drinking water assessment that uses modeling and available monitoring 

data to estimate the groundwater and surface water concentrations in drinking water sources 

(pre-treatment) resulting from pesticide use on sites that are vulnerable. This initial tier screens 

out chemicals with low potential risk and allows OPP to focus resources on more refined risk 

assessments for chemicals which potentially present more significant risks. This drinking water 

assessment reports potential exposure concentrations for the human health dietary risk 

assessment and provides a description of how those concentrations were determined. 

3 ANALYSIS

3.1 Use Characterization

Pyrasulfotole is a post emergence herbicide that is applied as a foliar spray twice a year at 

a maximum single application rate of 0.039 lb a.i./A on sorghum (via ground) and 0.036 lb a.i./A 

on grass grown for seed (via ground and aerial). There is one pyrasulfotole end-use product 

being proposed for registration in the United States for use on sorghum and grass grown for seed, 
4

HuskieTM Herbicide (Reg. No. 264-1023, an emulsifiable concentrate containing 3.3% 

pyrasulfotole) (Table 2).

Table 2. Proposed maximum use patterns for pyrasulfotole

Product (% a.i.) Uses Application 

methods

Maximum 

application 

rate/year1

Maximum number of 

applications/year

Huskie Herbicide 

(3.3%)

Sorghum Ground 0.039 lb a.i./acre 

2 Grasses grown for 

seed

Ground

Aerial 0.036 lb a.i./acre

1

 The application rate on the label was converted to lbs a.i./acre based on the following: The formulated product density = 0.31 lbs ai/gal; the 

formulation is 3.3% pyrasulfotole; the max application rate of 15 oz of formulated product/acre (grasses grown for seed) and 16 oz of formulated 

product/acre (sorghum) are allowed.

3.2 Environmental Fate and Transport Characterization

Pyrasulfotole is expected to be persistent and mobile to moderately mobile (FAO 

classification) in the environment. Major routes of dissipation include microbial degradation in 

soils, formation of non-extractable residues in soils and sediments, and dilution.

Under aerobic conditions pyrasulfotole degraded in 3 soils (loamy sand, silt loam, sandy

loam) according to an apparent bi-phasic pattern with observed DT50s ranging from 4-65 days

and observed DT90sranging from >120->358 days. A 2-compartment, 4-parameter exponential 

model, also known as Double First Order Parallel (DFOP), was used to fit the data and resulted 

in modeled DT50s ranging from 6-63 days and DT90s ranging from 208-1424 days (MRIDs 

46801709, 406801710, 46801711). Degradation products included pyrasulfotole-benzoic acid 

(AE 197555), CO2 and non-extractable residues. Non-extractable residues were identified at 

maximums of 35-62% of applied radioactivity in the 3 soils. The non-extractable residues are 

uncharacterized and it is uncertain whether they consist of degradates of risk concern. Under 

sterile conditions, however, the formation of non-extractable residues (as well as the formation 

of CO2 and the benzoic acid degradate) were negligible. In terrestrial field dissipation studies 

pyrasulfotole dissipated from the whole soil profile with modeled (DFOP) DT90s ranging 44-531 

days and the amount of parent pyrasulfotole carry over to the following growing season ranged 

from 4.7 to 37% (MRIDs 46801716, 46801717, 46801718, 46801719). 

In aquatic systems, pyrasulfotole is stable to hydrolysis and photolysis (MRIDs 

46801705, 46801706). In aerobic aquatic metabolism studies, pyrasulfotole partitioned to the 

sediment and formed non-extractable residues but there was no evidence of degradation. 

Pyrasulfotole is also considered stable to microbial degradation in aquatic systems (MRID 

46801713) and under anaerobic conditions (MRIDs 46801712, 4681714, 46801715). 

Batch equilibrium studies resulted in organic carbon sorption coefficients (Koc) ranging 

from 20 to 345 ml/goc with a median value of 68 ml/goc (MRID 46801703). In terrestrial field 

dissipation studies pyrasulfotole showed variable downward migration in the soil profile under 

bare soil conditions. In some studies pyrasulfotole was confined to 0-15 cm whereas in others it 

was detected at quantifiable levels as deep as 75-90 cm (MRIDs 46801716, 46801717, 

46801718, 46801719). Since pyrasulfotole has a Kd less than 5 in most soils and is persistent 

(hydrolysis half-life greater than 25 weeks, photolysis half-life greater than 1 week, aerobic soil 

metabolism half-life greater than 2-3 weeks), not volatile (Henry’s Law constant less than 10-2

atm/m

3

/mol), and shows movement to 45 cm during some field dissipation studies, there is 
5

indication for potential groundwater contamination (Cohen 1984). Depending on soil, site and 

meteorological conditions pyrasulfotole may be transported off-site to drinking water sources via 

runoff, leaching and spray drift. Table 3 summarizes the registrant-submitted environmental fate 

and transport properties of pyrasulfotole. 

There was one major degradate, pyrasulfotole-benzoic acid (AE 197555), detected in the 

aerobic soil metabolism and terrestrial field dissipation studies. However, drinking water 

exposure to the benzoic acid degradate is not considered of toxicological concern (HED’s 

Human Health Risk Assessment for Proposed Uses on Cereal Grains, dated 6/8/2007).

Table 3 Summary of environmental chemistry and fate properties of pyrasulfotole

Parameter Value Reference/Comments

Selected Physical/Chemical Parameters

PC code 000692

CAS No. 365400-11-9

Chemical name (5-hydroxy-1,3-dimethylpyrazol-4-yl)(α,α,α-trifluoro2-mesyl-p-tolyl)methanone

Chemical formula C5H13Cl2N

Molecular weight 362.3 g/mol

Water solubility (20 °C)

pH 4

pH 7

pH 9

4.2 g/L

69 g/L

49 g/L

MRID 46801702

Vapor pressure 2.7 x 10-7

Pa (20C)

6.8 x 10-7Pa (25C)

MRID 46801702

log KOW

pH 4

pH 7

pH 9

0.276 

-1.36 

-1.58 

MRID 46801702

Persistence

Hydrolysis Stable (pH = 5, 7, 9) MRID 46801705

Photolysis in water Stable MRID 46801706

Photolysis in soil t1/2 = 227 days MRID 46801707

Environmental 

phototransformation half-life 

based on sunlight expected in 

Pheonix, AZ (33.26o N)

Aerobic soil metabolism Soil Type DT50

(days)

DT90

(days)

R

2 MRIDs 46801709, 46801710, 

46801711

2 compartment, 4 parameter 

exponential model (DFOP) 

Loamy sand 5.8 749 0.977

Silt loam 63 1424 0.998

Sandy loam 23 208 0.990

Anaerobic soil 

metabolism 

Stable MRID 46801712
6

Table 3 Summary of environmental chemistry and fate properties of pyrasulfotole

Parameter Value Reference/Comments

Aerobic aquatic 

metabolism 

Stable MRID 46801713

Anaerobic aquatic 

metabolism 

Stable MRIDs 46801714, 46801715

Mobility

Batch equilibrium Soil Type Kf

1

1/N Koc

2 MRID 46801703

Silt loam 0.98 0.93 21

Loamy sand 1.2 0.91 100

Clay loam 0.34 0.98 20

Sandy loam 0.39 0.95 35

Silt loam 3.2 0.93 213

Sandy loam 16 0.83 345

Laboratory volatility NA Volatility not likely based on 

low vapor pressure

Field Dissipation

Terrestrial field 

dissipation

Location DT50

(days)

DT90

(days)

% carry over MRIDs 46801716, 46801717, 

46801718, 46801719

Kansas 8.9 45 4.7

North Dakota 5.7 44 7.7

Washington 5.7 213 11

Saskatchewan 10 260 37

Manitoba 9.2 531 19

Ontario 18 178 8.9

Bioaccumulation

Accumulation in fish, 

BCF

No data Bioaccumulation is not 

expected based on low log Kow

1. Units of (mg/kg)/(mg/L)1/N, where 1/N is the Freundlich exponent.

2. Approximation calculated from the Freundlich coefficient, per standard EFED guidance.

3.3 Drinking Water Exposure Modeling

Tier 1 modeling was used to estimate the drinking water exposure for use in the dietary

risk assessment of pyrasulfotole. The following is a description of the models used, the selection 

of the model input parameters, and a characterization of the output from these simulations.

3.3.1 Models

EDWCs were generated using EFED’s standard suite of models. The FQPA Index 

Reservoir Screening Tool (FIRST) is a surface water model that is used to estimate both acute 

and chronic potential pesticide concentrations in untreated drinking water. EDWCs from FIRST 

represent concentrations which might occur from a single 1-in-10-year storm event following the 

last application of pesticide at a location more vulnerable than most locations in the United 

States to runoff, regardless of the crop being produced. The model considers reductions in 

dissolved concentration due to the percentage of the watershed which is cropped (percent 
7

cropped area - PCA), due to adsorption of pesticide to field soil and to reservoir bottom 

sediment, due to incorporation of the pesticide at the time of application, due to degradation in 

soil before washoff to the reservoir, and due to degradation of the pesticide within the water 

body. Reservoir water concentrations may be increased due to deposition of spray drift into the 

feeding stream or directly into the reservoir itself. FIRST is designed to mimic a more complex 

simulation using the linked PRZM3 (Carsel et. al., 1997) and EXAMS 2.97.7 (Burns et. al., 

2000) models, but requires less time and effort to complete. A more detailed description of the 

index reservoir watershed can be found in Jones et al., 1998. The FIRST model and users 

manuals may be downloaded from the U.S. Environmental Protection Agency (EPA) Water 

Models web-page. PCAs that account for the maximum area within a watershed that may be 

planted with the modeled crop are applied to concentrations predicted by PRZM/EXAMS.

Screening Concentration in Ground Water (SCI-GROW v2.3, Jul. 29, 2003) is a 

regression model used as a screening tool to estimate pesticide concentrations found in ground 

water used as drinking water. SCI-GROW was developed by fitting a linear model to ground 

water concentrations with the Relative Index of Leaching Potential (RILP) as the independent 

variable. The RILP is a function of aerobic soil metabolism and the soil-water partition 

coefficient. The output of SCI-GROW represents the concentrations of isoxaben residue that 

might be expected in shallow unconfined aquifers under sandy soils, which is representative of 

the ground water most vulnerable to pesticide contamination and likely to serve as a drinking 

water source. The SCI-GROW model and user’s manual may also be downloaded from the EPA 

Water Models web-page (USEPA, 2006).

3.3.2 Modeling Approach and Input Parameters

Tables 4 and 5 summarize the model input parameter values used in FIRST and 

SCIGROW, respectively. These parameters were selected in accordance with EFED’s input 

parameter guidance (Environmental Fate and Effects Division, 2009). To estimate first order 

half-lives (rate constants) for exposure modeling, the DFOP modeled DT90s were divided by 

3.32 (the ratio between DT50 and DT90 for first order reactions). This is currently a provisional 

method under evaluation by EFED for use in biphasic studies that do not fit the traditional first 

order linear or nonlinear model, where the observed DT90s extend beyond the study duration, 

and the estimated half-lives from the DFOP model tend to be more conservative. An aerobic soil 

metabolism first order half-life of 439 days (the upper 90th percentile confidence bound on the 

mean) was used for surface water modeling with FIRST and the median value, 226 days, was 

used for groundwater modeling with SCIGROW. The soil-water partitioning coefficient used in 

FIRST and SCIGROW was 20 ml/goc, the lowest non-sand Koc. The lowest Koc value was used 

in SCIGROW because there was greater than 3-fold variability in the available data.

Table 4. FIRST input parameter values for pyrasulfotole applied to sorghum

Parameter Value Source Comments

Application Rate (lb 

a.i./A)

0.039 Huskie Herbicide Label 

(3.3%)

Number of Applications 2 Huskie Herbicide Label 

(3.3%)
8

Table 4. FIRST input parameter values for pyrasulfotole applied to sorghum

Parameter Value Source Comments

Retreatment Interval 

(days)

11 Huskie Herbicide Label 

(3.3%)

Soil Partitioning 

Coefficient (Koc; ml/goc)

20 MRID 46801703 lowest non-sand value 

Aerobic Soil Metabolism 

t1/2 (days)

439 MRIDs 46801709, 

46801710, 46801711

90th percentile upper confidence bound on the 

mean where t1/2 is estimated by DT90/3.32

Wetted in? No foliar applied

Depth of Incorporation 

(inches)

0 foliar applied

Method of Application Ground

spray

AE 0317309 SE06 

Herbicide (4.4%)

Percent Cropped Area 0.87 National default

Solubility in Water 

(mg/L)

6.9 x 104Product chemistry data

Aerobic Aquatic 

Metabolism t1/2 (days)

0 MRID 46801713 Stable to aquatic metabolism

Hydrolysis t1/2 (days)

0 MRID 46801705 Stable to hydrolysis

Aquatic Photolysis t1/2

(days)

0 MRID 46801706 Stable to photolysis

Table 5. SCIGROW input parameter values for pyrasulfotole applied to sorghum.

Parameter Value Source Comments

Maximum Application Rate 

(lb a.i./A/application) 0.039 Huskie Herbicide Label (3.3%)

Maximum Number of 

Applications per Year 2

Huskie Herbicide Label 

(3.3%)

Aerobic Soil Metabolism Half-life 

(days)

226 MRIDs 46801709, 

46801710, 46801711

median value where t1/2 is 

estimated by DT90/3.32

Organic Carbon Partition 

Coefficient (Koc, ml/goc)

20 MRID 46801703 Lowest value; > 3x variability in 

data

3.3.3 Modeling Results

The FIRST and SCI-GROW output files are located in Appendix A. Based on the results 

of these simulations, EFED recommends an acute surface water EDWC of 6.9 μg/L and a 

chronic EDWC of 4.8 μg/L for use in the human health risk assessment. These 

recommendations are based on the use of pyrasulfotole on sorghum at an annual application rate 
9

of 0.078 lb a.i./A/year. The recommended EWDC for groundwater is 2.4 μg/L and is also based 

on the use of pyrasulfotole on sorghum at the previously stated rate. 

3.4 Monitoring Data

Pyrasulfotole is not included as one of the analytes monitored in U.S. surface and 

groundwater under the USGS’s National Water Quality Assessment (NAWQA) program 

(http://water.usgs.gov/nawqa) or in surface water or sediment samples collected by California 

Department of Pesticide Regulation (CDPR) (http://cdpr.ca.gov/docs/emon/surfwtr/

surfcont.htm).

3.5 Drinking Water Treatment

There is no available information on the drinking water treatment effects on 

pyrasulfotole. The EDWCs in this assessment are representative of concentrations in drinking 

water source water (pre-treatment). For surface water, the conceptual model assumes that a 

pesticide reaches surface water via spray drift or surface runoff, where it is instantaneously

mixed and concentrations are observed in the water body. Pyrasulfotole is stable to hydrolysis. 

Therefore, pyrasulfotole will not degrade by hydrolysis during the time that elapses from 

drinking water intake through distribution to the first tap. Because of its low Koc values, 

treatment methods such as sedimentation, flocculation, and activated carbon, are not expected to 

be effective at removing pyrasulfotole. Pyrasulfotole does not degrade due to photolysis or

aerobic aquatic metabolism. Therefore, if ultraviolet light were used as a means of disinfection, 

degradation of pyrasulfotole would not be expected. Additionally, while unlikely, if an aerobic 

digester were used in the drinking water treatment train, degradation would not be expected to

occur. 

4 CONCLUSIONS

The estimated concentrations provided in this assessment are conservative estimates of 

pyrasulfotole concentrations in untreated drinking water. A major source of uncertainty is the 

nature of the non-extractable residues formed during degradation in soils. Non-extractable 

residues are identified at maximums of 35-62% of applied radioactivity in 3 soils. The nonextractable residues are uncharacterized and it is uncertain whether they consist of degradates of 

risk concern. Under sterile conditions these non-extractables are not formed suggesting that the 

formation of them is microbially mediated. 

The Tier I drinking water assessment is a screening-level assessment based on simplified 

models and assumptions. The modeling assessment relies on maximum use patterns and national 

default PCAs to reflect potential surface and groundwater concentrations. To the extent that 

actual use patterns are less than the labeled maximums and the location-specific PCAs are less 

than assumed in this assessment, actual environmental exposures could be lower. As such, if 

EDWCs exceed levels of concern, refinements can be made to this assessment to account for 

regional use patterns. 
10

References

Burns, L.A. 2000. Exposure Analysis Modeling System (EXAMS), Environmental Research 

Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, 

Athens, GA.

R.F. Carsel, J.C. Imhoff, P.R. Hummel, J.M. Cheplick and J.S. Donigian, Jr. 1997. PRZM-3, A 

Model for Predicting Pesticide and Nitrogen Fate in Crop Root and Unsaturated Soil Zones: 

Users Manual for Release 3.0; Environmental Research Laboratory, Office of Research and 

Development, U.S. Environmental Protection Agency, Athens, GA.

Cohen, S.Z., Creeger, S.M., Carsel, R.F., Enfield, C.G. In “Treatment and Disposal of Pesticide 

Wastes;” Krueger, R.F., Seiber, J.N., Eds.; ACS Symposium Series No. 259, American Chemical 

Society: Washington, DC, 1984; pp. 297-325.

Environmental Fate and Effects Division. 2008. FIRST (F)IFRA (I)ndex (R)eservoir 

(S)creening (T)ool. Tier 1 Model for Drinking Water Exposure: User's Manual.

http://www.epa.gov/oppefed1/models/water/first_v1_1_1_user_manual.htm

Environmental Fate and Effects Division. 2003. SCIGROW: Users Manual. Online at: 

http://www.epa.gov/oppefed1/models/water/#scigrow

Environmental Fate and Effects Division. 2009. Guidance for Selecting Input Parameters in 

Modeling the Environmental Fate and Transport of Pesticides, Version 2.1. U. S. Environmental 

Protection Agency. Washington, D.C. October 29, 2009. http://www.epa.gov/oppefed1/models/

water/input_parameter_guidance.htm 

Health Effects Division. 2007. Memorandum from Jennifer Tyler (HED) to Tracy White (RD), 

Subject: Pyrasulfotole: Human-Health Risk Assessment for Proposed Uses on Small Cereal 

Grains. PC Code: 000692. PP#: 6F7059. DP#: 328640. Decision #: 366490. 6/8/2007.

Jones, R. D., S. Abel, W. R. Effland, R. Matzner, R. Parker. 1998. An Index Reservoir for Use 

in Assessing Drinking Water Exposure. Proposed Methods for Basin-scale Estimation of 

Pesticide Concentrations in Flowing Water and Reservoirs for Tolerance Reassessment. 

Presentation to FIFRA Science Advisory Panel, June 29-30, 1998. Online at: 

http://www.epa.gov/scipoly/sap/1998/index.htm

MRIDs

MRID 46801702

Fontaine, L. (2006) Product Chemistry of Pyrasulfotole Technical. Project Number: BR/2470, 

PA03/044, PA05/102. Unpublished study prepared by Bayer Corp. 323 p.
11

MRID 46801703

Maurer, T.; Eyrich, U.; Fliege, R. (2003) Adsorption/Desorption of AE 0317309 on Five Soils 

and One Sediment. Project Number: CP/02/014, MO/03/012996, MEF/186/03. Unpublished 

study prepared by Bayer Cropscience Gmbh. 84 p.

MRID 46801705

Ripperger, R. (2004) [Pyrazole-3-(Carbon 14)] AE0317309: Hydrolytic Degradation. Project 

Number: 200578, A9072401. Unpublished study prepared by Bayer Corp. 59 p.

MRID 46801706

Ripperger, R.; Meyer, B. (2005) [(Carbon 14)-UL-Phenyl] and [(Carbon 14)-3-Pyrazole] AE 

0317309: Phototransformation in Water. Project Number: 200987, A9082401. Unpublished 

study prepared by Bayer Corp. 64 p.

MRID 46801707

Arthur, E.; Shepherd, J.; Dominic, A. (2004) [Pyrazole-3-(Carbon 14)] AE 0317309: 

Phototransformation on Soil. Project Number: 200638, A9082101. Unpublished study prepared 

by Bayer Corp. 85 p.

MRID 46801709

Fliege, R. (2004) [Phenyl-U-(Carbon 14)]- and [Pyrazole-3-(Carbon 14)]-AE 0317309: Aerobic 

Soil Metabolism in a Loamy Sand Soil of US Origin Under Laboratory Conditions at 25 degrees 

C. Project Number: MEF/386/03, CB/02/011. Unpublished study prepared by Bayer 

Cropscience Gmbh. 129 p.

MRID 46801710

Fliege, R. (2004) [Phenyl-U-(Carbon 14)]- and [Pyrazole-3-(Carbon 14)]-AE 0317309: Aerobic 

Soil Metabolism in a Soil Metabolism in a Silt Loam Soil of US Origin Under Laboratory

Conditions at 25 degrees C. Project Number: MEF/387/03, CB/02/012. Unpublished study

prepared by Bayer Cropscience Gmbh. 116 p.

MRID 46801711

Fliege, R. (2005) [Phenyl-UL-(Carbon 14)] and [Pyrazole-3-(Carbon 14)] AE 0317309: Aerobic 

Soil Metabolism in a European Soil. Project Number: MEF/05/459, M1251487/8. Unpublished 

study prepared by Bayer Ag, Institute of Product Info. & Residue Anal. 108 p.

MRID 46801712

Ripperger, R. (2005) [Phenyl-UL-(Carbon 14)] and [Pyrazole-3-(Carbon 14)] AE 0317309: 

Anaerobic Soil Metabolism. Project Number: 04MEAIP001, MEAIP001. Unpublished study

prepared by Bayer Corp. 92 p.

MRID 46801713

Allan, J.; Cheung, C. (2006) [Pyrazol-3-(Carbon 14)] AE 0317309 and [Phenyl-UL-(Carbon 14)] 

AE 0317309: Aerobic Aquatic Metabolism. Project Number: MEAIM008, A9042104. 

Unpublished study prepared by Bayer Corp. 101 p.
12

MRID 46801714

Shepherd, J.; Arthur, E. (2005) [Phenyl-UL-(Carbon 14)] AE 0317309: Anaerobic Aquatic 

Metabolism. Project Number: 200593, A9042102. Unpublished study prepared by Bayer Corp. 

72 p.

MRID 46801715

Arthur, E.; Shepherd, J. (2005) [Pyrazole-3-(Carbon 14)] AE 0317309: Anaerobic Aquatic 

Metabolism. Project Number: 200495, A9042101. Unpublished study prepared by Bayer Corp. 

71 p.

MRID 46801716

Lenz, M. (2006) Terrestrial Field Dissipation of AE 0317309 in Kansas Soil, 2004. Project 

Number: MEAIY008, AI/002/S05/02. Unpublished study prepared by Bayer Corp., Agvise Inc. 

and Diamond Ag Research, Inc. 191 p.

MRID 46801717

Lenz, M. (2006) Terrestrial Field Dissipation of AE 0317309 in North Dakota Soil, 2004. 

Project Number: MEAIY007, AI/002/S05/02. Unpublished study prepared by Bayer Corp., 

Agvise Laboratories, and Agvise Research. 188 p.

MRID 46801718

Lenz, M. (2006) Terrestrial Field Dissipation of AE 0317309 in Washington Soil, 2004. Project 

Number: MEAIY009, AI/002/S05/02. Unpublished study prepared by Bayer Corp., Agvise Inc. 

and Qualls Agricultural Laboratories, I. 195 p.

MRID 46801719

Belyk, M. (2006) Terrestrial Field Dissipation of AE 0317309 in Canada, 2003-2004. Project 

Number: 03BCS01, MEAIM004, AI/002/S05/01. Unpublished study prepared by Bayer Corp., 

Vaughn Agricultural Research Serv., Ltd. and Ag-Quest Inc. 333 p.
13

Appendix A: Input/Output Modeling Files

FIRST File

 RUN No. 1 FOR pyrasulfotole ON sorghum * INPUT VALUES * 

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

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

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

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

 0.039( 0.077) 2 11 20.069000.0 GROUND( 6.4) 87.0 0.0

 FIELD AND RESERVOIR HALFLIFE VALUES (DAYS) 

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

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED

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

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

 439.00 2 N/A 0.00- 0.00 0.00 0.00

 UNTREATED WATER CONC (MICROGRAMS/LITER (PPB)) Ver 1.1.1 MAR 26, 2008

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

 PEAK DAY (ACUTE) ANNUAL AVERAGE (CHRONIC) 

 CONCENTRATION CONCENTRATION 

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

 6.894 4.794

SCIGROW File

 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:pyrasulfotole

time is 7/29/2010 11:11:15

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

 Application Number of Total Use Koc Soil Aerobic

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

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

 0.039 2.0 0.078 2.00E+01 226.0

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

groundwater screening cond (ppb) = 2.36E+00 

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