UNITED ST A TES ENVIRONMENTAL PROTECTION 

AGENCY 

WASlll GTO D.C.. 20460 

OHICFOr 

PR!: Vf'\;TIO'I. 

PESTICIDES AND 

TOXIC SUBSTt\ NC!-S 

PC Code: 11 1401 

DP Barcode: D425755 

September 14, 2015 

MEMORANDUM 

SUBJECT: Drinking Water Assessment for Profenofos for Registration Review. 

TO: Christina Scheltema, Chemical Review Manager 

Kelly Sherman, Branch Chief 

FROM: 

Risk Management and Implementation Branch 3 

Pesticide Re-evaluation Division (7508P) 

AND 

Sarah Levy, Dietary Assessor 

Charles Smith, Branch Chief 

Risk Assessment Branch 1 

Health Effects Division (7509P) 

Michelle Colletti, Chemist J . I;// ' f c 17 0 er l,y I I< 

William P. Eckel, Ph.D., Senior Science Advisor /W~ . e-f-1 /

1 

Environmental Risk Branch 6 

Environmental Fate and Effects Division (7507P) 

THROUGH: MonicaWait, RAPL ~ W~ C\/IL\-/\5 

Mark Corbin, Branch Chief tJ1 1 0 I. ) g Environmental Risk Branch 6 ~ '- -) ~-\ ')" 

Environmental Fate and Effects Division (7507P) 

This memo describes the Tier 2 estimated drinking water concentrations (EDWCs) for 

profenofos in surface water and the Tier 1 estimates of drinking water concentrations in ground 

water for the registration review of profenofos for human health risk assessment. The 

recommended EDWCs for profenofos are based on the onl y currently registered use site, cotton, 

which is grown in several states. The modeled use pattern and locations represent values that 

are expected to be exceeded only rarely (once every ten years) in drinking water in watersheds 
2

where cotton is grown. The percent cropped area (PCA) for cotton, 0.21, was used for a 

national assessment.

The recommended EDWCs modeled using the Surface Water Concentration 

Calculator (SWCC) for the surface water drinking water exposure assessment for

registration review are 5.92 μg/L (ppb) for the peak concentration, 0.283 μg/L for the 

annual mean concentration, and an overall mean concentration of 0.167 μg/L. The highest 

peak concentration, the highest annual, and overall mean values occurred with the Texas cotton 

organophosphate scenario. This scenario, set in Milam County, Texas, between Dallas and 

Houston, was developed for the OP cumulative human health risk assessment.

The highest estimated ground water concentration modeled using PRZM-GW is 2.51 

μg/L over 30 years and 16 μg/L over 100 years. All PRZM-GW scenarios are set in vulnerable 

soil and weather combinations. Breakthrough to the aquifer was not observed over either a 30 

year period or a 100 year period. The highest peak concentration values for ground water 

occurred with the Florida citrus scenario, which stands as a surrogate for scenarios of cotton 

grown in Georgia or North Florida.

Table 1. Estimated Drinking Water Concentrations (EDWC) of profenofos residues for 

cotton in an Index Reservoir with the SWCC model. 

The simulations used the maximum labeled number (10) of applications and application rate (0.5 lb.

a.i./A/application), and a maximum seasonal application rate (5 lb. a.i./A). The concentrations have been 

adjusted with the Percent Cropped Area (PCA) of 0.21 for cotton for a national assessment.

1-in-10 year Profenofos Concentration (μg/L) Concentration (μg/L)

Scenario -State Crop Peak Annual Mean Overall Annual 

Mean

CA - Cotton 0.527 0.0382 0.0365

MS – Cotton 4.87 0.214 0.113

NC - Cotton 4.43 0.206 0.0945

TX – Cotton 5.92 0.283 0.167

1 The bold values represent the recommend EDWCs to be use in the drinking water assessment.

2 The SWCC model results can be found in Appendix 1

Use Characterization

Profenofos is an insecticide/miticide belonging to the organophosphate class of 

pesticides. The toxicity of organophosphates is based on the inhibition of the enzyme 

acetylcholinesterase which cleaves the neurotransmitter acetylcholine. Inhibition of 

acetylcholinesterase by organophosphate insecticides interferes with proper neurotransmission in 

cholinergic neurosynapses and neuromuscular junctions. Profenofos is registered for use only 

on cotton and can be applied by enclosed cab ground application equipment to control cotton 

bollworm, tobacco budworm, certain other listed insects, and mites. Aerial application is not 

permitted. The maximum single application rate of profenofos is 0.5 lb. a.i. /A with a minimum 
3

application interval of 5 days and a seasonal maximum application rate of 5 lb. a.i. /A (maximum 

of 10 applications per season). Profenofos application is prohibited within 100 ft. of any body 

of water. A spray drift percentage was calculated in AgDrift (v 2.1.1) using a high boom setting 

and fine to medium droplet size distribution (EFED, 2001).

Table 2 Maximum Application Parameters for Profenofos

Application

Use site Maximum Rate 

(lbs a.i./acre) Interval (days) Date

Maximum Annual 

(lbs a.i./acre)

Cotton 0.5 lbs a.i./acre 5 days

(10 applications)

First application date on 

emergence in SWCC

(June 1) 

5 lbs a.i./acre

Chemical Name: O-(4-bromo-2-chlorophenyl) O-ethyl S-propyl phosphorothioate

Environmental Fate and Transport:

Based on available laboratory studies, profenofos degrades primarily by microbial 

metabolism as well as the abiotic process of hydrolysis. The half-lives used in this assessment 

were recalculated from original study results using the currently accepted model PestDF (EFED, 

2014). Aerobic and anaerobic soil metabolism half-lives are similar, 2.3 and 2.1 days 

respectively. Degradation due to hydrolysis varies with pH, with half-lives ranging from 107-

475 days for acidic (pH 5) waters, 24.4-69.9 days for waters with neutral pH (pH 7), and 0.32-

0.43 days for alkaline waters (pH 9). The half-life of profenofos, under anaerobic aquatic 

conditions, due to metabolism is 3.8 days at 25 °C. The values of the photolysis half-life were 

compared to the hydrolysis half-lives at pH 5 (MRIDs 41627309, 41939001). The dark 

corrected photolysis half- life was found to be 266 days.

The predominant degradate of profenofos observed in laboratory studies (including 

hydrolysis, photolysis, and metabolism) was 4-bromo-2-chlorophenol, which was formed by 

hydrolysis of the organophosphate group from the phenyl ring of profenofos. Also formed in 

equimolar parts with this degradate is O-ethyl-S-propyl phosphorothioate. According to the 

July 28, 1995 memo “Profenofos. Outcome of the 7/18/95 Meeting of the HED Metabolism 

Committee” (HED, 1995), the parent compound, profenofos, is the only residue of concern for 

the human health risk assessment. 

An available laboratory study indicates that profenofos has a slight mobility potential to 

leach in soils. The organic carbon partition coefficient (KOC) was determined to be 3890 (MRID 

48612101). No scientifically valid studies are available to define the volatility of profenofos. 

The estimated vapor pressure is given as 9.30 x 10-7 torr (British Crop Protection Council, 1997). 

The environmental fate data and values used in the drinking water modeling are summarized in 

Table 3. 
4

Table 3. Summary of environmental fate parameters for profenofos and values used for 

modeling (SWCC and PRZM-GW).

Parameter Range Value Used in Model Source

Molecular Weight 373.63 (g/mol) 373.63 (g/mol) Product chemistry

Solubility in water 20 mg/L 20 mg/L IRED (USEPA 2000)

Vapor Pressure 9.30 x 10-7 torr 9.30 x 10-7 torr The Pesticide Manual, 

1997, p. 1006

Hydrolysis T1⁄2 (at 25 °C)1

107 – 475 (pH 5)

24.4 – 69.9 (pH 7)

0.32 -0.43 (pH 9)

69.9 days MRID 41627309, 

41939001

Aquatic Photolysis T1⁄2

1 T1⁄2 = 266 days 266 days MRID 41939002

Aerobic Soil Metabolism 

T1⁄2

1 2.3 days @ 25 °C 6.9 days

2.3 days x 3

MRID 42334302

(EFED, 2009)

Anaerobic Soil

Metabolism T1⁄2

1 2.1 days @ 25 °C MRID 42334303

Water Column 

Metabolism T1/2

1

13.8 days @ 25 °C

6.9 days x 2 (EFED, 2009)

Anaerobic Aquatic 

Metabolism, T1⁄2

1 3.8 days @ 25 °C 3.8 days @ 25 MRID 42218101

Sorption Koc 3890 (mL/g) 3890 (mL/g) MRID 48612101

Application Efficiency 0.99 ground spray (EFED, 2009)

Foliar Half-Life 35 days (EFED, 2009)

Spray Drift % 0.0042 AgDrift (v 2.1.1)

Henry’s Law Constant 2.38 x 10-7

atm-m3

mol-1

2.38 x 10-7atm-m3

mol-1 (EFED, 2008)

Diffusion in Air 0.032980 cm2/d (EFED, 2003)

Enthalpy 8.1 kcal/mol (EFED, 2003)

1

Half-lives were recalculated using PestDF (EFED, 2014)

Monitoring Data

Monitoring data for profenofos were downloaded from the Water Quality Portal database

(http://waterqualitydata.us/) on June 04, 2015. The Water Quality Portal integrates data from 

the USGS National Water Information System (NWIS), EPA’s STORET data warehouse, and 

USDA ARS STEWARDS platform. A total of 2,336 records were retrieved for the analysis of 

profenofos. The data covered a time period from 1993 to March 2015. Twenty eight states were 

represented in the data set including (states that are bold represent cotton growing states): AZ, 

CA, AL, AR, CO, CT, FL, GA, HI, IN, KY, MA, MD, MI, MN, MO, NC, NE, NV, NY, OH, 

OR, PA, TX, VA, WA, and WI. All of the samples were non-detects.
5

Data from California Department of Pesticide Regulation was also accessed for this 

assessment on June 08, 2015. The sampling period for which profenofos was monitored in 

surface and ground water was 2002-2005, and 2007-2009. A total of 735 records were 

retrieved, all of which were non-detects with a limit of quantitation of 0.05 ppb. The CADPR 

surface water database can be found at: http://www.cdpr.ca.gov/docs/emon/surfwtr/surfcont.htm.

Groundwater data provided by the Texas Commission of Environmental Quality (TCEQ) 

to the EPA returned 245 results. A total of 245 results were retrieved and occurred in the years 

1987, 1988, 1990, and 2003. All of the results were non-detects with a limit of quantitation of 

0.0059 ppb.

None of the data listed above is a result of sampling targeted to profenofos use. That 

coupled with a less robust sample frequency would suggest that the monitoring results are 

probably missing the peak concentrations of profenofos, if and when it is used. Mallampalli 

(2014) reports that profenofos use has declined sharply since 1998, thus it is less likely that it 

would be detected in ambient monitoring.

Simulation Modeling

Surface Water - Drinking Water

For Tier 2 surface water assessments, the Surface Water Concentration Calculator 

(SWCC) version 1.106 (EFED, 2014), was used to estimate environmental fate and transport of 

the active ingredient profenofos in surface waters. The Tier 2 assessment reports the EDWCs

for profenofos that are expected once every ten years. The estimates are generated using 30-

years of meteorological data, encompassing the years from 1961 to 1990. For further 

information on these models see: http://www.epa.gov/oppefed1/models/water/index.htm.

The profenofos concentrations simulated by SWCC assume that 100% of the watershed is 

planted to the simulated crop. The raw SWCC concentrations (output) are then multiplied by 

the PCA (percent cropped area) factor for cotton to account for the less than 100% coverage by 

the crop in a watershed large enough to support a drinking water facility. The SWCC output 

concentrations multiplied by the PCA are the estimated drinking water concentrations (EDWC). 

PCAs are the maximum proportion of a drinking water basin that might be planted with a 

specific crop (EFED, 2014). The PCA (percent crop area) for cotton was determined to be 0.21. 

Scenario Selection

The only registered use of profenofos is for cotton. To calculate the EDWCs, all four

modeling scenarios relevant to cotton were selected for use in SWCC. These scenarios

(CAcotton, TXCotton OP, MScotton, and NCcotton) are representative of the Western, Southern, 

and Eastern growing regions respectively. Generally, off-site transport is controlled by spray 

drift in the drier growing regions, such as California. Run-off also contributes in wetter areas 

such as the east.
6

Profenofos is labeled for application only by ground spray. Up to 10 profenofos

applications may be applied per season with a maximum single application rate of 0.5 lbs a.i./A

and annual maximum application rate of 5 lbs a.i./acre. The minimum reapplication interval is 5 

days.

Ground Water

Tier 1 ground water EDWCs for profenofos, resulting from its use on cotton were derived 

with PRZM-GW (Pesticide Root Zone Model for Groundwater, version 1.0, August 31, 2012).

PRZM-GW accounts for pesticide fate in the crop root zone by simulating pesticide transport and 

degradation through the soil profile after a pesticide is applied to an agricultural field. PRZMGW permits the assessment of multiple years of pesticide application (up to 100 years) on a 

single site. Six standard scenarios, each representing a different region known to be vulnerable 

to groundwater contamination, are available for use with PRZM-GW for risk assessment 

purposes. The WI sands scenario was excluded from modeling of profenofos for ground water 

EDWCs since it is outside the US cotton growing region and therefore not relevant. PRZM-GW 

output values represent pesticide concentrations in a vulnerable groundwater supply that is

located directly beneath a rural agricultural field. For this reason, use of a PCA adjustment 

factor is not appropriate for PRZM-GW. For further information on this model see: 

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

PRZM-GW estimates likely ground water concentrations if the pesticide is used at the 

maximum allowable application rate in areas where ground water is exceptionally vulnerable to 

contamination (Table 4). The profenofos estimated drinking water concentrations were 

modeled for each scenario over 30 years and 100 years, and can be found in Table 4. The 

application rate and interval used in the model for the 30 year period can be found in Table 2,

and the environmental fate values used as inputs for modeling are listed in Table 3. An 

extended weather file was used in all five of the PRZM-GW scenarios to simulate 100 years of 

use because breakthrough was unobserved in each of the scenarios over a 30 year period. 

Breakthrough, for the purposes of PRZM-GW, is defined as the point at which the full 

concentration of the active ingredient applied to the crop is observed to reach the groundwater 

layer. The PRZM-GW model is limited to 500 total applications of the active ingredient over 

the entire time series of the model run. Thus, the number of applications for the 100 year 

modeling period was condensed to 5 applications per season with twice the maximum 

application rate, 1 lb. a.i./A, per application so as not to exceed the capacity of PRZM-GW. 

Breakthrough of profenofos to the groundwater was incomplete over 100 years of application in 

all five of the scenarios.

Table 4. Estimated Ground Water Concentrations of profenofos residues calculated

using the PRZM-GW model over 30 years and 100 years. 

Scenario Daily Peak

(μg/L)

Post Breakthrough 

Average (μg/L)

Average 

Breakthrough Time 

(Days)

NJ/DE – 30 years 0.00106 Incomplete Incomplete

NJ/DE – 100 years 6.38 Incomplete
7

FL – Citrus – 30 years 2.51 Incomplete Incomplete

FL – Citrus – 100 years 16 Incomplete Incomplete

FL – Potato – 30 years 8.79 x 10-5 Incomplete Incomplete

FL – Potato – 100 years 1.96 Incomplete Incomplete

GA – 30 years 3.03 x 10-9 Incomplete Incomplete

GA – 100 years 0.0266 Incomplete Incomplete

NC – 30 years 0.0193 Incomplete Incomplete

NC – 100 years 0.478 Incomplete Incomplete

Abbreviations: NJ/DE=Delmarva Sweet Corn; NC=NC cotton; GA=Georgia Peanuts 1. The PRZM-GW model results can be found in Appendix 2.
8

CITATIONS

Baris, Reubin, et al. 2012. Guidance for Using PRZM-GW in Drinking Water Exposure 

Assessments. Arlington : US EPA, 2012. Guidance.

Bradbury, Steven. 2007. Tier II Drinking Water Exposure Assessment Guidance. Office of 

Pesticide Programs : US EPA, 2007. Guidance.

British Crop Protection Council. 1997. The Pesticide Manual Eleventh Edition. Surrey, UK : 

British Crop Protection Council, 1997.

EFED. 2001. A User's Guide for AgDRIFT 2.01: A Tiered Approach for the Assessment of Spray 

Drift of Pesticides. Environmental Fate and Effects Division : US EPA, Office of 

Pesticide Programs, 2001. User Manual.

EFED 2003. Presentation to Environmental Fate Tech Team, February 13, 2003. Environmental 

Fate and Effects Division : US EPA, Office of Pesticide Programs, 2003.

EFED 2008. Registration Review: Preliminary Problem Formulation for Ecological Risk, 

Environmental Fate, Endangered Species, and Drinking Water Assessment for 

Profenofos. Environmental Fate and Effects Division : US EPA, Office of Pesticide 

Programs, 2008. 348151.

EFED 2009. Guidance for Selecting Input Parameters in Modeling the Environmentl Fate and 

Transport of Pesticides (Version 2.1). Environmental Fate and Effects Division : US 

EPA, Office of Pesticide Programs, 2009. Guidance.

EFED 2014. Development of Community Water System Drinking Water Intake Percent Cropped 

Area Adjustment Factors for use in Drinking Water Exposure Assessments: 2014 Update. 

Environmental Fate and Effects Division : US EPA, Office of Pesticide Programs, 2012. 

Guidance.

EFED 2014. NAFTA Guidance to Calculate Repfresentative Half-life Values and Characterizing 

pesticide Degredation. Office of Pesticide Programs, Environmental Fate and Effects 

Division : US EPA, 2014. Guidance.

EPA, US. 2000. Interim Registration Eligibility Decision (IRED): Profenofos. Washington, 

D.C. : US EPA, Office of Pesticide Programs, 2000.

Fry, Meredith, et al. 2014. Surface Water Concentration Calculator User Manual. 

Environmental Fate and Effects Division, Office of Pesticides : US EPA, 2014. User 

Manual.
9

Health Effects Division (HED). 1995. Profenofos. Outcome of the 7/18/95 Meeting of the HED 

Metabolism Committee. Reregistration Case No. 2540. Chemical No. 111401. 

Washington, D.C. : US EPA, Office of Pesticide Programs, 1995. 21400 MARC.

Mallampalli, Nikhil et al. 2014. Profenofos: General Information on its Use and Alternatives to 

Support Registration Review. August 19. 2014. 
10

Appendix 1 – SWCC Modeling Results: Summary of Water Modeling of Profenofos and 

the USEPA Standard Reservoir

Table 1. Estimated Environmental Concentrations (ppb) Profenofos from the CA cotton scenario.

Peak (1-in-10 yr) 2.51

4-day Avg (1-in-10 yr) 2.19

21-day Avg (1-in-10 yr) 1.77

60-day Avg (1-in-10 yr) 1.05

365-day Avg (1-in-10 yr) 0.182

Entire Simulation Mean 0.174

Table 2. Summary of Model Inputs for Profenofos.

Scenario CAcotton_WirrigSTD

Cropped Area Fraction 1.0

Koc (ml/g) 3890

Water Half-Life (days) @ 25 °C 13.8

Benthic Half-Life (days) @ 25 °C 3.8

Photolysis Half-Life (days) @ 40 °Lat 266

Hydrolysis Half-Life (days) 69.9

Soil Half-Life (days) @ 25 °C 6.9

Foliar Half-Life (days) 35

Molecular Wt 373.63

Vapor Pressure (torr) 9.3E-7

Solubility (mg/l) 20

Figure 1. Yearly Peak Concentrations
11

Table 3. Estimated Environmental Concentrations (ppb) for Profenofos for MS cotton scenario.

Peak (1-in-10 yr) 23.2

4-day Avg (1-in-10 yr) 18.8

21-day Avg (1-in-10 yr) 11.2

60-day Avg (1-in-10 yr) 5.83

365-day Avg (1-in-10 yr) 1.02

Entire Simulation Mean 0.540

Table 4. Summary of Model Inputs for Profenofos.

Scenario MScottonSTD

Cropped Area Fraction 1.0

Koc (ml/g) 3890

Water Half-Life (days) @ 25 °C 13.8

Benthic Half-Life (days) @ 25 °C 3.8

Photolysis Half-Life (days) @ 40 °Lat 266

Hydrolysis Half-Life (days) 69.9

Soil Half-Life (days) @ 25 °C 6.9

Foliar Half-Life (days) 35

Molecular Wt 373.63

Vapor Pressure (torr) 9.3E-7

Solubility (mg/l) 20

Figure 2. Yearly Peak Concentrations
12

Table 5. Estimated Environmental Concentrations (ppb) for Profenofos for NC cotton scenario.

Peak (1-in-10 yr) 21.1

4-day Avg (1-in-10 yr) 18.7

21-day Avg (1-in-10 yr) 10.3

60-day Avg (1-in-10 yr) 5.87

365-day Avg (1-in-10 yr) 0.981

Entire Simulation Mean 0.450

Table 6. Summary of Model Inputs for Profenofos.

Scenario NCcottonSTD

Cropped Area Fraction 1.0

Koc (ml/g) 3890

Water Half-Life (days) @ 25 °C 13.8

Benthic Half-Life (days) @ 25 °C 3.8

Photolysis Half-Life (days) @ 40 °Lat 266

Hydrolysis Half-Life (days) 69.9

Soil Half-Life (days) @ 25 °C 6.9

Foliar Half-Life (days) 35

Molecular Wt 373.63

Vapor Pressure (torr) 9.3E-7

Solubility (mg/l) 20

Figure 3. Yearly Peak Concentrations
13

Appendix 2 – PRZM-GW Modeling Results

Table 1. Groundwater Results for profenofos and the DELMARVA sweet corn - Evesboro loamy 

sand, 30 year Scenario.

Peak Concentration (ppb) 0.00106

Post-Breakthrough Mean Concentration (ppb) Incomplete

Entire Simulation Mean Concentration (ppb) 7.71E-05

Average Breakthrough Time (days) Incomplete

Throughputs 0.2339317

Table 2. Chemical Properties for Groundwater Modeling of profenofos for the DELMARVA sweet 

corn - Evesboro loamy sand, 30 year Scenario.

Koc (ml/g) 3890

Surface Soil Half Life (days) 0

Hydrolysis Half Life (days) 69.9

Diffusion Coefficient Air (cm2/day) 0.032980

Henry's Constant 2.38E-7

Enthalpy (kcal/mol) 8.1

Table 3. Groundwater Results for Profenofos and the DELMARVA sweet corn - Evesboro loamy 

sand, 100 year Scenario.

Peak Concentration (ppb) 6.38

Post-Breakthrough Mean Concentration (ppb) Incomplete

Entire Simulation Mean Concentration (ppb) 1.33

Average Breakthrough Time (days) Incomplete

Throughputs 0.7563034

Table 4. Chemical Properties for Groundwater Modeling of Profenofos for the DELMARVA sweet 

corn - Evesboro loamy sand, 100 year Scenario.

Koc (ml/g) 3890

Surface Soil Half Life (days) 0

Hydrolysis Half Life (days) 69.9

Diffusion Coefficient Air (cm2/day) 0.032980

Henry's Constant 2.38E-7

Enthalpy (kcal/mol) 8.1
14

Table 5. Groundwater Results for Profenofos and the Florida Citrus - FL Central Ridge, Polk 

County - (Tampa) Met File (12842.dvf) - Astatula sand, hrgb A, 30 year Scenario.

Peak Concentration (ppb) 2.51

Post-Breakthrough Mean Concentration (ppb) Incomplete

Entire Simulation Mean Concentration (ppb) 0.482

Average Breakthrough Time (days) Incomplete

Throughputs 0.2748974

Table 6. Chemical Properties for Groundwater Modeling of Profenofos for the Florida Citrus - FL 

Central Ridge, Polk County - (Tampa) Met File (12842.dvf) - Astatula sand, hrgb A, 30 year 

scenario.

Koc (ml/g) 3890

Surface Soil Half Life (days) 0

Hydrolysis Half Life (days) 69.9

Diffusion Coefficient Air (cm2/day) 0.032980

Henry's Constant 2.38E-7

Enthalpy (kcal/mol) 8.1

Table 7. Groundwater Results for Profenofos and the Florida Citrus - FL Central Ridge, Polk 

County - (Tampa) Met File (12842.dvf) - Astatula sand, hrgb A, 100 year Scenario.

Peak Concentration (ppb) 16

Post-Breakthrough Mean Concentration (ppb) Incomplete

Entire Simulation Mean Concentration (ppb) 7.46

Average Breakthrough Time (days) Incomplete

Throughputs 0.9104421

Table 8. Chemical Properties for Groundwater Modeling of Profenofos for the Florida 

Citrus - FL Central Ridge, Polk County - (Tampa) Met File (12842.dvf) - Astatula sand, hrgb A, 

100 year scenario.

Koc (ml/g) 3890

Surface Soil Half Life (days) 0

Hydrolysis Half Life (days) 69.9

Diffusion Coefficient Air (cm2/day) 0.032980

Henry's Constant 2.38E-7

Enthalpy (kcal/mol) 8.1
15

Table 9. Groundwater Results for Profenofos and the FLORIDA - potato - Met File (13889.dvf) 

Jacksonville, 30 year Scenario.

Peak Concentration (ppb) 8.79E-05

Post-Breakthrough Mean Concentration (ppb) Incomplete

Entire Simulation Mean Concentration (ppb) 8.8E-06

Average Breakthrough Time (days) Incomplete

Throughputs 0.1274318

Table 10. Chemical Properties for Groundwater Modeling of Profenofos for the FLORIDA - potato 

- Met File (13889.dvf) Jacksonville, 30 year Scenario..

Koc (ml/g) 3890

Surface Soil Half Life (days) 0

Hydrolysis Half Life (days) 69.9

Diffusion Coefficient Air (cm2/day) 0.032980

Henry's Constant 2.38E-7

Enthalpy (kcal/mol) 8.1

Table 11. Groundwater Results for Profenofos and the FLORIDA - potato - Met File (13889.dvf) 

Jacksonville, 100 year Scenario.

Peak Concentration (ppb) 1.96

Post-Breakthrough Mean Concentration (ppb) Incomplete

Entire Simulation Mean Concentration (ppb) 0.292

Average Breakthrough Time (days) Incomplete

Throughputs 0.4219591

Table 12. Chemical Properties for Groundwater Modeling of Profenofos for the FLORIDA - potato 

- Met File (13889.dvf) Jacksonville, 100 year Scenario.

Koc (ml/g) 3890

Surface Soil Half Life (days) 0

Hydrolysis Half Life (days) 69.9

Diffusion Coefficient Air (cm2/day) 0.032980

Henry's Constant 2.38E-7

Enthalpy (kcal/mol) 8.1
16

Table 13. Groundwater Results for Profenofos and the GA - Southern Coastal Plain, Tifton loamy 

sand – PEANUTS, 30 year Scenario.

Peak Concentration (ppb) 3.03E-09

Post-Breakthrough Mean Concentration (ppb) Incomplete

Entire Simulation Mean Concentration (ppb) 2.27E-10

Average Breakthrough Time (days) Incomplete

Throughputs 0.1667907

Table 14. Chemical Properties for Groundwater Modeling of Profenofos for the GA - Southern 

Coastal Plain, Tifton loamy sand – PEANUTS, 30 year Scenario.

Koc (ml/g) 3890

Surface Soil Half Life (days) 0

Hydrolysis Half Life (days) 69.9

Diffusion Coefficient Air (cm2/day) 0.032980

Henry's Constant 2.38E-7

Enthalpy (kcal/mol) 8.1

Table 15. Groundwater Results for Profenofos and the GA - Southern Coastal Plain, Tifton loamy 

sand – PEANUTS, 100 year Scenario.

Peak Concentration (ppb) 0.0266

Post-Breakthrough Mean Concentration (ppb) Incomplete

Entire Simulation Mean Concentration (ppb) 0.00295

Average Breakthrough Time (days) Incomplete

Throughputs 0.5518569

Table 16. Chemical Properties for Groundwater Modeling of Profenofos for the GA - Southern 

Coastal Plain, Tifton loamy sand – PEANUTS, 100 year Scenario.

Koc (ml/g) 3890

Surface Soil Half Life (days) 0

Hydrolysis Half Life (days) 69.9

Diffusion Coefficient Air (cm2/day) 0.032980

Henry's Constant 2.38E-7

Enthalpy (kcal/mol) 8.1
17

Table 17. Groundwater Results for Profenofos and the NC Eastern Coastal Plain - Norfolk loamy 

sand – Cotton, 30 years Scenario.

Peak Concentration (ppb) 0.0193

Post-Breakthrough Mean Concentration (ppb) Incomplete

Entire Simulation Mean Concentration (ppb) 0.00197

Average Breakthrough Time (days) Incomplete

Throughputs 0.288822

Table 18. Chemical Properties for Groundwater Modeling of Profenofos for the NC Eastern 

Coastal Plain - Norfolk loamy sand – Cotton, 30 years Scenario.

Koc (ml/g) 3890

Surface Soil Half Life (days) 0

Hydrolysis Half Life (days) 69.9

Diffusion Coefficient Air (cm2/day) 0.032980

Henry's Constant 2.38E-7

Enthalpy (kcal/mol) 8.1

Table 19. Groundwater Results for Profenofos and the NC Eastern Coastal Plain - Norfolk loamy 

sand – Cotton, 100 year Scenario.

Peak Concentration (ppb) 0.478

Post-Breakthrough Mean Concentration (ppb) Incomplete

Entire Simulation Mean Concentration (ppb) 0.19

Average Breakthrough Time (days) Incomplete

Throughputs 0.9383513

Table 20. Chemical Properties for Groundwater Modeling of Profenofos for the NC Eastern 

Coastal Plain - Norfolk loamy sand – Cotton, 100 year Scenario.

Koc (ml/g) 3890

Surface Soil Half Life (days) 0

Hydrolysis Half Life (days) 69.9

Diffusion Coefficient Air (cm2/day) 0.032980

Henry's Constant 2.38E-7

Enthalpy (kcal/mol) 8.1