UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON D.C., 20460 

OFFICE OF 

CHEMICAL SAFETY AND 

POLLUTION PREVENTION 

PC Code: 129081 

DP Barcode: D409753 

MEMORANDUM June 11,2014 

Subject: Preliminary Ecological Risk Assessment for the Registration Review of 

Sulfentrazone and Proposed New Uses on Apples 

To: Christina Scheltema, Chemical Review Manager 

Patricia Parrott, Branch Chief 

From: 

Reviewed By: 

Through: 

Risk Management and Implementation Branch 3 

Pesticide Re-evaluation Division (7508P) 

Laura Nallen, Biologist, Minor Use Team 

Barbara Madden, Minor Use Team Leader 

Risk Integration Minor Use, and Emergency Response Branc 

Registration Division (7505C) 

Geoffrey Sinclair, Ph.D., Biologist 

Michael Barrett, Chemist 

Environmental Risk Branch V 

Environmental Fate and Effects Division (7507P) 

Keith Sappington, ~.S .. , Senior Science Adviso;re~- L / ~¥L/ Environmental Risk Branch V ~~ 7 

/// 

EnvironmentaLFate and Effects Division (7507P . ~~II j /f'-

Mah Shamim, Ph.D., Branch Chief /JIJ1p_L 12A~ Environmental Risk Branch V // /Y~v-=-=.__ Environmental Fate and Effects Division (7507P) 

This memorandum transmits the Environmental Fate and Effects Division's (EFED) preliminary 

ecological risk assessment for the registration review of sulfentrazone (PC Code 129081 ), a 

systemic selective herbicide that interferes with chlorophyll and heme. biosynthesis. The 

compound is registered for use to control broadleaf weeds, grasses and sedges. Registered uses 

assessed in this document include ground and aerial application on crop groups such as turf, 

fruits, vegetables, grains, peanuts, com and many other field crops in addition to non-agricultural 

areas with maximum annual rates ranging from 0.125 to 0.375lb a.i. /A. In addition to the 

currently registered uses, this risk assessment also includes an analysis of the proposed new use 

on apples. This risk assessment provides EFED's assessment of the environmental fate, 
2 

terrestrial and aquatic exposure, and ecological risks associated with all registered uses of 

sulfentrazone and proposed uses of sulfentrazone on apples. It also provides an assessment of the 

potential for use of sulfentrazone to cause adverse effects to federally threatened and endangered 

species (hereafter referred to as “listed” species). 

Sulfentrazone can persist for several months or longer in terrestrial environments. Based upon 

its organic carbon partition coefficient and its desorption constant (Koc and Kd, respectively), 

sulfentrazone is expected to be very highly mobile in most soils and is not expected to bind to 

aquatic sediments. Therefore, the chemical is expected to move to surface water via runoff and 

into ground water via leaching. 

The results of this preliminary risk assessment indicate that use of sulfentrazone in ground 

applications (on crop groups such as turf, fruits, vegetables, grains, peanuts, corn and many other 

field crops in addition to non-agricultural area with maximum annual rates ranging from 0.125 to 

0.375lb a.i. /A) poses potential risk to nontarget terrestrial and aquatic plants. Aerial use of 

sulfentrazone at the given proposed uses poses potential risks (for applications to soybeans, 

sugarcane, railroads, highways, roadsides, and pipelines) to nontarget terrestrial and aquatic 

plants. Use of sulfentrazone could potentially result in direct adverse effects to listed species of 

terrestrial and aquatic plants. 

Due to the low acute and chronic toxicity to animals, use of sulfentrazone is expected to pose 

minimal direct risk to terrestrial and aquatic animals, including insects, mammals, aquatic-phase 

amphibians, fish, mollusks, and arthropods. However, use of sulfentrazone poses potential 

chronic risk to birds feeding on short grass, tall grass, broad leaf plants, and arthropods but not 

fruits/pods/seeds. Since birds are surrogates for reptiles and terrestrial-phase amphibians, 

potential chronic risk is assumed for these taxa as well. Sulfentrazone also poses a potential 

chronic risk to estuarine/marine invertebrates. 

As a light dependent peroxidizing herbicide (LDPH) chemical, an uncertainty factor was applied 

to chronic fish toxicity endpoint to account for potential enhanced toxicity of LDPH chemicals to 

animals under ultra violet radiation (i.e., natural sunlight) per EFED policy. There was no 

change in risk conclusions to fish as a result of the use of this factor. This factor is not being 

applied at this time to aquatic invertebrates due to lack of data, so while there is still uncertainty 

for these taxa, the likelihood of adverse effects on taxa such as mollusks and freshwater 

arthropods from exposure to sulfentrazone is presumed to be low. 

Sulfentrazone degradation products are all considered minor (less than 10 percent of applied 

product), and are not believed to contribute significantly to the ecological risks. 

The risks associated with potential direct effects due to applications of sulfentrazone are 

presented below. The distance from edge of field of risk to non-target terrestrial plants is based 

on AgDrift prediction of spray drift. 

 
3 

Listed and Non-listed 

Plant Taxon Potential Direct Effects 

Terrestrial and semiaquatic plants – 

monocots and dicots 

RQs exceeded the LOC for all exposure scenarios. Using TerrPlant to depict 

exposure for dry and semi-aquatic terrestrial habitats, RQs were estimated for 

exposure (including runoff and spray drift) to non-target plants adjacent to the 

site of application. Dicots were the more sensitive species; for application rates 

of 0.19 lb ai/A, RQs for non-target plants range from 1 – 17, and RQs ranged 

from 2 to 32 for application rates of 0.375 lb ai / A. For aerial applications RQs 

ranged from 6 to 43 for listed species. 

 

 

For exposure from drift alone, an analysis was conducted to estimate the distance 

(using AgDrift) from the site of application needed in order to be below the LOC. 

Below is a subset of the analysis (dicots are the more sensitive species) that 

illustrates the influence on the distance needed to be below the LOC when 

considering coarser droplet sizes, or the boom height for a ground application. 

 

 

 Application Rate 

 (lb a.i./A) 

Crop, Timing, 

Application Rate 

(lb a.i./A)

Application 

Method Droplet Size

Distance 

from Field

( feet)

Terrestrial and semiaquatic plants dicots 

Many Uses 0.375 Aerial 

Coarse – very 

coarse >1,000 

Medium - coarse >1,000 

Fine – medium >1,000 

Very fine - Fine >1,000 

Many Uses Ground, low boom Very fine - Fine 847 

0.375 Ground, high boom Fine – medium >1,000 

Terrestrial and semiaquatic plants monocots 

Many Uses 0.375 Aerial 

Coarse – very 

coarse 141 

Medium - coarse 210 

Fine – medium 620 

Very fine - Fine >1,000 

Many Uses Ground, low boom Very fine - Fine 56 

0.375 Ground, high boom Fine – medium 154 

Aquatic plants 

RQs in clear waters range from 0.6 to 1 and only exceed the LOC for risk to 

listed non-vascular plant species. RQs in shaded or turbid waters range up to 1.8 

and exceed the LOC of 1.0 for both vascular and non-vascular taxa. 
4 

Listed and Non-listed 

Animal Taxon 

Potential Direct Effects 

Acute Notes Chronic Notes 

Terrestrial invertebrates 

No 

effect ND1

1

 ND signifies that no 

data were available to 

assess the risk. 

2

Terrestrial-phase 

reptiles and 

amphibians based 

on chronic risks to 

birds. 

Mammals 

No 

effect No effect 

Birds 

No 

effect Yes 

Reptiles 

No 

effect Yes2

Amphibians 

No 

effect Yes2

Freshwater fish 

No 

effect No effect 

Freshwater invertebrates 

No 

effect No effect 

Mollusks 

No 

effect ND1

Estuarine/marine fish 

No 

effect No effect

Estuarine/marine 

invertebrates 

No 

effect Yes 

Because of the potential for adverse effects to plants, the use of sulfentrazone also may result in 

modification of primary constituent elements of designated critical habitats for listed species, 

where such designations have been made. 

Additional Considerations for Listed Species 

The EPA along with the U.S. Fish & Wildlife Service (USFWS), the National Marine Fisheries 

Service (NMFS) (collectively, the Services), and the U.S. Department of Agriculture (USDA), 

released a summary of their implementation plan for assessing risks of pesticides to listed species 

ahead of the stakeholder workshop held on November 15, 2013. This plan was developed in 

response to the National Academy of Sciences’ (NAS) recommendations, including a common 

approach to risk assessment as a way of addressing scientific differences between EPA and the 

Services. During the workshop, the agencies received feedback from the public on the interim 

scientific approaches that were developed as part of the initial implementation of the NAS 

recommendations. These approaches will be jointly implemented and vetted as part of a phased, 

iterative process. Once fully vetted, EPA will further refine the listed species effects 

determination portion of this risk assessment. 

To make effects determinations for individual listed species, useful refinements may include, but 

are not necessarily limited to, analyses of: 1) more detailed, species-specific ecological and 

biological data; 2) more detailed and accurate information on sulfentrazone use patterns; and 3) 

sub-county level spatial proximity data for the co-occurrence of potential effects areas and listed 

species and any designated critical habitat. Examples of such refinements are described below. 
5 

EFED is currently developing tools that are expected to further refine the assessment and are 

designed to support effects determinations for individual listed species and their designated 

critical habitats (where applicable). Scientific information obtained from the Services, and from 

other reliable sources is being collated by EFED to address all currently listed species. This 

information is being stored in an Office of Pesticide Programs (OPP) Pesticide Registration 

Information SysteM (PRISM) listed species knowledgebase. The listed species knowledgebase 

consists of an information repository that houses biological and behavioral information relevant 

to individual species (e.g., habitat, diet, and life history, including specific temporal and spatial 

associations) and a document repository that contains supporting documents (e.g., USFWS 

recovery plans) and electronic information (e.g., Geographic Information System (GIS) data 

files). For terrestrial taxa, biological information relevant to the assessment (e.g., diet and body 

weight) will be used to parameterize exposure estimates using a method consistent with currently 

used methods in the T-REX and T-HERPS models. 

Refinements will also include more detailed analyses of the registered uses and specific use 

patterns that result in either “Likely to Adversely Affect” (LAA) or “Not Likely to Adversely 

Affect” (NLAA) determinations for listed species. The analyses may include more information 

on where, when, and how sulfentrazone is used on all use sites. Actual usage data (when 

available) and national land-cover datasets that indicate potential use sites [e.g., National Land 

Cover Dataset (NLCD), Cropland Data Layer (CDL)] may be used to support a more refined 

analysis of where sulfentrazone is reasonably expected to be used. Similarly, refinements on the 

timing of applications and a more in-depth exploration of agronomic practices for FPE may be 

included as part of the refinement. 

The refinements based on individual species data; additional, detailed usage information, when 

available; and developments based upon recommendations from the NAS report are expected to 

help EPA more accurately identify potential areas of effect, and to better inform effects and 

habitat determinations for listed species and any designated critical habitats. 

 
6 

Preliminary Ecological Risk Assessment for the 

Registration Review of Sulfentrazone

(CAS Reg. No. 122836-35-5; USEPA PC Code: 129081) 

Prepared by: 

Geoffrey Sinclair, Ph.D., Biologist 

Michael Barrett, Senior Chemist 

Reviewed by: 

Keith Sappington, M.S., Senior Science Advisor 

Mohammed Ruhman, Ph.D., Senior Agronomist 

Approved by: 

Mah Shamim, Ph.D., Branch Chief 

Environmental Risk Branch V 

Environmental Fate and Effects Division 

Office of Pesticide Programs 

U.S. Environmental Protection Agency 

June 2014

Office of Chemical Safety and 

Pollution Prevention
7 

Table of Contents 

I. EXECUTIVE SUMMARY .............................................................................................. 12

A. Purpose of Assessment ......................................................................................... 12

B. Nature of the Stressor ............................................................................................ 12

C. Summary of Effects and Risk Conclusions .......................................................... 12

II. PROBLEM FORMULATION ......................................................................................... 15

A. Pesticide Type, Class, and Mode of Action .......................................................... 15

B. Pesticide Use and Usage ....................................................................................... 15

1. Pesticide Labeled Use ............................................................................... 15

2. Pesticide Usage ......................................................................................... 22

C. Previous Ecological Risk Assessments and Evaluations ...................................... 23

D. Assessment Endpoints .......................................................................................... 24

E. Analysis Plan and Conceptual Models ................................................................. 25

1. Measures to Evaluate Risk Hypotheses .................................................... 25

2. Conceptual Model ..................................................................................... 25

3. Risk Hypothesis ........................................................................................ 27

III. ANALYSIS ....................................................................................................................... 29

A. Measures of Exposure ........................................................................................... 29

1. Environmental Fate and Modeling Input Parameters ............................... 29

2. Environmental Fate Summary .................................................................. 32

3. Monitoring Data ........................................................................................ 37

B. Exposure Estimates for Non-target Aquatic Animals and Plants ......................... 40

C. Ecological Effects Characterization ...................................................................... 47

1. Aquatic Animals ....................................................................................... 47

2. Aquatic Plants ........................................................................................... 50

3. Terrestrial Animals ................................................................................... 51

4. Terrestrial Plants ....................................................................................... 54

IV. RISK ESTIMATION ........................................................................................................ 55

A. Non-target Terrestrial Animals ............................................................................. 58

B. Non-target Terrestrial Plants ................................................................................. 61

C. Review of Incident Data ....................................................................................... 68

D. Probit Slope Response Analysis of LOC Values and Acute RQ Values .............. 68

V. RISK DESCRIPTION ...................................................................................................... 69

A. Risk Characterization ............................................................................................ 69

1. Summary of Risk ...................................................................................... 69

2. Risk to Aquatic and Terrestrial Animals .................................................. 69

3. Risk to Terrestrial and Aquatic Plants ...................................................... 70

4. Risk to Endangered Species ...................................................................... 71

B. Assumptions and Limitations ............................................................................... 72

1. Endocrine Disruption ................................................................................ 72

2. Uncertainties Related to Data Limitations ................................................ 73

3. Routes of Exposure ................................................................................... 74

4. Species sensitivity ..................................................................................... 74

5. Sub-lethal Effects ...................................................................................... 76

6. Other Uncertainties in Risk Conclusions .................................................. 76

VI. RISK CONCLUSIONS .................................................................................................... 77
8 

VII. REFERENCES ................................................................................................................. 79

VIII. Appendices ........................................................................................................................ 81

A. Bibliography ......................................................................................................... 81

1. Toxicity Studies ........................................................................................ 81

2. Environmental Fate Studies ...................................................................... 85

B. Pesticide Products Registered in the United States that Contain Sulfentrazone ... 91

C. Chemical Names and Structures ........................................................................... 96

D. ECOSAR Results for Property Prediction of Sulfentrazone and its Most 

Prominent Degradates ......................................................................................... 100

1. Parent Sulfentrazone ............................................................................... 100

2. Sulfentrazone 3-carboxylic acid (SCA) .................................................. 102

E. Aquatic Exposure Model Input and Output ........................................................ 105

1. List of Surface Water Standard Scenarios Used ..................................... 105

2. Sample Model Input Files ....................................................................... 106

3. Sample Model Output Files .................................................................... 123

F. Terrestrial Exposure Model Results .................................................................... 126

1. T-Rex Run for Spray Applications ......................................................... 126

2. TerrPlant ................................................................................................. 133

G. Ecological Incident Reports for Sulfentrazone ................................................... 134

H. ECOTOX Database Bibliography for Sulfentrazone .......................................... 135

 
9 

Table of Figures 

Figure 1. Chemical Structure of Sulfentrazone ...................................................................... 15

Figure 2. Conceptual model depicting stressors, exposure pathways, and potential effects 

to aquatic animals and plants from the use of Sulfentrazone. ................................................ 26

Figure 3. Conceptual model depicting stressors, exposure pathways, and potential effects 

to terrestrial animals and plants from the use of sulfentrazone. ............................................ 27

 
10 

Table of Tables 

Table 1. Risks Associated with Potential Direct Effects Due to the Applications of 

Sulfentrazone. The distance from edge of field of Risk to non-target terrestrial plants is 

based on AgDrift prediction of spray drift. .............................................................................. 13

Table 2. Application Information for Registered Use Sites and the Apples Proposed Use of 

Sulfentrazone . ............................................................................................................................. 18

Table 3. Screening Level Estimates of Agricultural Uses of Sulfentrazone (February 27, 

2013)1,2 .......................................................................................................................................... 22

Table 4. Physical/chemical Properties and Environmental Fate Properties of 

Sulfentrazone. .............................................................................................................................. 29

Table 5. Mobility classification of pesticides according to the McCall system. ..................... 36

Table 6. Description of “95th percentile” ground-water vulnerability site. .......................... 37

Table 7. Description of “85th percentile ” ground-water vulnerability site. ......................... 37

Table 8. Description of “75th percentile ” ground-water vulnerability site. ......................... 38

Table 9. . Description of “>95th percentile ” ground-water vulnerability site. ..................... 38

Table 10. Maximum observed concentrations of sulfentrazone and its acid degradate in 

shallow groundwater below or immediately downgradient of treated fields at four sites. .. 39

Table 11. Tier 2 Surface Water Estimated Environmental Concentrations (EECs) for 

Registered Uses of Sulfentrazone. ............................................................................................. 41

Table 12. Tier 2.5 Surface EECs for Sulfentrazone: Effect of Different Assumptions of 

Light Availability in Farm Pond for a High Exposure Use. ................................................... 45

Table 13. Input Parameters for T-REX Modeling for All Uses of Sulfentrazone................ 46

Table 14. Dietary-Based Sulfentrazone EEC Values for 0.375 lb a.i. lb /A application rate.

....................................................................................................................................................... 46

Table 15. Avian and Mammalian Dose-Based Sulfentrazone Upper-Bound EEC Values . 46

Table 16. Acute Toxicity of Sulfentrazone to Aquatic Animals. (Bolded values represent 

most sensitive value used for estimating RQs.) ........................................................................ 48

Table 17. Chronic Toxicity of Sulfentrazone to Aquatic Animals ......................................... 49

Table 18. Acute Toxicity Values of Sulfentrazone to Aquatic Plants.................................... 51

Table 19. Acute Toxicity of sulfentrazone to Terrestrial Species .......................................... 52

Table 20. Chronic Toxicity of Sulfentrazone to Terrestrial Animals ................................... 54

Table 21. Toxicity of Sulfentrazone to Terrestrial Plants. (Bolded values are the most 

sensitive endpoints used for assessing risk to terrestrial plants.) ........................................... 55

Table 22. Acute and Chronic RQs for Fish and Aquatic Invertebrates ............................... 56

Table 23. RQs for Aquatic Plants and Algae ........................................................................... 57

Table 24. Acute and Chronic Dietary-Based RQs for Birds .................................................. 59

Table 25. Acute Dose-Based RQs for Birds ............................................................................. 59

Table 26. Chronic Dietary-Based RQs for Mammals............................................................. 60

Table 27. Acute and Chronic Dose-Based RQs for Mammals ............................................... 60

Table 28. Dietary and contact RQs for honey bees. ................................................................. 61

Table 29. RQs for Risk to Nontarget Terrestrial Plants from Use of Sulfentrazone for 

ground applications. ................................................................................................................... 61

Table 30. RQs for Risk to Nontarget Terrestrial Plants from Use of Sulfentrazone for 

aerial applications. ...................................................................................................................... 63
11 

Table 31. Distance from Edge of Field of Risk to non-target terrestrial Plants, Based on 

AgDrift Prediction of Spray Drift with a very fine to fine particle size and a high boom 

dispersal. ...................................................................................................................................... 65

Table 32. Distance from Edge of Field of Risk to Listed Terrestrial Plants, Based on 

AgDrift Prediction of Spray Drift with a fine to medium/coarse particle size and a high 

boom dispersal. ............................................................................................................................ 66

Table 33. Distance from Edge of Field of Risk to non-target terrestrial plants, based on 

AgDrift Prediction of Spray Drift with aerial application with particle size scenarios of 

very fine to fine and fine to medium.......................................................................................... 66

Table 34. Distance from Edge of Field of Risk to Listed Terrestrial Plants, Based on 

AgDrift Prediction of Spray Drift with aerial application with particle size scenarios of 

medium to coarse and coarse to very coarse. ........................................................................... 67

Table 35. Percentage of EEC or RQ for the Specified Dietary Items and Size Classes as 

Compared to the EEC or RQ for The Most Sensitive Dietary Items (Short Grass) and Size 

Class (Small Bird or Small Mammal) ....................................................................................... 75

Table 36. Potential Non-listed and Listed Species Risks Associated with Potential Direct or 

Indirect Effects Due to the Applications of Sulfentrazone .................................................... 77

Table 37. Structures and properties of sulfentrazone and its degradates. ............................ 96

 
12 

I. EXECUTIVE SUMMARY 

A. Purpose of Assessment 

The purpose of this registration review assessment is to evaluate the potential risks of current 

registered agricultural and non-agricultural uses and a proposed new use on apples of the 

herbicide sulfentrazone to non-target organisms, including federally listed endangered and 

threatened (listed) species. This risk assessment incorporates the available exposure and effects 

data and the most current modeling and risk methodologies. 

B. Nature of the Stressor 

Sulfentrazone, CAS Name: N-[2,4-dichloro-5-[4-(difluoromethyl) 4,5-dihydro-3-methyl-5-oxo1H-1,2,4-triazol-1-yl]phenyl] methanesulfonamide (CAS Number 122836-35-5;PC Code of 

129081). Sulfentrazone is a systemic selective herbicide and belongs to the phenyl pyrazole 

class of chemicals called protox inhibitors. The chemical inhibits an enzyme in a plant’s 

chloroplasts (protoporphyrinogen oxidase) and is characterized as a light-dependent peroxidizing 

herbicide (LDPH) which acts by blocking heme (in animals) and chlorophyll (in plants) 

biosynthesis resulting in an endogenous accumulation of photo-toxic porphyrins (Birchfield and 

Casida 1997). The accumulation of porphyrins (e.g., porphyria) can lead to toxicosis in the 

absence of light. Light however can enhance the toxicity as ultra violet light (uV) increases the 

formation of reactive free radicals (Matringe et al. 1989). LDPHs may be more toxic when 

exposed to natural sunlight, such as exposure conditions in the field (US EPA 2010). 

Sulfentrazone has an environmental degradate that might form in major amounts over a period of 

years but it is not confirmed to be major in most environmental fate studies because of the high 

persistence of parent: Sulfentrazone 3-carboxylic acid (also known as SCA or FMC 129427) (1-

[2,4-Dichloro-5-(N-(methylsulfonyl) amino) phenyl]-4-difluoromethyl-4,5-dihydro-5-oxo-1H1,2,4-triazole-3-carboxylic acid ). However, exposure to this degradate is not expected to exhibit 

toxicity in plants or animals similar to that of the parent compound (EcoSar results are in 

Appendix D.)

C. Summary of Effects and Risk Conclusions 

The results of this preliminary risk assessment indicate that the registered uses of sulfentrazone 

and proposed use on apples have broad potential for direct adverse effects to listed and non-listed 

species of aquatic and terrestrial plants (Table 1). The high persistence and high mobility of 

sulfentrazone exacerbates the risk to non-target plants. 

The likelihood of adverse effects to terrestrial animals from direct exposure is expected to be low 

(i.e., below Agency levels of risk concern) except for chronic risk to estuarine/marine 

invertebrates and chronic risk to birds (as well as terrestrial-phase amphibians and reptiles for 

which birds serve as surrogates). There is also a potential for indirect effects to terrestrial and 

aquatic animals due to reduction in primary productivity and habitat. There is uncertainty when 

assessing the potential risk to aquatic animals from direct effects due to sulfentrazone being an 

LDPH and the potential of LDPHs to exhibit enhanced toxicity in the presence of ultraviolet 
13 

light. Following EFED guidance for LDPH chemicals, an interim 29X toxicity adjustment factor 

was applied to chronic toxicity estimates obtained from a fish early life stage study but was not 

applied to aquatic invertebrates due to lack of available data at this time (U.S. EPA, 2010). 

 

Toxicity data on sulfentrazone indicate that it is practically nontoxic to birds, mammals, and 

young adult bees on an acute exposure basis. Sulfentrazone is slightly to practically non-toxic to 

freshwater fish with the bluegill (Lepomis macrochirus) being most sensitive with an LC50 of 

93.8 mg a.i. / L. Sulfentrazone is practically non-toxic to marine fish on an acute exposure basis. 

Prior to incorporation of the previously mentioned adjustment factor, the freshwater fish early 

life stage toxicity test resulted in reduced survival (NOAEC = 2.95 mg a.i. / L). 

Sulfentrazone was slightly toxic to highly toxic to freshwater invertebrates and estuarine/marine 

invertebrates on an acute exposure basis with reported LC50 values of 60.4 and 1.0 mg a.i. / L, 

respectively. The freshwater invertebrate life cycle toxicity test resulted in a NOAEC of 0.2 mg 

a.i./L based on the number of dead/immobile daphnids.

As expected for an herbicide, sulfentrazone is toxic to terrestrial and aquatic plants. In seedling 

emergence and vegetative vigor tests, 25% inhibition (IC25) of growth has been shown to occur 

in sensitive terrestrial plants at exposure levels equivalent to application rates of 0.00052 to 

0.023 lb a.i./A with cucumber (Cucumis sativus) being the most sensitive and oat (Avena sativa ) 

being the least sensitive. NOAEC values are as low as 0.00044 lb a.i./A for the dicotyledenous 

(dicot) cucumber. In aquatic plant tests, both algae (non-vascular) and aquatic vascular plants 

have been shown to be sensitive to sulfentrazone. Fifty percent inhibition (IC50) of growth in 

nonvascular aquatic plants is predicted at a concentration of 0.031 mg a.i./L, and 50% inhibition 

of growth of the vascular aquatic plant duckweed (Lemna gibba) was measured at 0.029 mg 

a.i./L. The NOAEC was 0.016 mg a.i./L for nonvascular plants and 0.019 mg a.i./L for vascular 

plants. 

Risks associated with potential direct effects due to applications of sulfentrazone are summarized 

in Table 1. 

Table 1. Risks Associated with Potential Direct Effects Due to the Applications of 

Sulfentrazone. The distance from edge of field of Risk to non-target terrestrial plants is 

based on AgDrift prediction of spray drift. 

Listed and Non-listed 

Plant Taxon Potential Direct Effects 

Terrestrial and semiaquatic plants – monocots 

and dicots 

RQs exceeded the LOC for all exposure scenarios. Using TerrPlant to depict 

exposure for dry and semi-aquatic terrestrial habitats, RQs were estimated for 

exposure (including runoff and spray drift) to non-target plants adjacent to the 

site of application. Dicots were the more sensitive species; for application rates 

of 0.19 lb ai/A, RQs for nontarget plants range from 1 – 17, and RQs ranged 

from 2 to 32 for application rates of 0.375 lb ai / A. For aerial applications RQs 

ranged from 6 to 43 for listed species. For additional details, refer to Table 31. 

 
14 

 

For exposure from drift alone, an analysis was conducted to estimate the distance 

(using AgDrift) from the site of application needed in order to be below the 

LOC. Below is a subset of the analysis (monocots are the more sensitive species) 

that illustrates the influence on the distance needed to be below the LOC when 

considering coarser droplet sizes, or the boom height for a ground application. 

For additional details, refer to Table 32, Table 33, Table 34 and, Table 35. 

 Crop, Timing, 

Application 

Method Droplet Size 

Distance 

from 

Field 

( feet) 

 Application Rate 

 (lb a.i./A) 

Terrestrial and semiaquatic plants dicots 

Many Uses 0.375 Aerial 

Coarse – very coarse >1,000 

Medium - coarse >1,000 

Fine – medium >1,000 

Very fine - Fine >1,000 

Many Uses Ground, low boom Very fine - Fine 847 

0.375 Ground, high boom Fine – medium >1,000 

Terrestrial and semiaquatic plants monocots 

Many Uses 0.375 Aerial 

Coarse – very coarse 141 

Medium - coarse 210 

Fine – medium 620 

Very fine - Fine >1,000 

Many Uses Ground, low boom Very fine - Fine 56 

0.375 Ground, high boom Fine – medium 154 

Aquatic plants 

RQs in clear waters range from 0.6 to 1 and only exceed the LOC for risk to 

listed non-vascular plant species. RQs in shaded or turbid waters range up to 1.8 

and exceed the LOC of 1.0 for both vascular and non-vascular taxa. 

Listed and Non-listed 

Animal Taxon 

Potential Direct Effects 

Acute Notes Chronic Notes 

Terrestrial invertebrates 

No 

effect ND1

1

 ND signifies 

that no data were 

available to 

assess the risk. 

2

Terrestrialphase 

amphibians 

based on 

chronic risks 

to birds. 

Mammals 

No 

effect No effect 

Birds 

No 

effect Yes 

Reptiles 

No 

effect Yes 

Amphibians 

No 

effect Yes2

Freshwater fish 

No 

effect No effect 

Freshwater invertebrates 

No 

effect No effect 
15 

Mollusks 

No 

effect ND1

Estuarine/marine fish 

No 

effect No effect

Estuarine/marine 

invertebrates 

No 

effect Yes 

II. PROBLEM FORMULATION 

A. Pesticide Type, Class, and Mode of Action 

Sulfentrazone is classified as a protoporphyrinogen oxidase inhibitor (“PPO” or “protox” 

inhibitor) and is a light dependent peroxidizing herbicide (LDPH) in the phenyl (aryl) pyrazole 

structural class. Protoporphyrinogen oxidase (protox) is the last common enzyme in the heme 

and chlorophyll biosynthetic pathways (Matringe, et.al, 1989). In plants, protox inhibition by 

LPDHs results in rapid accumulation of protoporphyrin IX. In the presence of ultraviolet light, 

protoporphyrin IX causes lipid membrane peroxidation leading to a rapid loss of turgidity and 

foliar burns in plants. Protox exists in both plants and animals and the enzyme has been shown to 

be highly sensitive to many LDPHs (Birchfield and Casida, 1997). 

Figure 1. Chemical Structure of Sulfentrazone 

B. Pesticide Use and Usage 

1. Pesticide Labeled Use 

Sulfentrazone is a systemic selective herbicide for control of certain broadleaf weeds, grasses 

and sedges. Currently, this risk assessment focuses on exposures and potential effects from 

exposure to sulfentrazone as the sole stressor. As of March 26, 2013, sulfentrazone is an active 

ingredient in 132 products registered in the United States (Appendix B). Application rates and 

specifications by use site are summarized in Table 2.

 
16 

Products containing sulfentrazone are formulated as water-dispersible granules, granules, 

flowable concentrates, or emulsifiable concentrates. Products may be applied to fields pre-plant 

incorporated, pre-plant surface, or pre-emergence treatments. Products containing sulfentrazone 

are often formulated together with other herbicidal active ingredients. 

Some product labels for some use sites implicitly allow only one or two applications (because of 

the difference or lack of difference between the maximum single or annual application rates) per 

year or crop season. Annual or seasonal maximum rates are consistently specified, and 

depending on the use site are set at 0.375 lb a.i./A or less (Table 3). 

A notable limitation on sites where sulfentrazone can be applied is part of a Groundwater 

advisory on product labels: 

“Do not use on coarse soils classified as sand which have less than 1 % 

organic matter” 

Additionally, on some product labels, for use sites where the maximum single application rate is 

at its highest level (0.375 lb ai/A), the allowable application rate generally varies by soil texture, 

topsoil organic matter content and soil pH. An example from the Spartan 4F label is provided in 

Table 2. 

Table 2. Example of Sulfentrazone Use Rate Variance by Soil Characteristics (from Spartan 

4F label). 

Definition of coarse, medium, and fine texture soils: 

Example use rate tables by soil texture, organic matter content, and pH. 

(Above taken from the sulfentrazone Spartan 4F label; 12 ounces formulated product equates 

to 0.375 lb sulfentrazone active ingredient per acre.) 
17 

 
Table 3. Application Information for Registered Use Sites and the Apples Proposed Use of Sulfentrazone. 

Crop or Non-Agricultural 

Use Site1

Single 

Min, lb 

ai/A 

product; 

All sites 

Rates 

vary by 

soil 

texture / 

% 

Organic 

Matter 

Max # 

Applic. 

Aerial 

application? 

Minim. 

Interval 

(days) 

PHI, days 

Maxim. 

single 

(1st) 

aplica., lb 

ai/A 

Maxim. 

Annual 

Rate, lb 

ai/A 

Brassica leafy greens 0.070 Yes NS2 NS2 NS2 NS2 0.2000 0.2200 Corn (GMO tolerant to PPO herbicides) 0.094 Yes NS2 NS2 NS2 NS2 0.1875 0.3750 Corn (GMO tolerant to PPO herbicides) 0.141 Yes NS2 NS2 NS2 NS2 0.2500 0.3750 Cowpeas, succulent (TN) 0.070 Yes NS2 NS2 NS2 NS2 0.1875 0.1875 Dry beans & peas (ND SD MT MN WY CO NE KS Wl Ml OR ID WA OR) 

0.070 Yes NS2 NS2 NS2 NS2 0.2500 0.2500 

Fallow, Postharv. Burndown 0.094 Yes NS2 NS2 NS2 NS2 0.2500 0.2500 Horseradish ((MN ND SD MT CO NE WY ID WA OR Wl Ml) 0.070 Yes NS2 NS2 NS2 NS2 0.2500 0.2500 Lima beans succul. (TN) 0.070 Yes NS2 NS2 NS2 NS2 0.1875 0.1875 

1 Limitations to crop strains or certain geographical areas (states) are given in parenthesis. 2 NS: Not specified 
Crop or Non-Agricultural 

Use Site1

Single 

Min, lb 

ai/A 

product; 

All sites 

Rates 

vary by 

soil 

texture / 

% 

Organic 

Matter 

Max # 

Applic. 

Aerial 

application? 

Minim. 

Interval 

(days) 

PHI, days 

Maxim. 

single 

(1st) 

aplica., lb 

ai/A 

Maxim. 

Annual 

Rate, lb 

ai/A 

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 subgroup 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 (proposed use) 0.125 No 2*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 head & stem (Broccoli, Cabbage 0.070 Yes NS NS NS NS 0.3750 0.3750 

2 * = Implied, but not explicitly stated on product labels. 
Crop or Non-Agricultural 

Use Site1

Single 

Min, lb 

ai/A 

product; 

All sites 

Rates 

vary by 

soil 

texture / 

% 

Organic 

Matter 

Max # 

Applic. 

Aerial 

application? 

Minim. 

Interval 

(days) 

PHI, days 

Maxim. 

single 

(1st) 

aplica., lb 

ai/A 

Maxim. 

Annual 

Rate, lb 

ai/A 

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 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 Rights-ofWay, Industrial Areas, Fence Rows, and Other listed Noncrop 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 
Crop or Non-Agricultural 

Use Site1

Single 

Min, lb 

ai/A 

product; 

All sites 

Rates 

vary by 

soil 

texture / 

% 

Organic 

Matter 

Max # 

Applic. 

Aerial 

application? 

Minim. 

Interval 

(days) 

PHI, days 

Maxim. 

single 

(1st) 

aplica., lb 

ai/A 

Maxim. 

Annual 

Rate, lb 

ai/A 

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 0.37503

3 Implied; some labels need to be clarified regarding the maximum annual rate. 
22 

2. Pesticide Usage 

EPA’s Biological and Economic Analysis Division (BEAD) provided an analysis of nationallevel usage information using state-level usage data obtained from various public and proprietary 

sources. Table 4 provides 2013 estimates of the usage of sulfentrazone on various crops. The 

largest usage of sulfentrazone is on soybeans, with 300,000 lbs applied in the United States 

annually. Other major uses include sunflowers and tobacco in which 50% and 45% of the 

treated crop are treated with sulfentrazone. Fifteen of the eighteen ecological incidents, all 

involving plants, reported to the EIIS database (Appendix G) were associated with uses on 

soybeans. 

Table 4. Screening Level Estimates of Agricultural Uses of Sulfentrazone (February 27, 

2013)1,2 

Crop Lbs. A.I. Percent Crop Treated 

Avg. Max. 

1 Alfalfa 1,000 <1 <2.5 

2 Asparagus 1,000 10 20 

3 Cabbage <500 <2.5 5 

4 Corn 2,000 <1 <2.5 

5 Dry Beans/Peas 30,000 10 20 

6 Fallow 3,000 <1 <2.5 

7 Peanuts 1,000 <1 <2.5 

8 Peas, Green <500 <1 <2.5 

9 Potatoes 4,000 <2.5 <2.5 

10 Pumpkins+ <500 <2.5 5 

11 Rice 4,000 <1 <2.5 

12 Soybeans 300,000 5 10 

13 Strawberries 1,000 5 10 

14 Sugarcane 3,000 <1 <2.5 

15 Sunflowers 100,000 50 65 

16 Tobacco 30,000 45 60 

17 Watermelons <500 <2.5 <2.5 

18 Wheat 3,000 <1 <2.5 

All numbers are rounded. 

<500: indicates less than 500 pounds of active ingredient. 

 <2.5: indicates less than 2.5 percent of crop is treated. 

 <1: indicates less than 1 percent of crop is treated. 

 +: Crops not known to be listed on active end use product registrations or as Section 18 emergency 

exemptions when this report was run. 

 

SLUA data sources include: 
23 

USDA-NASS (United States Department of Agriculture's National Agricultural Statistics Service) 

Private Pesticide Market Research 

These results reflect amalgamated data developed by the Agency and are releasable to the public. 

According to the Label Use Information System (LUIS) reports, sulfentrazone can be applied 

under the following use patterns: terrestrial food/feed/non-food, and residential outdoor. Under 

the food/feed uses, sulfentrazone can be applied to asparagus, beans, cabbage, catjang, corn, 

cowpea, garbanzos, guar, horseradish, lentils, mint, peanuts, peas, peppermint, potato, soybeans, 

spearmint, sugarcane, and sunflower. Under the non-food and non-feed uses, sulfentrazone can 

be applied to agricultural and nonagricultural rights-of-way/fences/hedgerows, agricultural and 

nonagricultural uncultivated areas, agricultural/farm premises, airport/landing fields, commercial 

storages/warehouses premises, commercial/industrial lawns, commercial/institutional/industrial 

premises, golf course turf, household/domestic dwellings outdoor premises, industrial areas, 

ornamental shade trees/herbaceous plants/lawns/turf/ nonflowering plants/ sod farms/woody 

shrubs/ vines, paths/ patios, private paved roads/ sidewalks, recreation lawns, residential lawns, 

sewage disposal areas, and tobacco. 

Sulfentrazone can be applied by ground equipment, and also, for most use sites, by aerial 

equipment. 

Most of the corresponding maximum application rates, application intervals, and seasonal 

application rates for other food/feed uses were not reported. These parameters are necessary for 

modeling and conservative assumptions were made when necessary information could not be 

obtained. 

The highest single application rate on the non-food/non-feed uses is apparently intended to be 

0.375 lb ai/year on lawns, turf, rights-of-way, industrial areas, and other non-crop sites. 

However, the language on the labels regarding the annual limits is not consistently explicitly 

stated for all of these uses. A general statement to this effect on the Sulfentrazone 4F ROW and 

other labels for non-crop would clarify that the 0.375 lb ai/Acre annual limit on sulfentrazone 

applications is intended for all use sites. Although sulfentrazone can be applied two times with 

an application interval of 30 days to residential lawns, the maximum yearly rate is not reported. 

If the labels are not clearly standardized to limit the annual use to 0.375 lb ai/Ac for lawns and 

other sites with vague label language the Agency’s risk assessments will need to be revised to 

assume that much higher annual rates of application could occur at these sites. 

C. Previous Ecological Risk Assessments and Evaluations

The most recent ecological risk assessment was conducted on July 1, 2008 for the uses on 

Head/Stem Brassica Subgroup 5A, Leafy Greens Subgroup 5B, Melon Subgroup 9A, Fruiting 

Vegetable Group 8, Okra, Succulent Pea, Strawberry and Tuberous/Corm Vegetable Subgroup 

1C (US EPA 2008, DP 349322). Based on previous assessments, sulfentrazone poses little risk 

to most terrestrial and aquatic animals tested. However, for terrestrial plants adjacent to 

treatment sites and in semi-aquatic areas, risk quotients (RQs) exceeded LOCs for 

monocotyledonous (monocots) and dicotyledenous (dicots) plants. Also, since sulfentrazone 

may exhibit photo- and phyto-toxicity, and RQs exceeded LOCs, listed and non-listed aquatic 
24 

plant species are potentially at additional risk. There is also the potential for indirect effects on 

non-target animal species due to the effects on primary productivity and habitat (e.g., depletion 

of food sources and habitat).

Previously, the most recently updated drinking water assessment was in 2012 (DP Barcode 

D393777 and D393770; dated April 25, 2012). This assessment has now been comprehensively 

updated using newer exposure assessment models for the proposed new use on apples (DP 

Barcode D415267), this new assessment can be used to support the drinking water exposure 

assessment for registration review. This assessment assumed no use site is intended to have 

maximum single application or yearly rates above 0.375 lbs ai/A. A revised drinking water 

assessment will be needed, however, if the annual application rate assumptions are not confirmed 

by the label clarifications requested for certain uses in the previous section. 

D. Assessment Endpoints 

Assessment endpoints represent the actual environmental value that is to be protected, defined by 

an ecological entity (species, community, or other entity) and its attribute or characteristics 

(USEPA, 1998a). For sulfentrazone, the ecological entities include the following: birds, reptiles, 

terrestrial-phase amphibians, mammals, freshwater fish, freshwater aquatic-phase amphibians 

and invertebrates, estuarine/marine fish and invertebrates, terrestrial plants, insects, aquatic 

plants, and algae. The attributes for each of these entities include growth, reproduction, and 

survival. 

No new sulfentrazone studies have been submitted since the last risk assessment; however, there 

is new information documenting enhanced toxicity of LDPH chemicals to fish in the presence of 

ultraviolet light compared to the toxicity observed under standard laboratory lighting (MRIDs 

46585104 and 46037001). While these studies were not conducted on sulfentrazone, they 

provide data for the interim toxicity adjustment factor recommended by the Environmental Fate 

and Effects Division’s (EFED) Aquatic Biology Technical Team for use in the absence of 

chemical-specific data. Following EFED guidance for LDPH chemicals, an interim 29X toxicity 

adjustment factor was applied to the fish early life stage toxicity data (U.S. EPA, 2010) in order 

to calculate an RQ. 

More information on results of ecotoxicity studies with sulfentrazone is provided in Section III.C

Ecological Effects Characterization of this document. 

Open Literature 

Additional toxicity data were located in the open literature using the ECOTOXicology database. 

A listing of the open literature studies which were considered in this assessment is provided in 

Appendix H: ECOTOX Database Bibliography for Sulfentrazone. 
25 

E. Analysis Plan and Conceptual Models

1. Measures to Evaluate Risk Hypotheses

In the case of sulfentrazone, measures of exposure are based on terrestrial and aquatic exposure 

models that estimate environmental concentrations of sulfentrazone using maximum labeled 

application rates. The T-REX model (version 1.5.2, 6/6/2013) was used to produce terrestrial 

EECs on wildlife food items. The Pesticide Root Zone Model (PRZM) and the Exposure 

Analysis Model System (EXAMS) (see Section III A. 1) are used to produce aquatic EECs. The 

TerrPlant and AgDRIFT models are used to estimate exposure to nontarget plants. For more 

information on EPA’s models, visit http://www.epa.gov/pesticides/science/models_db.htm. 

Measures of effect are obtained from a suite of studies conducted with a limited number of 

surrogate species. The lowest toxicity endpoints for the most sensitive surrogate test species are 

used to estimate treatment-related effects on growth, reproduction and/or survival. 

2. Conceptual Model 

The potential exposure pathways and effects of sulfentrazone are depicted for aquatic 

environments in Figure 2 and for terrestrial environments in Figure 3. Solid lines in each of the 

figures indicate significant routes of exposure; whereas, dashed lines denote exposure routes not 

assessed due to the likelihood of low potential exposure. Likely significant exposure pathways 

to both aquatic and terrestrial organisms include direct application, spray drift, runoff, and 

leaching to groundwater. Non-target plants are expected to be exposed to sulfentrazone from 

direct foliar exposure, from spray drift, and from uptake of sulfentrazone from the roots, and in 

the case of aquatic plants, from absorption from the ambient water. Terrestrial animals are 

expected to be exposed primarily from consumption of contaminated plants and animals that 

were directly sprayed, drinking of contaminated water, and dermal contact to contaminated soil 

and vegetation. Aquatic animals are expected to be exposed primarily from exposure to 

contaminated water. Because of the low potential to accumulate in animal tissue, secondary 

exposure to aquatic and terrestrial animals is expected to be minimal. Because of sulfentrazone’s 

high solubility and low binding potential, exposure to bound residues in soil and sediment is 

expected to be minimal. Finally, due to the low volatility and low Henry’s Law Constant of 

sulfentrazone, exposure from inhalation is not expected to be significant. 
26 

Figure 2. Conceptual model depicting stressors, exposure pathways, and potential effects 

to aquatic animals and plants from the use of Sulfentrazone. 
27 

Figure 3. Conceptual model depicting stressors, exposure pathways, and potential effects 

to terrestrial animals and plants from the use of sulfentrazone. 

3. Risk Hypothesis 
28 

A risk hypothesis describes the predicted relationship among the stressor, exposure, and 

assessment endpoint response along with the rationale for their selection. This risk assessment 

focuses on exposures and potential effects from exposure to sulfentrazone as the sole stressor. 

Currently, there are ongoing efforts between EPA, USFWS, and NMFS, to develop methods to 

assess possible effects of mixture components either quantitatively or qualitatively, if data are 

available on the potential modification of toxicity of the active ingredient(s), or the sensitivity of 

the receptor organism. For sulfentrazone the following ecological risk hypothesis is being 

employed for this national-level ecological risk assessment: 

Sulfentrazone, when used in accordance with current labels, may result in contamination 

of ecosystems and adverse effects upon the survival, growth, and reproduction of nontarget terrestrial and aquatic organisms, including listed species. 

 
29 

III. ANALYSIS 

A. Measures of Exposure 

1. Environmental Fate and Modeling Input Parameters

Physical/Chemical and Environmental Fate Properties 

The physical/chemical properties and environmental fate properties of sulfentrazone along with 

comments on input parameter selection for aquatic exposure modeling are listed in Table 5.

Table 5. Physical/chemical Properties and Environmental Fate Properties of 

Sulfentrazone. 

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 
30 

PARAMETER VALUE(S) SOURCE (Study 

Acceptability 

Classification)a

COMMENTS 

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 (25o C) 

400 @ pH 7.0 

 

Product Chemistry 

Submissions

Vapor Pressure (25o C) 

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 

(25o C) 

6.37x10-13 Calculated Not volatile 

Hydrolysis Half-life @ pH7 

(25o C) 

(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. 

Aqueous Photolysis 

Half-life (25o C) 

pH 5 = 0.50 days 

pH 7 and 9 = 0.05 days 

MRID 43345424, 

43588601 (a) 

Soil Photolysis 

Half-life (25o C) 

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) For aquatic exposure modeling, 

in order to account for reduced 

exposure to sunlight in turbid 

waters, the soil photolysis value 

was used as model input in place 

of the aqueous photolysis halflife. 
31 

PARAMETER VALUE(S) SOURCE (Study 

Acceptability 

Classification)a

COMMENTS 

Aerobic Soil Metabolism 

Half-life (ASM) (T1/2) 

T 1⁄2: 

545 days in sandy loam soil 

538 days in silty clay loam soil 

(25 C) 

The major accumulating 

degradate was 3-carboxylic acid 

sulfentrazone, which reached a 

maximum of 10.8% of the 

recovered residues at the end of 

the course of one study. 

MRIDs 41928203, 

42932117 (a)

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

552.3 days (input for PRZMEXAMS) 

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. 

Anaerobic Aquatic 

Metabolism 

Half-life (days) 

In a water: loamy sand sediment 

system = 3,283 

MRID 43345426 (a) For aquatic exposure modeling 

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 (OCSPP Guideline 

No.835.4300). 

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 PRZMEXAMS is 2x ASM model input 

or 1,105 days. 

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. 
32 

PARAMETER VALUE(S) SOURCE (Study 

Acceptability 

Classification)a

COMMENTS 

Organic Carbon Partition 

Coefficient (Koc) (mL/g) 

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. 

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. 

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

2. Environmental Fate Summary 

Summary 

Sulfentrazone is persistent for months to years and very highly mobile (McCall system, Table 6) 

under most environmental conditions; however, it is subject to rapid photodegradation when 

exposed to sunlight. Overall, sulfentrazone has a strong potential to leach into groundwater and 

move offsite to surface water. This chemical has the following characteristics: (1) water 

solubility sufficient to allow off-site transport (400 ppm); (2) susceptible only slowly 

(extrapolated half-lives 143 - 348 days) to hydrolysis at acidic, neutral, and alkaline pHs; (3) 

subject to rapid photolysis in water; (4) relatively stable to photodegradation on soil; (5) very 

persistent in sandy loam and silty clay-loam soils under aerobic conditions with a half-life of 1.5 

years; (6) essentially stable to anaerobic aquatic metabolism (degradation half-life of several 

years); (7) it is expected to be very mobile in soil (Kads <1; or Koc = 43), (8) non-volatile from 

water and wet/dry soils (vapor pressure <10-9 mmHg; Henry's Law constant = 10-12 atm m3/mol); 

and (9) is not expected to bioaccumulate in fish (Kow = 9.9). 

The major routes of dissipation in the environment appear to be direct aqueous photodegradation, 

runoff, and leaching. Since sulfentrazone is almost stable to hydrolysis and biodegradation, 

rapid loss in the environment likely only occurs from direct photolysis after sulfentrazone is 

transported to clear shallow waters. Low soil/water partition indicates that most sulfentrazone 

runoff is via dissolution in runoff water, as opposed to adsorption to eroding soil. It also 
33 

indicates that most sulfentrazone will be partitioned in the water column instead of in the 

suspended and bottom sediments. Detected environmental degradation products include 3-

carboxylic acid Sulfentrazone (SCA), 3-Hydroxymethyl-sulfentrazone (HMS), 3-Desmethyl 

sulfentrazone (DMS), Methyl triazole (full chemical names and structures are found in Appendix 

D: Chemical Names and Structures); only SCA has been shown to be major. 

Results from each of four field dissipation studies suggested that sulfentrazone was very 

persistent (dissipation half-lives ranged from 4 to 24 months). However, there was no substantial 

downward movement (i.e., leaching) confirmed (detection limit = 1 ppb) at three of the four 

study sites in Illinois (clay loam), Arkansas (silty clay-loam), and in Iowa (silty clay-loam). 

Based on the residues detected in the 0-6 inch soil at the above three study sites, half-lives were 

estimated to be 1-2 years. Results from fourth field dissipation study (a loamy sand in North 

Carolina) suggested much more substantial movement of sulfentrazone, with the compound 

being detected in the deeper soil zones (i.e., 6-12, 12-18, 18-24, 24-30, 30-36, 36-42, 42-48 

inches) as well as in the shallow groundwater. Based on sulfentrazone detected in the entire 48-

inch soil column at the North Carolina site, the dissipation half-life was estimated to be 121 days. 

The relatively short dissipation half-life observed in this site is attributed to leaching. Other 

studies (prospective groundwater monitoring – discussed below) do confirm that significant 

leaching of sulfentrazone occurs in many soils. 

Based on the environmental fate characteristics of sulfentrazone with consideration of the 

application rates and results of the field studies, EFED believes that use of sulfentrazone is likely 

to result in contamination of groundwater and surface water. 

Hydrolysis

Sulfentrazone was relatively stable to hydrolysis with extrapolated half-lives of 143 days at pH 

5, 207-375 days at pH 7, and 348 days at pH 9 in sterile aqueous buffered solutions that were 

incubated at 25o

C in the dark for 30 days. 

Aqueous Photolysis

Sulfentrazone photodegraded with half-lives of 12, 1, and 1 hours in sterile, aqueous pH 5, 7, and 

9 buffer solutions, respectively, that were continuously irradiated at ~25 oC for up to 10 days 

with a uV-filtered xenon arc lamp. The artificial light source had an emission spectrum between 

300 and 800 nm, and the intensity ranged from 522-536 watts/m2

. The intensity of artificial light 

was very close to that of natural sunlight. In contrast, sulfentrazone was relatively stable in the 

dark at all three pH levels for the duration of the exposure period. In the irradiated solutions, 

sulfentrazone was rapidly dechlorinated and hydroxylated into the photodegradates 2,4-

dihydroxy sulfentrazone and des-dichloromonohydroxy sulfentrazone. However, these two 

degradates were short-lived; the chemical bond between the phenyl and the triazole rings was 

subsequently cleaved, resulting methyl triazole, 1,3-dihydroxybenzene, and a methyl triazole 

oxidation product. 

Soil Photolysis 

Sulfentrazone degraded very slowly on sand and sandy loam soils that were irradiated at 14-34 o

C for 12 hours/day for 33 days using a xenon arc lamp. The minor degradate 3-hydroxymethyl 
34 

sulfentrazone (HMS), was identified at 1-3.9% in the irradiated soils. The photolysis on soil halflives were estimated to range from 98 to 161 days. 

Aerobic Soil Metabolism

Uniformly phenyl ring-labeled [14C]sulfentrazone or carbonyl-labeled [5-14C]sulfentrazone 

degraded with half-lives of 535-555 days (approximately 1.5 years) in sandy loam soil and 534-

541 days (approximately 1.5 years) in silty clay loam soil that were incubated in the dark at 25o

C 

and 75% of 0.33 bar moisture. Nonvolatile degradates identified were 3-carboxylic acid 

sulfentrazone, 5'-desmethylsulfonyl sulfentrazone, 3-hydroxymethyl sulfentrazone, and 3-

desmethyl sulfentrazone. The major accumulating degradate was 3-carboxylic acid 

sulfentrazone (SCA) which reached a maximum of 10.8% of the recovered residues at the end of 

the course of the study. The 5'-desmethylsulfonyl sulfentrazone (DMS) degradate reached a 

maximum level of 5.9% of the recovered at 90 days. Less than 2% of the recovered was 

identified as 3-hydroxymethyl sulfentrazone (HMS) or DMS. Material balance ranged from 93-

107%. 

The major metabolic pathway for sulfentrazone in soil under aerobic conditions is the oxidation 

of the methyl group on the triazolinone ring of the parent compound to form HMS. The 

hydroxymethyl group was further oxidized to carboxylic acid, forming SCA. Subsequently, 

SCA was decarboxylated, resulting in DMS. The minor metabolic pathway is the cleavage of 

the sulfonamide group on sulfentrazone, forming 5'-desmethylsulfonyl sulfentrazone. 

Aerobic Aquatic Metabolism

The submitted study (MRID 48958902) is supplemental at this time (possibly upgradeable with 

more data submitted, if available) and therefore the results are not discussed here. Additional 

information is being requested that might allow this study to be upgraded to “acceptable”. 

Anaerobic Soil Metabolism 

The submitted study (MRID 48958901) is classified as supplemental at this time (possibly 

upgradeable with more data submitted, if available) and therefore the results are not discussed 

here. Additional information is being requested that might allow this study to be upgraded to 

“acceptable”.

Anaerobic Aquatic Metabolism

In an acceptable study (MRID 43345426) uniformly phenyl ring-labeled [14C] sulfentrazone or 

carbonyl-labeled [5-14C] sulfentrazone degraded very slowly (<10% degradation) in flooded 

loamy sand sediment (1:5, w:v) that was incubated in the dark under a static nitrogen atmosphere 

at 23-27oC for 12 months. The half-life was estimated to be 3,287 days. One degradate (5'-

desmethylsulfonyl sulfentrazone) was identified in both water and sediment samples. The levels 

of 5'-desmethylsulfonyl sulfentrazone detected in both water and sediment samples were <3% of 

the applied. Material balances ranged from 96.7-102.1% of the applied throughout the study. 

Field Dissipation

Four studies (Culligan, J.F. 1994; MRID 43345427, Culligan, F.F. 1995; MRID 43651009, 

Nagel, W.D. and J.F. Dulligan. 1995; MRID 43651008, and Becker, J.M. 1994; MRID 

43345434) were submitted to satisfy the Field Dissipation data requirement. 
35 

Iowa study - sulfentrazone applied at 0.375 lb ai/A, dissipated with an observed half-life of 

approximately 2 years in the 0-to 6-inch depth of a plot of bare ground silty clay-loam soil in 

Iowa. 

In the 0- to 6-inch soil depth, sulfentrazone averaged 94-206 ppb through 29 days post treatment, 

78-176 ppb at 57 through 365 days, 104-108 ppb at 455 and 531 days. Trace amounts of 

sulfentrazone were detected in the 12-18 inch depth soil at 21, 57, 91, 120, and 180 days. For the 

samples collected at the depth of 30-36 inches, the parent compound was detected only at 180 

days. The degradate SCA, which was converted to DMS to facilitate analysis, was detected in 

all samples collected in the 0-6 inch soil zone (with a range of 4-10 ppb). 

Illinois study - sulfentrazone applied at 0.5 lb ai/A, dissipated with an observed half-life of 

approximately 1 year in the 0- to 6-inch depth of a plot of bare ground clay loam soil in Illinois. 

The degradate SCA, which was converted to DMS to facilitate analysis, averaged <11 ppb in soil 

from the 0- to 6-inch depth and <2 ppb in soil collected from depths below 6 inches at all 

sampling intervals. 

Arkansas study - sulfentrazone applied at 0.375 lb ai/A, dissipated with an observed half-life of 

approximately 1.5 years in the 0- to 6-inch depth of a plot of bare ground silty clay loam soil in 

Arkansas. 

The degradate SCA, which was converted to DMS to facilitate analysis, was detected in all the 0-

6 inch soil samples collected from days 3 to days 554 with a concentration ranging from 3-13 

ppb. 

North Carolina study - sulfentrazone applied at 0.5 lb ai/A, dissipated with an estimated half-life 

of 121 days in the entire 48-inch soil column of a plot of loamy sand soil in North Carolina. 

Sulfentrazone was detected in the soil to a depth of 48 inches, with maximum average 

concentrations of 36.7 ppb in the 6- to 12-inch depth, 10.9 ppb in the 12- to 18-inch depth, 6.6 

ppb in the 18- to 24-inch depth, 5.2 ppb in the 24- to 30-inch depth, 10.8 ppb in the 30- to 36-

inch depth, 3 ppb in the 36- to 42-inch depth, and 1 ppb in the 42-to 48-inch depth. 

The degradate SCA, which was converted to DMS to facilitate analysis, averaged <11.5 ppb in 

soil from the 0- to 6-inch depth and <7.3 ppb in soil collected from depths below 6 inches at all 

sampling intervals. 

 
36 

Mobility

Based on the McCall classification system (Table 6) sulfentrazone (in batch equilibrium studies 

at 0.1, 2, 5, 7, and 10 ppm), was determined to be highly mobile to very highly mobile in sodium 

azide-sterilized sandy loam, silt loam, silty clay loam, and sand soil:calcium chloride solution 

slurries (1:5) (Table 6). Freundlich Kads values were 0.2 for the sand soil, 0.6 for the sandy loam 

soil, 0.8 for the silt loam soil, and 0.8 for the silty clay loam soil; respective Koc values were 77, 

29, 26, and 40. The desorption coefficient (Kdes) values were 1.23-1.44 for the four soils. 

Because their exponent values (1/n) were very close to 1 (1.03 for adsorption; 0.93 for 

desorption=), the adsorption and desorption isotherms were linear. 

Table 6. Mobility classification of pesticides according to the McCall system.

Source: McCall, P. J., Swann, R. L., Laskowski, D. A., Unger, S. M., Vrona, S. A. and Dishburger, H. J. 1980. 

Estimation of chemical mobility in soil from liquid chromatographic retention times, Bull. Environ. Contam. 

Toxicol., 24, 190–195. 

A soil column leaching study provides evidence that the degradation products of sulfentrazone 

are also very highly mobile in soil. Sulfentrazone residues were mobile in columns (12-inch 

length) of sandy loam soil that were treated with aged (30 days) [14C]sulfentrazone residues and 

leached with approximately 20 inches of a 0.01 M calcium chloride solution. Prior to leaching, 

the columns had been topped with sandy loam soil that had been treated with phenyl ring- or 

carbonyl-labeled [14C] sulfentrazone and incubated in the dark at 25 C and 75% of field moisture 

capacity for 30 days. In the soil columns, 25.8-31.3% of the radioactivity applied to the column 

remained in the aged soil layer, 2.5-6.5% was in each 2-inch column segment, and 37.6-44.4% 

was in the column leachates. Two degradates were identified in the soil and leachate: HMS and 

SCA. Both degradation products are very mobile. It appears that HMS is more mobile than 

SCA. Nearly 72% of the applied material was detected as HMS in the leachate at the end of the 

study; whereas, and up to 35% was detected as SCA in the leachate. 

Bioconcentration

Sulfentrazone residues did not accumulate in the edible tissue (muscle) and accumulated only 

slightly in the nonedible tissue (viscera and carcass) of juvenile bluegill sunfish exposed to 

sulfentrazone at 0.94 mg/L for 28 days under flow-through conditions (MRID 43345433). 

Average bioconcentration factors throughout steady state were <1x, 1.8-2.4x, and 1.1-2.0x for 

edible tissue, nonedible tissue, and whole fish, respectively. The degradate, 3-hydroxymethyl 
37 

sulfentrazone, was identified in the viscera. The octanol/water (Kow) partition coefficient of 

sulfentrazone is only 9.9, indicating a low potential for bioaccumulation. 

3. Monitoring Data 

Prospective Small-Scale Groundwater Studies 

The registrant has conducted prospective ground-water monitoring studies at four sites (Table 7, 

Table 8, Table 9, and Table 10). 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. 

Table 7. Description of “95th percentile” ground-water vulnerability site. 

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 8. Description of “85th percentile” ground-water vulnerability site. 

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. 
38 

Table 8. Description of “85th percentile” ground-water vulnerability site. 

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 

Table 9. Description of “75th percentile” ground-water vulnerability site. 

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 10. . Description of “>95th percentile” ground-water vulnerability site. 

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. 
39 

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

(Table 11). The four sites were selected by the registrant to be representative of >95th (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 

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 11. 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 applic. 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 (>95th 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).
40 

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 

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 (NAWQA) – data query at: 

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

No significant occurrence data available for sulfentrazone in groundwater or surface water. 

(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. 

B. Exposure Estimates for Non-target Aquatic Animals and Plants 

 

As noted earlier, the PRZM and EXAMS models are used to derive EECs for aquatic organisms 

from the use of sulfentrazone on registered crops and for the proposed use on apples based on 

various application scenarios. All scenarios were run with at least two different application date 

assumptions: pre-emergence application dates were selected to be one day prior to the plant 

emergence (scenario dependent) and post-emergence date was 40 days after the pre-emergence 
41 

application date. Since some labels did not clearly state whether aerial applications were allowed 

for most uses these were modeled as aerial applications (the labels for the proposed use on apples 

explicitly prohibit aerial application so this use was modeled as a ground application). The 

application rates, reapplication intervals, and date of first application are detailed in Appendix D

(Aquatic Exposure Model Input and Output). In general, preference was given to modeling of a 

single sulfentrazone application at the maximum permitted rate if that equaled the maximum 

annual rate. 

EECs sorted by the estimated acute exposure are presented in Table 12 and Table 13. For use 

sites where application of sulfentrazone might be by aerial or ground equipment, only the aerial 

application simulation results are presented (results for ground applications gave lower EECs). 

Although these EECs are believed to be adequately conservative overall for the ecological risk 

assessment, it was observed in the preparation of this assessment that sulfentrazone exposure 

estimation is particularly sensitive to the degree that sulfentrazone is subject to 

photodegradation. The Florida (FL) peppers scenario with the highest EECs using standard 

model inputs was rerun with the soil photolysis half-life to represent very low exposure of 

sulfentrazone to sunlight that might occur in highly turbid waters. The rationale for this was 

based on the fact that the sunlight exposure opportunity may be much less than assumed with the 

standard EXAMS model simulation. Results are presented in Table 12 and Table 13. Using a 

longer photolysis half-life has a significant effect (increases) the EECs because, whenever a 

sulfentrazone molecule is exposed to sunlight, it will degrade much more rapidly than it will by 

any other transformation pathway. 

Table 12. Tier 2 Surface Water Estimated Environmental Concentrations (EECs) for 

Registered Uses of Sulfentrazone.

Scenario 

State 

Scenario 

Crop4

Repres. Crop 

for 

Sulfentrazone 

App. Date 

in Days 

before 

/after 

Emergn.

EEC 

μg/L (sorted by acute EECs) 

Peak 4-Day 21 Day 60 Day

FL Pep Peppers 40 17.94 17.56 15.95 13.08 

FL Sgc Sugarcane 40 16.89 16.50 14.97 12.38 

LA Sgc Sugarcane 40 15.68 15.38 14.30 12.26 

MS Cor Corn -1 14.44 14.15 12.97 10.69 

LA Sgc Sugarcane -1 13.52 13.23 12.71 10.75 

FL Sgc Sugarcane -1 13.22 11.44 10.37 8.59 

FL Pep Peppers -1 10.57 10.28 9.49 7.80 

FL Cuc Peppers -1 9.27 9.06 8.34 6.81 

 

4

 See Appendix E for full crop names for each scenario. 
42 

Scenario 

State 

Scenario 

Crop4

Repres. Crop 

for 

Sulfentrazone 

App. Date 

in Days 

before 

/after 

Emergn.

EEC 

μg/L (sorted by acute EECs) 

Peak 4-Day 21 Day 60 Day

FL Str Strawberries 40 8.10 7.90 7.13 4.53 

FL Cuc Peppers 40 7.51 7.37 6.71 3.73 

PA Tma Tomatoes 40 7.12 6.98 6.45 5.41 

FL Cit Citrus 40 7.00 6.84 6.30 5.16 

ME Pot Potatoes 40 6.79 6.67 6.35 5.48 

FL Str Strawberries -1 6.77 6.60 5.98 4.80 

FL Cit Citrus -1 7.63 6.44 5.85 4.78 

FL Tma Tomatoes 40 6.43 6.28 5.77 4.71 

MS Cor Corn 40 6.07 5.94 5.58 4.57 

PA App Apples 40 5.61 5.51 5.09 4.26 

KS2 Srg Sugarcane 40 5.19 5.08 4.68 3.83 

NC App Apples 40 5.15 5.05 4.65 3.82 

FL Cbb Cabbage, 

Brassica -1 5.05 4.93 4.46 3.60 

IL Cor Corn -1 4.87 4.78 4.46 3.70 

PA Cor Corn 40 4.84 4.75 4.39 3.69 

MS Syb Soybeans 40 4.65 4.59 4.20 3.42 

GA Pcn Tree Nuts 40 4.51 4.41 4.01 3.27 

MI Bea Dry, lima 

beans -1 4.45 4.37 4.10 3.56 

ND Cno Sunflower 40 4.44 4.36 4.03 3.36 

MS Syb Soybeans -1 4.44 4.33 3.99 3.29 

MI Bea Dry, lima 

beans 40 4.32 4.23 4.01 3.39 

OH Cor Corn -1 4.24 4.17 3.91 3.29 

GA Pcn Tree Nuts -1 4.22 4.12 3.75 3.03 
43 

Scenario 

State 

Scenario 

Crop4

Repres. Crop 

for 

Sulfentrazone 

App. Date 

in Days 

before 

/after 

Emergn.

EEC 

μg/L (sorted by acute EECs) 

Peak 4-Day 21 Day 60 Day

NC Cor Corn -1 4.15 4.06 3.71 3.06 

FL Cbb Cabbage, 

Brassica 40 4.11 4.02 3.67 2.52 

IL Cor Corn 40 3.98 3.90 3.56 2.98 

PA Tma Tomatoes -1 3.94 3.88 3.60 2.99 

ME Pot Potatoes -1 3.69 3.63 3.44 2.98 

CA Tma Tomatoes -1 3.28 3.20 2.88 2.33 

NY2 Gra Grapes, Berries 40 3.25 3.20 3.02 2.68 

NC Pnt Peanuts -1 3.20 3.16 2.92 2.62 

OH Cor Corn 40 3.16 3.13 2.90 2.43 

NC Cor Corn 40 3.10 3.03 2.78 2.30 

FL Tma Tomatoes -1 3.07 3.00 2.74 2.28 

ND Whe Wheat 40 3.02 2.96 2.77 2.35 

CA Cit Citrus 40 2.90 2.84 2.60 2.17 

CA Wal Tree Nuts -1 2.78 2.74 2.52 2.13 

KS2 Srg Sugarcane -1 2.71 2.67 2.44 2.01 

NC Tba Tobacco -1 2.69 2.64 2.41 2.00 

NY2 Gra Grapes, Berries -1 2.59 2.54 2.39 2.00 

NC Pnt Peanuts 40 2.54 2.51 2.33 2.15 

OR Xma Fallow 40 2.54 2.50 2.36 2.03 

PA Cor Corn -1 2.47 2.43 2.27 1.92 

CA Tma Tomatoes 40 2.36 2.31 2.11 1.77 

OR Gra Grapes, Berries 40 2.32 2.28 2.13 1.85 

ND Cno Sunflower -1 2.18 2.14 2.00 1.70 

OR Fil Tree Nuts -1 2.15 2.11 1.96 1.68 
44 

Scenario 

State 

Scenario 

Crop4

Repres. Crop 

for 

Sulfentrazone 

App. Date 

in Days 

before 

/after 

Emergn.

EEC 

μg/L (sorted by acute EECs) 

Peak 4-Day 21 Day 60 Day

NC Tba Tobacco 40 2.14 2.10 1.92 1.60 

FL Tur Turf, sod 40 2.03 1.99 1.82 1.46 

OR Gra Grapes, Berries -1 2.02 1.98 1.83 1.58 

ND Whe Wheat -1 1.91 1.89 1.80 1.57 

PA App Apples -1 1.86 1.83 1.69 1.43 

NC App Apples -1 1.87 1.83 1.68 1.39 

CA Wal Tree Nuts 40 1.77 1.74 1.60 1.32 

OR Fil Tree Nuts 40 1.76 1.73 1.61 1.37 

CA Gra Grapes, Berries -1 1.74 1.70 1.57 1.32 

CA Gra Grapes, Berries 40 1.71 1.68 1.58 1.30 

OR Xma Fallow -1 1.68 1.65 1.55 1.36 

PA Tur Turf, sod 40 1.64 1.61 1.48 1.25 

OR Min Mint -1 1.39 1.36 1.26 1.07 

FL Tur Turf, sod -1 1.38 1.35 1.23 1.02 

OR App Apples -1 1.19 1.18 1.11 0.97 

OR Min Mint 40 1.18 1.16 1.07 0.99 

OR App Apples 40 1.17 1.16 1.07 0.89 

PA Tur Turf, sod -1 1.17 1.15 1.07 0.94 

MI Asp Asparagus -1 1.16 1.14 1.05 0.87 

MI Asp Asparagus 40 1.16 1.14 1.04 0.90 

CA Cit Citrus -1 1.13 1.11 1.04 0.87 

ID Pot Potatoes -1 0.92 0.90 0.83 0.71 

ID Pot Potatoes 40 0.92 0.90 0.83 0.71 

Bolded crops represent those with the highest use rates (in lbs a.i.) in Table 3. 
45 

Table 13. Tier 2.5 Surface EECs for Sulfentrazone: Effect of Different Assumptions of 

Light Availability in Farm Pond for a High Exposure Use. 

Scenario 

State 

Scenario 

Crop App. Date Photoly. Input 2

EEC 

μg/L 

Peak 4-Day 21 Day 60 Day 

FL 1 Peppers 11-Oct 98 28.44 28.27 27.74 26.30 

FL Peppers 31-Oct 98 27.67 27.51 26.88 25.39 

FL Peppers 31-Oct 0.5 21.30 20.85 19.09 15.39 

FL Peppers 11-Oct 0.5 17.97 17.55 15.96 13.11 

FL Peppers 20-Sep 98 16.79 16.71 16.37 15.64 

FL Peppers 31-Aug 98 14.46 14.37 14.00 13.25 

FL Peppers 20-Sep 0.5 12.95 12.69 11.56 9.42 

FL Peppers 31-Aug 0.5 10.55 10.31 9.49 7.79 

1 Bold lines indicate EECs used to calculate aquatic RQs. 

2 In this run, photolysis input of 98 days was used instead of the 0.5 days used in modeling EECs, above (in Table 13 to 

presume exposure to sulfentrazone in turbid waters 

Risk to fish and aquatic invertebrates was assessed using the conservative assumption of a single 

application at the maximum annual application rate (0.375 lb a.i./A), applied as an aerial spray. 

EECs were calculated using fast photolysis rates (0.5) when waters were exposed to light since 

sulfentrazone is an LDPH, which may change its toxicity depending on timing and exposure to 

light. 

Terrestrial Modeling and Input Parameters. Terrestrial exposure estimates for avian and 

mammalian risk assessments were derived using the T-REX model (version 1.5.2, 6/6/2013). To 

provide a conservative screen of risk to terrestrial animals, all runs of T-REX were done for a 

single application at the maximum annual rate of 0.375lb a.i./A, the highest application rate 

permitted for any use of sulfentrazone. Spray applications with ground equipment were 

assumed. 

Because data were not available to estimate the foliar dissipation rate of sulfentrazone on plants, 

and because environmental fate data indicate that sulfentrazone is persistent in the environment, 

the default value of 35 days was used as the foliar half-life. As only one application was 

modeled, the peak EEC which is used to calculate acute and chronic risk quotients occurs 

immediately after application. Therefore, the selection of the foliar half-life has no effect on the 

calculated terrestrial EECs or RQs. 
46 

The TerrPlant (v. 1.2.2; December 26, 2006) model is used to derive EECs relevant to terrestrial 

and wetland plants for the proposed new uses of sulfentrazone. The model employs the assumption 

that default fractions of the intended application are transported to an adjacent field through runoff 

and spray drift. Measures of exposure to terrestrial plants are expressed as a fraction of the mass 

of the sulfentrazone applied to the treated field. 

Input parameters for the T-REX model are presented in Table 14 through Table 16. 

Table 14. Input Parameters for T-REX Modeling for All Uses of Sulfentrazone

Input Parameters Value Source 

Single Application Rate All 

(lb a.i./A) Uses: 0.375 Product labels 

Foliar Half-life 35 days Default value1

Number of Applications 

(Interval between 

Applications, days) 

All 

Uses: 1 Product labels 

Avian Oral LD50 2,250 mg/kg-bw (bobwhite) MRID 41911617 

Avian Repro NOEAC 10 ppm (bobwhite) MRID43355901 

Mammal LD50 2855 mg/kg-bw (rat) MRID 41911605 

Mammal NOAEC 200 mg/kg-diet (rat) MRID 4334508 

1 The foliar half-life did not influence the prediction of the terrestrial EECs for sulfentrazone because only 

one application of sulfentrazone is allowed per season, and thus the peak concentration occurs immediately 

after this single application before any dissipation occurs. 

Terrestrial EECs for dietary-based calculations are given in Table 15, and terrestrial EECs for 

dose-based calculations are given in Table 16. These EECs are based on all uses with a single 

application of sulfentrazone at the maximum rate of 0.375 lb a.i./A. Complete output from TRex Model is provided in Appendix F: Terrestrial Exposure Model Results. 

Table 15. Dietary-Based Sulfentrazone EEC Values for 0.375 lb a.i. lb /A application rate.

Dietary-based EECs (ppm) Kenaga 

Values 

Short Grass 90.00 

Tall Grass 41.25 

Broadleaf plants 50.63 

Fruits/pods/seeds 5.63 

Arthropods 35.25 

Table 16. Avian and Mammalian Dose-Based Sulfentrazone Upper-Bound EEC Values
47 

Dose-based EECs 

(mg/kg-bw) 

Avian Classes and Body Weights (grams) 

small mid large 

20 100 1000 

Short Grass 102.50 58.45 26.17 

Tall Grass 46.98 26.79 11.99 

Broadleaf plants 57.66 32.88 14.72 

Fruits/pods 6.41 3.65 1.64 

Arthropods 40.15 22.89 10.25 

Seeds 1.42 0.81 0.36 

Dose-Based EECs 

(mg/kg-bw) 

Mammalian Classes and Body weight 

(grams) 

15 35 1000 

Short Grass 85.81 59.30 13.75 

Tall Grass 39.33 27.18 6.30 

Broadleaf plants 48.27 33.36 7.73 

Fruits/pods 5.36 3.71 0.86 

Arthropods 33.61 23.23 5.39 

Seeds 1.19 0.82 0.19 

C. Ecological Effects Characterization 

The ecological effects characterization for sulfentrazone is based upon registrant-submitted 

toxicity data for the technical grade active ingredient (TGAI). Endpoints derived from literature 

returned from the ECOTOX search were not determined to be useful for this risk assessment due 

to improper study design or endpoints that were derived that were less sensitive that the 

submitted data to the EPA. The ecotoxicity data for sulfentrazone have been reviewed 

previously in the Preliminary Problem Formulation for Registration Review (USEPA 2009). 

These data are summarized briefly below. 

1. Aquatic Animals 

There are two acute freshwater fish toxicity studies available for sulfentrazone (Table 17). In a 

flow-through study with the rainbow trout (Oncorhynchus mykiss, MRID 41911620), the 96-

hour LC50 was determined to be >120 mg a.i/L. This study is classified as acceptable. In a 

second flow-through study conducted with the bluegill sunfish (MRID 41911621), the 96-hour 

LC50 was determined to be 93.8 mg a.i/L. This study is classified as acceptable. Based on these 

data sulfentrazone is classified as slightly toxic to freshwater fish on an acute exposure basis. 

Since freshwater fish serve as a surrogate for aquatic-phase amphibians, sulfentrazone is 

considered slightly toxic on an acute exposure basis to these taxa as well. 

There is one acute toxicity test available for the freshwater invertebrate Daphnia magna (Table 

17). In a static study (MRID 41911622), the 48-hr EC50 was determined to be 60.4 mg a.i/L. 

This study was classified as core. Based on the results of this study, sulfentrazone is classified as 

slightly toxic to freshwater invertebrates on an acute exposure basis. 
48 

An acute toxicity study with the estuarine/marine silverside (Menidia beryllina, MRID 

43588602) was submitted in support of sulfentrazone (Table 17). There were not any sublethal 

effects observed during testing. The 96-hr LC50 for this study was determined to be 114 mg a.i/L 

and this study is classified as acceptable. The results of this study indicate that sulfentrazone is 

practically non-toxic to estuarine/marine fish on an acute exposure basis. 

Two acute estuarine/marine invertebrate studies have been submitted in support of sulfentrazone 

(Table 17). In a 96-hour shell deposition study with the Eastern oyster (Crassostrea virginica, 

MRID 44054901) the EC50 was determined to be >10.5 mg a.i/L. This study is classified as 

supplemental because a non-definitive endpoint was reached and concentrations were not tested 

up to the limit dose (100 mg a.i./L). 

In another study conducted with the saltwater mysid (Americamysis bahia, MRID 43588603), 

the LC50 was determined to be 1.0 mg a.i/L. Sublethal effects included lethargy at 1.2 mg a.i./L; 

this study is classified as acceptable. Based on these data, sulfentrazone is classified as highly 

toxic to estuarine/marine invertebrates on an acute exposure basis. 

There are no sediment toxicity studies available for sulfentrazone; however, the soil partition 

constant (Kd) is low and the compound is not expected to bind to sediment. Therefore, sediment 

toxicity studies are not triggered for this compound according to the CFR 40 part 158.630 

subpart G. 

Table 17. Acute Toxicity of Sulfentrazone to Aquatic Animals. (Bolded values represent 

most sensitive value used for estimating RQs.)

Species Study 

Type 

Test 

Substance 

(Purity) 

LC50

(mg a.i/L)1,2,3

(95% CL; 

slope) 

Toxicity 

Classification 

(MRID) 

Rainbow trout Oncorhynchus mykiss

96-hour, 

flowthrough 

TGAI 

(94.3%) > 120 (N/A) Practically non-toxic 

(419116-20) 

Bluegill sunfish (Lepomis 

macrochirus) 

96-hr, 

flowthrough 

TGAI 

(94.3%) 93.8 (N/A) Slightly toxic (419116-21) 

Water flea 

48-hr, 

static 

TGAI 

(94.3%) 60.4 (N/A) Slightly toxic (41911622) (Daphnia magna) 

Silverside 

(Menidia beryllina)

96-hour, 

flowthrough 

TGAI 

(94.2%) 

114 Practically non-toxic 

(43588602) (67 – >114; 

N/A) 
49 

Eastern oyster 

Crassostrea virginica

96-hour, 

flowthrough 

TGAI 

(92.5%) >10.5 Slightly toxic (44054901) 

Saltwater mysid 

Americamysis bahia

96-hour, 

flowthrough 

TGAI 

(94.2%) 

1 

(0.8-1.2;N/A)

Highly toxic 

(43588603) 

One chronic toxicity study conducted on freshwater fish is available for sulfentrazone (Table 

18). In an early life stage study with the rainbow trout (MRID 43588604), statistically 

significant effects were observed in survival sixty days post hatch and mean length of surviving 

individuals. There was a 37 % decrease at the LOAEC treatment concentration of 5.93 mg a.i./L 

relative to the control. Additional sub-lethal effects such as lethargy were observed. The 

NOAEC and LOAEC for this study were determined to be 2.95 and 5.93 mg a.i./L, respectively, 

based on reductions in larval survival and fish length. This study is classified as acceptable. 

Since the submission of this study, EFED has received new information documenting enhanced 

toxicity of LDPHs to fish in the presence of ultraviolet light compared to the toxicity observed 

under standard laboratory lighting (MRIDs 46585104 and 46037001). While these studies were 

not conducted on sulfentrazone, they provide data for the interim toxicity adjustment factor 

recommended by the EFED Aquatic Biology Technical Team (U.S. EPA, 2010) for use in the 

absence of chemical specific data. Following EFED guidance for LDPH chemicals, an interim 

29X toxicity adjustment factor was applied to the fish early life stage study. This factor results 

in an adjusted NOAEC of 0.2 mg a.i. /L which is used in calculation of the risk quotients.

In a chronic life cycle study conducted with D. magna under a flow-through system (MRID 

43588605; Table 18), sub-lethal signs of toxicity included pale coloration, small appearance, and 

lethargy at the 0.85 and 1.7 mg a.i./L. The NOAEC and LOAEC for this study were determined 

to be 0.2 and 0.51 mg a.i/L based on the number of dead/immobile adult daphnids. This study is 

classified as acceptable. 

There is no chronic test for estuarine fish because the chemical characteristics and toxicity of 

sulfentrazone do not suggest that exposures will significantly impact estuarine fish since the ratio 

of the EC50 to the EEC is <0.01. There is also no chronic life cycle toxicity test for 

estuarine/marine invertebrates. By using the acute-to-chronic ratio (ACR) for daphnids (i.e., 

acute EC50=60.4 divided by the chronic NOAEC=0.2 yields an ACR= 302) and applying that 

ACR to the mysid (i.e., LC50=1 divided by the ACR=302), the NOAEC for the mysid shrimp is 

estimated to be 0.003 mg a.i. /L. 

Table 18. Chronic Toxicity of Sulfentrazone to Aquatic Animals
50 

Species Study Type 

Test 

Substance 

(Purity) 

NOAEC; 

LOAEC 

(mg a.i/L) 1,2

Endpoints 

(MRID) 

Rainbow 

Trout 

Oncorhynchus 

mykiss

99-d Early Life 

Stage 

TGAI 

(94.2%) 2.95; 5.93 

Number of survivors; fish length 

-43588604 

Water flea 

21-day Life 

Cycle 

TGAI 

(94.2%) 0.2; 0.51 Survival (43588605) (Daphnia 

magna) 

Saltwater 

mysid      

0.003

NOAEC derived from the Daphnid 

acute-to-chronic ratio (60.4/0.2 = 

302) and the mysid acute value3 Americamysis 

bahia      

1

Bolded values represent the most sensitive toxicity endpoints for freshwater invertebrates exposed to parent 

sulfentrazone and therefore will be used in risk estimation. 

2

Based on mean measured concentrations 

3

 The acute to chronic ratio (ACR) uses the ratio between the acute and chronic daphnid endpoints to derive the chronic 

end point for the saltwater mysid. The mysid is 60 times more sensitive than the daphnid based on acute toxicity. 

2. Aquatic Plants 

Four nonvascular aquatic plant toxicity tests and one vascular aquatic plant test are available for 

sulfentrazone ( Table 19). The first nonvascular plant study, conducted with the freshwater 

green algae, Pseudokirchneriella subcapitata (formerly Selenastrum capricornutum; MRID 

43345413), resulted in a 96-hr EC50 of 0.031 mg a.i/L and a NOAEC of 0.016 mg a.i/L based on 

reduced cell density. This study is classified as acceptable. The second study, conducted with 

the cyanobacteria Anabaena flos-aquae (MRID 43651006), resulted in an EC50 of 32.8 mg a.i/L 

based on reduced cell density. The NOAEC was non-definitive, i.e., <15.9 mg a.i/L. As a result 

of the non-definitive determination this study is classified as supplemental but is still useful for 

risk assessment purposes. The third study, conducted with the marine diatom Skeletonema 

costatum (MRID 43651007), resulted in a NOAEC and EC50 of 0.075 and 0.042 mg a.i/L, 

respectively, based on reduced cell density. This study is classified as acceptable. The fourth 

study, conducted with the freshwater diatom Navicula pelliculosa, resulted in a NOEAC and 
51 

EC50 of 0.075 and 0.042 mg a.i/L, respectively, both based on reduced cell density. This study is 

classified as acceptable. 

The vascular aquatic plant study conducted with duckweed Lemna gibba resulted in a NOAEC 

and EC50 of 0.018 and 0.0288 mg a.i/L, respectively, both based on reduced frond count. This 

study is classified as acceptable. 

 Table 19. Acute Toxicity Values of Sulfentrazone to Aquatic Plants 

Species Study 

Type 

Test Substance 

(Purity) 

NOAEL; EC50

Effect (MRID) (mg a.i./L) 

(95% CL)1,2

Formerly Selenastrum 

capricornutum Printz 

(Pseudokirchneriella 

subcapitata) 

120-hr, 

static TGAI (94.2%) 

0.016 ; 0.031 

Cell density (43345413) (0.03-0.033) 

Anabaena flos-aquae 120-hr, 

static TGAI (94.2%) <15.9 ; 32.8 Cell density (43651006) (29.0-36.6) 

Skeletonema costatum 120-hr, 

static TGAI (94.2%) 1.35 ; 1.8 Cell density (43651007) (1.72-2.0) 

Navicula pelliculosa 120-hr, 

static TGAI (94.2%) 

0.075; 0.042 

Cell density (43651004) (0.038-0.0463) 

Lemna gibba 14-Day, 

static TGAI (94.2%) 

0.019; 0.0288 

Frond Count (43651005) (.0189-0.0375) 

N/A = Not available. 

1

Bolded values represent the most sensitive toxicity endpoints for nonvascular aquatic plants exposed to parent 

sulfentrazone and therefore will be used for risk estimation. 

2

Based on mean measured concentrations. 

3. Terrestrial Animals 

Table 20 presents the acute toxicity data used to assess the risk of sulfentrazone to terrestrial 

animals. The available data indicate that sulfentrazone TGAI is practically non-toxic to birds on 

an acute oral basis, it is practically non-toxic to birds on a subacute dietary exposure basis, and it 

is practically non-toxic to mammals on an acute oral exposure basis. Sulfentrazone is also 

practically non-toxic to young adult honey bees (Apis mellifera) on both an acute contact and 

oral exposure basis. Since birds serve as surrogates for terrestrial-phase amphibians and reptiles, 

sulfentrazone is considered practically non-toxic on an acute exposure basis to these taxa as well

There was one acceptable acute oral study and two subacute dietary toxicity studies submitted in 

support of sulfentrazone. The acute oral toxicity study was conducted with the bobwhite quail 

(Colinus virginianus; MRID 41911617) and the LD50 was determined to be >2250 mg a.i/kg bw. 

Based on these data, sulfentrazone is classified as practically non-toxic to birds on an acute oral 

exposure basis. 
52 

The 8-day subacute dietary study with the bobwhite quail (MRID 41911618) and with mallard 

ducks (Anas platyrhynchos, MRID 41911619) both resulted in an LD50 of >5620 mg a.i/kg bw. 

Based on these data, sulfentrazone is classified as practically non-toxic to birds on a subacute 

dietary exposure basis. 

In an acute oral toxicity study with the laboratory rat (Rattus norvegicus, MRID 41911605), the 

LD50 was determined to be 2855 mg a.i/kg bw (for both males and females). This study is 

classified as acceptable and indicates that sulfentrazone is practically non-toxic to mammals on 

an acute oral exposure basis. 

Two studies that included both acute contact and acute oral exposure on the honey bee were 

submitted in support of sulfentrazone (MRID 43678166, 44054902, Table 20). Other than a 

single mortality at the 50 μg a.i/bee treatment and there were no other adverse effects observed. 

In the acute oral exposure portion of the experiment, there were four mortalities during this study 

though none appeared to be related to the dose. The 48-hr acute contact LD50 with TGAI was 

>200 μg a.i/bee for acute contact and >25 μg a.i/bee for acute oral exposure. Based on these 

data, sulfentrazone is classified as practically non-toxic to honey bees on both an acute oral and 

contact exposure basis. The studies are classified as acceptable. In a second study, a limit acute 

contact exposure (MRID 44054902) reported that the 48-hr LD50 was >25.1 μg a.i/bee. This 

study is classified as acceptable and classifies sulfentrazone as practically non-toxic to honey 

bees. 

Table 20. Acute Toxicity of sulfentrazone to Terrestrial Species 

Species Study 

Type 

Test 

Substance 

(Purity) 

LD50

(mg/kg bw) 

or 

LC50

(mg/kg 

diet); (95% 

CI; slope)1,2

Toxicity Classification (MRID) 

Bobwhite quail Acute 

oral 

toxicity 

TGAI 

(94.3%) 

>2250 

mg/kg; N/A; 

N/A 

Practically nontoxic 

(Colinus 

virginianus) (41911617)

Bobwhite quail Subacute 

dietary 

toxicity 

TGAI 

(94.3%) 

>5620 ppm; 

N/A; N/A 

Practically nontoxic 

(Colinus 

virginianus) (41911618)

Mallard duck TGAI 

(94.3%) 

>5620 ppm; 

N/A; N/A Practically nontoxic 
53 

(Anas 

platyrhynchos) 

Subacute 

dietary 

toxicity 

(41911619)

Norway rat (Rattus 

norvegicus) 

Acute 

oral 

toxicity 

14-d LD50 = 

2855 mg 

a.i/kg bw 

Practically non-toxic 

(41911605) 

Norway rat (Rattus 

norvegicus) 

Acute 

dermal 

toxicity 

>2000 mg 

a.i/kg bw 

Practically non-toxic 

(41911607,42286400) 

Honey bee (Apis 

mellifera) 

Acute 

contact 

toxicity 

(TGAI 

96.2 %) 

>200 μg 

a.i./bee 

Practically non-toxic 

(43678166)

Honey bee (Apis

mellifera)

Acute 

oral 

toxicity 

(TGAI 

94.2 %) 

>25.1μg 

a.i./bee 

Practically non-toxic 

(44054902, 43678166)

Table 21 provides results of chronic toxicity tests conducted with birds and mammals. There are 

two acceptable avian reproduction studies submitted in support of sulfentrazone. In one study 

conducted with the bobwhite quail (MRID 43355901), the NOAEC and LOAEC were 

determined to be 10 ppm and 100 ppm, respectively, based on reductions in 14-day old survivor 

weight with an 8% reduction at the LOAEC relative to the control. No reproductive parameters 

were adversely affected at any test concentration. The bobwhite quail study is classified as 

acceptable given application rates of 0.375 lb a.i./A and only one application per year/season. 

The NOAEC and LOAEC were determined to be 100 ppm and >100 ppm, respectively, based on 

the avian reproduction study conducted with the mallard duck (MRID 443355902). In this study 

there were none of the measurement endpoints were adversely affected. This study is classified 

as supplemental since the study did not establish a LOAEC. 

In a 2-generation reproduction study with the laboratory rat (MRIDs 43345408) dietary exposure 

to sulfentrazone resulted in decreased maternal body weight and/or body weight gain during 

gestation in both generations (P and F1) and reduced pre-mating body weight gains in the F1

males. For both generations, the following effects were also noted: increased duration of 

gestation, reduced prenatal viability (fetal and litter), reduced litter size, increased number of 

stillborn pups, reduced pup and litter postnatal survival, and decreased pup body weights 

throughout lactation. Male fertility was reduced in the F1 generation at 500 and 700 mg/kg diet 

(ppm). Histopathological evaluation of the reproductive organs of the F1 males revealed 

degeneration and/or atrophy of the germinal epithelium of the testes and oligospermia and 

intratubular degenerated seminal product in the epididymides. 
54 

The NOAEL for reproductive toxicity is 200 ppm (14 mg/kg/day for males; 16 mg/kg/day for 

females) and the LOAEL is 500 ppm (33 mg/kg/day for males; 40 mg/kg/day for females), based 

upon reduced pre-mating body weight gain in F1 males, decreased F1 male fertility, increased 

gestation duration, reduced litter size, pre- and postnatal pup and litter survival, and pup weight 

throughout lactation in both generations of offspring. This study was classified as acceptable.

Table 21. Chronic Toxicity of Sulfentrazone to Terrestrial Animals 

Species Study Type 

Test 

Substance 

(Purity) 

NOAEC; LOAEC 

(mg/kg diet)

Endpoints 

MRID 

Northern bobwhite 

quail 

Colinus virginianus

Chronic 

reproduction 

(94.2%) 

TGAI 10 ppm a.i.; 100 ppm a.i. 

Female body weight 

gain 

43355901 

Mallard duck 

(Anas platyrhynchos) 

Chronic 

reproduction 

(94.2%) 

TGAI 100 ppm a.i.; >100 ppm a.i. None affected 

43355902 

Norway rat (Rattus 

norvegicus) 

Two 

generation 

reproductive 

toxicity 

NS1 NOAEC= 200 ppm 

LOAEL = 400 ppm 

Reproduction and 

Growth 

43345408 

1

NS: Not specified 

4. Terrestrial Plants 

Results of Tier II terrestrial plant toxicity tests with sulfentrazone are summarized in Table 22. 

In a Tier 2 vegetative vigor study (MRID 43345412) with sulfentrazone technical (94.2%), all 

crops exhibited significant effects, mainly foliar desiccation and burning, ten days after 

treatment. The onion was the monocot with the lowest EC25 and NOAEC of 0.012 and 0.006 lb 

ai /A, respectively, based on decreased dry weight. The cucumber was the dicot with the lowest 

EC25 and NOAEC of 0.00052 and 0.00044 lb ai /A, respectively, based on decreased dry weight. 

In a Tier 2 seedling emergence study (MRID 43345411) with sulfentrazone technical (94.2%), 

the treatment doses were nominal concentrations of 0, 0.006, 0.019, 0.056, 0.167, 0.5 lb ai / acre. 

Ten days after treatment, all crops exhibited significant effects, mainly foliar desiccation and 

burning, ten days after treatment. The oat was the monocot with the lowest EC25 and NOAEC of 

0.023 and 0.019 lb ai /A, respectively, based on decreased dry weight. Lettuce was the most 

sensitive dicot with an EC25 and NOAEC of 0.01 and 0.006 lb ai /A, respectively, based on 

decreased dry weight. 
55 

Table 22. Toxicity of Sulfentrazone to Terrestrial Plants. (Bolded values are the most 

sensitive endpoints used for assessing risk to terrestrial plants.) 

Crop 

Type of 

Study 

Species 

EC25 NOAEL

or EC05

(lbs 

a.i./A) 

Endpoint 

Affected MRID (lbs 

a.i./A) 

  

Vegetative Vigor (Sulfentrazone 94.2% TGAI) 

Monocots 

Corn 0.18 0.056 Dry weight

43345412 

Oat 0.033 0.006 Dry weight

Onion 0.012 0.006 Dry 

weight 

Ryegrass 0.045 0.019 Dry weight

Dicots 

Cabbage 0.011 0.006 Dry weight

Lettuce 0.025 0.006 Dry weight

Tomato 0.012 0.0013 Dry weight

Radish 0.057 0.019 Dry weight

Soybean 0.0044 0.0013 Dry weight

Cucumber 0.00052 0.00044 Dry 

weight 

Seedling Emergence (Sulfentrazone 94.2% TGAI) 

Monocots 

Corn 0.051 0.167 Dry weight

43345411 

Oat 0.023 0.019 Dry 

weight 

Onion 0.028 0.019 Plant 

height 

Ryegrass 0.048 0.019 Dry weight

Dicots 

Cabbage 0.047 0.056 Dry weight

Lettuce 0.011 0.006 Dry 

weight 

Tomato 0.013 0.006 Dry weight

Radish 0.039 0.019 Dry weight

Soybean 0.3 0.056 Dry weight

Cucumber 0.036 0.019 Dry weight

N/D = not determined, N/A = not applicable 

IV. RISK ESTIMATION 

This screening-level assessment of the labeled uses of sulfentrazone relies on the deterministic RQ 

method to provide a metric of potential risks. The RQ provides a comparison of exposure estimates 

to toxicity endpoints (i.e., the estimated exposure concentrations are divided by acute and chronic 

toxicity values, respectively). The resulting RQ values do not have units and are compared to the 
56 

Agency’s LOCs. The LOCs are used by the Agency to indicate when the use of a pesticide, as 

directed by the label, has the potential to cause adverse effects to non-target organisms. For listed 

species, when RQs exceed the LOCs, there is an additional in-depth listed species evaluation of 

the potential co-occurrence of listed species and areas in which new use crops are grown to 

characterize risks. In this assessment, RQs that exceed the non-listed species LOC also exceed the 

listed species LOC. 

All acute RQs (Table 23) for aquatic animals were below the LOCs for both listed species 

(LOC=0.05) and for non-listed species (LOC=0.5). Chronic toxicity data were available for 

freshwater fish and a freshwater invertebrate, but not for saltwater species. RQs for freshwater 

species were below the chronic risk LOC of 1 for listed and non-listed aquatic species. In the 

absence of chronic toxicity data for the estuarine invertebrate species, the NOAEC for the 

saltwater mysid shrimp was derived using the acute to chronic ratio (ACR of D. magna. By 

using the ACR, the NOAEC for the mysid shrimp is estimated to be 0.003 mg a.i./L. This results 

in a RQ of 5.3 in clear waters and exceeds the chronic risk LOC for both non-listed and listed 

species. 

Since sulfentrazone is an LDPH chemical an adjustment factor of 29 was applied to the chronic 

fish test by dividing the chronic fish toxicity endpoint by 29 prior to calculating the RQ. The 

subsequent RQs that incorporated this uncertainty factor remained below the chronic risk LOC 

for both listed and non-listed species. 

Based on the screening-level assessment the likelihood that the existing uses or the proposed use 

on of sulfentrazone on apples will result in adverse effects to fish and freshwater aquatic 

invertebrates from either acute or chronic exposure is considered low. Estuarine/marine 

crustaceans, however, appear to be 60 times more sensitive to sulfentrazone than freshwater 

invertebrates. This sensitivity is not however observed in the study with estuarine/marine 

mollusks demonstrating variable responses among taxa. The enhanced sensitivity of 

estuarine/marine crustaceans results in the conclusion that the use of sulfentrazone may pose a 

chronic risk to saltwater invertebrates. 

Table 23. Acute and Chronic RQs for Fish and Aquatic Invertebrates 

Crop Application 

Scenario Taxa Endpoint 

(mg) 

RQ (clear 

waters) 

High 

Photolysis 

RQ 

(turbid 

waters) 

Low 

photolysis 

LDPH 

Adjusted 

RQ (clear 

waters) 

Fast 

Photolysis 

LDPH 

Adjusted 

RQ 

(turbid 

waters) 

Slow 

photolysis 

Peppers

in

Florida

One aerial

application

at 0.375 lb

a.i./A

Freshwater

fish 93.8 <0.01 <0.01       

Saltwater fish 114 <0.01 <0.01 

Freshwater 

Invertebrate 60.4 <0.01 <0.01 
57 

Saltwater 

Crustacean 1 0.02 0.03 

Saltwater 

Mollusk 10.5 <0.01 <0.01 

Chronic 

Freshwater Fish 2.95 <0.01 0.01 0.13 0.26 

Chronic 

Saltwater Fish No data available 

Chronic 

Freshwater 

Invertebrate 

0.2 0.08 0.14 

Chronic 

Saltwater 

Crustacean* 

0.003 5.32 9.25 

*exceeds the chronic risk LOC (RQ≥1.0) for listed and non-listed species. 

The RQs for aquatic plants were calculated the same way as those for aquatic animals by using 

EECs derived from both fast photolysis rates in clear waters and slow photolysis rates in turbid 

waters. RQs for risk to vascular and nonvascular aquatic plants are presented in Table 24. In 

clear waters, only the nonvascular plant RQ for listed species exceeded the LOC of 1.0. In turbid 

waters the RQs for both listed vascular plants (RQ = 1.49) and nonvascular plants (RQ = 1.77) 

exceeded the LOC. . 

In conclusion, this analysis indicates that existing and proposed uses of sulfentrazone may result 

in adverse effects on listed species of vascular plants and nonvascular plants, although no 

nonvascular plants are currently listed. 

Table 24. RQs for Aquatic Plants and Algae 

Crop Application 

Scenario Taxa 

Endpoint 

(mg 

a.i./L) 

Fast 

photolysis 

(clear 

water) 

Peak 

EEC 

(mg) 

Slow 

photolysis 

(turbid 

water) 

Peak 

EEC 

(mg) 

RQ (clear 

waters) 

High 

Photolysis 

RQ 

(turbid 

waters) 

Low 

photolysis

Peppers 

in 

Florida 

One aerial 

application 

at 0.375 lb 

a.i./A 

NonListed 

Species 

(Vascular 

plant 

Endpoint) 

0.03 0.02 0.03 0.62 0.99 

NonListed 

Species 

(Algal 

Endpoint) 

0.03 0.02 0.03 0.6 0.92 
58 

Listed 

Species 

(Vascular 

plant 

Endpoint) 

0.02 0.02 0.03 0.9 1.5* 

Listed 

Species 

(Algal 

Endpoint) 

0.02 0.02 0.03 1.1* 1.8* 

*Exceeds the LOC (RQ≥1.0) for risk to plants. 

A. Non-target Terrestrial Animals 

RQs are calculated by dividing the terrestrial EECs by the appropriate acute or chronic toxicity 

endpoint. Since no mortality was observed at any dose level in acute avian toxicity studies, 

definitive values of the acute oral LD50 and subacute dietary LC50 were not available (i.e., LD50

and LC50 values were greater than the highest test dose). In order to screen for the potential of 

acute risk to birds, the highest treatment level in each study was used as the basis for acute risk 

estimation This makes the RQs conservative since the actual LD50 and LC50 values are above the 

highest tested dose and no mortality was observed in either of the studies. Therefore, these nondefinitive RQ values are expressed as “<” values. Although these non-definitive (“<”) RQ 

values do not define precise risk estimates they do provide useful information as a screen of 

potential acute risk (i.e., if all the non-definitive RQ values are below the LOC, then the 

likelihood of adverse effects from exposure to sulfentrazone is presumed to be low). 

Table 25 provides acute and chronic RQ values for birds based on dietary toxicity studies 

incorporating risk predicted in all size classes, and Table 26 provides additional acute RQs based 

on single-dose oral toxicity studies. All avian acute RQ values are <0.06 and are below the acute 

risk LOC for non-listed (0.5) and listed (0.1) birds. Chronic RQs, which are based on the 

definitive NOAEC for the bobwhite quail (10 ppm) ranged from 0.56 to 9.0 for upper-bound 

Kenega values for the highest application rate of 0.375 lbs a.i./A and 0.19 and 3.0 for the lowest 

application rate of 0.125 lbs a.i./A. The RQs derived from upper bound Kenega values from all 

application rates generated from the dietary categories of short grass, tall grass, broadleaf plants 

and arthropods all exceeded the chronic risk LOC of 1. Only the fruits/pods/seeds dietary 

category did not exceed the LOC for chronic risk. As birds serve as surrogates for reptiles and 

terrestrial-phase amphibians, chronic risk for these taxa is assumed as well. 

Chronic RQs, represented by mean Kenega values ranged from 0.26 to 3.2 for the highest 

application rate of 0.375 lbs a.i./A. The only category that did not exceed a LOC of 1.0 at two of 

the highest application rates (0.375 and 0.3 lbs a.i./A) in either the upper bound Kenega (90th

percentile) or the mean Kenega (50th percentile) was the Fruits/Pods/Seeds category. RQs 

derived from the mean Kenega for the next two application rates (0.25 and 0.2 lbs a.i./A) 

exceeded the chronic LOC of 1.0 in three and two of the dietary categories respectively. The 

RQs represented by the mean Kenega for the lowest application rate (0.125 lbs a.i./A) ranged 

from 0.09 to 1.06 with only the short grass category exceeding a LOC of 1.0. Because the mean 

Kenega is derived from the central tendency of the model with 50% of the predictions being 
59 

higher than the modeled value and 50% of the predictions being lower than the predicted value it 

is not recommended for use in making risk calculations because it is not sufficiently conservative 

to protect species of concern and is therefore not presented in Table 24. 

Table 25. Acute and Chronic Dietary-Based RQs for Birds

Application 

Rate (lb a.i. / A) 

Dietary-based RQs (Dietarybased EEC/LC50 or NOAEC) 

RQs 

Acute Chronic 

0.375 

Short Grass 0.02 9.00* 

Tall Grass 0.01 4.13* 

Broadleaf plants 0.01 5.06* 

Fruits/pods/seeds 0.00 0.56 

Arthropods 0.01 3.53* 

0.3 

Short Grass 0.01 7.20* 

Tall Grass 0.01 3.30* 

Broadleaf plants 0.01 4.05* 

Fruits/pods/seeds 0.00 0.45 

Arthropods 0.01 2.82* 

0.25 

Short Grass 0.01 6.00* 

Tall Grass 0.00 2.75* 

Broadleaf plants 0.01 3.38* 

Fruits/pods/seeds 0.00 0.38 

Arthropods 0.00 2.35* 

0.2 

Short Grass 0.01 4.80* 

Tall Grass 0.00 2.20* 

Broadleaf plants 0.00 2.70* 

Fruits/pods/seeds 0.00 0.30 

Arthropods 0.00 1.88* 

0.125 

Short Grass 0.01 3.00* 

Tall Grass 0.00 1.38* 

Broadleaf plants 0.00 1.69* 

Fruits/pods/seeds 0.00 0.19 

Arthropods 0.00 1.18* 

*Exceeds the chronic risk LOC (RQ≥1) 

Table 26. Acute Dose-Based RQs for Birds

Dose-based RQs 

 (Dose-based EEC/adjusted LD50) 

Avian Acute RQs 

Size Class (grams) 

20 100 1000 

Short Grass <0.06 <0.03 <0.01 
60 

Tall Grass <0.03 <0.01 0.00 

Broadleaf plants <0.04 <0.02 <0.01 

Fruits/pods 0.00 <0.00 0.00 

Arthropods <0.02 <0.01 0.00 

Seeds 0.00 0.00 0.00 

The acute toxicity endpoint for mammals was non-definitive, i.e., LD50>2855 mg/kg bw, and 

sulfentrazone is classified as practically non-toxic on an acute exposure basis. As described 

previously for birds, a non-definitive (“<”) acute RQ was calculated based on the highest dose 

tested (2855 mg a.i./kg). Table 27 provides chronic risk quotients (RQs) for mammals and 

Table 28 provides additional acute RQs based on single-dose oral toxicity studies. All of the 

mammalian acute RQs for uses with applications rates of 0.375 lb ai/A were <0.01. Thus, the 

analysis shows that acute RQs are below the LOC for risk to non-listed (0.5) and listed (0.1) 

species of mammals. The highest chronic RQ was 0.2 and less than the LOC (1.0) for chronic 

risk to listed and non-listed mammals. 

Table 27. Chronic Dietary-Based RQs for Mammals 

Dietary-based RQs 

(Dietary-based EEC/ 

NOAEC) 

Mammal RQs 

Short Grass 0.02 

Tall Grass 0.01 

Broadleaf plants 0.01 

Fruits/pods/seeds 0 

Arthropods 0.01 

Table 28. Acute and Chronic Dose-Based RQs for Mammals

Dose-based RQs 

(Dose-based 

EEC/LD50 or 

NOAEL) 

Small mammal 

15 

grams 

Medium mammal

35 

grams 

Large mammal 

1000 

grams 

Acute Chronic Acute Chronic Acute Chronic 

Short Grass <0.01 <0.20 <0.01 <0.17 <0.01 <0.09 

Tall Grass <0.01 <0.09 <0.01 <0.08 0.00 <0.04 

Broadleaf plants <0.01 <0.11 <0.01 <0.09 0.00 <0.05 

Fruits/pods <0.00 <0.01 0.00 <0.01 0.00 <0.01 

Arthropods <0.01 <0.08 0.00 <0.07 0.00 <0.04 

Seeds <0.00 <0.00 0.00 0.00 0.00 0.00 
61 

For the initial Tier 1 risk estimation to honey bees, two exposure routes are considered: dietary 

and contact. Table 29 summarizes the initial residue values expressed in units of μg a.i./bee per 

1 lb a.i./A. As discussed below, these values are adjusted to account for the application rate of 

the chemical. For generating RQs, dietary-based exposure values are compared to oral toxicity 

data for larvae and adult worker bees while contact exposure values are compared to acute 

contact toxicity data for adult worker bees. 

The initial screening-level RQs exceed the acute risk LOC of 0.4 for adult bees based on oral but 

not for adult contact exposures (Table 29). These RQs are based on non-definitive endpoints of 

>25.1 and >200 μg a.i./bee for oral and contact tests, respectively. However, there were no 

treatment-related mortalities observed in either study and based on lack of apparent toxicity in 

the oral and contact tests and the non-definitive nature of the RQs (less than values), the 

likelihood of adverse effects to bees from exposure to sulfentrazone is considered low. 

Therefore, additional refinement of the Tier 1 exposure estimates is not warranted. 

Table 29. Dietary and contact RQs for honey bees. 

Life 

Stage Exposure Type 

Dose 

(μg 

a.i./bee 

per 1 lb 

a.i./A)(1)

Sulfentrazone Dose for 

Max Application Rate 

(μg a.i./bee 

per 0.133 lb a.i./A) 

Acute 

RQ(2)(3)

Chronic 

RQ(3)

Adult Diet (nectar + 

pollen) 32.00 12.00 <0.48 n.a. 

Adult Direct contact 2.70 1.01 <0.01 n.a. 

(1) Source: USEPA 2012. Draft Pollinator Risk Assessment Framework

(2) Based on a 48-h acute oral LD50 of >25.1 ug ai/bee (MRID 44054902, 43678166) and acute contact LD50 of 

>200 ug ai/bee (MRID 43678166).

(3) Bolded value exceeds the acute risk LOC of 0.4

B. Non-target Terrestrial Plants 

Sulfentrazone is toxic to terrestrial plants. The TerrPlant model (v. 1.2.2) was used to calculate 

RQs for nontarget terrestrial plants in three scenarios, spray drift only, runoff and spray drift in 

upland/dry areas, and runoff and spray drift in wetland/semi-aquatic areas The model AgDrift 

was used to examine the impacts of spray drift on both listed and non-listed species (below). 

Terrestrial Plant RQs for important uses and application rates of sulfentrazone are given in Table 

30 and Table 31 for ground and aerial applications, respectively using the TerrPlant model.

Table 30. RQs for Risk to Nontarget Terrestrial Plants from Use of Sulfentrazone for 

ground applications.

Crop 

Single 

Max. 

Application 

Rate (lbs 

ai/A) 

Monocot RQ Values2

Spray Drift Only 

 Runoff and Runoff and 

Spray Drift Spray Drift 

(Dry Areas) (Semi-Aquatic 

Areas) 
62 

Nonlisted 

Species 

Listed 

Species 

Nonlisted 

Species 

Listed 

Species1

Nonlisted 

Species 

Listed 

Species1

Apple, Rhubarb, 

Turnip roots and 

tops, Sunflower 

Crop Subgroup 

20B,Spring 

Wheat,Succulent 

cowpea, Succulent 

lima beans, Tree 

nut Crop Group 14 

including, Citrus 

Crop, Small berry 

and fruit Crop 

Group 13-07,Nongrass animal feed 

Crop Group 

18,Head/Stem 

Brassica Subgroup 

5A,Leafy Greens 

Subgroup 

5B,Melon 

Subgroup 9A, 

Fruiting Vegetable 

Group 

8,Okra,Succulent 

Pea, Strawberry 

and Tuberous 

/Corm Vegetable 

Subgroup 1C, 

Sugarcane, 

Cabbage, Potato, 

Mint, Horseradish, 

Turf 

0.375 0.31 0.63 0.98 1.2 8.3 10.0 

Peanuts 0.3 0.78 0.95 0.25 0.5 6.7 8.1 

Sunflower/field 

corn/dry bean/dry 

pea, Peanuts 

incorporated up to 

2-4", Asparagus 

0.25 0.21 0.42 0.65 0.79 5.5 6.7 

Brassica, Corn, 

Wheat, Cowpea, 

Succulent pea, 

Lima bean

0.20 0.17 0.33 0.52 0.63 4.4 5.4 

Turf, including 

Golf Courses 0.125 0.52 1.04 0.54 0.66 3.0 3.6 

Crop 

Single 

Max. 

Application 

Rate (lbs 

ai/A) 

Dicot RQ Values2

Spray Drift Only 

 Runoff and Runoff and 

Spray Drift Spray Drift 

(Dry Areas) (Semi-Aquatic 

Areas) 

Nonlisted 

Species 

Listed 

Species 

Nonlisted 

Species 

Listed 

Species1

Nonlisted 

Species 

Listed 

Species1
63 

Apple, Rhubarb, 

Turnip roots and 

tops, Sunflower 

Crop Subgroup 

20B,Spring 

Wheat,Succulent 

cowpea, Succulent 

lima beans, Tree 

nut Crop Group 14 

including, Citrus 

Crop, Small berry 

and fruit Crop 

Group 13-07,Nongrass animal feed 

Crop Group 

18,Head/Stem 

Brassica Subgroup 

5A,Leafy Greens 

Subgroup 

5B,Melon 

Subgroup 9A, 

Fruiting Vegetable 

Group 

8,Okra,Succulent 

Pea, Strawberry 

and Tuberous 

/Corm Vegetable 

Subgroup 1C, 

Sugarcane, 

Cabbage, Potato, 

Mint, Horseradish, 

Turf 

0.375 7.2 8.5 2.1 3.8 17.4 31.9 

Peanuts 0.3 5.8 6.8 1.6 3.0 13.9 25.5 

Sunflower/field 

corn/dry bean/dry 

pea, Peanuts 

incorporated up to 

2-4", Asparagus, 

soybeans, potatoes, 

horseradish, 

melons, rhubarb, 

turnips 

0.25 4.8 5.7 1.4 2.5 11.6 21.3 

Brassica, Corn, 

Wheat, Cowpea, 

Succulent pea, 

Lima bean

0.20 3.9 4.6 1.1 2.0 9.3 17.0 

Turf, including 

Golf Courses 0.125 12.0 14.2 1.1 2.1 6.3 11.5 

1

 RQs which exceed the EPA’s level of concern for risk to nontarget terrestrial plants are shown in bold type. 

Table 31. RQs for Risk to Nontarget Terrestrial Plants from Use of Sulfentrazone for 

aerial applications.

Crop 

Single 

Max. 

Application 

Rate (lbs 

ai/A) 

Monocot RQ Values2

Spray Drift Only 

 Runoff and Runoff and 

Spray Drift Spray Drift 

(Dry Areas) 

(Semi-Aquatic 

Areas) 
64 

Nonlisted 

Species 

Listed 

Species

Nonlisted 

Species 

Listed 

Species1

Nonlisted 

Species 

Listed 

Species1

Soybeans, 

Sugarcane, 

Railroad, 

Highway, 

Roadside, 

Pipelines 

0.375 1.6 1.9 1.6 3.3 9.0 11 

Crop 

Single 

Max. 

Application 

Rate (lbs 

ai/A) 

Dicot RQ Values2

Spray Drift Only 

 Runoff and Runoff and 

Spray Drift Spray Drift 

(Dry Areas) 

(Semi-Aquatic 

Areas) 

Nonlisted 

Species 

Listed 

Species

Nonlisted 

Species 

Listed 

Species1

Nonlisted 

Species 

Listed 

Species1

Soybeans, 

Sugarcane, 

Railroad, 

Highway, 

Roadside, 

Pipelines 

0.375 36 43 3.4 6.3 18.8 34 

Monocots had lower RQs than dicots. At the highest application rate, the monocot RQs 

exceeded the LOC for only listed species in dry upland areas and for both non-listed and listed 

species in semi-aquatic areas. The RQs for the lower application rates did not exceed the LOC 

for monocots in the spray drift alone or the combined runoff and spray drift in dry areas scenario. 

The RQs for monocots in lowland, semi aquatic areas, exceeded the LOC for all the maximum 

listed application rates for sulfentrazone. The highest RQs for monocots were determined to be 

8.3 and 10.0 for non-listed and listed species, respectively, in semi-aquatic areas. The RQs for 

dicots, in contrast, exceeded the LOCs at every application rate in every scenario evaluated. 

Similar to monocots, the highest RQ values for dicots are also expected in semi-aquatic areas 

exposed to both spray drift and runoff. The highest RQ for dicots was 17.4 and 31.9 for nonlisted and listed species, respectively. 

For aerial applications, with different model parameters than ground applications (Table 31), the 

RQs exceeded the LOCs for every scenario for both monocots and dicots. The highest RQs for 

monocots were in semi-aquatic areas with both spray drift and runoff while for dicots, the 

highest RQs were from spray drift alone. The highest RQs for monocots were 9.0 and 11 for 

non-listed and listed species, respectively, in semi-aquatic areas. The highest RQs for dicots 

were 36 and 43 for non-listed and listed species, respectively, for spray drift alone. 

To further analyze the potential risk from sulfentrazone use to non-target plants, the AgDrift 

model was used to predict spray drift deposition, and to determine the distance from the edge of 

the treated site where the risk from spray drift alone is equal the LOC for listed and non-listed 

plants. This was done by predicting the distance where the spray drift equals the vegetative vigor 

EC25 for evaluating risk to non-listed plants, and by predicting the distance where the spray drift 

equals the vegetative vigor NOAEL for evaluating risk to listed plants. Beyond these distances, 
65 

the risk from spray drift alone is not expected to exceed the LOC. It is important to recognize, 

though, that risk from runoff is not considered in this analysis. In this analysis, since 

sulfentrazone is used in ground applications, the model was run with the default assumptions of a 

very fine to fine spray drift droplet size and high boom height. For pre-plant/pre-emergent 

applications, low boom applications are likely typical; whereas, for post-emergence applications, 

either low or high boom applications may be common. 

Results from this analysis are given in Table 32, Table 33, Table 34, and Table 35. For ground 

applications (Table 30a) using a high boom, distances for protecting the most sensitive nonlisted plants ranged from 6.56 feet for corn to greater than 1000 feet for cucumber. Distances for 

protection of the most sensitive listed plants ranged from 19.7 feet for corn to greater than 1000 

ft for cucumber. For ground applications using a low boom, distances for protecting the most 

sensitive non-listed plants ranged from 3.28 feet for corn to greater than 731 feet for cucumber. 

Distances for protection of the most sensitive listed plants ranged from 6.56 feet for corn to 846 

ft for cucumber. For aerial applications (Tables 28 and 29) with very fine to fine particle sizes, 

50% of the end points for non-listed species exceeded 1000 ft buffer and 70% of the end points 

for listed species exceeded the 1000 ft buffer. From fine to coarse spray scenarios, only 30% of 

the endpoints resulted in distances that exceeded a 1000 ft buffer. The endpoint utilizing the 

most sensitive dicot, i.e., cucumber, exceeded the 1000 ft buffer in every spray particle size 

scenario. 

Table 32. Distance from Edge of Field of Risk to non-target terrestrial Plants, Based on 

AgDrift Prediction of Spray Drift with a very fine to fine particle size and a high boom 

dispersal.

Plant Species 

Vegetative Vigor 

Endpoints (lbs 

a.i. / A) High Boom Low Boom 

EC25 NOAEC

Distance 

in feet 

for Nonlisted 

Species 

Distance 

in feet 

for 

Listed 

Species 

Distance 

in feet 

for Nonlisted 

Species 

Distance 

in feet 

for 

Listed 

Species 

Monocots 

Corn 0.18 0.056 6.56 19.68 3.28 6.56 

Oat 0.033 0.006 29.53 154.2 13.12 55.77 

Onion3 0.012 0.006 78.74 154.2 29.53 55.77 

Ryegrass 0.045 0.019 22.97 52.49 9.84 19.68 

Dicots 

Cabbage 0.011 0.006 85.3 154.2 32.81 55.77 

Lettuce 0.025 0.006 39.37 154.2 16.4 55.77 

Tomato 0.012 0.0013 78.74 547.89 29.53 305.11 

Radish 0.057 0.019 19.68 52.49 6.56 19.68 

Soybean 0.0044 0.0013 206.69 547.89 78.74 305.11 

Cucumber3 0.0005 0.00044 Out of 

range2

Out of 

range2 731.62 846.45 

1 The endpoints in the vegetative vigor studies were determined to be more sensitive to sulfentrazone than endpoints from 

the seedling emergence studies. 
66 

2 Out of range denotes distances greater than 1000 feet from the edge of field 3

Bolded values represent the most sensitive endpoints. 

Table 33. Distance from Edge of Field of Risk to Listed Terrestrial Plants, Based on 

AgDrift Prediction of Spray Drift with a fine to medium/coarse particle size and a high 

boom dispersal. 

Plant Species 

Vegetative Vigor 

Endpoints (lbs a.i. 

/ A) High Boom Low Boom 

EC25 NOAEC

Distance 

in feet 

for Nonlisted 

Species 

Distance 

in feet 

for 

Listed 

Species 

Distance 

in feet 

for Nonlisted 

Species 

Distance 

in feet 

for 

Listed 

Species 

Monocots 

Corn 0.18 0.056 3.28 3.28 3.28 3.28 

Oat 0.033 0.006 6.56 36.09 3.28 19.68 

Onion1 0.012 0.006 16.4 36.09 9.84 19.68 

Ryegrass 0.045 0.019 6.56 9.84 3.28 6.56 

Dicots 

Cabbage 0.011 0.006 19.68 36.09 9.84 19.68 

Lettuce 0.025 0.006 9.84 36.09 6.56 19.68 

Tomato 0.012 0.0013 16.4 236.22 9.84 141.07 

Radish 0.057 0.019 3.28 9.84 3.28 6.56 

Soybean 0.0044 0.0013 52.49 236.22 29.53 141.07 

Cucumber1 0.00052 0.00044 600.39 698.81 433.07 518.37 

1

Bolded values represent the most sensitive endpoints.

Table 34. Distance from Edge of Field of Risk to non-target terrestrial plants, based on 

AgDrift Prediction of Spray Drift with aerial application with particle size scenarios of 

very fine to fine and fine to medium. 

    Vegetative Vigor 

   

Endpoints (lbs a.i. 

/ A) 

Aerial (very fine to 

fine) 

Aerial (fine to 

medium) 

Plant 

Species EC25 NOAEC

Distance 

in feet 

for 

Nonlisted 

Species 

Distance 

in feet 

for 

Listed 

Species 

Distance 

in feet 

for 

Nonlisted 

Species 

Distance 

in feet 

for 

Listed 

Species 

Monocots 

Corn 0.18 0.056 3.28 187.01 3.28 65.62 

Oat 0.033 0.006 357.61 Out of 

range 

111.55 620.07 

Onion3 0.012 0.006 Out of 

range2

Out of 

range2 295.27 620.07 

Ryegrass 0.045 0.019 242.78 731.62 78.74 183.72 
67 

Dicots 

Cabbage 0.011 0.006 Out of 

range2

Out of 

range2 318.24 620.07 

Lettuce 0.025 0.006 505.24 Out of 

range2 144.36 620.07 

Tomato 0.012 0.0013 Out of 

range2

Out of 

range2 295.27 Out of 

range2

Radish 0.057 0.019 180.44 731.62 62.34 183.72 

Soybean 0.0044 0.0013 Out of 

range2

Out of 

range2 990.8 Out of 

range2

Cucumber3 0.00052 0.00044 Out of 

range2

Out of 

range2

Out of 

range2

Out of 

range2

The endpoints in the vegetative vigor studies were determined to be more sensitive to sulfentrazone than 

endpoints from the seedling emergence studies. 

2

 Out of range denotes distances greater than 1000 feet from the edge of field 3

Bolded values represent the most sensitive endpoints. 

Table 35. Distance from Edge of Field of Risk to Listed Terrestrial Plants, Based on 

AgDrift Prediction of Spray Drift with aerial application with particle size scenarios of 

medium to coarse and coarse to very coarse.

Plant Species

Vegetative Vigor 

Endpoints (lbs a.i. 

/ A) 

Aerial (medium to 

coarse) 

Aerial ( coarse to 

very coarse) 

EC25 NOAEC

Distance 

in feet 

for Nonlisted 

Species 

Distance 

in feet 

for 

Listed 

Species 

Distance 

in feet 

for Nonlisted 

Species 

Distance 

in feet 

for 

Listed 

Species 

Monocots 

Corn 0.18 0.056 0 19.68 0 16.4 

Oat 0.033 0.006 36.09 209.97 29.53 141.07 

Onion 0.012 0.006 118.11 209.97 82.02 141.07 

Ryegrass 0.045 0.019 26.25 78.74 19.68 49.21 

Dicots 

Cabbage 0.011 0.006 127.95 209.97 85.3 141.07 

Lettuce 0.025 0.006 65.62 209.97 39.37 141.07 

Tomato 0.012 0.0013 118.11 Out of 

range2 82.02 534.77 

Radish 0.057 0.019 19.68 78.74 16.4 49.21 

Soybean 0.0044 0.0013 265.74 Out of 

range2 180.44 534.77 

Cucumber 0.00052 0.00044 Out of 

range2

Out of 

range2

Out of 

range 

Out of 

range2

2

 Out of range denotes distances greater than 1000 feet from the edge of field 
68 

Based on the screening-level assessment, uses of sulfentrazone are predicted to pose risk to nontarget terrestrial plants, regardless of the application method and timing. All uses with the 

application rate of 0.375 lb a.i./A potentially may result in harm to listed plants. The analyses 

indicate that risk to terrestrial plants is greater for ground high boom and aerial applications than 

ground low boom applications. 

C. Review of Incident Data 

The Ecological Incident Information System (EIIS), which is maintained by the Agency’s Office 

of Pesticide Programs, was searched in January 2014 to determine if ecological incidents have 

been reported for sulfentrazone. A total of 18 incidents, all involving plants, were associated 

with the use of sulfentrazone. The eighteen incidents of damage to nearby vegetation involved 

sulfentrazone use in Minnesota, Iowa, Arkansas, and Oregon (the lone industrial site record). 

Fifteen of the incidents resulted from uses on soybeans with impacts ranging from damage to 40 

acres in Worth, Iowa. to 300 acres in Arkansas. The highest impacts, where uses impacted 500 

acres occurred in Grundy, Iowa from a non-specified use of sulfentrazone. Many of the 

incidents attributed the off-site movement of residues to spray drift, while a few attributed it to 

runoff. 88 percent of the incidents resulted from registered uses and 100% involved adverse 

impacts to plants. Only two small incidents (1 acre, and partial loss of 8 acres) resulted from 

uses that were classified as undetermined. 

The American Bird Conservancy (ABC) Avian Incident Monitoring System (AIMS) was 

searched in January 2014 and contained no incidents associated with sulfentrazone (ABC, 2007). 

A search of the Incident Database System (IDS) maintained by OPP’s Information Technology 

and Resource Management Division (ITRMD) conducted on February 20, 2014 yielded 80 

incidents for sulfentrazone involving plants, some of which are likely the same as those reported 

in the EIIS. Because of limitations in the incident reporting system, the lack of additional 

incident reports cannot be construed as an accounting of all of incidents from the registered use 

of sulfentrazone. 

A detailed listing of individual incidents associated with sulfentrazone spray drift, runoff, and 

carryover exposure is provided in Appendix D. 

D. Probit Slope Response Analysis of LOC Values and Acute RQ Values 

The chance of individual effects was not evaluated using the IECv1.1.xls spreadsheet because 

acute toxicity tests with animals did not yield definitive LD50 or LC50 values through probit 

analysis for birds, mammals, fish, and saltwater invertebrates. However, since the acute RQs for 

these taxa are known to be less than 0.01 for birds, mammals, fish, and freshwater invertebrates, 

and less than 0.02 for saltwater crustaceans, the chance of mortality to an individual of any of 

these taxa is considered low. 
69 

V. RISK DESCRIPTION 

A. Risk Characterization 

Because of its high mobility and persistence in soil, sulfentrazone is prone to off-site 

movement via runoff, which may result in contamination of nearby terrestrial and aquatic 

habitats. This prominent route of exposure would exist regardless of whether 

sulfentrazone is applied aerially or with ground equipment. This is reflected in the fact 

that aquatic EECs for ground applications were only slightly lower than comparable 

EECs for aerial applications. 

1. Summary of Risk 

Based on this preliminary assessment, there are potential risks to listed and non-listed plants 

(terrestrial and aquatic) from exposure to sulfentrazone use in ground applications (on Apple, 

Rhubarb, Turnip roots and tops, Sunflower Crop Subgroup 20B,Spring Wheat, Succulent 

cowpea, Succulent lima beans, Tree nut Crop Group 14 including, Citrus Crop, Small berry and 

fruit Crop Group 13-07,Non-grass animal feed Crop Group 18,Head/Stem Brassica Subgroup 

5A,Leafy Greens Subgroup 5B,Melon Subgroup 9A, Fruiting Vegetable Group 8,Okra,Succulent 

Pea, Strawberry and Tuberous /Corm Vegetable Subgroup 1C, Sugarcane, Cabbage, Potato, 

Mint, Horseradish, Turf at the 0.375 lb a.i. / A application rate, on peanuts at the 0.3 lb a.i./A 

application, on Sunflower/field corn/dry bean/dry pea, Peanuts incorporated up to 2-4", 

Asparagus, soybeans, potatoes, horseradish, melons, rhubarb, turnips at the 0.25 lb a.i./A 

application rate, on Brassica at the 0.2 lb a.i./A application rate, and on Corn, Wheat, Cowpea, 

Succulent pea, Lima bean at 0.19 lb a.i. /A application rates) and in aerial applications (on 

soybeans, sugarcane, railroads, highways, roadsides, and pipelines.) Risk is posed to all types of 

nontarget plants, including monocots, dicots, aquatic vascular plants, and aquatic nonvascular 

plants. Use of sulfentrazone is not expected to cause direct adverse effects to any listed species 

of terrestrial animals, but may cause indirect effects to listed animals through impacts on 

vegetation and plant food sources. 

2. Risk to Aquatic and Terrestrial Animals 

Sulfentrazone is a light dependent peroxidizing herbicide (LDPH). The mode of action of 

sulfentrazone blocks chlorophyll and heme biosynthesis and results in endogenous accumulation 

of photo-toxic porphyrins in plants but may also be toxic to animals. Following EFED guidance 

for LDPH chemicals, an interim 29X toxicity adjustment factor was applied to the fish early life 

stage study to account for potential enhanced toxicity when organism are exposed to light in 

clear water columns (U.S. EPA, 2010). While the chronic RQs for fish increased as a result of 

this factor, they did not exceed the established chronic risk LOCs for either listed or non-listed 

species. Aquatic environments near use sites may however frequently be sufficiently turbid or 

shaded so as not to warrant incorporation of this factor. In these turbid environments however, 

sulfentrazone is expected to be more persistent and may accumulate resulting in higher EECs and 

exposures of aquatic organisms. While models of these turbid environments result in enhanced 

exposures as a result of decreased photolysis rates, the EECs still do not result in significant 

changes in risk estimates as demonstrated by the maximum change in RQ increasing from 0.08 
70 

to 0.14 for chronic toxicity to freshwater invertebrates and from 5.3 to 9.2 for chronic toxicity to 

estuarine/marine crustaceans. 

 

Sulfentrazone has low acute and chronic toxicity to mammals, terrestrial arthropods, fish, and 

aquatic freshwater invertebrates. Chronic risk was found for birds. There was an 8% reduction 

in body weight at the highest concentration tested establishing a LOAEC of 100 ppm. The 

NOAEC in this study (MRID 43355901) to establish the chronic risk quotients that exceeded the 

LOCs was 10 ppm. The wide spacing of experimental doses establishing the NOAEC and the 

LOAEC results in some uncertainty in this risk determination. Additionally, there were not any 

other statistically significant differences in any of the other endpoints. The wide spacing to the 

experimental doses and lack of additional effects during the experiment suggests that the 

NOAEC may in fact not be ten times lower than the LOAEC. 

 Sulfentrazone has a high acute toxicity to estuarine/marine crustaceans and may result in chronic 

risk to estuarine invertebrates as indicated by the chronic RQs of 5.3 and 9.2 in clear and turbid 

environments respectively. Based on the screening-level risk assessment the current and 

proposed uses of sulfentrazone pose low risk to most aquatic animals; however, they may 

potentially pose chronic risk to both listed and non-listed estuarine/marine invertebrates. 

Sulfentrazone is expected to pose low risk to all terrestrial animals, and is not expected to cause 

significant direct effects to either non-listed or listed species of terrestrial animals. This is 

supported by the lack of incident data involving animals for sulfentrazone. 

There is uncertainty regarding the potential for risk to honey bees given the indeterminate RQ 

(RQ<0.48) for oral exposure to sulfentrazone because this value is based on a non-definitive 

endpoint (>25.1 μg a.i./bee). Given the lack of toxic effects observed in both contact and oral 

toxicity studies, these data suggest that sulfentrazone does not pose a significant risk to 

honeybees and other terrestrial invertebrate taxa. It cannot be assumed, however, that lack of 

toxicity in the honeybee precludes direct toxicity to all terrestrial invertebrate taxa. Despite the 

lack of direct effects to terrestrial and aquatic animals, indirect adverse effects are possible 

because of sulfentrazone’s toxicity to plants and consequent effects on primary 

productivity/habitat. Toxicity to plants may reduce the supply of plant food, which is the basis of 

the ecological food web in both aquatic and terrestrial ecosystems. In addition, the toxicity to 

plants may alter plant communities, especially those near treated fields, which may result in 

ecological harm to some animal species. 

3. Risk to Terrestrial and Aquatic Plants 

Despite the relatively low use rates of this herbicide, the phytotoxicity of sulfentrazone 

results in the conclusion that all uses pose potential risk to non-target terrestrial plants. 

The risk assessment indicates that all uses of sulfentrazone exceed the LOCs for nonlisted and listed terrestrial plants and listed aquatic plants. While sulfentrazone may only 

be applied once per year, residues in soil and water may remain at phytotoxic levels for 

long periods of time. In addition, sulfentrazone has little binding potential to organic 

material in the soil, and thus is prone to movement in runoff. Both of these factors 

increase the potential for residues to be transported from the use site into terrestrial and 

aquatic habitats where non-target plants can be exposed as well as accumulate in remote 
71 

receiving water bodies that are shaded from light (either as turbid water columns or other 

light blocking entities (e.g., trees, emergent plants).

Sulfentrazone also has a high rate of photolysis and degrades rapidly when exposed to 

light. Receiving water bodies, adjacent to use sites, may be turbid retention ponds or 

shaded streams, while clearer water bodies farther afield may receive sulfentrazone due 

to its high persistence and mobility in soils. In turbid waters, uses of sulfentrazone may 

potentially pose risk to listed species of non-vascular and vascular plants (RQ = 1.5 and 

1.8). In clear water columns with rapid degradation from photolysis, there is still risk to 

listed non-target species (RQ = 1.1). 

Incident data also support the potential for sulfentrazone residues to move off-site and to 

harm non-target plants. All incidents involved plants and is consistent with the 

conclusion that sulfentrazone poses a potential risk to non-target terrestrial plants. 

4. Risk to Endangered Species 

At the current stage of the Registration Review process, it is premature to make effects 

determinations for listed species until further scientific analysis and refinements are conducted, 

based on recommendations received from the National Academy of Sciences’ (NAS) National 

Research Council (NRC) April 2013 report, available at 

http://www.nap.edu/catalog.php?record_id=18344. The NAS report outlines recommendations 

on specific scientific and technical issues related to the development of pesticide risk 

assessments that are compliant with the Endangered Species Act (ESA) and the Federal 

Insecticide, Fungicide, and Rodenticide Act (FIFRA). 

The EPA along with the U.S. Fish & Wildlife Service (USFWS), the National Marine Fisheries 

Service (NMFS) (collectively, the Services), and the U.S. Department of Agriculture (USDA), 

released a summary of their implementation plan for assessing risks of pesticides to listed species 

ahead of the stakeholder workshop held on November 15, 2013. This plan was developed in 

response to the NAS’ recommendations, including a common approach to risk assessment as a 

way of addressing scientific differences between EPA and the Services. During the workshop, 

the agencies received feedback from the public on the interim scientific approaches that were 

developed as part of the initial implementation of the NAS recommendations. These approaches 

will be jointly implemented and vetted as part of a phased iterative process. Once fully vetted, 

EPA will further refine the listed species effects determination portion of this risk assessment. 

To make effects determinations for individual listed species, useful refinements may include, but 

are not limited to, analyses of: 1) more detailed, species-specific ecological and biological data; 

2) more detailed and accurate information on sulfentrazone use patterns; and 3) sub-county level 

spatial proximity data for the co-occurrence of potential effects areas and listed species and any 

designated critical habitat. Examples of such refinements are described below. 

EFED is currently developing tools that are expected to further refine the assessment and are 

designed to support effects determinations for individual listed species and their designated 

critical habitat (where applicable). Scientific information obtained from the U.S. Fish and 

Wildlife Service (USFWS), the National Marine Fisheries Service (NMFS), and other reliable 
72 

sources are being collated by EFED to address all currently listed species. The information will 

be stored in an Office of Pesticide Programs Pesticide Registration Information SysteM (PRISM) 

knowledgebase. The listed species knowledgebase will consist of an information repository that 

houses biological and behavioral information relevant to individual species (e.g., habitat, diet, 

and life history, including specific temporal and spatial associations) and a document repository 

that contains supporting documents (e.g., USFWS recovery plans) and electronic information 

(e.g., GIS data files). For terrestrial taxa, biological information relevant to the assessment (e.g., 

diet and body weight) will be used to parameterize exposure estimates using a method consistent 

with currently used methods in the T-REX and T-HERPS models. 

Refinements will also include more detailed analyses of the registered uses and specific use 

patterns that result in either “Likely to Adversely Affect” (LAA) or “Not Likely to Adversely 

Affect” (NLAA) determinations for federally listed species. The analyses may include more 

information on where, when, and how sulfentrazone is used on all use sites. Actual usage data 

(when available) and national land-cover datasets that indicate potential use sites [e.g., National 

Land Cover Dataset (NLCD), Cropland Data Layer (CDL)] may be used to support a more 

refined analysis of where sulfentrazone is reasonably expected to be used. Similarly, 

refinements on the timing of applications and a more in-depth exploration of agronomic practices 

for sulfentrazone may be included as part of the refinement. Similarly, refinements for the timing 

of applications and how sulfentrazone is used may be based on the analysis of actual usage data, 

beyond what were available at the time of the screening-level assessment, and a more in-depth 

exploration of agronomic practices. 

The refinements based on individual species data; additional, detailed usage information, when 

available; and recommendations from the NRC report are expected to help to more accurately 

identify potential areas of effect and to better inform effects and habitat determinations for listed 

species and any designated critical habitats. 

B. Assumptions and Limitations 

1. Endocrine Disruption 

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse 

outcomes from exposure to chemicals. Collectively, these studies include acute, subchronic and 

chronic toxicity, including assessments of carcinogenicity, neurotoxicity, developmental, 

reproductive, and general or systemic toxicity. These studies include endpoints which may be 

susceptible to endocrine influence, including effects on endocrine target organ histopathology, 

organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, reproductive loss, 

and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and 

chronic studies that assess growth, developmental and reproductive effects in different 

taxonomic groups. As part of its most recent registration decision for sulfentrazone, EPA 

reviewed these data and selected the most sensitive endpoints for relevant risk assessment 

scenarios from the existing hazard database. However, as required by FFDCA section 408(p), 

sulfentrazone is subject to the endocrine screening part of the Endocrine Disruptor Screening 

Program (EDSP). 

EPA has developed the EDSP to determine whether certain substances (including pesticide 
73 

active and other ingredients) may have an effect in humans or wildlife similar to an effect 

produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator 

may designate.” The EDSP employs a two-tiered approach to making the statutorily required 

determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a 

chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal 

systems. Chemicals that go through Tier 1 screening and are found to have the potential to 

interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA 

will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 

testing is designed to identify any adverse endocrine-related effects caused by the substance, and 

establish a dose-response relationship between the dose and the E, A, or T effect. 

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between 

October 2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 

chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. A second list 

of chemicals identified for EDSP screening was published on June 14, 20135

 and includes some 

pesticides scheduled for registration review and chemicals found in water. Neither of these lists 

should be construed as a list of known or likely endocrine disruptors. 

For further information on the status of the EDSP, the policies and procedures, the lists of 

chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our 

website.6

2. Uncertainties Related to Data Limitations 

Sulfentrazone is a light-dependent peroxidizing herbicide (LDPH). LDPHs are a unique class of 

chemicals that can be more toxic in the presence of ultraviolet (uV) light. Several studies have 

documented enhanced toxicity of LDPHs to fish in the presence of uV light when compared to 

the toxicity observed under standard lighting (U.S. EPA, 2010). Given that aquatic organisms are 

likely exposed simultaneously to LDPH and uV light in natural settings, concerns have been 

raised that standard laboratory studies may underestimate the toxicity of LDPH in the field. In 

the absence of chemical specific data on LDPH toxicity under enhanced uV lighting, an 

uncertainty factor of 29X (per EFED guidance) was applied to the chronic fish toxicity study. 

Additionally since the uncertainty factor is based on data from other LDPH chemicals, there is 

uncertainty with the chronic fish (freshwater) toxicity endpoint. Additionally, there is 

uncertainty as to whether enhanced sensitivity could be observed in other taxa such as aquatic 

invertebrates, birds, mammals, and also plants. While the terrestrial plant studies were 

conducted in greenhouse settings, the toxicity data may not be conservative because the 

greenhouse plants did not receive full sunlight. 

In addition, chronic toxicity data are not available for estuarine/marine fish. In lieu of these data, 

an ACR comparing freshwater fish to marine estuarine fish would be used. Since the freshwater 

fish (i.e., rainbow trout) had a non-definitive endpoint for the acute study this was not possible. 

An early life stage study with a freshwater fish under modified lighting (i.e., enhanced uV) with a 

 

5

 See http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPPT-2009-0477-0074 for the final second list of 

chemicals. 6

 http://www.epa.gov/endo/ 
74 

low light “reference treatment” and a estuarine/marine fish (sheepshead minnow; Cyprinodon 

variegatus) conducted under both standard low light designs and modified lighting (i.e., 

enhanced uV) with a low light “reference treatment” would help to reduce the uncertainty in this 

assessment by supplying a chronic endpoint for an estuarine/marine fish and also data for a 

chemical-specific LDPH adjustment factor 

Additionally, an ACR was used to estimate chronic NOAEC for the mysid shrimp. The use of 

an ACR introduces uncertainty as it represents an unbounded measure of risk. The ACR 

compared the acute and chronic toxicity of the freshwater invertebrate D. magna to that of the 

mysid shrimp. The large difference (60X) in sensitivity in acute toxicity of the daphnid and 

mysid as well as the enhanced sensitivity of the daphnid from chronic exposures resulted in a 

large ACR factor (302) that impacted the risk conclusions regarding potential chronic risk for 

estuarine/marine invertebrates. Without more data on the chronic sensitivity of estuarine/marine 

invertebrates it is difficult to discern the likelihood and magnitude of adverse effects to 

estuarine/marine invertebrates for the use of sulfentrazone. 

Currently, toxicity studies on amphibians and reptiles are not required for pesticide registration. 

The Agency uses fish as surrogates for aquatic-phase amphibians and birds as surrogates for 

terrestrial-phase amphibians and reptiles. If other species are more or less sensitive to 

sulfentrazone than the surrogates, risks may be under- or overestimated, respectively. The 

Agency is not limited to a base set of surrogate toxicity information in establishing risk 

assessment conclusions though, and also considers toxicity data on non-standard test species 

when available. Further research is needed to determine whether, in general, reptiles and 

terrestrial-phase amphibians are suitably represented by bird species in assessing risks for 

sulfentrazone and whether fish are an appropriate surrogate for aquatic-phase amphibians. 

3. Routes of Exposure 

Dietary Exposure 

Screening-level risk assessments for spray applications of pesticides assume that 100% of the 

diet is relegated to single food types foraged only from treated fields. These assumptions are 

likely to be conservative for many species and will tend to overestimate potential risks. The 

assumption of 100% diet from a treated area may be realistic for acute exposures, but long-term 

exposures modeled as single food types composed entirely of material from a treated field is 

uncertain. 

Dermal Exposure 

The screening assessment does not consider sulfentrazone dermal exposure to birds and 

mammals. The Agency is actively pursuing modeling techniques to account for dermal exposure 

via direct application of spray and by incidental contact with contaminated vegetation, soil and 

water. 

4. Species sensitivity 

Although the screening risk assessment relies on a selected toxicity endpoint from the most 

sensitive species tested, it does not necessarily mean that the selected toxicity endpoints reflect 
75 

sensitivity of the most sensitive species existing in a given environment. The relative position of 

the most sensitive species tested in the distribution of all possible species is a function of the 

overall variability among species to a particular chemical. The relationship between the 

sensitivity of the most sensitive tested species versus wild species (including listed species) is 

unknown and a source of significant uncertainty. In addition, in the case of listed species, there is 

uncertainty regarding the relationship of the listed species' sensitivity and the most sensitive 

species tested. 

Organisms consume a variety of dietary items and may exist in a variety of sizes at different life 

stages. For foliar applications of liquid formulations, T-REX estimates exposure for the 

following dietary items: short grass, tall grass, broadleaf plants/small insects, fruits/pods/seeds/ 

large insects, and seeds for granivores. Birds (used as a surrogate for amphibians and reptiles), 

and mammals, consume all of these items. The size classes of birds represented in T-REX are 

the small (20 g), medium (100 g), and large (1000 g). The size classes for mammals are small 

(15 g), medium (35 g), and large (1000 g). EECs are calculated for the most sensitive dietary 

item and size class for birds (surrogate for terrestrial-phase amphibians and reptiles) and 

mammals. Table 36 shows the percentages of the EECs and RQs of the various dietary classes 

for each size class as compared to the most sensitive dietary class (short grass) and size class 

(small mammal or bird). This information could be used to further characterize potential risk 

that is specific to the diet of birds and mammals. For example, if a mammal only consumes 

broadleaf plants and small insects and the RQ was 100 for small mammals consuming short 

grass, the RQ for small mammals that only consumed broadleaf plants and small insects would 

be 56 (100 x 0.56). 

Table 36. Percentage of EEC or RQ for the Specified Dietary Items and Size Classes as 

Compared to the EEC or RQ for The Most Sensitive Dietary Items (Short Grass) and Size 

Class (Small Bird or Small Mammal) 

Dietary Items Percentage of EECs or RQs for the Specified Dietary Items and Size Class as compared to 

the EEC or RQ for Small Birds1 or Small Mammals Consuming Short Grass

Birds: Dose Based EECs and RQs 

Small, 20 g Mid, 100 g Large, 1000 g 

 EEC RQ EEC RQ EEC RQ 

Short Grass 100% 100% 57% 45% 26% 14% 

Tall Grass 46% 46% 26% 21% 12% 7% 

Broadleaf 

plants/small 

Insects 

56% 56% 32% 25% 14% 8% 

Fruits/pods/see

ds/large 

insects 

6% 6% 4% 3% 2% 1% 

Granivores 1% 1% 1% 1% 0.4% 0.2% 

Mammals: Dose-Based EECs and RQs 

Small, 15 g Mid, 35 g Large, 1000 g 

 EEC RQ EEC RQ EEC RQ 

Short Grass 100% 100% 69% 85% 16% 46% 

Tall Grass 46% 46% 32% 39% 7% 21% 
76 

Dietary Items Percentage of EECs or RQs for the Specified Dietary Items and Size Class as compared to 

the EEC or RQ for Small Birds1 or Small Mammals Consuming Short Grass

Broadleaf 

plants/small 

Insects 

56% 56% 39% 48% 9% 26% 

Fruits/pods/see

ds/large 

insects 

6% 6% 4% 5% 1% 3% 

Granivores 1% 1% 1% 1% 0.2% 0.6% 

Mammals and Birds: Dietary-based EECs and RQs for all Size Classes2

Short Grass 100% 

Tall Grass 46% 

Broadleaf 

plants/sm 

Insects 

56% 

Fruits/pods/see

ds/lg insects 6% 

1 The percents of the maximum RQ shown here for birds are based on the Agency’s default avian scaling factor of 1.15. 2 Percentages for dose-based chronic EECs and RQs for mammals are equivalent to the acute dose-based EECs and RQs. 

In the risk assessment, RQs were only calculated for the most sensitive dietary class relevant to 

the organisms assessed. For most organisms, insufficient data are available to conclude that 

birds or mammals may not exclusively feed on a dietary class for at least some time period. 

However, most birds and mammals likely consume a variety of dietary items and thus the RQ 

may overestimate risk to those organisms. Additionally, some organisms will not feed on all of 

the dietary classes, e.g., many amphibians would only consume insects and not any plant 

material. 

5. Sub-lethal Effects 

When assessing acute risk, the screening risk assessment relies on the acute mortality endpoint as 

well as a suite of sub-lethal responses to the pesticide, as determined by the testing of species 

response to chronic exposure conditions and subsequent chronic risk assessment. Consideration 

of additional sub-lethal data is exercised on a case-by-case basis and only after careful 

consideration of the nature of the sub-lethal effect measured and the extent and quality of 

available data to support establishing a plausible relationship between the measure of effect (sublethal endpoint) and the assessment endpoints of impaired survival, growth and/or reproduction. 

However, the full suite of sub-lethal effects from valid open literature studies is considered for 

the characterization purposes. 

To the extent to which sub-lethal effects are not considered in this assessment, the potential direct 

and indirect effects of sulfentrazone on listed species may be underestimated. 

6. Other Uncertainties in Risk Conclusions 

a) Sulfentrazone is both persistent and highly mobile, two factors that increase the potential for 

sulfentrazone to accumulate in receiving water bodies in significant quantities that may 
77 

impact plants and animals. Sulfentrazone also has a high rate of photolysis in clear water 

column. These chemical characteristics require a more detailed characterization of receiving 

water bodies, specifically the light environments of receiving water bodies, in order to further 

refine the risk conclusions. Sulfentrazone is expected to be more persistent in lower light 

environments that are characteristic of shaded bodies of water or turbid water columns. If 

turbid or shaded receiving waters, or groundwater derived irrigation water where residues 

may have leached, are used for irrigation purposes, sulfentrazone may additionally pose risk 

to the crops that are being irrigated. 

b) In order to make effects determinations for individual species, useful refinements may 

include analyses of 1) more detailed, species-specific ecological and biological data; 2) more 

detailed and accurate information on sulfentrazone use patterns; and 3) sub-county level 

spatial proximity data for the co-occurrence of potential effects areas and listed species and 

any designated critical habitat. 

VI. RISK CONCLUSIONS 

Sulfentrazone, when used in accordance with current labels, may result in contamination of 

ecosystems and adverse effects upon the survival, growth, and reproduction of non-target 

terrestrial and aquatic organisms, including listed species. 

Conclusions of the potential of use of sulfentrazone to cause direct and indirect effects to nonlisted and listed species of various taxa are summarized in Table 37. Use of sulfentrazone may 

cause direct adverse effects to non-listed and listed species of terrestrial plants and listed species 

of aquatic vascular and non-vascular plants. Use of sulfentrazone may cause direct adverse 

effects on birds and estuarine on a chronic basis. Because birds are surrogates for terrestrial 

phase reptiles and amphibians, risk is presumed to these taxa as well on a chronic basis. 

Sulfentrazone may also cause direct effects to estuarine/marine invertebrates on a chronic basis. 

It is not expected to cause direct effects to other listed species of terrestrial or aquatic animals 

such as mammals and fish, but toxicity to plants may result in indirect ecological effect to listed 

animals. Use of sulfentrazone does not cause direct adverse effects to non-listed and listed fish 

species as a result of the 29X correction factor used in the absence of studies conducted under 

ultraviolet light. 

Table 37. Potential Non-listed and Listed Species Risks Associated with Potential Direct or 

Indirect Effects Due to the Applications of Sulfentrazone 

Taxa 

DIRECT EFFECTS INDIRECT 

EFFECTS1 

Non-listed Listed 

Terrestrial and semi-aquatic plants 

– monocots Yes Yes Yes 

Terrestrial and semi-aquatic plants 

– dicots Yes Yes Yes 

Birds5 Yes Yes Yes 
78 

Taxa 

DIRECT EFFECTS INDIRECT 

EFFECTS1 

Non-listed Listed 

Terrestrial-phase amphibians6 Yes Yes Yes 

Reptiles6 Yes Yes Yes 

Mammals No No Yes 

Terrestrial Invertebrates No No Yes 

Aquatic plants – vascular plants No Yes Yes 

Aquatic plants – non-vascular No Yes2 Yes 

Freshwater fish No4 No4 Yes 

Aquatic-phase amphibians7 No No Yes 

Freshwater crustaceans No No Yes 

Mollusks No No Yes 

Marine/estuarine fish3 No4 No4 Yes 

Marine/estuarine crustaceans3 Yes4 Yes4 Yes 

1 Indirect effects may include general habitat modification, host plant loss, and food supply disruption. 2 No species of nonvascular aquatic plant is currently listed as threatened or endangered. 3 Quantitative data are not available for chronic toxicity in saltwater invertebrates; Risk conclusions were based on risk quotients 

calculated using the ACR for freshwater invertebrates. 

4Based on the daphnid ACR of 300 

4Risk was determined after applying the 29X factor for fish that is used in the absence of data from experiments conducted under

ultra-violet light per EFEDs LDPH guidance. 5Risk is based on chronic risk when birds feed upon diets containing sulfentrazone. These diet groups include short grass, tall

grass, broad leaf plants and arthropods. The category of fruit/pods/seeds did not result in any chronic risk to birds. 6 Birds are surrogates for reptiles and terrestrial-phase amphibians. Chronic risk associated with birds are thus inferred for these 

groups as well. 

7Fish are surrogates for aquatic-phase amphibians. 
79 

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Matringe, M., Camadro, J.M, Labbe, P., Scalla, R. 1989. Protoporphyrinogen oxidase as a 

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Mayer, D. and C. Johansen. 1990. Pollinator Protection: A Bee and Pesticide Handbook. 

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http://www.epa.gov/espp/consultation/ecorisk-overview.pdf 

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United States Environmental Protection Agency. Environmental Fate and Effects Division. 

http://www.epa.gov/oppefed1/models/terrestrial/index.htm#trex 

USEPA, 2008. EFED Problem Formulation for Sulfentrazone Registration Review. 

Memorandum from the Environmental Fate and Effects Division to the Registration 

Division, Office of Pesticide Programs, Office of Chemical Safety and Pollution 

Prevention. D36522, September, 2009. 

U.S. EPA, 2009. Guidance for Selecting Input Parameters in Modeling the Environmental Fate 

and Transport of Pesticides. October 22, 2009. U.S. Environmental Protection Agency, 

Office of Pesticide Programs, Environmental Fate and Effects Division. Arlington, VA 

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

U.S. EPA, 2010. Interim Guidance on Light-Dependant Peroxidizing Herbicides: Identification, 

DCI Justification, and Use of a Toxicity Adjustment Factor on Fish Chronic Endpoints. 

Memorandum from Donald Brady to the Environmental Fate and Effects Division. 

August 20, 2010. 

U.S. EPA, 2012. Baris, R., Barrett, M., Bohaty, R.F.H., Echeverria, M, Villanueva, P., Wolf, J., 

and Young, D. 2012. Guidance for Using PRZM-GW in Drinking Water Exposure 

Assessment. October 15, 2012. U.S. Environmental Protection Agency, Office of 

Pesticide Programs, Environmental Fate and Effects Division. Arlington, VA. 

http://www.epa.gov/oppefed1/models/water/przm_gw/wqtt_przm_gw_guidance.htm 

U.S. EPA, 2012. Marietta Echeverria, M., Jones, R.D., Peck, C., Ruhman, M., Shelby, A., 

Thawley, S., and Thurman, N. Development and Use of Percent Cropped Area and 

Percent Turf Area Adjustment Factors in Drinking Water Exposure Assessments: 2012 
80 

Update. March 16, 2012. U.S. Environmental Protection Agency, Office of Pesticide 

Programs, Environmental Fate and Effects Division. Arlington, VA 

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

U.S. EPA, 2012. OPP EFED. White Paper in Support of the Proposed Risk Assessment Process 

for Bees. 
81 

VIII. Appendices 

A. Bibliography 

1. Toxicity Studies 

a) Avian Single Dose Oral Toxicity 

MRID (i) Citation Reference

 41911617 Campbell, S.; Lynn, S.; Smith, G. (1991) F6285: An Acute Oral Toxicity Study with the Northern Bobwhite: Lab Project Number: A89- 

3089: 104-165. Unpublished study prepared by Wildlife International 

Ltd. 20 p. 

b) Avian Dietary Toxicity 

MRID Citation Reference 

 41911618 Beavers, J.; Grimes, J.; Smith, G.; et al. (1991) F6285: A Dietary LC50 

Study with the Northern Bobwhite: Lab Project Number: A89- 3091: 

104-163. Unpublished study prepared by Wildlife Inter- national Ltd. 36 

p. 

41911619 Beavers, J.; Grimes, J.; Smith, G. (1991) F6285: A Dietary LC50 Study 

with the Mallard: Lab Project Number: 104-164: A89-3092. Unpublished 

study prepared by Wildlife International Ltd. 36 p. 

c) Avian Reproduction 

MRID Citation Reference 

 43355901 Pedersen, C.; DuCharme, D. (1994) Toxicity and Reproduction Study 

with F6285 Technical in Bobwhite Quail: Lab Project Number: 112-005-

07: A93-3820. Unpublished study prepared by Bio-Life Associates, Ltd. 

457 p. 

43355902 Pedersen, C.; Solatycki, A. (1994) Toxicity and Reproduction Study with 

F6285 Technical in Mallard Ducks: Lab Project Number: 112-006-08: 

A93-3819. Unpublished study prepared by Bio-Life Associates, Ltd. 461 

p. 

d) Acute Toxicity to Freshwater Fish 

MRID Citation Reference 

 41911620 Graves, W. ; Peters, G. (1991) F6285: A 96-Hour Flow-through Acute 

Toxicity Test with the Rainbow Trout (Oncorhynchus mykiss): Final 
82 

Report: Lab Project Number: 104A-103: A89-3060. Unpub- lished study 

prepared by Wildlife International Ltd. 45 p. 

41911621 Graves, W.; Peters, G. (1991) F6285: A 96-Hour Flow-through Acute 

Toxicity Test with the Bluegill (Lepomis macrochirus): Final Report: 

Lab Project Number: 104A-104: A89-3061. Unpublished study prepared 

by Wildlife International Ltd. 47 p. 
83 

e) Acute Toxicity to Freshwater Invertebrates 

MRID Citation Reference 

 41911622 Holmes, C.; Peters, G. (1991) F6285: A 48-Hour Flow-through Acute 

Toxicity Test with the Cladoceran (Daphnia magna): Lab Project 

Number: 104A-105A: A89-3059. Unpublished study prepared by Wild 

life International Ltd. 46 p. 

f) Acute Toxicity to Estuarine/Marine Organisms 

MRID Citation Reference 

 43588602 Boeri, R.; Magazu, J.; Ward, T. (1994) F6285 Technical: Acute Toxicity 

to the Silverside, Menidia beryllina: Lab Project Number: A94-3973: 

495-FM. Unpublished study prepared by T. R. Wilbury Labs, Inc. 27 p. 

43588603 Boeri, R.; Magazu, J.; Ward, T. (1994) F6285 Technical: Acute Toxicity 

to the Mysid, Mysidopsis bahia: Lab Project Number: A94-3972: 494-

FM. Unpublished study prepared by T. R. Wilbury Labs, Inc. 27 p. 

44054901 Cunningham, F. (1996) Sulfentrazone Technical: Acute Effect on New 

Shell Growth of the Eastern Oyster (Crassostrea virginica): Lab Project 

Number: A96-4347: J9601008: F211. Unpublished study prepared by 

Toxikon Environmental Sciences. 43 p. 

g) Fish Early Life Stage/Aquatic Invertebrate Life Cycle Study 

MRID Citation Reference 

 43588604 Boeri, R.; Magazu, J.; Ward, T. (1994) Early Life-stage Toxicity of 

F6285 Technical to the Rainbow Trout, Oncorhynchus mykiss: Lab 

Project Number: A93-3804: 308-FM. Unpublished study prepared by T. 

R. Wilbury Labs, Inc. 78 p. 

43588605 Boeri, R.; Kowalski, P.; Ward, T. (1994) Chronic Toxicity of F6285 

Technical to the Daphnid, Daphnia magna: Lab Project Number: A93-

3803: 309-FM. Unpublished study prepared by T. R. Wilbury Labs, Inc. 

38 p. 

h) Acute oral toxicity in rats 

MRID Citation Reference 

 41911605 McCarty, J. (1988) F6285 Technical: Acute Oral Toxicity Study in Rats: 

Lab Project Number: A88-2587. Unpublished study prepared by FMC 

Tox Lab. 35 p. 

41911606 McCarty, J. (1988) F6285 Technical: Acute Oral Toxicity Study in Mice: 

Lab Project Number: A88-2598. Unpublished study prepared by FMC 

Tox Lab. 50 p. 

41911612 Freeman, C. (1991) F6285--4 Lb. /GAl F: Acute Oral Toxicity Study in 

Rats: Lab Project Number: A91-3384. Unpublished study pre- pared by 

FMC Corp. 22 p. 
84 

42051302 Freeman, C. (1991) Acute Oral Toxicity Study in Rats: F6285 80 WP: 

Lab Project Number: A91-3462. Unpublished study prepared by FMC 

Corp. 27 p. 

43233403 Freeman, C. (1994) F6285 75 DF: Acute Oral Toxicity Study in Rats: 

Lab Project Number: A93-3884. Unpublished study prepared by FMC 

Corp. 36 p. 

43926704 Freeman, C. (1996) Sulfentrazone/Metribuzin Blend 75 DF: Acute Oral 

Toxicity Study in Rats: Lab Project Number: A95-4274: ATM-0248: 

P95-0111. Unpublished study prepared by FMC Corp. 114 p. 

44116905 Finlay, C. (1996) Acute Oral Toxicity Study with DPX-MP559 in Male 

and Female Rats: Lab Project Number: HLR 570-96: 10718-001: 570-96. 

Unpublished study prepared by DuPont Haskell Lab for Toxicology and 

Industrial Medicine. 45 p. 

44463601 Wnorowski, G. (1997) Acute Oral Toxicity Defined LD 50 (in Rats): 

EH-1349: Lab Project Number: 5491: P320. Unpublished study prepared 

by Product Safety Labs. 30 p. 

45388202 Freeman, C.; Scubelek, S. (2001) Gauntlet 70 DF Acute Oral Toxicity 

Study in Rats: Lab Project Number: A2000-5316. Unpublished study 

prepared by FMC Corporation. 22 p. {OPPTS 870.1100} 

i) Seed Germination/Seedling Emergence and Vegetative Vigor 

MRID Citation Reference 

 43345411 Chetram, R. (1994) Tier 2 Seed Germination/Seedling Emergence 

Nontarget Phytotoxicity Study Using F6285 Technical: Lab Project 

Number: 162E7191E1: PC/0174: BL91/473. Unpublished study prepared 

by Pan-Agricultural Lab., Inc. 101 p. 

43345412 Chetram, R. (1994) Tier 2 Vegetative Vigor Nontarget Phytotoxicity 

Study Using F6285 Technical: Lab Project Number: BL91/474: 

162E7291E1: PC/0175. Unpublished study prepared by Pan-Agricultural 

Lab., Inc. 118 p. 

43783601 Keifer, D. (1995) Supplemental Data Submission in Support of: Tier 2 

Seed Germination/Seedling Emergence Nontarget Phytotoxicity Study 

Using F6285 Technical: Lab Project Number: BL91-473: 162E7191E1: 

PC-0174. Unpublished study prepared by FMC Corp. 92 p. 

43783602 Keifer, D. (1995) Supplemental Data Submission in Support of: Tier 2 

Vegetative Vigor Nontarget Phytotoxicity Study Using F6285 Technical: 

Lab Project Number: BL91-474: 162E7291E1: PC-0175. Unpublished 

study prepared by FMC Corp. 114 p. 

j) Aquatic Plant Growth 

MRID Citation Reference 

 43345413 Blasberg, J.; Hicks, S.; Stuerman, L. (1994) Acute Toxicity of F6285 to 

Selenastrum capricornutum Printz: Amended Final Report: Lab Project 
85 

Number: 40574: A92/3537. Unpublished study prepared by ABC Lab., 

Inc. 228 p. 

43651004 Ward, T.; Kowalski, P.; Boeri, R. (1995) Acute Toxicity of Sulfentrazone 

Technical to the Freshwater Alga, Navicula pelliculosa: Lab Project 

Number: A94-4106: 618-FM: P-2912. Unpublished study prepared by T. 

R. Wilbury Labs, Inc. 26 p. 

43651005 Ward, T.; Kowalski, P.; Boeri, R. (1995) Toxicity of Sulfentrazone 

Technical to the Duckweed, Lemna gibba G3: Amended Report: Lab 

Project Number: A94-4107: 620-FM. Unpublished study prepared by T. 

R. Wilbury Labs, Inc. 28 p. 

43651006 Ward, T.; Kowalski, P.; Boeri, R. (1995) Acute Toxicity of Sulfentrazone 

Technical to the Freshwater Alga, Anabaena flos-aquae: Lab Project 

Number: A94-4108: 617-FM. Unpublished study prepared by T. R. 

Wilbury Labs, Inc. 27 p. 

43651007 Ward, T.; Kowalski, P.; Boeri, R. (1995) Acute Toxicity of Sulfentrazone 

Technical to the Marine Alga, Skeletonema costatum: Lab Project 

Number: A94-4109: 619-FM. Unpublished study prepared by T. R. 

Wilbury Labs, Inc. 26 p. 

k) Honey Bee Acute Contact 

MRID Citation Reference 

 44054902 Aufderheide, J.; Kranzfelder, J. (1996) Sulfentrazone Technical: Honey 

Bee Acute Contact LD50: Lab Project Number: A95-4228: J9507010: 

F616. Unpublished study prepared by Toxikon Environmental Sciences. 

31 p. 

2. Environmental Fate Studies 

a) Hydrolysis 

MRID Citation Reference 

 41928202 Kabler, K.; Williamson, K. (1991) Hydrolysis as a Function of pH at 25 

C of 14C-F6285: Lab Project Number: 38404: PC-0151. Unpubli- shed 

study prepared by Analytical Bio-Chemistry Laboratories, Inc. 141 p. 

b) Photodegradation-water 

MRID Citation Reference 

 43345424 Schocken, M. (1994) F6285: Aqueous Photolysis Study Following 

FIFRA Guideline 161-2 and TSCA Guideline 796.3700 (for Quantum 

Yield Determination): Final Report: Lab Project Number: 282/1192/ 

6113/720: 93/7/4849: PC/0191. Unpublished study prepared by 

Springborn Lab., Inc. 228 p. 
86 

43588601 Willut, J. (1995) Formation and Decline of Major (carbon 14) 

Sulfentrazone Photoproducts in Buffered Aqueous Solution by Simulated 

Sunlight: Lab Project Number: 162E1294E1: P-2992. Unpublished study 

prepared by FMC Corp. 138 p. 

c) Photodegradation-soil 

MRID Citation Reference 

 43345425 Schocken, M. (1994) F6285: Soil Photolysis Study Following FIFRA 

Guideline 161-3: Final Report: Lab Project Number: 282/1192/6114/721: 

94/3/5186: PC/0208. Unpublished study prepared by Springborn Lab., 

Inc. 117 p. 

d) Aerobic soil metabolism 

MRID Citation Reference 

 41928203 Singer, S.; Schocken, M. (1989) Degradation Studies: Aerobic Soil 

Metabolism of F6285, a New Herbicide: Lab Project Number: 162E2- 

1RF1. Unpublished study prepared by FMC Corporation. 67 p. 

42932117 Curry, S. (1993) Aerobic Soil Metabolism of F6285: Lab Project 

Number: 162E2191E1. Unpublished study prepared by FMC Corp. 124 

p. 

e) Anaerobic aquatic metabolism 

MRID Citation Reference 

 43345426 Blumhorst, M. (1994) Anaerobic Aquatic Metabolism of F6285: Lab 

Project Number: 141/002: PC/0192: 162E2291E1. Unpublished study 

prepared by EPL Bio-Analytical Services, Inc. 221 p. 

f) Leach/adsorp/desorption 

MRID Citation Reference 

 41911604 Dykes, J. (1990) Soil Adsorption/Desorption with ?Carbon 14 F6285|: 

Final Report: Lab Project Number: 383611: FMC 162E3289E1: FMC 

Report PC-0138. Unpublished study prepared by ABC Labs, Inc. 129 p. 

43355903 Saxena, A.; Marengo, J.; Zwick, T. (1993) The Leaching Potential of 

(carbon 14)-F6285 and Degradates in a Sandy Loam Soil: Amended 

Final Report: Lab Project Number: SC910200: PC-0178: 162E3191E1. 

Unpublished study prepared by Battelle Memorial Institute. 113 p. 

g) Terrestrial field dissipation 

MRID Citation Reference 

 43345427 Culligan, J. (1994) F6285 4F Herbicide: Terrestrial Field Dissipation: 

Lab Project Number: P/2906: 162E4192E1. Unpublished study prepared 

by FMC Corp. 94 p. 
87 

43345434 Becker, J. (1994) A Combined Soil Dissipation and Small-Scale 

Prospective Groundwater Monitoring Study with F6285 4F Herbicide: 

Lab Project Number: P/2891: 162E6692E1. Unpublished study prepared 

by FMC Corp. 446 p. 

43651008 Nagel, W.; Culligan, J. (1995) Terrestrial Field Dissipation- -F6285 

75DF Herbicide: Lab Project Number: P-2995: 162E4193E1. 

Unpublished study prepared by FMC Corp. 84 p. 

43651009 Culligan, J. (1995) Terrestrial Field Dissipation--F6285 75DF Herbicide: 

Lab Project Number: P-2983: 162E4193E2. Unpublished study prepared 

by FMC Corp. 96 p. 

43926814 Becker, J. (1996) A Combined Soil Dissipation and Small-Scale 

Prospective Groundwater Monitoring Study with F6285 4F Herbicide: 

(Revised Report): Lab Project Number: 162E6692E1: P-2891: 

FMC9201. Unpublished study prepared by FMC Corp. 477 p. 

h) Bioaccumulation in fish 

MRID Citation Reference 

 43345433 Dionne, E. (1993) F6285: Bioconcentration and Elimination of (Carbon 

14) Residues by Bluegill Sunfish (Lepomis macrochirus): Final Report: 

Lab Project Number: 282/1091/6112/140: 92/7/4315: PC/0186. 

Unpublished study prepared by Springborn Lab., Inc. 122 p. 

Ground water-small prospective 

MRID Citation Reference 

 43926814 Becker, J. (1996) A Combined Soil Dissipation and Small-Scale 

Prospective Groundwater Monitoring Study with F6285 4F Herbicide: 

(Revised Report): Lab Project Number: 162E6692E1: P-2891: 

FMC9201. Unpublished study prepared by FMC Corp. 477 p. 

44773301 Hiscock, A.; Braun, D.; Culligan, J. (1999) A Small-Scale Prospective 

Groundwater Monitoring Study for Sulfentrazone in a Setting Classified 

as 85th Percentile Based on Vulnerability to Groundwater 

Contamination: Progress Report 1: Lab Project Number: PC-0291-1: 

162E6698E2: 98-050. Unpublished study prepared by Centre Analytical 

Laboratories, Inc. and Research Options, Inc. 332 p. 

44837201 Hiscock, A.; Braun, D.; Culligan, J. (1999) A Small-Scale Prospective 

Groundwater Monitoring Study for Sulfentrazone in a Setting Classified 

as 85th Percentile Based on Vulnerability to Groundwater 

Contamination: Progress Report 2: Lab Project Number: 97-154: 98-050: 

162E6698E2. Unpublished study prepared by Stone Environmental, Inc. 

and Research Options, Inc. 148 p. 

44845801 Chen, A.; Schellinger, G. (1999) A Small-Scale Prospective 

Groundwater Monitoring Study for Sulfentrazone in a Setting Classified 

as 95th Percentile Based on Vulnerability to Groundwater 
88 

Contamination: Lab Project Number: SEI97-155: 162E6699E1: PC0293. Unpublished study prepared by Stone Environmental, Inc. and 

Agvise Labs. 126 p. 

44978601 Schellinger, G.; Chen, A. (1999) A Small-Scale Prospective 

Groundwater Monitoring Study for Sulfentrazone in a Setting Classified 

as 95th Percentile Based on Vulnerability to Groundwater 

Contamination: Progress Report 1: Lab Project Number: 97-155: 99-024: 

162E6699E1. Unpublished study prepared by Stone Environmental, Inc. 

and Research Options, Inc. 225 p. 

44978701 Hiscock, A.; Collins, M.; Culligan, J. (1999) A Small-Scale Prospective 

Groundwater Monitoring Study for Sulfentrazone in a Setting Classified 

as 85th Percentile Based on Vulnerability to Groundwater 

Contamination: Progress Report #3: Lab Project Number: 97-154: 98-

050: 162E6698E2. Unpublished study prepared by Stone Environmental, 

Inc. and Research Options, Inc. 196 p. 

45075801 Schellinger, G.; Chen, A. (2000) A Small-Scale Prospective 

Groundwater Monitoring Study for Sulfentrazone in a Setting Classified 

as 95th Percentile Based on Vulnerability to Groundwater 

Contamination: Progress Report 2: Lab Project Number: 162E6699E1: 

PC-0293-2: 97-155. Unpublished study prepared by Stone 

Environmental, Inc. and Research Options, Inc. 133 p. 

45179201 Hiscock, A.; Patterson, B.; Culligan, J. (2000) A Small-Scale Prospective 

Groundwater Monitoring Study for Sulfentrazone in a Setting Classified 

as 85th Percentile Based in Vulnerability to Groundwater Contamination: 

Lab Project Number: 162E6698E2: PC-0291-4. Unpublished study 

prepared by Stone Environmental, Inc. and FMC Corporation. 320 p. 

45280401 Schellinger, G.; Chen, A. (2000) A Small-Scale Prospective 

Groundwater Monitoring Study for Sulfentrazone in a Setting Classifies 

as 95th Percentile Based on Vulnerability to Groundwater 

Contamination: Study Site Monitoring Through 294 Days After 

Treatment (Analytical Results through 276 Days After Treatment): 

Progress Report 3: Lab Project Number: 162E6699E1: PC-0293-3: 97-

155. Unpublished study prepared by Stone Environmental, Inc., Research 

Options, Inc. and FMC Corp. 225 p. 

45363701 Hiscock, A.; Patterson, B.; Culligan, J. (2001) A Small Scale Prospective 

Groundwater Monitoring Study for Sulfentrazone in a Setting Classified 

as 85 Percentile Based on Vulnerability to Groundwater Contamination: 

Progress Report 5: Sample Collection Through 774 Days After the First 

Treatment and Most Current Analytical Data: Lab Project Number: 

162E6698E2: PC-0291-5: 97-154. Unpublished study prepared by Stone 

Environmental, Inc., Centre Analytical Labs., Inc. and Research Options, 

Inc. 320 p. 

45377201 Schellinger, G.; Morris, R. (2001) A Small-Scale Prospective 

Groundwater Monitoring Study for Sulfentrazone in a Setting Classified 

as 75th Percentile Based on Vulnerability to Groundwater 

Contamination: Progress Report 1: Lab Project Number: PC-0303-1: 98-
89 

153: 00-006. Unpublished study prepared by Stone Environmental, Inc., 

Research Options, Inc. and Agvise Labs. 280 p. 

45430901 Schellinger, G.; Chen, A. (2001) A Small-Scale Prospective 

Groundwater Monitoring Study for Sulfentrazone in a Setting Classified 

as 95th Percentile Based on Vulnerability to Groundwater 

Contamination: Lab Project Number: 162E6699E1: PC-0293-4: 97-155. 

Unpublished study prepared by Stone Environmental, Inc. and Research 

Options, Inc. 251 p. 

45533901 Schellinger, G.; Morris, R. (2001) A Small-Scale Prospective 

Grounwater Monitoring Study for Sulfentrazone in a Setting Classified 

as 75th Percentile Based on Vulnerability to Groundwater 

Contamination: Progress Report 2: Lab Project Number: 98-153: 00-006: 

162E6600E1. Unpublished study prepared by Stone Environmental, Inc. 

187 p. 

45534001 Hiscock, A.; Patterson, B.; Culligan, J. (2001) A Small-Scale Prospective 

Groundwater Monitoring Study for Sulfentrazone in a Setting Classified 

as 85th Percentile Based on Vulnerability to Groundwater 

Contamination: Progress Report 6: Lab Project Number: 162E6698E2: 

98-050: 97-154. Unpublished study prepared by Stone Environmental, 

Inc. 302 p. 

45591401 Schellinger, G.; Chen, A. (2001) A Small-Scale Prospective 

Groundwater Monitoring Study for Sulfentrazone in a Setting Classified 

as 95th Percentile Based on Vulnerability to Groundwater 

Contamination: Progress Report 5: Lab Project Number: 162E6699E1: 

PC-0293-5: 97-155. Unpublished study prepared by Stone 

Environmental, Inc.; Research Options, Inc. and FMC Corporation. 215 

p. 

46085201 Hiscock, A.; Patterson, B.; Culligan, J. (2003) A Small-Scale Prospective 

Groundwater Monitoring Study for Sulfentrazone in a Setting Classified 

as 85th Percentile Based on Vulnerability to Groundwater 

Contamination: Progress Report 7. Project Number: PC/0291/7, 

162E6698E2. Unpublished study prepared by: Stone Environmental, Inc. 

and Research Options, Inc. and Exygen Research. 353 p. 

46353701 Hiscock, A.; Patterson, B.; Culligan, J. (2004) A Small Scale Prospective 

Groundwater Monitoring Study for Sulfentrazone in a Setting Classified 

as 85th Percentile Based on Vulnerability to Groundwater 

Contamination: Progress Report 8. Project Number: PC/0291/8, 

162E6698E2. Unpublished study prepared by FMC Corp. and Stone 

Environmental, Inc. and Research Options, Inc. 485 p. 

44732701 Dow, K. (1999) Analytical Services Biannual Report of Water Analysis 

for Sulfentrazone and Sulfentrazone-3-Carboxylic Acid: Revised Report: 

Lab Project Number: P-3343. Unpublished study prepared by Montana 

State University. 47 p. 

46816001 Chen, A. and Hanzas, J. (2006) A Small-Scale Prospective Groundwater 

Monitoring Study for Sulfentrazone in a Setting Classified as 95th 
90 

Percentile Based on Vulnerability to Groundwater Contamination. Final 

Report 5: Lab Project Number: 162E6699E1: PC-0293. Unpublished 

study prepared by Alliance Technologies and Stone Environmental, Inc. 

804 p. 

47453601 Culligan, J., Hanzas, J. and Patterson, B. (2008) A Small Scale 

Prospective Groundwater Monitoring Study for Sulfentrazone in a 

Setting Classified as 85th Percentile Based on Vulnerability to 

Groundwater Contamination. Project Number: 97/154, 98/050, 014/007. 

Unpublished study prepared by MPI Research, FMC Corp. and Stone 

Environmental, Inc. 1168 p. 

47453602 Morris, R. and Hanzas, J. (2008) A Small-Scale Prospective Grounwater 

Monitoring Study for Sulfentrazone in a Setting Classified as 75th 

Percentile Based on Vulnerability to Groundwater Contamination. 

Project Number: 98/153: 00/006: 162E6600E1. Unpublished study 

prepared by Stone Environmental, Inc. Research Options, Inc. and FMC 

Corp., Agricultural Products Group. 654 p. 
91 

B. Pesticide Products Registered in the United States that Contain 

Sulfentrazone 

Registration 

Number 

EPA Accepted 

Date AI % Formulation Type Product Density 

2217-823 4/16/2012 0.43 Soluble Concentrate 9.09lb/gal 

2217-866 6/21/2010 1.24 Soluble Concentrate 1.175gm/mL 

2217-867 12/6/2012 0.67 Soluble Concentrate 1.0915gm/mL 

2217-875 11/27/2012 0.18 Soluble Concentrate 1.035gm/mL 

2217-876 8/6/2009 0.008 Ready-to-Use Solution 1gm/mL 

2217-877 9/2/2008 0.007 Ready-to-Use Solution 1.0004gm/mL 

2217-879 1/14/2009 2.04 Formulation Intermediate 1.1508gm/mL 

2217-879 1/14/2009 2.04 Formulation Unidentified 1.1508gm/mL 

2217-880 2/27/2012 0.15 Soluble Concentrate 1.0284gm/mL 

2217-882 5/18/2010 0.034 Granular .74gm/mL 

2217-883 1/8/2010 0.034 Granular .74gm/mL 

2217-885 9/4/2008 0.42 Soluble Concentrate 1.0432gm/mL 

2217-886 8/24/2009 0.69 Soluble Concentrate 1.0705gm/mL 

2217-887 12/7/2012 0.015 Ready-to-Use Solution 1.0028gm/mL 

2217-888 11/27/2009 1.02 Soluble Concentrate 1.1043gm/mL 

2217-890 7/7/2010 0.025 Granular .575gm/mL 

2217-895 10/1/2009 2.04 Emulsifiable Concentrate 1.1508gm/mL 

2217-897 8/25/2009 0.034 Emulsifiable Concentrate .578gm/mL 

2217-914 1/5/2010 0.008 Ready-to-Use Solution 1.0028gm/mL 

2217-915 1/29/2010 0.18 Soluble Concentrate 1.0291gm/mL 

2217-917 10/2/2008 0.015 Ready-to-Use Solution 

2217-918 1/29/2010 0.22 Soluble Concentrate 1.0204gm/mL 

2217-920 10/2/2009 0.73 Emulsifiable Concentrate .989gm/cm^3 

2217-921 2/21/2013 0.63 Soluble Concentrate 1.1522gm/cm^3 

2217-930 12/6/2012 0.69 Emulsifiable Concentrate 1.0943gm/mL 
92 

Registration 

Number 

EPA Accepted 

Date AI % Formulation Type Product Density 

2217-944 2/4/2011 0.65 Emulsifiable Concentrate 1.1086gm/mL 

2217-946 1/21/2011 0.69 Emulsifiable Concentrate 1.08563gm/mL 

2217-947 3/5/2012 0.7 Emulsifiable Concentrate 1.0432gm/mL 

2217-948 6/13/2011 0.7 Emulsifiable Concentrate 1.0365gm/mL 

2217-967 6/8/2012 0.034 Granular .851gm/mL 

2217-968 6/8/2012 0.025 Granular .872gm/cm^3 

279-3146 6/5/1997 39.6 Emulsifiable Concentrate 10lb/gal 

279-3148 1/22/1998 75 Water Dispersible Granule 

279-3149 9/28/2012 91 Technical Chemical 31lb/ft^3 

279-3175 6/6/1997 47 Water Dispersible Granule 

279-3179 9/27/2001 46.9 Water Dispersible Granule 

279-3189 9/28/2012 75 Water Dispersible Granule 

279-3195 3/17/1998 75 Water Dispersible Granule 

279-3220 9/28/2012 39.6 Flowable Concentrate 10lb/gal 

279-3231 10/12/2000 37.5 Water Soluble Packaging 

279-3246 2/6/2013 62.1 Wettable Powder 38.1lb/ft^3 

279-3247 4/11/2002 62.1 Wettable Powder 

279-3282 11/19/2004 75 Water Dispersible Granule 41lb/ft^3 

279-3295 12/6/2012 39.6 Flowable Concentrate 10lb/gal 

279-3317 4/24/2009 0.1 Granular 1.5gm/mL 

279-3318 4/10/2009 0.3 Granular 1.5gm/mL 

279-3319 2/19/2010 0.3 Granular 96.7lb/ft^3 

279-3320 2/19/2010 0.19 Granular 96.7lb/ft^3 

279-3321 5/21/2009 0.17 Granular 96.7lb/ft^3 

279-3322 5/21/2009 0.1 Granular 96.7lb/ft^3 
93 

Registration 

Number 

EPA Accepted 

Date AI % Formulation Type Product Density 

279-3323 2/19/2010 13.6 Flowable Concentrate 9.95lb/gal 

279-3324 5/2/2011 21.5 Formulation Intermediate .26gm/mL 

279-3325 4/24/2009 0.053 Granular 96.7lb/ft^3 

279-3330 1/11/2011 33.33 Soluble Concentrate 10.1lb/gal 

279-3334 9/28/2012 5.7 Emulsifiable Concentrate 9.95lb/gal 

279-3337 9/28/2012 31.77 Emulsifiable Concentrate 9.99lb/gal 

279-3340 2/21/2013 18 Emulsifiable Concentrate 41.32lb/ft^3 

279-3350 11/30/2009 18 Water Dispersible Granule 41.32lb/ft^3 

279-3351 1/15/2009 33.33 Flowable Concentrate 10.1lb/gal 

279-3352 9/3/2008 5.7 Emulsifiable Concentrate 9.95lb/gal 

279-3353 1/27/2009 1.4 Ready-to-Use Solution 8.44lb/gal 

279-3354 11/15/2011 0.05 Ready-to-Use Solution 8.35lb/gal 

279-3355 5/18/2011 18.75 Water Dispersible Granule 35.4lb/ft^3 

279-3359 3/9/2012 3.5 Soluble Concentrate 9.97lb/gal 

279-3370 9/28/2012 39.6 Emulsifiable Concentrate 

279-3371 8/13/2010 0.1 Granular 

279-3378 10/9/2009 39.6 Emulsifiable Concentrate 10lb/gal 

279-3383 11/5/2009 31.77 Emulsifiable Concentrate 9.9lb/gal 

279-3407 12/15/2009 18.75 Water Dispersible Granule 

279-3408 10/4/2010 0.125 Granular 96.7lb/ft^3 

279-3411 3/29/2012 60 Water Dispersible Granule 38.3lb/ft^3 

279-3412 7/10/2012 18 Water Dispersible Granule 41.32lb/ft^3 

279-3413 3/4/2013 62.22 Water Dispersible Granule 36lb/ft^3 

279-3414 12/22/2011 16.74 Soluble Concentrate 9.85lb/gal 
94 

Registration 

Number 

EPA Accepted 

Date AI % Formulation Type Product Density 

279-3415 9/30/2010 21.46 Formulation Intermediate 15.5lb/ft^3 

279-3416 9/30/2010 0.386 Granular 55lb/ft^3 

279-3417 12/22/2011 0.129 Granular 55.3lb/ft^3 

279-3418 12/22/2011 0.385 Granular 55.3lb/ft^3 

279-3420 9/30/2010 0.129 Granular 55lb/ft^3 

279-3421 9/30/2010 0.129 Granular 

279-3422 9/30/2010 0.129 Granular 55.3lb/ft^3 

279-3423 9/30/2010 0.386 Granular 55lb/ft^3 

279-3424 9/30/2010 0.386 Granular 55.3lb/ft^3 

279-3427 6/10/2011 1.36 Flowable Concentrate 8.68lb/gal 

279-3437 11/8/2011 1.4 Ready-to-Use Solution 8.47lb/gal 

279-3438 11/30/2011 22 Emulsifiable Concentrate 9.11lb/gal 

279-3439 11/30/2011 22 Emulsifiable Concentrate 9.11lb/gal 

279-3442 2/26/2013 7.55 Soluble Concentrate 9.24lb/gal 

279-3452 11/20/2012 39.6 Flowable Concentrate 10lb/gal 

279-9536 6/3/2011 0.073 Granular 55.3lb/ft^3 

279-9537 6/3/2011 0.073 Granular 55.3lb/ft^3 

279-9539 6/3/2011 0.099 Granular 

279-9540 0.099 Granular 55.3lb/ft^3 

279-9560 6/14/2012 62.12 Granular 34.93lb/ft^3 

279-9561 6/14/2012 62.12 Granular 36.76lb/ft^3 

352-589 12/19/2003 46.9 Water Dispersible Granule 

352-590 5/21/2002 75 Water Dispersible Granule 

352-713 7/15/2010 75 Water Dispersible Granule 41lb/ft^3 

352-725 5/7/2009 48 Water Dispersible Granule .7gm/mL 

82534-5 12/21/2012 39.6 Emulsifiable Concentrate 10lb/gal 

88783-3 2/6/2013 94 Technical Chemical 1.32gm/mL 
95 

Registration 

Number 

EPA Accepted 

Date AI % Formulation Type Product Density 

9688-261 6/22/2011 0.008 Ready-to-Use Solution .996 

9688-268 6/17/2011 0.22 Soluble Concentrate 1.0226gm/mL 

9688-278 8/24/2010 0.18 Soluble Concentrate 1.0291gm/mL 

9688-279 8/24/2010 0.008 Ready-to-Use Solution 

9688-280 8/24/2010 0.015 Ready-to-Use Solution 1.0028gm/mL 

9688-281 8/24/2010 0.22 Soluble Concentrate 1.0204gm/mL 

AR070008 6/19/2007 39.6 Flowable Concentrate 10lb/gal 

AR080002 2/4/2008 39.6 Flowable Concentrate 10lb/gal 

AR090002 2/23/2009 18 Emulsifiable Concentrate 41.32lb/ft^3 

AR100001 3/2/2010 31.77 Emulsifiable Concentrate 9.99lb/gal 

AR130003 31.77 Emulsifiable Concentrate 9.99lb/gal 

DE100002 31.77 Emulsifiable Concentrate 9.99lb/gal 

IA110001 39.6 Flowable Concentrate 10lb/gal 

LA120014 39.6 Flowable Concentrate 10lb/gal 

LA120015 18 Emulsifiable Concentrate 41.32lb/ft^3 

MI110005 39.6 Flowable Concentrate 10lb/gal 

MN100003 5/11/2010 31.77 Emulsifiable Concentrate 9.99lb/gal 

MO050003 39.6 Flowable Concentrate 10lb/gal 

ND100001 4/6/2010 31.77 Emulsifiable Concentrate 9.99lb/gal 

ND130003 7.55 Soluble Concentrate 9.24lb/gal 

OH110007 39.6 Flowable Concentrate 10lb/gal 

OK080003 4/30/2008 39.6 Flowable Concentrate 10lb/gal 

OR110009 39.6 Flowable Concentrate 10lb/gal 

TN050002 39.6 Flowable Concentrate 10lb/gal 

TN070004 9/5/2007 39.6 Flowable Concentrate 10lb/gal 

TN080001 1/25/2008 39.6 Flowable Concentrate 10lb/gal 
96 

Registration 

Number 

EPA Accepted 

Date AI % Formulation Type Product Density 

TN090003 2/23/2009 18 Emulsifiable Concentrate 41.32lb/ft^3 

TN100001 4/5/2010 31.77 Emulsifiable Concentrate 9.99lb/gal 

TX120011 39.6 Flowable Concentrate 10lb/gal 

TX120012 18 Emulsifiable Concentrate 41.32lb/ft^3 

WA110007 39.6 Flowable Concentrate 10lb/gal 

WI110005 39.6 Flowable Concentrate 10lb/gal 

C. Chemical Names and Structures 

Table 38. Structures and properties of sulfentrazone and its degradates. 

Sulfentrazone (parent) 

Common Name: F6285 

IUPAC Name: 2′,4′-Dichloro-5′-(4-difluoromethyl-4,5-dihydro-3-methyl-5-oxo-1H1,2,4-triazol-1-yl)methanesulfonanilide 

CAS Name: N-[2,4-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H1,2,4-triazol-1-yl]phenyl]methanesulfonamide 

CAS #: 122836-35-5 

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

Molecular Formula: C11H10Cl2F2N4O3S 

Molecular Weight: 387.1 g/mol 

Synomyms: 
97 

Sulfentrazone 3-carboxylic acid (SCA) 

Common Name: FMC 129427 

IUPAC Name: 1-(2,4-Dichloro-5-(N-(methylsulfonyl)amino)-pheny]-4-difluoromethyl4,5-dihydro-5-oxo-1H-1,2,4-triazol-3-carboxylic acid 

CAS Name:: N-[2,4-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-5-oxo-1H-1,2,4-triazol1-yl]phenyl]methanesulfonamido-3-carboxylic acid 

CAS #: 134391-01-08 

Molecular Formula: C11H8Cl2F2N4O5S 

Molecular Weight: 417.18 g/mol 

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

Synonyms: 

IUPAC Name: 

CAS Name: 

CAS #: 

SMILES: 

Molecular Formula: 

Molecular Weight: 

Synonyms: 
98 

3-Hydroxymethyl-sulfentrazone (HMS) 

IUPAC: 1-(2,4-Dichloro-5-(N-(methylsulfonyl)amino)-pheny]-4-difluoromethyl-3-

hydroxy-methyl-1H-1,2,4-triazol-5(4H)-one 

CAS No.: 134390-99-1 

Formula: C11H10Cl2F2N4O4S

MW: 403.19 g/mol 

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

3-Desmethyl sulfentrazone (DMS) 

IUPAC: 1-(2,4-Dichloro-5-(N-(methylsulfonyl)amino)-pheny]-4-difluoromethyl-1H1,2,4-triazol-5(4H)-one 

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

yl]phenyl]methanesulfonamide

CAS No.: 134391-02-09 

Formula: C10H8Cl2F2N4O3S

MW: 373.17 g/mol 

SMILES: CS(=O)(=O)Nc1cc(c(cc1Cl)Cl)n2c(=O)n(cn2)C(F)F 
99 

Methyl triazole 

IUPAC: 4-Difluoromethyl-5-methyl-2,4-dihydro[1,2,4]triazole-3-one 

Formula: C4H5F2N3O

MW: 149.1 g/mol 

SMILES: Cc1n[nH]c(=O)n1C(F)F 
100 

D. ECOSAR Results for Property Prediction of Sulfentrazone and its 

Most Prominent Degradates 

ECOlogical Structure-Activity Relationship Model (ECOSAR) Results 

1. Parent Sulfentrazone 

ECOSAR Version 1.10 Results Page 

 

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

CHEM : Sulfentrazone 

CAS Num: 122836-35-5 

ChemID1: 

MOL FOR: C11 H10 CL2 F2 N4 O3 S1 

MOL WT : 387.19 

Log Kow: 2.647 (EPISuite Kowwin v1.68 Estimate) 

Log Kow: (User Entered) 

Log Kow: 0.99 (PhysProp DB exp value - for comparison only) 

Melt Pt: (User Entered for Wat Sol estimate) 

Melt Pt: 122.00 (deg C, PhysProp DB exp value for Wat Sol est) 

Wat Sol: 1669 (mg/L, EPISuite WSKowwin v1.43 Estimate) 

Wat Sol: (User Entered) 

Wat Sol: 780 (mg/L, PhysProp DB exp value) 

 

 

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

Values used to Generate ECOSAR Profile 

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

Log Kow: 2.647 (EPISuite Kowwin v1.68 Estimate) 

Wat Sol: 780 (mg/L, PhysProp DB exp value) 

 

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

Available Measured Data from ECOSAR Training Set 

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

 No Data Available 

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

ECOSAR v1.1 Class-specific Estimations 

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

Hydrazines 

Amides 

 Predicted 
101 

ECOSAR Class Organism Duration End Pt mg/L (ppm) 

=========================== ================== ======== ====== 

========== 

Hydrazines : Fish 96-hr LC50 2.181 

Hydrazines : Daphnid 48-hr LC50 8.406 

Hydrazines : Green Algae 96-hr EC50 0.621 

Hydrazines : Fish ChV 0.099 ! 

Hydrazines : Daphnid ChV 0.504 ! 

Hydrazines : Green Algae ChV 0.207 

Amides : Fish 96-hr LC50 39.862 

Amides : Daphnid 48-hr LC50 32.575 

Amides : Green Algae 96-hr EC50 1.441 

Amides : Fish ChV 0.100 

Amides : Daphnid ChV 2.801 

Amides : Green Algae ChV 1.779 

Amides : Fish (SW) 96-hr LC50 35.441 

Amides : Mysid (SW) 96-hr LC50 2.749 

=========================== ================== ======== ====== 

========== 

Neutral Organic SAR : Fish 96-hr LC50 83.455 

(Baseline Toxicity) : Daphnid 48-hr LC50 49.919 

 : Green Algae 96-hr EC50 46.471 

 : Fish ChV 8.753 

 : Daphnid ChV 5.793 

 : Green Algae ChV 14.350 

 Note: * = asterisk designates: Chemical may not be soluble enough to 

 measure this predicted effect. If the effect level exceeds the 

 water solubility by 10X, typically no effects at saturation (NES) 

 are reported. 

 

 NOTE: ! = exclamation designates: The toxicity value was estimated through 

 application of acute-to-chronic ratios per methods outlined in 

 the ECOSAR Methodology Document provided in the ECOSAR Help Menu. 

 

 

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

Class Specific LogKow Cut-Offs 

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

If the log Kow of the chemical is greater than the endpoint specific cut-offs 

presented below, then no effects at saturation are expected for those endpoints. 

 

Hydrazines: 

---------- 
102 

Maximum LogKow: 5.0 (LC50) 

Maximum LogKow: 6.4 (EC50) 

Maximum LogKow: 8.0 (ChV) 

 

Amides : 

------- 

Maximum LogKow: >8.5 (LC50) 

Maximum LogKow: >8.0 (EC50,ChV) 

 

Baseline Toxicity SAR Limitations: 

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

Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50) 

Maximum LogKow: 6.4 (Green Algae EC50) 

Maximum LogKow: 8.0 (ChV) 

2. Sulfentrazone 3-carboxylic acid (SCA) 

ECOSAR Version 1.10 Results Page 

 

SMILES : CS(=O)(=O)Nc1cc(c(cc1CL)CL)N2C(=O)N(C(=N2)C(=O)O)C(F)F 

CHEM : Sulfentrazone 3-carboxylic acid (SCA) 

CAS Num: 134391-01-08 

ChemID1: 

MOL FOR: C11 H8 CL2 F2 N4 O5 S1 

MOL WT : 417.17 

Log Kow: 1.410 (EPISuite Kowwin v1.68 Estimate) 

Log Kow: (User Entered) 

Log Kow: (PhysProp DB exp value - for comparison only) 

Melt Pt: (User Entered for Wat Sol estimate) 

Melt Pt: (deg C, PhysProp DB exp value for Wat Sol estimate) 

Wat Sol: 149.6 (mg/L, EPISuite WSKowwin v1.43 Estimate) 

Wat Sol: (User Entered) 

Wat Sol: (PhysProp DB exp value) 

 

 

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

Values used to Generate ECOSAR Profile 

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

Log Kow: 1.410 (EPISuite Kowwin v1.68 Estimate) 

Wat Sol: 149.6 (mg/L, EPISuite WSKowwin v1.43 Estimate) 

 

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

Available Measured Data from ECOSAR Training Set 

------------------------------------------------ 
103 

 No Data Available 

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

ECOSAR v1.1 Class-specific Estimations 

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

Hydrazines 

Amides 

 Predicted 

ECOSAR Class Organism Duration End Pt mg/L (ppm) 

=========================== ================== ======== ====== 

========== 

Hydrazines : Fish 96-hr LC50 6.522 

Hydrazines : Daphnid 48-hr LC50 34.000 

Hydrazines : Green Algae 96-hr EC50 1.646 

Hydrazines : Fish ChV 0.429 ! 

Hydrazines : Daphnid ChV 2.590 ! 

Hydrazines : Green Algae ChV 0.467 

Amides : Fish 96-hr LC50 329.141 * 

Amides : Daphnid 48-hr LC50 475.555 * 

Amides : Green Algae 96-hr EC50 9.114 

Amides : Fish ChV 0.397 

Amides : Daphnid ChV 18.072 

Amides : Green Algae ChV 6.675 

Amides : Fish (SW) 96-hr LC50 288.993 * 

Amides : Mysid (SW) 96-hr LC50 15.173 

=========================== ================== ======== ====== 

========== 

Neutral Organic SAR : Fish 96-hr LC50 1160.420 * 

(Baseline Toxicity) : Daphnid 48-hr LC50 548.928 * 

 : Green Algae 96-hr EC50 507.389 * 

 : Fish ChV 106.370 

 : Daphnid ChV 52.293 

 : Green Algae ChV 86.081 

 Note: * = asterisk designates: Chemical may not be soluble enough to 

 measure this predicted effect. If the effect level exceeds the 

 water solubility by 10X, typically no effects at saturation (NES) 

 are reported. 

 

 NOTE: ! = exclamation designates: The toxicity value was estimated through 

 application of acute-to-chronic ratios per methods outlined in 

 the ECOSAR Methodology Document provided in the ECOSAR Help Menu. 

 
104 

 

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

Class Specific LogKow Cut-Offs 

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

If the log Kow of the chemical is greater than the endpoint specific cut-offs 

presented below, then no effects at saturation are expected for those endpoints. 

 

Hydrazines: 

---------- 

Maximum LogKow: 5.0 (LC50) 

Maximum LogKow: 6.4 (EC50) 

Maximum LogKow: 8.0 (ChV) 

 

Amides : 

------- 

Maximum LogKow: >8.5 (LC50) 

Maximum LogKow: >8.0 (EC50,ChV) 

 

Baseline Toxicity SAR Limitations: 

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

Maximum LogKow: 5.0 (Fish 96-hr LC50; Daphnid LC50) 

Maximum LogKow: 6.4 (Green Algae EC50) 

Maximum LogKow: 8.0 (ChV) 
105 

E. Aquatic Exposure Model Input and Output 

1. List of Surface Water Standard Scenarios Used 

Scenario Crop

Abbreviation

Crop Agronomy

Simulated

App Apples

App Apples

App Apples

Asp Asparagus

Bea Beans

Cbb Cabbage

Cit Citrus

Cit Citrus

Cno Canola

Cor Corn

Cor Corn

Cor Corn

Cor Corn

Cor Corn

Cuc Cucumber

Fil Filberts

Gra Grapes

Gra Grapes

Gra Grass seed

Min Mint

Pcn Pecan

Pep Peppers

Pnt Peanut

Pot Potato

Pot Potato

Sgc Sugarcane

Sgc Sugarcane

Srg Sorghum

Str Strawbery

Syb Soybean

Tba Tobacco

Tma Tomato

Tma Tomato

Tma Tomato

Tur Turf

Tur Turf
106 

Wal

Almonds /

Walnuts

Whe Wheat

Xma Xmas Trees

2. Sample Model Input Files 

a) PE5 Input File for Tier 2.5 Modeling of Sulfentrazone Fate in 

Turbid Waters with a High Exposure Scenario (FL Peppers) 

Output File: FL-Pep_SlfnAer1pht98 

Metfile: w12844.dvf 

PRZM scenario: FLpeppersSTD.txt 

EXAMS environment file: pond298.exv 

Chemical Name: Sulfentrazone 

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 1105 days Halfife 

Anaerobic Aquatic Metabolism kbacs 0 days Halfife 

Aerobic Soil Metabolism asm 552.3 days Halfife 

Hydrolysis: pH 7 375 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 EPA Pond 

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

entire run) 

b) Sample PRZM Input File (FL Peppers Scenario, October 31 

Annual Sulfentrazone Applications, 98-day Photolysis t1/2 input) 

FL Bell Peppers (General Vegetable Scenario) 

"Collier and Hendry Counties; MLRA: 156A; Weather Station West Palm Beach 

Metfile: W12844.dvf," 

*** Record 3: 

 0.78 0 0 32.5 1 1 
107 

*** Record 6 -- ERFLAG 

 4 

*** Record 7: 

 0.03 0.2 1 10 4 1 356.8 

*** Record 8 

 1 

*** Record 9 

 1 0.15 45 40 3 88 87 91 0 30 

*** Record 9a-e 

 1 27 

0109 1609 0110 1610 0111 1611 0112 1612 0101 1601 0102 1602 0103 1603 0104 

1604 

.422 .547 .636 .683 .715 .743 .768 .793 .813 .830 .846 .859 .870 .878 .881 

.881 

.011 .011 .011 .011 .011 .011 .011 .011 .011 .011 .011 .011 .011 .011 .011 

.011 

 87 87 87 87 87 87 91 91 91 91 91 91 91 91 91 

91 

0105 1505 1605 2505 0106 1606 0107 1607 0108 1008 1608 

.880 .836 .849 .938 .840 .572 .285 .177 .162 .210 .291 

.011 .011 .011 .011 .011 .011 .011 .011 .011 .011 .011 

 91 91 91 91 91 91 91 91 91 91 91 

*** Record 10 -- NCPDS, the number of cropping periods 

 30 

*** Record 11 

 010961 151161 011261 1 

 010962 151162 011262 1 

 010963 151163 011263 1 

 010964 151164 011264 1 

 010965 151165 011265 1 

 010966 151166 011266 1 

 010967 151167 011267 1 

 010968 151168 011268 1 

 010969 151169 011269 1 

 010970 151170 011270 1 

 010971 151171 011271 1 

 010972 151172 011272 1 

 010973 151173 011273 1 

 010974 151174 011274 1 

 010975 151175 011275 1 

 010976 151176 011276 1 

 010977 151177 011277 1 

 010978 151178 011278 1 

 010979 151179 011279 1 

 010980 151180 011280 1 

 010981 151181 011281 1 

 010982 151182 011282 1 

 010983 151183 011283 1 

 010984 151184 011284 1 

 010985 151185 011285 1 

 010986 151186 011286 1 

 010987 151187 011287 1 

 010988 151188 011288 1 

 010989 151189 011289 1 

 010990 151190 011290 1 

*** Record 12 -- PTITLE 

Sulfentrazone - 1 applications @ 0.4203 kg/ha 
108 

*** Record 13 

 30 1 0 0 

*** Record 15 -- PSTNAM 

Sulfentrazone 

*** Record 16 

 311061 0 2 0.00.4203 .95 .05 

 311062 0 2 0.00.4203 .95 .05 

 311063 0 2 0.00.4203 .95 .05 

 311064 0 2 0.00.4203 .95 .05 

 311065 0 2 0.00.4203 .95 .05 

 311066 0 2 0.00.4203 .95 .05 

 311067 0 2 0.00.4203 .95 .05 

 311068 0 2 0.00.4203 .95 .05 

 311069 0 2 0.00.4203 .95 .05 

 311070 0 2 0.00.4203 .95 .05 

 311071 0 2 0.00.4203 .95 .05 

 311072 0 2 0.00.4203 .95 .05 

 311073 0 2 0.00.4203 .95 .05 

 311074 0 2 0.00.4203 .95 .05 

 311075 0 2 0.00.4203 .95 .05 

 311076 0 2 0.00.4203 .95 .05 

 311077 0 2 0.00.4203 .95 .05 

 311078 0 2 0.00.4203 .95 .05 

 311079 0 2 0.00.4203 .95 .05 

 311080 0 2 0.00.4203 .95 .05 

 311081 0 2 0.00.4203 .95 .05 

 311082 0 2 0.00.4203 .95 .05 

 311083 0 2 0.00.4203 .95 .05 

 311084 0 2 0.00.4203 .95 .05 

 311085 0 2 0.00.4203 .95 .05 

 311086 0 2 0.00.4203 .95 .05 

 311087 0 2 0.00.4203 .95 .05 

 311088 0 2 0.00.4203 .95 .05 

 311089 0 2 0.00.4203 .95 .05 

 311090 0 2 0.00.4203 .95 .05 

*** Record 17 

 0 1 0 

*** Record 18 

 0 0 0.5 

*** Record 19 -- STITLE 

Riviera Sand; HYDG: C 

*** Record 20 

 100 0 0 1 0 0 0 0 0 0 

*** Record 26 

 0 0 0 

*** Record 30 

 4 29 

*** Record 33 

 3 

 1 10 1.65 0.073 0 0 0 

 0.0012550.001255 0 

 0.1 0.073 0.023 1.16 0 

 2 62 1.65 0.073 0 0 0 

 0.0012550.001255 0 

 2 0.073 0.023 1.16 0 

 3 28 1.7 0.211 0 0 0 

 0.0012550.001255 0 
109 

 4 0.211 0.091 0.174 0 

***Record 40 

 0 

 YEAR 10 YEAR 10 YEAR 10 1 

 1 

 1 ----- 

 7 YEAR 

 PRCP TCUM 0 0 

 RUNF TCUM 0 0 

 INFL TCUM 1 1 

 ESLS TCUM 0 0 1.0E3 

 RFLX TCUM 0 0 1.0E5 

 EFLX TCUM 0 0 1.0E5 

 RZFX TCUM 0 0 1.0E5 

c) EXPRESS Project Input File for Modeling of Premergence 

Applications of Sulfentrazone 

Master Project File Created: 2014-02-17 at 17:50:13 

Express v. 1.03.02 (2007-07-20) 

Parent Compound: Sulfentrazone 

 Scenario Group File: 1 SLFNT14.GRP 

 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 | 

 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: 552.3 

 % 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 
110 

 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 

 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 
111 

 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 

 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 
112 

 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 

 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 
113 

 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: 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 
114 

 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 : 0.2500 

 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 
115 

 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 

 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 56.00 0 
116 

 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 0 

 Aerobic Dissipation (days) : 1105. 

 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): 0.5000 

 Number of Hydrolysis Obs.: 3 

 Hydrolysis Temperatures: 25.00 

 Hydrolysis C1: 1.430E+02 3.750E+02 3.480E+02 

 pH Hydrol. C1: 5.00 7.00 9.00 

 Melting Point: -99.00 

d) EXPRESS Project Input File for Modeling of Postemergent or 

Mid-Season Applications of Sulfentrazone 

Master Project File Created: 2014-02-17 at 19:13:35 

Express v. 1.03.02 (2007-07-20) 

Parent Compound: Sulfentrazone 

 Scenario Group File: 1 SLFNT14.GRP 

 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 | 

 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: 552.3 

 % 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 
117 

 Application DataSets Number: 39 

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

 Days Relative/Absolute : 40 

 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 : 40 

 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 : 40 

 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 : 40 

 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 : 40 

 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 : 40 

 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 : 40 
118 

 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 : 40 

 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 : 40 

 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 : 40 

 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 : 40 

 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 : 40 

 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 : 40 

 Month : 0 

 CAM : 2 

 Depi (cm) : 4.000 
119 

 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 : 40 

 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 : 40 

 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 : 40 

 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 : 40 

 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 : 40 

 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 : 40 

 Month : 0 

 CAM : 2 

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 
120 

 Efficiency % : 95.00 

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

 Days Relative/Absolute : 40 

 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 : 40 

 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 : 40 

 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 : 40 70 

 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 : 40 

 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 : 40 

 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 
121 

 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 : 40 

 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 : 40 

 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 : 40 

 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 : 40 

 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 : 40 

 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 : 40 

 Month : 0 

 CAM : 2 

 Depi (cm) : 4.000 
122 

 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 : 40 

 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 : 40 

 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 : 40 

 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 : 40 

 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 : 40 

 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 : 40 

 Month : 0 

 CAM : 2 

 Depi (cm) : 4.000 

 Rate : 0.3750 

 Drift Farm Pond % : 5.000 

 Drift Index Reservoir % : 16.00 
123 

 Efficiency % : 95.00 

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

 Days Relative/Absolute : 40 

 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 0 

 Aerobic Dissipation (days) : 1105. 

 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): 0.5000 

 Number of Hydrolysis Obs.: 3 

 Hydrolysis Temperatures: 25.00 

 Hydrolysis C1: 1.430E+02 3.750E+02 3.480E+02 

 pH Hydrol. C1: 5.00 7.00 9.00 

 Melting Point: -99.00 

3. Sample Model Output Files 

(PE5 PRZM-EXAMS Shell) 

Florida Peppers Scenario – October 11 Application Date, Slower Photolysis rate for Turbid 

Waters 

stored as FL-Pep_SlfnAer1pht98_11-10.out 

Chemical: Sulfentrazone 

PRZM environment: FLpeppersSTD.txt modified Thuday, 24 May 2007 at 09:44:22 

EXAMS environment: pond298.exv modified Thuday, 24 July 2003 at 09:02:00 

Metfile: w12844.dvf modified Wedday, 3 July 2002 at 08:04:30 

Water segment concentrations (ppb) 

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly 

1961 6.409 6.369 6.294 6.028 5.012 1.236 

1962 5.366 5.339 5.227 4.985 4.812 3.92 

1963 7.498 7.454 7.275 6.924 6.305 3.696 

1964 29.3 29.12 28.59 27.1 24.27 9.367 

1965 38.77 38.54 37.61 35.74 32.11 20.87 

1966 31.49 31.35 30.73 29.38 28.41 21.69 

1967 15.99 15.92 15.62 14.96 14.47 11.22 

1968 12.49 12.42 12.15 11.58 10.37 7.506 

1969 10.81 10.75 10.54 10.05 9.329 7.996 

1970 9.009 8.968 8.798 8.427 8.154 6.324 

1971 4.973 4.951 4.858 4.655 4.505 3.725 

1972 9.383 9.327 9.099 8.182 6.297 3.555 

1973 8.046 8.005 7.836 7.478 7.22 5.631 
124 

1974 5.62 5.588 5.464 5.208 4.763 3.742 

1975 4.638 4.615 4.521 4.316 4.168 3.412 

1976 12.02 11.95 11.72 11.28 10.16 4.344 

1977 9.928 9.881 9.689 9.27 8.959 6.882 

1978 5.481 5.457 5.355 5.134 4.971 4.084 

1979 5.828 5.794 5.66 5.397 4.916 3.463 

1980 4.775 4.753 4.659 4.459 4.313 3.586 

1981 4.602 4.578 4.478 4.266 3.96 3.013 

1982 6.137 6.102 5.963 5.662 4.76 3.368 

1983 5.215 5.19 5.086 4.861 4.699 3.829 

1984 4.275 4.252 4.162 4.018 3.611 2.921 

1985 4.417 4.4 4.306 4.094 3.733 2.973 

1986 4.985 4.964 4.847 4.597 4.171 3.057 

1987 20.72 20.59 20.06 19.05 16.9 6.429 

1988 16.64 16.55 16.22 15.49 14.97 11.63 

1989 15.75 15.66 15.47 14.91 13.69 8.817 

1990 13.18 13.11 12.84 12.25 11.82 9.133 

Sorted results 

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

0.032258064516129 38.77 38.54 37.61 35.74 32.11 21.69 

0.0645161290322581 31.49 31.35 30.73 29.38 28.41 20.87 

0.0967741935483871 29.3 29.12 28.59 27.1 24.27 11.63 

0.129032258064516 20.72 20.59 20.06 19.05 16.9 11.22 

0.161290322580645 16.64 16.55 16.22 15.49 14.97 9.367 

0.193548387096774 15.99 15.92 15.62 14.96 14.47 9.133 

0.225806451612903 15.75 15.66 15.47 14.91 13.69 8.817 

0.258064516129032 13.18 13.11 12.84 12.25 11.82 7.996 

0.290322580645161 12.49 12.42 12.15 11.58 10.37 7.506 

0.32258064516129 12.02 11.95 11.72 11.28 10.16 6.882 

0.354838709677419 10.81 10.75 10.54 10.05 9.329 6.429 

0.387096774193548 9.928 9.881 9.689 9.27 8.959 6.324 

0.419354838709677 9.383 9.327 9.099 8.427 8.154 5.631 

0.451612903225806 9.009 8.968 8.798 8.182 7.22 4.344 

0.483870967741936 8.046 8.005 7.836 7.478 6.305 4.084 

0.516129032258065 7.498 7.454 7.275 6.924 6.297 3.92 

0.548387096774194 6.409 6.369 6.294 6.028 5.012 3.829 

0.580645161290323 6.137 6.102 5.963 5.662 4.971 3.742 

0.612903225806452 5.828 5.794 5.66 5.397 4.916 3.725 

0.645161290322581 5.62 5.588 5.464 5.208 4.812 3.696 

0.67741935483871 5.481 5.457 5.355 5.134 4.763 3.586 

0.709677419354839 5.366 5.339 5.227 4.985 4.76 3.555 

0.741935483870968 5.215 5.19 5.086 4.861 4.699 3.463 

0.774193548387097 4.985 4.964 4.858 4.655 4.505 3.412 

0.806451612903226 4.973 4.951 4.847 4.597 4.313 3.368 

0.838709677419355 4.775 4.753 4.659 4.459 4.171 3.057 

0.870967741935484 4.638 4.615 4.521 4.316 4.168 3.013 

0.903225806451613 4.602 4.578 4.478 4.266 3.96 2.973 

0.935483870967742 4.417 4.4 4.306 4.094 3.733 2.921 

0.967741935483871 4.275 4.252 4.162 4.018 3.611 1.236 

0.1 28.442 28.267 27.737 26.295 23.533 11.589 

 Average of yearly averages: 6.38063333333333 

Inputs generated by pe5.pl - Novemeber 2006 

Data used for this run: 
125 

Output File: FL-Pep_SlfnAer1pht98_11-10 

Metfile: w12844.dvf 

PRZM scenario: FLpeppersSTD.txt 

EXAMS environment file: pond298.exv 

Chemical Name: Sulfentrazone 

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 1105 days Halfife 

Anaerobic Aquatic Metabolism kbacs 0 days Halfife 

Aerobic Soil Metabolism asm 552.3 days Halfife 

Hydrolysis: pH 7 375 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 EPA Pond 

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

entire run) 
126 

F. Terrestrial Exposure Model Results 

Output from T-Rex and TerrPlant Model Runs for Sulfentrazone 

1. T-Rex Run for Spray Applications 

Upper Bound Kenaga Residues For RQ Calculation 

Chemical Name: Sulfentrazone 

 Use 0 

 Formulation Sulfentrazone 4F ROW (4lbs ai per gallon suspension) 

Application Rate 0.375 lbs a.i./acre 

Half-life 35 days 

Application Interval 1 days 

Maximum # Apps./Year 1 

Length of Simulation 1 year 

Variable application rates? no 

 

Endpoints 

Avian 

Bobwhite 

quail 

LD50 (mg/kgbw) 2250.00 

Mallard duck) 

LC50 (mg/kgdiet) 0.00 

Bobwhite 

quail 

NOAEL(mg/kgbw) 0.00 

Bobwhite 

quail 

NOAEC 

(mg/kg-diet) 10.00 

 

Mammals 

LD50 (mg/kg-bw) 2855.00 

LC50 (mg/kg-diet) 0.00 

NOAEL (mg/kg-bw) 200.00 

NOAEC (mg/kg-diet) 4000.00 

 

Dietarybased 

EECs (ppm)

Kenaga 

Values 

Short Grass 31.88 

Tall Grass 13.50 
127 

Broadleaf plants 16.88 

Fruits/pods/seeds 2.63 

Arthropods 24.38 

 

Avian Results 

Avian Body 

Ingestion 

(Fdry) 

Ingestion 

(Fwet) % body wgt FI 

Class Weight (g) (g bw/day) (g/day) consumed (kg-diet/day) 

Small 20 5 23 114 2.28E-02 

Mid 100 13 65 65 6.49E-02 

Large 1000 58 291 29 2.91E-01 

 20 5 5 25 5.06E-03 

Granivores 100 13 14 14 1.44E-02 

 1000 58 65 6 6.46E-02 

Avian Body Adjusted LD50 

Weight (g) (mg/kg-bw) 

20 1620.97 

100 2063.57 

1000 2914.87 

Dose-based EECs (mg/kg-bw)

Avian Classes and Body Weights (grams) 

small mid large 

20 100 1000 

Short Grass 36.30 20.70 9.27 

Tall Grass 15.38 8.77 3.93 

Broadleaf plants 19.22 10.96 4.91 

Fruits/pods 2.99 1.70 0.76 

Arthropods 27.76 15.83 7.09 

Seeds 0.66 0.38 0.17 

Dose-based RQs 

(Dose-based EEC/adjusted LD50)

Avian Acute RQs 

Size Class (grams) 

20 100 1000 

Short Grass 0.02 0.01 0.00 

Tall Grass 0.01 0.00 0.00 

Broadleaf plants 0.01 0.01 0.00 

Fruits/pods 0.00 0.00 0.00 

Arthropods 0.02 0.01 0.00 

Seeds 0.00 0.00 0.00 

Dietary-based RQs 

(Dietary-based EEC/LC50 or 

NOAEC)

RQs 

 
128 

 Acute Chronic 

Short Grass #DIV/0! 3.19 

Tall Grass #DIV/0! 1.35 

Broadleaf plants #DIV/0! 1.69 

Fruits/pods/seeds #DIV/0! 0.26 

Arthropods #DIV/0! 2.44 

 
129 

Mammalian Results 

Mammalian Body 

Ingestion 

(Fdry) 

Ingestion 

(Fwet) % body wgt FI 

Class Weight (g bwt/day) (g/day) consumed (kg-diet/day) 

 15 3 14 95 1.43E-02 

Herbivores/ 35 5 23 66 2.31E-02 

insectivores 1000 31 153 15 1.53E-01 

 15 3 3 21 3.18E-03 

Grainvores 35 5 5 15 5.13E-03 

 1000 31 34 3 3.40E-02 

Mammalian Body Adjusted Adjusted 

Class Weight LD50 NOAEL 

 15 6274.81 439.57 

Herbivores/ 35 5076.99 355.66 

insectivores 1000 2195.95 153.83 

 15 6274.81 439.57 

Grainvores 35 5076.99 355.66 

 1000 2195.95 153.83 

Dose-Based 

EECs 

(mg/kg-bw)

Mammalian Classes and Body weight 

(grams) 

15 35 1000 

Short Grass 30.39 21.00 4.87 

Tall Grass 12.87 8.90 2.06 

Broadleaf plants 16.09 11.12 2.58 

Fruits/pods 2.50 1.73 0.40 

Arthropods 23.24 16.06 3.72 

Seeds 0.56 0.38 0.09 

Dosebased 

RQs 

(Dose-based 

EEC/LD50 or 

NOAEL)

Small mammal Medium mammal Large mammal 

15 grams 35 grams 1000 Grams 

Acute Chronic Acute Chronic Acute Chronic 

Short Grass 0.00 0.07 0.00 0.06 0.00 0.03 

Tall Grass 0.00 0.03 0.00 0.03 0.00 0.01 

Broadleaf plants 0.00 0.04 0.00 0.03 0.00 0.02 

Fruits/pods 0.00 0.01 0.00 0.00 0.00 0.00 

Arthropods 0.00 0.05 0.00 0.05 0.00 0.02 

Seeds 0.00 0.00 0.00 0.00 0.00 0.00 
130 

 
131 

Dietary-based 

RQs (Dietary-based 

EEC/LC50 or NOAEC)

Mammal RQs 

 

Acute Chronic 

Short Grass #DIV/0! 0.01 

Tall Grass #DIV/0! 0.00 

Broadleaf plants #DIV/0! 0.00 

Fruits/pods/seeds #DIV/0! 0.00 

Arthropods #DIV/0! 0.01 

T-Rex Run for (LD50/Sq. ft. Calculations) 

 
132 

Chemical: Sulfentrazone 

 

LD50 ft-2 

 

INPUTS Do not overwrite these numbers. Changes to the inputs must be 

Application Rate: 0.375 

lbs / 

acre made in the "INPUTS" worksheet. 

% A.I.: 100.00% 

Avian LD50 (20g): 1620.97 mg/kg bw 

(100g) 2063.57 

(1000g) 2914.87 

Mammalian LD50 (15g): 6274.81 mg/kg bw 

(35g) 5076.99 

(1000g) 2195.95 

Row Spacing: 0 inches 

Bandwidth: 0 inches 

Unincorporation: 100% 

 

Row/Band/In-furrow applications 

 

Liquid N/A 

Intermediate Calculations Intermediate Calculations 

# rows acre-1: N/A mg a.i./1000 ft row: N/A 

row length (ft): N/A bandwidth: N/A 

lb ai/1000 ft row: N/A mg a.i./ft2: N/A 

bandwidth (ft): N/A exposed mg a.i./ft2: N/A 

mg ai/ft2: N/A 

exposed mg ai/ft2: N/A 

 

LD50 ft-2 N/A 

 

wgt class 

(grams) 

wgt class 

(grams) 

Avian 20 N/A Avian 20 N/A 

 100 N/A 100 N/A 

 1000 N/A 1000 N/A 

Mammal 15 N/A Mammal 15 N/A 

 35 N/A 35 N/A 

 1000 N/A 1000 N/A 

 

 

Broadcast applications 

Liquid 

Intermediate Calculations 

mg ai/ft2: 3.90 

 

LD50 ft-2 

 

wgt class 

(grams) 

Avian 20 0.12 

 100 0.02 

 1000 0.00 
133 

2. TerrPlant 

TerrPlant v. 1.2.2 

Green values signify user inputs (Tables 1, 2 and 4). 

Input and output guidance is in popups indicated by red arrows. 

 

Table 1. Chemical Identity. 

Chemical Name Sulfentrazone 

PC code 129081 

Use Apple 

Application Method Spray 

Application Form Ground Application 

Solubility in Water 

(ppm) 400 

 

Table 2. Input parameters used to derive EECs. 

Input Parameter Symbol Value Units 

Application Rate A 0.375 y 

Incorporation I 1 none 

Runoff Fraction R 0.05 none 

Drift Fraction D 0.01 none 

 

Table 3. EECs for Sulfentrazone. Units in y. 

Description Equation EEC 

Runoff to dry areas (A/I)*R 0.01875 

Runoff to semi-aquatic areas (A/I)*R*10 0.1875 

Spray drift A*D 0.00375 

Total for dry areas ((A/I)*R)+(A*D) 0.0225 

Total for semi-aquatic areas ((A/I)*R*10)+(A*D) 0.19125 

 

Table 4. Plant survival and growth data used for RQ derivation. Units are in y. 

 Seedling Emergence Vegetative Vigor 

Plant type EC25 NOAEC EC25 NOAEC 

Monocot 0.023 0.019 0.012 0.006 

Dicot 0.011 0.006 0.00052 0.00044 

 

Table 5. RQ values for plants in dry and semi-aquatic areas exposed to Sulfentrazone through runoff 

and/or spray drift.* 

Mammal 15 0.04 

 35 0.02 

 1000 0.00 

 

Formulas used in the calculations are in the User's Guide 
134 

Plant Type Listed Status Dry Semi-Aquatic Spray Drift 

Monocot non-listed 0.98 8.32 0.31 

Monocot listed 1.18 10.07 0.63 

Dicot non-listed 2.05 17.39 7.21 

Dicot listed 3.75 31.88 8.52 

*If RQ > 1.0, the LOC is exceeded, resulting in potential for risk to that plant group. 

G. Ecological Incident Reports for Sulfentrazone 

Ecological Incident Reports for Sulfentrazone 

Table D1. Ecological Incidents Associated with Exposure to Sulfentrazone Via Drift, Runoff, 

and Carryover 

Monday, January 13, 2014

PC_Code INCIDENT_ID* USE 

SITE 

START 

DATE STATE COUNTY YEAR TOTAL 

MAG CERTAINTY FORMULATION APPL_METHOD

129081 I013636‐009 Soybean 06‐

May‐02 MN MOWER 2002 145

acres Possible 

129081 I013636‐019 Soybean 02‐

May‐02 IA BLACK

HAWK 2002 47

acres Possible 

129081 I013636‐020 Soybean 24‐Apr‐

02 IA MITCHELL 2002 74

acres Possible 

129081 I013636‐021 Soybean 23‐Apr‐

02 IA BREMER 2002 Possible 

129081 I014102‐001 Soybean 15‐

May‐03 AR Prairie 2003 250

acres Possible Granular 

129081 I014103‐001 Soybean 15‐

May‐03 AR Arkansas 2003 300

acres Possible Granular 

129081 I014104‐001 Soybean 01‐

May‐03 AR Randolph 2003 45

acres Possible Granular 

129081 I014106‐001 Soybean 15‐

May‐03 AR Arkansas 2003 227

acres Possible Granular 

129081 I014108‐001 Soybean 01‐

May‐03 AR Randolph 2003 228

acres Possible Granular 

129081 I014702‐008 N/R 12‐

May‐02 IA Grundy 2002 580

acres Possible N/R N/R

129081 I014702‐010 Soybeans 01‐

May‐03 IA Worth 2003 108

acres Probable Water soluble

packet N/R

129081 I014702‐011 Soybeans 26‐Apr‐

03 IA Worth 2003 40

acres Probable Water soluble

packet N/R

129081 I014702‐012 Soybeans 28‐Apr‐

03 IA Emmet 2003 150

acres Probable Water soluble

packet N/R

129081 I014702‐056 Soybean 05‐

May‐03 IA Pocahontas 2003 253

acres Possible Emulsifiable conc. Broadcast

129081 I014702‐057 Soybean 05‐

May‐03 IA Pocahontas 2003 251

Acres Possible Emulsifiable conc. Broadcast
135 

129081 I015175‐001 Soybean 10‐

May‐04 AR Ashley 2004 5,000

acres Probable Granular Spray

129081 I016225‐001 N/R 05‐Apr‐

05 IL Fayette 2005 1 acre Possible Granular Spray

129081 I024871‐003 Industrial

site OR Marion 2012

partial

loss of 8

ac

Possible N/R

*All incidents involved plants 

H. ECOTOX Database Bibliography for Sulfentrazone

ECOTOX Run 

Open literature studies were identified using EPA’s ECOTOXicology database (ECOTOX) 

(USEPA, 2007c), which employs a literature search engine for locating chemical toxicity data 

for aquatic life, terrestrial plants, and wildlife. 

Papers that were Accepted for ECOTOX 

The following papers were not used in the quantitative risk assessment for Sulfentrazone because 

they did not yield a toxicity endpoint which was lower than the comparable endpoint obtained 

from a toxicity study submitted by the registrant. 

Sulfentrazone Refresh Acceptable Bibliography November 2013 

 1. Brandenberger, L. P.; Shrefler, J. W.; Webber III, C. L.; Talbert, R. E.; Payton, M. E.; Wells, L. K., and 

McClelland, M. Preemergence Weed Control in Direct-Seeded Watermelon. 

PHY,POPSOIL,ENV,MIXTURE; 2005; 19, (3): 706-712. 

Rec #: 10 

Call Number: LITE EVAL CODED (SFZ), NO MIXTURE (BS,CMZ) 

Notes: EcoReference No.: 151988 

Chemical of Concern: BS,CMZ,EFL,NPM,SFZ 

 2. Brown, D. and Masiunas, J. Evaluation of Herbicides for Pumpkin (Cucurbita spp.). GRO,PHY,POP. 

Department of Natural Resources and Environmental Sciences,University of Illinois,Urbana,IL////: 

SOIL,ENV,MIXTURE; 2002; 16, (2): 282-292. 

Rec #: 120 

Call Number: LITE EVAL CODED (SFZ), OK (CMZ), WEEDS MANUAL (FMC) 

Notes: EcoReference No.: 120400 

Chemical of Concern: CMZ,DMM,EFL,FMC,IZX,SFZ 

 3. Daugrois, J. H.; Hoy, J. W., and Griffin, J. L. Protoporphyrinogen Oxidase Inhibitor Herbicide Effects on 

Pythium Root Rot of Sugarcane, Pythium Species, and the Soil Microbial Community. 

GRO,PHY,POPSOIL,ENV; 2005; 95, (3): 220-226. 

Rec #: 140 

Call Number: LITE EVAL CODED (FMX,SFZ) 

Notes: EcoReference No.: 107864 

Chemical of Concern: AZF,FMX,SFZ 

 4. Ewell, W. S.; Gorsuch, J. W.; Kringle, R. O.; Robillard, K. A., and Spiegel, R. C. Simultaneous Evaluation of 

the Acute Effects of Chemicals on Seven Aquatic Species. MORAQUA; 1986; 5, (9): 831-840. 

Rec #: 170 

Call Number: LITE EVAL CODED (CuS,DHB,ETHN,MOL,NFEDTA,NaCN,PCP,TML,ZnS) 
136 

Notes: EcoReference No.: 11951 

Chemical of Concern: 

AN,CoCl,CuS,DHB,ETHN,K2Cr2O7,MOL,NFEDTA,NHSO4,NaCN,NaHCT,PCP,PL,TML,ZnS 

 5. Figueroa, R.; Doohan, D., and Cardina, J. Efficacy and Selectivity of Promising Herbicides for Common 

Groundsel Control in Newly Established Strawberry. GRO,PHY,POPSOIL,ENV,MIXTURE; 2005; 

15, (2): 261-266. 

Rec #: 250 

Call Number: LITE EVAL CODED (FMC,SFZ), OK (MTL,PDM,SZ) 

Notes: EcoReference No.: 157325 

Chemical of Concern: DMM,EFS,FMC,MTL,NPP,PDM,SFZ,SZ,TRB 

 6. Fronning, B. E. and Kegode, G. O. Biennial Wormwood (Artemisia biennis) Early-Season Control with 

Herbicides. POP. Department of Plant Sciences,North Dakota State University,Fargo,ND,USA//: 

SOIL,ENV,MIXTURE; 2004; 18, (3): 611-618. 

Rec #: 270 

Call Number: LITE EVAL CODED (FTS,SFZ), NO MIXTURE (BT) 

Notes: EcoReference No.: 158820 

Chemical of Concern: ACF,BT,FTS,SFZ 

 7. Gorsuch, J. W.; Kringle, R. O., and Robillard, K. A. Chemical Effects on the Germination and Early Growth 

of Terrestrial Plants. GRO,NOCSOIL,ENV; 1990: 49-58. 

Rec #: 70 

Call Number: LITE EVAL CODED (DHB,NaCN), OK (CuS,ETHN,MOL,PCP,TML,ZnCl2) 

Notes: EcoReference No.: 49660 

Chemical of Concern: 

AN,CoCl,CuS,DHB,ETHN,K2Cr2O7,MOL,NHSO4,NaCN,NaHCT,NiCl,PCP,PL,TML,ZnCl2 

 8. Grey, T. L.; Bridges, D. C., and Brecke, B. J. Response of Seven Peanut (Arachis hypogaea) Cultivars to 

Sulfentrazone. PHY,POPSOIL,ENV; 2000; 14, 51-56. 

Rec #: 160 

Call Number: LITE EVAL CODED (SFZ), NO EFFECT (PAQT,PDM,PQT) 

Notes: EcoReference No.: 59443 

Chemical of Concern: EFL,IAZ,PAQT,PDM,PQT,SFZ 

 9. Isgrigg III, J. Ecological Adaptations of Annual Bluegrass to Plant Growth Regulators and Herbicides. 

BCM,GRO,PHY,POPSOIL,ENV,MIXTURE; 1999: 162 p. (UMI #9960156). 

Rec #: 100 

Call Number: LITE EVAL CODED 

(ATZ,DQT,FPD,FRM,GYP,OYZ,PBZ,PDM,PRM,PZM,SFZ,SZ,TXE), NO MIXTURE 

(Conazoles,NONA,PCZ,PPCP,PPCP2011) 

Notes: EcoReference No.: 121125 

 10. Johnson III, W. C. and Mullinix, B. G. Jr. Use of F6285 for Weed Control in Peanut: Efficacy and Crop 

Injury. PHY,POPSOIL,ENV,MIXTURE; 1994; 21, (1): 65-68. 

Rec #: 200 

Call Number: LITE EVAL CODED (MTL,SFZ), NO EFFECT (PDM), NO MIXTURE (BT,PAQT) 

Notes: EcoReference No.: 73923 

Chemical of Concern: BT,EFL,IZT,MTL,PAQT,PDM,SFZ 

 11. Krausz, R. F.; Kapusta, G., and Matthews, J. L. Sulfentrazone for Weed Control in Soybean (Glycine max). 

POPSOIL,ENV,MIXTURE; 1998; 12, (4): 684-689. 

Rec #: 190 

Call Number: LITE EVAL CODED (SFZ), NO EFFECT (FNP), NO MIXTURE (FNP), OK 

(CLNS) 
137 

Notes: EcoReference No.: 63152 

Chemical of Concern: CLNS,FNP,FZFP,IMQ,MBZ,SFZ 

 12. Legleiter, T. R.; Bradley, K. W., and Massey, R. E. Glyphosate-Resistant Waterhemp (Amaranthus rudis) 

Control and Economic Returns with Herbicide Programs in Soybean. 

POP,REPSOIL,ENV,MIXTURE; 2009; 23, (1): 54-61. 

Rec #: 20 

Call Number: LITE EVAL CODED (ACR,FMX,LCF,SFZ), NO MIXTURE (GYP,MTC) 

Notes: EcoReference No.: 152916 

Chemical of Concern: ACF,ACR,FMX,GYP,LCF,MBZ,MTC,SFZ 

 13. Lyon, D. J. and Wilson, R. G. Chemical Weed Control in Dryland and Irrigated Chickpea. 

GRO,PHY,POPSOIL,ENV,MIXTURE; 2005; 19, (4): 959-965. 

Rec #: 30 

Call Number: LITE EVAL CODED (SFZ), OK (PDM) 

Notes: EcoReference No.: 156872 

Chemical of Concern: EFL,IXF,IZT,PDM,PYD,SFZ 

 14. Martinez, C. O.; Silva, C. M. M. S.; Fay, E. F.; De Maia, A. H. N.; Abakerli, R. B., and Durrant, L. R. 

Degradation of the Herbicide Sulfentrazone in a Brazilian Typic Hapludox Soil. POPENV; 2008; 

40, (4): 879-886. 

Rec #: 280 

Call Number: LITE EVAL CODED (SFZ) 

Notes: EcoReference No.: 163252 

Chemical of Concern: SFZ 

 15. Nelson, K. A. Soybean (Glycine max (L.) Merr) Growth and Development, White Mold (Sclerotinia 

sclerotiorum (Lib.) de Bary) Incidence, and Yellow Nutsedge (Cyperus esculentus L.) Control as 

Affected by Glyphosate and Other Herbicides. 

BCM,GRO,POP,REPSOIL,ENV,INJECT,MIXTURE; 2000: 279 p. (UMI# 9971967). 

Rec #: 180 

Call Number: LITE EVAL CODED (CLNS,CRM,GFS,GYPI,SFZ), NO CONC 

(FMC,FSF,LCF,OXF), NO MIXTURE (BT,CLT,IZP,SXD), NO REVIEW (FMC,FSF,LCF,OXF) 

Notes: EcoReference No.: 120063 

 16. Nelson, K. A.; Renner, K. A., and Hammerschmidt, R. Effects of Protoporphyrinogen Oxidase Inhibitors on 

Soybean (Glycine max L.) Response, Sclerotinia sclerotiorum Disease Development, and 

Phytoalexin Production by Soybean. BCM,CEL,GRO,POP. Department of Agronomy, University 

of Missouri, Columbia, MO 65211//: SOIL,ENV,MIXTURE; 2002; 16, (2): 353-359. 

Rec #: 110 

Notes: EcoReference No.: 120109 

 17. Padilla, S.; Corum, D.; Padnos, B.; Hunter, D. L.; Beam, A.; Houck, K. A.; Sipes, N.; Kleinstreuer, N.; 

Knudsen, T.; Dix, D. J., and Reif, D. M. Zebrafish Developmental Screening of the ToxCast Phase I 

Chemical Library. NOC. Padilla.Stephanie@epa.gov//National Health and Environmental Effects 

Research Laboratory, Office of Research and Development, US Environmental Protection Agency, 

Research Triangle Park, NC 27712//: AQUA; 2012; 33, (2): 174-187. 

Rec #: 260 

 18. Pandian, V. Evaluation of Nightshade (Solanum spp.) and Groundcherry Species (Physalis spp.) Response to 

Herbicides. GRO,PHY,POPSOIL,ENV; 2005: 144 p. (UMI# 1426449). 

Rec #: 40 

Call Number: LITE EVAL CODED (OXF,SFZ), OK (DCPA,DQTBr,FMX,MB,MTC,PQT) 
138 

Notes: EcoReference No.: 159584 

Chemical of Concern: 

ACFNa,CFE,DCPA,DQTBr,FMX,HFS,IZT,IZX,MB,MBZ,MTC,NPP,OXF,PMSM,PQT,PYD,RIM

,SFS,SFZ 

 19. Reynolds, T. Comparative Effects of Aromatic Compounds on Inhibition of Lettuce Fruit Germination. 

REPSOIL,ENV; 1978; 42, 419-427. 

Rec #: 80 

Call Number: LITE EVAL CODED (BZO,DHB,MCRE,NATL,OCRE,PCRE,SCA), TARGET2012 

(NATL) 

Notes: EcoReference No.: 42996 

Chemical of Concern: BZO,DHB,MCRE,NATL,OCRE,PCRE,PL,SCA,VNL 

 20. Richardson, R. J. and Zandstra, B. H. Evaluation of Flumioxazin and Other Herbicides for Weed Control in 

Gladiolus. GRO,PHY,POP,REP. rorichar@yahoo.com//Department of Horticulture, Michigan State 

University, East Lansing, MI 48824////: SOIL,ENV,MIXTURE; 2006; 20, (2): 394-398. 

Rec #: 50 

Call Number: LITE EVAL CODED (PDM,SFZ), NO ENDPOINT (CMZ,IXB,OXF), OK 

(FMX,LNR,MTC,OYZ,PMT) 

Notes: EcoReference No.: 156786 

Chemical of Concern: CMZ,FMX,HSF,IAZ,IXB,IZX,LNR,MTC,OXF,OYZ,PDM,PMT,RIM,SFZ 

 21. ---. Weed Control in Christmas Trees with Flumioxazin and Other Residual Herbicides Applied Alone or in 

Tank Mixtures. GRO,PHY,POPSOIL,ENV,MIXTURE; 2009; 19, (1): 181-186. 

Rec #: 240 

Call Number: LITE EVAL CODED (IXB,OXF,SFZ), NO MIXTURE (PDM), OK (FMX,SZ) 

Notes: EcoReference No.: 157027 

Chemical of Concern: FMX,HSF,IXB,OXF,PDM,SFZ,SZ 

 22. Shoup, D. E.; Al-Khatib, K., and Peterson, D. E. Common Waterhemp (Amaranthus rudis) Resistance to 

Protoporphyrinogen Oxidase-Inhibiting Herbicides. GRO,PHYSOIL,ENV,MIXTURE; 2003; 51, 

(2): 145-150. 

Rec #: 60 

Call Number: LITE EVAL CODED (SFZ), NO MIXTURE (DZ,MLN), OK (FSF,GYP,LCF,PAQT) 

Notes: EcoReference No.: 162453 

Chemical of Concern: ACF,DZ,FSF,GYP,IZT,LCF,MLN,PAQT,SFZ,THF 

 23. Talbert, R. E.; Schmidt, L. A.; Lovelace, M. L., and Scherder, E. F. Field Evaluation of Herbicides on Small 

Fruit, Vegetable, and Ornamental Crops, 1999. PHY,POPSOIL,ENV; 2000: 1-22. 

Rec #: 210 

Call Number: LITE EVAL CODED (OXF,SFZ), NO ENDPOINT (GYPI,GYPT), NO MIXTURE 

(BT,CLNS,CMZ,FMC,FMCP,FSF,FTS,GFSNH,LCF,OYZ,QZFPE,SXD,SZ), OK 

(DU,LNR,MTC,MTL,PHMD,TFN) 

Notes: EcoReference No.: 153250 

Chemical of Concern: 

AZF,BT,CFE,CLNS,CMZ,CPR,DEF,DMM,DU,FFC,FMC,FMCP,FSF,FTS,FXPM,GFSNH,GYPI,

GYPT,IAZ,IZT,IZX,LCF,LNR,MTC,MTL,OXF,OYZ,PHMD,PYD,QZFPE,RIM,SFZ,SXD,SZ,TF

N,TPZ,TSF 

 24. Thienpont, B.; Tingaud-Sequeira, A.; Prats, E.; Barata, C.; Babin, P. J., and Raldua, D. Zebrafish 

Eleutheroembryos Provide a Suitable Vertebrate Model for Screening Chemicals that Impair 

Thyroid Hormone Synthesis. BCM,CEL,MOR. Drpqam@Cid.csic.es//: AQUA; 2011; 45, (17): 

7525-7532 (Author Communication Used). 

Rec #: 230 

Call Number: LITE EVAL CODED (DHB,ETU,Halides,KI,LNR,MZB,NaBr,NaNO3) 

Notes: EcoReference No.: 155099 
139 

Chemical of Concern: 

AMTL,BPA,DDT,DHB,ETU,Halides,KI,LNR,MZB,NaBr,NaNO3,PBDE,PFOA,PFOS,PPCP,PPCP

2011,SMX 

 25. Thornton, M.; Miller, J.; Hutchinson, P., and Alvarez, J. Response of Potatoes to Soil-Applied Insecticides, 

Fungicides, and Herbicides. PHY,POPSOIL,ENV; 2010; 53, (4): 351-358. 

Rec #: 220 

Call Number: LITE EVAL CODED (ADC,AZX,IMC,NNCT,OML,PRT,SFZ) 

Notes: EcoReference No.: 154191 

Chemical of Concern: ADC,AZX,IMC,NNCT,OML,PRT,SFZ,TMX 

 26. VanGessel, M. J. Control of Perennial Weed Species as Seedlings with Soil-Applied Herbicides. MOR,POP. 

M.J. Vangessel, Research and Education Center, University of Delaware, Georgetown, DE 19947, 

United States//: SOIL,ENV,MIXTURE; 1999; 13, (2): 425-428. 

Rec #: 90 

Call Number: LITE EVAL CODED (ATZ,SFZ), NO ENDPOINT (CLNS,CMZ,FTS,LNR,PDM), 

NO MIXTURE (CRM), OK (MTL) 

Notes: EcoReference No.: 62724 

Chemical of Concern: ATZ,CLNS,CMZ,CRM,FTS,IMQ,LNR,MBZ,MTL,PDM,SFZ 

 27. VanGessel, M. J.; Monks, D. W., and Johnson, Q. R. Herbicides for Potential Use in Lima Bean (Phaseolus 

lunatus) Production. PHY,POPSOIL,ENV,MIXTURE; 2000; 14, 279-286. 

Rec #: 130 

Call Number: LITE EVAL CODED (BT,CLNS,LCF,SFZ), NO MIXTURE (FTS,MTL) 

Notes: EcoReference No.: 59708 

Chemical of Concern: BT,CLNS,FTS,IZT,IZX,LCF,MTL,SFZ 

 28. Viator, B. J.; Griffin, J. L., and Ellis, J. M. Red Morningglory (Ipomoea coccinea) Control with Sulfentrazone 

and Azafeniden Applied at Layby in Sugarcane (Saccharum spp.). 

GRO,PHY,POPSOIL,ENV,MIXTURE; 2002; 16, 142-148. 

Rec #: 150 

Call Number: LITE EVAL CODED (ATZ,SFZ), NO EFFECT (24D,24DXY,DMB,PDM,TFN), NO 

MIXTURE (24D,24DXY,DMB), OK (DU) 

Notes: EcoReference No.: 62981 

Chemical of Concern: 24D,24DXY,ATZ,AZF,DMB,DU,MBZ,PDM,SFZ,TFN,TRB 

 
140 

Target Papers 

The following papers were identified as providing toxicity information to target species, in this 

case weed species. These herbicide efficacy studies did not provide toxicity endpoints which 

were useful for quantitative risk assessment of Sulfentrazone. 

Sulfentrazone Refresh Target Bibliography November 2013 

 1. . New herbicide for soybean. 2008 June 19, issue 6. 

Rec #: 2080 

Call Number: TARGET2012 (SFZ) 

Notes: Chemical of Concern: SFZ 

Abstract: Keywords: Internet resource 

1022986436 

 2. Ashigh, J. and Hall, J. C. Bases for Interactions between Saflufenacil and Glyphosate in Plants. 2010; 58, 

7335-7343. 

Rec #: 2310 

Call Number: TARGET2012 (SFZ) 

Notes: Chemical of Concern: SFZ 

Abstract: Number of Volumes: 12 

Ashigh, Jamshid Hall, J. Christopher 

 3. Brosnan, J. T.; Breeden, G. K.; Henry, G. M., and Walls, F. R. Sulfentrazone and Carfentrazone Accelerate 

Broadleaf Weed Control with Metsulfuron. 2012; 26, 549-553. 

Rec #: 2340 

Call Number: TARGET2012 (SFZ) 

Notes: Chemical of Concern: SFZ 

Abstract: Number of Volumes: 3 

Brosnan, James T. Breeden, Gregory K. Henry, Gerald M. Walls, Franklin R. 

 4. Brosnan, James T.; Armel, Gregory R.; Klingeman, William E. III; Breeden, Gregory K.; Vargas, Jose J., and 

Flanagan, Philip C. Selective Star-of-Bethlehem Control with Sulfentrazone and Mixtures of 

Mesotrione and Topramezone with Bromoxynil and Bentazon in Cool-season Turfgrass. 2010; 20, 

315-318. 

Rec #: 2110 

Call Number: TARGET2012 (SFZ) 

 5. Buckelew, J. K. Orchard Floor Management in Young Peach [Prunus persica (L.) Batsch.]: Effects of 

Irrigation, Vegetation-Free Width, and Certain PRE Herbicides. GRO,POPSOIL,ENV,MIXTURE; 

2009: 117 p. (UMI# 3377542). 

Rec #: 2650 

Call Number: TARGET2012 (FMX,NFZ,OYZ,SFZ), WEEDS (FMX,NFZ,OYZ,SFZ) 

Notes: EcoReference No.: 121257 

Chemical of Concern: FMX,HSF,NFZ,OYZ,RIM,SFZ,TRB 

 6. Cohen, R.; Eizenberg, H.; Edelstien, M.; Horev, C.; Lande, T.; Porat, A.; Achdari, G., and Hershenhorn, J. 

Evaluation of Herbicides for Selective Weed Control in Grafted Watermelons. GRO. 

eizenber@volcani.agri.gov.il//Newe Yaar res Ctr, ARO, Dept Weed Res, IL-30095 Ramat 

Yishay,Israel////: SOIL,ENV; 2008; 36, (1): 66-73. 

Rec #: 2660 

Call Number: TARGET2012 (CMZ,OXF,PDM,SFZ,TFN), WEEDS (CMZ,OXF,PDM,SFZ,TFN) 

Notes: EcoReference No.: 151483 

Chemical of Concern: CMZ,CSF,OXF,PDM,SFZ,TFN 

 7. Dayan, F. E.; Weete, J. D.; Duke, S. O., and Hancock, H. G. Soybean (Glycine max) Cultivar Differences in 

Response to Sulfentrazone. GRO,REP. J.D. Weete, Dept. of Botany and Microbiology, Auburn 

University, Auburn, AL 36849, United States//: SOIL,ENV; 1997; 45, (5): 634-641. 

Rec #: 2670 

Call Number: TARGET2012 (SFZ) 
141 

Notes: EcoReference No.: 163300 

Chemical of Concern: SFZ 

 8. Elezovic, Igor; Datta, Avishek; Vrbnicanin, Sava; Glamoclija, Djordje; Simic, Milena; Malidza, Goran, and 

Knezevic, Stevan Z. Yield and yield components of imidazolinone-resistant sunflower (Helianthus 

annuus L.) are influenced by pre-emergence herbicide and time of post-emergence weed removal. 

2012 Mar 14-; 128, (0): 137-146. 

Rec #: 260 

Call Number: TARGET2012 (SFZ) 

Notes: Chemical of Concern: SFZ 

 9. Etheredge, Luke M.; Griffin, James L., and Boudreaux, Joseph M. Nutsedge (Cyperus Spp.) Control 

Programs in Sugarcane. 2010; 30, 67-80. 

Rec #: 2130 

Call Number: TARGET2012 (SFZ) 

Notes: Chemical of Concern: SFZ 

Abstract: Keywords: Internet resource 

Includes references 1022998992 

 10. Frost, P. and Barnes, G. Evaluation of New Herbicides for Management of Black Nightshade (Solanum 

nigrum) in Processing Tomatoes. POP. Serve-Ag Research,Devonport, Tasmania,Australia//: 

SOIL,ENV; 2003; 613, 201-203. 

Rec #: 2840 

Call Number: NO ENDPOINT (OXF), TARGET2012 (BT,CMZ,FMX,MTC,OXF,PDM,PMT,SFZ), 

WEEDS (BT,CMZ,FMX,MTC,OXF,PDM,PMT,SFZ) 

Notes: EcoReference No.: 159710 

Chemical of Concern: AZF,BT,CMZ,DMM,FMX,IXF,MTC,OXF,PDM,PMT,RIM,SFZ 

 11. Gonzini, L. C.; Hart, S. E., and Wax, L. M. Herbicide Combinations for Weed Management in GlyphosateResistant Soybean (Glycine max). PHY,POP. hart@aesop.rutgers.edu//S.E. Hart, Rutgers 

University, New Brunswick, NJ 08901, United States//: SOIL,ENV,MIXTURE; 1999; 13, (2): 354-

360. 

Rec #: 2750 

Call Number: TARGET2012 (ACR,CLNSM,CRM,GYPI,PDM,SFZ), WEEDS 

(ACR,CLNSM,CRM,GYPI,PDM,SFZ) 

Notes: EcoReference No.: 72888 

Chemical of Concern: ACR,CLNSM,CRM,GYPI,IZT,MBZ,PDM,SFZ 

 12. Graber, E. R.; Tsechansky, L.; Gerstl, Z., and Lew, B. High Surface Area Biochar Negatively Impacts 

Herbicide Efficacy. GROSOIL,ENV; 2012; 353, 95-106. 

Rec #: 2850 

Call Number: WEEDS (MTC,SFZ) 

Notes: EcoReference No.: 163761 

Chemical of Concern: MTC,SFZ 

 13. Hutchinson, P. J. S. Common Lambsquarters and Hairy Nightshade Control in Potato with Dimethenamid-p

Alone and in Tank Mixtures and Comparison of Control by Dimethenamid-p with S-metolachlor 

and Metolachlor. 2012; 26, 279-283. 

Rec #: 2430 

Call Number: TARGET2012 (SFZ) 

Notes: Chemical of Concern: SFZ 

Abstract: Number of Volumes: 2 

Hutchinson, Pamela J. S. 

 14. Jhala, A. J. ; Ramirez, A. H. M., and Singh, M. Rimsulfuron Tank Mixed with Flumioxazin, Pendimethalin, 

or Oryzalin for Control of Broadleaf Weeds in Citrus. 2012; 22, 638-643. 

Rec #: 2440 

Call Number: TARGET2012 (SFZ) 

Notes: Chemical of Concern: SFZ 

Abstract: Number of Volumes: 5 

Jhala, Amit J. Ramirez, Analiza H. M. Singh, Megh 

 15. Li, Z.; Walker, R. H.; Wehtje, G., and Hancock, H. G. Use of Seedling Growth Parameters to Classify 
142 

Soybean (Glycine max) Cultivar Sensitivity to Sulfentrazone. GRO,POPSOIL,ENV; 1999; 13, (3): 

530-535. 

Rec #: 2680 

Call Number: TARGET2012 (SFZ) 

Notes: EcoReference No.: 163303 

Chemical of Concern: SFZ 

 16. ---. Using Electrolyte Leakage to Detect Soybean (Glycine max) Cultivars Sensitive to Sulfentrazone. 

CELSOIL,ENV; 2000; 14, 699-704. 

Rec #: 2800 

Call Number: TARGET2012 (SFZ), WEEDS (SFZ) 

Notes: EcoReference No.: 59539 

Chemical of Concern: SFZ 

 17. Li, Z.; Wehtje, G. R., and Walker, R. H. Physiological Basis for the Differential Tolerance of Glycine max to 

Sulfentrazone During Seed Germination. ACC,GROSOIL,ENV; 2000; 48, 281-285. 

Rec #: 2770 

Call Number: TARGET2012 (SFZ) 

Notes: EcoReference No.: 59538 

Chemical of Concern: SFZ 

 18. Main, C. L.; Mueller, T. C.; Hayes, R. M.; Wilcut, J. W.; Peeper, T. F.; Talbert, R. E., and Witt, W. W. 

Sulfentrazone Persistence in Southern Soils: Bioavailable Concentration and Effect on a Rotational 

Cotton Crop. GRO,PHY,POPSOIL,ENV; 2004; 18, 346-352. 

Rec #: 2690 

Call Number: NO EFFECT (GYP), TARGET2012 (GYP,SFZ) 

Notes: EcoReference No.: 163304 

Chemical of Concern: GYP,SFZ 

 19. McCullough, P. E.; de Barreda, D. G., and Raymer, P. Nicosulfuron Use with Foramsulfuron and 

Sulfentrazone for Late Summer Goosegrass (Eleusine indica) Control in Bermudagrass and Seashore 

Paspalum. 2012; 26, 376-381. 

Rec #: 2520 

Call Number: TARGET2012 (SFZ) 

Notes: Chemical of Concern: SFZ 

Abstract: Number of Volumes: 2 

McCullough, Patrick E. Gomez de Barreda, Diego Raymer, Paul 

 20. Miller, R. T.; Soltani, N.; Robinson, D. E.; Kraus, T. E., and Sikkema, P. H. Soybean (Glycine max) cultivar 

tolerance to saflufenacil. 2012; 92, 1319-1328. 

Rec #: 2540 

Call Number: TARGET2012 (SFZ) 

Notes: Chemical of Concern: SFZ 

Abstract: Number of Volumes: 7 

Miller, Robert T. Soltani, Nader Robinson, Darren E. Kraus, Trevor E. Sikkema, Peter H. Robinson, 

Darren/A-3959-2013 

 21. Niekamp, J. W. and Johnson, W. G. Weed Management with Sulfentrazone and Flumioxazin in No-Tillage 

Soyabean (Glycine max). POPSOIL,ENV,MIXTURE; 2001; 20, 215-220. 

Rec #: 2810 

Call Number: NO MIXTURE (CRM,PDM), OK (CMZ,FMX), TARGET MANUAL (SFZ) 

Notes: EcoReference No.: 63898 

Chemical of Concern: CMZ,CRM,FMX,PDM,SFZ 

 22. Niekamp, J. W.; Johnson, W. G., and Smeda, R. J. Broadleaf Weed Control with Sulfentrazone and 

Flumioxazin in No-Tillage Soybean (Glycine max). PHY,POP. J.W. Niekamp, Department of 

Agronomy, University of Missouri, Columbia, MO 65211//: SOIL,ENV,MIXTURE; 1999; 13, (2): 

233-238. 

Rec #: 2730 

Call Number: NO EFFECT (ALSV,CLT,GYP,MOIL), NO MIXTURE 

(ALSV,CLT,CRM,GYP,MOIL), OK (FMX), TARGET MANUAL (SFZ) 

Notes: EcoReference No.: 72819 

Chemical of Concern: ALSV,CLT,CRM,FMX,GYP,IMQ,MBZ,MOIL,NHSO4,SFZ 
143 

 23. No-Riang, A. and Bhromsiri, A. Effects of Some Preemergence Herbicides on Nodulation, N2-Fixation, 

Growth and Yield of Soybean. BCM,GRO,PHY. Department of Soil Science and Conservation, 

Faculty of Agriculture,Chiang Mai University,Chiang Mai,Thailand//: SOIL,ENV; 2005; 17, 208-

213. 

Rec #: 2830 

Call Number: TARGET2012 (OXF,SFZ) 

Notes: EcoReference No.: 163616 

Chemical of Concern: IZT,OXF,SFZ 

 24. Ogbuchiekwe, E. J.; McGiffen, M. E. Jr.; Nunez, J., and Fennimore, S. A. Tolerance of Carrot to Low-Rate 

Preemergent and Postemergent Herbicides. GRO,PHY,POP. milt@ucr.edu//M.E. McGiffen Jr., 

Dept. of Botany and Plant Sciences, University of California, Riverside, CA 92521-0124//: 

SOIL,ENV; 2004; 39, (2): 291-296. 

Rec #: 2790 

Call Number: TARGET2012 (CLNSM,SFZ) 

Notes: EcoReference No.: 82420 

Chemical of Concern: CLNSM,DMM,HSF,IZX,RIM,SFZ 

 25. Olson, B. L. S.; Zollinger, R. K.; Thompson, C. R.; Peterson, D. E.; Jenks, B.; Moechnig, M., and Stahlman, 

P. W. Pyroxasulfone with and without Sulfentrazone in Sunflower (Helianthus annuus). 2011; 25, 

217-221. 

Rec #: 2550 

Call Number: TARGET2012 (SFZ) 

Notes: Chemical of Concern: SFZ 

Abstract: Number of Volumes: 2 

Olson, Brian L. S. Zollinger, Richard K. Thompson, Curtis R. Peterson, Dallas E. Jenks, Brian 

Moechnig, Mike Stahlman, Phillip W. 

 26. Pekarek, Ryan A.; Garvey, Paul V.; Monks, David W.; Jennings, Katherine M., and Macrae, Andrew W. 

Sulfentrazone Carryover to Vegetables and Cotton. 2010; 24, 20-24. 

Rec #: 2220 

Call Number: TARGET2012 (SFZ) 

Notes: Chemical of Concern: SFZ 

Abstract: Keywords: Internet resource 

Number of Volumes: 1 

Includes references 1022821111 

 27. Robinson, D. E.; McNaughton, K., and Soltani, N. Weed Management in Transplanted Bell Pepper 

(Capsicum annuum) with Pretransplant Tank Mixes of Sulfentrazone, S-metolachlor, and 

Dimethenamid-p. 2008; 43, 1492-1494. 

Rec #: 2240 

Call Number: TARGET2012 (SFZ) 

 28. Robinson, D. E. and McNaughton, K. E. Saflufenacil Carryover Injury Varies among Rotational Crops. 2012; 

26, 177-182. 

Rec #: 2600 

Call Number: TARGET2012 (SFZ) 

Notes: Chemical of Concern: SFZ 

Abstract: Number of Volumes: 2 

Robinson, Darren E. McNaughton, Kristen E. Robinson, Darren/A-3959-2013 

 29. Robinson, Darren E.; McNaughton, Kristen, and Sikkema, Peter H. Tolerance of tomato, pepper and potato to 

pre-emergence applications of saflufenacil. 2012 Dec; 42, (0): 230-233. 

Rec #: 120 

Call Number: TARGET2012 (SFZ) 

 30. Swantek, J. M.; Sneller, C. H., and Oliver, L. R. Evaluation of Soybean Injury from Sulfentrazone and 

Inheritance of Tolerance. GRO,PHY,POP. L.R. Oliver, Department of Agronomy, University of 

Arkansas, Fayetteville, AR 72704, United States//: SOIL,ENV; 1998; 46, (2): 271-277. 

Rec #: 2740 

Call Number: NO EFFECT (CLT), TARGET2012 (CLT,SFZ) 
144 

Notes: EcoReference No.: 64494 

Chemical of Concern: CLT,SFZ 

 31. Szmigielski, A. M.; Schoenau, J. J.; Johnson, E. N.; Holm, F. A.; Sapsford, K. L., and Liu, J. Development of 

a Laboratory Bioassay and Effect of Soil Properties on Sulfentrazone Phytotoxicity in Soil. 

GROSOIL,ENV; 2009; 23, 486-491. 

Rec #: 2860 

Call Number: TARGET2012 (SFZ) 

Notes: EcoReference No.: 163251 

Chemical of Concern: SFZ 

 32. ---. Effects of Soil Factors on Phytotoxicity and Dissipation of Sulfentrazone in Canadian Prairie Soils. 

GROSOIL,ENV; 2012; 43, (6): 896-904. 

Rec #: 2820 

Call Number: TARGET2012 (SFZ) 

Notes: EcoReference No.: 163250 

Chemical of Concern: SFZ 

 33. Taran, B.; Holm, F., and Banniza, S. Response of chickpea cultivars to pre- and post-emergence herbicide 

applications. 2013; 93, 279-286. 

Rec #: 2640 

Call Number: TARGET2012 (SFZ) 

Notes: Chemical of Concern: SFZ 

Abstract: Number of Volumes: 2 

Taran, B. Holm, F. Banniza, S. 

 34. Taylor-Lovell, S.; Wax, L. M., and Nelson, R. Phytotoxic Response and Yield of Soybean (Glycine max) 

Varieties Treated with Sulfentrazone or Flumioxazin. GRO,PHY,POP,REPSOIL,ENV; 2001; 15, 

(1): 95-102. 

Rec #: 2780 

Call Number: TARGET2012 (FMX,SFZ) 

Notes: EcoReference No.: 66974 

 35. Trezzi, M. M.; Felippi, C. L.; Mattei, D.; Silva, H. L.; Nunes, A. L.; Debastiani, C.; Vidal, R. A., and 

Marques, A. Multiple Resistance of Acetolactate Synthase and Protoporphyrinogen Oxidase 

Inhibitors in Euphorbia heterophylla Biotypes. GRO,MOR. Agronomy School of CEFET/PR, Pato 

Branco, Brazil//: SOIL,ENV; 2005; 40, (1): 101-109. 

Rec #: 2760 

Call Number: WEEDS (CLNS,FMC,FMX,FSF,LCF,MTS,SFZ) 

Notes: EcoReference No.: 106387 

 36. Wehtje, G. R.; Walker, R. H.; Grey, T. L., and Hancock, H. G. Response of Purple (Cyperus rotundus) and 

Yellow Nutsedges (C. esculentus) to Selective Placement of Sulfentrazone. ACC,GRO,MOR,REP. 

G.R. Wehtje, Department of Agronomy and Soils, Alabama Agricultural Experiment Stn., Auburn 

University, Auburn, AL 36849-5412, United States//: SOIL,ENV; 1997; 45, (3): 382-387. 

Rec #: 2700 

Call Number: WEEDS (SFZ) 

Notes: EcoReference No.: 163306 

Chemical of Concern: SFZ 

 37. Yenish, J. P. and Eaton, N. A. Weed Control in Dry Pea (Pisum sativum) Under Conventional and No-Tillage 

Systems. PHY,POP. Department of Crop and Soil Sciences,Washington State University, 

Pullman,WA//: SOIL,ENV,MIXTURE; 2002; 16, (1): 88-95. 

Rec #: 2710 

Call Number: TARGET MANUAL (BT,CLNS,FMC,FSF,FTS,SFZ) 

Notes: EcoReference No.: 159908 

 38. York, A. C.; Stewart, A. M.; Vidrine, P. R., and Culpepper, A. S. Control of Volunteer Glyphosate-Resistant 

Cotton in Glyphosate-Resistant Soybean. POP. Department of Crop Science,North Carolina State 

University,Raleigh,NC//: SOIL,ENV,MIXTURE; 2004; 18, (3): 532-539. 
145 

Rec #: 2720 

Call Number: TARGET2012 (CLNS,CRM,FMC,FSF,FTS,SFZ) 

Notes: EcoReference No.: 159909 

 39. Zobiole, L. H. S.; Oliveira Jr., R. S.; Kremer, R. J.; Constantin, J.; Yamada, T.; Castro, C.; Oliveira, F. A., 

and Oliveira Jr., A. Effect of glyphosate on symbiotic N2 fixation and nickel concentration in glyphosateresistant soybeans. 2010 Feb; 44, (2): 176-180. 

Rec #: 1920 

Papers Not Acceptable for Quantitative Risk Assessment 

There were 267 papers (not included here) that came up in the ECOTOX search that did not meet 

the minimum acceptability criteria for use by the EFED in risk assessment, and therefore, were 

excluded from the bibliography and were not used in the quantitative risk assessment of 

Sulfentrazone.