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Table of Contents

1.0 Executive Summary............................................................................................................. 5

2.0 HED Recommendations ...................................................................................................... 7

2.1 Data Deficiencies/Conditions of Registration.................................................................. 7

2.2 Tolerance Considerations................................................................................................. 9

2.2.1 Enforcement Analytical Method .................................................................................. 9

2.2.2 International Harmonization......................................................................................... 9

2.2.3 Recommended Tolerances............................................................................................ 9

2.2.4 Revisions to Petitioned-For Tolerances...................................................................... 10

2.3 Label Recommendations................................................................................................ 10

2.3.1 Recommendations from Residue Reviews................................................................. 10

2.3.2 Recommendations from Occupational Assessment ................................................... 11

3.0 Introduction........................................................................................................................ 11

3.1 Chemical Identity ........................................................................................................... 11

3.2 Physical/Chemical Characteristics................................................................................. 12

3.3 Pesticide Use Pattern...................................................................................................... 12

3.4 Anticipated Exposure Pathways..................................................................................... 17

4.0 Hazard Characterization and Dose-Response Assessment................................................ 18

4.1 Toxicology Studies Available for Analysis ................................................................... 18

4.2 Absorption, Distribution, Metabolism, & Excretion (ADME) ...................................... 18

4.2.1 Dermal Absorption ..................................................................................................... 18

4.3 Toxicological Effects ..................................................................................................... 18

4.4 Safety Factor for Infants and Children (FQPA Safety Factor)....................................... 20

4.4.1 Completeness of the Toxicology Database ................................................................ 20

4.4.2 Evidence of Neurotoxicity.......................................................................................... 20

4.4.3 Evidence of Sensitivity/Susceptibility in the Developing or Young Animal............. 21

4.4.4 Residual Uncertainty in the Exposure Database......................................................... 21

4.5 Toxicity Endpoints and Point of Departure Selections.................................................. 21

4.5.1 Dose-Response Assessment ....................................................................................... 21

4.5.2 Recommendation for Combining Routes of Exposures for Risk Assessment ........... 23

4.5.3 Cancer Classification and Risk Assessment Recommendation.................................. 23

4.5.4 Summary of Points of Departure and Toxicity Endpoints Used in Human-Health Risk 

Assessment................................................................................................................................ 23

5.0 Dietary Exposure and Risk Assessment ............................................................................ 24

5.1 Metabolite/Degradate Residue Profile ........................................................................... 24

5.1.1 Summary of Plant and Animal Metabolism Studies .................................................. 24

5.1.2 Residues of Concern Summary and Rationale ........................................................... 25

5.2 Food Residue Profile...................................................................................................... 25

5.3 Water Residue Profile .................................................................................................... 26

5.4 Dietary Risk Assessment................................................................................................ 27

5.4.1 Description of Residue Data Used in Dietary Assessment......................................... 27

5.4.3 Acute Dietary Risk Assessment ................................................................................. 27

5.4.4 Chronic Dietary Risk Assessment .............................................................................. 27

5.4.5 Cancer Dietary Risk Assessment................................................................................ 28

5.4.6 Summary Table........................................................................................................... 28

6.0 Residential (Non-Occupational) Exposure/Risk Characterization .................................... 28

6.1 Residential Handler Exposure........................................................................................ 28
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6.2 Post-Application Exposure............................................................................................. 31

6.3 Combined Exposure ....................................................................................................... 32

6.4 Residential Bystander Post-application Inhalation Exposure ........................................ 35

6.5 Spray Drift...................................................................................................................... 35

7.0 Aggregate Exposure/Risk Characterization....................................................................... 35

7.1 Acute Aggregate Risk .................................................................................................... 36

7.2 Short- and Intermediate-Term Aggregate Risk.............................................................. 36

7.3 Chronic Aggregate Risk................................................................................................. 37

7.4 Cancer Aggregate Risk................................................................................................... 37

8.0 Cumulative Exposure/Risk Characterization..................................................................... 38

9.0 Occupational Exposure/Risk Characterization .................................................................. 38

9.1 Short-/Intermediate-Term Handler Risk ........................................................................ 38

9.2 Short-/Intermediate-Post-application Risk..................................................................... 43

9.2.1 Dermal Post-application Risk..................................................................................... 43

9.2.2 Inhalation Post-application Risk................................................................................. 43

10.0 References.......................................................................................................................... 44

Appendix A. Toxicology Profile ................................................................................................. 45

Appendix B. Physical/Chemical Properties................................................................................. 49

Appendix C. Summary of Residue Data...................................................................................... 50

Appendix D. Review of Human Research................................................................................... 54
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1.0 Executive Summary

This assessment evaluates the petitions submitted by Interregional Research Project No. 4 (IR-4; 

PP# 1E7890 & 2E8020) and FMC (PP# 1F7838) that propose new tolerances for residues of 

sulfentrazone and its metabolites HMS and DMS in/on rhubarb, turnip roots and tops, sunflower 

subgroup 20B, succulent cowpea, succulent lima bean, succulent vegetable soybean, wheat 

(Spring), citrus fruit group 10-10, low-growing berry group 13-07, tree nut group 14 and 

pistachios, and nongrass animal feeds crop group 18. This assessment also evaluates the 

potential for enhanced sensitivity of infants and children, as required under the Food Quality 

Protection Act (FQPA) of 1996. 

Sulfentrazone is an aryl triazolinone herbicide used to control a variety of broadleaf weeds. The 

mode-of-action for controlling emerging weeds is by protoporphyrinogen oxidase (PPO) 

inhibition. Sulfentrazone acts by the same mechanism as the diphenyl ether herbicides in which 

membrane disruption is initiated by the inhibition of PPO in the chlorophyll biosynthetic 

pathway and leads to the subsequent build-up of toxic intermediates. Plants emerging from soils 

treated with sulfentrazone turn necrotic and die shortly after exposure to light.

The sulfentrazone end-use products (EPs) relevant for this registration request include Spartan®

Herbicide [EPA Reg. No. 279-3189; 75% dry-flowable (DF) formulation] and Spartan®4F 

Herbicide [EPA Reg. No. 279-3220; 4 lb/gal flowable-concentrate (FlC) formulation]. The 

petitioners request the amendment of these EP labels to incorporate new uses on rhubarb, turnips, 

sunflower subgroup 20B, succulent cowpea (regional registration, limited to TN), lima bean

(regional registration, limited to TN), succulent vegetable soybean, wheat (regional registration, 

limited to the Pacific Northwest), citrus fruit group 10-10, low-growing berry group 13-07, tree 

nut group 14, clover, alfalfa, and pistachios. These EPs are proposed for maximum seasonal 

rates of 0.1875-0.375 lb ai/A using ground or aerial equipment with pre-harvest intervals (PHIs) 

as low as 3 days.

Hazard Assessment

Sulfentrazone inhibits the enzyme PPO in target plants, and the results of mammalian toxicity 

studies were consistent with this mode of action, given that PPO is an important enzyme in the 

heme synthetic pathway in mammals. Specifically, toxicity reflective of disruption of heme 

synthesis (hematotoxicity) was observed in mice, rats, and dogs, and this was seen at about the 

same dose levels across species, except in the case of mice, where the effects were seen at a 

slightly higher dose. In addition, this hematotoxicity occurred around the same dose level from 

short- through long-term exposure without increasing in severity. Sulfentrazone caused 

developmental effects via the oral and dermal routes of exposure. Developmental effects, 

including decreased fetal body weights and reduced/delayed skeletal ossifications, were observed 

in both the oral and dermal developmental toxicity studies in the rat and at doses that were not 

maternally toxic, although clear no-observed adverse-effect levels (NOAELs) were attained in 

both studies. In the 2-generation reproduction study in rats, offspring effects such as decreased 

body weights and decreased litter survival were observed at doses that were maternally toxic 

(decreased body weight during gestation in both generations).

Although sulfentrazone is considered a developmental toxicant, the developing nervous system is 

not considered a selective target. A published non-guideline developmental neurotoxicity study 

in the rat by De Castro et al. (2007; MRID 47749201) with no established NOAEL failed to 
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demonstrate conclusively developmental neurotoxicity and yielded developmental effects more 

related to those observed in the rat 2-generation reproductive toxicity study for which a clear 

NOAEL was established. Acute and subchronic neurotoxicity studies with well-defined 

NOAELs indicate neurotoxic effects (e.g., an increased incidence of clinical signs of toxicity and 

motor activity changes) at relatively high administered doses [lowest-observed adverse-effect 

levels (LOAELs) of 750 mg/kg and 150(M)/180(F) mg/kg/day for acute and subchronic studies, 

respectively] that are more consistent with systemic toxicity rather than neurotoxicity. 

Furthermore, there is no evidence of neuropathology in any of the studies available for 

sulfentrazone. Carcinogenicity studies in rats and mice showed no evidence of increased 

incidence of tumor formation due to treatment with sulfentrazone and genotoxicity studies were 

all negative.

Food Residue Profile

Tolerances are currently established for residues of sulfentrazone and its metabolites under 40 

CFR §180.498. The nature of the residue in plants and livestock is adequately understood. 

There is an adequate residue analytical method for the purposes of tolerance enforcement. The 

submitted field trial residue data for turnip (roots and tops), rhubarb, wheat (grown in the Pacific 

Northwest only), tree nut group 14, citrus fruit group 10-10, and the berry and small fruit group 

13-07 are adequate. The field trial data reflect the proposed use patterns; an adequate number of 

trials were conducted in the appropriate geographic regions; and samples were analyzed for the 

residue of concern using validated data-collection methods. The storage intervals were also 

validated. Use of the Organization for Economic Co-operation and Development (OECD) 

tolerance-calculation procedures and the submitted residue data sets indicates that requested 

tolerance levels are not appropriate for several commodities (Section 2.2.3). A revised Section F 

is requested. For clover and alfalfa, additional residue data and a ruminant feeding study are 

required; therefore, these uses should be removed from the labels. The previously submitted 

residue data for sunflower seed are adequate to support the proposed crop subgroup tolerance for 

the combined residues of sulfentrazone, DMS, and HMS of 0.20 ppm in/on sunflower, subgroup 

20B. The established tolerances for the combined residues of sulfentrazone and its two 

metabolites of 0.15 ppm for pea, succulent, and bean, lima, succulent are being extrapolated to 

cowpea, succulent and soybean, vegetable, succulent. Pending submission of a revised Section 

B, analytical reference standards for sulfentrazone and DMS (see requirements under Submittal 

of Analytical Reference Standards), and a revised Section F, there are no residue chemistry 

issues that would preclude granting unconditional registrations for the requested uses of the 

commodities listed in Table 2.2.3. 

Exposure/Risk Assessment Characterization

Acute and chronic risk assessments were conducted for dietary exposure based on the existing 

and proposed uses. The acute and chronic assessments directly incorporated drinking water 

estimates. The acute and chronic (food and drinking water) analyses also assumed tolerancelevel residues for all commodities, 100% crop treated (%CT), and DEEM (ver. 7.81) default 

processing factors. All exposure and risk estimates were not of concern. A cancer dietary 

assessment was not conducted because sulfentrazone is classified as “not likely to be 

carcinogenic to humans.”

The proposed uses will not result in residential exposure; however, the currently registered turf 

use has been reassessed to reflect updates to HED’s 2012 Residential Standard Operating 

Procedures (SOPs). The residential exposures estimates were revised since they impact the 
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aggregate assessment for sulfentrazone. Since the levels of concern (LOC) for dermal exposure 

[margins of exposure (MOEs) <100] and inhalation exposure (MOEs <1000) are different, a total 

aggregated-risk index (ARI) approach was used for residential handlers. The combined dermal 

and inhalation exposure risk estimates for residential handlers are not of concern (i.e., ARI >1) at 

baseline for all scenarios. Residential dermal and incidental oral post-application risk estimates 

were greater than the LOC of 100 and, also, are not of concern.

Acute, chronic, short-, and intermediate-term aggregate assessments were included in this risk 

assessment. An aggregate cancer risk assessment was not performed because sulfentrazone is 

not considered to be a carcinogen. Acute and chronic aggregate risks are made up only of 

dietary sources; therefore, the exposure estimates provided in the dietary exposure analysis 

represent acute and chronic aggregate exposure, respectively. Short- and intermediate-term 

aggregate risks are made up of dietary and non-dietary sources of exposure. Since sulfentrazone

is used on turf, residential handler and post-application exposures are expected. Short-term 

exposures exist for adults and children from the registered turf application use. In addition, 

intermediate-term exposures exist for children from incidental soil ingestion. The LOCs for oral 

exposure (MOEs <100) and inhalation exposure (MOEs <1000) are different; therefore, a total 

ARI approach was used to aggregate adult oral, dermal, and inhalation exposures. For children, 

aggregate MOEs were calculated for dermal and oral exposures. The aggregate short- and 

intermediate-term ARIs are >1 for adults and the aggregate MOEs are >100 for children; 

therefore, aggregate exposures to sulfentrazone are not of concern to HED. 

The occupational handler and post-application assessments were completed assuming the 

maximum label application rate. The proposed labels allow for application via aerial equipment, 

groundboom equipment, chemigation equipment, or impregnated onto dry bulk fertilizer. Based 

on the proposed use pattern, the duration of exposure is expected to be short-term (1 to 30 days). 

Intermediate-term exposures are less likely; however, the short- and intermediate-term PODs are 

the same. Therefore, short-term estimated risk estimates are protective of intermediate-term 

exposures. Long-term exposures (greater than 6 months) are not anticipated based on the 

proposed use pattern. The sulfentrazone product labels direct mixers, loaders, applicators and 

other handlers to a wear a long-sleeved shirt and long pants, chemical-resistant gloves, and shoes 

plus socks. Several revisions are required for the proposed labels (e.g., additional personal 

protective equipment; see Section 2.3.2) to ensure that exposure and risk estimates are not of 

concern. 

Establishment of the tolerances recommended in Table 2.2.3 pose no specific concerns for 

environmental justice. This risk assessment relies in part on data from studies in which adult 

human subjects were intentionally exposed to a pesticide or other chemical. Additional details 

regarding this can be found in Appendix D. 

2.0 HED Recommendations

2.1 Data Deficiencies/Conditions of Registration

Pending resolution of the deficiencies outlined below, there are no other residue chemistry, 

toxicology, occupational, or residential data deficiencies that would preclude establishing 

permanent tolerances, as identified in Section 2.2.3. 
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870.3465 28-day Inhalation Study

The Hazard and Science Policy Council (HASPOC) concluded, based on a weight-ofevidence (WOE) approach, that a 28-day inhalation toxicity study is required. It is 

recommended that the registrant submit an inhalation study protocol for Agency review prior 

to conducting the study.

860.1200 Directions for Use

As a ruminant feeding study and additional clover residue data are required to support 

use on nongrass animal feeds crop group 18, these proposed uses should be removed 

from the labels, as described in Sections 2.2.4 and 2.3.1.

The labels should be updated for the following scenarios because additional PPE 

(beyond what is currently on the labels) is required to reach MOEs that are not of 

concern: (1) mixing/loading DFs for chemigation and groundboom applications requires 

the addition of gloves and a PF5 respirator; (2) mixing/loading/applying liquids for soildirected applications with mechanically-pressurized handgun requires the addition of 

gloves and a PF5 respirator; and (3) mixing/loading DFs for aerial application requires 

the addition of gloves and a PF10 respirator.

For the dry bulk fertilizer applications, mixing/loading DFs for commercial 

impregnation of dry bulk fertilizers results in risk estimates of concern using surrogate 

closed mixing/loading exposure data and assuming 960 tons treated daily. Chemicalspecific use data could be submitted to refine the assessment.

860.1550 Proposed Tolerances

A summary of the recommended tolerance levels along with recommendations for 

commodity definitions are presented in Section 2.2.3. The petitioner is required to 

submit a revised Section F to reflect the recommendations in Section 2.2.3.

860.1650 Submittal of Analytical Reference Standards

The standards for sulfentrazone and DMS will soon expire (10/1/2012 and 5/1/2012, 

respectively). The registrant should either recertify the lot in the repository and send an 

updated certificate of analysis (COA), or submit new standards (different lot #) if the 

previous lots will not be recertified. If new standards are being submitted, they should 

be sent to the Analytical Chemistry Lab, which is located at Fort Meade, to the attention 

of either Theresa Cole or Thuy Nygen at the following address:

USEPA

National Pesticide Standards Repository/Analytical Chemistry Branch/OPP

701 Mapes Road

Fort George G. Meade, MD 20755-5350

(Note that the mail will be returned if the extended zip code is not used.)
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2.2 Tolerance Considerations

2.2.1 Enforcement Analytical Method

There is an adequate residue analytical method for the purposes of tolerance enforcement. A gas

chromatography (GC) method for the determination of sulfentrazone and its metabolites DMS and 

HMS was submitted with a petition for a sulfentrazone tolerance for residues in/on soybeans (PP# 

4F04407). A petition method validation (PMV) was successfully completed by the Agency’s 

Analytical Chemistry Laboratory (ACL). The limit of quantitation (LOQ) and limit of detection 

(LOD) were determined to be 0.05 ppm and 0.005-0.025 ppm, respectively. The method has been 

forwarded to the Food and Drug Administration (FDA) for inclusion in the Pesticide Analytical 

Methods Vol. II (PAM II).

The data requirements for multiresidue methods (MRMs) are fulfilled. The FDA MRMs are not 

suitable as enforcement methods since sulfentrazone residues of concern were not successfully 

recovered by the FDA MRMs.

Samples of raw agricultural and processed commodities were analyzed for residues of 

sulfentrazone and its metabolites DMS and HMS using a liquid chromatograph equipped with 

tandem mass spectrometers (LC/MS/MS) method. The validated LOQ was 0.025-0.05 ppm for 

each analyte. These methods are adequate for data collection based on acceptable method 

validation and concurrent recovery data.

2.2.2 International Harmonization

With the exception of sunflower seed (Canada only), no Codex, Canadian, or Mexican maximum 

residue limits (MRLs) have been established for sulfentrazone on the subject crops. The 

Canadian residue definition and the MRL level for sunflower seed are the same as the U.S. 

recommended tolerances. Therefore, harmonization of MRLs and U.S. tolerances is not an issue 

at this time.

2.2.3 Recommended Tolerances

Table 2.2.3 is a summary of the proposed and HED-recommended tolerances under 40 CFR 

§180.498(a)(2) for “combined residues of the free and conjugated forms of sulfentrazone, 

including its metabolites and degradates, in or on the commodities in the table below. Compliance 

with the tolerance levels specified below is to be determined by measuring only the sum of 

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

triazol-1-yl]phenyl]methanesulfonamide) and its metabolites HMS (N-(2,4-dichloro-5-(4-

(difluoromethyl)-4,5-dihydro-3-hydroxymethyl-5-oxo-1H-1,2,4-triazol-1-

yl)phenyl)methanesulfonamide) and DMS (N-(2,4-dichloro-5-(4-(difluoromethyl)-4,5-dihydro-5-

oxo-1H-1,2,4-triazol-1-yl)phenyl)methanesulfonamide, calculated as the stoichiometric equivalent 

of sulfentrazone in or on the following commodities.” 
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Table 2.2.3. Tolerance Summary for Sulfentrazone.

Commodity Proposed 

Tolerance (ppm)

HEDRecommended 

Tolerance (ppm)

Correct Commodity 

Definition/Comments

Establish under 40 CFR §180.498(a)(2):

Rhubarb 0.2 0.15 -

Turnip (roots) 0.2 0.15 Turnip, roots

Turnip (tops) 0.7 0.60 Turnip, tops

Sunflower subgroup 20B 0.2 0.20 -

Vegetable soybean 0.15 0.15 Vegetable, soybean, succulent

Citrus Fruit Crop Group 10-

10 0.15 0.15 Fruit, citrus, group 10-10

Low Growing Berry Crop 

Group 13-07 0.15 0.15 Berry, low growing, group 13-07

Tree Nut Crop Group 14 0.15 0.15 Nut, tree, group 14

Pistachio 0.15 0.15 -

Alfalfa, forage 5 tbd

Additional residue data and a 

ruminant feeding study are required.

Alfalfa, hay 20 tbd

Alfalfa, seed 3 tbd

Clover, forage 5 tbd

Clover, hay 20 tbd

Clover, seed 3 tbd

Establish under 40 CFR §180.498(c) Tolerances with regional registrations:

Wheat, forage 0.45 0.50 -

Wheat, hay 0.20 0.30 -

Wheat, grain 0.20 0.15 -

Wheat, straw 1.4 1.5 -

Cowpea, succulent 0.15 0.15 -

Bean, lima, succulent 0.15 0.15 -

Remove from 40 CFR §180.498(a)(2):

Sunflower, seed - - -

Strawberry - - -

Bean, lima, succulent - - -

Remove from 40 CFR §180.498(b):

Flax, seed - - -

Strawberry - - -

2.2.4 Revisions to Petitioned-For Tolerances

Based on the proposed uses and the submitted data, HED concluded that crop group tolerances 

were appropriate. The HED-recommended tolerances are based on the submitted field trial data 

and the OECD tolerance calculation procedures. Additional data are required to establish 

tolerances for residues of sulfentrazone in/on the nongrass animal feeds crop group 18; therefore 

HED cannot recommended a tolerance for residues in/on this crop group. 

2.3 Label Recommendations

2.3.1 Recommendations from Residue Reviews

The use directions are adequate to allow HED to assess whether the submitted residue data 

reflect the maximum residues likely to occur. As a ruminant feeding study and additional clover 

residue data are required to support the uses on nongrass animal feeds crop group 18, HED could 
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not recommend tolerances for this crop group; therefore, these proposed uses should be removed 

from the labels. A revised Section B is required.

2.3.2 Recommendations from Occupational Assessment 

For occupational handlers, the combined dermal and inhalation exposure risk estimates are not of 

concern (i.e., ARIs >1) at baseline (i.e., single layer of clothing, no gloves, and no respirator) for 

all scenarios, except the following which require additional PPE (beyond what is currently on the 

labels) to reach MOEs that are not of concern: (1) mixing/loading DFs for chemigation and 

groundboom applications requires the addition of gloves and a PF5 respirator; (2) 

mixing/loading/applying liquids for soil-directed applications with mechanically-pressurized 

handgun requires the addition of gloves and a PF5 respirator; and (3) mixing/loading DFs for 

aerial application requires the addition of gloves and a PF10 respirator.

For the dry bulk fertilizer applications, mixing/loading DFs for commercial impregnation of dry 

bulk fertilizers results in risk estimates of concern using surrogate closed mixing/loading 

exposure data and assuming 960 tons treated daily. The estimate for the amount treated is based 

on use data submitted previously for another chemical and is the best data currently available to 

HED. Chemical-specific use data could be submitted to refine the assessment.

3.0 Introduction

3.1 Chemical Identity

Table 3.1. Nomenclature for Sulfentrazone and its Metabolites.

Chemical structure

Common name Sulfentrazone

Company experimental name F6285; FMC 97285

IUPAC name 2',4'-dichloro-5'-(4-difluoromethyl-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol1-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

CAS registry number 122836-35-5

End-use product (EP) 4 lb/gal FlC formulation (Spartan®4F Herbicide; EPA Reg. No. 279-3220) and 

75% DF formulation (Spartan® Herbicide; EPA Reg. No. 279-3189)

Cl

Cl

HN

SO2CH3

N

N

N

O

CH3

CHF2
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Table 3.1. Nomenclature for Sulfentrazone and its Metabolites.

Chemical structure of DMS 

metabolite

Common name 3-desmethyl sulfentrazone; DMS

Chemical name N-(2,4-dichloro-5-(4-(difluoromethyl)-4,5-dihydro-5-oxo-1H-1,2,4-triazol-1-

yl)phenyl)methanesulfonamide

Chemical structure of HMS 

metabolite

Common name 3-hydroxymethyl sulfentrazone; HMS

Chemical name N-(2,4-dichloro-5-(4-(difluoromethyl)-4,5-dihydro-3-hydroxymethyl-5-oxo-1H1,2,4-triazol-1-yl)phenyl)methanesulfonamide

3.2 Physical/Chemical Characteristics

In general, sulfentrazone is persistent and mobile. It has a 545-day aerobic soil half-life1and an 

average Koc coefficient of 45 mL/g. Additionally, it has a strong potential to leach into 

groundwater, as indicated in four completed small-scale prospective ground-water monitoring 

studies, and to move offsite to surface water. It has a low vapor pressure of 8x10-10 mm Hg. A 

detailed description of the physicochemical properties of sulfentrazone is provided in Appendix 

B. 

3.3 Pesticide Use Pattern

The use directions are adequate to allow HED to assess whether the submitted residue data 

reflect the maximum residues of sulfentrazone likely to occur. As a ruminant feeding study and 

additional clover residue data are required to support the proposed uses on nongrass animal feeds 

crop group 18, HED cannot recommend a tolerance for residues of sulfentrazone in/on crop 

group 18 at this time. Therefore, these proposed uses should be removed from the labels. 

Otherwise, the available field trial data support the proposed use directions. 

A list of the sulfentrazone end-use products relevant to this registration request is presented in 

Table 3.3.1. The proposed crop use directions are summarized in Table 3.3.2. Information 

 

1

90th percentile upper confidence interval of the mean half-life.

Cl

Cl

HN

SO2CH3

N

N

N

O

CHF2

Cl

Cl

HN

SO2CH3

N

N

N

O

CHF2

OH
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regarding rotational crop restrictions is listed in Table 3.3.3. The recommended modifications to 

the labels can be found in Section 2.3.

Table 3.3.1. Summary of Proposed End-Use Products.

Trade Name Reg. 

No.

ai (% of 

formulation)

Formulation 

Type Target Crops Target Pests

Spartan®4F Herbicide 279-

3220

39.6

(4 lb ai/gal)

FlC Rhubarb, Turnips, Sunflower Subgroup 20B, 

Cowpeas, Lima beans, Wheat (Spring), Tree 

Nut Crop Group 14, Pistachio, Low-Growing 

Berry Crop Group 13-07, Citrus Fruit Crop 

Group 10-10, Nongrass Animal Feeds Crop 

Group 18

Broadleaf, 

grass, and 

sedge weeds. Spartan® Herbicide 279-

3189

75 DF

F6285 4F CAL 

Herbicide

279-

3370

39.6 (4 lb 

ai/gal)

FlC Rhubarb, Turnips, Sunflower Subgroup 20B, 

Wheat (Spring), Tree Nut Crop Group 14, 

Pistachio, Low-Growing Berry Crop Group 

13-07, Citrus Fruit Crop Group 10-10, 

Nongrass Animal Feeds Crop Group 18

Spartan® Advance 

Herbicide

279-

3334

5.7

(0.56 lb 

ai/gal)

FlC Tree Nut Crop Group 14, Pistachio, LowGrowing Berry Crop Group 13-07, Citrus Fruit 

Crop Group 10-10, Nongrass Animal Feeds 

Crop Group 18

Spartan® Charge 279-

3337

31.77

(3.15 lb 

ai/gal)

FlC Tree Nut Crop Group 14, Pistachio, LowGrowing Berry Crop Group 13-07, Citrus Fruit 

Crop Group 10-10, Nongrass Animal Feeds 

Crop Group 18

Authority® Assist 279-

3330

33.33

(3.33 lb 

ai/gal)

FlC Nongrass Animal Feeds Crop Group 18

F6482 45DF Herbicide 279-

3340

18 DF Nongrass Animal Feeds Crop Group 18

Table 3.3.2. Summary of Proposed Directions for Use of Sulfentrazone.

App. Timing; Type; and 

Equip.

Formulation 

(EPA Reg. No.)

Application 

Rates

Max. # 

App. per 

Year

Max. 

Yearly 

App. Rate 

Use Directions and Limitations

Rhubarb

Postemergence just prior to 

rhubarb plants breaking 

dormancy (80 ± 5 days 

before harvest)

Aerial, ground, chemigation, 

impregnated onto dry bulk 

fertilizer

Spartan 

Herbicide

(279-3189)

0.25 lb ai/A 1 0.25 lb ai/A Personal-protective equipment 

(PPE) = Long-sleeved (LS) shirt, 

long pants, chemical-resistant 

gloves, shoes plus socks.

Restricted-entry interval (REI) = 

12 hours.

*General use directions: Aerial: 

min of 5 gallons per acre (GPA); 

Ground: min of 10 GPA.

*Crop-specific directions: 

recommend applying minimum of 

10 GPA.

Dry bulk fertilizer: min of 200 

lb/A.

F6285 4F CAL 

Herbicide

(279-3370)

0.25 lb ai/A 0.25 lb ai/A

Spartan 4F 

Herbicide

(279-3320)

0.25 lb ai/A 0.25 lb ai/A

Turnip Roots and Tops

Postemergence at 46-60 days 

preharvest

Aerial, ground, chemigation, 

impregnated onto dry bulk 

fertilizer

Spartan 

Herbicide

(279-3189)

0.25 lb ai/A 1 0.25 lb ai/A PPE = LS shirt, long pants, 

chemical-resistant gloves, shoes 

plus socks.

REI = 12 hours.

*General use directions: Aerial: 

min of 5 GPA; Ground: min of 

10 GPA.

*Crop-specific directions: 

F6285 4F CAL 

Herbicide

(279-3370)

0.25 lb ai/A 0.25 lb ai/A

Spartan 4F 

Herbicide

0.25 lb ai/A 0.25 lb ai/A
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Table 3.3.2. Summary of Proposed Directions for Use of Sulfentrazone.

App. Timing; Type; and 

Equip.

Formulation 

(EPA Reg. No.)

Application 

Rates

Max. # 

App. per 

Year

Max. 

Yearly 

App. Rate 

Use Directions and Limitations

(279-3320) recommend applying in 10-40 

GPA.

Dry bulk fertilizer: min of 200 

lb/A.

Sunflower Subgroup 20B

(Calendula; castor oil plant; Chinese tallowtree; euphorbia; evening primrose; jojoba; niger seed; rose hip; safflower; 

stokes aster; sunflower; tallowwood; tea oil plant; vernonia; cultivars, varieties, and/or hybrids of these)

Fall, early spring preplant, 

preemergence, preplant 

incorporated

Aerial, ground, chemigation, 

impregnated onto dry bulk 

fertilizer

Spartan 

Herbicide

(279-3189)

0.09 - 0.25 

lb ai/A

Up to 3 0.25 lb ai/A PPE = LS shirt, long pants, 

chemical-resistant gloves, shoes 

plus socks.

REI = 12 hours.

Aerial: min of 5 GPA.

Ground: min of 10 GPA.

No retreatment interval (RTI) 

specified.

Dry bulk fertilizer: min of 200 

lb/A.

F6285 4F CAL 

Herbicide

(279-3370)

0.09 - 0.25 

lb ai/A

0.25 lb ai/A

Spartan 4F 

Herbicide

(279-3320)

0.09 - 0.25 

lb ai/A

0.25 lb ai/A

Cowpeas, Succulent (Tennessee only)

Preemergence

Ground

Spartan 

Herbicide

(279-3189)

0.07 - 0.188 

lb ai/A

Up to 3 0.188 lb 

ai/A

PPE = LS shirt, long pants, 

chemical-resistant gloves, shoes 

plus socks.

REI = 12 hours.

Ground: min of 10 GPA.

No RTI specified.

Dry bulk fertilizer: min of 200 

lb/A. 

Spartan 4F 

Herbicide

(279-3320)

0.07 - 0.188 

lb ai/A

0.188 lb 

ai/A

Lima bean, Succulent (Tennessee only)

Preemergence

Ground

Spartan 

Herbicide

(279-3189)

0.07 - 0.188 

lb ai/A

Up to 3 0.188 lb 

ai/A

PPE = LS shirt, long pants, 

chemical-resistant gloves, shoes 

plus socks.

REI = 12 hours.

Ground: min of 10 GPA.

No RTI specified.

Dry bulk fertilizer: min of 200 

lb/A. 

Spartan 4F 

Herbicide

(279-3320)

0.07 - 0.188 

lb ai/A

0.188 lb 

ai/A

Wheat (Spring) (Pacific Northwest only)

Preplant or preemergent at 

40-60 days before forage 

cutting and 120 days before 

grain harvest

Aerial, ground, chemigation, 

impregnated onto dry bulk 

fertilizer

Spartan 

Herbicide

(279-3189)

0.188 lb 

ai/A

1 0.188 lb 

ai/A

PPE = LS shirt, long pants, 

chemical-resistant gloves, shoes 

plus socks.

REI = 12 hours.

*General use directions: Aerial: 

min of 5 GPA; Ground: min of 

10 GPA.

*Crop-specific directions: 

recommend applying in 10-40 

GPA.

F6285 4F CAL 

Herbicide

(279-3370)

0.188 lb 

ai/A

0.188 lb 

ai/A

Spartan 4F 

Herbicide

(279-3320)

0.188 lb 

ai/A

0.188 lb 

ai/A

Tree Nut Crop Group 14 and Pistachio

(Almond; beech nut; Brazil nut; butternut; cashew; chestnut; chinquapin; filbert (hazelnut); hickory nut; macadamia nut; 

pecan; walnut, black and English)

Apply as soil application to 

orchard floors or as uniform 

band application directed 

towards base of the trunk of 

trees

Ground, impregnated onto 

dry bulk fertilizer

Spartan 4F 

Herbicide

(279-3320)

0.125 -

0.375 lb 

ai/A

Up to 3 0.375 lb 

ai/A

PPE = LS shirt, long pants, 

chemical-resistant gloves, and 

shoes plus socks.

REI = 12 hours.

*General use directions: Aerial: 

min of 5 GPA; Ground: min of 

10 GPA.

PHI = 3 days.

RTI = 60 days.

Apply using ground equipment 

F6285 4F CAL 

Herbicide

(279-3370)

Spartan Advance 

Herbicide

(279-3334)a

0.129 -

0.375 lb 

ai/A

0.375 lb 

ai/A

Spartan 0.125 - 0.375 lb 
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Table 3.3.2. Summary of Proposed Directions for Use of Sulfentrazone.

App. Timing; Type; and 

Equip.

Formulation 

(EPA Reg. No.)

Application 

Rates

Max. # 

App. per 

Year

Max. 

Yearly 

App. Rate 

Use Directions and Limitations

Herbicide

(279-3189)

0.375 lb 

ai/A

ai/A only; do not use airblast sprayer 

or apply by air.

Avoid direct or indirect spray 

contact with foliage and fruit.

279-3334: Do not apply via 

chemigation.

Spartan Charge

(279-3337)

0.189 -

0.374 lb 

ai/A

Up to 2 0.374 lb 

ai/A

Low-Growing Berry Crop Group 13-07 (includes Grape)b

Apply as soil application to 

orchard floors or as uniform 

band application directed 

towards base of the trunk of 

trees

Ground, impregnated onto 

dry bulk fertilizer

Spartan 4F 

Herbicide

(279-3320)

0.125 -

0.375 lb 

ai/A

Up to 3 0.375 lb 

ai/A

PPE = LS shirt, long pants, 

chemical-resistant gloves, and 

shoes plus socks.

REI = 12 hours.

*General use directions: Aerial: 

min of 5 GPA; Ground: min of 

10 GPA.

PHI = 3 days.

RTI = 60 days.

Apply using ground equipment 

only; do not use airblast sprayer 

or apply by air.

Avoid direct or indirect spray 

contact with foliage and fruit.

279-3334: Do not apply via 

chemigation.

F6285 4F CAL 

Herbicide

(279-3370)

Spartan Advance 

Herbicide

(279-3334)a

0.129 -

0.375 lb 

ai/A

0.375 lb 

ai/A

Spartan 

Herbicide

(279-3189)

0.125 -

0.375 lb 

ai/A

0.375 lb 

ai/A

Spartan Charge

(279-3337)

0.189 -

0.374 lb 

ai/A

Up to 2 0.374 lb 

ai/A

Citrus Fruit Crop Group 10-10c

Apply as soil application to 

orchard floors or as uniform 

band application directed 

towards base of the trunk of 

trees

Ground, impregnated onto 

dry bulk fertilizer

Spartan 4F 

Herbicide

(279-3320)

0.125 -

0.375 lb 

ai/A

Up to 3 0.375 lb 

ai/A

PPE = LS shirt, long pants, 

chemical-resistant gloves, and 

shoes plus socks.

REI = 12 hours.

*General use directions: Aerial: 

min of 5 GPA; Ground: min of 

10 GPA.

PHI = 3 days.

RTI = 60 days.

Apply using ground equipment 

only; do not use airblast sprayer 

or apply by air.

Avoid direct or indirect spray 

contact with foliage and fruit.

279-3334: Do not apply via 

chemigation.

F6285 4F CAL 

Herbicide

(279-3370)

Spartan Advance 

Herbicide

(279-3334)a

0.129 -

0.375 lb 

ai/A

0.375 lb 

ai/A

Spartan 

Herbicide

(279-3189)

0.125 -

0.375 lb 

ai/A

0.375 lb 

ai/A

Spartan Charge

(279-3337)

0.189 -

0.374 lb 

ai/A

Up to 2 0.374 lb 

ai/A

Nongrass Animal Feeds Crop Group 18

(Alfalfa; bean, velvet; clover (Trifolium, Melilotus); kudzu; lespedeza; lupin; sainfoin; trefoil; vetch; vetch, crown; vetch, 

milk)

Dormant Season Soil 

treatment (Fall or Winter 

applications preemergent to 

weeds)

Between cutting in-season 

application (spring/summer 

preemergent to weeds) –

applied between cuttings as 

soon as possible after 

removal of previous hay crop 

and prior to significant regrowth (<6 inches) on 

Spartan 4F 

Herbicide

(279-3320)

0.09 - 0.375 

lb ai/A

Up to 4 0.375 lb 

ai/A

PPE = LS shirt, long pants, 

chemical-resistant gloves, and 

shoes plus socks.

REI = 12 hours

*General use directions: Aerial: 

min of 5 GPA; Ground: min of 

10 GPA.

PHI = forage and hay may be 

harvested or grazed 21 days after 

application, and crop grown for 

seed may be harvested as early as 

41 days after application. 

F6285 4F CAL 

Herbicide

(279-3370)

Authority 

Assistd

(279-3330)

0.09 - 0.375 

lb ai/A

0.375 lb 

ai/A

Spartan Advance 

Herbicide

(279-3334)a

lb ai/A 0.372 lb 

ai/A

Spartan 0.09 - 0.375 0.375 lb 
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Table 3.3.2. Summary of Proposed Directions for Use of Sulfentrazone.

App. Timing; Type; and 

Equip.

Formulation 

(EPA Reg. No.)

Application 

Rates

Max. # 

App. per 

Year

Max. 

Yearly 

App. Rate 

Use Directions and Limitations

steams and crowns.

Aerial, ground, chemigation, 

impregnated onto dry bulk 

fertilizer 

Herbicide

(279-3189)

lb ai/A ai/A 279-3334: Alfalfa only. PHI = 

forage and hay may be harvested 

or grazed 21 days after 

application.

279-3330: Do not apply via 

chemigation. PHI = forage and 

hay may be harvested or grazed 

30 days after application, and 

crop grown for seed may be 

harvested as early as 41 days after 

application. 

Spartan Charge

(279-3337)

0.09 - 0.359 

lb ai/A

0.359 lb 

ai/A

May be applied on dormant 

alfalfa and sainfoin stubble 

as a soil treatment prior to 

weed emergence.

Do not apply after growth 

begins in spring or before 

growth ceases in fall

Aerial, Groundboom

F6482 45DF 

Herbicide

(279-3340)e

0.09 - 0.375 

lb ai/A

Up to 4 0.375 lb 

ai/A

**Alfalfa and Sainfoin only.

Do not apply via chemigation.

PHI = forage may be harvested or 

grazed 28 days after application.

a. Multiple active ingredient: co-formulated with glyphosate isopropylamine salt.

b. Amur river grape; aronia berry; bayberry; bearberry; bilberry; blackberry (including Andean blackberry, arctic blackberry, 

bingleberry, black satin berry, boysenberry, brombeere, California blackberry, Chesterberry, Cherokee blackberry, Cheyenne 

blackberry, common blackberry, coryberry, darrowberry, dewberry, Dirksen thornless berry, evergreen blackberry, Himalayaberry, 

hullberry, lavacaberry, loganberry, lowberry, Lucretiaberry, mammoth blackberry, marionberry, mora, mures deronce, nectarberry, 

Northern dewberry, olallieberry, Orgeon evergreen berry, phenomenalberry, rangeberry, ravenberry, rossberry, Shawnee blackberry, 

Southern dewberry, tayberry, youngberry, zarzamora, and cultivars, varieties and/or hybrids of these); blueberry, highbush; blueberry, 

lowbush; buffalo currant; buffaloberry; che; Chilean guava; chokecherry; cloudberry; cranberry; cranberry, highbush; currant, black; 

currant, red; elderberry; European barberry; gooseberry; grape; honeysuckle, edible; huckleberry; jostaberry; Juneberry (Saskatoon 

berry); kiwifruit, fuzzy; kiwifruit, hardy; lingonberry; maypop; mountain pepper berries; mulberry; muntries; native currant; 

partridgeberry; phalsa; pincherry; raspberry, black and red; riberry; salal; schisandra berry; sea buckthorn; serviceberry; strawberry; 

wild raspberry; cultivars, varieties, and/or hybrids of these.

c. Australian desert lime; Australian finger-lime; Australian round lime; Brown River finger lime; calamondin; citron; citrus hybrids; 

grapefruit; Japanese summer grapefruit; kumquat; lemon; lime; Mediterranean mandarin; mount white lime; New Guinea wild lime; 

orange, sour; orange, sweet; pummelo; Russell River lime; satsuma mandarin; sweet lime; tachibana orange; Tahiti lime; tangelo; 

tangerine (mandarin); tangor; trifoliate orange; uniq fruit; cultivars, varieties, and/or hybrids of these.

d. Multiple active ingredient product: co-formulated with imazethapyr (6.67% ai).

e. Multiple active ingredient product: co-formulated with metribuzin (55% ai).

Table 3.3.3. Plantback Intervals for Use of Sulfentrazone.

Rotational Crop1Plantback Interval (months)

Alfalfa 12

Barley 4

Cabbage Anytime

Canola 24

Cereal Grains (Buckwheat, Oats, Pearl Millet, Proso 

Millet, Teosinte, Wild Rice)

12

Corn, Field 10

Corn, Pop 18

Corn, Sweet 18

Cotton 18

Dry Shell Peas and Beans Anytime

Horseradish Anytime

Limas Anytime

Mint Anytime

Peanuts Anytime
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Table 3.3.3. Plantback Intervals for Use of Sulfentrazone.

Rotational Crop1Plantback Interval (months)

Potatoes Anytime

Rice 10

Rye 4

Sorghum 102

Soybean Anytime

Sugar Beets 36

Sugarcane Anytime

Sunflowers Anytime

Sweet Potatoes 12

Triticale 4

Tobacco Anytime

Turf Anytime

Wheat 4

1 For all other crops not listed, the rotation interval is a minimum of 12 months.

2 Sorghum – 18-month rotation for rates above 8.0 oz/A.

3.4 Anticipated Exposure Pathways

RD has requested that HED perform an assessment of human-health risk to support the proposed 

new uses of sulfentrazone. Humans may be exposed to sulfentrazone through the consumption 

of food and drinking water containing sulfentrazone residues. Residential uses of sulfentrazone 

may result in inhalation and dermal exposures for adults, and dermal and incidental oral 

exposures for children. In an occupational setting, applicators may be exposed while handling 

sulfentrazone prior to application, as well as during application. There is also a potential for 

post-application exposure for workers re-entering treated fields. 

Risk assessments have been previously prepared for the existing uses of sulfentrazone. This risk 

assessment considers the proposed new uses of sulfentrazone as well as existing uses, 

particularly for the dietary exposure assessment. The aggregate assessment considers dietary 

(food plus drinking water) and residential exposures. 

3.5 Consideration of Environmental Justice

Potential areas of environmental justice concerns, to the extent possible, were considered in this 

human health risk assessment, in accordance with U.S. Executive Order 12898, "Federal Actions 

to Address Environmental Justice in Minority Populations and Low-Income Populations," 

(http://www.hss.energy.gov/nuclearsafety/env/guidance/justice/eo12898.pdf. As a part of every 

pesticide risk assessment, OPP considers a large variety of consumer subgroups according to 

well-established procedures. In line with OPP policy, HED estimates risks to population 

subgroups from pesticide exposures that are based on patterns of that subgroup’s food and water 

consumption, and activities in and around the home that involve pesticide use in a residential 

setting. Extensive data on food consumption patterns are compiled by the USDA under the 

Continuing Survey of Food Intake by Individuals (CSFII) and are used in pesticide risk 

assessments for all registered food uses of a pesticide. These data are analyzed and categorized 

by subgroups based on age, season of the year, ethnic group, and region of the country. 

Additionally, OPP is able to assess dietary exposure to smaller, specialized subgroups and 

exposure assessments are performed when conditions or circumstances warrant. Whenever 

appropriate, non-dietary exposures based on home use of pesticide products and associated risks 
Sulfentrazone Human-Health Risk Assessment DP No. 389082

Page 18 of 54

for adult applicators and for toddlers, youths, and adults entering or playing on treated areas 

postapplication are evaluated. Further considerations are currently in development as OPP has 

committed resources and expertise to the development of specialized software and models that 

consider exposure to bystanders and farm workers as well as lifestyle and traditional dietary 

patterns among specific subgroups.

4.0 Hazard Characterization and Dose-Response Assessment

Sulfentrazone belongs to a class of herbicides that inhibit PPO in target organisms, ultimately 

resulting in disruption of chlorophyll biosynthesis. In mammals, PPO is also an important 

enzyme in heme biosynthesis and its inhibition can lead to toxic effects associated with 

disruption of heme utilization (e.g., red blood cells). Some of the toxicities reported for 

sulfentrazone in mammals are consistent with a mode of action involving inhibition of PPO.

4.1 Toxicology Studies Available for Analysis

The toxicological database for sulfentrazone is adequate for evaluation. In the last risk 

assessment (K. Lowe et al., 22-DEC-2010; D364882), the only toxicity database deficiency 

noted was an immunotoxicity study, as specified in the revised 40 CFR Part 158 requirements. 

Since then, an acceptable (pending finalization) 28-day rat immunotoxicity study has been 

submitted to the Agency. In addition, the HED HASPOC met on February 16, 2012 (TXR# 

0050684) to evaluate the need for a repeated inhalation exposure study with sulfentrazone and 

concluded, based on a WOE approach, that a 28-day rat inhalation study is now required. 

4.2 Absorption, Distribution, Metabolism, & Excretion (ADME)

In radiolabel-based studies in the rat, sulfentrazone was well absorbed via the oral route of 

administration as indicated by the excretion of nearly all radioactivity in urine by 72 hours postdosing. There was no indication of accumulation; only the carcass, liver, and bone showed 

detectable levels of radioactivity (<0.5% of the administered) at 72 hours post-dosing. The 

pooled urinary radioactivity consisted almost entirely of a hydroxy methyl metabolite (HMS); 

the parent chemical was not detected in urine and found only at very low levels in feces. There 

were no apparent sex-dependent differences in ADME behavior noted.

4.2.1 Dermal Absorption

There are no dermal absorption studies available for sulfentrazone; however, there is a rat 28-day 

dermal toxicity study and a dermal route-specific rat prenatal developmental toxicity study that 

can be used to assess risk via the dermal route of exposure.

4.3 Toxicological Effects

Based on the results of acute toxicity studies in the rat, sulfentrazone was classified as Category 

III (Category IV being the lowest category) for acute toxicity via the oral, dermal, and inhalation 

routes of exposure. It was a mild eye irritant (Category III), but not a dermal irritant or 

sensitizer. 

Subchronic and chronic toxicity studies in rats, mice, and dogs identified the hematopoietic 
Sulfentrazone Human-Health Risk Assessment DP No. 389082

Page 19 of 54

system as the target of sulfentrazone. Sulfentrazone inhibits the enzyme PPO in target plants and 

the results of subchronic and chronic toxicity studies in mammalian systems are consistent with 

this mode of action, given that PPO is an important enzyme in the heme synthetic pathway in 

mammals. Disruption of heme biosynthesis was indicated by signs of anemia [decreases in 

hematocrit, hemoglobin, and mean cell volume (MCV)] in mice, rats, and dogs at comparable 

dose levels from short- through long-term exposure without increasing much in severity. 

Sulfentrazone caused developmental effects when administered via the oral (rats and rabbits) and 

dermal (rat) routes of exposure. Developmental effects in rats and rabbits consisted of 

reductions in the number of implantations (rats only), increase in early resorptions (rats and 

rabbits), and reduction in live fetuses per litter (rats and rabbits). Surviving rat fetuses exhibited 

reduced/delayed skeletal ossifications, and decreased fetal body weights were observed in both 

an oral and a dermal developmental toxicity study in rats at doses that were not maternally toxic. 

In contrast with the rat studies, developmental effects in rabbits were observed at a maternally 

toxic dose, where clinical signs of toxicity included hematuria (red blood cells in urine), 

abortions, and decreased body-weight gains. In the 2-generation reproductive toxicity study in 

rats, developmental effects included an increased duration of gestation, reduced prenatal viability 

(fetal and litter), reduced litter size, and an increased number of stillborn pups. Pup body-weight 

deficits, along with reduced pup and litter postnatal survival, were also observed. All of the 

developmental effects were reported in the presence of mild maternal toxicity (slightly decreased 

body-weight gain, particularly in F1 females).

In an acute neurotoxicity (ACN) study in rats, an increased incidence of clinical signs of toxicity 

(staggered gait, splayed hind limbs, and abdominal gripping), changes in functional-observation 

battery (FOB) parameters, and decreased motor activity were observed at a high dose level (750 

mg/kg bw). Complete recovery was observed by day 14, and there was no evidence of 

neuropathology. In a rat subchronic neurotoxicity (SCN) study, clinical signs of toxicity, 

increased motor activity, and/or decreased body weights, body-weight gain, and food 

consumption were also observed with no evidence of neuropathology. 

A published, non-guideline developmental toxicity study in the rat [DeCastro VL, Destefani CR, 

Diniz C, Poli P., 2007. Evaluation of neurodevelopmental effects on rats exposed prenatally to 

sulfentrazone. Neurotoxicology 28(6):1249-59] did not demonstrate conclusively developmental 

neurotoxicity and contains several shortcomings that limit its use for regulatory purposes 

including the lack of a NOAEL. The reported effects involving measures of physical and reflex 

development are likely secondary effects reflective of the poor general state of the offspring as 

reported in the rat 2-generation reproductive toxicity study at similar dose levels but with a welldefined NOAEL [more information on the review of this study can be found in the last risk 

assessment (K. Lowe et al., 22-DEC-2010; D364882) and Memo, C. Rodriguez, 19-DEC-2011, 

D389975]. 

No systemic toxicity was seen via the dermal route up to the limit dose (1,000 mg/kg/day) in a 

28-day dermal toxicity study in rabbits. 

Preliminary review of a recently submitted 28-day rat immunotoxicity study suggests that 

sulfentrazone does not directly target the immune system; and, there is no evidence of 

immunotoxicity in the rest of the toxicity database for sulfentrazone.
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Carcinogenicity studies in rats and mice showed no evidence of increased incidence of tumor 

formation due to treatment with sulfentrazone, and the Cancer Assessment Review Committee 

(CARC) previously classified sulfentrazone as “not likely to be carcinogenic to humans” in 

accordance with EPA proposed Guidelines for Carcinogenic Risk Assessment (April 10, 1996). 

The available mutagenicity studies indicate that sulfentrazone is weakly clastogenic in the in

vitro mouse lymphoma assay in the absence of S9 activation. There is no evidence that 

sulfentrazone is mutagenic in bacterial cells or clastogenic in male or female mice in vivo.

4.4 Safety Factor for Infants and Children (FQPA Safety Factor)

The RAB1 risk assessment team recommends that the FQPA SF be reduced to 1X for all 

exposure scenarios, except for the inhalation exposure scenarios for which the FQPA SF is being 

retained at 10X due to the lack of an appropriate inhalation toxicity study. The rationale is 

provided below.

4.4.1 Completeness of the Toxicology Database

The existing toxicology database for sulfentrazone is adequate for FQPA evaluation. The 

following acceptable studies are available for FQPA consideration:

Developmental toxicity studies in rats and rabbits

Two-generation reproduction study in rats 

Acute and subchronic neurotoxicity studies in rats

The developing nervous system is not considered a selective target of sulfentrazone’s toxicity. 

Therefore, the classification of the published, non-guideline rat developmental toxicity study by 

DeCastro et al., 2007 (mentioned above) as unacceptable has no impact on the completeness of 

the toxicity database for FQPA consideration.

In the case of inhalation exposures, the HASPOC met on February 16, 2012 to evaluate the need 

for a 28-day inhalation study in rats. The HASPOC concluded, based on a WOE approach, that a 

28-day inhalation study in rats is required to adequately assess short- and intermediate-term 

exposure scenarios based on the currently registered labels and use pattern. As a result, an 

FQPA SF of 10X is being retained for inhalation exposure scenarios due to the lack of an 

appropriate 28-day rat inhalation toxicity study. 

4.4.2 Evidence of Neurotoxicity

There is no concern for neurotoxicity with sulfentrazone. Evidence of neurotoxicity from both 

ACN and SCN studies consisted of clinical signs in the absence of neuropathology. In addition, 

both ACN and SCN studies in the rat attained clear NOAELs. There is no evidence in the 

toxicity database that the developmental nervous system is a selective target of sulfentrazone’s 

toxicity and the published, non-guideline rat developmental toxicity study by DeCastro et al., 

2007 has been classified, due to several shortcomings, as unacceptable for use in regulatory 

purposes.
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4.4.3 Evidence of Sensitivity/Susceptibility in the Developing or Young Animal

There was evidence for increased (quantitative) susceptibility following oral and dermal 

exposures in the developmental toxicity studies in rats. There was no evidence of increased 

susceptibility in rabbits; developmental effects were seen in the presence of maternal toxicity. In 

the rat 2-generation reproduction study, offspring toxicity was seen in the presence of 

parental/systemic toxicity. Although developmental toxicity was observed at lower doses than 

maternal toxicity in both oral and dermal developmental toxicity studies in rat, the concern is low 

based on the following considerations: 1) the toxicology database for assessing pre- and postnatal susceptibility is complete; 2) there are clear NOAELs and LOAELs for the developmental 

effects observed via both the oral and dermal routes; 3) the PODs used for assessing dietary and 

non-dietary (dermal and inhalation) exposure risks are based on developmental and/or offspring 

toxicity; and 4) there are no residual uncertainties for pre-and/or post-natal toxicity. 

4.4.4 Residual Uncertainty in the Exposure Database

There are no residual uncertainties in the exposure database. The dietary and residential 

exposure analyses are conservative in nature. The dietary exposure assessment used tolerancelevel residues and assumed 100% CT. The residential exposure assessment uses the 2012 

Residential SOPs and is considered health-protective. The residential assessment includes an 

FQPA SF of 10X for inhalation exposures to account for the uncertainty associated with the lack 

of an appropriate inhalation toxicity study. 

4.5 Toxicity Endpoints and Point of Departure Selections

4.5.1 Dose-Response Assessment

Table 4.5.4 summarizes the toxicological doses and endpoints selected for residential 

dietary/non-dietary and occupational risk assessment. The rationale for any changes is provided 

below and the updated endpoints are included in Table 4.5.4. The updated endpoints are 

protective of sulfentrazone’s developmental toxicity, which was the critical effect in the database 

and observed via both the oral and dermal routes of exposure.

Acute Dietary Endpoint (Females 13 - 49 years old): This acute dietary endpoint is based on 

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

increased number of stillborn pups, reduced postnatal survival (pups and litter), and pup bodyweight deficits throughout lactation in both generations of offspring observed in the 2-generation 

reproductive toxicity study in rats. The developmental effects were reported in the presence of 

mild maternal toxicity (slightly decreased body-weight gain, particularly in F1 females). It has 

been HED’s practice to consider various forms of developmental toxicity, such as the such as 

reduced prenatal viability, reduced litter size, and increased number of stillborn pups as singledose effects and, therefore, relevant for the acute dietary (females aged 13-49) exposure scenario 

in order to protect against potential exposure of pregnant females. It should be noted that the 

fetal body weight deficits and retardation in skeletal development (including decreased numbers 

of caudal vertebral and metacarpal ossification sites) reported in the oral rat prenatal 

developmental toxicity study were also evaluated for this acute dietary endpoint. However, it 

was concluded that such effects are unlikely due to a single dose event and are more appropriate 
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for a repeated- exposure scenario. Furthermore, EPA has not traditionally considered delays in 

ossification (and related fetal body weight deficits) to be single dose effects. The conventional 

100-fold factor (10X inter-, and 10X intra-species) was applied to the NOAEL (14 mg/kg 

bw/day). The FQPA SF was not retained for this exposure scenario since the toxicology 

database is complete for pre- and/or postnatal susceptibility. Thus, the acute reference dose 

(aRfD) and population-adjusted dose (aPAD) are equivalent at 0.14 mg/kg bw/day.

Acute Dietary Endpoint (General population, including infants and children): This acute 

endpoint is based upon increased incidence of clinical signs, FOB findings, and decreased motor 

activity at the LOAEL of 750 mg/kg bw (NOAEL = 250 mg/kg bw) seen following a single oral 

administration in the acute neurotoxicity study. The FQPA SF was not retained for this exposure 

scenario since the toxicology database is complete for pre- and/or postnatal susceptibility. The 

aRfD and aPAD are equivalent at 2.5 mg/kg bw/day.

Chronic Dietary Endpoint (All populations): The chronic dietary endpoint is based on increased 

gestation duration, reduced pre-/postnatal litter and pup survival, and pup body-weight deficits 

throughout lactation in both generations of offspring observed at the LOAEL of 33 and 40 mg/kg 

bw in males and females, respectively (lowest NOAEL = 14 mg/kg/day for males) in the rat 2-

generation reproductive toxicity study. This study is based on the most sensitive endpoint: 

developmental toxicity. The FQPA SF was not retained for this exposure scenario since the 

toxicology database is complete for pre- and/or postnatal susceptibility. The chronic reference 

dose (cRfD) and population-adjusted dose (cPAD) are equivalent at 0.14 mg/kg bw/day.

Incidental Oral Endpoint (Short- and intermediate-term): This endpoint is based on offspring 

toxicity observed in the rat 2-generation reproductive toxicity study in the form of reduced pre-

/postnatal litter and pup survival, and pup body-weight deficits throughout lactation in both 

generations of offspring observed at the LOAEL of 33 and 40 mg/kg bw in males and females, 

respectively (lowest NOAEL = 14 mg/kg/day for males). The effects seen in the offspring are 

appropriate for the population of concern (infants and children) and durations (short- and 

intermediate-term) of exposure. The LOC for incidental oral risk estimates is for MOEs less 

than 100, which includes the 10X inter- and 10X-intra-species factor is adequate for this 

exposure scenario. The FQPA SF was not retained since the toxicology database is complete for 

pre-and/or post-natal susceptibility and there are no residual uncertainties.

Dermal Endpoints (Short- and intermediate-term): This endpoint is based on developmental 

toxicity observed in a dermal developmental toxicity study in rats. This endpoint is appropriate 

since the developmental effects were seen after repeated exposure via the route of exposure of 

concern – dermal. The LOC for occupational and non-occupational dermal risk estimates is for 

MOEs less than 100, which includes the 10X inter-and 10X intra-species factors. The FQPA SF 

was not retained since the toxicology database is complete for pre- and/or postnatal susceptibility 

and there are no residual uncertainties.

Inhalation Endpoints (Short- and intermediate-term): The HED HASPOC met on February 16, 

2012 (TXR# 0050684) to evaluate the need for a repeated inhalation exposure study with 

sulfentrazone and concluded, based on a WOE approach, that a 28-day rat inhalation study is 

now required. In the absence of such study, the rat oral prenatal developmental toxicity study 

with an assumed 100% absorption via the inhalation route will be used along with an FQPA SF 

of 10X. The rat oral prenatal developmental toxicity study is considered protective of 
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developmental toxicity which is the most critical effect associated with sulfentrazone. The 

endpoint is based on decreased mean fetal weights and retardation in skeletal development 

evidenced by an increased number of litters with any variation and by decreased number of 

caudal vertebral and metacarpal ossification sites. The LOC for occupational and nonoccupational inhalation risk estimates are for MOEs less than 1000. This value includes a 10X

inter-species factor, a 10X intra-species factor, and an additional 10X UFDB to protect for the 

uncertainty from the oral to inhalation route-to-route extrapolation. 

4.5.2 Recommendation for Combining Routes of Exposures for Risk Assessment

The Agency must consider risks from individual routes of exposure (oral, dermal, and inhalation) 

and perform an aggregate risk assessment if a common toxicity endpoint is established across 

different routes of exposure. The developmental effects (fetal body-weight deficits and skeletal 

effects) observed in the dermal and oral rat developmental toxicity study can be aggregated for 

the dermal and inhalation endpoints. 

4.5.3 Cancer Classification and Risk Assessment Recommendation

The CARC has classified sulfentrazone as “not likely to be carcinogenic” to humans (TXR #: 

011910) in accordance with EPA proposed Guidelines for Carcinogenic Risk Assessment (April 

10, 1996).

4.5.4 Summary of Points of Departure and Toxicity Endpoints Used in Human-Health 

Risk Assessment

Table 4.5.4. Summary of Toxicological Doses and Endpoints for Sulfentrazone for Use in Residential and 

Occupational Human Health Risk Assessment.

Exposure Scenario POD Uncertainty/

FQPA SFs

RfD, PAD, 

LOC for 

Risk 

Assessment

Study and Toxicological Effects

Acute Dietary

(Females 13-49)

NOAEL = 14 

mg/kg/day

UFA = 10X

UFH = 10X

FQPA SF = 1X

aRfD = 

aPAD = 0.14 

mg/kg/day

2-Gen Reproductive Toxicity Study - Rat

Offspring Toxicity LOAEL= 33 (M) and 40 (F) 

mg/kg/day based on reduced prenatal viability 

(fetal & litter), reduced litter size, increased no. of 

stillborn pups, reduced pup and litter postnatal 

survival, and decreased pup body weights 

throughout lactation.

Acute Dietary

(General population

including infants

and children)

NOAEL = 

250

mg/kg/day

UFA = 10X

UFH = 10X

FQPA SF = 1X

aRfD 

=aPAD = 2.5 

mg/kg/day

Acute Neurotoxicity Study - Rat

LOAEL = 750 mg/kg/day based on increased 

incidence of clinical signs and FOB parameters 

and decreased motor activity.

Chronic Dietary

(all populations)

NOAEL = 14 

mg/kg/day 

UFA = 10X

UFH = 10X

FQPA SF = 1X

cRfD = 

cPAD =

0.14 

mg/kg/day

2-Gen Reproductive Toxicity Study - Rat

Offspring Toxicity LOAEL = 33 (M) and 40 (F) 

mg/kg/day based on reduced prenatal viability 

(fetal & litter), reduced litter size, increased no. of 

stillborn pups, reduced pup and litter postnatal 

survival, and decreased pup body weights 

throughout lactation.

Short- (1-30 days) and 

Intermediate-Term (1-

6 months) Incidental 

Oral 

Offspring

NOAEL = 14 

mg/kg/day

UFA = 10X

UFH = 10X

FQPA SF = 1X

Residential 

LOC for 

MOE = 100

2-Generation Reproduction Study - Rat

Offspring LOAEL = 33 mg/kg/day based on 

decreased pup body weights and reduced 

postnatal survival in both generations.

Short- (1-30 days), 

Intermediate- (1-6 

NOAEL =

100 

UFA = 10X

UFH = 10X

Residential 

LOC for 

Dermal Developmental Study - Rat

LOAEL = 250 mg/kg/day based on decreased 
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Table 4.5.4. Summary of Toxicological Doses and Endpoints for Sulfentrazone for Use in Residential and 

Occupational Human Health Risk Assessment.

Exposure Scenario POD Uncertainty/

FQPA SFs

RfD, PAD, 

LOC for 

Risk 

Assessment

Study and Toxicological Effects

months), and LongTerm (>6 months) 

Dermal

mg/kg/day FQPA SF = 1X MOE = 100

Occupational 

LOC for 

MOE = 100

fetal body weight; increased incidences of fetal 

skeletal variations: hypoplastic or wavy ribs, 

incompletely ossified lumbar vertebral arches, 

and incompletely ossified ischia or pubes; and 

reduced number of thoracic vertebral and rib 

ossification sites.

Short- (1-30 days), 

Intermediate- (1-6 

months), and LongTerm (>6 months) 

Inhalation

NOAEL = 10 

mg/kg/day

100% 

inhalation 

absorption 

assumed

Residential:

UFA = 10X

UFH = 10X

FQPA SF = 10X

Residential 

LOC for 

MOE = 1000

Occupational 

LOC for 

MOE = 1000

Prenatal Developmental Toxicity - Rat

Developmental LOAEL = 25 mg/kg/day, based 

upon decreased mean fetal weights, and 

retardation in skeletal development evidenced by 

an increased number of litters with any variation 

and by decreased number of caudal vertebral and 

metacarpal ossification sites.

Occupational:

UFA = 10X

UFH = 10X

UFDB = 10X

Cancer (oral, dermal, 

inhalation)

Classification: Sulfentrazone is classified as “not likely to be carcinogenic to humans.”

NOAEL = no-observed adverse-effect level. LOAEL = lowest-observed adverse-effect level. UF = uncertainty factor. UFA = 

extrapolation from animal to human (interspecies). UFH = potential variation in sensitivity among members of the human 

population (intraspecies). UFL = extrapolation for use of a LOAEL in the absence of a NOAEL. FQPA SF = FQPA Safety 

Factor. PAD = population-adjusted dose (a = acute, c = chronic). RfD = reference dose. MOE = margin of exposure. LOC = 

level of concern.

5.0 Dietary Exposure and Risk Assessment 

Memo, G. Kramer, 14-JUN-2012; D389972

Memo, M. Barrett, 03-APR-2012; D39377 and D397770

Memo, J. Van Alstine, 14-JUN-2012; D389973

5.1 Metabolite/Degradate Residue Profile

5.1.1 Summary of Plant and Animal Metabolism Studies

The nature of the residue in plants is adequately understood. Data concerning the metabolism of 

sulfentrazone following preemergent applications in soybeans and confined rotational crops were 

submitted in conjunction with the soybean petition (PP#4F04407). The HED Metabolism 

Committee determined that the parent compound, sulfentrazone, and the metabolite HMS are the 

residues of concern in soybeans, and that sulfentrazone and the metabolites HMS and DMS are 

the residues of concern in rotational crops (G. Kramer, 14-JUN-1996; D226434). In addition, 

HED concluded that the results of the rotational crop metabolism studies may be translated to 

support preemergent uses on all types of crops (G. Kramer, 13-MAR-1996; D220548). Data 

concerning the metabolism of sulfentrazone following postemergent applications in corn, 

soybean, and radish were submitted in conjunction with the current petition. The metabolism of 

sulfentrazone following post-emergent application was similar to that seen in rotational crops 

and following preemergent application to soybean; no additional major metabolites were 

identified. HED concludes metabolism data are now available to support postemergence 

applications and that sulfentrazone and its metabolites HMS and DMS (free and conjugated) are 

the residues of concern in all crops except soybean seed, where the residues of concern are 

sulfentrazone and the metabolite HMS.
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The nature of the residue in livestock is adequately understood based on acceptable ruminant and 

poultry metabolism studies. The metabolism of sulfentrazone in livestock differs from that in 

plants as metabolism proceeds only by oxidation of the 3-methyl group to HMS, followed by 

further oxidation to form sulfentrazone carboxylic acid, which is decarboxylated to DMS. 

Sulfentrazone per se and its metabolites HMS and DMS were identified as the residues of 

concern in meat, milk, poultry, and eggs. 

5.1.2 Residues of Concern Summary and Rationale

The residues of concern in primary crops, rotational crops, livestock, and drinking water, as 

identified by the MARC, are shown in Table 5.1.2 below.

Table 5.1.2. Residues of Concern in Crops, Livestock, and Drinking Water.

Matrix Tolerance Expression Residues for Risk Assessment

Primary Crops, except 

soybean seed

sulfentrazone, HMS, DMS

(free and conjugated)

sulfentrazone, HMS, DMS 

(free and conjugated)

Soybean, seed sulfentrazone, HMS sulfentrazone, HMS

Rotational Crops sulfentrazone, HMS, DMS

(free and conjugated)

sulfentrazone, HMS, DMS

(free and conjugated)

Livestock sulfentrazone, HMS, DMS sulfentrazone, HMS, DMS

Water Not applicable. sulfentrazone, 3-carboxylic acid sulfentrazone

5.2 Food Residue Profile

The submitted field trial residue data for turnip (roots and tops), rhubarb, wheat (grown in the 

Pacific Northwest only), tree nut group 14, citrus fruit group 10-10, and the berry and small fruit 

group 13-07 are adequate. The field trial data reflect the proposed use patterns; an adequate 

number of trials were conducted in the appropriate geographic regions; and samples were 

analyzed for the residue of concern using validated data-collection methods. The storage 

intervals were also validated. Using the OECD tolerance calculation procedures for the residue 

data sets indicate that the requested tolerance levels are not appropriate for several commodities 

(Table 2.2.3). A revised Section F is requested. For clover and alfalfa, additional residue data 

and a ruminant feeding study are required.

The previously submitted residue data for sunflower seed are adequate to support the proposed 

crop subgroup tolerance for the combined residues of sulfentrazone, DMS, and HMS of 0.20 

ppm in/on sunflower, subgroup 20B. The established tolerances for the combined residues of 

sulfentrazone and its two metabolites of 0.15 ppm for pea, succulent, and bean, lima, succulent 

are being extrapolated to cowpea, succulent (regional tolerance in TN) and soybean, vegetable, 

succulent. Additionally, IR-4 has requested to amend the current tolerances in 40 CFR 180.498 

in or on bean, lima, succulent at 0.15 ppm by removing the tolerance from the table in Section 

(a)(2) and adding the tolerance to Section (c) Tolerances with regional registrations. Acceptable 

residue field trials in TN are available to support a regional registration. 
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No detectable residues were found in grapes and wheat grain treated at an exaggerated rate (5X); 

therefore, no grape or wheat processing studies were conducted. The submitted citrus processing 

study demonstrated that sulfentrazone residues of concern do not concentrate in citrus processed 

fractions as a result of the proposed use. Separate tolerances are not required for wheat, grape, 

and citrus processed commodities. 

Rotational crop studies for corn, rice, sorghum, and wheat were previously submitted in 

conjunction with the soybean petition (PP#4F04407). Permanent tolerances have been 

established for indirect or inadvertent residues of sulfentrazone and its metabolites, HMS and 

DMS, in cereal grains (excluding sweet corn), bran, forage, grain, hay, hulls, stover, and straw. 

As the 1X use rate in soybeans (0.375 lb ai/A) is greater than or equal to the 1X use rate of the 

proposed new uses, the established tolerances for indirect or inadvertent residues of 

sulfentrazone and its metabolites, HMS and DMS, are adequate to support the subject petition. 

The proposed rotational crop restrictions are adequate and consistent with previous sulfentrazone 

petitions.

Based on the available goat and poultry metabolism data and the previously calculated dietary 

exposures of livestock to sulfentrazone residues, HED had concluded that quantifiable residues 

of sulfentrazone were unlikely to occur in livestock commodities. As clover and alfalfa are 

significant feedstuffs for livestock (ruminants only), the dietary burden of sulfentrazone was 

recalculated for this petition using the Agency’s most recent guidance on constructing reasonably 

balanced livestock diets (Memo, G. Herndon, 30-JUN-2008). Based upon this diet and the 

results of the ruminant metabolism study, a ruminant feeding study is now required.

Summary tables of the residues from the crop field trials can be found in Appendix C.

5.3 Water Residue Profile

EFED provided estimated drinking water concentrations (EDWCs) for the combined residues of 

sulfentrazone and its major degradate, 3-carboxylic acid sulfentrazone, the residues of concern in 

drinking water (Memo, M. Barrett, 03-APR-2012; D39377 and D397770). The EDWCs were 

Tier 1 estimates for ground water using the Screening Concentration In Ground Water (SCIGROW) Model and surface water using the FQPA Index Reservoir Screening Tool (FIRST) 

Model. EFED believes that the Tier I models used for these crops provide a reasonable worstcase scenario, and provide estimates suitable for screening purposes. Application rates for the 

new uses (up to 0.375 lbs ai/A per season) are the same as or less than what was previously 

assessed; the addition of the proposed new uses does not result in changes to the exposure 

estimates used in the previous assessment. The EDWCs used in the current and previous 

assessments were based on the use of sulfentrazone on crops such as sugarcane, cabbage, 

potatoes, mint, or horseradish. 

For surface water, the acute (peak) sulfentrazone value is 32.0 ppb and the annual average value 

ranges from 0.5 ppb in alkaline or neutral waters (most common) to 5.1 ppb in acidic waters. 

The groundwater screening sulfentrazone concentration is 15.7 ppb. For 3-carboxylic acid 

sulfentrazone, the acute peak is 3.8 ppb and the annual average is 2.7 ppb. For 3-carboxylic acid 

sulfentrazone in groundwater, the concentration is 10.3 ppb. The drinking water estimates for 

use in human health risk assessment for sulfentrazone are shown in Table 5.3. 
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Table 5.3. Estimated Tier 1 Concentrations of Sulfentrazone and 3-Carboxylic Acid Sulfentrazone in 

Drinking Water Due to the Use of Sulfentrazone on Sugarcane, Cabbage, Potatoes, Mint, or 

Horseradish1,2.

Chemical Surface Water (ug/L) Groundwater (ug/L)

Acute Chronic Acute and Chronic

Sulfentrazone 32.0 5.1 15.7

3-Carboxylic Acid Sulfentrazone 3.8 2.7 10.3

Total 35.8 7.8 26.0

1 These crops were chosen for this assessment because the label permits use of the maximum application rate (0.375 pounds 

active ingredient per acre) and aerial application.

2 The bolded total values are the estimates used in the dietary risk assessment.

5.4 Dietary Risk Assessment

5.4.1 Description of Residue Data Used in Dietary Assessment

Conservative unrefined acute and chronic dietary (food and drinking water) exposure 

assessments were performed for the general U.S. population and all population subgroups. 

Assumptions for these assessments included tolerance-level residues for all commodities, 100% 

CT, and DEEMTM 7.81 default processing factors. Drinking water estimates were provided by 

EFED for the combined residues of sulfentrazone and its major degradate, 3-carboxylic acid 

sulfentrazone based on the use of sulfentrazone on crops such as sugarcane, cabbage, potatoes, 

mint, or horseradish. The acute assessment incorporated a surface water EDWC of 0.0358 ppm, 

calculated using the FIRST Model, and the chronic assessment incorporated a groundwater 

EDWC of 0.026 ppm, calculated using the SCI-GROW Model. 

5.4.2 Percent Crop Treated Used in Dietary Assessment

The acute and chronic dietary analyses assumed 100% CT for all commodities. 

5.4.3 Acute Dietary Risk Assessment

Acute dietary risk estimates (food and drinking water) are not of concern for the general 

population or any other population subgroup. The highest exposure estimate was for the 

population subgroup children 1-2 years old, which utilized <1% of the aPAD for sulfentrazone. 

Females 13-49 years old have a lower aPAD than the general population. As a result, even 

though the exposure estimate for females 13-49 years old was lower than the estimate for 

children 1 to 2 years old, females 13-49 years old have the highest risk estimate (3% aPAD). 

The acute exposure estimate for the general U.S. population utilized <1% of the aPAD. A 

summary table of dietary exposure and risk for sulfentrazone can be found in Section 5.4.6. 

5.4.4 Chronic Dietary Risk Assessment

Chronic dietary risk estimates (food and drinking water) are not of concern for the general 

population or any other population subgroup. The highest exposure and risk estimates were for 

the population subgroup children 1-2 years old, which utilized 4% of the cPAD for 

sulfentrazone. The chronic exposure estimate for the general U.S. population utilized 2% of the 

cPAD. A summary table of dietary exposure and risk for sulfentrazone can be found in Section 

5.4.6. 
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5.4.5 Cancer Dietary Risk Assessment

A cancer dietary assessment was not conducted because sulfentrazone is classified as “not likely 

to be carcinogenic to humans.”

5.4.6 Summary Table

Table 5.4.6. Summary of Acute and Chronic Dietary (Food and Drinking Water) Exposure and Risk 

for Sulfentrazone.1

Population Subgroup

95th Percentile cPAD 

(mg/kg/day)

Exposure 

(mg/kg/day) aPAD %cPAD

(mg/kg/day)

Exposure 

(mg/kg/day) %aPAD

General U.S. Population

2.5

0.006238 <1.0

0.14

0.002422 1.7

All Infants (< 1 year old) 0.010530 <1.0 0.003720 2.7

Children 1-2 years old 0.013972 <1.0 0.005855 4.2

Children 3-5 years old 0.011379 <1.0 0.005258 3.8

Children 6-12 years old 0.007727 <1.0 0.003456 2.5

Youth 13-19 years old 0.005499 <1.0 0.002287 1.6

Adults 20-49 years old 0.004429 <1.0 0.001966 1.4

Adults 50+ years old 0.003962 <1.0 0.001838 1.3

Females 13-49 years old 0.14 0.004466 3.2 0.001955 1.4

1 The populations with the greatest risk estimates are bolded.

6.0 Residential (Non-Occupational) Exposure/Risk Characterization

Memo, K. Lowe, 17-MAY-2012, D389974

6.1 Residential Handler Exposure

The proposed uses will not result in residential exposure; however, the currently registered turf 

use has been reassessed to reflect updates to HED’s 2012 Residential SOPs. The residential 

exposures were revised since they impact the aggregate assessment for sulfentrazone. 

According to the Human-Health Assessment Scoping Document in Support of Registration 

Review (Memo, K. Lowe et al., D369064, 9/9/09), the formulations registered for use on turf 

include liquids, DFs, and granules at a maximum rate of 0.375 lb ai/A. The residential handler 

exposure assessment estimates dermal and inhalation exposures for individuals using 

sulfentrazone on residential turfgrass. There are sulfentrazone labels that indicate application by 

professional lawncare operators only; however, a residential handler assessment has been 

included to cover the possibility of homeowner applications since the products are not restricteduse. 

Unit exposure values and estimates for area treated were taken from HED’s 2012 Residential 

SOPs: Lawns/Turf. The baseline dermal exposures assumed that residential handlers wore 

shorts, a short-sleeved shirt, and no gloves, and the baseline inhalation exposures did not assume 

the use of a respirator. 

Short-term risk estimates for residential handlers are presented in Table 6.1. Intermediate-term 

exposures are not likely because of the intermittent nature of applications by homeowners. 

Dermal MOEs range from 1,100 (mixing/loading/applying DFs with manually-pressurized 
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handwand and backpack sprayers) to 73,000,000 (loading/applying granules by cup and shaker 

can). Inhalation MOEs range from 6,600 (mixing/loading/applying DFs with manuallypressurized handwand and backpack sprayers) to 62,000,000 (loading/applying granules by cup 

and shaker can). The combined dermal and inhalation exposure risk estimates for residential 

handlers are not of concern (i.e., ARIs>1) at baseline for all scenarios. The risk estimates shown 

in Table 6.1 indicate that if a residential handler were to obtain the product and apply it in 

accordance with the proposed label, then the dermal and inhalation exposure and risk estimates 

would not be of concern. 
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Table 6.1. Residential Handler Exposure and Risk Estimates for Sulfentrazone Applications to Turfgrass.

Exposure Scenario Application 

Rate1

Area 

Treated 

Daily2

Baseline Unit 

Exposures (mg/lb ai)

Baseline Dose4

(mg/kg/day) Baseline MOE5 Dermal 

Risk 

Index6

Inhalation 

Risk 

Index7

ARI8

Dermal3Inhalation3 Dermal Inhalation Dermal Inhalation

Loader/Applicator for Granules

Push-type spreaders 0.375 lb ai/A 0.5 A 0.81 0.0026 0.0022 0.0000071 45,000 1,400,000 450 1,400 340

Belly grinders 0.375 lb ai/A 0.023 A 360 0.039 0.045 0.0000049 2,200 2,100,000 22 2,100 22

Spoon 0.375 lb ai/A 0.002 A 6.2 0.087 0.000077 0.0000011 1,300,000 9,200,000 13,000 9,200 5,400

Cup 0.375 lb ai/A 0.002 A 0.11 0.013 0.0000014 1.6E-07 73,000,000 62,000,000 730,000 62,000 57,000

Hand dispersal 0.375 lb ai/A 0.002 A 160 0.38 0.0020 0.0000047 50,000 2,100,000 500 2,100 400

Shaker can 0.375 lb ai/A 0.002 A 0.11 0.013 0.0000014 1.6E-07 73,000,000 62,000,000 730,000 62,000 57,000

Mixer/Loader/Applicator for Liquids

Manually-pressurized handwand 0.019 lb ai/gal 5 gal 63 0.018 0.087 0.000025 1,200 400,000 12 400 12

Hose-end sprayer 0.375 lb ai/A 0.5 A 13.4 0.022 0.036 0.000060 2,700 170,000 27 170 23

Backpack 0.019 lb ai/gal 5 gal 130 0.14 0.18 0.00019 560 52,000 5.6 52 5.1

Sprinkler can 0.375 lb ai/A 0.023 A 13.4 0.022 0.0017 0.0000027 60,000 3,600,000 600 3,600 510

Mixer/Loader/Applicator for Dry Flowables

Manually-pressurized handwand 0.019 lb ai/gal 5 gal 69 1.1 0.095 0.0015 1,100 6,600 11 6.6 4.1

Hose-end sprayer 0.375 lb ai/A 0.5 A 13.4 0.022 0.036 0.000060 2,700 170,000 27 170 23

Backpack 0.019 lb ai/gal 5 gal 69 1.1 0.095 0.0015 1,100 6,600 11 6.6 4.1

Sprinkler can 0.375 lb ai/A 0.023 A 13.4 0.022 0.0017 0.0000027 60,000 3,600,000 600 3,600 510

1. Application rates based on communication between the Registrant and EPA regarding the maximum rates allowed on the labels for the residential use sites. From label 279-3323: 0.375 lb ai/A * 20 

gal/A = 0.019 lb ai/gal.

2. Based on HED’s SOPs: Lawns/Turf (January 2012). 0.023 A = 1000 ft2. 0.002 A = 100 ft2.

3. Baseline Dermal: Short-sleeve shirt, shorts, and no gloves; Baseline Inhalation: no respirator. 

4. Dose (mg/kg/day) = daily unit exposure (mg/lb ai) x application rate (lb ai/gal) x gal treated * body weight (69 kg).

5. MOE = NOAEL (Dermal = 100 mg/kg/day; Inhalation = 10 mg/kg/day) / daily dose (mg/kg/day). Level of concern = 100.

6. Dermal Risk Index = Dermal MOE / Dermal LOC. Dermal LOC = 100.

7. Inhalation Risk Index = Inhalation MOE / Inhalation LOC. Inhalation LOC = 1000.

8. ARI = 1 / ((1 ÷ Dermal Risk Index) + (1 ÷ (Inhalation Risk Index)).
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6.2 Post-Application Exposure

Sulfentrazone can be used in many areas that can be frequented by the general population 

including residential areas (e.g., home lawns). As a result, individuals can be exposed by 

entering these areas if they have been previously treated. Potential exposure scenarios, routes of 

exposure, and lifestages assessed include:

Physical activities on turf: adults (dermal) and children 1 < 2 years old (dermal and 

incidental oral);

Mowing: adults (dermal) and children 11 < 16 years old (dermal); and

Golfing: adults (dermal), children 11 < 16 years old (dermal), and children 6 < 11 years 

old (dermal).

The lifestages (i.e., adults, children 1<2 years old, children 11 < 16 years old, and children 6 < 

11 years old) selected for each post-application scenario are based on an analysis provided as an 

Appendix in the 2012 Residential SOPs. These lifestages are not the only lifestages that could 

be potentially exposed for these post-application scenarios; however, the assessment of these 

lifestages is health protective for the exposures and risks for any other potentially exposed 

lifestages.

Short-term dermal and incidental oral exposures to sulfentrazone were assessed and are 

presented in Table 6.2. There is the potential for intermediate-term exposure to sulfentrazone in 

the soil due to its half-life of 545 days; however, since the maximum yearly application rate is 

the same as the maximum single application rate, the short-term assessment is protective of 

intermediate-term soil ingestion exposure. The residential post-application scenarios were 

assessed using standard default assumptions and inputs from HED’s 2012 Residential SOPs. All 

adult and children post-application dermal scenarios resulted in MOEs greater than the LOC 

(MOE = 100) for short-term exposure. The lowest dermal MOE (370) represents children 1 < 2 

years old doing physical activities on turf that had been treated with a liquid formulation of 

sulfentrazone. Incidental oral scenarios for children 1 < 2 years old resulted in MOEs greater 

than the LOC (MOE = 100), with the lowest MOE being 1,100 for episodic granular ingestion. 

Non-dietary ingestion of granules is considered to be an episodic event and, as such, is compared 

to the acute dietary POD, and is not combined with other sources of exposure. 
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Table 6.2. Short-Term Residential Post-application Exposure and Risk Estimates for Sulfentrazone.

Lifestage Post-application Exposure Scenario Dose (mg/kg/day)a MOEs

Liquid Formulation

Adult Turf

Liquid 

formulation

0.375 lb 

ai/A

Dermal Physical Activities on Turf 0.16 610

Mowing 0.0033 30,000

Golfing 0.013 7,800

Child 11 < 16 

years old

Dermal Mowing 0.0033 30,000

Golfing 0.013 7,700

Child 6 < 11 

years old

Dermal Golfing 0.015 6,600

Child 1 < 2 

year old

Dermal Physical Activities on Turf 0.27 370

Hand-to-Mouth 0.0056 2,500

Object-to-Mouth 0.00017 82,000

Short- and Intermediate-term Incidental Soil 

Ingestion

1.2 x 10-51,100,000

Granular Formulation

Adult Turf

Granular 

formulation

0.375 lb 

ai/A

Dermal Physical Activities 

on Turf

0.036 2,800

Mowing 0.00066 150,000

Golfing 0.0026 39,000

Child 11 < 16 

years old

Dermal Mowing 0.00066 150,000

Golfing 0.0026 39,000

Child 6 < 11 

years old

Dermal Golfing 0.0030 33,000

Child 1 < 2 

year old

Dermal Physical Activities 

on Turf

0.059 1,700

Hand-to-Mouth 0.00055 25,000

Object-to-Mouth 0.00017 82,000

Short- and Intermediate-term Incidental Soil 

Ingestion

1.2 x 10-51,100,000

0.9% ai Episodic Granular Ingestion 0.24 1,100

a. Dose equations:

(1) Dermal dose = turf transferable residue (ug/cm2) * (0.001 mg/ug) * transfer coefficient (cm2/hr) * exposure time (hr/day) / body weight 

(kg).

(2) Hand-to-mouth dose = hand residue loading (mg/cm2) * fraction hand mouthed/event * surface area of hand (cm2) * exposure time 

(hr/day) * replenishment intervals/hr * saliva extraction factor * number of contacts per hour (events/hr) / body weight (kg).

(3) Object-to-mouth dose = object residue loading (mg/cm2) * surface area of object mouthed (cm2) * exposure time (hr/day) * 

replenishment intervals/hr * saliva extraction factor * number of contacts per hour (events/hr) / body weight (kg).

(4) Soil ingestion dose = soil residue (ug/g) * ingestion rate of soil (mg/day) * 0.000001 g/ug / body weight (kg).

(5) Granular ingestion dose = ingestion rate of dry pesticide formulation (g/day) * fraction of ai in dry formulation * 1000 mg/g).

b. MOE = POD (mg/kg/day) / Dermal or incidental oral dose (mg/kg/day), where dermal POD = 100 mg/kg/dat; incidental oral POD = 14 

mg/kg/day; acute dietary POD = 250 mg/kg/day.

6.3 Combined Exposure

HED combines risk estimates resulting from separate exposure scenarios when it is likely they 

can occur simultaneously based on the use pattern and the behavior associated with the exposed 

population, and when similar toxicological effects occur from different routes of exposure. HED 

reviewed all residential sources of exposure to determine which residential exposure scenarios 

would be appropriate to combine.

HED assessed both adult handler and post-application exposure resulting from treatment of 

residential lawns; however, HED did not combine exposure resulting from adult handler and 

post-application exposure because of the conservative assumptions and inputs within each 
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estimated exposure scenario. The likelihood that a homeowner would treat their lawn and then 

repeatedly re-enter the treated site continuously for 30 days is minimal. Furthermore, it is 

unlikely that a homeowner would treat their lawn and then play golf on a course treated with the 

same pesticide on the same day. HED believes that combining co-occurring exposures resulting 

from handler and post-application exposure would result in an overestimate of adult exposure. 

Therefore, HED selected the most conservative combined adult residential scenario, handler 

exposure (backpack scenario for liquids with an ARI of 5.1) as the contributing source of adult 

residential exposure. 

There is the potential for post-application dermal and incidental oral exposure for children 1 < 2 

years resulting from use of sulfentrazone on turf. Since the toxicological effects from the dermal 

and oral routes of exposure are the same, a total residential exposure assessment was conducted 

for children. The incidental oral scenarios (i.e., hand-to-mouth, object-to-mouth, and soil 

ingestion) should be considered inter-related and it is likely that they occur interspersed amongst 

each other across time. Combining all three of these scenarios with the dermal exposure scenario

would be overly-conservative because of the conservative nature of each individual assessment. 

Therefore, for the short-term exposure duration, the post-application exposure scenarios that 

were combined for children 1 to < 2 years old are the dermal and hand-to-mouth scenarios. This 

combination should be considered a protective estimate of children’s exposure to pesticides used 

on turf. For the intermediate-term exposure duration, the only potential post-application 

exposure scenario is soil ingestion. The total residential children’s short-term post-application 

exposure assessment results in an MOE greater than HED’s LOC (MOE = 320) and is not a risk 

of concern. The total residential children’s intermediate-term post-application exposure 

assessment also results in an MOE greater than HED’s LOC (MOE = 1,100,000).
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Table 6.3. Short- and Intermediate-Term Residential Exposures for the Sulfentrazone Combined Residential Risk Calculations.1

Population

Handler Exposure 

(mg/kg/day)2 Dermal Inhalation

Aggregate 

Risk Index5

Post-application Exposure 

(mg/kg/day)6

Residential 

Postapplication 

Total 

Exposure 

(mg/kg/day)7

Residential 

Postapplication 

Total MOE Dermal Inhalation MOE Risk Index 8

3 MOE Risk Index4 Dermal Inhalation Oral

Short-Term

Adult Male 0.095 0.0015 1,100 11 6,600 6.6 4.1 0.16 N/A N/A 0.16 610

Child 1 to < 2 

years old N/A 0.27 N/A 0.0056 0.2756 320

Intermediate-Term

Child 1 to < 2 

years old N/A N/A N/A 1.2 x 10-5

1.2 x 10-51,100,000

1. Bolded risk estimates should contribute to the residential exposure portion of the aggregate assessment. 

2. Handler exposure represents high-end handler exposure, where the exposure duration is appropriate to assess.

3. Dermal Risk Index = Dermal MOE / Dermal LOC. Dermal LOC = 100.

4. Inhalation Risk Index = Inhalation MOE / Inhalation LOC. Inhalation LOC = 1000.

5. ARI = 1 / ((1 ÷ Dermal Risk Index) + (1 ÷ (Inhalation Risk Index).

6. Post-application exposure represents high-end dermal, inhalation and/or incidental oral exposure for the relevant exposure duration.

7. For adults, residential total exposure combines the highest dermal and inhalation exposures (Table 6.1), where applicable. For young children, total residential exposure 

combines high-end post application incidental oral AND dermal exposure, where applicable (Table 6.2).

8. Total MOE = 1/ (1/Dermal MOE) + (1/Inhalation MOE) + (1/Incidental oral MOE). Dermal NOAEL = 100 mg/kg/day, Inhalation NOAEL = 10 mg/kg/day; Incidental oral 

NOAEL = 14 mg/kg/day.
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6.4 Residential Bystander Post-application Inhalation Exposure

Based on the Agency's current practices, a quantitative post-application inhalation exposure 

assessment was not performed for sulfentrazone at this time. However, volatilization of 

pesticides may be a source of post-application inhalation exposure to individuals nearby 

pesticide applications. The Agency sought expert advice and input on issues related to 

volatilization of pesticides from its Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) 

Scientific Advisory Panel (SAP) in December 2009, and received the SAP’s final report on 

March 2, 2010 (http://www.epa.gov/scipoly/SAP/meetings/2009/120109meeting.html). The 

Agency is in the process of evaluating the SAP report and may, as appropriate, develop policies 

and procedures to identify the need for and, subsequently, the way to incorporate postapplication inhalation exposure into the Agency's risk assessments. If new policies or 

procedures are developed, the Agency may revisit the need for a quantitative post-application 

inhalation exposure assessment for sulfentrazone.

6.5 Spray Drift

Spray drift is always a potential source of exposure to residents nearby to spraying operations. 

This is particularly the case with aerial application, but, to a lesser extent, could also be a 

potential source of exposure from the ground application method employed for sulfentrazone. 

The Agency has been working with the Spray Drift Task Force, EPA Regional Offices, and State 

Lead Agencies for pesticide regulation and other parties to develop the best spray-driftmanagement practices (see the Agency’s Spray Drift website for more information at 

http://www.epa.gov/opp00001/factsheets/spraydrift.htm). On a chemical-by-chemical basis, the 

Agency is now requiring interim mitigation measures for aerial applications that must be placed 

on product labels/labeling. The Agency has completed its evaluation of the new database 

submitted by the Spray Drift Task Force, a membership of U.S. pesticide registrants, and is 

developing a policy on how to appropriately apply the data and the AgDRIFT®computer model 

to its risk assessments for pesticides applied by air, orchard airblast, and ground hydraulic 

methods. After the policy is in place, the Agency may impose further refinements in spray-driftmanagement practices to reduce off-target drift with specific products with significant risks 

associated with drift.

Although a quantitative residential post-application inhalation exposure assessment was not 

performed as a result of pesticide drift from neighboring treated agricultural fields, an inhalation 

exposure assessment was performed for flaggers. This exposure scenario is representative of a 

worse case inhalation (drift) exposure and may be considered protective of most outdoor 

agricultural and commercial post-application inhalation exposure scenarios. 

7.0 Aggregate Exposure/Risk Characterization

In accordance with the FQPA, HED must consider and aggregate (add) pesticide exposures and 

risks from three major sources: food, drinking water, and residential exposures. In an aggregate 

assessment, exposures from relevant sources are added together and compared to quantitative 

estimates of hazard (e.g., a NOAEL or PAD), or the risks themselves can be aggregated. When 

aggregating exposures and risks from various sources, HED considers both the route and 

duration of exposure. 
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7.1 Acute Aggregate Risk

Acute aggregate risk results from exposure to residues in food and drinking water alone. The 

acute dietary exposure analysis included both food and drinking water. Therefore, acute 

aggregate risk is equivalent to the acute dietary risk, as discussed in Section 5.4.3, above. All 

risk estimates are below the LOC. 

7.2 Short- and Intermediate-Term Aggregate Risk

Short- and intermediate-term aggregate exposure takes into account short- and intermediate-term 

residential exposure plus chronic exposure to food and water (considered to be a background 

exposure level). Sulfentrazone is currently registered for uses that could result in short- and 

intermediate-term residential exposure, and RAB1 has determined that it is appropriate to 

aggregate chronic exposure through food and water with short- and intermediate- term residential 

exposures to sulfentrazone. For short- and intermediate-term exposures, incidental oral, dermal, 

and inhalation exposure risk assessments are appropriate to aggregate due to similarities in the 

toxicity endpoints observed between the oral and dermal routes. The short- and intermediateterm incidental oral, dermal, and inhalation exposures are combined with chronic dietary (food 

and water) exposure for determination of aggregate short- and intermediate-term exposures. 

HED uses chronic dietary exposure when conducting short- and intermediate-term aggregate 

assessments as they have determined that these will more accurately reflect exposure from food 

over the HED defined short- and intermediate-term interval than will acute exposure. 

Adults may potentially be exposed to sulfentrazone through dermal, inhalation, and dietary (food 

and drinking water) routes. It was appropriate to aggregate handler dermal and inhalation 

exposures with dietary (food and water) exposures. The backpack scenario for mixing and 

loading dry flowables is the exposure scenario with the greatest risk estimate; therefore, the 

exposure estimates for this scenario are protective of other exposure scenarios. The LOC for oral 

exposures (MOEs <100) and inhalation exposures (MOEs <1000) are different, a total ARI 

approach was used for adults. ARIs of <1 are risk estimates of concern. For young children, due 

primarily to their hand-to-mouth activities, short-term oral (non-dietary) exposures are expected 

along with dermal and dietary (food and drinking water) exposures; therefore, it was appropriate 

to aggregate these exposures for the short-term duration. For the intermediate-term exposure 

duration, the only potential post-application exposure scenario is soil ingestion; therefore, this 

exposure was aggregated with dietary (food and drinking water) for the intermediate-term 

duration. Children 1-2 years old represent the population subgroup for children with the greatest 

exposure; therefore, the exposure estimates for children 1-2 years old are protective of other 

children population subgroups. The LOC is 100; therefore MOEs <100 are risk estimates of 

concern. 

Tables 7.2.1, 7.2.2, and 7.2.3 summarize the short- and intermediate-term aggregate exposures 

and risk estimates for 1 -2 year olds and adults. The aggregate short- and intermediate-term 

ARIs are >1 for adults and the aggregate MOEs are >100 for children; therefore, aggregate 

exposures to sulfentrazone are not of concern to HED.
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Table 7.2.1. Short-term Aggregate Risk Calculations for Children 1-2 Years Old.

Population LOC

Background Dietary + Incidental Oral Exposures Residential Exposures Aggregate 

MOE (food, 

water, and 

residential)4

Chronic Food 

and Water 

Exposure 

(mg/kg/day)

Incidental 

Oral 

Exposure 

(mg/kg/day)1

Oral MOE2

Dermal 

Exposure 

(mg/kg/day)

Dermal 

MOE3

Children 1-

2 years old 100 0.005855 0.0056 1220 0.27 370 280

1. Short-term Incidental Oral Exposure = Hand-to-Mouth exposure. 

2. Oral MOE = NOAEL (14 mg/kg/day) ÷ (chronic food/water exposure + incidental oral exposure).

3. Dermal MOE = NOAEL (100 mg/kg/day) ÷ (dermal exposure). 

4. Aggregate MOE = 1/[(1/oral MOE) + (1/dermal) + (1/inhalation)].

Table 7.2.2. Intermediate-term Aggregate Risk Calculations for Children 1-2 Years Old.

Population LOC

Background Dietary + Incidental Oral Exposures Aggregate MOE 

(food, water, and 

residential)2

Chronic Food and 

Water Exposure 

(mg/kg/day)

Incidental Oral Exposure 

(mg/kg/day)1

Children 1-2 years 

old 100 0.005855 0.000012 2390

1

Short-term Incidental Oral Exposure = soil ingestion. 

2 Aggregate MOE = NOAEL (14 mg/kg/day) ÷ (chronic food/water exposure + incidental oral exposure).

Table 7.2.3. Short-Term Aggregate Risk Calculations for Adults.1

Population

Dietary Exposure2 Dermal Residential Exposure3Inhalation Residential Exposure4

Aggregate 

ARI (food, 

water, and 

residential)5

Chronic Food 

and Water 

Exposure 

(mg/kg/day)

MOE ARI

Dermal 

Exposure 

(mg/kg/day)

MOE ARI

Inhalation 

Exposure 

(mg/kg/day)

MOE ARI

General U.S. 

Population 0.002422 5780 58 0.095 1,100 11 0.0015 6600 6.6 3.9

Adult Male 0.001966 7120 71 0.095 1,100 11 0.0015 6600 6.6 3.9

1. HED is not concerned when ARIs are >1. 

2. MOE dietary = [(short- or intermediate-term oral NOAEL = 14 mg/kg/day)/(chronic dietary exposure)]. ARI dietary = [(MOE 

dietary)/(LOC (100))]. 

3. MOE dermal = [(short- or intermediate-term dermal NOAEL = 100 mg/kg/day)/(high-end dermal residential exposure)]. ARI 

dermal = [(MOE dermal)/(LOC (100))]. Exposure values from Table 6.3. 

4. MOE inhalation = [(short- or intermediate-term inhalation NOAEL = 10 mg/kg/day)/(high-end inhalation residential 

exposure)]. ARI inhalation = [(MOE inhalation)/(LOC (1000))]. Exposure values from Table 6.3. 

5. ARI Aggregate = 1/[(1/ARI dietary) + (1/ARI oral) + (1/ARI dermal) + (1/ARI inhalation)].

7.3 Chronic Aggregate Risk

The chronic aggregate risk assessment results from long-term exposure to residues in food and 

drinking water, as there are no residential scenarios that result in long-term exposure. The 

chronic dietary exposure analysis included both food and drinking water and, therefore, the 

chronic aggregate risk assessment is equivalent to the chronic dietary risk assessment discussed 

in Section 5.4.4, above. All risk estimates are below HED’s LOC. 

7.4 Cancer Aggregate Risk

An aggregate cancer risk assessment was not performed because sulfentrazone is not considered 

to be a carcinogen. 
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8.0 Cumulative Exposure/Risk Characterization

Unlike other pesticides for which EPA has followed a cumulative risk approach based on a 

common mechanism of toxicity, EPA has not made a common mechanism of toxicity finding as 

to sulfentrazone and any other substances and sulfentrazone does not appear to produce a toxic 

metabolite produced by other substances. For the purposes of this tolerance action, therefore, 

EPA has not assumed that sulfentrazone has a common mechanism of toxicity with other 

substances. For information regarding EPA’s efforts to determine which chemicals have a 

common mechanism of toxicity and to evaluate the cumulative effects of such chemicals, see the 

policy statements released by EPA’s Office of Pesticide Programs concerning common 

mechanism determinations and procedures for cumulating effects from substances found to have 

a common mechanism on EPA’s website at http://www.epa.gov/pesticides/cumulative/.

9.0 Occupational Exposure/Risk Characterization

9.1 Short-/Intermediate-Term Handler Risk

Based on the anticipated use patterns, current labeling, and types of equipment that can 

potentially be used, occupational handler exposure is expected from the proposed uses. 

No chemical-specific data were available to assess potential exposure to pesticide handlers. 

Sources of generic data, used as surrogate data in the absence of chemical-specific data, include 

the Pesticide Handlers Exposure Database Version 1.1 (PHED 1.1), the Agricultural Handler 

Exposure Task Force (AHETF), and the Agricultural Reentry Task Force (ARTF). Some of 

these data are proprietary, and subject to the data protection provisions of FIFRA. 

Based on the activity use pattern, the duration of exposure is expected to be short-term (1 to 30 

days). Intermediate-term exposures are less likely; however, the short- and intermediate-term 

PODs are the same; therefore, short-term estimated risk estimates are protective of intermediateterm exposures. Long-term exposures (>6 months) are not anticipated based on the proposed use 

pattern, so a long-term assessment was not conducted. The sulfentrazone product labels direct 

mixers, loaders, applicators, and other handlers to wear a long-sleeved shirt and long pants, 

chemical-resistant gloves, and shoes plus socks.

Table 9.1.1 presents the exposure/risk estimates for short- and intermediate-term dermal and 

inhalation exposures for liquid and DF formulation applications. The combined dermal and 

inhalation exposure risk estimates are not of concern (i.e., ARIs >1) at baseline (i.e., single layer 

of clothing, no gloves, no respirator) for all scenarios, except the following, which require 

additional PPE beyond what is currently on the labels:

Mixing/loading DFs for chemigation and groundboom applications requires the addition 

of gloves and a PF5 respirator;

Mixing/loading/applying liquids for soil-directed applications with mechanicallypressurized handgun requires the addition of gloves and a PF5 respirator; and

Mixing/loading DFs for aerial application requires the addition of gloves and a PF10 

respirator.

Table 9.1.2 presents the exposure/risk estimates for short- and intermediate-term dermal and 
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inhalation exposures for dry bulk fertilizer applications. The combined dermal and inhalation 

exposure risk estimates are not of concern (i.e., ARIs >1) for all scenarios, except the following:

Mixing/loading DFs for commercial impregnation of dry bulk fertilizers results in risk 

estimates of concern using surrogate closed mixing/loading exposure data and assuming 

960 tons treated daily.

The estimate for amount of dry bulk fertilizer treated is based on use data submitted previously 

for another chemical and is the best data currently available to HED. Chemical-specific use data 

could be submitted to refine the assessment. 
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Table 9.1.1. Short-/Intermediate-Term Occupational Exposure and Risk Estimates for Sulfentrazone.

Exposure 

Scenario

Dermal Unit 

Exposure

(ug/lb ai)1

Inhalation 

Unit 

Exposure

(ug/lb ai)1

Application 

Rate2

Amount 

Treated 

Daily3

Dose (mg/kg/day)4,5 MOE6,7

Dermal 

Risk 

Index8

Inhalation 

Risk 

Index9

ARI10

Dermal Inhalation

Dermal

(LOC = 

100)

Inhalation

(LOC = 

1000)

Mixer/Loader DFs

Aerial 

Application

Baseline: 

227

SL w/G: 

51.6

Baseline: 

8.96

PF5 R: 1.79

PF10 R: 0.9

0.375 lb 

ai/A 1200 A

Baseline: 

1.5

SL w/G: 

0.34

Baseline: 

0.058

PF5: 0.012

PF10: 0.0059

Baseline: 

68

SL w/G: 

300

Baseline: 

170

PF5: 860

PF10: 1,700

Baseline: 

0.68

SL w/G: 

3

Baseline: 

0.17

PF5: 0.86

PF10: 1.7

Baseline: 0.14

SL w/G + No 

R: 0.16

SL w/G + 

PF5: 0.67

SL w/G + 

PF10: 1.1

Chemigation 

Applications

Baseline: 

227

SL w/G: 

51.6

Baseline: 

8.96

PF5 R: 1.79

0.375 lb 

ai/A 350 A

Baseline: 

0.43

SL w/G: 

0.098

Baseline: 

0.017

PF5: 0.0034

Baseline: 

230

SL w/G: 

1,000

Baseline: 

590

PF5: 2,900

Baseline: 

2.3

SL w/G: 

10 

Baseline: 

0.59

PF5: 2.9

Baseline: 0.47

SL w/G + No 

R: 0.56

SL w/G + 

PF5: 2.2

Groundboom 

Applications

Baseline: 

227

SL w/G: 

51.6

Baseline: 

8.96

PF5 R: 1.79

0.375 lb 

ai/A 200 A

Baseline: 

0.25

SL w/G: 

0.056

Baseline: 

0.0097

PF5: 0.0019

Baseline: 

410

SL w/G: 

1,800

Baseline: 

1,000

PF5: 5,100

Baseline: 

4.1 

SL w/G: 

18

Baseline: 1

PF5: 5.1

Baseline: 0.8

SL w/G + No 

R: 0.95

SL w/G + 

PF5: 4

Mixer/Loader Liquids

Aerial 

Application

Baseline: 

220

SL w/G: 

37.6

Baseline: 

0.219

0.375 lb 

ai/A 1200 A

Baseline: 

1.4

SL w/G: 

0.25

Baseline: 

0.0014

Baseline: 

70

SL w/G: 

410

Baseline: 

7,000

Baseline: 

0.7

SL w/G: 

4.1

Baseline: 7

Baseline: 

0.64

SL w/G + No 

R: 2.6

Chemigation 

Applications

Baseline: 

220

Baseline: 

0.219

0.375 lb 

ai/A 350 A Baseline: 0.42

Baseline: 

0.00042

Baseline: 

240

Baseline: 

24,000

Baseline: 

2.4

Baseline: 

24 Baseline: 2.2

Groundboom 

Applications

Baseline: 

220

Baseline: 

0.219

0.375 lb 

ai/A 200 A Baseline: 0.24

Baseline: 

0.00024

Baseline: 

420

Baseline: 

42,000

Baseline: 

4.2

Baseline: 

42 Baseline: 3.8
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Table 9.1.1. Short-/Intermediate-Term Occupational Exposure and Risk Estimates for Sulfentrazone.

Exposure 

Scenario

Dermal Unit 

Exposure

(ug/lb ai)1

Inhalation 

Unit 

Exposure

(ug/lb ai)1

Application 

Rate2

Amount 

Treated 

Daily3

Dose (mg/kg/day)4,5 MOE6,7

Dermal 

Risk 

Index8

Inhalation 

Risk 

Index9

ARI10

Dermal Inhalation

Dermal

(LOC = 

100)

Inhalation

(LOC = 

1000)

Applicator

Applicator, 

Aerial, FixedWingEC: 5 EC: 0.068 0.375 lb 

ai/A 1200 A EC: 0.033 EC: 0.00044 EC: 3,100 EC: 23,000 EC: 31 EC: 23 EC: 13

Applicator, 

Open Cab 

Groundboom

Baseline: 

78.6

Baseline: 

0.34

0.375 lb 

ai/A 200 A Baseline: 0.085

Baseline: 

0.00037

Baseline: 

1,200

Baseline: 

27,000

Baseline: 

12

Baseline: 

27 Baseline: 8.3

Flagger

Flagger Baseline: 11 Baseline:

0.35

0.375 lb 

ai/A 350 A Baseline: 0.021

Baseline: 

0.00067

Baseline: 

4,800

Baseline: 

15,000

Baseline: 

48

Baseline: 

15 Baseline: 11

Mixer/Loader/Applicator

Mechanicallypressurized 

Handgun 

Sprayer – Soil 

Directed 

Application

Baseline: 

4,310

SL w/G: 

4,310

Baseline: 

3,931

PF5: 786

0.375 lb 

ai/A 1 A

Baseline: 

0.023

SL w/G: 

0.023

Baseline: 

0.021

PF5: 0.0043

Baseline: 

4,300

SL w/G: 

4,300

Baseline: 

470

PF5: 2,300

Baseline: 

43

SL w/G: 

43

Baseline: 

0.47

PF5: 2.3

Baseline: 

0.46

SL w/G + No 

R: 0.46

SL w/G + 

PF5: 2.2

1. Based on “Occupational Pesticide Handler Unit Exposure Surrogate Reference Table” (September 26, 2011); includes data from PHED/ORETF/AHETF (level of mitigation: Baseline and PPE 

(gloves)). Baseline = single layer and no gloves; no respirator; SL w/G = single layer w/glove; PF5 R = PF5 Respirator; PF10 R = PF 10 Respirator; EC = Engineering control.

2. Based on proposed labels for sulfentrazone (see Table 3.0.1 in Section 3.0).

3. Exposure Science Advisory Council (ExpoSAC) Policy #9.1.

4. Dermal Dose = Dermal Unit Exposure (ug/lb ai) x CF (0.001 mg/ug) x Application Rate (lb ai/acre) x Area Treated (A/day) / BW (69 kg).

5. Dermal MOE = Dermal NOAEL (100 mg/kg/day)/Dermal Dose (mg/kg/day).

6. Inhalation Dose = Inhalation Unit Exposure (ug/lb ai) x CF (0.001 mg/ug) x Application Rate (lb ai/acre) x Area Treated (A/day) / BW (69 kg).

7. Inhalation MOE = Inhalation NOAEL (10 mg/kg/day) / Inhalation Dose (mg/kg/day).

8. Dermal Risk Index = Dermal MOE / Dermal LOC. Dermal LOC = 100.

9. Inhalation Risk Index = Inhalation MOE / Inhalation LOC. Inhalation LOC = 1000.

10. ARI = 1 / ((1 ÷ Dermal Risk Index) + (1 ÷ (Inhalation Risk Index)). No R = no respirator.
Sulfentrazone Human-Health Risk Assessment DP No. 389082

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Table 9.1.2. Short-/Intermediate-Term Occupational Exposure and Risk Estimates for Dry Bulk Fertilizer Use of Sulfentrazone. 

Exposure Scenario

Dermal 

Unit 

Exposure

(ug/lb ai)1

Inhalation 

Unit 

Exposure

(ug/lb ai)1

Applicati

on Rate2

Amount 

Treated 

Daily3

Dose (mg/kg/day)4,5 MOE6,7

Dermal Risk 

Index8

Inhalation 

Risk Index9 ARI10

Dermal Inhalation

Dermal 

(LOC = 

100)

Inhalation 

(LOC = 

1000)

Mixer/Loader Dry Flowables

Commercial 

Impregnation of Dry 

Bulk Fertilizers

9.8 

(closed 

system)

0.24 

(closed 

system)

3.75 lb 

ai/ton

960 tons 0.51 0.013 200 800 2 (closed 

system)

0.8 (closed 

system)

0.57 (closed 

system

On-farm 

Impregnation of Dry 

Bulk Fertilizers

Baseline: 

227

Baseline: 

8.96

0.375 lb 

ai/A

160 A 0.20 0.0078 510 1,300 Baseline: 5.1 Baseline: 1.3 Baseline: 1

80 A 0.099 0.0039 1,000 2,600 Baseline: 10 Baseline: 2.6 Baseline: 2.1

Mixer/Loader Liquids

Commercial 

Impregnation of Dry 

Bulk Fertilizers

8.6 

(closed 

system)

0.083 

(closed 

system)

3.75 lb 

ai/ton

960 tons 0.45 0.0043 220 2,300 2.2 (closed 

system)

2.3 (closed 

system)

1.1 (closed 

system

On-farm 

Impregnation of Dry 

Bulk Fertilizers

Baseline: 

220

Baseline: 

0.219

0.375 lb 

ai/A

160 A 0.19 0.00019 520 53,000 Baseline: 5.2 Baseline: 53 Baseline: 4.7

80 A 0.096 0.000095 1,000 110,000 Baseline: 10 Baseline: 110 Baseline: 9.2

Applicator

Commercial 

Impregnation of Dry 

Bulk Fertilizers

Baseline: 

9.9

Baseline: 

1.2

0.375 lb 

ai/A

320 0.017 0.0021 5,800 4,800 Baseline: 58 Baseline: 4.8 Baseline: 4.4

160 0.0086 0.0010 12,000 9,600 Baseline: 120 Baseline: 9.6 Baseline: 8.9

On-farm 

Impregnation of Dry 

Bulk Fertilizers

160 0.0086 0.0010 12,000 9,600 Baseline: 120 Baseline: 9.6 Baseline: 8.9

80 0.0043 0.00052 23,000 19,000 Baseline: 230 Baseline: 19 Baseline: 18

1. Based on “Occupational Pesticide Handler Unit Exposure Surrogate Reference Table” (September 26, 2011); includes data from PHED/ORETF/AHETF. Closed mixing/loading assumed for 

commercial impregnation of dry bulk fertilizer. Open mixing/loading assumed for on-farm impregnation of dry bulk fertilizer. Exposure values for granular application via open cab solid broadcast 

spreader used as surrogate for application of impregnated dry bulk fertilizer.

2. Based on proposed labels for sulfentrazone (see Table 3.0.1 in Section 3.0).

3. (ExpoSAC) Policy #9.1 and industry information.

4. Dermal Dose = Dermal Unit Exposure (ug/lb ai) x CF (0.001 mg/ug) x Application Rate (lb ai/acre or lb ai/ton) x Area Treated or Amount Handled (A/day or tons/day) / BW (69 kg).

5. Dermal MOE = Dermal NOAEL (100 mg/kg/day)/Dermal Dose (mg/kg/day).

6. Inhalation Dose = Inhalation Unit Exposure (ug/lb ai) x CF (0.001 mg/ug) x Application Rate (lb ai/acre or lb ai/ton) x Area Treated or Amount Handled (A/day or tons/day) /BW (69 kg).

7. Inhalation MOE = Inhalation NOAEL (10 mg/kg/day)/ Inhalation Dose (mg/kg/day).

8. Dermal Risk Index = Dermal MOE / Dermal LOC. Dermal LOC = 100.

9. Inhalation Risk Index = Inhalation MOE / Inhalation LOC. Inhalation LOC = 1000.

10. ARI = 1 / ((1 ÷ Dermal Risk Index) + (1 ÷ (Inhalation Risk Index)).
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9.2 Short-/Intermediate-Post-application Risk

9.2.1 Dermal Post-application Risk

Most of the proposed uses for sulfentrazone are soil-directed preplant or preemergent uses where 

no crop foliage is present. Currently, HED has no transfer coefficients or other data to assess 

post-application dermal exposures to soil by occupational workers. In general, such exposures 

are considered to be negligible. Therefore, for the proposed soil-directed uses, post-application 

exposures and risks to occupational workers were not assessed. 

The proposed use on non-grass animal feed crops, which includes alfalfa, does allow for 

applications in-season between cuttings. The proposed labels recommend that applications are 

made as soon as possible after cuttings and up to 6 inches of re-growth; therefore, a postapplication assessment has been conducted for activities associated with early season alfalfa. 

Transfer coefficients of 1,100 and 1,900 cm2/hr for scouting and hand set irrigation, respectively, 

along with default assumptions with respect to the fraction available for transfer and residue 

dissipation were used to estimate post-application exposures. 

A summary of the post-application MOEs and respective reentry intervals is provided in Table 

9.2.2. The short- and intermediate-term post-application assessments for alfalfa resulted in 

MOEs of 100 or greater on “day 0” (immediately after application) for all exposure activities and 

are not of concern. 

Table 9.2.2. Summary of Short- and Intermediate-Term Occupational Post-application Risk Estimates for 

Sulfentrazone.

Crop/Site

Transfer 

Coefficient 

(cm2/hr)

Application Rate 

(lb ai/A)

DFR on Day 0 

(ug/cm2)

1

Day 0 MOE2 Day X at which 

MOE ≥ LOC

ST and IT ST and IT

Alfalfa 1,100

0.375 1.052

750 0

1,900 430 0

1. DFR = AR x F x (1-D)t x 4.54E8 μg/lb x 2.47E-8 acre/cm2.

2. MOE = POD (NOAEL, 100 mg/kg/day) / Daily Dermal Dose. Daily Dermal Dose = [DFR (μg/cm2) x TC x 0.001 mg/μg x 8 hrs/day] body 

weight (69 kg adult). 

Short- and intermediate-term post-application risk estimates were not a concern on day 0 (12 

hours following application) for all post-application activities. Therefore, the REI is based on 

the acute toxicity of sulfentrazone. Typically, under the Worker Protection Standard (WPS) for 

agricultural pesticides, active ingredients classified as Acute III or IV for acute dermal, eye 

irritation and primary skin irrigation are assigned a 12-hour REI. Therefore, the WPS interim 

REI of 12 hours is adequate to protect agricultural workers from post-application exposures to 

sulfentrazone. 

9.2.2 Inhalation Post-application Risk

Based on the Agency's current practices, a quantitative occupational post-application inhalation 

exposure assessment was not performed for sulfentrazone at this time. However, there are 

multiple potential sources of post-application inhalation exposure to individuals performing postapplication activities in previously treated fields. These potential sources include volatilization 
Sulfentrazone Human-Health Risk Assessment DP No. 389082

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of pesticides and resuspension of dusts and/or particulates that contain pesticides. The Agency 

sought expert advice and input on issues related to volatilization of pesticides from its FIFRA 

SAP in December 2009. The Agency received the SAP’s final report on March 2, 2010 

(http://www.epa.gov/scipoly/SAP/meetings/2009/120109meeting.html). The Agency is in the 

process of evaluating the SAP report as well as available post-application inhalation exposure 

data generated by the Agricultural Reentry Task Force and may, as appropriate, develop policies 

and procedures, to identify the need for and, subsequently, the way to incorporate occupational 

post-application inhalation exposure into the Agency's risk assessments. If new policies or 

procedures are put into place, the Agency may revisit the need for a quantitative occupational 

post-application inhalation exposure assessment for sulfentrazone. 

10.0 References

Occupational and Residential Exposure Memo: K. Lowe, 17-MAY-2012, D389974;

Residue Chemistry Memo: G. Kramer, 14-JUN-2012; D389972;

Drinking Water Memo: M. Barrett, 03-APR-2012; D39377 and D397770;

Dietary Memo: J. Van Alstine, 14-JUN-2012; D389973; 

HASPOC Memo: D. Smegal, 02-MAR-2012; TXR # 0050684; and

Re-Classification of Peer-Reviewed Developmental Neurotoxicity Study in Rats: C. Rodriguez, 

19-DEC-2011; D389975.

cc: J. Van Alstine (RAB1), G. Kramer (RAB1), K. Lowe (RAB1), C. Rodriguez (RAB1)

RDI: Branch (5/2/12); Dana Vogel (5/10/12)

J. L. Van Alstine:S10951:PY-S:(703)603-8866:7509P:RAB1
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Appendix A. Toxicology Profile

Table A.1. Acute Toxicity Profile – Sulfentrazone.

Guideline 

No. Study Type MRID(s) Results Toxicity Category

870.1100 Acute oral [rat] 41911605 LD50 = 2855 (M & F) mg/kg III

870.1200 Acute dermal [mice] 41911606 LD50 = 711 (M & F) mg/kg III

870.1200 Acute dermal 42286400 LD50 > 2000 mg/kg/day III

870.1300 Acute inhalation [rat] 42471002 4-hour, whole body exposure; LC50 > 4.13 

mg/L

III

870.2400 Acute eye irritation 

[rabbit]

41911608 Corneal opacity, iritis, diffuse irritation 

within 24, clearing by day 4

III

870.2500 Acute dermal irritation 

[rabbit]

41911609 Non-irritating IV

870.2600 Skin sensitization [Guinea 

Pig]

41911610 Not a Dermal Sensitizer N/A

Table A.2. Toxicity Profile for Sulfentrazone

Guideline No./

Study Type

MRID No. (year)/Classification/ 

Doses Results

870.3100

90-Day oral toxicity (rat)

43004601 (1990)

Acceptable/Guideline

0, 300, 1000, 3000, & 7000 ppm,

M: 0, 3.3, 6.7, 19.9, 65.8, 199.3, 

& 534.9 mg/kg/day

F: 0, 4, 7.7, 23.1, 78.1, 230.5, & 

404.3 mg/kg/day

Systemic Toxicity NOAEL = 19.9 mg/kg/day in males 

and 23.1 mg/kg/day in females.

Systemic Toxicity LOAEL = 65.8 mg/kg/day in males 

and 78.1 mg/kg/day in females, based on clinical signs of 

anemia (reduced hematocrit, hemoglobin, mean cell 

volume, and mean cell hemoglobin values during 

treatment).

870.3100

90-Day oral toxicity (mice)

43616517 (1993)

Acceptable/Guideline

0, 50, 100, 300, 550, 1000, & 

3000 ppm

M: 0, 10.3, 17.8, 60, 108.4, & 

194.4 mg/kg/day

F: 0, 13.9, 29, 79.8, 143.6, & 

257 mg/kg/day

Systemic Toxicity NOAEL = 60 mg/kg/day in males and 

79.8 mg/kg/day in females.

Systemic Toxicity LOAEL = 108.4 mg/kg/day in males 

and 143.6 mg/kg/day in females, based on decreased 

body weights, body-weight gains, red blood cells, 

hemoglobin, hematocrit, and severity of splenic 

micropathology (increased incidence and severity of 

extramedullary hematopoiesis). Four-week recovery 

period reversed all the treatment related effects except 

extramedullary hematopoiesis; however, severity was 

reduced.

870.3150

90-Day oral toxicity (dog)

42932102 (1992)

Acceptable/Guideline

0, 300, 800 & 2000 ppm

M/F: 0/0, 10/10, 28/28, & 57/73

mg/kg/day

Systemic Toxicity NOAEL = 28 mg/kg/day for males 

and females.

Systemic Toxicity LOAEL = 57/73 mg/kg/day (M/F), 

based on decreased body weights (7-10%) and bodyweight gains during first 5 weeks of study; decreased 

hemoglobin, hematocrit, mean cell volume, mean cell 

hemoglobin and mean cell hemoglobin concentration, 

and increased absolute liver weights and alkaline 

phosphatase levels, and microscopic changes in the liver 

and spleen (pigmented sinusoidal microphages in the 

liver, swollen centrilobular hepatocytes and pigmented 

reticuloendothelial cells in the spleen).

870.3200

28-Day dermal toxicity 

(rabbit)

44248301 (1996)

Acceptable/Guideline

0, 10, 30, 100, 300, & 1000 

mg/kg/day

Systemic and Dermal Toxicity NOAEL = 1000 

mg/kg/day (highest dose tested or HDT).

Systemic and Dermal Toxicity LOAEL was not 

established.

870.3700a

Prenatal Developmental (rat)

42932104 (1992)

Acceptable/Guideline

0, 1, 10, 25, & 50 mg/kg/day

Maternal NOAEL = 25 mg/kg/day.

Maternal LOAEL = 50 mg/kg/day, based upon increased 

relative splenic extramedullary hematopoiesis.

Developmental NOAEL = 10 mg/kg/day.

Developmental LOAEL = 25 mg/kg/day, based upon 

decreased mean fetal weights, and retardation in skeletal 
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Table A.2. Toxicity Profile for Sulfentrazone

Guideline No./

Study Type

MRID No. (year)/Classification/ 

Doses Results

development evidenced by an increased number of litters 

with any variation and by decreased number of caudal 

vertebral and metacarpal ossification sites.

870.3700

Prenatal developmental (rat)

43651003 (1992)

Acceptable/Non-Guideline

0, 25, & 50 mg/kg/day

Study was conducted to evaluate 

external and cardiac 

abnormalities.

Maternal NOAEL = 25 mg/kg/day.

Maternal LOAEL = 50 mg/kg/day, based on decreased 

mean body weights during gestation, and decreased litter 

size.

Developmental NOAEL = 25 mg/kg/day.

Developmental LOAEL = 50 mg/kg/day, based on 

significant reductions in the number of implantations and 

percentage of live fetuses, increase in the percentage of 

early resorptions, and decreased fetal body weights.

Supplemental study to the 1992 Developmental-Toxicity 

Study in Rats (MRID 42932104)

870.3700

Prenatal dermal 

developmental (rat)

MRID 42932105 (1992)

Acceptable/Guideline

0, 5, 25, 50, 100, & 250 

mg/kg/day

Maternal NOAEL >250 mg/kg/day.

Maternal LOAEL was not established.

Developmental NOAEL = 100 mg/kg/day.

Developmental LOAEL = 250 mg/kg/day, based on 

decreased fetal body weight; increased incidence of fetal 

variations: hypoplastic or wavy ribs, incompletely 

ossified lumbar vertebral arches, and incompletely 

ossified ischia or pubis; and reduced number of thoracic 

vertebral and rib ossification sites.

870.3700b

Prenatal Developmental 

(rabbit)

MRID 42932106 (1993)

Acceptable/Guideline

0, 100, 250, & 375 mg/kg/day

Maternal NOAEL = 100 mg/kg/day.

Maternal LOAEL = 250 mg/kg/day, based on increased

abortions, clinical signs (hematuria and decreased feces), 

and reduced body-weight gain.

Developmental NOAEL = 100 mg/kg/day.

Developmental LOAEL = 250 mg/kg/day, based on 

increased resorptions, decreased live fetuses per litter, 

and decreased fetal weights.

870.3800

2-Generation reproduction 

and fertility effects (rat)

43345408 (1994)

Acceptable/Guideline

0, 200, 500, & 700 ppm

M/F: 0, 14/16, 33/40, & 46/56 

mg/kg/day

Parental Toxicity NOAEL =14 (M) and 16 (F) 

mg/kg/day.

Parental Toxicity LOAEL = 33 (M) and 40 (F) 

mg/kg/day based on decreased maternal body 

weight/body-weight gain during gestation in both 

generation (P & F1) and reduced premating body-weight 

gain in second-generation (F1) males.

Reproductive Toxicity NOAEL = 14 (M) and 16 (F) 

mg/kg/day.

Reproductive Toxicity LOAEL = 33 (M) and 40 (F) 

mg/kg/day, based on increased duration of gestation in 

females and degeneration and/or atrophy of the germinal 

epithelium of the testes and oligospermia and intratubular 

degenerated seminal material in the epididymis of F1

males.

Offspring Toxicity NOAEL = 14 (M) and 16 (F) 

mg/kg/day.

Offspring Toxicity LOAEL = 33 (M) and 40 (F) 

mg/kg/day, based on reduced prenatal viability (fetal & 

litter), reduced litter size, increased no. of stillborn pups, 

reduced pup and litter postnatal survival and decreased 

pup body weights throughout lactation.

870.3800

1-Generation reproduction 

and fertility effects (rat)

43869101(1995)

Acceptable/Nonguideline

0, 50, 100, 200, & 500 ppm

F0 M/F: 0, 3.9/4.1, 7.8/13.4, 

Systemic/Developmental Toxicity NOAEL = 20 (F) 

mg/kg/day.

Systemic/Developmental Toxicity LOAEL = 51 (F) 

mg/kg/day, (F1females), based on decrease in pre-mating 
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Table A.2. Toxicity Profile for Sulfentrazone

Guideline No./

Study Type

MRID No. (year)/Classification/ 

Doses Results

16/16, & 40/43 mg/kg/day

F1 M/F: 0/0, 4.5/5.0, 9.2/10.1, 

18/20, & 45/51 mg/kg/day

body-weight gain (10%).

Offspring and Reproductive Toxicity NOAEL = 16

mg/kg/day (M/F) mg/kg/day.

Offspring and Reproductive Toxicity LOAEL F1 = 40 

(M/F) mg/kg/day, based on reduced gestation day-20 

fetal weights; decreased postnatal day 0, 4, and 7 pup 

weights; decreased pup survival; delayed vaginal 

patency; reduced epididymal, prostate, and testicular 

weights. Additional information supports the conclusions 

reached in the 2-generation reproduction study (MRID 

43345408).

870.4100b

Chronic toxicity (dog)

43345406 (1994)

Acceptable/Guideline

0, 300, 800, and 1800 ppm

M/F: 0, 9.9/10.4, 24.9/29.6, & 

61.2/61.9 mg/kg/day

Systemic Toxicity NOAEL = 24.9/29.6 mg/kg/day for 

males/and females.

Systemic Toxicity LOAEL = 61.2/61.9 mg/kg/day (M/F), 

based upon compensated normochromic microcytosis.

870.4200

Carcinogenicity rodents 

(mouse)

43345407 (1994)

Acceptable/Guideline

0, 300, 600, 1000, & 2000 ppm

M/F: 0, 46.6/58.0, 93.9/116.9, 

160.5/198.0 & 337.6/407.1 

mg/kg/day

Systemic Toxicity NOAEL = 93.9 mg/kg/day for males 

and 116.9 mg/kg/day for females.

Systemic Toxicity LOAEL = 160.5 mg/kg/day for males 

and 198.0 mg/kg/day for females, based on dose-related 

decreases in hemoglobin and hematocrit by study 

termination.

No evidence of carcinogenicity.

870.4300

Combined chronic 

toxicity/carcinogenicity 

rodents (rat)

43345409 (1994)

Acceptable/Guideline

M: 0, 600, 1000, 2000, & 3000 

ppm

F: 0, 300, 600, 1000 & 2000 

ppm

M/F: 0/0, 24.3/20, 40/36.4, 

82.8/67, & 123.5/124.7 

mg/kg/day

Systemic Toxicity NOAEL = 40 mg/kg/day for males 

and 36.4 mg/kg/day for females.

Systemic Toxicity LOAEL = 82.8 mg/kg/day for males 

and 67 mg/kg/day for females, based on dose-related 

decreased body weights (11 & 19%), body-weight gains 

(13 & 26%), food consumption (13 & 19%), hemoglobin, 

hematocrit, mean cell volume, and mean cell hemoglobin. 

Increased nucleated red blood cells and reticulocytes in 

bone of females at 124.7 mg/kg/day.

No evidence of carcinogenicity.

870.5100

Gene Mutation: Ames assay

Gene Mutation: HGPRT

41911611 (1986)

Acceptable/Guideline

Salmonella typhimurium strains

TA1535, TA1538, TA1537, 

TA98, and TA100 were exposed 

to sulfentrazone technical 

(95.5%) at concentrations of 

100-10,000 ug/plate with or 

without S9 activation (both 

trials).

No evidence of compound-induced cytotoxicity was 

evident either in presence or in absence of S9 activation. 

The positive controls induced the expected mutagenic 

responses in the appropriate tester strain. Sulfentrazone 

was considered not mutagenic under any test condition.

870.5300

In vitro mammalian cell gene 

mutation assay (mouse 

lymphoma)

43004604 (1992)

Acceptable/Guideline

Mouse lymphoma (L5178Y 

TK+/- CHO) cells were exposed 

to sulfentrazone technical 

(94.2%) in non-activated dose 

ranges of 424-1308 ug/mL (Trial 

1) and 1308-3000 ug/mL (Trial 

2); With S9 activation dose 

ranges of 424-1407 ug/mL (Trial 

1) and 915-1800 ug/mL (Trial 

2).

In a forward gene mutation assay, sulfentrazone at 

precipitating levels were equivocally positive in the 

absence of S9 activation. This response was not repeated 

at doses up to 1800 g/mL in the presence of S9 

activation.

870.5395 43004605 (1992) The test was negative in mice administered single 
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Table A.2. Toxicity Profile for Sulfentrazone

Guideline No./

Study Type

MRID No. (year)/Classification/ 

Doses Results

Mammalian erythrocyte 

micronucleus test

Acceptable/Guideline

Groups of 5 male and 5 female 

ICR mice received single 

intraperitoneal injection of 85, 

170, and 340 mg/kg 

sulfentrazone technical (94.2%). 

Test material was administered 

in corn oil and bone marrow 

cells harvested at 24, 48, and 72 

hours post-dosing. 

Cyclophosphamide at 30 mg/kg 

was used as positive control.

intraperitoneal doses of 85-340 mg/kg. The 340 mg/kg 

dose was estimated to be approximately 80% of the 

LD50/7. No evidence of a cytotoxic effect on the target 

organ and no significant increase in the frequency of 

micronucleated polychromatic erythrocytes in bone 

marrow cells.

870.5450

Dominant lethal

assay - rodent

44248302 (1996)

Acceptable/Guideline

In dominant lethal assay, male 

rats were dosed at 0, 100, 225, or 

450 mg/kg/day for 5 days, and 

mated to untreated females 

sequentially for 10 weeks to 

determine the level of fetal 

deaths due to dominant lethal 

mutations.

There were no significant differences from negative 

controls in the proportion of early dead: total implants, 

and (total) dead: total implants. Based on the results, 

sulfentrazone is considered negative for inducing 

dominant lethal mutations in pre-meiotic, meiotic, and 

post-meiotic germ cells of male rats under conditions of 

this assay up to the estimated maximum tolerable dose 

(MTD).

870.6200 Acute 

Neurotoxicity Study

43345405 (1994)

Acceptable/Guideline

0, 250, 750, & 2000 mg/kg

Systemic Toxicity NOAEL = 250 mg/kg/day.

Systemic Toxicity LOAEL = 750 mg/kg/day, based upon 

increased incidence of clinical signs, FOB findings, and 

decreased motor activity which was reversed by day 14 

post dose.

No evidence of neuropathology at any dose.

870.6200 Subchronic 

Neurotoxicity Study

43345405 (1994)

Acceptable/Guideline

0, 500, 2500, or 5000 ppm (0/0, 

30/37, 150/180, or 265/292 

mg/kg/day [M/F])

NOAEL = 500 ppm (30/37 mg/kg/day).

LOAEL = 2500 ppm (150/180 mg/kg/day) based on 

increased incidence of clinical signs (M&F), decreased 

BW, BWG, and FC (F), and increased motor activity at 

week 13 only (F).

No evidence of neuropathology at any dose.

870.7485

Metabolism and

pharmacokinetics

(rat)

43345410 (1994)

Acceptable/Guideline

Phenyl -

14C - sulfentrazone 

(98% pure.) was administered to 

Sprague-Dawley rats (5 

animals/sex/dose) by gavage as a 

single dose at levels of 50 and 

500 mg/kg, or as a single dose of 

50 mg/kg following a 14-day 

pretreatment with nonradioactive sulfentrazone (50 

mg/kg/day).

Sulfentrazone was readily absorbed and 84 to 104% of 

the administered dose was excreted in urine and feces 

within 72 hours. There were no major sex differences in 

the pattern of excretion. Almost all the radioactivity in 

the urine was HMS (84-104% of the administered dose). 

In the feces, HMS accounted for 1.26-2.55% of the 

administered dose. The proposed metabolic pathway 

appeared to be conversion of the parent compound 

mainly to HMS (excreted in the urine). A small amount 

of HMS was also converted to sulfentrazone 3-carboxylic 

acid (excreted in the urine and feces).

Published literature 47749201 (2009)

De Castro, et al., (2007)

Acceptable/non-guideline

0, 25, or 50 mg/kg bw/day

Dose-dependent, statistically significant delayed ear 

opening, decreased grip response and rearing frequency, 

and increased surface righting reflex reaction time 

observed at ≥25 mg/kg/day; no effect on maternal body 

weight (only parameter tested in dams) during gestation. 

The results of this non-guideline study were published in 

the open literature. Due to limitations in study conduct 

and reporting of the statistical analysis, the study is of 

limited value in risk assessment. 
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Appendix B. Physical/Chemical Properties

Table B.1. Physicochemical Properties of Technical Grade Sulfentrazone.

Parameter Value Reference

Melting range 120-122 oC DP# 288712, 3/6/03, G. 

Kramer, G. Reddy, and L. 

Liu

pH 4.78 at 23 oC

Density 0.53 g/cm3

Water solubility 4.0 x 102μg/g

Solvent solubility 18.6% w/w in acetonitrile

Vapor pressure 8 x 10-10 mm Hg

Dissociation constant, pKa 6.56

Octanol/water partition coefficient, 

Log(KOW)

1.49 at pH 5

UV/visible absorption spectrum Not available
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Appendix C. Summary of Residue Data

Table C.1. Summary of Residue Data from Turnip Crop Field Trials with Sulfentrazone.

Commodity Analyte

Total App. 

Rate

(lb ai/A)1

PHI

(days)

Residue Levels (ppm sulfentrazone equivalents)2

n

Sample 

Min.

Sample 

Max. LAFT3 HAFT3 Median Mean

Std. 

Dev.

Turnip (proposed use = 0.25 lb ai/A application rate, 46- to 60-day PHI)

Turnip

tops

Combined

Residues

0.200-0.206 46-60 5 <0.15 <0.46 0.15 0.34 0.15 0.20 0.08

0.249-0.298 46-60 5 <0.15 <0.44 0.15 0.31 0.15 0.20 0.07

Turnip

roots

Combined

Residues

0.200-0.206 46-60 5 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

0.249-0.298 46-60 5 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

1

 Total application rate includes application of both formulations (4 lb/gal SC and 75% WG formulation).

2

 Except for sample min/max, values reflect per-trial averages; n = no. of field trials. For calculation of median, mean, and 

standard deviation, the LOQ (0.05 ppm for all analytes) was used for any results reported as <LOQ. N/A = not applicable.

3

 LAFT = lowest average field trial; HAFT = highest average field trial.

Table C.2. Summary of Residue Data from Rhubarb Crop Field Trials with Sulfentrazone.

Commodity Analyte

Total App. 

Rate 

(lb ai/A)

PHI

(days)

Residue Levels (ppm sulfentrazone equivalents)1

n

Sample 

Min.

Sample 

Max. LAFT2 HAFT2 Median Mean

Std. 

Dev.

Rhubarb (proposed use = 0.25 lb ai/A application rate, Postemergence just prior to plants breaking dormancy)

Rhubarb

petiole

Combined

Residues

0.252-0.264 78-85 3 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

1

 Except for sample min/max, values reflect per-trial averages; n = no. of field trials. For calculation of median, mean, and 

standard deviation, the LOQ (0.05 ppm for all analytes) was used for any results reported as <LOQ. N/A = not applicable.

2

 LAFT = lowest average field trial; HAFT = highest average field trial.

3

 Residues of the metabolites were not determined in parent equivalents; based on the structures of the parent and metabolites,

molecular-weight-conversion factors would be 0.96x for DMS and 1.04x for HMS, when values are >LOQ.

Table C.3. Summary of Residue Data from Wheat Crop Field Trials with Sulfentrazone.

Commodity Analyte

Total App. 

Rate (lb ai/A)

PHI

(days)

Residue Levels (ppm sulfentrazone equivalents)1

n

Sample 

Min.

Sample 

Max. LAFT2 HAFT2 Median Mean

Std. 

Dev.

Spring Wheat (proposed use = 0.188 ai/A application rate, 46-to 60-day PHI for forage, 120-day PHI for grain)

Wheat

forage

Combined

Residues

0.186-0.192 41-60 3 <0.15 <0.30 0.15 0.26 0.15 0.19 0.06

Wheat

hay

Combined

Residues

0.186-0.192 87-95 3 <0.15 <0.16 0.15 0.16 0.15 0.15 0.003

Wheat grain Combined

Residues

0.186-0.192 98-140 3 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

Wheat

straw

Combined

Residues

0.186-0.192 98-140 3 <0.15 <0.54 0.15 0.50 0.15 0.27 0.20

1 Except for sample min/max, values reflect per-trial averages; n = no. of field trials. For calculation of median, mean, and 

standard deviation, the LOQ (0.05 ppm for all analytes) was used for any results reported as <LOQ. N/A = not applicable.

2

 LAFT = lowest average field trial; HAFT = highest average field trial.

Table C.4. Summary of Residue Data from Tree Nuts Crop Field Trials with Sulfentrazone.

Commodity Formulation

Total App. 

Rate

(lb ai/A)

PHI 

(days)

Combined Residue Levels (ppm)1

n

Sample 

Min.

Sample 

Max. LAFT2 HAFT2 Median Mean

Std. 

Dev.

Tree Nuts (proposed use = 0.375 lb ai/A application rate, 3-day PHI)
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Table C.4. Summary of Residue Data from Tree Nuts Crop Field Trials with Sulfentrazone.

Commodity Formulation

Total App. 

Rate

(lb ai/A)

PHI 

(days)

Combined Residue Levels (ppm)1

n

Sample 

Min.

Sample 

Max. LAFT2 HAFT2 Median Mean

Std. 

Dev.

Almond, 

hulls

2 lb ai/gal SE 0.375-0.384 7 2 <0.15 <0.15 0.15 0.15 0.15 0.15 NA

75% DF 0.375 7 1 <0.15 <0.15 0.15 0.15 0.15 0.15 NA

4 lb ai/gal FlC 0.376-0.377 6-7 2 <0.15 <0.15 0.15 0.15 0.15 0.15 NA

Almond, 

nutmeat

2 lb ai/gal SE 0.375-0.384 7 2 <0.15 <0.15 0.15 0.15 0.15 0.15 NA

75% DF 0.375 7 1 <0.15 <0.15 0.15 0.15 0.15 0.15 NA

4 lb ai/gal FlC 0.377 6-7 2 <0.15 <0.15 0.15 0.15 0.15 0.15 NA

Pecan, 

nutmeat

2 lb ai/gal SE 0.374-0.375 7 2 <0.15 <0.15 0.15 0.15 0.15 0.15 NA

75% DF 0.377-0.382 7-8 2 <0.15 <0.15 0.15 0.15 0.15 0.15 NA

4 lb ai/gal FlC 0.373 7 1 <0.15 <0.15 0.15 0.15 0.15 0.15 NA

1 Except for sample min/max, values reflect per-trial averages; n = no. of field trials. For calculation of median, mean, and 

standard deviation, the LOQ (0.05 ppm for all analytes) was used for any results reported as <LOQ. N/A = not applicable. 

Residues of the metabolites were not determined in parent equivalents.

2 LAFT = lowest-average-field-trial; HAFT = highest-average-field-trial.

Table C.5. Summary of Residue Data from Citrus Crop Field Trials with Sulfentrazone.

Commodity Analyte

Total App. 

Rate

(lb ai/A)

PHI

(days)

Residue Levels (ppm)1

n

Sample 

Min.

Sample 

Max. LAFT2 HAFT2 Median Mean

Std. 

Dev.

Citrus (proposed use = 0.375 lb ai/A application rate, 3-day PHI)

Orange, 

Fruit

Combined 0.373-0.377 6-7 12 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

Lemon, Fruit Combined 0.373-0.382 7-8 5 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

Grapefruit, 

Fruit

Combined 0.373-0.377 7-8 6 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

1

 Except for sample min/max, values reflect per-trial averages; n = no. of field trials. For calculation of median, mean, and 

standard deviation, the LOQ (0.05 ppm for all analytes) was used for any results reported as <LOQ. N/A = not applicable. 

Residues of the metabolites were not determined in parent equivalents.

2

 LAFT = lowest-average-field-trial; HAFT = highest-average-field-trial.

Table C.6. Summary of Residue Data from Berry and Small Fruit Crop Field Trials with Sulfentrazone.

Commodity Formulation

Total App. 

Rate (lb ai/A)

PHI 

(days)

Combined Residue Levels (ppm)1

n

Sample 

Min.

Sample 

Max. LAFT2 HAFT2 Median Mean Std. Dev.

Berry and Small Fruit (proposed use = 0.375 lb ai/A application rate, 3-day PHI)

Grape, Fruit 2 lb ai/gal SE 0.373-0.376 6-8 3 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

75% DF 0.373-0.377 6-8 3 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

4 lb ai/gal FlC 0.371-0.386 6-8 3 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

Strawberry, 

Berry

2 lb ai/gal SE 0.371-0.377 7 2 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

75% DF 0.375 7 1 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

4 lb ai/gal FlC 0.372 7 1 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

Blueberry, 

Berry

2 lb ai/gal SE 0.372-0.382 7 2 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

75% DF 0.376 7 1 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

4 lb ai/gal FlC 0.382 7 1 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

Blackberry, 

Berry

2 lb ai/gal SE 0.379 7 1 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

75% DF 0.376 7 1 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

Raspberry, 75% DF 0.374 7 1 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A
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Table C.6. Summary of Residue Data from Berry and Small Fruit Crop Field Trials with Sulfentrazone.

Commodity Formulation

Total App. 

Rate (lb ai/A)

PHI 

(days)

Combined Residue Levels (ppm)1

n

Sample 

Min.

Sample 

Max. LAFT2 HAFT2 Median Mean Std. Dev.

Berry 4 lb ai/gal FlC 0.379 7 1 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

Elderberry, 

Berry

2 lb ai/gal SE 0.375 7 1 <0.15 0.1506 0.1503 0.1503 0.1503 0.1503 N/A

4 lb ai/gal FlC 0.374 7 1 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

Kiwifruit, 

Fruit

2 lb ai/gal SE 0.378 7 1 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

75% DF 0.377 7 1 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

4 lb ai/gal FlC 0.391 7 1 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

1

 Except for sample min/max, values reflect per-trial averages; n = no. of field trials. For calculation of median, mean, and 

standard deviation, the LOQ (0.05 ppm for all analytes) was used for any results reported as <LOQ. N/A = not applicable. 

Residues of the metabolites were not determined in parent equivalents.

2

 LAFT = lowest-average-field-trial; HAFT = highest-average-field-trial.

Table C.7. Summary of Residue Data from Clover and Alfalfa Crop Field Trials with Sulfentrazone.

Commodity Analyte

Treatment 

Type

Total 

Rate

(lb ai/A)

PHI 

(days)

Residue Levels (ppm)1

n

Sample 

Min.

Sample 

Max. LAFT2 HAFT2 Median Mean Std. Dev.

Crop Group 18: Nongrass Animal Feeds (proposed use = 0.375 ai/A application rate, 21-day PHI for forage/hay, 41-day PHI 

for seed)

Clover 

Forage

Total 

Residues

Single 0.375 21 3

3

<0.266 3.85 0.279 3.66 1.18 1.71 1.75

Clover Hay Total 

Residues

Single 0.375 21 3

3

<0.772 17.6 0.797 15.7 3.68 6.73 7.90

Clover 

Seed

Total 

Residues

Single 0.366-

0.375

41-124 5 <0.15 1.71 0.15 1.64 0.189 0.484 0.648

Alfalfa 

Forage

Total 

Residues

Single 0.375 21-23 9 <0.199 1.30 0.200 1.24 0.315 0.502 0.344

Alfalfa Hay Total 

Residues

Single 0.375 21-23 9 <0.540 3.64 0.549 3.58 1.72 1.803 1.19

Alfalfa 

Seed

Total 

Residues

Single 0.369-

0.375

71-161 5 <0.15 <0.15 0.15 0.15 0.15 0.15 N/A

1

 Except for sample min/max, values reflect per-trial averages; n = no. of field trials. For calculation of median, mean, and 

standard deviation, the LOQ (0.05 ppm for all analytes) was used for any results reported as <LOQ. N/A = not applicable. 

2

 LAFT = lowest-average-field-trial; HAFT = highest-average-field-trial.

3

 Does not include clover forage and hay samples from Trial 04. Residues from this trial were determined by the petitioner to be 

statistical outliers. These residues were 10x and 6x higher than the next highest residue of forage and hay, respectively, from 

other trials that used the same pattern of test substance use.

4

 Does not include alfalfa forage and hay samples from Trial 17. Residues from this trial were determined by the petitioner to be 

statistical outliers. These residues were 5x higher than the next highest residue of forage and hay from other trials that used the 

same pattern of test substance use.

Sunflower subgroup 20B

No new sunflower subgroup 20B field trial data were submitted. An individual tolerance has 

been established for the combined residues of sulfentrazone and its metabolites HMS and DMS 

in/on sunflower seed at 0.20 ppm [40 CFR §180.498(a)(2)]. The previously submitted residue 

data for sunflower seed are adequate to support the proposed crop subgroup tolerance for the 

combined residues of sulfentrazone, DMS, and HMS of 0.20 ppm in/on sunflower, subgroup 

20B.
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Vegetable Soybean (edamame)

From the Minutes of the 11/30/2011 ChemSAC Meeting:

“IR-4 has received a pesticide clearance request from the states of IL and WA for the use of 

herbicide sulfentrazone on vegetable soybean (edamame) to control perennial and annual 

broadleaf weeds and grasses. The proposed labeling is to apply sulfentrazone as a preemergence treatment. IR-4 Project is requesting that existing data for lima bean (succulent) 

and pea (succulent) be used for extrapolation for vegetable soybean (edamame), and 

thereby be used to set a sulfentrazone tolerance on vegetable soybean (edamame) at 0.15 

ppm.

A tolerance for the combined residues of sulfentrazone and its two metabolites is 

established at 0.15 ppm for pea, succulent, and bean, lima, succulent (CFR 180.498). 

Cultural practices and weed problems in succulent lima bean production are similar enough 

to vegetable soybean (edamame) production, and IR-4 is proposing that label rates and use 

pattern for sulfentrazone in vegetable soybean (edamame) will be the same as in succulent 

lima bean. No residues above the lowest level of method validation (LLMV) of 0.05 ppm 

were observed for sulfentrazone and two metabolites in any of the succulent pea or lima 

bean samples. 

It is reasonable to expect that residues of sulfentrazone in or on vegetable soybean 

(edamame) when applied as in succulent lima beans would not exceed the proposed 

tolerances of 0.15 ppm. Therefore, the ChemSAC approves the IR-4 proposal for 

establishment a tolerance of 0.15 ppm for the combined residues of sulfentrazone and its 

two metabolites in/on soybean, vegetable, succulent based on the existing sulfentrazone 

tolerance for pea, succulent and lima bean, succulent.”

Cowpea, Succulent (Tennessee only)

As the use pattern for cowpea is the same as that for lima bean (0.188 lb ai/A, preemergence), 

HED concludes that existing data for lima bean (succulent) can be extrapolated to cowpea, and 

thereby be used to set a tolerance for the combined residues of sulfentrazone, DMS, and HMS on 

cowpea, succulent at 0.15 ppm.

Lima Bean, Succulent (TN only)

IR-4 has requested to amend the current tolerances in 40 CFR 180.498 in or on bean, lima, 

succulent at 0.15 ppm by removing the tolerance from the table in Section (a)(2) and adding the 

tolerance to Section (c) Tolerances with regional registrations. As all four residue trials 

submitted to support this tolerance were conducted in TN (D287102, 1/10/03, G. Kramer), a 

regional registration is appropriate.
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Appendix D. Review of Human Research

This risk assessment relies in part on data from studies in which adult human subjects were 

intentionally exposed to a pesticide or other chemical. These data, which include studies from 

the PHED 1.1; the AHETF database; the Outdoor Residential Exposure Task Force (ORETF) 

database; and the ARTF database, are subject to ethics review pursuant to 40 CFR 26, have 

received that review, and are compliant with applicable ethics requirements. For certain studies, 

that review may have included review by the Human Studies Review Board. Descriptions of 

data sources as well as guidance on their use can be found at 

http://www.epa.gov/pesticides/science/handler-exposure-data.html and 

http://www.epa.gov/pesticides/science/post-app-exposure-data.html.