Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

MEMORANDUM

Date: 09/29/2008

Subject: Sulfentrazone. Section 3 Registration Request to Add New Uses on: Brassica, 

Head and Stem, Subgroup 5A; Brassica, Leafy Greens, Subgroup 5B; Melon, Subgroup 9A; 

Fruiting Vegetable, Group 8 and Okra; Pea, Succulent; Flax; Strawberry; and Tuberous and 

Corm Vegetable, Subgroup 1C. Summary of Analytical Chemistry and Residue Data.

PC Code: 129081 DP Barcode: D349321

Decision No.: 388050 Registration Nos: 279-3220 & 279-3189

Petition No.: 7E7308 Regulatory Action: Amended Section 3

Risk Assessment Type: NA Case No.: NA

TXR No.: NA CAS No.: 122836-35-5

MRID No.: see MRID Summary Table 40 CFR: §180.498

From: William D. Wassell, Chemist

Registration Action Branch 1 (RAB1)

Health Effects Division (HED, 7509P)

Through: George F. Kramer, Ph.D., Branch Senior Chemist

RAB1/HED (7509P)

To: Daniel Rosenblatt, RM 05

Registration Division (RD, 7505P) 

MRID Summary Table

MRID No. Study Type Comments

47311401 860.1500 broccoli New DER; 47311401.der.doc

47311402 860.1500 mustard greens New DER; 47311402.der.doc

47311403 860.1500 cantaloupe New DER; 47311403.der.doc

47311404 860.1500 pepper

47311405 860.1500 tomato

860.1520 tomato

New DERs; 47311404.der.doc (includes MRID 47311405) 

and 47311405.der.doc

47311406 860.1500 succulent pea New DER; 47311406.der.doc

47311407 860.1500 flax

860.1520 flax

New DERs; 47311407.de1.doc and 47311407.de2.doc

47311408 860.1500 strawberry New DER; 47311408.der.doc

This document was originally prepared under contract by Dynamac Corporation (2275 Research 

Boulevard, Suite 300; Rockville, MD 20850; submitted: 05/22/2008). This document has been 

reviewed by HED and revised to reflect current Office of Pesticide Programs (OPP) policies.
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Executive Summary

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 Interregional Research Project No. 4 (IR-4) has submitted a petition proposing the 

establishment of permanent tolerances for the combined residues of the herbicide 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-triazolyl)phenyl)methanesulfonamide)] and DMS [(N-2,4- dichloro-5-[4-(difluoromethyl)-4,5-dihydro5-oxo-1H-1,2,4-triazol-1-yl)phenyl)methanesulfonamide] in/on:

Brassica, head and stem, subgroup 5A*.....................0.20 ppm

Brassica, leafy greens, subgroup 5B...........................0.35 ppm

Melon, subgroup 9A ...................................................0.10 ppm

Vegetable, fruiting, group 8 ........................................0.05 ppm

Okra.............................................................................0.05 ppm

Pea, succulent..............................................................0.05 ppm

Flax .............................................................................0.05 ppm

Strawberry...................................................................0.05 ppm

Vegetable, tuberous and corm, subgroup 1C* ............0.15 ppm

* Individual tolerances are established for residues in/on cabbage at 0.20 ppm and potato at 0.15 ppm.

A tolerance is currently established under 40 CFR §180.498(a)(1) for the combined residues of 

sulfentrazone and its major metabolite, HMS, in/on soybean seed at 0.05 ppm. In addition, 

permanent tolerances are established under 40 CFR §180.498(a)(2) for the combined residues of 

sulfentrazone and its metabolites HMS and DMS in/on several food commodities; these 

established tolerances range from 0.15 ppm (various plant commodities) to 0.40 ppm (peanut 

meal). Time-limited tolerances for the combined residues of sulfentrazone and its metabolites 

HMS and DMS have been established under 40 CFR §180.498(b) in connection with Section 18 

Emergency Exemptions; these include tolerances for residues in/on bean, succulent-seed without 

pod (lima bean & cowpea) at 0.1 ppm with a 12/31/07 expiration date, flax seed at 0.2 ppm with 

a 12/31/10 expiration date, and strawberry at 0.60 ppm with a 12/31/10 expiration date. Finally, 

tolerances are established under 40 CFR §180.498(d) for inadvertent and indirect combined 

residues of sulfentrazone and its metabolites HMS and DMS in/on cereal grain (excluding sweet 

corn) bran, forage, grain, hay, hulls, stover, and straw at 0.1-0.6 ppm as a result of the application 

of sulfentrazone to growing crops.

There are no Mexican, Canadian or Codex maximum residue limits (MRLs) established for 

sulfentrazone in/on any of the subject crops; therefore, there are no compatibility issues to be 

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

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

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

requests the amendment of these EP labels to incorporate new uses on head and stem Brassica, 

leafy greens Brassica, fruiting vegetables including okra, melons, strawberry, succulent peas and 

beans, and flax. These EPs are proposed for: (i) preplant or preemergence applications on all of 

the above-listed crops at maximum seasonal rates of 0.1875-0.375 lb ai/A using ground or aerial 

equipment; and (ii) postemergence applications on fruiting vegetables at a maximum seasonal 

rate of 0.375 lb ai/A. No pre-harvest intervals (PHIs) were proposed for these crops.

The nature of the residue in soybeans as well as rotational crops is adequately understood. The 

HED Metabolism Committee has 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 (D226434, 6/14/96, G. 

Kramer). In addition, HED concluded that the results of the rotational crop metabolism studies 

may be translated to support preemergence uses on all types of crops (D220548, 3/13/96, G. 

Kramer). However, as the proposed use pattern on fruiting vegetables includes postemergence 

applications, metabolism data are not available to support this specific use pattern. HED is, 

therefore, recommending that all proposed uses should be limited to preemergence application 

only unless the petitioner is willing to submit new metabolism studies on fruiting vegetables 

reflecting postemergence application. However, as the enforcement method for plant 

commodities determines free and conjugated forms of the analytes, the tolerance expression 

should be revised to indicate the residues of concern are the combined residues of free and 

conjugated sulfentrazone, and its metabolites HMS and DMS.

The nature of the residue in livestock is adequately understood based on acceptable ruminant and 

poultry metabolism studies. Sulfentrazone per se and its metabolites HMS and DMS were 

identified as the residues of concern in meat, milk, poultry, and eggs. Based on established and 

proposed sulfentrazone tolerances and the results of livestock metabolism studies, conventional 

feeding studies and tolerances for livestock commodities are not required for the purpose of this 

petition only.

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 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 either a GC/XSD halogen-specific 

detector) method or a liquid chromatograph equipped with tandem mass spectrometers 
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(LC/MS/MS) method. The validated LOQ was 0.05 ppm for each analyte. These methods are 

adequate for data collection based on acceptable method validation and concurrent recovery data.

Pending submission of a revised Section F as specified in Table 15, adequate crop field trial data 

have been submitted for: broccoli, one of the representative commodities of head and stem 

Brassica (subgroup 5A); provided the proposed use directions (Section B) are modified, mustard 

greens, the sole representative commodity of Brassica leafy greens (subgroup 5B); peas 

(succulent and edible-podded); bell and non-bell peppers and tomatoes, the representative 

commodities of fruiting vegetables (group 8); cantaloupe, the sole representative commodity of 

melon subgroup (subgroup 9A); strawberries; and flax. The submitted data showed that the 

combined residues of sulfentrazone, DMS, and HMS were <0.15 ppm in/on mature commodities 

listed above following application(s) of a representative formulation of sulfentrazone according 

to the proposed crop use pattern. It is, however, noted that higher residues were observed in/on 

mustard green samples treated at <1.0x. The field trial data are supported by adequate storage 

stability data, and no corrections need to be applied to the observed residue levels. A revised 

Section B should be submitted to remove the proposed postemergence use on fruiting vegetables.

The previously reviewed data for potato, the representative commodity of tuberous and corm 

vegetables (subgroup 1C) may be used to support the requested use pattern for the subgroup. 

These data were submitted as part of PP# 2E6405 (D287102, 1/10/03, G. Kramer) and showed 

that the maximum combined residues of sulfentrazone and its metabolites HMS and DMS were 

0.077 ppm in/on potato tubers after a preemergence treatment at 1x.

The previously reviewed data for cabbage, another representative commodity of head and stem 

Brassica (subgroup 5A) may be used to support the requested use pattern for the subgroup. 

These data were submitted in conjunction with PP#1E6311 (D276111, 12/9/02, G. Kramer) and 

indicate that the combined residues of sulfentrazone, HMS, and SCA (quantitated as DMS) were 

<0.15-0.18 ppm and <0.15-0.17 ppm in/on cabbage heads with and without wrapper leaves, 

respectively, following application at 1x.

The submitted data for the fruiting vegetables may used to support the proposed use on okra.

The submitted flax and tomato processing studies are unacceptable since the studies did not 

conclusively demonstrate that sulfentrazone residues of concern will not concentrate in processed 

fractions as a result of the proposed use. Quantifiable residues were not detected in the RACs 

used for processing, and the field trials were conducted at only 1x (flax) or 2x (tomatoes) rates. 

Since phytotoxicity does not appear to be an issue, the processing studies need to be repeated 

using an exaggerated application rate (equal to the maximum theoretical concentration factor or 

5x, whichever is less).

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 ≥ 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.
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Analytical standards for sulfentrazone and its metabolites DMS and HMS are currently available 

at the EPA National Pesticide Standards Repository. However, the standards for sulfentrazone 

and its metabolite DMS will expire 10/1/2012 and 5/1/2012, respectively, and the standard for 

HMS has expired 4/1/2008.

Regulatory Recommendations and Residue Chemistry Deficiencies

HED has examined the residue chemistry database for sulfentrazone. There are no residue 

chemistry issues that would preclude granting a conditional registration for the requested uses 

pending submissions of: a revised Section B (see requirements under Directions for Use);

reference standard for the metabolite HMS (see requirements under Submittal of Analytical 

Reference Standards); and a revised Section F (see Table 15). Full and unconditional registration 

will be granted following submission of adequate flax and tomato processing studies. The 

proposed uses and the submitted data support the establishment of the following tolerances for 

the combined residues of free and conjugated sulfentrazone and its metabolites HMS and DMS 

in/on:

Brassica, head and stem, subgroup 5A.......................0.20 ppm

Brassica, leafy greens, subgroup 5B...........................0.40 ppm

Melon, subgroup 9A ...................................................0.15 ppm

Vegetable, fruiting, group 8 ........................................0.15 ppm

Okra.............................................................................0.15 ppm

Pea, succulent..............................................................0.15 ppm

Flax .............................................................................0.15 ppm

Strawberry...................................................................0.15 ppm

Vegetable, tuberous and corm, subgroup 1C..............0.15 ppm

A human-health risk assessment is forthcoming.

Note to RD: As the enforcement method for plant commodities determines free and conjugated 

forms of the analytes, the tolerance expression should be revised to indicate tolerances are 

established for combined residues of free and conjugated forms of sulfentrazone, and its 

metabolites HMS and DMS.

860.1200 Directions for Use

A revised Section B is required. The proposed label for Spartan®4F Herbicide (EPA Reg. No. 

279-3220), a 4 lb/gal FlC formulation, should be modified to correct the application rates listed 

as “dry ounces Spartan® Herbicide per acre” to “fluid ounces Spartan® Herbicide per acre.”

Also, as metabolism data are not available to support postemergence applications on fruiting 

vegetables, these proposed uses should be limited to preemergence application only.

Additionally, the proposed labels should be revised to specify a maximum single and seasonal 

application rate of 0.020 lb ai/A for Spartan®to Brassica leafy greens subgroup 5B as this rate is 

supported by the submitted crop field trial data for mustard greens. 
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860.1520 Processed Food and Feed

New flax and tomato processing studies should be submitted. Since phytotoxicity does not 

appear to be an issue, the requested processing studies should use an exaggerated application rate 

(equal to the maximum theoretical concentration factor or 5x, whichever is less).

860.1650 Submittal of Analytical Reference Standards

As the reference standard for the metabolite HMS has expired 4/1/2008, the petitioner must 

submit a new standard. 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

860.1550 Proposed Tolerances

A summary of recommended tolerances are presented in Table 15. The petitioner is required to 

submit a revised Section F to reflect appropriate tolerance levels.

Background

The chemical structure and nomenclature of sulfentrazone are presented in Table 1, and the 

physicochemical properties of the technical grade of sulfentrazone are presented in Table 2.
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Table 1. Sulfentrazone Nomenclature.

Chemical structure

Cl

Cl

HN

SO2CH3

N

N

N

O

CH3

CHF2

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)

Chemical structure of DMS 

metabolite

Cl

Cl

HN

SO2CH3

N

N

N

O

CHF2

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

Cl

Cl

HN

SO2CH3

N

N

N

O

CHF2

OH

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
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Table 2. Physicochemical Properties of Technical Grade Sulfentrazone.

Parameter Value Reference

Melting range 120-122 oC

pH 4.78 at 23 oC

Density 0.53 g/cm3

Water solubility 4.0 x 102 μg/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

DP# 288712, 3/6/03, G. 

Kramer, G. Reddy, and L. 

Liu

UV/visible absorption spectrum Not available

860.1200 Directions for Use

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

Table 3. The proposed crop use directions are summarized in Table 4A. Information regarding 

rotational crop restrictions is listed in Table 4B.

Table 3. Summary of Proposed End-Use Products.

Trade Name Reg. No. ai (% of 

formulation)

Formulation 

Type

Target Crops Target Pests Label Date

Spartan®4F 

Herbicide

279-3220 39.6 (4 lb/gal) FlC Specimen label 

code: 

Spartan4F 

_3_12-17-07

Spartan®

Herbicide

279-3189 75 DF

Row Crops: corn 

(field, seed, and pop); 

peanut; potato; 

soybean; sugarcane; 

sunflower; tobacco.

Vegetable Crops: 

asparagus; Brassica, 

head and stem; 

Brassica, leafy greens; 

cabbage (transplant 

only); dry shelled 

beans and peas; 

fruiting vegetables 

(except cucurbits) and 

okra; horseradish; 

melons; strawberry; 

succulent peas and 

beans;

Oil Crops: flax; mint.

Broadleaf, grass, 

and sedge weeds.

Specimen label 

code: Spartan

_3_12-17-07
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Table 4A. Summary of Proposed Directions for Use of Sulfentrazone.

Applic. Timing, 

Type, and Equip.

Formulation

[EPA Reg. No.]

Applic. Rate,

lb ai/A

[Soil Type]

Max. No. Applic. 

per Season

Max. Seasonal 

Applic. Rate

(lb ai/A)

PHI

(days)

Brassica, Head and Stem [broccoli, Chinese broccoli, Brussels sprouts, Chinese (napa) cabbage, Chinese mustard, 

cauliflower, cavalo broccoli, kohlrabi]

4 lb/gal FlC

[279-3220]

75% DF

[279-3189]

0.070-0.281

[coarse]

0.094-0.375

[medium and 

fine]

Not specified

(NS) 0.375 NS

Early preplant, 

preemergence, 

preplant 

incorporated

Use Directions and Limitations Do not incorporate to depths greater than 2 inches.

Brassica, Leafy Greens [broccoli raab, Chinese (bok choy) cabbage, collards, kale, mizuna, mustard greens, 

mustard spinach, rape greens]

4 lb/gal FlC

[279-3220]

75% DF

[279-3189]

0.070-0.281

[coarse]

0.094-0.375

[medium and 

fine]

NS 0.375 NS

Early preplant, 

preemergence, 

preplant 

incorporated

Use Directions and Limitations: Do not incorporate to depths greater than 2 inches.

Fruiting Vegetables (except curcurbits) [eggplant, groundcherry (Physalis spp), pepino, pepper (includes bell 

pepper, chili pepper, cooking pepper, pimento, sweet pepper), tomatillo, tomato] and okra

4 lb/gal FlC

[279-3220]

75% DF

[279-3189]

0.070-0.281

[coarse]

0.094-0.375

[medium and 

fine]

NS 0.375 NS

Preplant banded 

or postemergence 

with 

shielded/hooded 

sprayer

Use Directions and Limitations: None.

Succulent Peas and Beans [bean (Phaseolus; includes green lima bean and succulent broad bean), bean (Vigna; 

includes blackeyed pea, cowpea, southern pea), pea (Pisum; includes English pea, garden pea, green pea); pigeon 

pea 

4 lb/gal FlC

[279-3220]

75% DF

[279-3189]

0.070-0.1875

[coarse]

0.094-0.1875

[medium]

0.117-0.1875

[fine]

NS 0.1875 NS

Preemergence

Use Directions and Limitations: Do not incorporate.

Flax

4 lb/gal FlC

[279-3220]

75% DF

[279-3189]

0.070-0.281

[coarse]

0.094-0.375

[medium and 

fine]

NS 0.375 NS

Preemergence

Use Directions and Limitations: Do not apply directly on crop after the crop emergence or if 

the seedling sprouts are close to the soil surface.
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Melon [citron melon, muskmelon, watermelon]

4 lb/gal FlC

[279-3220]

75% DF

[279-3189]

0.093-0.1875

[coarse]

0.093-0.2125

[medium]

0.117-0.25

[fine]

NS 0.25 NS

Preemergence

Use Directions and Limitations: Do not apply directly on crop after the crop emergence or if 

the seedling sprouts are close to the soil surface.

Strawberry

4 lb/gal FlC

[279-3220]

75% DF

[279-3189]

0.070-0.281

[coarse] 

0.094-0.375

[medium and 

fine]

NS 0.375 NS

Preemergence

Use Directions and Limitations: Do not apply directly on crop after the crop emergence or if 

the seedling sprouts are close to the soil surface.

The following restrictions apply to all proposed crops: Application rates are dependent on soil 

texture, percent organic matter (%OM), and pH. Use on soils classified as sand which have 

<1% OM is prohibited. Applications are to be made in a minimum of 10 gallons per acre (GPA) 

using ground equipment or a minimum of 5 GPA using aerial equipment. 
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Table 4B. 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

Potatoes Anytime

Rice 10

Rye 4

Sorghum 10 2

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.

Conclusions. The use directions are adequate to allow HED an assessment of whether the 

submitted residue data reflect the maximum residues likely to occur. However, the label for 

Spartan®4F Herbicide (EPA Reg. No. 279-3220), a 4 lb/gal FlC (liquid) formulation, should be 

modified to correct the application rates listed as “dry ounces Spartan® Herbicide per acre” to 

“fluid ounces Spartan® Herbicide per acre”. Also, as metabolism data are not available to 

support postemergence applications on fruiting vegetables (except curcurbits), these proposed 

uses should be limited to preemergence application only. Additionally, the proposed labels 

should be revised to specify a maximum single and seasonal application rate of 0.020 lb ai/A to 

Brassica leafy greens, subgroup 5B, as this rate is supported by the submitted crop field trial data 

for mustard greens. A revised Section B is required.

860.1300 Nature of the Residue – Plants and Livestock

DP# 226434, 6/14/96, G. Kramer (HED Metabolism Committee Meeting of 5/20/96)

DP# 220548, 3/13/96, G. Kramer

Data concerning the metabolism of sulfentrazone in soybeans and confined rotational crops were 

submitted in conjunction with the soybean petition (PP#4F04407). Sulfentrazone is metabolized 

via four different pathways: (1) Oxidation of the 3-methyl group to form 3-hydroxymethyl 
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sulfentrazone or HMS, followed by further oxidation to form sulfentrazone carboxylic acid 

which is decarboxylated to 3-desmethyl sulfentrazone or DMS. (2) Hydrolysis of the 

trifluoromethyl group to form desdifluoromethyl sulfentrazone which is oxidized and 

decarboxylated to form desdifluoromethyl desmethyl sulfentrazone. (3) Hydrolysis of the 

sulfonamide group to form desmethylsulfonyl sulfentrazone. (4) Scission of the phenyl and 

triazole rings to produce methyl triazole. The corresponding phenyl metabolites are believed to 

remain bound.

The HED Metabolism Committee has 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 (D226434, 6/14/96, G. 

Kramer). 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 (D220548, 3/13/96, G. 

Kramer). 

For the proposed uses of sulfentrazone, limited to preemergence application, the nature of the 

residue in crops is understood. The residues of concern are sulfentrazone and its metabolites 

HMS and DMS. However, as the enforcement method for plant commodities determines free 

and conjugated forms of the analytes, the tolerance expression should be revised to indicate the 

residues of concern are the combined residues of free and conjugated sulfentrazone, and its 

metabolites HMS and DMS. Additionally, as the proposed directions for use on fruiting 

vegetables include postemergence applications, HED concludes metabolism data are not

available to support the postemergence applications.

Adequate ruminant and poultry metabolism studies were submitted in conjunction with the 

soybean petition (PP#4F04407). The metabolism of sulfentrazone in livestock differs from that 

in plants as metabolism proceeds only by oxidation of the 3-methyl group to form 3-

hydroxymethyl sulfentrazone (HMS), followed by further oxidation to form sulfentrazone 

carboxylic acid which is decarboxylated to 3-desmethyl sulfentrazone (DMS). Sulfentrazone per 

se and its metabolites HMS and DMS were identified as the residues of concern in meat, milk, 

poultry and eggs.

860.1340 Residue Analytical Methods

Letter dated 9/18/98 from G. Kramer to M. Clower (FDA)

D233520, 3/25/97, G. Kramer

Enforcement method

A GC analytical method for the determination of sulfentrazone, DMS, and HMS residues (free 

and conjugated) in/on various matrices was submitted with a petition for a sulfentrazone 

tolerance on soybeans (PP# 4F04407). A PMV was successfully completed by the Agency’s 

ACL. The LOQ and LOD were determined to be 0.05 ppm and 0.005-0.025 ppm, respectively. 

HED concluded that the method is suitable for enforcement purposes (D233520, G. Kramer, 

3/25/97). The method was forwarded to FDA for inclusion in PAM II (Letter, G. Kramer, 

9/18/98). This method is suitable for enforcement of the tolerances associated with this petition.
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

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Data-collection methods

Samples of raw agricultural commodities (RACS) and processed commodities were analyzed for 

residues of sulfentrazone and its metabolites DMS and HMS using the FMC method entitled, 

“Analytical Methodology for the Determination of Sulfentrazone, 3-Desmethyl Sulfentrazone, 

and 3-Hydroxymethyl Sulfentrazone in/on Various Matrices, Study Number 162MVL96R1” with 

minor modifications. Residues in/on broccoli and mustard greens were determined using 

GC/XSD, while residues in/on cantaloupe, fruiting vegetables (pepper and tomato), peas, flax, 

and strawberry were determined using LC/MS/MS.

Briefly, homogenized samples were refluxed with acetone:0.25N HCl (30:10, v:v) for 1 hour 

followed by filtration and concentration, then refluxed a second time with 1N HCI for 2 hours to 

free all conjugated analytes of concern and to completely convert sulfentrazone 3-carboxylic acid 

(SCA) to DMS. The method quantifies residues of SCA as DMS and calculates SCA residues by

a molecular weight-conversion factor (1.12). SCA is a metabolism intermediate in formation of 

DMS. The extract was filtered, cleaned-up on a C8 solid-phase extraction (SPE) cartridge and 

eluted with acetonitrile. The eluate was dried under a gentle stream of nitrogen and additionally 

cleaned up on a silicon (Si) SPE; eluted twice with ethyl acetate:hexane (60:40, v:v). The eluates 

were combined, concentrated, and reconstituted with acetonitrile. For samples of broccoli and 

mustard greens, an aliquot was analyzed for sulfentrazone and DMS by GC/XSD. A second 

aliquot was derivatized with BSTFA (N,O-bis[trimenthylsilyl]trifluoroacetamide) and analyzed 

for HMS by GC/XSD. For samples of cantaloupe, fruiting vegetables (pepper and tomato), peas, 

flax, and strawberry and the processed commodities of flax and tomato, the eluate was 

concentrated to near dryness and brought to volume with 25% acetonitrile in water for analysis 

by LC/MS/MS. For tomato samples, the SPE cleanup steps were eliminated; after filtration, the 

aqueous solution was brought to volume with water and analyzed by LC/MS/MS.

The data-collection methods described above are adequate based on acceptable method 

validation and concurrent recovery data.

860.1360 Multiresidue Methods

Residue Chemistry Memo, 2/7/95, G. Kramer

MRM data for sulfentrazone and HMS were previously submitted and forwarded to FDA 

(Memo, 2/7/95, G. Kramer). Neither compound was recovered by any of the protocols. The 

FDA PESTDATA database dated 10/99 (PAM Vol. I, Appendix II) indicates that DMS is not 

recovered using MRM Sections 303 (Mills, Onley, and Gaither; Protocol E, nonfatty) and 304 

(Mills, fatty food). No information for recovery of DMS using Section 302 (Luke Method; 

Protocol D) is available.

860.1380 Storage Stability

IR-4 conducted concurrent storage stability studies with the broccoli, cantaloupe, flax, mustard 

greens, pea (succulent shelled and edible-podded), pepper, strawberry, and tomato field trials, 

and the flax and tomato processing studies. 
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

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The results indicate that residues of sulfentrazone, DMS, and HMS are reasonably stable under 

frozen storage conditions in/on broccoli for 427 days, cantaloupe for 352 days, flax seed for 484 

days, mustard greens for 391 days, pea (succulent shelled and edible-podded) for 757 days, 

pepper for 596 days, strawberry for 389 days, tomato and tomato paste for 552 days, flax meal 

for 500 days, and flax oil for 494 days. The storage durations and conditions of samples from the 

crop field trials submitted to support this petition are presented in Table 5.

Table 5. Summary of Storage Conditions and Durations of Samples from

Crop Field Trial and Processing Studies.

Matrix Storage 

Temperature (°C)

Actual Storage 

Duration

Interval of Demonstrated Storage Stability

Broccoli -38 to -3 Treated samples:

234-403 days

(7.7-13.3 months)

Control samples:

236-446 days

(7.7-14.7 months)

Residues of sulfentrazone, DMS, and HMS are 

stable in frozen storage in/on broccoli for up to 427 

days.

Mustard greens -38 to -3 Treated samples: 

104-351 days

(3.4-11.5 months)

Control samples: 

99-439 days

(3.3-14.4 months)

Residues of sulfentrazone, DMS, and HMS are 

stable in/on mustard greens during frozen storage 

for up to 391 days.

Pea, succulent -38 to -1 385-742 days

(12.7-24.4 months)

Residues of sulfentrazone, DMS, and HMS are 

stable in/on peas stored frozen for up to 757 days.

Pepper -40 to -2 Treated: 450-584 

days

(14.8-19.2 months)

Control: 450-610 

days

(14.8-20.0 months)

Residues of sulfentrazone, DMS, and HMS are 

stable in frozen storage in/on peppers for up to 596 

days.

Tomato ~ -18 483-573 days

(15.9-18.8 months)

Residues of sulfentrazone, DMS, and HMS are 

stable in frozen storage in/on tomatoes for up to 

552 days.

Tomato RAC 506 days

(16.6 months)

Tomato puree 513-519 days 

(16.9-17.1 months)

Tomato paste

-12 (processing 

facility)

-18 (analytical 

laboratory)

500-506 days 

(16.4-16.6 months)

Residues of sulfentrazone, DMS, and HMS are 

stable in frozen storage in/on tomatoes and tomato 

paste for up to 552 days.

Cantaloupe -38 to -6 278-364 days

(9.1-12.0 months)

Residues of sulfentrazone, DMS, and HMS are 

stable in frozen storage in/on cantaloupe for up to 

352 days.

Strawberry -38 to -1 Treated samples: 

116-394 days

(3.8-13.0 months)

Control samples: 

116-434 days 

(3.8-14.3 months)

Residues of sulfentrazone, DMS, and HMS are 

stable in frozen storage in/on strawberries for up to 

389 days.
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

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Flax, seed -38 to 0.7 354-382 days

(11.6-12.6 months)

Residues of sulfentrazone, DMS, and HMS are 

stable in/on flax seed during frozen storage for up 

to 484 days.

Flax, seed Treated: 407 days

(13.4 months)

Control: 406-410 

days

(13.4-13.5 months)

Flax, meal Treated: 468 days

(15.4 months)

Control: 460-623 

days

(15.1-20.5 months)

Flax, oil

-29 to -14

(processing facility)

-38 to 0.7

(analytical laboratory)

Treated: 443 days

(14.6 months)

Control: 434-624 

days

(14.3-20.5 months)

Residues of sulfentrazone, DMS, and HMS are 

stable in frozen storage for up to 484 days in/on 

flax seed, 500 days in/on flax meal, and 494 days 

in/on flax oil.

Conclusions. The available storage stability data for sulfentrazone are adequate to support the 

storage conditions and durations of samples of broccoli, cantaloupe, flax, mustard greens, pea 

(succulent shelled and edible-podded), pepper, strawberry, and tomato from the submitted crop 

field trials and the flax and tomato processing studies. There are no storage stability issues and 

no corrections for storage stability need be applied to the field trial and processing studies.

860.1480 Meat, Milk, Poultry, and Eggs

PP#s 2F6391, 2E6498, 2E6405, & 2E6500; D287102, 1/10/03, G. Kramer

HED previously determined that, based on the established sulfentrazone tolerances for soybean 

and cereal grain commodities and the results of the livestock metabolism studies, conventional 

feeding studies are not required. This conclusion was reevaluated in conjunction with PP#s 

2F6391 and 2E6405 (D287102, 1/10/03, G. Kramer) based on revised dietary burdens resulting 

from a diet comprised of corn and potato commodities for beef and dairy cattle and corn and rice 

commodities for poultry. Since a dietary exposure of 10x would not result in quantifiable 

residues, HED concluded that conventional ruminant and poultry feeding studies were still not 

required.

In the current petition, the only livestock feedstuff is flax meal. Flax meal is a feed commodity

for cattle and swine (10% of diet) and poultry (30% of diet), but would contribute a minor 

percentage to livestock diets compared to soybeans and cereal grains. Residues of sulfentrazone 

and its metabolites in/on flax will not result in a higher dietary burden, and tolerances for 

residues in/on meat, milk, poultry, and egg are not required to support preemergence uses on 

flax.
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

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860.1500 Crop Field Trials

Vegetable, tuberous and corm, subgroup 1C

PP#s 2F6391, 2E6498, 2E6405, & 2E6500; D287102, 1/10/03, G. Kramer

No new tuberous and corm vegetable 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 potato at 0.15 ppm [40 CFR §180.498(a)(2)]. Since potato is the representative commodity

for the tuberous and corm vegetable, subgroup 1C, IR-4 is proposing to convert the individual 

tolerance for potato to a crop subgroup 1C tolerance at the same level.

The available potato field trial data (MRID 45582201) were reviewed in conjunction with 

PP#2E6405. Fourteen potato field trials were conducted in WA (3 trials), ID (2 trials), ME, FL, 

NC, OH, CO, ND, NJ, NY, and CA at seasonal application rates of 0.375 lb ai/A (1x the 

maximum proposed seasonal rate) with PHIs of 68-158 days. The maximum combined residues 

of sulfentrazone and its metabolites HMS and DMS were 0.077 ppm in/on treated potato tubers.

Conclusions. The previously submitted residue data for potato are adequate to support the 

proposed crop subgroup tolerance of 0.15 ppm for tuberous and corm vegetables, subgroup 1C.

Brassica, head and stem, subgroup 5A

Broccoli

47311401.der.doc

IR-4 has submitted field trial data for sulfentrazone on broccoli, a representative commodity of 

the Brassica head and stem subgroup 5A. Six field trials were conducted on broccoli in the 

United States in Zones 1 (NY; 1 trial), 6 (TX; 1 trial), 10 (CA and NM; 3 trials), and 12 (OR; 1 

trial) during the 2001 growing season. Each trial site consisted of one untreated plot and one 

treated plot. A 4 lb/gal FlC formulation of sulfentrazone was applied as a single broadcast 

application to soil 72 hours prior to transplanting broccoli or to direct seeded broccoli at the 2-4 

leaf growth stage, at a rate of 0.34-0.38 lb ai/A (~0.9-1.0x the maximum proposed seasonal rate). 

The applications were made in 19-35 GPA spray volumes, without an adjuvant. Mature broccoli 

was harvested at 45 to 73-day PHIs.

Residues of sulfentrazone, DMS, and HMS were each below the LOQ (<0.05 ppm) in/on all 

samples of broccoli harvested 45-73 days following one broadcast application either to soil 72 

hours prior to transplanting or to direct seeded broccoli at the 2- to 4-leaf growth stage at a rate of 

0.34-0.38 lb ai/A; see Table 6. Total sulfentrazone residues were all <0.15 ppm in/on all treated 

samples of broccoli.
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

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Table 6. Summary of Residue Data from Broccoli Field Trials with Sulfentrazone.

Commodity Total Applic. Residue Levels(ppm)

Rate

(lb ai/A)

PHI 

(days) n Min. Max. HAFT1 Median Mean Std. Dev.

Proposed Use Pattern: Preplant/preemergence application at a maximum rate of 0.375 lb ai/A

Sulfentrazone

Broccoli 0.34-0.38 45-73 12 <0.05 <0.05 <0.05 <0.05 <0.05 --

DMS

Broccoli 0.34-0.38 45-73 12 <0.05 <0.05 <0.05 <0.05 <0.05 --

HMS

Broccoli 0.34-0.38 45-73 12 <0.05 <0.05 <0.05 <0.05 <0.05 --

Total

Broccoli 0.34-0.38 45-73 12 <0.15 <0.15 <0.15 <0.15 <0.15 --

1 HAFT = highest-average field trial. For calculation of the total residues, HAFT, median, and mean, the LOQ value (<0.05 

ppm) was used for all residues reported as below the LOQ.

Varying degrees of phytotoxicity were reported at both CA trial sites and at the NY and TX trial

sites. The petitioner indicated that treated broccoli plants were stunted with burned, curled 

leaves. Although phytotoxicity was attributed to the test substance application, these isolated 

instances of phytotoxicity did not have an adverse impact on the residue trials.

Cabbage

PP#1E6311, DP# 276111, 12/9/02, G. Kramer

A tolerance of 0.20 ppm has been established [40 CFR §180.498(a)(2)] for the combined 

residues of sulfentrazone and its metabolites HMS and DMS in/on cabbage based on residue data 

reviewed in PP#1E6311. These data indicate that the combined residues of sulfentrazone, HMS, 

and SCA (quantified as DMS) were <0.15-0.18 ppm and <0.15-0.17 ppm in/on cabbage heads 

with and without wrapper leaves, respectively, harvested 68-104 days following a single ground 

broadcast application of the 75% DF formulation at 0.375 lb ai/A (1x rate) made 1-3 days prior 

to transplanting or at the 2- to 4-leaf growth stage (33 days after planting) to direct seeded 

cabbage. The petition review concluded that two additional cabbage field trials should be 

conducted in Regions 1 and 8 as a condition for full registration.

Conclusions: The submitted residue data for broccoli along with the previously reviewed data 

for cabbage are adequate to support the proposed crop subgroup tolerance of 0.20 ppm for 

Brassica head and stem, subgroup 5A. Following application of a representative formulation of 

sulfentrazone at 1x, the combined residues of sulfentrazone, DMS, and HMS were <0.15 ppm 

in/on broccoli, <0.15-0.18 ppm in/on cabbage heads with wrapper leaves, and <0.15-0.17 ppm 

in/on cabbage heads without wrapper leaves. As a condition for full registration, HED 

previously required two additional cabbage field trials to be conducted in Regions 1 and 8.

These trials are no longer needed since an adequate number of broccoli and cabbage field trials 

are available to satisfy geographic representation for head and stem Brassica, subgroup 5A. 

Brassica, leafy greens, subgroup 5B

Mustard Greens

47311402.der.doc
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

Page 18 of 34

IR-4 has submitted field trial data for sulfentrazone on mustard greens, the representative 

commodity of the Brassica leafy greens subgroup 5B. Seven field trials were conducted on 

mustard greens in the United States in Zones 2 (GA and NJ; 2 trials), 3 (FL; 1 trial), 4 (TN; 1 

trial), 5 (OH; 1 trial), 6 (TX; 1 trial), and 10 (CA; 1 trial) during the 2001-2002 growing seasons. 

Each trial consisted of one untreated plot and two treated plots, except for one trial (TN) which 

contained three treated plots. Each treated plot received a single preemergence broadcast soil 

application of a 4 lb/gal FlC formulation of sulfentrazone at target rates of ~0.10 lb ai/A (~0.3x; 

Treatment Plot 2), ~0.20 lb ai/A (~0.5x; Treatment Plot 3) or ~0.40 lb ai/A (~1.1x; Treatment 

Plot 4). All applications were made in 20-40 GPA spray volumes, without an adjuvant. Mature 

samples were collected 40-66 days after treatment.

The results of the field trials indicate that residues of sulfentrazone were all below the LOQ 

(<0.05 ppm) in/on all samples of mustard greens harvested 40-66 days following a preemergence 

broadcast soil application of a 4 lb/gal FlC formulation of sulfentrazone at a rate of ~0.10 lb ai/A 

(Treatment Plot 2), ~0.20 lb ai/A (Treatment Plot 3) or ~0.40 lb ai/A (Treatment Plot 4); see 

Table 7. Maximum residues of DMS were 0.098 ppm, 0.136 ppm, and <0.05 ppm in/on mustard 

green samples from Treatment Plots 2, 3, and 4, respectively. Maximum residues of HMS were 

0.051 ppm, 0.162 ppm, and <0.05 ppm in/on mustard green samples from Treatment Plots 2, 3, 

and 4, respectively. Maximum total residues were 0.198 ppm, 0.291 ppm, and <0.15 ppm in/on 

mustard green samples from Treatment Plots 2, 3, and 4, respectively.

Table 7. Summary of Residue Data from Mustard Green Field Trials with Sulfentrazone.

Commodity PHI Residue Levels(ppm)

(days)

Trt 

Plot

No.

Total

Applic.

Rate

(lb ai/A)

n Min. Max. HAFT1 Median Mean Std. Dev.

Proposed Use Pattern: Preplant/preemergence application at a maximum rate of 0.375 lb ai/A

Sulfentrazone

2 0.092-0.108 14 <0.05 <0.05 <0.05 <0.05 <0.05 --

3 0.199-0.222 14 <0.05 <0.05 <0.05 <0.05 <0.05 --

Mustard greens, 

leaves

40-66

4 0.402 2 <0.05 <0.05 <0.05 <0.05 <0.05 --

DMS

2 0.092-0.108 14 <0.05 0.098 0.074 <0.05 0.053 0.013

3 0.199-0.222 14 <0.05 0.136 0.109 <0.05 0.058 0.024

Mustard greens, 

leaves

40-66

4 0.402 2 <0.05 <0.05 <0.05 <0.05 <0.05 --

HMS

2 0.092-0.108 14 <0.05 0.051 0.051 <0.05 <0.050 0.000

3 0.199-0.222 14 <0.05 0.162 0.148 <0.05 0.070 0.037

Mustard greens, 

leaves

40-66

4 0.402 2 <0.05 <0.05 0.05 <0.05 <0.05 --

Total

2 0.092-0.108 14 <0.15 <0.198 0.174 <0.15 0.154 0.013

3 0.199-0.222 14 <0.15 <0.291 0.248 <0.15 0.178 0.049

Mustard greens, 

leaves

40-66

4 0.402 2 <0.15 <0.15 <0.15 <0.15 <0.15 --

1 HAFT = highest-average field trial. For calculation of the total residues, HAFT, median, and mean, the LOQ value (<0.05 

ppm) was used for all residues reported as below the LOQ.

Varying degrees of phytotoxicity were reported at the FL and GA trial sites. The petitioner noted 

that crops were stunted by 15% (Treatment Plot 2) and 75% (Treatment Plot 3) at the GA trial

site and 20% (Treatment Plot 2) and 45% (Treatment Plot 3) at the FL site. Although 
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

Page 19 of 34

phytotoxicity was attributed to the test substance application, these isolated instances of 

phytotoxicity did not have an adverse impact on the residue trials.

Conclusions: The submitted residue data for mustard greens, which is the representative 

commodity of Brassica leafy greens, subgroup 5B, are adequate to fulfill data requirements

provided the use directions are revised to indicate a maximum single and seasonal application 

rate of 0.20 lb ai/A. The number and locations of crop field trials are in accordance with OPPTS 

Guideline 860.1500 and the trials conducted reflect the revised proposed use pattern. The 

residue data for mustard greens indicate that total residues were <0.15 ppm in/on two samples 

treated at 0.402 lb ai/A (~1.1x). It is noted that higher residues were observed on samples treated 

at <1.0x. Maximum total residues of <0.198 ppm and <0.291 ppm were reported in/on samples 

treated at ~0.3x and ~0.5x. The residue data for mustard greens were not entered into the 

Agency’s tolerance spreadsheet as specified by the Guidance for Setting Pesticide Tolerances 

Based on Field Trial Data SOP to determine the tolerance level as more than half of the samples 

(8 of 14) had residues that were less then the LOQ (0.05 ppm). HED concludes a tolerance level 

of 0.40 ppm for free and conjugated residues of sulfentrazone, HMS and DMS in/on Brassica

leafy greens, subgroup 5B. A revised Section F is required.

Vegetable, Legume, Group 6

Pea, succulent

47311406.der.doc

IR-4 has submitted field trial data for sulfentrazone on succulent shelled and edible-podded peas. 

Eleven pea field trials were conducted in the United States during the 2003-2004 growing 

seasons. Eight field trials were conducted on succulent shelled peas in Zones 1 (NY; 1 trial), 5 

(MI, OH, and WI; 4 trials), 11 (ID and WA; 2 trials), and 12 (OR; 1 trial). Three edible-podded 

pea trials were conducted in Zones 2 (NJ; 1 trial) and 10 (CA; 2 trials). Each trial consisted of 

one untreated plot and two treated plots. Each treated plot received a single preemergence 

broadcast soil application of a 75% DF formulation of sulfentrazone at a rate of ~0.1875 lb ai/A 

(1x; Treatment Plot 2), or ~0.25 lb ai/A (1.3x; Treatment Plot 3). All applications were made in 

20-38 GPA spray volumes, without an adjuvant. Mature peas were collected from treatment 

plots at 52- to 168-day PHIs.

The results of the field trials show that residues of sulfentrazone, DMS, and HMS were each 

below the LOQ (<0.05 ppm) in/on samples of peas (succulent shelled and edible-podded) 

harvested 52-168 days after a single preemergence broadcast application of a 75% DF 

formulation of sulfentrazone made to soil at target rates of ~0.1875 lb ai/A (1x; Treatment Plot 2) 

or ~0.25 lb ai/A (1.3x; Treatment Plot 3); see Table 8. Total sulfentrazone residues were <0.15 

ppm in/on all treated samples of succulent shelled and edible-podded peas.
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Table 8. Summary of Residue Data from Succulent Pea Field Trials with Sulfentrazone.

Commodity PHI Residue Levels (ppm)

(days)

Trt

No.

Total

Applic.

Rate

(lb ai/A)

n Min. Max. HAFT Median Mean Std. Dev.

Proposed Use Pattern: Preemergence application at a maximum rate of 0.1875 lb ai/A

Sulfentrazone

Pea, succulent 2 0.181-0.198 22 <0.05 <0.05 <0.05 <0.05 <0.05 --

shelled and 

edible-podded

52-168

3 0.242-0.264 22 <0.05 <0.05 <0.05 <0.05 <0.05 --

DMS

Pea, succulent 2 0.181-0.198 22 <0.05 <0.05 <0.05 <0.05 <0.05 --

shelled and 

edible-podded

52-168

3 0.242-0.264 22 <0.05 <0.05 <0.05 <0.05 <0.05 --

HMS

Pea, succulent 2 0.181-0.198 22 <0.05 <0.05 <0.05 <0.05 <0.05 --

shelled and 

edible-podded

52-168

3 0.242-0.264 22 <0.05 <0.05 <0.05 <0.05 <0.05 --

Total

Pea, succulent 2 0.181-0.198 22 <0.15 <0.15 <0.15 <0.15 <0.15 --

shelled and 

edible-podded

52-168

3 0.242-0.264 22 <0.15 <0.15 <0.15 <0.15 <0.15 --

1 HAFT = highest-average field trial. For calculation of the total residues, HAFT, median, and mean, the LOQ value (<0.05 

ppm) was used for all residues reported as below the LOQ.

Varying degrees of phytotoxicity were reported at five of the trial sites. The petitioner reported 

the following phytotoxic effects: (i) at the NY and OH trials, stunting with slight yellowing 

which increased with treatment rate, (ii) at the NJ site, whitening and yellowing of foliage in 20% 

of plants, (iii) at one CA site crop stunting with lower leaf burning of 50-75% of crops. No 

phytotoxic effects were noted at the six remaining trials. Although phytotoxicity was attributed 

to the test substance application, these isolated instances of phytotoxicity did not have an adverse 

impact on the residue trials.

Conclusions: The submitted residue data for succulent peas are adequate to fulfill data 

requirements. The number and locations of crop field trials are in accordance with OPPTS 

Guideline 860.1500, and the trials conducted reflect the proposed use pattern. The field trial data 

will support a tolerance of 0.15 ppm for succulent peas. The combined residues of sulfentrazone, 

DMS, and HMS were <0.15 ppm in/on mature peas (succulent shelled and edible-podded) 

following treatment according to the proposed use pattern. A revised Section F is required since 

the petitioner has proposed a tolerance level of 0.05 ppm for residues in/on mature peas 

(succulent shelled and edible-podded).

Vegetable, fruiting, group 8

47311404.der.doc (includes MRID 47311405)

IR-4 has submitted field trial data for sulfentrazone on peppers (bell and non-bell) and tomatoes, 

the representative commodities of the fruiting vegetables, crop group 8. Twenty-four fruiting 

vegetable field trials were conducted in the United States during the 2004 growing season. Six 

bell pepper trials were conducted in Zones 2 (MD; 1 trial), 3 (FL; 1 trial), 5 (WI; 1 trial), 6 (TX; 

1 trial), and 10 (CA; 2 trials). Four non-bell pepper trials were conducted in Zones 2 (GA; 1 
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

Page 21 of 34

trial), 5 (WI; 1 trial), 6 (TX; 1 trial), and 10 (NM; 1 trial). Fourteen tomato trials were conducted 

in Zones 1 (NY; 1 trial), 2 (MD and NC; 2 trials), 3 (FL; 2 trials), 5 (MI; 1 trial), and 10 (CA and

NM; 8 trials).

Each trial consisted of one untreated plot and multiple (at least two) treatment plots. Each 

treatment plot received one banded application to the soil surface made at pre-transplant stage 

followed by one postemergence application between rows using a shielded/hooded sprayer. 

Treatment Plots 2, 3, and 4 were treated with a 4 lb/gal FlC formulation whereas Treatment Plots 

5 and 6 were treated with a 75% DF formulation of sulfentrazone. Treatment Plots 2 and 5 

received two applications at ~0.250 lb ai/A for a total rate of ~0.500 lb ai/A (1.3x). Treatment 

Plots 3 and 6 received two applications at ~0.375 lb ai/A for a total rate of ~0.750 lb ai/A (2.0x). 

Treatment Plot 4 received two applications at ~0.200 lb ai/A for a total rate of ~0.400 lb ai/A 

(1.1x). Peppers were treated at a 47- to 84-day RTI, and tomatoes were treated at a 34- to 99-day

RTI. The second application made to each tomato treated plot at the MD site was over-applied 

by ~64%. Mature peppers and tomatoes were collected at 19- to 22-day PHIs.

The crop field study shows that residues of sulfentrazone, DMS, and HMS were each <LOQ 

(<0.05 ppm) in/on all samples of peppers and tomatoes harvested 19-22 days following the last 

of two applications (a soil surface, pre-transplant, banded application followed by a

postemergence application made between rows with a shielded/hooded sprayer) of either a 4 

lb/gal FlC formulation or a 75% DF formulation of sulfentrazone, at total rates of 0.40 lb ai/A

(1.1x), 0.50 lb ai/A (1.3x), and 0.75 lb ai/A (2.0x); see Table 9. Total combined residues of 

sulfentrazone, DMS, and HMS were all <0.15 ppm in/on all treated samples of peppers and 

tomatoes. No residue decline data were submitted; however, decline data are not required 

because residues were nonquantifiable at the earliest harvest time.

Table 9. Summary of Residue Data from Fruiting Vegetable Field Trials with Sulfentrazone.

Commodity PHI Residue Levels(ppm)

(days)

Trt 

Plot

No.

Total

Applic.

Rate

(lb ai/A)

n Min. Max. HAFT

1 Median Mean Std. Dev.

Proposed Use Pattern: Preplant or postemergence application at a maximum seasonal rate of 0.375 lb ai/A

Sulfentrazone

19-21 2 0.505-0.512 12 <0.05 <0.05 <0.05 <0.05 <0.05 --

3 0.739-0.773 12 <0.05 <0.05 <0.05 <0.05 <0.05 --

4 0.410 2 <0.05 <0.05 <0.05 <0.05 <0.05 --

5 0.504-0.507 4 <0.05 <0.05 <0.05 <0.05 <0.05 --

Bell Pepper

21

6 0.758-0.779 4 <0.05 <0.05 <0.05 <0.05 <0.05 --

Non-bell pepper 19-22 2 0.499-0.505 8 <0.05 <0.05 <0.05 <0.05 <0.05 --

3 0.750-0.761 8 <0.05 <0.05 <0.05 <0.05 <0.05 --

19-21 2 0.489-1.004 28 <0.05 <0.05 <0.05 <0.05 <0.05 --

3 0.730-0.982 28 <0.05 <0.05 <0.05 <0.05 <0.05 --

21 4 0.537 2 <0.05 <0.05 <0.05 <0.05 <0.05 --

5 0.490-0.504 4 <0.05 <0.05 <0.05 <0.05 <0.05 --

Tomato

19-21

6 0.739-0.758 4 <0.05 <0.05 <0.05 <0.05 <0.05 --
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

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DMS

19-21 2 0.505-0.512 12 <0.05 <0.05 <0.05 <0.05 <0.05 --

3 0.739-0.773 12 <0.05 <0.05 <0.05 <0.05 <0.05 --

4 0.410 2 <0.05 <0.05 <0.05 <0.05 <0.05 --

5 0.504-0.507 4 <0.05 <0.05 <0.05 <0.05 <0.05 --

Bell Pepper

21

6 0.758-0.779 4 <0.05 <0.05 <0.05 <0.05 <0.05 --

Non-bell pepper 19-22 2 0.499-0.505 8 <0.05 <0.05 <0.05 <0.05 <0.05 --

3 0.750-0.761 8 <0.05 <0.05 <0.05 <0.05 <0.05 --

19-21 2 0.489-1.004 28 <0.05 <0.05 <0.05 <0.05 <0.05 --

3 0.730-0.982 28 <0.05 <0.05 <0.05 <0.05 <0.05 --

21 4 0.537 2 <0.05 <0.05 <0.05 <0.05 <0.05 --

5 0.490-0.504 4 <0.05 <0.05 <0.05 <0.05 <0.05 --

Tomato

19-21

6 0.739-0.758 4 <0.05 <0.05 <0.05 <0.05 <0.05 --

HMS

19-21 2 0.505-0.512 12 <0.05 <0.05 <0.05 <0.05 <0.05 --

3 0.739-0.773 12 <0.05 <0.05 <0.05 <0.05 <0.05 --

4 0.410 2 <0.05 <0.05 <0.05 <0.05 <0.05 --

5 0.504-0.507 4 <0.05 <0.05 <0.05 <0.05 <0.05 --

Bell Pepper

21

6 0.758-0.779 4 <0.05 <0.05 <0.05 <0.05 <0.05 --

Non-bell pepper 19-22 2 0.499-0.505 8 <0.05 <0.05 <0.05 <0.05 <0.05 --

3 0.750-0.761 8 <0.05 <0.05 <0.05 <0.05 <0.05 --

19-21 2 0.489-1.004 28 <0.05 <0.05 <0.05 <0.05 <0.05 --

3 0.730-0.982 28 <0.05 <0.05 <0.05 <0.05 <0.05 --

21 4 0.537 2 <0.05 <0.05 <0.05 <0.05 <0.05 --

5 0.490-0.504 4 <0.05 <0.05 <0.05 <0.05 <0.05 --

Tomato

19-21

6 0.739-0.758 4 <0.05 <0.05 <0.05 <0.05 <0.05 --

Total

19-21 2 0.505-0.512 12 <0.15 <0.15 <0.15 <0.15 <0.15 --

3 0.739-0.773 12 <0.15 <0.15 <0.15 <0.15 <0.15 --

4 0.410 2 <0.15 <0.15 <0.15 <0.15 <0.15 --

5 0.504-0.507 4 <0.15 <0.15 <0.15 <0.15 <0.15 --

Bell Pepper

21

6 0.758-0.779 4 <0.15 <0.15 <0.15 <0.15 <0.15 --

Non-bell pepper 19-22 2 0.499-0.505 8 <0.15 <0.15 <0.15 <0.15 <0.15 --

3 0.750-0.761 8 <0.15 <0.15 <0.15 <0.15 <0.15 --

19-21 2 0.489-1.004 28 <0.15 <0.15 <0.15 <0.15 <0.15 --

3 0.730-0.982 28 <0.15 <0.15 <0.15 <0.15 <0.15 --

21 4 0.537 2 <0.15 <0.15 <0.15 <0.15 <0.15 --

5 0.490-0.504 4 <0.15 <0.15 <0.15 <0.15 <0.15 --

Tomato

19-21

6 0.739-0.758 4 <0.15 <0.15 <0.15 <0.15 <0.15 --

1 HAFT = highest-average field trial. For calculation of the total residues, HAFT, median, and mean, the LOQ value (<0.05 

ppm) was used for all residues reported as below the LOQ.

Conclusions: The submitted residue data for peppers (bell and non-bell) and tomatoes are 

adequate. The number and locations of crop field trials are in accordance with OPPTS Guideline 

860.1500 and the trials conducted reflect the proposed use pattern. The field trial data will 

support a tolerance of 0.15 ppm for residues in/on fruiting vegetables, crop group 8. Following 

two applications (a soil surface, pre-transplant, banded application followed by a postemergence

application made between rows with a shielded/hooded sprayer) of representative formulations at 

~1.1-2.0x, the combined residues of sulfentrazone, DMS, and HMS were <0.15 ppm in/on the 
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

Page 23 of 34

representative commodities. A revised Section B is required to remove postemergence uses on 

the labels since metabolism data are not available to support this use pattern. A revised Section F 

is also required since the petitioner has proposed a crop group tolerance level of 0.05 ppm.

Okra

Okra residue data were not submitted in support the proposed use on okra. IR-4 has proposed to 

translate the existing and submitted fruiting vegetable data (peppers and tomatoes) to okra. The 

proposed use on okra is identical to the proposed use on the fruiting vegetables crop group. HED 

has approved adding okra to the fruiting vegetable crop group (see minutes of ChemSAC 

meeting of 10/18/06). Until 40 CFR §180.41 is updated, a separate tolerance must be established 

for residues in/on okra.

Conclusions. The available data for the fruiting vegetables, crop group 8 may used to support the 

proposed tolerance for residues in/on okra. The tolerance should be established at the same level 

as the fruiting vegetable group tolerance, 0.15 ppm.

Melon subgroup 9A

47311403.der.doc

IR-4 has submitted field trial data for sulfentrazone on cantaloupe, the representative commodity

of the melon subgroup 9A. Eight field trials were conducted on cantaloupe in the United States 

in Zones 1 (NY; 1 trial), 2 (NC; 1 trial), 5 (WI; 1 trial), 6 (TX; 1 trial), 9 (CO; 1 trial), and 10 

(CA and NM; 3 trials) during the 2002 growing season. Each trial consisted of one untreated 

plot and two treated plots, except for one trial (NY) which had three treated plots. Each treated 

plot received a single broadcast application of a 75% DF formulation of sulfentrazone to soil 

surface at pre-transplant or preemergence at rates of ~0.20 lb ai/A (0.8x; Treatment Plot 2), ~0.25 

lb ai/A (1.0x; Treatment Plot 3) or ~0.15 lb ai/A (0.6x; Treatment Plot 4). Applications were 

made in 21-42 GPA, without an adjuvant. Mature cantaloupes were collected from the fields at 

59- to 94-day PHIs.

The results of the field trials indicate that residues of sulfentrazone, DMS, and HMS were below 

the LOQ (<0.05 ppm) in/on all samples of cantaloupe harvested 59-94 days after a single

broadcast application of a 75% DF formulation of sulfentrazone to soil surface at pre-transplant 

or preemergence at rates of ~0.20 lb ai/A (Treatment Plot 2), ~0.25 lb ai/A (Treatment Plot 3) or 

~0.15 lb ai/A (Treatment Plot 4), with one exception; see Table 10. In one CA trial, residues of 

HMS were 0.052 ppm in/on cantaloupe samples from Treatment Plot 2. Maximum total residues 

were <0.152 ppm, <0.15 ppm, and <0.15 ppm in/on cantaloupes from Treatment Plots 2, 3, and 

4, respectively.
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

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Table 10. Summary of Residue Data from Cantaloupe Field Trials with Sulfentrazone.

Commodity PHI Residue Levels (ppm)

(days)

Trt

No.

Total

Applic.

Rate

(lb ai/A)

n Min. Max. HAFT1 Median Mean Std. Dev.

Proposed Use Pattern: Preemergence application at a maximum seasonal rate of 0.25 lb ai/A

Sulfentrazone

2 0.20-0.22 16 <0.05 <0.05 <0.05 <0.05 <0.05 --

3 0.25-0.27 16 <0.05 <0.05 <0.05 <0.05 <0.05 --

Cantaloupe, 

fruit

59-94

4 0.16 2 <0.05 <0.05 <0.05 <0.05 <0.05 --

DMS

2 0.20-0.22 16 <0.05 <0.05 <0.05 <0.05 <0.05 --

3 0.25-0.27 16 <0.05 <0.05 <0.05 <0.05 <0.05 --

Cantaloupe, 

fruit

59-94

4 0.16 2 <0.05 <0.05 <0.05 <0.05 <0.05 --

HMS

2 0.20-0.22 16 <0.05 0.052 0.051 <0.05 <0.05 --

3 0.25-0.27 16 <0.05 <0.05 <0.05 <0.05 <0.05 --

Cantaloupe, 

fruit

59-94

4 0.16 2 <0.05 <0.05 <0.05 <0.05 <0.05 --

Total

2 0.20-0.22 16 <0.15 <0.152 <0.151 <0.15 <0.15 --

3 0.25-0.27 16 <0.15 <0.15 <0.15 <0.15 <0.15 --

Cantaloupe, 

fruit

59-94

4 0.16 2 <0.15 <0.15 <0.15 <0.15 <0.15 --

1 HAFT = highest-average field trial. For calculation of the total residues, HAFT, median, and mean, the LOQ value (<0.05 

ppm) was used for all residues reported as below the LOQ.

Varying degrees of phytotoxicity were reported at four trial sites (CA; 2 trials, NC, and NY). 

The petitioner noted that leaf crinkling, necrosis, and stunted growth were observed in crops at 

the NY site, crops from the NC site had marginal and intervenal necrosis, and crops from two 

CA trials were reported to have stunted growth, leaf discoloration, burning, and distortion. 

Although phytotoxicity was attributed to the test substance application, these isolated instances 

of phytotoxicity did not have an adverse impact on the residue trials.

Conclusions: The submitted residue data for cantaloupes are adequate to support a tolerance of 

0.15 ppm for residues in/on the melon subgroup 9A. The number and locations of crop field 

trials are in accordance with OPPTS Guideline 860.1500, and the trials conducted reflect the 

proposed use pattern. Following pre-transplant or preemergence application of a representative 

formulation at ~0.6-1.0x, the combined residues of sulfentrazone, DMS, and HMS were <0.15 

ppm in/on mature cantaloupes. A revised Section F is required since the petitioner has proposed 

a crop subgroup tolerance level of 0.10 ppm.
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Strawberry

47311408.der.doc

IR-4 has submitted field trial data for sulfentrazone on strawberry. Eight strawberry field trials 

were conducted in the United States during the 2003 growing season. Three perennial strawberry

trials were conducted in Zones 2 (NJ; 1 trial), 5 (MI; 1 trial), and 12 (OR; 1 trial). Five annual 

strawberry trials were conducted in Zones 3 (FL; 2 trials), and 10 (CA; 3 trials). Each trial site 

consisted of one untreated plot and two treated plots. Each treated plot received one broadcast 

soil application of a 75% DF formulation of sulfentrazone at pre-plant (annual strawberry crops) 

or during the dormant phase (perennial strawberry crops) at a rate of 0.25-0.26 lb ai/A (1.0x; 

Treatment Plot 2) or 0.38-0.40 lb ai/A (1.6x; Treatment Plot 3), in 20-35 GPA spray volumes, 

without an adjuvant. Mature strawberries were harvested at 56-to 189-day PHIs.

The results of the field trials show that residues of sulfentrazone, DMS, and HMS were each 

<LOQ (0.05 ppm) in/on all samples of strawberry harvested 56-189 days following a single 

broadcast soil application of a 75% DF formulation of sulfentrazone made preplant (annual 

strawberry crops) or during the dormant phase (perennial strawberry crops) at a rate of 0.25-0.26 

lb ai/A (Treatment Plot 2) or 0.38-0.40 lb ai/A (Treatment Plot 3); see Table 11. Total 

sulfentrazone residues were <0.15 ppm in/on all treated samples of strawberry.

Table 11. Summary of Residue Data from Strawberry Field Trials with Sulfentrazone.

Commodity Total Applic. Residue Levels (ppm)

Rate

(lb ai/A)

PHI

(days) n Min. Max. HAFT1 Median Mean Std. Dev.

Proposed Use Pattern: Preemergence application at a maximum seasonal rate of 0.25 lb ai/A

Sulfentrazone

Strawberry 0.25-0.26 16 <0.05 <0.05 <0.05 <0.05 <0.05 --

0.38-0.40

56-189

16 <0.05 <0.05 <0.05 <0.05 <0.05 --

DMS

Strawberry 0.25-0.26 16 <0.05 <0.05 <0.05 <0.05 <0.05 --

0.38-0.40

56-189

16 <0.05 <0.05 <0.05 <0.05 <0.05 --

HMS

Strawberry 0.25-0.26 16 <0.05 <0.05 0.05 0.05 <0.05 --

0.38-0.40

56-189

16 <0.05 <0.05 0.05 0.05 <0.05 --

Total

Strawberry 0.25-0.26 16 <0.15 <0.15 <0.15 <0.15 <0.15 --

0.38-0.40

56-189

16 <0.15 <0.15 <0.15 <0.15 <0.15 --

1 HAFT = highest-average field trial. For calculation of the total residues, HAFT, median, and mean, the LOQ value (<0.05 

ppm) was used for all residues reported as below the LOQ.

Varying degrees of phytotoxicity were reported at the MI trial site and two CA trial sites. At the 

MI trial site, there was a 25-30% reduction in size in Treatment Plot 2 and a 40% reduction 

Treatment Plot 3. At the Salinas, CA trial, a few weeks after application, there were signs of 

phytotoxicity in both treated plots, with the Treatment Plot 3 being more affected. By the end of 

the growing season, the Treatment Plot 2 plants were stunted with 5-8% dead or missing plants 

and the Treatment Plot 3 was 25-30% dead, with the remainder 25% stunted, producing little or 

no fruit. At the Watsonville, CA trial, a few weeks after application, there were signs of similar 

levels of phytotoxicity in both treated plots. By the end of the growing season, the treated plots 

had fewer plants with fruit than the control plot and no mature berries. In addition, the plants 
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

Page 26 of 34

were not uniform. Treatment Plot 3 also had many small plants throughout the plot. No 

phytotoxic effects were noted at the five remaining trials.

Conclusions: The submitted residue data for strawberries are adequate to fulfill data 

requirements. The number and locations of crop field trials are in accordance with OPPTS 

Guideline 860.1500, and the trials conducted reflect the proposed use pattern. The field trial data 

support a tolerance of 0.15 ppm for residues in/on strawberry. The combined residues of 

sulfentrazone, DMS, and HMS were <0.15 ppm in/on mature strawberries following a pre-plant 

or dormant application of a representative sulfentrazone formulation at 1.0-1.6x. A revised

Section F is required since the petitioner has proposed a tolerance level of 0.05 ppm for residues 

in/on strawberries.

Flax

47311407.de1.doc

IR-4 has submitted field trial data for sulfentrazone on flax. Six flax field trials were conducted 

in the United States in Zones 5 (ND; 3 trials) and 7 (SD; 3 trials) during the 2002 growing 

season. Each trial consisted of one untreated and one treated plot. The treated plots received a 

single preemergence broadcast soil application of a 75% DF formulation or a mixture of two 

75% DF formulations of sulfentrazone at a rate of ~0.375 lb ai/A (1.0x), in 18-20 GPA spray

volumes, without an adjuvant. Flax seed was harvested at 111-to 123-day PHIs.

The results of the field trials indicate that residues of sulfentrazone, DMS, and HMS were each 

<LOQ (0.05 ppm) in/on all samples of flax seed harvested 111-123 days after a single 

preemergence broadcast soil application of a 75% DF formulation or mixture of two 75% DF 

formulations of sulfentrazone at a rate of ~0.375 lb ai/A; see Table 12. Total sulfentrazone 

residues were <0.15 ppm in/on all treated samples of flax seed.

Table 12. Summary of Residue Data from Flax Field Trials with Sulfentrazone.

Commodity Total Applic. Residue Levels (ppm)

Rate (lb ai/A)

PHI 

(days) n Min. Max. HAFT1 Median Mean Std. Dev.

Proposed Use Pattern: Preemergence application at a maximum seasonal rate of 0.375 lb ai/A

Sulfentrazone

Flax, seed 0.365-0.383 111-123 12 <0.05 <0.05 <0.05 <0.05 <0.05 --

DMS

Flax, seed 0.365-0.383 111-123 12 <0.05 <0.05 <0.05 <0.05 <0.05 --

HMS

Flax, seed 0.365-0.383 111-123 12 <0.05 <0.05 <0.05 <0.05 <0.05 --

Total

Flax, seed 0.365-0.383 111-123 12 <0.15 <0.15 <0.15 <0.15 <0.15 --

1 HAFT = highest-average field trial. For calculation of the total residues, HAFT, median, and mean, the LOQ value (<0.05 

ppm) was used for all residues reported as below the LOQ.

Conclusions: The submitted residue data for flax are adequate to fulfill the data requirements. 

The number and locations of crop field trials are in accordance with OPPTS Guideline 860.1500, 

and the trials conducted reflect the proposed use pattern. The field trial data will support a 

tolerance of 0.15 ppm for residues in/on flax seed. The combined residues of sulfentrazone, 

DMS, and HMS were <0.15 ppm in/on flax seed following a preemergence application of a 
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

Page 27 of 34

representative sulfentrazone formulation at 1.0x. A revised Section F is required since the 

petitioner has proposed a tolerance for residues in/on flax seed at 0.05 ppm.

860.1520 Processed Food and Feed

Flax

47311407.de2.doc

IR-4 has submitted processing data for sulfentrazone on flax. In one trial conducted in ND 

during the 2002 growing season, flax seed was harvested 123 days following a single 

preemergence broadcast soil application of a 75% DF formulation of sulfentrazone at a rate of 

0.3718 lb ai/A (~1x), without an adjuvant. The harvested flax seeds were processed into meal 

and oil using simulated commercial processing procedures.

The processing study indicates that all residues of sulfentrazone, DMS, and HMS were <LOQ

(0.05 ppm) in flax seed (RAC), meal, and oil; see Table 13. Since all residues were <LOQ, 

processing factors (PF) could not be calculated (NC). It is noted that no phytotoxic effects were 

reported following application of the test substance.

Table 13. Residue Data from a Flax Processing Study with Sulfentrazone.

Processed Commodity Total Rate Sulfentrazone DMS HMS Total

(lb ai/A) 

PHI 

(days) Residues 

(ppm)

PF Residues 

(ppm)

PF Residues 

(ppm)

PF Residues 

(ppm)

PF

Flax, seed (RAC) <0.05 -- <0.05 -- <0.05 -- <0.15 --

Flax, meal <0.05 NC <0.05 NC <0.05 NC <0.15 NC

Flax, oil

0.3718 123

<0.05 NC <0.05 NC <0.05 NC <0.15 NC

Conclusions: The submitted flax processing study is unacceptable for regulatory purposes since 

the study has not conclusively demonstrated that sulfentrazone residues of concern will not 

concentrate in flax meal and oil as a result of the proposed use. Quantifiable residues were not 

detected in the flax seeds used for processing, and the field trial was conducted at only a 1x rate. 

Since no phytotoxic effects were reported, the flax processing study needs to be repeated using 

an exaggerated application rate (equal to the maximum theoretical concentration factor for flax or 

5x, whichever is less).

Tomato

47311405.der.doc

IR-4 has submitted the results of a tomato processing study with sulfentrazone. Samples used for 

processing were generated from a field trial conducted in CA during the 2004 growing season. 

Tomatoes were harvested 20 days following two applications (one banded application to soil 

surface pre-transplant and one postemergence application between rows using a shielded/hooded 

sprayer) of a 4 lb/gal flowable concentrate (FlC) formulation of sulfentrazone, applied at rates of 

~0.250 lb ai/A/application, for a total rate of ~0.500 lb ai/A (~1.3x; Treatment Plot 2) or at 

~0.375 lb ai/A/application, for a total rate of ~0.750 lb ai/A (2.0x; Treatment Plot 3). 

Applications were made at a 99-day RTI, in 25-31 GPA spray volumes, without an adjuvant. 

The collected tomato samples were processed into paste and puree using simulated commercial 
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

Page 28 of 34

procedures.

The processing study indicates that all residues of sulfentrazone, DMS, and HMS were <LOQ

(<0.05 ppm) in/on tomato fruit, paste, and puree; see Table 14. Since all residues were <LOQ, 

processing factors could not be calculated. The study reported that phytotoxic effects occurred 

after the first application but the crops fully recovered by the second application. The maximum 

theoretical concentration factors are 5.5x for processing to tomato paste (OPPTS 860.1520, 

Table 1).

Table 14. Residue Data from a Tomato Processing Study with Sulfentrazone.

Processed Commodity Total Rate Sulfentrazone DMS HMS Total

(lb ai/A) 

PHI 

(days) Residues 

(ppm)

PF Residues 

(ppm)

PF Residues 

(ppm)

PF Residues 

(ppm)

PF

0.5006 <0.05

<0.05

-- <0.05

<0.05

-- <0.05

<0.05

-- <0.15

<0.15

Tomato, fruit (RAC) --

0.7607 <0.05

<0.05

NC

NC

<0.05

<0.05

NC

NC

<0.05

<0.05

NC

NC

<0.15

<0.15

NC

NC

0.5006 <0.05

<0.05

NC

NC

<0.05

<0.05

NC

NC

<0.05

<0.05

NC

NC

<0.15

<0.15

NC

NC

Tomato, paste

0.7607 <0.05

<0.05

NC

NC

<0.05

<0.05

NC

NC

<0.05

<0.05

NC

NC

<0.15

<0.15

NC

NC

0.5006 <0.05

<0.05

NC

NC

<0.05

<0.05

NC

NC

<0.05

<0.05

NC

NC

<0.15

<0.15

NC

NC

Tomato, puree

0.7607

20

<0.05

<0.05

NC

NC

<0.05

<0.05

NC

NC

<0.05

<0.05

NC

NC

<0.15

<0.15

NC

NC

1

For calculation of the total residues, the LOQ value (<0.05 ppm) was used for all residues reported as below the LOQ.

Conclusions: The submitted tomato processing study is unacceptable since the study does not 

conclusively demonstrated that sulfentrazone residues of concern will not concentrate in tomato 

paste and puree as a result of the proposed use. Although the petitioner reported phytotoxic 

effects after the first application, these plants recovered by the second application. Therefore, an 

attempt should be made to apply sulfentrazone at an exaggerated rate (equal to the maximum 

theoretical concentration factor or 5x, whichever is less) to obtain samples with quantifiable 

residues so that processing factors may be determined.

860.1650 Submittal of Analytical Reference Standards

Analytical standards for sulfentrazone and its metabolites DMS and HMS are currently available 

at the EPA National Pesticide Standards Repository (personal communication with Dallas 

Wright, ACB, 4/21/08). However, the standards for sulfentrazone and its metabolite DMS will 

expire 10/1/2012 and 5/1/2012, respectively, and the standard for its metabolite HMS has expired 

4/1/2008. The registrant must 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 COAs are being submitted, they should be faxed to the repository at 

410-305-2999.

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:
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

Page 29 of 34

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.)

860.1850/1900 Confined/Field Accumulation in Rotational Crops

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 

a result of the use on soybeans. As the 1x use rate in soybeans (0.375 lb ai/A) is ≥ 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.

860.1550 Proposed Tolerances

The HED Metabolism Committee has 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 (D226434, 6/14/96, G. 

Kramer). As the enforcement method for plant commodities determines free and conjugated 

forms of the analytes, the tolerance expression should be revised to indicate the residues of 

concern are the combined residues of free and conjugated sulfentrazone, and its metabolites 

HMS and DMS.

Sulfentrazone tolerances are currently established under 40 CFR §180.498. A tolerance is 

established under 40 CFR §180.498(a)(1) for the combined residues of sulfentrazone and its

major metabolite, HMS, in/on soybean seed at 0.05 ppm. Permanent tolerances are established 

under 40 CFR §180.498(a)(2) for the combined residues of sulfentrazone and its metabolites 

HMS and DMS in/on several food commodities; these established tolerances range from 0.15 

ppm (various plant commodities) to 0.40 ppm (peanut meal). Time-limited tolerances for the 

combined residues of sulfentrazone and its metabolites HMS and DMS have been established 

under 40 CFR §180.498(b) in connection with Section 18 Emergency Exemptions; these include 

tolerances for bean, succulent seed without pod (lima bean & cowpea) at 0.1 ppm with a

12/31/07 expiration date, flax seed at 0.2 ppm with a 12/31/10 expiration date, and strawberry at 

0.60 ppm with a 12/31/10 expiration date. Finally, tolerances are established under 40 CFR 

§180.498(d) for inadvertent and indirect combined residues of sulfentrazone and its metabolites 

HMS and DMS in/on cereal grain (excluding sweet corn) bran, forage, grain, hay, hulls, stover, 

and straw at 0.1-0.6 ppm as a result of the application of sulfentrazone to growing crops.

The proposed tolerance expression in the current petition should be revised to indicate tolerances 

for combined residues of free and conjugated sulfentrazone and its metabolites HMS and DMS 

are the residues of concern. 
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

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Pending submission of a revised Section F as specified in Table 15, adequate crop field trial data 

have been submitted for: broccoli, one of the representative commodities of head and stem 

Brassica (subgroup 5A); provided the proposed use directions are modified, mustard greens, the 

sole representative commodity of Brassica leafy greens (subgroup 5B); peas (succulent and 

edible-podded); bell and non-bell peppers and tomatoes, the representative commodities of 

fruiting vegetables (group 8); cantaloupe, the sole representative commodity of melon subgroup 

(subgroup 9A); strawberries; and flax. The submitted data showed that the combined residues of 

sulfentrazone, DMS, and HMS were <0.15 ppm in/on mature commodities listed above 

following application(s) of a representative formulation of sulfentrazone according to the 

proposed crop use pattern. It is, however, noted that higher residues were observed in/on 

mustard green samples treated at <1.0x. The field trial data are supported by adequate storage 

stability data, and no corrections need to be applied on the observed residues. A revised Section 

B must be submitted to remove the proposed postemergence use on fruiting vegetables.

The residue data for mustard greens were not entered into the Agency’s tolerance spreadsheet as 

specified by the Guidance for Setting Pesticide Tolerances Based on Field Trial Data SOP to 

determine the tolerance level as more than half of the samples (8 of 14) had residues that were 

less then the LOQ (0.05 ppm). HED concludes a tolerance level of 0.40 ppm for combined 

residues of free and conjugated sulfentrazone, HMS and DMS in/on Brassica leafy greens, 

subgroup 5B. A revised Section F is required.

The previously reviewed data for potato, the representative commodity of tuberous and corm 

vegetables (subgroup 1C) may be used to support the requested use pattern for the subgroup. 

These data were submitted as part of PP# 2E6405 (DP#s 287102, 1/10/03, G. Kramer) and 

showed that the maximum combined residues of sulfentrazone and its metabolites HMS and 

DMS were 0.077 ppm in/on potato tubers after a preemergence treatment at 1x.

The previously reviewed data for cabbage, another representative commodity of head and stem 

Brassica (subgroup 5A) may be used to support the requested use pattern for the subgroup. 

These data were submitted in conjunction with PP#1E6311 (DP# 276111, 12/9/02, G. Kramer) 

and indicate that the combined residues of sulfentrazone, HMS, and SCA (quantified as DMS) 

were <0.15-0.18 ppm and <0.15-0.17 ppm in/on cabbage heads with and without wrapper leaves, 

respectively, following application at 1x. The petition review concluded that two additional 

cabbage field trials should be conducted in Regions 1 and 8 as a condition for full registration.

These trials are no longer needed since an adequate number of broccoli and cabbage field trials 

are available to satisfy geographic representation for head and stem Brassica, subgroup 5A.

The submitted data for the fruiting vegetables may used to support the proposed use on okra.

New flax and tomato processing studies are required.

No Codex, Canadian, or Mexican MRLs have been established for sulfentrazone on the subject 

crops; therefore, harmonization of MRLs and U.S. tolerances is not an issue at this time. An 

International Residue Limit (IRL) form is appended to this Summary Document and follows this 

section.

A tolerance summary for sulfentrazone is presented in Table 15.
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

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Table 15. Tolerance Summary for Sulfentrazone.

Commodity Proposed Tolerance 

(ppm)

Recommended 

Tolerance (ppm)

Comments

Brassica, head and stem, 

subgroup 5A

0.20 0.20 The established tolerance for 

cabbage under 180.498(a)(2) should 

be removed concomitantly when the 

subgroup 5A tolerance is established

Brassica, leafy greens, 

subgroup 5B

0.35 0.40

Melon subgroup 9A 0.10 0.15

Vegetable, fruiting, group 8 0.05 0.15

Okra 0.05 0.15

Pea, succulent 0.05 0.15

Flax 0.05 0.15 The established time limited 

tolerance for flax seed under 

180.498(b) should be removed 

concomitantly when the permanent 

flax tolerance is established.

Strawberry 0.05 0.15 The established time limited

tolerance for strawberry under 

180.498(b) should be removed 

concomitantly when the permanent 

strawberry tolerance is established.

Vegetable, tuberous and 

corm, subgroup 1C

0.15 0.15 Tolerance recommendation is based 

on residue data translated from 

potato. The established tolerance for 

potato under 180.498(a)(2) should be 

removed concomitantly when the 

subgroup 1C tolerance is established.

References

DP#: 288712

Subject: Sulfentrazone – Briefing Memorandum for Meeting of Metabolism Assessment 

Review Committee

From: G. Kramer

To: Y. Donovan

Dated: 3/6/03

MRID(s): None
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

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DP#s: 287102, 286879, 287256, 287257

Subject: PP#s 2F6391, 2E6498, 2E6405 & 2E6500. Sulfentrazone in/on Dried Shelled Pea 

and Bean, Field Corn, Succulent Lima Bean, Potatoes and Asparagus. Summary

of Analytical Chemistry and Residue Data.

From: G. Kramer

To: D. Morgan/J. Miller

Dated: 1/10/03

MRID(s): 45537402, 45567404, 45739201, 45582201, 45752601, 45567403, 45582201

DP#: 276111

Subject: PP# 1E6311. Sulfentrazone on Cabbage, Horseradish, and Mint. Evaluation of 

Residue Data and Analytical Methods.

From: G. Kramer

To: S. Brothers/R. Forrest

Dated: 12/9/02

MRID(s): 45393501 and 45393502

DP#: 233520

Subject: PP# 4F04407. Sulfentrazone (Authority Herbicide) for Use on Soybeans. Results 

of Petition Method Validation (PMV).

From: G. Kramer

To: S. Robbins/K. Boyle

Dated: 3/25/97

MRID(s): 44118801 and 44118802

DP#: 226434

Subject: HED Metabolism Committee of 5/20/96. Sulfentrazone. PP#4F04407.

From: G. Kramer

To: HED Metabolism Committee Members

Dated: 6/14/96

MRID(s): None

DP#: 220548

Subject: PP# 4F04407. Sulfentrazone for Use on Soybeans. Data Waiver Request.

From: G. Kramer

To: J. Miller

Dated: 3/13/96

MRID(s): None

DP#: None

Subject: Multiresidue Method Testing of sulfentrazone and 3-hydroxy methyl 

sulfentrazone.

From: G. Kramer

To: H. Hundley

Dated: 2/7/95

MRID(s): 43345416
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

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Attachments: 

International Residue Limit Status sheet

DOCUMENT TRACKING

RDI: RAB1 Chemistry Team: 08/20/2008

Petition Number: 7E7308

DP#: 349321

PC Code: 129081

Template Version September 2005
Sulfentrazone Summary of Analytical Chemistry and Residue Data DP#: 349321

Page 34 of 34

INTERNATIONAL RESIDUE LIMIT STATUS

Chemical Name: N-[2,4-

dichloro-5-[4-

(difluoromethyl)-4,5-

dihydro-3-methyl-5-oxo1H-1,2,4-triazol-1-

yl]phenyl]methanesulfona

mide

Common Name: 

Sulfentrazone

X Proposed tolerance

⁬Reevaluated tolerance

⁬Other

Date: 4/17/08

Codex Status (Maximum Residue Limits) U. S. Tolerances

X No Codex proposal step 6 or above

⁬ No Codex proposal step 6 or above for the crops 

requested

Petition Number: PP#7E7308

DP#: 349321

Other Identifier: 

Residue definition (step 8/CXL): N/A Reviewer/Branch: J. Tyler/RAB1

Residue definition: Combined residues of sulfentrazone 

and its metabolites 3-hydroxymethyl sulfentrazone 

(HMS) and 3-desmethyl sulfentrazone (DMS)

Crop (s) MRL (mg/kg) Crop(s) Tolerance (ppm)

Brassica, head and stem, 

subgroup 5A

0.20

Brassica, leafy greens, 

subgroup 5B

0.35

Melon, subgroup 9A 0.10

Vegetable, fruiting, group 8 0.05

Okra 0.05

Pea, succulent 0.05

Flax 0.05

Strawberry 0.05

Vegetable, tuberous and corm, 

subgroup 1C

0.15

Limits for Canada Limits for Mexico

X No Limits

⁬ No Limits for the crops requested

⁬ No Limits

X No Limits for the crops requested

Residue definition: N/A Residue definition: sulfentrazone

Crop(s) MRL (mg/kg) Crop(s) MRL (mg/kg)

Notes/Special Instructions:

S.Funk, 04/28/2008.