Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF 

CHEMICAL SAFETY AND

POLLUTION PREVENTION

MEMORANDUM

Date: 09-FEB-2011

Subject: Pyrasulfotole. Section 3 Request for Use on Sorghum and Grass Grown for 

Seed. Summary of Analytical Chemistry and Residue Data.

PC Code: 000692 DP Barcode: D375391 

Decision No.: 425581 Registration No.: 264-1023

Petition No.: 9F7680 Regulatory Action: Section 3 Registration

Risk Assessment Type: NA Case No.: 7272

TXR No.: None CAS No.: 365400-11-9

MRID No.: 47815001 and 47815002 40 CFR: 180.631

From: Jennifer R. Tyler, Chemist

Risk Assessment Branch (RAB1)

Health Effects Division (HED) (7509P)

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

RAB1/HED (7509P)

To: Bethany Benbow/Joanne Miller, RM Team 23

Registration Division (RD) (7505P)

Bayer CropSciences has submitted a petition for the use of the active ingredient (ai) 

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

(trifluoromethyl)phenyl]methanone) on sorghum and grass grown for seed. Bayer has requested 

the establishment of permanent tolerances for pyrasulfotole and its metabolite, 5-hydroxy-3-

methyl-1H-pyrazol-4-yl)[2-(methylsulfonyl)-4-(trifluoromethyl)phenyl]methanone, in or on the 

following raw agricultural commodities (RACs):

Sorghum, grain 0.8 ppm

Sorghum, forage 1.2 ppm

Sorghum, stover 0.35 ppm

Grass, forage 10 ppm

Grass, hay 2.5 ppm

In addition, Bayer has requested permanent tolerances for pyrasulfotole pyrasulfotole ((5-

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

(trifluoromethyl)phenyl]methanone) in or on the following commodities:
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Milk 0.01 ppm Hog, liver 8 ppm

Cattle, meat 0.04 ppm Hog, meat byproducts 2 ppm

Cattle, fat 0.04 ppm Sheep, meat 0.04 ppm

Cattle, liver 8 ppm Sheep, fat 0.04 ppm

Cattle, meat byproducts 2 ppm Sheep, liver 8 ppm

Goat, meat 0.04 ppm Sheep, meat byproducts 2 ppm

Goat, fat 0.04 ppm Horse, meat 0.04 ppm

Goat, liver 8 ppm Horse, fat 0.04 ppm

Goat, meat byproducts 2 ppm Horse, liver 8 ppm

Hog, meat 0.04 ppm Horse, meat byproducts 2 ppm

Hog, fat 0.04 ppm

Executive Summary

Pyrasulfotole is a postemergence dicot herbicide currently registered for use on small cereal 

grains, including wheat, barley, oat, rye, and triticale.

Pyrasulfotole will be formulated as HuskieTM Herbicide, an emulsifiable concentrate (EC) 

comprised of 37.5 g/L of pyrasulfotole, bromoxynil (present as the mixed heptanoate and 

octanoate esters), and the safener mefenpyr-diethyl for use on grain sorghum and grass grown for 

seed. The EC formulation is being proposed for two ground or foliar applications per season to 

the above crops at rates of 0.073-0.078 lb pyrasulfotole/A. HED notes that this document 

pertains to the ai pyrasulfotole only.

The use directions provided by the petitioner are adequate to allow evaluation of the residue data 

relative to the proposed uses on grain sorghum and grass grown for seed, with the exception of 

instructions for the use of adjuvants and the proposed application type/equipment or spray 

volume for grass grown for seed. The submitted magnitude of the residue studies were 

performed without the use of adjuvants. Therefore, the label should be amended to prohibit 

the use of adjuvants on grain sorghum and grass grown for seed. In addition, the available 

magnitude of residue data support broadcast foliar spray applications, and a spray volume of 10-

24 gal/A. The proposed label should be revised to specify instructions of application 

equipment and spray volume for grass grown for seed.

The nature of the pyrasulfotole residues sorghum and grass is understood based on previously 

submitted and reviewed metabolism studies on wheat (Memo, J. Tyler, 6/8/07; D333412). The 

metabolism of pyrasulfotole in spring wheat involves the demethylation and subsequent 

glucosylation of the parent compound, yielding pyrasulfotole-desmethyl-O-glucoside. There 

was also cleavage of the complete pyrazole moiety resulting in the pyrasulfotole-benzoic acid 

metabolite. Based on the results of the wheat metabolism studies, parent and pyrasulfotoledesmethyl are the residues of concern for tolerances and risk assessment purposes (Memo, J. 

Tyler et al., 06/08/07; D328640). Any future uses on other crops, such as leafy vegetables, or 

legumes, may require the submission of additional metabolism data.

The nature of the pyrasulfotole residues in livestock is understood based on previously submitted 

and reviewed lactating goat and laying hen metabolism studies (Memo, J. Tyler, 6/8/07; 

D333412). The goat study indicates that the metabolism of pyrasulfotole in lactating goats 

involved either N-demethylation of pyrasulfotole to form pyrasulfotole-desmethyl, or oxidation 

of pyrasulfotole to form pyrasulfotole-hydroxymethyl. The hen study indicates that the 
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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metabolism of pyrasulfotole in laying hens involved the N-demethylation of pyrasulfotole to 

yield the pyrasulfotole-desmethyl metabolite. The residues of concern in livestock for tolerance 

and risk assessment purposes are parent and the desmethyl metabolite (Memo, J. Tyler, 06/08/07; 

D328640).

An adequate high-performance liquid chromatography (HPLC)/mass spectrometry (MS)/MS 

method (Method AI-001-P04-02) is available for collecting data on residues of pyrasulfotole and 

its metabolite pyrasulfotole-desmethyl in/on plant commodities. The limit of quantitation (LOQ) 

is 0.010 ppm for each analyte. A similar method, Method AI-001-P04-01, which is also the 

proposed enforcement method for plant commodities, has been adequately radiovalidated and 

undergone a successful independent laboratory validation (ILV) trial. Method AI-001-P04-01 

was forwarded to the Analytical Chemistry Branch of the Biological & Economics Analysis 

Division (ACB/BEAD) for a petition method validation (PMV; Memo, J. Tyler, 1/30/07; 

D335558). ACB reviewed the proposed enforcement method data without a laboratory

validation, but recommended the petitioner provide information for a second MS/MS ion 

transition to provide a confirmation of analyte identities (Memo, C. Stafford, 6/7/07; D335559). 

In response, the company submitted Bayer Method AI-001-P04-02, which includes the requested 

information for a second MS/MS ion transition. HED reviewed this method, and determined it 

suitable for determination of pyrasulfotole and pyrasulfotole-desmethyl in crop matrices (Memo, 

G. Kramer, 12/18/09; D367796).

A HPLC-MS/MS method (Method AI-004-A05-01) for collecting data on pyrasulfotole in 

livestock tissues, including milk, matrices was previously submitted and reviewed by HED 

(Memo, J. Tyler, 06/08/07; D333412). However, based on the results of the livestock 

metabolism studies, the residues of concern in livestock are pyrasulfotole and pyrasulfotoledesmethyl for tolerance and risk assessment purposes (Memo, J. Tyler et al., 6/8/07; D328640). 

Therefore, HED requested the petitioner submit a ruminant analytical enforcement method to 

determine residues of pyrasulfotole and pyrasulfotole-desmethyl as well as adequate

radiovalidation and ILV data. In response, the company submitted a new HPLC-MS/MS 

(Method AI-006-A08-01) for collecting pyrasulfotole and pyrasulfotole-desmethyl in livestock 

tissues and milk, as well as ILV data. HED reviewed these submissions; and, based on 

validation data provided by the petitioner and the successful ILV, determined that Method AI006-A08-01 is suitable as an enforcement method for livestock commodities as defined in 

Standard Operating Procedure (SOP) No. ACB-019 (9/15/08) (Memo, G. Kramer, 12/18/09; 

D367796). HED also determined that radiovalidation data are not necessary as the extraction 

procedures are identical to the previous version of the method (for which adequate extraction 

efficiency data were provided).

Pyrasulfotole and the metabolite pyrasulfotole-desmethyl were subjected to analysis by selected 

Protocols of the Food and Drug Administration (FDA) Pesticide Analytical Manual, Volume I 

(PAM I), third edition. The results indicate that pyrasulfotole is partially recovered through 

Protocol B, and completely recovered through Protocol C module DG-17. Pyrasulfotoledesmethyl was not recovered through any of the Protocols. The report has been forwarded to 

FDA for inclusion in PAM I (Memo, J. Tyler, 1/30/07; D335562). 

No storage stability data were submitted in conjunction with the proposed uses. The available 

storage stability data are acceptable and indicate that residues of pyrasulfotole and pyrasulfotolebenzoic acid are stable in soybean seed and wheat matrices for up to 11 months, and residues of 

pyrasulfotole-desmethyl decline in wheat forage and hay (ca. 0.12% per day) in frozen storage. 
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The storage stability data support the sample storage intervals and conditions in the submitted 

crop field trials. Corrections to residues of pyrasulfotole due to in-storage dissipation are not 

necessary, but residues of pyrasulfotole-desmethyl in sorghum forage and stover, and grass

forage and hay will require corrections for in-storage dissipation.

The results of the cattle feeding study are adequate for purposes of this action. HED assumed the 

transfer of pyrasulfotole-desmethyl from plant to livestock to be equivalent to that of the parent 

pyrasulfotole based on the similar structure. For any new uses which significantly increase the 

maximum reasonable dietary burden (MRDB) of the metabolite, the petitioner may be required 

to submit a feeding study with pyrasulfotole-desmethyl.

Based on the MRDB for dairy cattle (45 ppm), the actual dose levels in the feeding study are 

equivalent to 0.067x, 0.2x, and 0.67x the MRDB for dairy cattle. Based on the residues at the 

0.67x feeding level, the current tolerances of 0.02 ppm for meat of cattle, goat, horse and sheep 

are adequate to support the proposed uses. However, tolerances should be established for 

residues of pyrasulfotole and pyrasulfotole-desmethyl in/on milk at 0.03 ppm; fat of cattle, goat, 

horse and sheep at 0.03 ppm; liver of cattle, goat, horse, and sheep at 3.0 ppm; and meat 

byproducts, except liver, of cattle, goat, horse, and sheep at 0.70 ppm. A revised Section F 

should be submitted to include the above tolerances, as well as correct commodity 

definitions and tolerance expression for livestock commodities.

Based upon a MRDB of 0.56 ppm for hogs, there is no reasonable expectation of finding 

quantifiable residues of pyrasulfotole and pyrasulfotole-desmethyl in hog muscle and fat; thus, 

the current tolerances of 0.02 ppm are adequate. There is reasonable expectation of residues of 

pyrasulfotole and pyrasulfotole-desmethyl in hog liver and kidney. Therefore, the following 

tolerances for residues of pyrasulfotole and pyrasulfotole-desmethyl are necessary: hog, meat 

byproducts, except liver at 0.05 ppm; and hog, liver at 0.30 ppm. A revised Section F should 

be submitted to include the above tolerances, as well as correct commodity definitions and 

tolerance expression for livestock commodities.

The results of the poultry feeding study are inadequate to determine the need for poultry

tolerances as only residues of pyrasulfotole-benzoic acid were measured in the study. However, 

the results of the poultry metabolism studies can be used to determine the need for a new poultry

feeding study and/or poultry tolerances. Based on the MRDB of 0.52 ppm for poultry, the 

phenyl-labeled (8.6 ppm) and pyrazole-labeled (10.5 ppm) poultry metabolism studies were 

conducted at 16x and 20x the MRDB for poultry, respectively. Based on the results of the 

poultry metabolism study, there is no reasonable expectation of finding quantifiable residues of 

pyrasulfotole and pyrasulfotole-desmethyl in eggs and poultry muscle and fat; thus, the current 

tolerances of 0.02 ppm for residues of pyrasulfotole and pyrasulfotole-desmethyl in fat, meat, 

and meat byproducts of poultry are adequate. There is reasonable expectation of residues of 

pyrasulfotole and pyrasulfotole-desmethyl in poultry meat byproducts. Therefore, a tolerance of 

0.20 ppm for residues of pyrasulfotole and pyrasulfotole desmethyl in poultry byproducts is 

necessary. A revised Section F should be submitted to include the above tolerances and 

correct tolerance expression for livestock commodities.
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The available grain sorghum and grass residue data are classified as scientifically acceptable for 

determination of the magnitude of residue for and the metabolite pyrasulfotole-desmethyl when 

treated with the end use products HuskieTM Herbicide. As the number and geographical 

representation of the grain sorghum and grass trials are appropriate, the residue data are adequate 

to support the proposed uses.

The grain sorghum crop field trial data support a maximum seasonal application rate of 0.078

pound (lb) ai/acre (A) (~1x the maximum proposed application rate) on sorghum forage, grain, 

and stover [preharvest interval (PHI) of 5-7 days for forage, 60 days for grain and stover]. With 

these use patterns, total residues of pyrasulfotole and pyrasulfotole-desmethyl are not expected to 

exceed 0.902 ppm (forage, 7-day PHI), 0.325 ppm (grain), and 0.420 ppm (stover). Using the 

North American Free Trade Agreement (NAFTA) Maximum Residue Limit (MRL)/Tolerance 

Harmonization Workgroup methodology for forage, grain, and stover; the available grain 

sorghum crop field trial data indicate that the appropriate tolerances for residues of pyrasulfotole 

and pyrasulfotole-desmethyl in/on grain sorghum commodities are 1.5 ppm for sorghum, grain, 

forage; 0.70 ppm for sorghum, grain, grain; and 0.80 ppm for sorghum, grain, stover. Section F 

of the petition should be revised to include the aforementioned HED-recommended 

tolerances and the correct commodity definitions for grain sorghum RACs.

The grass crop field trial data support a maximum seasonal application rate of 0.076-0.091 lb 

ai/A (~1x the maximum proposed application rate) on grass forage and hay (PHI of 7 days for 

forage, and 30 days hay). With these use patterns, total pyrasulfotole and pyrasulfotoledesmethyl residue levels are not expected to exceed 6.52 ppm (forage, 7-day PHI) and 2.31 ppm 

(hay). Using the NAFTA MRL/Tolerance Harmonization Workgroup methodology for forage

(7-day PHI) and hay, the available grass crop field trial data indicate that the appropriate 

tolerances for residues of pyrasulfotole and pyrasulfotole-desmethyl in/on grass commodities are 

25 ppm for grass, forage; and 3.5 ppm for grass, hay. Section F of the petition should be 

revised to include the aforementioned HED-recommended tolerances.

No rotational crop data were submitted in conjunction with the proposed uses. Adequate 

confined and field rotational crop data have been submitted by the petitioner and reviewed by 

HED in conjunction with PP#6F7509 (Memo, J. Tyler, 6/8/07; D366490). The results of the 

submitted confined and limited field rotational crop studies together are adequate to determine 

appropriate plantback intervals (PBIs) for rotational crops. In addition, HED approved a 

requested to revise the Crop Rotation Guidelines on the currently approved HuskieTM Herbicide 

(EPA Reg. No. 264-1023). The submitted confined and limited field trial data support the 

proposed PBIs.

HED Conclusion/Recommendations

Provided 1) Section B is revised to include a prohibition on the use of adjuvants on grain 

sorghum and grass grown for seed and instructions of application equipment and spray volume 

for grass grown for seed; 2) Section F is revised to the HED-recommended tolerances, as well as 

correct commodity definitions and tolerance expressions; and 3) analytical reference standards 

for pyrasulfotole-desmethyl and labeled internal standards are submitted to the EPA National 

Pesticide Standards Repository, the residue chemistry database supports the establishment of an 

unconditional registration and permanent tolerances as listed below.
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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Tolerances are established for residues of the herbicide pyrasulfotole, 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 pyrasulfotole ((5-

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

(trifluoromethyl)phenyl]methanone) and its desmethyl metabolite (5-hydroxy-3-methyl-1Hpyrazol-4-yl)[2-(methylsulfonyl)-4-(trifluoromethyl)phenyl]methanone), calculated as the 

stoichiometric equivalent of pyrasulfotole, in or on the following commodities:

Sorghum, grain, grain 0.70 ppm Hog, fat* 0.02 ppm

Sorghum, grain, forage 1.5 ppm Hog, liver 0.30 ppm

Sorghum, grain, stover 0.80 ppm Hog, meat byproducts, except liver 0.05 ppm

Grass, forage 25 ppm Sheep, meat* 0.02 ppm

Grass, hay 3.5 ppm Sheep, fat 0.03 ppm

Milk 0.03 ppm Sheep, liver 3.0 ppm

Cattle, meat* 0.02 ppm Sheep, meat byproducts, except liver 0.70 ppm

Cattle, fat 0.03 ppm Horse, meat* 0.02 ppm

Cattle, liver 3.0 ppm Horse, fat 0.03 ppm

Cattle, meat byproducts, except liver 0.70 ppm Horse, liver 3.0 ppm

Goat, meat* 0.02 ppm Horse, meat byproducts, except liver 0.70 ppm

Goat, fat 0.03 ppm Poultry, meat* 0.02 ppm

Goat, liver 3.0 ppm Poultry, fat* 0.02 ppm

Goat, meat byproducts, except liver 1.0 ppm Poultry, meat byproducts 0.20 ppm

Hog, meat* 0.02 ppm Eggs* 0.02 ppm

* The recommended tolerances for these commodities are at the same level as the current tolerances under 40 CFR 180.631.

A human-health risk assessment will be prepared as a separate document.

Background

Pyrasulfotole is a postemergence dicot herbicide currently registered for use on small cereal 

grains, including wheat, barley, oat and triticale. Pyrasulfotole is an effective inhibitor of the 

enzyme 4-hydroxyphenylpyruvate dioxygenase (HPPDase) and consequently blocks the pathway

of prenylquinone biosynthesis in plants. The end-use products are applied to the target weeds 

and act primarily through leaf uptake and translocation to the target site. The first symptoms 

appear three to five days after application. Bleaching and discoloration appear initially and 

symptoms progress to tissue necrosis and plant death within two weeks. 

HuskieTM Herbicide is an EC mixture containing pyrasulfotole, bromoxynil, and mefenpyr-diethyl 

safener. The nomenclature and physicochemical properties of pyrasulfotole are presented below 

in Tables 1 and 2.
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Table 1. Test Compound and Metabolite Nomenclature.

Compound Chemical Structure

Common name Pyrasulfotole

Company Experimental name AE 0317309

IUPAC name 5-hydroxy-1,3-dimethylpyrazol-4-yl 2-mesyl-4-(trifluoromethyl)phenyl ketone

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

(trifluoromethyl)phenyl]methanone

CAS # 365400-11-9

End-use products (EPs) AE 0317309 SE06 Herbicide and AE 0317309 +Bromo Herbicide

Compound Chemical Structure

S O

F3C

O O

N

N

HO

H

Common name Pyrasulfotole-desmethyl

Company Experimental name AE 1073910

CAS name (5-hydroxy-1H-pyrazol-4-yl)[2-mesyl-4-(trifluoromethyl)phenyl]methanone

Table 2. Physicochemical Properties of the Technical Grade Test Compound.

Parameter Value Reference

Melting point Pure: 201°C

No boiling point, decomposition starts at 245°C

MRID 

46801701

pH at 22.9°C 3.03

Density 1.53

Water solubility (g/L at 20C) 2.3

4.2 

69.1 

49.0

pH 3.0 (distilled water)

pH 3.9 (buffer pH 4.0)

pH 5.4 (buffer pH 7.0)*

pH 5.2 (buffer pH 9.0)*

* exceeded buffer capacity

Solvent solubility (g/L at 20C) Ethanol 

n-Hexane

Tolune

Dichloromethane

Acetone

Ethyl acetate

Dimethyl sulfoxide

21.6

0.038

6.86

120-150

89.2

37.2

≥ 600

Vapor pressure at 20C 2.7 X 10-7

Pa

Dissociation constant (pKa) 4.2

n-octanol-water partition coefficient 

Log(KOW) at 23°C

0.276

-1.362

-1.580 

pH 4.0

pH 7.0

pH 9.0

UV/visible absorption spectrum max= 264, 241, 216 nm in water, 0.1M HCl, 0.1M NaOH respectively.

N

N

F3C

S O

O

HO

O
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860.1200 Directions for Use

Pyrasulfotole will be formulated as HuskieTM Herbicide, an EC formulation containing 0.31 lb 

ai/gal pyrasulfotole, bromoxynil (present as the mixed heptanoate and octanoate esters), and the 

safener mefenpyr-diethyl for use on grain sorghum and grass grown for seed. The following 

rotational crop restrictions are listed on the proposed label: 1 month for wheat, barley, oats, rye 

and triticale; 4 months for alfalfa, millet, sorghum (grain), and soybeans; and 9 months for 

canola, canaryseed, chickpeas, corn, dry beans, flax, field peas, green beans, green peas, lentils 

(for all states except 18 months in MN, MT, ND, and SD), mustards, potatoes, safflower, 

sunflowers, and sugar beets. Where not specified, the label requires a field bioassay be 

conducted in order to determine if crop can be successfully rotated with pyrasulfotole. A 

minimum 30-day PBI is required for all crops. Table 3 is a summary of the proposed use 

patterns. 

Table 3. Summary of Proposed Use Patterns.

Crops Product

(EPA Reg. No.)

Application 

Timing; Type; 

and Equip.

# 

App.

Application 

Rate

(lb ai/A) RTI1

(days)

PHI1

(days) Restrictions

Per 

app.

Per 

season

Sorghum HuskieTM 

Herbicide (EPA 

Reg. No. 264-

1023)

Crop application –

apply between 3-

leaf stage of 

growth up to 12 

inches.

Ground equipment

as a foliar spray.

2 0.039 0.078 11 Forage – 7 

days; grains 

or stover –

60 days

Apply in 10-15 

gal of water/A.

Grass grown 

for seed

HuskieTM 

Herbicide (EPA 

Reg. No. 264-

1023)

Crop application –

apply to actively 

growing grass

between 3-leaf 

stage up to 12 

inches.

2 0.036 0.073 30 forage – 7 

days; hay –

30 days

1 RTI = retreatment interval; PHI = preharvest interval; NA = not applicable.

HED Conclusions: The use directions provided by the petitioner are adequate to allow 

evaluation of the residue data relative to the proposed uses on grain sorghum and grass grown for 

seed, with the exception of instructions for the use of adjuvants and the proposed application 

type/equipment or spray volume for grass grown for seed. The submitted magnitude of residue 

studies were performed without the use of adjuvants. Therefore, the label should be amended 

to prohibit the use of adjuvants on grain sorghum and grass grown for seed. In addition, the 

available magnitude of residue data support broadcast foliar spray applications, and a spray

volume of 10-24 gal/A. The proposed label should be revised to specify instructions of 

application equipment and spray volume for grass grown for seed.

860.1300 Nature of the Residue - Plants

Data concerning the metabolism of pyrasulfotole in spring wheat were submitted and reviewed 

in conjunction with PP#6F7509 (Memo, J. Tyler, 6/8/07; D333412). A total of three studies 

were submitted, including a phenyl-labeled study (MRID 46801749), a pyrazole-labeled study 

(MRID 46801748), and a phenyl-labeled study comparing the nature of the residue in spring 

wheat with and without the safener (MRID 46801801). The available wheat metabolism studies 

are adequate, and indicate that the metabolism of pyrasulfotole in spring wheat involves the 
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demethylation and subsequent glucosylation of the parent compound, yielding pyrasulfotoledesmethyl-O-glucoside. There was also cleavage of the complete pyrazole moiety resulting in 

the pyrasulfotole-benzoic acid metabolite as detected by the phenyl-label study and polar fraction 

(p1) formed from the pyrazole-label study. Fraction p1 was characterized as being natural or 

incorporated into the matrix. Based on the results of the wheat metabolism studies, parent and 

pyrasulfotole-desmethyl are the residues of concern for tolerances and risk assessment purposes 

(Memo, J. Tyler et al., 06/08/07; D328640). This conclusion applies to the use of pyrasulfotole 

on grain sorghum and grass grown for seed. However, any future uses on other crops, such as 

leafy vegetables, or legumes, may require the submission of additional metabolism data.

860.1300 Nature of the Residue - Livestock

Data concerning the metabolism of pyrasulfotole in ruminants (lactating goat) and poultry

(laying hen) were submitted and reviewed in conjunction with PP#6F7509 (Memo, J. Tyler, 

6/8/07; D333412). The nature of the pyrasulfotole residues in livestock is understood based on 

the acceptable phenyl- and pyrazole-labeled lactating goat and laying hen metabolism studies. 

The goat study indicates that the metabolism of pyrasulfotole in lactating goats involved either 

N-demethylation of pyrasulfotole to form pyrasulfotole-desmethyl, or oxidation of pyrasulfotole 

to form pyrasulfotole-hydroxymethyl. The hen study indicates that the metabolism of

pyrasulfotole in laying hens involved the N-demethylation of pyrasulfotole to yield the 

pyrasulfotole-desmethyl metabolite. The residues of concern in livestock for tolerance and risk 

assessment purposes are parent and the desmethyl metabolite (Memo, J. Tyler, 06/08/07; 

D328640).

860.1340 Residue Analytical Method – Plants

In the grain sorghum and grass grown for seed magnitude of residue studies, residues of 

pyrasulfotole and its metabolite pyrasulfotole-desmethyl quantitated using Bayer Method AI001-P04-01, an LC-MS/MS using the stable isotopically labeled analytes as internal standards. 

The lowest limit of method validation (LLMV) for each analyte was 0.01 ppm in all matrices. 

The method is acceptable based on concurrent recoveries. All residues were reported in parent 

equivalents.

Bayer Method AI-001-P04-01, an HPLC-MS/MS method, has been adequately radiovalidated 

and has undergone a successful ILV trial. The proposed method was forwarded to ACB/BEAD 

for a PMV (Memo, J. Tyler, 1/30/07; D335558). ACB reviewed the proposed enforcement 

method data without a laboratory validation, but recommended the petitioner provide 

information for a second MS/MS ion transition to provide a confirmation of analyte identities

(Memo, C. Stafford, 6/7/07; D335559). In response, the company submitted Bayer Method AI001-P04-02 (MRID 47806401), which includes the requested information for a second MS/MS 

ion transition. HED reviewed this method, and determined it suitable for determination of 

pyrasulfotole and pyrasulfotole-desmethyl in crop matrices (Memo, G. Kramer, 12/18/09; 

D367796).
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860.1340 Residue Analytical Method – Livestock

A HPLC-MS/MS method (Method AI-004-A05-01) for collecting data on pyrasulfotole in 

livestock tissues, including milk, matrices was previously submitted and reviewed by HED 

(Memo, J. Tyler, 06/08/07; D333412). However, based on the results of the livestock 

metabolism studies, the residues of concern in livestock are pyrasulfotole and pyrasulfotoledesmethyl for tolerance and risk assessment purposes (Memo, J. Tyler et al., 6/8/07; D328640). 

Therefore, HED requested the petitioner submit a ruminant analytical enforcement method to 

determine residues of pyrasulfotole and pyrasulfotole-desmethyl as well as adequate 

radiovalidation and ILV data. In response, the company submitted a new HPLC-MS/MS 

(Method AI-006-A08-01) for collecting pyrasulfotole and pyrasulfotole-desmethyl in livestock 

tissues and milk (MRID 47860002), as well as ILV data (MRID 47860003). HED reviewed 

these submissions; and, based on validation data provided by the petitioner and the successful 

ILV, determined that Method AI-006-A08-01 is suitable as an enforcement method for livestock 

commodities as defined in SOP No. ACB-019 (9/15/08) (Memo, G. Kramer, 12/18/09; 

D367796). HED also determined that radiovalidation data are not necessary as the extraction 

procedures are identical to the previous version of the method (for which adequate extraction 

efficiency data were provided).

860.1360 Multiresidue Methods (MRM)

Bayer CropScience previously submitted adequate MRM recovery data for pyrasulfotole and the 

metabolite pyrasulfotole-desmethyl through FDA Protocols A through E (Memo, J. Tyler, 

06/08/07; D328640). Pyrasulfotole and the metabolite pyrasulfotole-desmethyl were subjected 

to analysis by selected Protocols of the FDA PAM I, third edition. Pyrasulfotole and 

pyrasulfotole-desmethyl were tested according to Protocols A, B, and C of the FDA PAM I 

testing procedures. The results of the MRM analysis indicate that pyrasulfotole is partially

recovered through Protocol B, and completely recovered through Protocol C module DG-17. 

Pyrasulfotole-desmethyl was not recovered through any of the Protocols. The report has been 

forwarded to FDA for inclusion in PAM I (Memo, J. Tyler, 1/30/07; D335562). 

860.1380 Storage Stability

No storage stability data were submitted in conjunction with the proposed uses. The results of a 

study to determine freezer storage stability of pyrasulfotole, pyrasulfotole-desmethyl, and 

pyrasulfotole-benzoic acid in soybean and wheat matrices have been submitted and reviewed by

HED (Memo, J. Tyler, 06/08/07; D328640). The data are acceptable and indicate that residues 

of pyrasulfotole and pyrasulfotole-benzoic acid are stable in soybean seed and wheat matrices for 

up to 11 months, and residues of pyrasulfotole-desmethyl decline in wheat forage and hay (ca. 

0.12% per day) in frozen storage. The storage stability data support the sample storage intervals 

and conditions in the submitted crop field trials.

Sorghum: In the grain sorghum magnitude of residue studies, the maximum frozen storage 

interval from sampling to extraction of pyrasulfotole was 398 days for forage and 309 days for 

grain and stover. For sorghum forage, some samples from the crop field trial were stored for 

approximately 13 months, which is 2 months longer than the storage duration used in the wheat 

storage stability study. However, it is unlikely that a 13-month storage stability study within the 
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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same cereal grain crop group would differ significantly from the currently available 11-month 

wheat study. Residues of the metabolite, pyrasulfotole-desmethyl, were stable in wheat grain. 

Pyrasulfotole desmethyl residues were found to decline in wheat forage and hay at 

approximately 0.12% per day. Therefore, pyrasulfotole-desmethyl residue values in grain 

sorghum forage samples were corrected for 46.3% decline based on wheat forage data and 

pyrasulfotole-desmethyl residue values in grain sorghum stover were corrected for 46.5% decline 

based on wheat hay data.

Grass: In the grass magnitude of residue study, the maximum frozen storage interval from 

sampling to extraction prior to analysis of pyrasulfotole was 349 days for grass forage and 312 

days for grass hay. It should be noted that some grass forage samples were stored for 

approximately 2 weeks longer than the length of the storage stability wheat study. However, it is 

unlikely that storage stability study extended by 2 weeks would differ significantly from the 

currently available 11-month wheat study. Residues of the metabolite, pyrasulfotole-desmethyl, 

however, were found to decline in wheat forage and wheat hay at approximately 0.12% per day. 

Therefore, pyrasulfotole-desmethyl residue values in grass forage samples were corrected for 

46.3% decline based on wheat forage data and pyrasulfotole-desmethyl residue values in grass 

hay were corrected for 46.5% decline based on wheat hay data.

860.1480 Meat, Milk, Poultry, and Eggs

Table 4. Calculation of MRDB of Cattle for Pyrasulfotole.

Feed Commodity Feedstuff Type1 % Dry Matter2 % Diet2

Proposed or 

Recommended 

Tolerances (ppm)

MRDB (ppm)3

Beef/Dairy Cattle (R=15/45%; CC=80/45%; PC=5/10%)

Barley grain CC 88 35/0 0.02 0.0080/0

Aspirated grain fractions CC 85 5/0 0.40 0.023/0

Sorghum grain CC 86 40/45 0.70 0.33/0.37

Sorghum forage R 35 15/0 1.5 0.64/0

Grass forage R 25 0/45 25 0/45

Untreated PC NA 5/10 NA -0-

Total 1.0/45

Poultry (CC=75-80%; PC=20-25%)

Sorghum grain CC - 75 0.70 0.52

Oat grain CC - 5 0.08 0.004

Untreated PC - 20 NA -0-

Total 0.52

Hogs (CC=80-85%; PC=15-20%)

Sorghum grain CC - 80 0.70 0.56

Wheat milled byproducts CC - 5 0.02 0.0005

Untreated PC - 15 NA -0-

Total 0.56

1 CC = carbohydrate concentrate; R = roughage; PC = protein concentrate.

2 Table 1 (860.1000 OPPTS Test Guidelines; June 2008 Revisions of Livestock Diets Percents Reasonable Balanced Diets.

3 Contribution = [tolerance /% DM (if cattle)] X % diet.

Ruminants: No ruminant feeding study was submitted with the subject petition. Permanent 

tolerances have been established for residues of pyrasulfotole and its metabolite pyrasulfotoledesmethyl in/on the following livestock commodities: fat and meat of cattle, goats, hogs, horses 

and sheep at 0.02 ppm; liver of cattle, goats, hogs, horses and sheep at 0.35 ppm; meat 

byproducts, except liver, of cattle, goats, hogs, horses and sheep at 0.06 ppm; and milk at 0.01 

ppm (Memo, J. Tyler, 06/08/07; D328640). The results of a ruminant feeding study was 

submitted and reviewed by HED in the 06/08/07 memo. From the results of that study, HED 
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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estimated the MRDB using HED-recommended pyrasulfotole tolerances. HED calculated that 

the total dietary burden from the worst-case diet calculated for dairy cattle was approximately

0.39 ppm and consisted of 20% wheat hay (dietary burden = 0.18 ppm), 25% wheat forage 

(dietary burden = 0.20 ppm), 45% barley grain (dietary burden = 0.01 ppm), 10% untreated. The 

total dietary burden from the worst case diet for beef cattle was approximately 0.18 ppm and 

consisted of 15% wheat forage (dietary burden = 0.14 ppm), 50% barley grain (dietary burden = 

0.01 ppm), 25% wheat grain (dietary burden = 0.006 ppm); 5% aspirated grain fractions (dietary

burden = 0.02 ppm); and 5% untreated. Based on these results, and in order to harmonize with 

PMRA, the aforementioned tolerances were established.

The ruminant feed items associated with the subject petition are sorghum grain, forage, and 

stover; and grass forage and hay. HED recalculated the MRDB for beef and dairy cattle to 

include these new uses (see Table 4). The results of a dairy cattle feeding study for pyrasulfotole 

have been submitted and reviewed by HED (Memo, J. Tyler, 6/8/07; D333412). 

Based on the results of the livestock metabolism studies, the residues of concern in livestock are 

pyrasulfotole and pyrasulfotole-desmethyl for tolerance and risk assessment purposes (Memo, J. 

Tyler, 06/08/07; D328640). However, only pyrasulfotole was analyzed for in the available dairy

cattle feeding study. HED previously assumed the transfer of pyrasulfotole-desmethyl from 

plants to livestock to be equivalent to that of the parent pyrasulfotole based on the structure 

similarity and concluded that the available dairy cattle feeding study was thus adequate for 

tolerance-setting purposes. As the doses used in the dairy cattle feeding study still bracket the 

MRDB and pyrasulfotole-desmethyl comprised only ~15% of the total residue, HED concludes 

that this feeding study is still adequate for tolerance-setting purposes. However, for any new 

uses which significantly increase the MRDB of pyrasulfotole-desmethyl, the petitioner may be 

required to submit a feeding study in with the desmethyl metabolite.

In that study, dosing was conducted at 0 (control), 3, 9, or 30 ppm/day in the feed (dry weight 

basis); these levels were at 0.067x, 0.2x, and 0.67x the MRDB to dairy cattle. The 0.67x feeding 

level is closest to the actual feeding level of 1x; therefore, it will be used to determined 

appropriate tolerances for ruminant commodities (see Table 5).

Table 5. Determination of Appropriate Tolerance for Ruminant Commodities.

Matrix

Feeding Level

(ppm/day)

[exaggeration]1

Residues (ppm)

Max Residues in 

Feeding Study

Residues When 

Extrapolated to 1x

Recommended 

Tolerance (ppm)

Milk 30 [0.67x] 0.0134 0.0200 0.03

Milk Fat 30 [0.67x] 0.0085 0.0127 0.02

Fat 30 [0.67x] 0.0143 0.0213 0.03

Kidney 30 [0.67x] 0.4144 0.618 0.70

Liver 30 [0.67x] 1.939 2.89 3.0

Muscle 30 [0.67x] 0.0039 0.00582 0.02

1

 From previously reviewed lactating dairy cattle feeding study (46801824.der.doc; Memo, J. Tyler, 6/8/07; D333412). 

Residues of pyrasulfotole were ≤0.0134 ppm in milk and≤0.0085 (<LOQ) in milk fat, resulting 

in residues of 0.0200 ppm and 0.0127 ppm, respectively, when extrapolated to 1x. Residues of 

pyrasulfotole in were ≤0.0010 ppm (<LOQ) muscle and ≤0.0062 ppm (<LOQ) in fat, resulting in

residues of 0.00582 ppm and 0.0213 ppm, respectively, when extrapolated to 1x. Residues of 

pyrasulfotole were ≤1.939 ppm in liver and ≤0.4144 ppm in kidney, resulting in residues of 2.89 

ppm and 0.618 ppm, respectively, when extrapolated to 1x. Based on these residues, the current 

tolerances of 0.02 ppm for meat of cattle, goat, horse and sheep are adequate to support the 
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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proposed uses. However, tolerances should be established for residues of pyrasulfotole and 

pyrasulfotole-desmethyl in/on milk at 0.03 ppm; fat of cattle, goat, horse and sheep at 0.03 ppm; 

liver of cattle, goat, horse, and sheep at 3.0 ppm; and meat byproducts, except liver, of cattle, 

goat, horse, and sheep at 0.70 ppm. A revised Section F should be submitted to include the 

above tolerances, as well as correct commodity definitions and tolerance expression.

Based upon a MRDB of 0.56 ppm for hogs, the 3-ppm feeding level in the ruminant feeding 

study is equivalent to 5.3x the MRDB for hogs. At the 5.3x feeding level, the maximum 

pyrasulfotole residues were 0.0010 ppm in muscle, 0.2224 ppm in kidney, 1.230 ppm in liver, 

and 0.0062 ppm in fat. Residues at the 1x feeding level would be 0.00019 ppm in muscle, 0.042 

ppm in kidney, 0.23 ppm in liver, and 0.0012 ppm in fat. There is no reasonable expectation of 

finding quantifiable residues of pyrasulfotole and pyrasulfotole-desmethyl in hog muscle and fat; 

thus, the current tolerances of 0.02 ppm are adequate. There is reasonable expectation of 

residues of pyrasulfotole and pyrasulfotole-desmethyl in hog liver and kidney. Therefore, the 

following tolerances for residues of pyrasulfotole and pyrasulfotole-desmethyl are necessary: 

hog, meat byproducts, except liver at 0.05 ppm; and hog, liver at 0.30 ppm. A revised Section F 

should be submitted to include the above tolerances, as well as correct commodity 

definitions and tolerance expression.

Poultry: No poultry feeding study was submitted with the subject petition. Permanent 

tolerances have been previously established for residues of pyrasulfotole per se in/on meat, fat 

and meat byproducts of poultry at 0.02 ppm; and egg at 0.02 ppm (Memo, J. Tyler, 06/08/07; 

D328640). The calculated MRDB for poultry was approximately 0.058 ppm and consisted of 

70% oat grain (dietary burden = 0.056 ppm), 10% wheat milled byproducts (dietary burden = 

0.002 ppm), 5% barley, and 10% untreated. Based on these results, the aforementioned 

tolerances were established.

The only poultry feed item associated with the subject petition is sorghum grain. HED 

recalculated the MRDB for poultry to include this new use (see Table 4). The results of a 

poultry feeding study for pyrasulfotole have been submitted and reviewed by HED (Memo, J. 

Tyler, 6/8/07; D333412). The results of the study are inadequate to determine the need for 

poultry tolerances as only residues of pyrasulfotole-benzoic acid were measured in the study. 

However, because the poultry metabolism studies were conducted for 14 days, the results of the 

these studies can be used to determine the need for a new poultry feeding study and/or poultry

tolerances. Based on the MRDB of 0.52 ppm for poultry, the phenyl-labeled (8.6 ppm) and 

pyrazole-labeled (10.5 ppm) poultry metabolism studies were conducted at 16x and 20x the 

MRDB for poultry, respectively.

In the phenyl-labeled study, total residues of pyrasulfotole and pyrasulfotole-desmethyl were 

0.037 ppm in muscle, 0.065 ppm in fat, and 1.557 ppm in liver. Residues of pyrasulfotole and 

pyrasulfotole-desmethyl at a 1x feeding level would be 0.0023 ppm in muscle, 0.0064 ppm in 

fat, and 0.097 ppm in liver. In the pyrazole-labeled study, total residues of pyrasulfotole and 

pyrasulfotole-desmethyl were 0.018 ppm in muscle, 0.014 ppm in fat, and 1.277 ppm in liver. 

Residues of pyrasulfotole and pyrasulfotole-desmethyl at a 1x feeding level would be 0.00090

ppm in muscle, 0.00070 ppm in fat, and 0.064 ppm in liver. In both radiolabeled studies, as the 

total extractable residues in eggs were < 0.01 ppm; the samples were not analyzed further for 

identification purposes. Based on the results of the poultry metabolism study, there is no 

reasonable expectation of finding quantifiable residues of pyrasulfotole and pyrasulfotoledesmethyl in eggs and poultry muscle and fat. Thus, the established tolerances of 0.02 ppm for 
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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residues of pyrasulfotole and pyrasulfotole-desmethyl in fat, meat, and meat byproducts of 

poultry are adequate. There is reasonable expectation of residues of pyrasulfotole and 

pyrasulfotole-desmethyl in poultry meat byproducts. Therefore, a tolerance of 0.20 ppm for 

residues of pyrasulfotole and pyrasulfotole desmethyl in poultry byproducts is necessary. A 

revised Section F should be submitted to include the above tolerances and correct tolerance 

expression.

860.1500 Crop Field Trials

47815001.der.doc (grass grown for seed); Memo, T. Goodlow, 8/17/10, D380769

47815002.der.doc (grain sorghum) ; Memo, T. Goodlow, 8/17/10, D380769

Grain Sorghum

Table 6. Summary of Residue Data from Crop Field Trials with Pyrasulfotole.

Matrix Total Applic. 

Rate (lb a.i./A)

PHI1(days)

Residue Levels2,3 (ppm)

N Min. Max. HAFT4 Median Mean Std. Dev.

Pyrasulfotole

Sorghum Forage

0.077 - 0.080

(~1x)

0 24 1.097 5.741 5.080 2.167 2.286 1.062

5 to 8 24 0.014 0.462 0.454 0.069 0.133 0.145

ECH (32 to 82) 28 <0.01 0.124 0.123 <0.01 0.026 0.034

Sorghum Grain 56 to 60 24 <0.01 0.151 0.143 0.028 0.041 0.037

Sorghum Stover 56 to 60 24 <0.01 0.035 0.030 0.011 0.015 0.007

Pyrasulfotole-desmethyl

Sorghum Forage

0.077 - 0.080

(~1x)

0 24 0.029 0.346 0.343 0.137 0.164 0.266

5 to 8 24 0.074 0.499 0.479 0.199 0.231 0.359

ECH (32 to 82) 28 <0.01 0.380 0.371 0.050 0.108 0.236

Sorghum Grain 56 to 60 24 <0.01 0.185 0.180 0.056 0.076 0.058

Sorghum Stover 56 to 60 24 <0.01 0.390 0.351 0.129 0.152 0.098

Total Pyrasulfotole

Sorghum Forage

0.077 - 0.080

(~1x)

0 24 1.184 6.021 5.356 2.419 2.449 1.10

5 to 8 24 0.097 0.902 0.881 0.300 0.364 0.241

ECH (32 to 82) 28 <0.02 0.504 0.494 0.043 0.135 0.160

Sorghum Grain 56 to 60 24 <0.02 0.325 0.322 0.089 0.117 0.092

Sorghum Stover 56 to 60 24 <0.02 0.420 0.383 0.142 0.166 0.103

1 ECH = earliest commercial harvest

2 LLMV = 0.01 ppm for each analyte. LOD for pyrasulfotole = 0.0009 ppm for forage, 0.0019 ppm for grain, 0.0033 ppm for 

stover. LOD for pyrasulfotole-desmethyl = 0.0011 ppm for forage, 0.0025 ppm for grain, and 0.0014 ppm for stover. Residues 

in parentheses are between the LOD and LLMV.

3 Total (ppm) = sum of pyrasulfotole (ppm) and pyrasulfotole-desmethyl (ppm). LLMV (0.01 ppm) was used when values were 

<LLMV.

4HAFT = highest-average field trial. 

Bayer CropScience has submitted field trial data for the product HuskieTM Herbicide on grain 

sorghum. Twelve trials were conducted in the United States during the 2008 growing season. 

The trials encompassed NAFTA Growing Zones 2 (1 trial in GA), 4 (1 trial in MS), 5 (1 trial 

each in IN, IA, OH, MN), 6 (1 trial each in OK, TX), 7 (1 trial in ND), and 8 (l trial each in CO, 

OK, TX). Each site consisted of one control plot and two treatment plots, with one treatment 

plot for sampling forage and one for sampling grain and stover. The treatment plots each 

received two applications of the formulated product at a target rate of 0.039 lb pyrasulfotole/A/

application (1x the maximum proposed single application rate). Actual total application rates 
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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ranged from 0.077 to 0.080 lb ai/A/season (1x the maximum proposed seasonal rate). The 

retreatment interval (RTI) ranged from 11 to 16 days and the spray volumes ranged from 12 to 

20 gal/A. An adjuvant was not used in the spray applications. Sorghum forage samples were 

collected at target PHIs of 0 and 7 days and also at earliest commercial harvest (ECH) (BBCH 

81, beginning of ripening, to BBCH 87, hard dough), which corresponded to PHIs of 32 to 82 

days. Sorghum grain and stover samples were collected at a target PHI of 60 days. A residue 

decline trial was also conducted at one site, in which forage samples were collected at PHIs of 0, 

1, 3, 7, 10, and 14 days with additional samples collected at five intervals before, at, and after 

earliest commercial harvest (ECH-14, ECH-7, ECH, ECH+7, and ECH+14 days; actual PHIs 

were 18, 25, 32, 39, and 46 days). Grain and stover samples were collected at five intervals 

corresponding to target PHIs of 47, 53, 60, 67, and 74 days.

After two applications of HuskieTM Herbicide to grain sorghum at a total rate of 0.077 to 0.080 lb 

ai/A (~1x the maximum proposed seasonal rate) for pyrasulfotole, residues of total pyrasulfotole 

(sum of pyrasulfotole and pyrasulfotole-desmethyl) in the forage samples ranged from 1.18 ppm

to 6.02 ppm at a PHI of 0 days, from 0.097 ppm to 0.902 ppm at a PHI of 5 to 8 days, and from 

<LLMV (0.02 ppm) to 0.504 ppm at ECH (PHI of 32 to 82 days). Residues in grain and stover 

samples collected at a PHI of 56 to 60 days from plots treated at a total rate of 0.077 to 0.080 lb 

ai/A ranged from below the LLMV (0.02 ppm) to 0.325 ppm and from <0.02 to 0.420 ppm, 

respectively.

 

Residue decline data showed that residues of pyrasulfotole, pyrasulfotole-desmethyl decreased 

with time in/on grain sorghum early forage. The residues also generally decreased with time 

in/on sorghum forage collected around earliest commercial harvest (ECH -14 day to ECH +14 

day), however, a spike in residues was observed at the ECH -7 day interval. In/on sorghum 

stover, the residues increased with time. In/on sorghum grain, residues of pyrasulfotole and 

pyrasulfotole-desmethyl decreased with time.

HED Conclusions: The submitted grain sorghum residue data are classified as scientifically 

acceptable for determination of the magnitude of residue of pyrasulfotole and pyrasulfotoledesmethyl in grain sorghum. As the number and geographical representation of the trials are the 

same as the number and geographical locations recommended in OPPTS Guideline 860.1500, the 

residue data are adequate to support the proposed uses.

The submitted field trial data reflect the use of HuskieTM Herbicide on grain sorghum. In the 

trials, two applications of HuskieTM Herbicide were applied to each treatment plot at a total 

seasonal rate of 0.078 lb pyrasulfotole/A/season (1x the proposed rate). Forage samples were 

collected at a target 0- and 7- day PHIs, as well as at ECH (PHI of 32 to 82 days). Grain and 

stover samples were collected at a target 60-day PHI. A residue decline trial was also conducted 

at one site, in which forage samples were collected at PHIs of 0, 3, 7, 10, and 14 days with 

additional samples collected at five intervals of ECH-14, ECH-7, ECH, ECH+7, and ECH+14 

days (actual PHIs were 18, 25, 32, 39, and 46 days). Grain and stover samples were collected at 

five intervals corresponding to target PHIs of 47, 53, 60, 67, and 74 days. Based on concurrent 

recoveries, acceptable analytical methods were used. Adequate storage stability data are 

available; however, residues of pyrasulfotole-desmethyl were found to decline in wheat forage 

and hay at approximately 0.12% per day. Therefore, pyrasulfotole-desmethyl residue values in 

grain sorghum forage samples were corrected for 46.3% decline based on wheat forage data and 

pyrasulfotole-desmethyl residue values in grain sorghum stover were corrected for 46.5% decline 

based on wheat hay data. 
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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With the use pattern in this study, total residues of pyrasulfotole in/on grain sorghum forage are 

not expected to exceed 6.02 ppm (0-day PHI), 0.902 ppm (7-day PHI), or 0.504 ppm (ECH). 

In/on sorghum grain and stover (60-day PHI), total residues of pyrasulfotole is not expected to 

exceed 0.325 ppm or 0.420 ppm, respectively. Using the NAFTA MRL/Tolerance 

Harmonization Workgroup methodology for forage (7-day PHI), grain, and stover, the available 

grain sorghum crop field trial data indicate that the appropriate tolerances for residues of 

pyrasulfotole and pyrasulfotole-desmethyl in/on grain sorghum grain commodities are 1.5 ppm 

for sorghum, grain, forage; 0.70 ppm for sorghum, grain, grain; and 0.80 ppm for sorghum, 

grain, stover (see Section 860.1550 Proposed Tolerances). Section F of the petition should be 

revised to include the aforementioned HED-recommended tolerances and the correct 

commodity definitions for grain sorghum RACs.

Grass Grown for Seed

Table 7. Summary of Residue Data from Crop Field Trials with Pyrasulfotole.

Matrix Total Applic. Rate

(lb a.i./A)

PHI 

(days)

Residue Levels1,2 (ppm)

N Min. Max. HAFT3 Median Mean Std. Dev.

Pyrasulfotole

Grass Forage 0.076 - 0.091

(~1x)

0 24 0.055 6.51 6.39 1.83 2.54 2.11

7-11 26 <0.01 6.32 6.21 0.079 1.33 2.09

Grass Hay 0.077 - 0.080

(~1x)

28-31 24 <0.01 1.71 1.69 0.0183 0.202 0.472

Pyrasulfotole-desmethyl

Grass Forage 0.076 - 0.091

(~1x)

0 24 0.045 0.631 0.619 0.182 0.234 0.181

7-11 26 0.041 0.544 0.512 0.205 0.234 0.146

Grass Hay 0.077 - 0.080

(~1x)

28-31 24 <0.01 0.607 0.574 0.112 0.186 0.172

Total Pyrasulfotole

Grass Forage 0.076 - 0.091

(~1x)

0 24 0.132 6.77 6.75 2.49 3.14 2.20

7-11 26 0.062 6.52 6.40 0.317 1.56 2.09

Grass Hay 0.077 - 0.080

(~1x)

28-31 24 <0.02 2.31 2.27 0.157 0.390 0.611

1 LLMV = 0.01 ppm for each analyte. LOD for pyrasulfotole = 0.00353 ppm for forage and 0.00162 for hay. LOD for 

pyrasulfotole-desmethyl = 0.00521 ppm for forage and 0.00132 ppm for hay. Residues in parentheses are between the LOD and 

LLMV.

2 Total (ppm) = sum of pyrasulfotole (ppm) and pyrasulfotole-desmethyl (ppm). LLMV (0.05 ppm) was used when values were 

<LLMV.

3HAFT = highest-average field trial.

Bayer CropScience has submitted field trial data for the product HuskieTM Herbicide on grass 

grown for seed (Bermuda, bluegrass, and fescue). Twelve trials were conducted in the United 

States and Canada during the 2008 growing season. The trials encompassed NAFTA Growing 

Zones 1 (1 trial in Atlantic Provinces, Canada), 2 (1 trial in GA), 3 (1 trial in FL), 4 (1 trial in 

AR), 5 (1 trial in WI; 1 trial in NE), 9 (1 trial in ID), 10 (1 trial in CA), 11 (1 trial in ID; 1 trial in 

WA), and 12 (1 trial in British Columbia, Canada; 1 trial in OR). Each site consisted of one 

control plot and two treatment plots, with one treatment plot for sampling forage and one for 

sampling hay. The treatment plots each received two broadcast foliar applications of the 

formulated product at a target rate of 0.039 lb pyrasulfotole/A/application (~1x the maximum 

proposed single application rate). Actual total application rates ranged from 0.076 to 0.091 lb 

ai/A/season (~1x the maximum proposed seasonal application rate) with a 27- to 30-day RTI. 
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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Spray volumes ranged from 10 to 24 gal/A. An adjuvant was not used in the spray applications. 

Grass forage samples were collected at target PHI of 0 days and 7 days. Grass hay samples were 

collected at a target PHI of 30 days. A residue decline trial was also conducted at one site, in 

which forage samples were collected at PHIs of 0, 1, 3, 7, 10, and 14 days and hay samples were 

collected at PHIs of 20, 25, 30, 36, and 40 days.

After two applications of HuskieTM Herbicide to grass at a total rate of 0.076 to 0.091 lb ai/A (~1x 

the maximum proposed seasonal rate), residues of pyrasulfotole in/on the grass forage samples 

ranged from 0.055 ppm to 6.51 ppm at a PHI of 0 days and from below the LLMV (<0.01 ppm) 

to 6.32 ppm at a PHI of 7 to 11 days. Residues of pyrasulfotole-desmethyl in/on the grass forage 

samples ranged from 0.045 ppm to 0.631 ppm at a PHI of 0 days and from 0.041 ppm to 0.544 

ppm at a PHI of 7 to 11 days. Total pyrasulfotole residues in/on the forage samples ranged from 

0.132 ppm to 6.77 ppm at a PHI of 0 days and from 0.062 ppm to 6.52 ppm at a PHI of 7 to 11 

days. Pyrasulfotole residues in/on grass hay samples, collected at a PHI of 28 to 31 days from 

plots treated with HuskieTM Herbicide a total rate of 0.076 - 0.091 lb ai/A, ranged from below the 

LLMV to 1.71 ppm. Residues of pyrasulfotole-desmethyl in/on the grass hay samples ranged 

from below the LLMV to 0.607 ppm and total pyrasulfotole residues ranged from below the 

LLMV (<0.02 ppm) to 2.31 ppm. 

Residue decline data showed that residues of pyrasulfotole and metabolites decreased with time 

in grass forage and hay. A slight increase in pyrasulfotole residues was observed in grass hay

between the 30 and 35 day PHI interval.

HED Conclusions: The submitted grass residue data are classified as scientifically acceptable 

for determination of the magnitude of residue of pyrasulfotole and pyrasulfotole-desmethyl in 

grass grown for seed.

The submitted field trial data reflect the use of HuskieTM Herbicide on grass grown for seed. In 

the trials, two applications of HuskieTM Herbicide was applied to each treatment plot at a total 

seasonal rate of 0.076 to 0.091 lb ai/A. Forage samples were collected at a target 0- and 7- day

PHI and hay samples were collected at a target 30-day PHI. Decline trials were also conducted 

in which sample collection occurred at PHIs of 0, 1, 3, 7, 10 and 14 days for forage and 20, 25, 

30, 35, and 40 days for hay. Based on concurrent recoveries, acceptable analytical methods were 

used. Storage stability data from grass, wheat, and/or barley demonstrate that residues of 

pyrasulfotole is stable in grass forage and hay under the storage conditions used in this study; 

however, residues of pyrasulfotole-desmethyl were found to decline in wheat forage and hay at 

approximately 0.12% per day. Therefore, pyrasulfotole-desmethyl residue values in grass forage 

samples were corrected for 46.3% decline based on wheat forage data and pyrasulfotoledesmethyl residue values in grass hay samples were corrected for 46.5% decline based on wheat 

hay data.

With the use pattern in this study, total residues of pyrasulfotole, are not expected to exceed 6.73

ppm (0-day PHI) or 6.52 ppm (7-day PHI) in/on grass forage and 2.31 ppm in grass hay (30-day

PHI). Using the NAFTA MRL/Tolerance Harmonization Workgroup methodology for grass 

forage (7-day PHI) and hay, the available grass crop field trial data indicate that the appropriate 

tolerances for residues of pyrasulfotole and pyrasulfotole-desmethyl in/on are 25 ppm for grass, 

forage; and 3.5 ppm for grass, hay (see Section 860.1550 Proposed Tolerances). Section F of 

the petition should be revised to include the aforementioned HED-recommended 

tolerances.
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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In addition, the proposed label does not specify application equipment or a minimum spray

volume for application to grass grown for seed. The submitted data support ground foliar 

applications made in spray volumes of 10-24 gal/A. A revised label should be submitted to 

include these use directions.

860.1520 Processed Food and Feed

As there are no processed commodities associated with the proposed uses, processing studies are 

not required.

860.1650 Submittal of Analytical Reference Standards

Analytical reference standards for pyrasulfotole have been received by the EPA National 

Pesticide Standard Repository for distribution to State and Federal regulatory labs (personal 

communication between J. Tyler and T. Cole, 9/15/10). However, the Repository has not 

received reference standard for the desmethyl metabolite and labeled internal standards. These 

standards should be sent to the Analytical Chemistry Lab to the attention of either Theresa Cole 

or Dallas Wright at the following address:

USEPA

National Pesticide Standards Repository/Analytical Chemistry Branch/OPP

701 Mapes Road

Fort George G. Meade, MD 20755-5350

The extended zip code must be used or the mail will be returned.

860.1850 and 860.1900 Confined/Field Accumulation in Rotational Crops

No rotational crop data were submitted in conjunction with the proposed uses. According to the 

current guidance, grain sorghum and grass grown for seed are considered to be rotated crops. 

The following rotational crop restrictions are currently on the proposed label:

Wheat, barley, oats, rye and triticale 1 month

Alfalfa*, millet, sorghum (grain), and soybeans 4 months

Canola, canaryseed, chickpeas, corn, dry beans, flax, field peas, green beans, green peas, 

lentils**, mustards, potatoes, safflower, sunflowers, and sugar beets

9 months

All other crops 30 days***

*Thorough tillage prior to planting alfalfa and a minimum of 12 inches of rainfall, overhead, furrow or flood irrigation or any 

combination of these water source totaling 12 inches is required between the time following a HuskieTM Herbicide application and 

the time of alfalfa seeding.

**Lentils: 9 months for all states except 18 months in MN, MT, ND, and SD.

***Where a crop is not specified, conduct a field bioassay as described in “FIELD BIOASSAY” section of proposed label.

Adequate confined and field rotational crop data have been submitted by the petitioner and 

reviewed by HED in conjunction with PP#6F7509 (Memo, J. Tyler, 6/8/07, D366490). The 
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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results of the submitted confined and limited field rotational crop studies together are adequate to 

determine appropriate PBIs for rotational crops. In the confined rotational crop study, following 

application of either phenyl- or pyrazole-labeled pyrasulfotole, the TRR in the 122-days after 

treatment (DAT) Swiss chard, turnip tops, and turnip roots were <0.01 (<LOQ). In the limited 

field rotational crop study, maximum residue levels of pyrasulfotole and pyrasulfotole-desmethyl

were <LOD in all corn and soybean RACs at PBIs of 114-123 days. Maximum residues levels 

for pyrasulfotole-benzoic acid were 0.0018 ppm in corn forage, 0.0027 ppm in soybean forage, 

0.0126 ppm in soybean hay and <LOD in corn grain, corn stover and soybean seed. However, it 

was determined that residues of pyrasulfotole-benzoic acid are not of concern for both tolerance 

and risk assessment purposes (Memo, J. Tyler et al., 06/08/07; D328640).

In addition, HED approved a requested to revise the Crop Rotation Guidelines on the currently 

approved HuskieTM Herbicide (EPA Reg. No. 264-1023) label as follows: 1) an increased PBI 

from 7 days to 1 month for wheat, barley, oats, rye, and triticale; 2) an addition of green beans 

and green peas to the 9-month PBI; and 3) a decreased PBI for alfalfa from 9 months to 4 

months. Therefore, the submitted confined and limited field trial data support the proposed 

PBIs.

860.1550 Proposed Tolerances

A summary of the recommended tolerances and the correct commodity definitions for the 

proposed uses are listed in Table 8. 

The available crop field trial data on grain sorghum and grass grown for seed are adequate to 

support the proposed uses of pyrasulfotole. For purposes of determining appropriate tolerance 

levels for the proposed uses, individual pyrasulfotole and pyrasulfotole-desmethyl residues were 

summed to yield a total residue value. Appropriate tolerances where determined using the 

methodology formulated by the NAFTA MRL/Tolerance Harmonization Workgroup for 

calculating statistically-based pesticide tolerances for plant commodities based on field trial 

residue data.

Using the 0.67x data from the adequate cattle feeding study and a calculated MRDB of 45 ppm 

for pyrasulfotole and pyrasulfotole-desmethyl residues in dairy cattle diets, estimated 

pyrasulfotole and pyrasulfotole-desmethyl residues in ruminants at a 1x dose level are 0.0200 

ppm in milk; 0.00127 ppm in milk fat; 0.0213 ppm in fat; 0.00582 ppm in muscle; 2.89 ppm in 

liver; and 0.618 ppm in kidney. Based on the quantifiable residues, tolerances should be 

established for residues of pyrasulfotole and pyrasulfotole-desmethyl in/on milk at 0.03 ppm; fat 

of cattle, goat, horse and sheep at 0.03 ppm; liver of cattle, goat, horse, and sheep at 3.0 ppm; 

and meat byproducts, except liver, of cattle, goat, horse, and sheep at 0.70 ppm. Although, there 

is no reasonable expectation of finding quantifiable residues of pyrasulfotole and pyrasulfotoledesmethyl in muscle of cattle, goat, horse and sheep, the current tolerances for these 

commodities (established in order to harmonize with PMRA) are adequate to support the 

proposed uses on grain sorghum and grass grown for seed.

Using data from the adequate cattle feeding study and a calculated MRDB of 0.56 ppm 

pyrasulfotole and pyrasulfotole-desmethyl in hogs, the estimated pyrasulfotole and pyrasulfotoledesmethyl residues in hogs were 0.00019 ppm in muscle, 0.042 ppm in kidney, 0.23 ppm in 

liver, and 0.0012 ppm in fat. There is no reasonable expectation of finding quantifiable residues 
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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of pyrasulfotole and pyrasulfotole-desmethyl in muscle and fat; however, the current tolerances 

of 0.02 ppm (established in order to harmonize with PMRA) are adequate to support the 

proposed uses on grain sorghum and grass grown for seed. There is reasonable expectation of 

residues of pyrasulfotole and pyrasulfotole-desmethyl in hog liver and kidney. Therefore, the 

following tolerances for residues of pyrasulfotole and pyrasulfotole desmethyl are necessary: 

hog, meat byproducts, except liver at 0.05 ppm; and hog, liver at 0.30 ppm.

Using the data from the poultry metabolism studies and a calculated MRDB of 0.52 ppm for 

poultry, the maximum estimated pyrasulfotole and pyrasulfotole-desmethyl residues in poultry

were 0.0023 ppm in muscle, 0.0070 ppm in fat, and 0.097 ppm in liver. As the total extractable 

residues in eggs were <0.01 ppm; the samples were not analyzed further for identification 

purposes. Based on the results of the poultry metabolism study, there is no reasonable 

expectation of finding quantifiable residues of pyrasulfotole and pyrasulfotole-desmethyl in eggs 

and poultry muscle and fat; however, the current tolerances of 0.02 ppm (established in order to 

harmonize with PMRA) are adequate to support the proposed uses on grain sorghum and grass 

grown for seed. There is reasonable expectation of residues of pyrasulfotole and pyrasulfotoledesmethyl in poultry meat byproducts. Therefore, a tolerance of 0.20 ppm for residues of 

pyrasulfotole and pyrasulfotole desmethyl in poultry byproducts is necessary.

The residue chemistry database supports the establishment of the permanent tolerances for the 

combined residues of pyrasulfotole and pyrasulfotole-desmethyl in/on the RACs and livestock 

commodities listed in Table 8. Section F should be revised to include these recommended 

tolerances as well as the correct tolerance expression for livestock commodities.

Table 8. Tolerance Summary for Pyrasulfotole.

Commodity Current 

Tolerance (ppm)

Proposed 

Tolerance (ppm)

Recommended 

Tolerance (ppm)

Comments

(correct commodity definition)

Sorghum, grain - 0.8 0.70 Sorghum, grain, grain

Sorghum, forage - 1.2 1.5 Sorghum, grain, forage

Sorghum, stover - 0.35 0.80 Sorghum, grain, stover

Grass, forage - 10 25

Grass, hay - 2.5 3.5

Milk* 0.01 0.01 0.03

Cattle, meat 0.02 0.04 see current tolerance

Cattle, fat* 0.02 0.04 0.03

Cattle, meat byproducts* 0.06 2 0.70 Cattle, meat byproducts, except liver

Cattle, liver* 0.35 8 3.0

Goat, meat 0.02 0.04 see current tolerance

Goat, fat* 0.02 0.04 0.03

Goat, meat byproducts* 0.06 2 0.70 Goat, meat byproducts, except liver

Goat, liver* 0.35 8 3.0

Hog, meat 0.02 0.04 see current tolerance

Hog, fat 0.02 0.04 see current tolerance

Hog, meat byproducts* 0.06 2 0.05 Hog, meat byproducts, except liver

Hog, liver* - 8 0.30

Sheep, meat 0.02 0.04 see current tolerance

Sheep, fat* 0.02 0.04 0.03

Sheep, meat byproducts* 0.06 2 0.70 Sheep, meat byproducts, except liver
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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Table 8. Tolerance Summary for Pyrasulfotole.

Commodity Current 

Tolerance (ppm)

Proposed 

Tolerance (ppm)

Recommended 

Tolerance (ppm)

Comments

(correct commodity definition)

Sheep, liver* 0.35 8 3.0

Horse, meat 0.02 0.04 see current tolerance

Horse, fat* 0.02 0.04 0.03

Horse, meat byproducts* 0.06 2 0.70 Horse, meat byproducts, except liver

Horse, liver* 0.35 8 3.0

Poultry, meat 0.02 - see current tolerance

Poultry, fat* 0.02 - 0.02

Poultry, meat byproducts* 0.02 - 0.20

Eggs 0.02 - see current tolerance

* Livestock commodities with tolerances that are not harmonized with PMRA.

The International Residue Limit Status (IRLS) Sheet is attached as Attachment 1. There are no 

established Mexican or Codex MRLs for the proposed uses. There are Canadian MRLs 

established for livestock commodities. However, due to the recommended tolerances on the 

proposed uses, there was an increase in MRDB for livestock commodities. This resulted in the 

need for an increase in tolerances for several livestock commodities (see commodities with 

asterisk in Table 8). Therefore, harmonization is not possible at this time.

Attachments

Attachment 1: IRLS Sheet.

Attachment 2: Inputs for calculating statistically-based pesticide tolerances.

cc: J. Tyler (RAB1)

RDI: RAB1 Chemists (9/29/10), G. Kramer (9/27/10)

J. Tyler: S-10943: Potomac Yard: (703) 305-5564: RAB1
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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Attachment 1. IRLS Sheet.

International Residue Limits 

Pyrasulfotole (000692; 15-SEP-2010)

Summary of US and International Tolerances and Maximum Residue Limits 

Residue Definition:

US Canada Mexico2 Codex

40 CFR 180.631:

Plant/Livestock: pyrasulfotole and pyrasulfotoledesmethyl, (5-hydroxy-1,3-dimethyl-1H-pyrazol-4-

yl)[2-(methylsulfonyl)-4-

(trifluoromethyl)phenyl]methanone, and its 

metabolite, 5-hydroxy-3-methyl-1H-pyrazol-4-yl) [2-

methylsulfornyl)-4-

(trifluoromethyl)phenyl]methanone

(5-hydroxy-1,3-dimethyl-1H-pyrazol-4-

yl)[2-(methylsulfonyl)-4-

(trifluoromethyl)phenyl]methanone, 

including the metabolite (5-hydroxy-3-

methyl-1H-pyrazol-4-yl)[2-

(methylsulfonyl)-4-

(trifluoromethyl)phenyl]methanone

None

Commodity1 Tolerance (ppm) /Maximum Residue Limit (mg/kg)

US Canada Mexico2 Codex

Sorghum, grain 0.7

Sorghum, forage 1.5

Sorghum, stover 0.8

Grass, forage 10

Grass, hay 3.5

Milk 0.1 0.01

Cattle, meat 0.02 0.02

Cattle, fat 0.02 0.02

Cattle, meat byproducts, except liver 1.0 0.06

Cattle, liver 4.0 0.35

Goat, meat 0.02 0.02

Goat, fat 0.02 0.02

Goat, meat byproducts, except liver 1.0 0.06

Goat, liver 4.0 0.35

Hog, meat 0.02 0.02

Hog, fat 0.02 0.02

Hog, meat byproducts, except liver 0.05 Meat byproducts of hogs 0.02

Hog, liver 0.30

Sheep, meat 0.02 0.02

Sheep, fat 0.02 0.02

Sheep, meat byproducts, except liver 1.0 0.06

Sheep, liver 4.0 0.35

Horse, meat 0.02 0.02

Horse, fat 0.02 0.02

Horse, meat byproducts, except liver 1.0 0.06

Horse, liver 4.0 0.35

Poultry, meat 0.02 0.02

Poultry, fat 0.02 0.02

Poultry, meat byproducts 0.20 0.02

Eggs 0.02 0.02

Completed: M. Negussie; 09/16/2010

1

Includes only commodities of interest for this action. Tolerance values should be the HED recommendations and not those proposed by the 

applicant.

2 Mexico adopts US tolerances and/or Codex MRLs for its export purposes.
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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Attachment 2. Inputs for calculating statistically-based pesticide tolerances.

Grass Forage – 7-day PHI

Regulator: EPA

Chemical: Pyrasulfatole

Crop: Grass Forage

PHI: 7 days

App. Rate: 0.076 - 0.091 lb ai/A

Submitter:

Residues LN(Residues)

Zscores

0.264 -1.33 -0.53

0.279 -1.28 -0.41

5.62 1.73 1.19

4.635 1.53 0.98

1.27 0.24 0.29

1.204 0.19 0.17

0.147 -1.92 -0.98

0.133 -2.02 -1.19

6.278 1.84 1.45

6.523 1.88 1.91

3.571 1.27 0.67

3.829 1.34 0.81

1.587 0.46 0.41

1.686 0.52 0.53

0.259 -1.35 -0.67

0.193 -1.65 -0.81

0.062 -2.78 -1.91

0.064 -2.75 -1.45

0.311 -1.17 -0.17

0.319 -1.14 0.06

0.304 -1.19 -0.29

0.315 -1.16 -0.06

Lognormal Probability Plot

0.1 1 2 5 10 20 30 50 70 80 90 95 98 99 99.9

7.0000

3.5000

1.7500

0.8750

0.4375

0.2188

0.1094

0.0547

y = 1.5259x - 0.3967

R

2

 = 0.9279

Percentiles

Concentrations

EPA Pyrasulfatole Grass Forage 7 days 0.076 - 0.091 lb ai/A
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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Regulator: EPA

Chemical: Pyrasulfatole

Crop: Grass Forage

PHI: 7 days

App. Rate: 0.076 - 0.091 lb ai/A

Submitter:

n: 22

min: 0.06

max: 6.52

median: 0.32

average: 1.77

95th Percentile 99th Percentile 99.9th Percentile

6.0 7.0 9.0

(7.0) (9.0) (--)

9.0 25 80

(25) (95) (--)

8.0

9.0

1.7

0.9279

p-value > 0.05 : Do not reject lognormality assumption

Approximate 

Shapiro-Francia

Normality Test 

EU Method I

Normal

UCLMedian95th

95/99 Rule

EU Method II

Distribution-Free

Mean+3SD

Grass Hay

Regulator: EPA

Chemical: Pyrasulfatole

Crop: Grass Hay

PHI: 29-31 days

App. Rate: 0.077 - 0.080 lb ai/A

Submitter:

Residues LN(Residues)

Zscores

0.148 -1.91 -0.05

0.166 -1.80 0.05

0.375 -0.98 0.60

0.348 -1.06 0.48

2.315 0.84 1.95

2.217 0.80 1.50

0.141 -1.96 -0.16

0.126 -2.07 -0.37

0.096 -2.34 -0.48

0.067 -2.70 -0.73

0.131 -2.03 -0.26

0.253 -1.37 0.37

0.02 -3.91 -1.95

0.032 -3.44 -1.50

0.068 -2.69 -0.60

0.065 -2.73 -0.88

0.548 -0.60 1.04

0.864 -0.15 1.24

0.045 -3.10 -1.24

0.055 -2.90 -1.04

0.416 -0.88 0.73

0.437 -0.83 0.88

0.207 -1.58 0.16

0.212 -1.55 0.26
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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Lognormal Probability Plot

0.1 1 2 5 10 20 30 50 70 80 90 95 98 99 99.9

3.0000

1.5000

0.7500

0.3750

0.1875

0.0938

0.0469

0.0234

0.0117

y = 1.2413x - 1.7061

R

2

 = 0.9771

Percentiles

Concentrations

EPA Pyrasulfatole Grass Hay 29-31 days 0.077 - 0.080 lb ai/A

Regulator: EPA

Chemical: Pyrasulfatole

Crop: Grass Hay

PHI: 29-31 days

App. Rate: 0.077 - 0.080 lb ai/A

Submitter:

n: 24

min: 0.02

max: 2.32

median: 0.16

average: 0.39

95th Percentile 99th Percentile 99.9th Percentile

1.4 1.9 2.5

(1.9) (2.5) (--)

1.4 3.5 8.0

(3.5) (9.0) (--)

0.90

2.5

0.90

0.9771

p-value > 0.05 : Do not reject lognormality assumption

Approximate 

Shapiro-Francia 

Normality Test 

EU Method I

Normal

UCLMedian95th

95/99 Rule

EU Method II

Distribution-Free

Mean+3SD

Sorghum Forage

Regulator: EPA

Chemical: Pyrasulfotole

Crop:

Sorghum 

Forage

PHI: 5-7 days

App. Rate: 0.077 - 0.080 lb ai/A

Submitter:

Residues

LN(Resi

dues) Z-scores

0.097 -2.33 -1.95

0.11 -2.21 -1.50

0.119 -2.13 -1.04

0.118 -2.14 -1.24

0.554 -0.59 0.73

0.474 -0.75 0.48

0.159 -1.84 -0.73

0.127 -2.06 -0.88

0.616 -0.48 0.88

0.549 -0.60 0.60

0.349 -1.05 0.16

0.372 -0.99 0.37

0.229 -1.47 -0.37

0.311 -1.17 0.05

0.86 -0.15 1.50

0.902 -0.10 1.95

0.288 -1.24 -0.05

0.363 -1.01 0.26

0.24 -1.43 -0.16

0.237 -1.44 -0.26

0.637 -0.45 1.04
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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0.674 -0.39 1.24

0.17 -1.77 -0.60

0.173 -1.75 -0.48

Lognormal Probability Plot

0.1 1 2 5 10 20 30 50 70 80 90 95 98 99 99.9

1.0000

0.5000

0.2500

0.1250

0.0625

y = 0.7037x - 1.2318

R

2

 = 0.9652

Percentiles

Concentrations

EPA Pyrasulfatole Sorghum Forage 5-7 days 0.077 - 0.080 lb ai/A

Regulator: EPA

Chemical: Pyrasulfatole

Crop: Sorghum Forage

PHI: 5-7 days

App. Rate: 0.077 - 0.080 lb ai/A

Submitter:

n: 24

min: 0.10

max: 0.90

median: 0.30

average: 0.36

95th Percentile 99th Percentile 99.9th Percentile

0.80 1.0 1.2

(1.0) (1.2) (--)

1.0 1.5 2.5

(1.5) (3.0) (--)

1.2

1.1

1.6

0.9652

p-value > 0.05 : Do not reject lognormality assumption

Approximate 

Shapiro-Francia 

Normality Test 

EU Method I

Normal

UCLMedian95th

95/99 Rule

EU Method II

Distribution-Free

Mean+3SD

Sorghum Grain

Regulator: EPA

Chemical: Pyrasulfotole

Crop: Sorghum Grain

PHI: 56-60 days

App. Rate: 0.077 - 0.080 lb ai/A

Submitter:

Residues LN(Residues)

Zscores

0.02 -3.91 -1.95

0.02 -3.91 -1.50

0.074 -2.60 -0.05

0.07 -2.66 -0.16

0.191 -1.66 0.73

0.234 -1.45 1.24

0.104 -2.26 0.05

0.116 -2.15 0.16

0.0621 -2.78 -0.26

0.06 -2.81 -0.37

0.325 -1.12 1.95

0.32 -1.14 1.50

0.218 -1.52 1.04

0.194 -1.64 0.88

0.02 -3.91 -1.24

0.02 -3.91 -1.04

0.0359 -3.33 -0.73

0.034 -3.38 -0.88
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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0.124 -2.09 0.37

0.118 -2.14 0.26

0.177 -1.73 0.60

0.165 -1.80 0.48

0.0597 -2.82 -0.48

0.0532 -2.93 -0.60

Lognormal Probability Plot

0.1 1 2 5 10 20 30 50 70 80 90 95 98 99 99.9

1.0000

0.5000

0.2500

0.1250

0.0625

0.0313

0.0156

y = 0.9096x - 2.4864

R

2

 = 0.9516

Percentiles

Concentrations

EPA Pyrasulfatole Sorghum Grain 56-60 days 0.077 - 0.080 lb ai/A

Regulator: EPA

Chemical: Pyrasulfatole

Crop: Sorghum Grain

PHI: 56-60 days

App. Rate: 0.077 - 0.080 lb ai/A

Submitter:

n: 24

min: 0.02

max: 0.33

median: 0.09

average: 0.12

95th Percentile 99th Percentile 99.9th Percentile

0.30 0.35 0.45

(0.35) (0.45) (--)

0.40 0.70 1.4

(0.70) (1.5) (--)

0.40

0.40

0.50

0.9516

p-value > 0.05 : Do not reject lognormality assumption

Approximate 

Shapiro-Francia 

Normality Test 

EU Method I

Normal

UCLMedian95th

95/99 Rule

EU Method II

Distribution-Free

Mean+3SD

Sorghum Stover

Regulator: EPA

Chemical: Pyrasulfatole

Crop:

Sorghum 

Stover

PHI: 56-60 days

App. Rate: 0.077 - 0.080 lb ai/A

Submitter:

Residues LN(Residues)

Zscores

0.066 -2.72 -0.73

0.072 -2.63 -0.60

0.136 -2.00 -0.37

0.141 -1.96 -0.05

0.148 -1.91 0.16

0.108 -2.23 -0.48

0.269 -1.31 0.88

0.184 -1.69 0.26

0.28 -1.27 1.04

0.42 -0.87 1.95

0.136 -2.00 -0.26

0.057 -2.86 -1.50

0.137 -1.99 -0.16

0.057 -2.86 -1.24
Pyrasulfotole Summary of Analytical Chemistry and Residue Data DP# 375391

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0.142 -1.95 0.05

0.058 -2.85 -1.04

0.207 -1.58 0.48

0.236 -1.44 0.73

0.02 -3.91 -1.95

0.06 -2.81 -0.88

0.199 -1.61 0.37

0.21 -1.56 0.60

0.346 -1.06 1.50

0.303 -1.19 1.24

Lognormal Probability Plot

0.1 1 2 5 10 20 30 50 70 80 90 95 98 99 99.9

1.0000

0.5000

0.2500

0.1250

0.0625

0.0313

0.0156

y = 0.7318x - 2.0113

R

2

 = 0.9424

Percentiles

Concentrations

EPA Pyrasulfatole Sorghum Stover 56-60 days 0.077 - 0.080 lb ai/A

Regulator: EPA

Chemical: Pyrasulfatole

Crop: Sorghum Stover

PHI: 56-60 days

App. Rate: 0.077 - 0.080 lb ai/A

Submitter:

n: 24

min: 0.02

max: 0.42

median: 0.14

average: 0.17

95th Percentile 99th Percentile 99.9th Percentile

0.35 0.45 0.50

(0.45) (0.50) (--)

0.45 0.80 1.3

(0.80) (1.4) (--)

0.50

0.50

0.80

0.9424

p-value > 0.05 : Do not reject lognormality assumption

Approximate 

Shapiro-Francia 

Normality Test 

EU Method I

Normal

UCLMedian95th

95/99 Rule

EU Method II

Distribution-Free

Mean+3SD