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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF

CHEMICAL SAFETY AND

POLLUTION PREVENTION

MEMORANDUM

Date: August 31, 2010 

SUBJECT: Fluazifop-P-Butyl. Request for the Registration of a Reduced Pre-Harvest Interval for 

Application of the Venture L End-Use Product on Imported Potatoes. Summary of 

Analytical Chemistry and Residue Data.

PC Code: 122809 DP Barcode: 372408 & 380010

Decision No.: 423996 Registration No.: 100-1001

Petition No.: 9E7651 Regulatory Action: New Use Registration

Risk Assessment Type: NA Case No.: 2285

TXR No.: NA CAS No.: 79241-46-6

MRID No.: Summary Table Provided Below 40 CFR: 180.411

FROM: Peter Savoia, Chemist

Risk Assessment Branch V

Health Effects Division (7509P)

THRU: William H. Donovan, Ph.D., Chemist

Risk Assessment Branch V

Health Effects Division (7509P)

TO: Kathryn Montague/Michael Walsh, RM

Herbicide Branch 

Registration Division (7505P)

MRID Summary Table

MRID No. Study Type Comments

47920401 860.1340 (Residue Analytical Method) 47920402.der.doc & 47920403.der.doc

47920402 860.1500 (potato) 47920402.der.doc

47920403 860.1500 (potato) 47920403.der.doc

47920404 860.1500 (reduced PHI for potato) No separate der

47920405 860.1520 (potato) 47920405.der.doc
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

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Prior actions made to develop the fluazifop-P-butyl herbicide active ingredient (ai) have identified a 

number of studies that are required for completing data gaps. In accordance, a number of Data Call-In

(DCI) submissions have been provided by the registrant in order to satisfy these database 

requirements. These studies are as follows:

• Carrot and endive nature of residue studies, test guideline 860.1300. 

• Ruminant and poultry nature of residue studies, test guideline 860.1300. 

• Radiovalidation study made for the tolerance enforcement method proposed for analyzing plants, 

test guideline 860.1340. 

• Method validation study made for the tolerance enforcement method proposed for analyzing 

poultry, eggs and livestock, test guideline 860.1340.

• Cattle and poultry feeding studies, test guideline 860.1480.

• Confined rotational crop study, test guideline 860.1850. 

In all, an assessment of these studies is currently in progress and will be addressed in a separate 

memorandum in due course. Should the results of the studies submitted in response to the registration

DCI impact the conclusions reached in this summation, appropriate changes will be made at that time. 

No further discussion of these in review studies will be included in this memorandum.

Executive Summary

Fluazifop-P-butyl [(R)-2-(4-((5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propanoic acid, butyl 

ester] is a selective herbicide registered for postemergence control of perennial and annual grass 

weeds. It is the resolved isomer (R enantiomer) of fluazifop-butyl [(R,S)-2-(4-((5-(trifluoromethyl)-2-

pyridinyl)oxy)phenoxy) propanoic acid, butyl ester]. After application fluazifop-P-butyl is rapidly

hydrolyzed to fluazifop acid (R enantiomer) where it accumulates in the meristems of grass weeds

working to interrupt lipid synthesis in susceptible plants. Fluazifop-P-butyl end-use products are 

registered in the United States to Syngenta Crop Protection, Inc. under the trade names Fusilade®, 

Fusion®, Oramec®, Tornado®, and Typhoon®. 

This herbicide active ingredient is the resolved isomer (R enantiomer) of fluazifop-butyl (PC code 

122805) which has since been cancelled resulting in only fluazifop-P-butyl to be supported for reregistration. The Residue Chemistry Chapter of the Fluazifop-P-Butyl TRED (referred to herein as 

the Residue Chapter) was issued on August 17, 2005 (DP No. 319907, S. L. Kinard, 08/17/2005). It 

provided the Residue Chemistry Assessments that went into the “Report on FQPA Tolerance 

Reassessment Progress and Interim Risk Management Decisions (TRED) for fluazifop-P-butyl.”

In the current petition, Syngenta Crop Protection, Inc. requests the establishment of a tolerance for the 

residues of fluazifop-P-butyl in/on imported potatoes and its processed commodities:

Potato, tubers........................................................................1.1 ppm

Potato, wet peel....................................................................1.1 ppm

Potato, chips.........................................................................3.0 ppm

Potato, granules/flakes.........................................................5.0 ppm
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

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The end-use products relevant for this petition request are the VENTURE L and Fusilade® MAX(X) 

herbicide Emulsifiable Concentrate (EC) formulations. These end-use products are identical with 

both of them containing approximately 14.0% fluazifop-P-butyl active ingredient (ai) equivalent to 

125 g ai/L. For this action, Syngenta has requested to amend the label of the VENTURE L product by

adding this new use on potatoes. In addition, the registrant is requesting that the application 

instructions also be amended to allow for treatments to be made at the late seasonal timed Pre-Harvest 

Interval (PHI) of 45 days. Treatments of these products are to be made as a single foliar spray

application not to exceed the maximum labeled rate of 250 g ai/ha timed at a PHI of 45 or 90 days. 

Fluazifop-butyl isomers are List B chemicals with parent and fluazifop-acid (free and conjugated) 

regulated for tolerance expression as the residues of concern used to determine misuse (DP No. 

D319907, S. L. Kinard, 08/17/2005). Its registered uses include dry beans, carrot, cotton, endive 

(escarole), macadamia nut, onion, peanut, pecan, soybean, spinach, stone fruit, and sweet potato. It 

also carries tolerances with regional registrations on asparagus, coffee, pepper, and rhubarb along 

with being registered for use on lawns as a weed control application. Tolerances are established 

under 40 CFR §180.411(a)(1) and (c)(1) for residues of fluazifop-butyl, including free and conjugated 

fluazifop, expressed as fluazifop. For fluazifop-P-butyl, including free and conjugated fluazifop (R 

isomer), tolerances are likewise established under 40 CFR §180.411(a)(2) and (c)(2) with residues 

expressed as fluazifop.

The nature of the residue in both plants and livestock cannot yet be described as adequately

understood. For the current action, an acceptable soybean metabolism study is available, and the 

soybean metabolism study will also support the proposed uses on the other crops addressed herein. 

The Metabolism Assessment Review Committee (MARC) concluded that the residues of concern for 

tolerance expression for plants and animals are parent and fluazifop-acid (free and conjugated) since 

they are adequate to determine misuse. The MARC also concluded that the residues of concern in 

plants for risk assessment are parent, fluazifop-acid (free and conjugated), 5-trifluoromethyl-2-

pyridone, and 2-(4-hydroxyphenoxy) propionic acid (free and conjugated). The residues of concern in 

animals for risk assessment are parent and fluazifop-acid (free and conjugated) (DP No. D298939, S.

L. Kinard, 6/22/2004).

There are adequate residue analytical methods listed in PAM II for tolerance enforcement and data 

collection. For the enforcement of tolerances for fluazifop-P-butyl residues of concern, a High

Performance Liquid Chromatography/Ultra-Violet Spectrometry (HPLC/UV) method is available for 

crop commodities. In conjunction, HPLC/UV and Gas Chromatography/Mass Spectrometry

(GC/MS) methods are available for milk and animal commodities. The stated quantitation limits are 

0.02-0.05 ppm for crop commodities, 0.01 ppm for milk, and 0.02 ppm for animal tissues. In

addition, the FDA PESTDATA database dated 11/01 (PAM Volume I, Appendix I) indicates that 

fluazifop-butyl (only) is completely recovered using Multiresidue Methods Sections 302 (Luke 

Method; Protocol D) and 303 (Mills, Onley, and Gaither Method; Protocol E, nonfatty food). 

To support this petition, the field trial samples were analyzed for residues of total fluazifop using a 

High Performance Liquid Chromatography/Mass Spectrometry/Mass Spectrometry (HPLC/MS/MS) 

protocol. This procedure is a common moiety method which works by hydrolyzing the fluazifop ester 

or acid conjugates so that a total determination can be made. This protocol is adequate for data 

collection based upon acceptable method validation and concurrent method recoveries. The validated 

Limit of Quantitation (LOQ) verified in potatoes is 0.010 ppm for this method.
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

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The proposed new uses included in this petition will request the establishment of tolerances on potato 

crops which are commonly recognized as being livestock feedstuffs. Given that these uses will be 

established on imported commodities, residues of fluazifop-P-butyl in/on potatoes will not result in 

being a contributor to the dietary burden of cattle. In accordance, it will not be necessary to provide a 

re-calculation of dietary burden in support of this action. The conclusions determined for the 

secondary transfer of fluazifop-P-butyl residues to meat, milk, poultry, and eggs made prior for the 

pending uses established on dry beans and peanuts remain current.

The submitted field trial data are adequate to support the proposed seasonal use pattern demonstrated 

on potatoes. The maximum residues of total fluazifop were 0.61 ppm in/on potatoes harvested at a 

PHI of 45 days following a single broadcast foliar application of the 250 g ai/ha EC formulation made 

at the 1x seasonal rate. These results demonstrate the application of the fluazifop-P-butyl herbicide 

made on potatoes within the various geographic/climatological production regions of Canada. The 

number and location of field trials were sufficient in scope since they were undertaken in line with the 

requirements set forth in the PMRA Regulatory Directive to evaluate this use. In accordance, MRID 

No. 47920402 contains 13 field trials and MRID No. 47920403 provides an additional 3 more to 

satisfy the Canadian requirement for a total of 16 studies in all. The field trial data were entered into 

the NAFTA tolerance/MRL spreadsheet which determines that a recommended tolerance of 1.0 ppm 

is appropriate for regulating residues of fluazifop-P-butyl in/on potatoes.

The submitted processing study is adequate in providing a determination of residue concentration 

factors for fluazifop-P-butyl in potato processed commodities. Processing of the potato Raw 

Agricultural Commodity (RAC) bearing quantifiable residues of fluazifop resulted in no 

concentration of residues in the peel (1.1x processing factor). However, total fluazifop residues were 

found to concentrate in the potato cooked product, chips and dried flakes at a processing factor of 

1.4x, 3.3x, and 6.4x, respectively. These data, along with the Highest Average Field Trial (HAFT)

residue, indicate that a tolerance limits are needed for fluazifop-P-butyl residues of concern in potato 

chips at 2.0 ppm and granules/flakes at 4.0 ppm.

Regulatory Recommendations and Residue Chemistry Deficiencies

Provided that a revised Section F is submitted, there no residue chemistry issues that would preclude 

establishing tolerance limits for the use of fluazifop in/on potatoes. The proposed uses and the 

submitted data support the following tolerances for total fluazifop residues (fluazifop-P-butyl and free 

and conjugated fluazifop-P) expressed as fluazifop, in/on:

Potato ...................................................................................1.0 ppm

Potato, chips.........................................................................2.0 ppm

Potato, granules/flakes.........................................................4.0 ppm

A new human health risk assessment which includes potatoes is forthcoming in a separate document.

860.1200 Directions for Use

The submitted bridging study data made for the Venture L and Fusilade Maxx EC formulations show 

that when they are applied to potatoes at 1x the maximum seasonal rate, the resulting residues will be 

similar. If the registrant so chooses, a revised section B could be submitted which includes this use 

for both product formulations. 
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

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860.1380 Storage Stability

Adequate storage stability data are available to support sample storage conditions incurred for the 

potato RAC, but none have been provided for the processed commodities. This is required since the 

processed commodities do not appear to have been analyzed within thirty (30) days of production.

860.1550 Proposed Tolerances

The proposed tolerances should be revised to reflect the recommended tolerance levels and correct 

commodity definitions as specified in Table 8. 

Background

Fluazifop-P-butyl [(R)-2-(4-((5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propanoic acid, butyl 

ester] is a selective herbicide used for the post-emergence control of perennial and annual grass 

weeds. It is the resolved isomer (R enantiomer) of fluazifop-butyl (PC code 122805) which has since 

been cancelled resulting in only fluazifop-P-butyl to be supported for re-registration. The fluazifopbutyl isomers are List B chemicals with parent and fluazifop-acid (free and conjugated) regulated for 

tolerance expression as the residues of concern used to determine misuse (DP No. D319907, S. L. 

Kinard, 08/17/2005). The Phase 4 Reviews for fluazifop-butyl and fluazifop-P-butyl were completed 

on 02/26/1991. The subsequent Phase 5 review of these studies has also been completed as well. 

This includes the Residue Chemistry Science Assessments with respect to the Report on FQPA 

Tolerance Reassessment Progress and Interim Risk Management Decisions (TRED) for fluazifop-Pbutyl issued on 08/17/2005. For review, the chemical structure and nomenclature of fluazifop-Pbutyl, including its free acid fluazifop-P as well as the physicochemical properties of the technical 

grade of fluazifop-P-butyl are presented below in Tables 1 and 2.

 

Table 1. Fluazifop-P-butyl Nomenclature.

Compound

N

F3C

O

O

H

CH3

O

O

C4H9(n)

Common name Fluazifop-P-butyl

Company experimental name Not available.

IUPAC name Butyl (2R)-2-(4-{[5-(trifluoromethyl)pyridin-2-yl]oxy}phenoxy)propanoate

CAS name (R)- 2-(4-((5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propanoic acid, butyl ester

CAS registry number 79241-46-6

End-use product (EP) Fusilade® DX (2 lb/gal EC; EPA Reg. No. 100-1070)

Compound

N

F3C

O

O

H

O

OH

CH3

Common name Fluazifop-P (free acid)

Chemical name (R)-2-(4-[5-(trifluoromethyl-2-pyridinyl)oxy]phenoxy)propionic acid
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

Page 6 of 23

Table 2. Physicochemical Properties of Fluazifop-P-butyl.

Parameter Value Reference1

Melting point/range Decomposes at 210 oC

164 oC at 0.02 mm Hg

2002 Farm Chemicals Handbook

RCB No. 1674, 2/3/87, L. Cheng

pH Not dispersible in water RCB No. 1674, 2/3/87, L. Cheng

Density 1.22 g/cc (PAI) and 1.20 g/cc (T) at 20 

oC

RCB No. 809, 6/3/86, L. Cheng

Water solubility 1 mg/L RCB No. 1674, 2/3/87, L. Cheng

Solvent solubility Soluble in most organic solvents

>500 g/L in acetone, dichloromethane, 

ethyl acetate, hexane, methanol, 

toluene, and xylene

2002 Farm Chemicals Handbook

RCB No. 1674, 2/3/87, L. Cheng

Vapor pressure 3 x 10-8 KPa at 20 oC RCB No. 809, 6/3/86, L. Cheng

Dissociation constant, pKa-3.1 (by calculation) RCB No. 809, 6/3/86, L. Cheng

Octanol/water partition coefficient, Log(KOW) 4.5 at 20 oC RCB No. 809, 6/3/86, L. Cheng

UV/visible absorption spectrum Not available

1DP No. D348246, D. Soderberg, 09/16/2008

860.1200 Directions for Use

A summary of the proposed/amended use patterns for cultivating potatoes are presented in Table 3. 

The information presented in Table 3 was obtained from a specimen label provided by Syngenta for 

the Venture L ® Herbicide (Canadian Reg. No. 21209).

Table 3. Summary of Directions for Use of Fluazifop-P-butyl.

Applic. Timing, Type, 

and Equip. 

Formulation

[EPA Reg. No.]

Max. No. Applic. 

per Season

Max. Seasonal 

Applic. Rate

(g ai/ha)

PHI

(days) Use Directions and Limitations

Potato

Postemergence

Ground

Venture L® Herbicide,

125 g ai/L EC

[21209]

1 250 45

May be mixed with Lexone or 

sencore formulations for early 

post emergent application. 

The general label use directions specify that the Venture L herbicide will be less effective when 

weeds are not growing rapidly because of stress from lack of moisture, excessive moisture, flooding, 

low temperature and/or very low humidity. Treatments should be applied to actively growing grass 

weeds that have 3 to 5 fully developed leaves for best results. Spray mist and drift is to be avoided 

with applications never to be made by aircraft or within 15 m of fish bearing waters. The use of 

adjuvants (crop oil concentrate, non-ionic surfactant, or other approved adjuvants) plus liquid 

nitrogen fertilizer may be used on specified crops such as soybeans and potatoes. 

Conclusions: The label directions are adequate to allow evaluation of the residue data relative to the 

proposed use on potatoes. 
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

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860.1300 Nature of the Residue - Plants

Residue Chemistry Memo, DP No. D319907, 08/17/2005, S. L. Kinard (TRED Residue Chemistry Chapter)

HED MARC Decision Memo, DP No. D298939, 06/22/2004, S. L. Kinard

The Fluazifop-P-Butyl Residue Chapter of the TRED (DP No. 319907, S. L. Kinard, 08/17/2005) 

concluded that the nature of the residue in soybeans is adequately understood. No new plant 

metabolism studies for the proposed new use crops were submitted as part of the current petition. The

MARC has determined that for tolerance expression, parent and fluazifop-acid (free and conjugated) 

are the residues of concern since they are adequate to determine misuse. The MARC also concluded 

that the residues of concern in plants for risk assessment are parent, fluazifop-acid (free and 

conjugated), 5-trifluoromethyl-2-pyridone, and 2-(4-hydroxyphenoxy) propionic acid (free and 

conjugated). 

860.1300 Nature of the Residue - Livestock

The MARC has concluded that for tolerance expression and risk assessment, parent and fluazifopacid (free and conjugated) are the residues of concern since they are adequate to determine misuse.

860.1340 Residue Analytical Methods

Residue Chemistry Memo, DP No. D319907, 08/17/2005, S. L. Kinard (TRED Residue Chemistry Chapter);

47920401.der.doc, Residue Analytical Method – Potato;

47920402.der.doc & 47920403.der.doc, Crop Field Trial /Residue Decline – Potato;

479204005.der.doc, Processed Food & Feed - Potato

Enforcement methods

For the enforcement of tolerances for fluazifop-P-butyl residues of concern, PAM Vol. II lists two 

methods, Method I for animal tissues and milk and Method II for oily and non-oily crops. The stated 

detection limits are 0.02-0.05 ppm for crops, 0.01 ppm for milk, and 0.02 ppm for animal tissues. In 

Method I, samples (except fat) are extracted with acetonitrile/acetone/hexane, which separates 

residues of fluazifop and fluazifop-butyl (found in the acetonitrile/acetone layer) from residues of 

fluazifop lipophilic conjugates (found in the hexane layer). Fluazifop and fluazifop-butyl are 

determined in milk using an HPLC/UV instrumental technique. In tissue samples, fluazifop-butyl is 

converted to fluazifop via hydrolysis, and then its residues are methylated using diazomethane, and 

determined by GC/MS. Fluazifop lipophilic conjugates (for both milk and tissue samples) are 

cleaned up by florisil chromatography, hydrolyzed to fluazifop, and determined by HPLC/UV. For 

fat, samples are extracted with chloroform/methanol at reflux (2 hours) and residues of fluazifop, 

fluazifop-butyl, and lipophilic conjugates are hydrolyzed to fluazifop, methylated, and determined by

GC/MS.

For Method II, residues of fluazifop-butyl, fluazifop, and any ester or acid conjugates are extracted 

from crop samples using acetonitrile and hydrochloric acid. Residues are then hydrolyzed to fluazifop 

and cleaned up using a coagulation procedure, solvent partitioning, and silica column chromatography

for determination by HPLC/UV. Residues may be confirmed by GC/MS following methylation with 

diazomethane. Consequently, neither of the enforcement methods distinguishes the optical isomers of 

fluazifop-butyl or fluazifop.
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

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Data collection methods (MRID No. 47920401)

For this petition, field trials acquiring samples of potato tubers were analyzed for residues of total 

fluazifop (fluazifop-P-butyl, fluazifop free and conjugated) using an HPLC/MS/MS protocol. This 

procedure entitled, “Fluazifop-P-Butyl: Residue Analytical Method for Total Fluazifop Analysis in 

Crops (Bolygo 1998)”, is denoted as Zeneca Method RAM 287/02. It is a common moiety method 

used for data collection which works by hydrolyzing the fluazifop ester or acid conjugates so that a 

total determination can be made. A complete copy of the original method, including any

modifications made to this procedure, was included in the submission. Likewise, a formal copy of the 

Zeneca RAM 287/02 protocol was also submitted as MRID No. 47920401 to support this petition

requesting a fluazifop-P-butyl import tolerance be established in/on potatoes. 

Method validation was conducted prior to the analysis of field samples using a series of blanks and 

untreated potato samples fortified at 0.01, 0.05, and 0.10 ppm. In doing so, the reported LOQ of 0.01 

ppm was demonstrated as being achievable in potatoes when using this method. Following the 

criterion of obtaining a minimal response of 3:1 signal/noise, the Limit of Detection (LOD) was thus 

established at 0.00330 ppm based upon fortifications analyzed at 3x below the LOQ. In addition, the 

performance of the method was likewise continuously monitored throughout this study by analyzing a 

series of blanks and fortified controls along with each analytical batch of samples. 

Samples of the potato RAC and its processed commodities were analyzed for total residues of 

fluazifop (fluazifop-P-butyl, fluazifop free and conjugated) using a GC/MS protocol. This procedure 

entitled, “Gaschromatograpische Bestmmung von Fluazifop und Fluazifop-P-butyl in Pflanzlichem 

Material”, is denoted as laboratory test protocol P-14.077. It is a common moiety method which 

works by forming the methyl ester of fluazifop through extraction so that a total determination can be 

made. A detailed summary of the original method was provided within the submission.

The validated LOQ for this methodology is 0.01 ppm for fluazifop-P-butyl expressed as total 

fluazifop in all potato matrices. It is based upon the analysis of untreated samples fortified with 

fluazifop-P-butyl worked up concurrently with the determination of the treated unknowns. The 

validated LOQ is therefore defined as the lowest fortification level yielding acceptable recoveries 

(70–120 % R) at analysis. In addition, method performance was also monitored throughout the study

by analyzing a series of blanks and fortified controls along with each analytical batch of samples.

Conclusions. The existing GC/MS enforcement method, or this modified version, is adequate for 

collecting data on residues of fluazifop in/on potato commodities. It is adequate for enforcing 

tolerances on these commodities. The data collection methods used by the registrant were likewise 

shown to be adequate for determining the magnitude of fluazifop residues in potato commodities 

acquired in support of this petition. 

860.1360 Multiresidue Methods

Residue Chemistry Memo, DP No. 319907, 08/17/2005, S. L. Kinard (TRED Residue Chemistry Chapter)

The FDA PESTDATA database dated 11/01 (PAM Volume I, Appendix I) indicates that fluazifopbutyl is completely recovered using Multiresidue Methods Sections 302 (Luke Method; Protocol D) 

and 303 (Mills, Onley, and Gaither Method; Protocol E, nonfatty food); recovery using Section 304 

(Mills Method; Protocol F, fatty food) is variable.
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

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860.1380 Storage Stability

Storage stability data have been reviewed in conjunction with earlier actions undertaken for fluazifopP-butyl which indicate that its residues are stable in a wide variety of crop commodities. As such, its 

stability in frozen potatoes has previously been investigated in prior reports generated by Syngenta. 

These reports show that fortified potatoes demonstrate no loss of fluazifop-p-butyl when stored frozen 

at -18°C for 18 months (DP No. D348246, D. Soderberg, 09/16/2008). Given the results obtained 

from the prior stability study made on potatoes, adequate data are available to support the sample 

storage intervals and conditions incurred in the field trial submissions. Although adequate data are 

available to support sample storage conditions of the potato RAC, none were provided to substantiate 

the holding times that were incurred for the processed commodities. This is required since the 

processed commodities do not appear to have been analyzed within thirty (30) days of production. A 

summary of the storage durations and conditions of the samples from the crop field trials and 

processing studies provided to support this petition are presented below in Table 4 for review. 

Table 4. Summary of Storage Conditions.

Matrix Storage Temperature (°C) Actual Storage Duration1Interval of Demonstrated Storage Stability

Potato/

MRID No. 47920402

≤-10 °C 63-142 days

(2.1-4.7 months)

5482- Total fluazifop residues appear 

relatively stable under frozen conditions 

in/on potatoes for up to 18 months.

Potato/

MRID No. 47920403

≤-10 °C 94-142 days

(3.1-4.7 months)

5482- Total fluazifop residues appear

relatively stable under frozen conditions 

in/on potatoes for up to 18 months.

Potato 

Processing/

MRID No. 

47920402

Tuber ≤-18 °C 200 days (6.7 months) 5482- Total fluazifop residues appear 

relatively stable under frozen conditions 

in/on potatoes for up to 18 months.

Peel None.

Cooked

Chips

Granules/Flakes

1

 Actual storage duration from harvest to analysis.

2

 DP No. 348246, D. Soderberg, 09/16/2008.

Conclusions: Previously submitted storage stability data demonstrate that total residues of fluazifopP-butyl are stable in/on variety of crops which include the potato RAC. These data are adequate in 

supporting all of the potato RAC sample storage conditions and durations that were incurred for 

testing relevant to this petition request (PP#9E7651). However, no data were provided to substantiate 

the holding times that were incurred for any of the potato processed commodities which were 

analyzed. Given that none of the processed potato fractions appear to have been analyzed within 

thirty (30) days of production, additional stability data may be required for these commodities.

860.1400 Water, Fish, and Irrigated Crops

For the purpose of this summary, this guideline requirement is not relevant to this evaluation since 

Fluazifop-P-butyl has no registered or proposed uses on water or aquatic food and feed crops.
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

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860.1460 Food Handling

For the purpose of this summary, this guideline requirement is not relevant to this evaluation since 

Fluazifop-P-butyl has no food-handling uses which are being proposed.

860.1480 Meat, Milk, Poultry, and Eggs

Residue Chemistry Memo, DP No. D348246, 09/16/2008, D. Soderberg (PP#7F7289 Residue Chemistry Chapter)

In evaluating the data provided to support this petition, the establishment of tolerance limits will be 

recommended for several RACs commonly recognized for use as livestock feedstuffs. This would 

include establishing tolerance limits for citrus dried pulp and sugar beet tops which are requested in 

part with this action. The maximum theoretical dietary burdens to livestock were previously

evaluated in the prior residue chemistry chapter prepared to support pending uses on dry beans and 

peanuts (DP No. D348246, D. Soderberg, 09/16/2008). The resulting theoretical dietary burdens of 

fluazifop-P-butyl to livestock were put forward with the updated version of Table 1 (Table 1 

Feedstuffs June 2008) and are presented below in Table 5 for review.

Table 5. Calculation of Dietary Burdens of Fluazifop-P-butyl Residues to Livestock.

Feedstuff Type1 % Dry 

Matter2 % Diet2 Recommended Tolerance (ppm)

Dietary Contribution 

(ppm)

3

Beef Cattle

Soybean, hulls R 90 20 2.5 0.555

Untreated CC CC NA 65 NA 0

Soybean, meal PC 92 15 2.5 0.408

TOTAL BURDEN -- -- -- 0.963

Dairy Cattle

Soybean, hulls R 90 15 2.5 0.417

Untreated R R NA 30 NA 0

Carrot, culls CC 12 10 2.0 1.667

Untreated CC CC NA 35 NA 0

Soybean, seed PC 89 15 2.5 0.421

TOTAL BURDEN -- -- -- 2.505

Poultry

Untreated CC CC NA 75 NA 0

Soybean, meal PC -- 25 2.5 0.625

TOTAL BURDEN -- -- -- 0.625

Swine

Untreated CC CC NA 85 NA 0

Soybean, meal PC -- 15 2.5 0.375

TOTAL BURDEN -- -- 0.375

1

 R: Roughage; CC: Carbohydrate concentrate; PC: Protein concentrate.

2

 OPPTS 860.1000 Table 1 Feedstuffs (June 2008). 

3

 Contribution = ([tolerance /% DM] X % diet) for beef and dairy cattle; contribution = ([tolerance] X % diet) for poultry 

and swine. 

4

 N/A: Not applicable. Tolerances/uses of Fluazifop-P-butyl have not been registered or proposed for this feedstuff. 
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

Page 11 of 23

These calculations are considered tentative because plant and animal metabolism studies remain 

outstanding and additional field trials are required for some crops. It was also noted that there are 

label restrictions against the grazing or harvesting of peanut hay as well as soybean forage and hay

which are appropriate according to Table 1 of 860.1000. In all, the addition of the use on peanut did

not affect the theoretical dietary burden of fluazifop residues to livestock. Soybeans were found to 

have a larger impact and these matrices were incorporated into the previous dietary burden 

calculations. The effect of use on cowpea forage and hay along with residues on the soybean 

aspirated grain fractions will be evaluated after these data have been submitted. Prior calculated 

dietary burden maximums of fluazifop-P-butyl were reported to beef/dairy cattle at 4.49 ppm, 1.00 

ppm to poultry, and 0.70 ppm to swine. These differ significantly from the updated values presented 

in Table 5 due to the current calculations being based on a “reasonably balanced” diet and the 

reduction in the diet percentage for carrot culls.

 

Nonetheless, in assessing the new uses pursuant to this petition, potato crops are commonly

recognized as being livestock feedstuffs. Given that these uses will be established as import 

tolerances, residues of fluazifop-P-butyl in/on potatoes will not result in being a contributor to the 

dietary burden of cattle. As a result, it will not be necessary to provide a re-calculation of dietary

burden in support of this action. The prior calculations tentatively depicting the secondary transfer of 

fluazifop-P-butyl residues to meat, milk, poultry, and eggs made for the pending uses established on 

dry beans and peanuts remain current.

Conclusions: No change in the tolerances of meat, milk, poultry, and eggsis needed at this time. 

860.1500 Magnitude of the Residue in Crops

DER References: 47920402.der.doc (potato – 13 trials)

47920403.der.doc (potato – 3 trials)

For this current petition, Syngenta is requesting that a new import tolerance for the residues of 

fluazifop-P-butyl in/on potatoes and its processed commodities be established. To satisfy data 

requirements, field trial studies have been made on potatoes within the various 

geographic/climatological production regions of Canada and submitted by the registrant to support 

this petition. The number and location of field trials were sufficient in scope since they were 

undertaken in line with the requirements set forth in the PMRA Regulatory Directive to evaluate this 

use. In accordance, MRID No. 47920402 contains 13 field trials and MRID No. 47920403 provides 

an additional 3 more to satisfy the Canadian requirement for a total of 16 studies in all. A summary

of the residue data acquired from these field trial studies which were undertaken are presented below 

in Table 6.

Table 6. Summary of Residue Data from Crop Field Trials with Fluazifop-P-butyl.

Commodity Total Rate

(g ai/ha)

PHI 

(days)

End-Use

Product

Residue Levels

(ppm)

n Min. Max. HAFT1 Median2

(STMdR)

Mean2

(STMR)

Std. Dev.2

Potato 0.250 44-46 Venture L 32 < 0.0033 0.61 0.55 0.065 0.11 0.13

1

 HAFT = Highest Average Field Trial.

2

For mathematical purposes, in the calculation of the median, mean, and standard deviation, 0.00165 ppm (half the LOD) was used for 

residues reported as less than the LOD (<0.0033 ppm).

3 Not Applicable (NA).
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

Page 12 of 23

Potatoes (MRID No. 47920402)

To determine the magnitude of fluazifop-P-butyl residue found in/on potatoes within the various 

production regions of Canada, thirteen (13) field trials were conducted during the 2008 growing 

season. The thirteen (13) field trials held for this study were carried out in Canadian growing zones 1, 

1A, 5, 5B, 7A, 12 and 14 all of which are known to be significant potato cultivation regions of the 

country. As such, two trials were held at New Glasgow, Elm Creek, and Malden along with single 

ones made at Albany, Branchton, St. Marc-sur-Richeilieu, Taber, Abbotsford, Minto, and Innisfall.

Each trial site was managed according to the practices routinely followed by Canadian commercial 

producers for cultivating potatoes. Test plots were roughly 10-100 square meters in size, large 

enough to provide a 1 Kg sample of mature potato tubers to be collected from at least six (6) different 

plants. 

At each study location, market quality potato samples were cultivated using both untreated control 

and treated test plots. Each treated test plot received a single application of the VENTURE L end-use 

product made at the maximum labeled rate of 250 g ai/ha so that late seasonal treatments could be 

evaluated. In doing so, this comparison will provide sufficient data to support establishing a PreHarvest Interval (PHI) of 45 days in addition to currently registered early seasonal treatments made at 

90 days. The actual rate of application ranged from 94.2% to 103.4% of the targeted amount of 

product designated for treatment. The treatment regimen also included two (2) residue decline studies 

made at the New Glasgow and Elm Creek sites with samples collected at -7, 0, +7, +14 and +21 days 

of normal commercial harvest. The application procedure followed was typical of the local 

agricultural practices with treatments being made using either tractor-mounted or hand-held boom 

sprayers. No adjuvant was added to the spray mixture for any of the applications. 

To perform the determination of total fluazifop residues in/on potatoes, an acceptable method was 

used and adequate data are available to support the sample storage durations of up 143 days that were 

incurred. Total residue levels were observed ranging at levels between <0.0033 - 0.61 ppm for 

treatments made at the late seasonal timed PHI of 45 days (± 1 day) using the VENTURE L 

formulation of fluazifop. The results generated in the two decline studies illustrate demonstrate that 

concentrations of fluazifop will in fact decrease as greater PHIs for treatment are followed. In all, 

these data are adequate to support the proposed seasonal use pattern on potatoes put forward in this 

study. A summary of the residue data obtained from the potato field trials made for this study are 

presented below in Table 7 for review.

Table 7. Residue Data from Crop Field Trials with Fluazifop-P-butyl Presented in MRID No. 47920402.

Trial: City, Province; Year

(Trial ID #)

Zone Potato; 

Variety

# of 

Treatments

Total Rate 

(g ai/ha)

PHI 1

(days)

End-Use

Product

Total

Fluazifop

(ppm)

New Glasgow, PEI; 2008 (T455) 1A Shepody 1 250 46 Venture L 0.16, 0.08

Albany, PEI; 2008 (T456) 1A Carlingford 1 250 36 Venture L < LOD2, <LOD

New Glasgow, PEI; 2008 (T457

– Decline Study)

1A Goldrush 1 250 39 Venture L 0.28

46 0.61, 0.49

53 0.32

60 0.37

68 0.34
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

Page 13 of 23

Table 7. Residue Data from Crop Field Trials with Fluazifop-P-butyl Presented in MRID No. 47920402.

Trial: City, Province; Year

(Trial ID #)

Zone Potato; 

Variety

# of 

Treatments

Total Rate 

(g ai/ha)

PHI 1

(days)

End-Use

Product

Total

Fluazifop

(ppm)

Malden, NB; 2008 (T458) 1 Red 

Norland

1 250 46 Venture L 0.035, 0.036

Malden, NB; 2008 (T459) 1 Goldrush 1 250 46 Venture L 0.27, 0.28

Branchton, ON; 2008 (T460) 5 Goldrush 1 250 45 Venture L < LOQ3

(0.0070), 0.016

Elm Creek, MB; 2008 (T461 –

Decline Study)

5 Shepody 1 250 37 Venture L 0.020

44 0.016, 0.012

51 0.024

58 < LOQ 

(0.0070)

65 0.020

Elm Creek, MB; 2008 (T462) 5 Russet 

Burbank

1 250 44 Venture L < LOQ 

(0.0052), 0.036

St. Marc-sur-Richelieu, QC: 

2008 (T463)

5B Kennebec 1 250 45 Venture L 0.044, 0.037

Taber, AB; 2008 (T464) 7A Russet 

Burbank

1 250 46 Venture L 0.14, 0.20

Abbotsford, BC; (T465) 12 WanBa 1 250 44 Venture L 0.043, 0.035

Minto, MB; 2008 (T466) 14 Norland 1 250 46 Venture L 0.14, 0.16

Innisfall, AB; 2008 (T467) 14 Russet 

Burbank

1 250 45 Venture L 0.065, 0.050

1

 PHI = Preharvest interval; interval from last application to harvest (petitioner reported PHI based on collection date).

2

 LOD = Limit of Detection; 0.0033 ppm.

3

 LOQ = Limit of Quantitation; 0.01 ppm.

Potatoes (MRID No. 47920403)

To determine the magnitude of fluazifop-P-butyl residue found in/on potatoes within the various 

production regions of Canada, three (3) field trials were conducted during the 2007 growing season. 

The three (3) field trials were held at Hunter River (2 trials) and Portage la Prairie (1 trial) in Canada 

all of which are located in significant potato growing regions of the country. Each trial site was 

managed according to the practices routinely followed by Canadian commercial producers for 

cultivating potatoes. Test plots were roughly 40-45 square meters in size, large enough to provide a 1 

Kg sample of mature potato tubers to be collected from at least six (6) different plants. 
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

Page 14 of 23

At each study location, market quality potato samples were cultivated using both untreated control 

and treated test plots. Each treated test plot received a single application made at the maximum 

labeled rate of 250 g ai/ha timed so that early, mid and late seasonal treatments could be evaluated. 

This treatment program also included field testing the application of the VENTURE L and 

FUSILADE MAXX fluazifop-p-butyl end-use products using side-by-side test plots. This 

comparison was only made for treatments those timed at the early seasonal application interval as a 

means for providing bridging data on these EC formulations. The actual rate of application ranged 

from 92.5% to 103.6% of the targeted amount of product designated for treatment. The application 

procedure followed was typical of the local agricultural practices with treatments being made using 

either tractor-mounted or hand-held boom sprayers. No adjuvant was added to the spray mixture for 

any of the applications. 

For the determination of total fluazifop residues in/on potatoes, an acceptable method was used and 

adequate data are available to support the sample storage durations of up 142 days that were incurred. 

Total residue levels were all observed to be at or below the LOQ (0.010 ppm) for treatments made at 

early seasonal timed PHIs (89-90 days) using both fluazifop formulations. In conjunction, residue 

levels for mid-seasonal timed PHIs (60-61 days) were found to range from 0.024- 0.130 ppm and lateseasonal timed PHIs (46 days) at 0.065- 0.170 ppm. In all, these data are adequate to support the 

proposed seasonal use pattern on potatoes put forward in this study. A summary of the residue data 

obtained from the potato field trials made for this study are presented below in Table 8 for review.

Table 8. Residue Data from Crop Field Trials with Fluazifop-P-butyl Presented in MRID No. 47920403.

Trial: City, Province; Year

(Trial ID #)

Zone Potato; Variety # of 

Treatments

Total Rate 

(g ai/ha)

PHI 1

(days)

End-Use

Product

Total

Fluazifop

(ppm)

Hunter River, PEI; 2007 

(T232)

1A Russet Burbank 1 250 90 Venture L < LOD2, <LOD

Fusilade Maxx < LOD, <LOD

60 Venture L 0.042, 0.038

46 Venture L 0.065, 0.072

Hunter River, PEI; 2007 

(T233)

1A Yukon Gold 1 250 90 Venture L < LOD, <LOD

Fusilade Maxx < LOD, <LOD

60 Venture L 0.13, 0.11

46 Venture L 0.093, 0.085

Portage la Prairie, MB; 2007 

(T234)

5 Burbank 1 250 89 Venture L < LOD, <LOD

Fusilade Maxx 0.0048, <LOD

61 Venture L 0.024, 0.024

46 Venture L 0.17, 0.14

1

 PHI = Preharvest interval; interval from last application to harvest (petitioner reported PHI based on collection date).

2

 LOD = Limit of Detection; 0.0033 ppm.
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

Page 15 of 23

Conclusions: The submitted residue data made for potato tubers are adequate in fulfilling these data 

requirements. The number and location of field trials were in line with the Canadian regulatory

requirements. To satisfy the Canadian requirement for a total of 16 trials in all, the results from two 

studies were compiled to provide a complete data submission. MRID No. 47920402 contains 13 field 

trials and MRID No. 47920403 provides an additional 3 more made on the premise of a bridging 

study for showing the equivalency of Venture L and Fusilade Maxx EC formulations. In regard to 

this comparison, this bridging data along with the supplemental information in the CSF summary of 

each end-use product adequately demonstrate these end-use products to be equivalent. Nonetheless, 

the trials which were made appropriately reflect the proposed use pattern, and supporting storage 

stability data are available. The residue data compiled for the potato RAC were entered into the 

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

on Field Trial Data SOP to determine an appropriate regulatory level (Appendix I). The resulting 

spreadsheet provides a best estimate of a tolerance which is determined to be 1.0 ppm for the potato 

RAC.

860.1520 Processed Food and Feed

DER References: 47920405.der.doc (potato)

For this action, Syngenta is requesting the establishment of a new import tolerance for residues of 

fluazifop-P-butyl in/on potatoes and its processed commodities. To satisfy data requirements, the 

registrant has submitted a processing study made for this herbicide ai on potatoes. A summary of the 

data acquired from this processing study is presented below in Table 9.

TABLE C.3. Residue Data from Potato Processing Study with Fluazifop-P-butyl.

Trial: City, State; 

Year (Trial ID#)

Processed Commodity Total Rate

(g ai/ha) 

PHI 

(days)

Residues (ppm) Processing Factor1

Büchen, Germany; 

1993 (B2)

Potato RAC (w/peel) 375 42 0.22 --

Potato Peel 0.25 1.1x

Cooked Potato 0.32 1.4x

Potato Chips 0.72 3.3x

Dried Potato 1.41 6.4x

1

 The processing factor was calculated by the study reviewer by dividing the residues in the processed sample by the residues in the 

unprocessed RAC sample. 

Potato (MRID No. 47920405)

The field portion of this study was carried out by ZENECA AGRO based in Frankfurt using six (6) 

field trials held at separate sites within Germany to cultivate potatoes during the 1993 growing 

season. No details concerning the varieties of potatoes that were grown, the use of any maintenance 

pesticides and fertilizers, soil chemistry, weather data, or the use of supplemental irrigation was 

provided. The data submission only noted that each test location received an application of the 

Fusilade end-use product formulation of fluazifop-P-butyl applied at a late seasonal Pre-Harvest 

Interval (PHI) of six weeks. These treatments were made at the targeted amount of 375 g ai/ha in 

order to provide each test plot with a total seasonal application that was equivalent to 1.5x the 

maximum labeled use rate. For this program, the field samples from the two trials observed with the 

highest residues of total fluazifop were processed into potato peels, cooked potatoes, chips and dried 

flakes for testing. 
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

Page 16 of 23

For this study, the cultivation of market quality potato samples was made using individual untreated 

control and treated test plots. The collected potato samples were shipped chilled at temperatures of 4-

6° C via common carrier to the laboratory of DR. SPECHT & PARTNER (Hamburg, Germany) for 

processing. In doing so, this study would clarify how residues of fluazifop which may be present in 

harvested potatoes degrade or concentrate when processed by typical household preparation methods. 

For these purposes, the samples from the Bienenbüttel-Varendorf and Büchen trials with the highest 

observed residues of total fluazifop were processed. All samples were stored frozen at the laboratory

until processing which was initiated a week after harvest. Representative mixed samples were formed 

and processing was then carried out according to laboratory SOP# Q-51.037.02 in order to simulate 

normal domestic preparation procedures. The potato processing procedure was as follows (MRID

No. 447920405):

1. Cooked Potatoes

About 2 Kg of peeled potatoes were covered with 2 L of water and brought to a boil after the 

addition of 10 g of common salt. The potatoes were cooked for 20–25 minutes and then 

drained with the cooking liquid kept separately. 

2. Chips

About 2 Kg of peeled potatoes were cut into slices. Approximately 1 Kg of fat was heated in 

a deep-frying-pan, and fried for 20 minutes.

3. Dried Potatoes

About 1.5 Kg of peeled potatoes were sliced, distributed evenly on the racks of the desiccation 

apparatus and dried at level 3 for 6–8 hours.

4. Freezing

The processed potatoes were frozen prior to analysis. Before freezing cooked potatoes were 

homogenized, chips and dried potatoes were chopped coarsely.

Sample storage conditions and durations are summarized in Table C.2. Based upon the information 

provided, the approximate maximum storage duration of the potato samples from harvest/processing 

to analysis did not exceed 200 days (≈6.7 months) for the study. To support the storage interval of the 

samples collected for this study, the stability of fluazifop-P-butyl in frozen potatoes has previously

been investigated in prior reports generated by Syngenta. These reports show that fortified potatoes 

demonstrate no loss of fluazifop-p-butyl when stored frozen at -18°C for 18 months (DP No. 

D348246, D. Soderberg, 09/16/2008). However, storage stability data are required to support the 

storage conditions and durations of the processed commodities.

The results in this data submission provide a determination of residue concentration factors for 

fluazifop-P-butyl in potato processed commodities. It was appropriately carried out in line with the 

recommendations set forth in the OPPTS 860.1520 Residue Chemistry Test Guidelines for evaluating 

the concentration of residues in processed commodities. Processing of the potato RAC bearing 

quantifiable residues of fluazifop resulted in no concentration of residues in the peel (1.1x processing 

factor). However, total fluazifop residues were found to concentrate in potato chips and dried flakes 

at a processing factor of 3.3x, and 6.4x, respectively. In all, these data are adequate for determining 

residue concentration factors for potato processed commodities. 
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

Page 17 of 23

Conclusions. The potato processing results acquired in this study are adequate for satisfying these 

data requirements. These results indicate that total fluazifop residues do not appear to concentrate in 

the potato peels, but may do so in the chips and granules/flakes processed fractions. Residues of total 

fluazifop were therefore found to concentrate in potato chips and granules/flakes at processing factors 

of 3.3x and 6.4x, respectively. Based on the HAFT residue for potato (0.55 ppm) and these 

processing factors, expected residues are 1.81 ppm in chips and 3.52 ppm for granules/flakes. In 

comparison, the expected residues of these processed fractions are greater then the 1.0 ppm 

recommended tolerance for potato. Potato tolerances of 2.0 ppm in chips and 4.0 ppm for 

granules/flakes are thus recommended with no limits in peels being required. 

860.1650 Submittal of Analytical Reference Standards

Analytical standards for fluazifop-p-butyl and fluazifop-p (resolved (R) isomer of fluazifop acid) are

currently available in the EPA National Pesticide Standards Repository. The fluazifop-p-butyl 

standard expires 1/1/2011. Analytical reference standards must be replenished as requested by the 

Repository. The reference standards should be sent to the Analytical Chemistry Lab, which is located 

at Fort Meade, to the attention of either Theresa Cole or Thuy Nguyen at the following address:

USEPA

National Pesticide Standards Repository/Analytical Chemistry Branch/OPP

701 Mapes Road

Fort George G. Meade, MD 20755-5350

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

860.1850/860.1900 Confined and Field Accumulation in Rotational Crops

The following plantback restriction exists on the product label (EPA Reg. No. 100-1070): a 60-day

plantback interval for rotational crops such as corn, sorghum, and cereals. This plantback interval is 

also appropriate for sugar beet.

860.1550 Proposed Tolerances

In a meeting on March 3, 2004, the MARC concluded that for tolerance expression, parent and 

fluazifop-acid (free and conjugated) are the residues of concern since they are adequate to determine 

misuse (DP No. D298939, S. L. Kinard, 06/22/2004). An acceptable soybean metabolism study is 

available along with new studies made to a root crop and leafy vegetable which are currently

undergoing Agency review. In accordance, tolerances are established under 40 CFR §180.411(a)(1) 

and (c)(1) for residues of fluazifop-butyl, including free and conjugated fluazifop, expressed as 

fluazifop. For fluazifop-P-butyl, including free and conjugated fluazifop (R isomer), tolerances are 

likewise established under 40 CFR §180.411(a)(2) and (c)(2) with residues expressed as fluazifop. Its 

registered uses include asparagus, carrot, coffee, cotton, endive (escarole), garlic, macadamia nut, 

onion, pecan, pepper, rhubarb, soybeans, stone fruits, sweet potato, and yam. It also carries a 

registration for use on lawns as a weed control application. Subsequently, a petition for establishing 

tolerance limits on dry beans and peanuts is currently pending. 
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

Page 18 of 23

For this action, field trials on potatoes along with a corresponding study made on its pertinent 

processed commodities were submitted to support this petition request. In evaluating the field trials 

provided by the registrant, these studies were found to be adequate in satisfying these residue 

chemistry data requirements. Total fluazifop residues in/on the potato RAC were found to be readily

quantifiable at levels greater then the LOQ of the test method. In accordance, the Agency’s Guidance 

for Setting Pesticide Tolerances Based on Field Trial Data was utilized for determining appropriate 

tolerance levels for potato tubers (Appendix I). Based on these calculations, the proposed potato 

tolerance of 0.25 in roots is adequate and a limit of 1.0 ppm for tops is recommended. In regard to the 

corresponding processing study data that were provided, it can be concluded that no additional 

tolerances are needed for the peel. However, residues of fluazifop were found to concentrate in potato

chips (3.3x) and dried flakes (6.4x). Based on the potato HAFT of 0.55 ppm and the processing 

factors calculated for chips and dried flakes, expected residues in these fractions are 1.82 ppm and 

3.52 ppm, respectively. As a result, the tolerances of 2.0 ppm in chips and 4.0 ppm for dried flakes 

are recommended for these potato processed commodities.

The proposed new uses included in this petition will request the establishment of tolerances on potato 

crops which are commonly recognized as being livestock feedstuffs. Given that these uses will be 

established on imported commodities, residues of fluazifop-P-butyl in/on potatoes will not result in 

being a contributor to the dietary burden of cattle. In accordance, it will not be necessary to provide a 

re-calculation of dietary burden in support of this action. The conclusions determined for the 

secondary transfer of fluazifop-P-butyl residues to meat, milk, poultry, and eggs made prior for the 

pending uses established on dry beans and peanuts remain current.

The established tolerances for livestock commodities are 0.05 ppm for total fluazifop residues in milk 

and the meat and meat byproducts of cattle, goat, hog, horse, and sheep, and fat, meat and meat 

byproducts of poultry. These levels remain appropriate.

In all, the available residue data provided for fluazifop-P-butyl are adequate to support the 

establishment of new import tolerance levels recommended for the potato RACs proposed in this 

action. There are no Codex or Mexican established Maximum Residue Limits (MRLs) for residues of 

fluazifop-P-butyl in/on potatoes. However, this petition is being put forward as a request for the 

establishment of import tolerances on potato commodities which will be cultivated in Canada. There 

are no established MRLs for residues of fluazifop-P-butyl in/on potatoes in Canada but the 

promulgation of regulatory levels by PMRA are in the process of being finalized. As a result, 

international harmonization with Canada is a consideration for this data evaluation concerning the 

establishment of tolerances on imported potato commodities. The proposed limits should therefore be 

revised and a new Section F submitted to reflect the recommended tolerance levels and correct 

commodity definitions specified below in Table 8.

Table 8. Tolerance Summary for Fluazifop-P-butyl.

Commodity Established 

Tolerance 

(ppm)

Proposed 

Tolerance 

(ppm)

Recommended 

Tolerance 

(ppm)

Comments; Correct Commodity 

Definition

Tolerances Proposed for 40 CFR §180.411(a)(1)

Potato, tubers -- 1.1 1.0 Potato

Potato, chips -- 3.0 2.0

Potato, granules/flakes -- 5.0 4.0
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

Page 19 of 23

References

DP No.: D319907

Subject: Fluazifop-P-butyl. REVISED TRED – Report on FQPA Tolerance Reassessment 

Progress and Interim Risk Management Decisions. Residue Chemistry Considerations. 

Case No. 2285.

From: S. L. Kinard

To: D. Locke

Dated: 08/17/2005

MRID Nos.: 00093840-1, 00093843, 00093845, 00137763, 00144014, 00151494, 00157191, 

001517193, 40140401, 40241901, 40341601, 40361104, 40361108, 40361111, 

40693108, 40725701, 40831303-5, 40831307, 40831309-10, 41018001, 41373703.

DP No.: D298939

Subject: Fluazifop-P-butyl. Report of the Metabolism Assessment Review Committee. 

From: S. L. Kinard

To: Y. Donovan

Dated: 03/17/2004

MRIDs: None

DP No.: D348246

Subject: Fluazifop-P-Butyl. Section 3 Registration Request to Add New Uses on Beans (Dry), 

Peanuts and Soybeans. Summary of Analytical Chemistry and Residue Data.

From: D. Soderberg

To: J. Miller

Dated: 9/16/2008

MRID Nos.: 47285501-05; 46412503

Attachments: 

International Residue Limit Status sheet

Appendix I - Tolerance Assessment Calculations

Template Version September 2005
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

Page 20 of 23

International Residue Limits 

Fluazifop-P-butyl (122809; 08/26/2010)

Summary of US and International Tolerances and Maximum Residue Limits 

Residue Definition:

US Canada Mexico2 Codex3

40 CFR 180.411:

Plant/Livestock: butyl(R)-2-[4-[[5-

(trifluoromethyl)-2-

pyridinyl]oxy]phenoxy]propanoate, and the 

free and conjugated forms of the resolved 

isomer of fluazifop, (R)-2-[4-[[5-

(trifluoromethyl)-2-

pyridinyl]oxy]phenoxy]propanoic acid, 

expressed as fluazifop.

butyl (RS)-2-[4-[[5-

(trifluoromethyl-2-

pyridinyl]oxy]phenoxy]

propanoate

(calculated as acid)

None

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

US Canada Mexico2 Codex

Potato, tubers 1.0 None None

Potato, chips 2.0

Potato, granules/flakes 4.0

Completed: M. Negussie/08/30/2010

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.

3 * = absent at the limit of quantitation; Po = postharvest treatment, such as treatment of stored grains. PoP = processed 

postharvest treated commodity, such as processing of treated stored wheat. (fat) = to be measured on the fat portion of the 

sample. MRLs indicated as proposed have not been finalized by the CCPR and the CAC.
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

Page 21 of 23

Appendix I

Tolerance Assessment Calculations

For each of the crops listed below, the Guidance for Setting Pesticide Tolerances Based on Field 

Trial Data (SOP), along with the tolerance spreadsheet (January 2008 version), was used for 

calculating recommended tolerances.

Potato, tubers

The dataset used to establish a tolerance for fluazifop-P-butyl on potatoes consisted of field trial data 

representing application of the VENTURE L end-use product made at the maximum labeled rate of 

250 g ai/ha with a 45 day PHI. As specified by the Guidance for Setting Pesticide Tolerances Based 

on Field Trial Data SOP, the field trial application rates and PHIs are within 25% of the maximum 

label application rate and minimum label PHI, respectively. The residue values used to calculate the 

tolerance are provided in Table I-1.

Most of the 32 field trial sample results were above the LOQ (LOQ = 0.01 ppm). The fluazifop-Pbutyl-dry potato dataset was entered into the tolerance spreadsheet. Visual inspection of the 

lognormal probability plot (Figure I-1) provided in the spreadsheet indicates that the dataset is 

reasonably lognormal. The result from the approximate Shapiro-Francia test statistic (Figure I-2) 

confirmed that the assumption of log normality should not be rejected.

Since the field trial data for fluazifop-P-butyl on potato represent a large dataset (i.e., more than 15 

samples) and are reasonably lognormal, the minimum of the 95% upper confidence limit (UCL) on 

the 95th percentile and the point estimate of the 99th percentile should be selected as the tolerance 

value. Using the rounding procedure as outlined in the Guidance for Setting Pesticide Tolerances 

Based on Field Trial Data SOP, the 95% UCL on the 95th percentile rounds to the value 0.80 ppm. 

For the use, the recommended tolerance level for potato tubers is 1.0 ppm based upon this minimum 

value found in the UCL of the 95th percentile.
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

Page 22 of 23

Table I-1. Residue data used to calculate tolerance for fluazifop-P-butyl on dry bean.

Regulator: EPA

Chemical: Fluazifop-P-butyl

Crop: Potato, tubers

PHI: 45 Days

App. Rate: 250 g ai/ha (1 application)

Submitter: Syngenta Crop Protection, Inc.

MRID Citation: MRID Nos.: 47920402 & 47920403

Total Fluazifop Residues (Fluazifop-P-Butyl and Fluazifop free and 

conjugated as Fluazifop) (ppm)

0.010

0.010

0.010

0.010

0.012

0.016

0.016

0.035

0.035

0.036

0.036

0.037

0.043

0.044

0.050

0.065

0.065

0.072

0.080

0.085

0.093

0.140

0.140

0.140

0.160

0.160

0.170

0.200

0.270

0.280

0.490

0.610
Fluazifop-P-butyl Summary of Analytical Chemistry and Residue Data DP No. 372408

Page 23 of 23

Figure I- 1. Lognormal probability plot of fluazifop-P-butyl field trial data for potatoesbean.

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

0.0078

y = 1.1758x - 2.7884

R

2

 = 0.9691

Percentiles

Concentrations

EPA Fluazifop-P-Butyl Potato (Import) 45 day PHI 0.250 lb ai/A Syngenta

Figure I- 2. Tolerance spreadsheet summary of fluazifop-P-butyl field trial data for potatoes.

Regulator: EPA

Chemical: Fluazifop-P-Butyl

Crop: Potato (Import)

PHI: 45 day PHI

App. Rate: 0.250 lb ai/A

Submitter: Syngenta

n: 32

min: 0.01

max: 0.61

median: 0.07

average: 0.11

95th Percentile 99th Percentile 99.9th Percentile

0.35 0.45 0.60

(0.45) (0.60) (--)

0.45 1.0 2.5

(0.80) (2.5) (--)

#REF!

0.60

0.35

0.9691

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