Bifenazate Summary of Analytical Chemistry and Residue Data DP#: D388800

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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF 

CHEMICAL SAFETY AND

POLLUTION PREVENTION

MEMORANDUM

Date: 15-May-2014

SUBJECT: Bifenazate. Section 3 Registration Request to Add New Uses on Timothy Forage 

and Hay; Herb, Subgroup 19A; and to Expand Existing Uses on Pome Fruit, 

Group 11, and Fruiting Vegetables, Group 8. Summary of Analytical 

Chemistry and Residue Data.

PC Code: 000586 DP Barcode: D388800

Decision No.: 446177 Registration Nos.: 400-503, 400-514

Petition No.: 1E7847 Regulatory Actions: Section 3 Registration

Risk Assessment Type: NA Case No.: 7609

TXR No.: NA CAS No.: 149877-41-8

MRID Nos.: 48560601, 47327701 40 CFR: §180.572

From: William D. Wassell, Chemist

Risk Assessment Branch 1 (RAB1)

Health Effects Division (HED, 7509P)

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

RAB1/HED (7509P)

To: William D. Wassell, Risk Assessor

RAB1/HED (7509P)

and

Barbara Madden , RM 05

Registration Division (RD; 7505P)

Executive Summary

Bifenazate (1-methylethyl 2-(4-methoxy[1,1’-biphenyl]-3-yl)hydrazinecarboxylate) is a selective 

miticide/insecticide which controls the motile stage of mites either by direct contact or through 

contact with foliar residues. There is conflicting evidence in the literature for bifenazate being a 

mitochondrial inhibitor or a GABA (gamma-aminobutyric acid) channel modulator. 

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

establishment of permanent tolerances for residues of the acaricide bifenazate and its metabolite 

D3598 [diazinecarboxylic acid, 2-(4-methoxy-[1,1’biphenyl]-3-yl, 1-methylethyl ester], 

(expressed as bifenazate) in/on the following raw agricultural commodities (RACs):
Bifenazate Summary of Analytical Chemistry and Residue Data DP#: D388800

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Commodity Proposed Tolerance

Herb Subgroup 19A, fresh leaves 30 ppm

Herb Subgroup 19A, dried leaves, 

except chervil, dried, and chive, dried

140 ppm

Fruit, Pome, Group 11-10 0.75 ppm

Vegetable, Fruiting, Group 8-10 2.0 ppm

Note: Bifenazate tolerances are established for residues in/on pome fruit (Group 11) and fruiting 

vegetables (Group 8) at the requested levels. IR-4 has proposed expanding the existing 

tolerances to cover additional commodities that are included in the revised crop Groups 11-10 

and 8-10. The petitioner further states that the established tolerances for residues in/on pome 

fruit, group 11; and fruiting vegetables, group 8 may be deleted upon establishment of the uses 

and tolerances for residues in/on pome fruit, group 11-10; and fruiting vegetables, group 8-10. 

Additionally, IR-4 proposes the establishment of tolerances with regional registrations for 

residues of bifenazate and its metabolite D3598 in/on the following RACs:

Commodity Proposed Tolerance

Timothy, forage 140 ppm

Timothy, hay 120 ppm

The end-use products (EPs) relevant to this registration request are Acramite®50WS (EPA Reg. 

No. 400-503), a 50% by weight wettable-powder (WP) in water-soluble bags (WSP), and 

Acramite®4SC (EPA Reg. No. 400-514), a 4 lb/gal suspension-concentrate (SC) formulation 

[equivalent to a flowable-concentrate (FlC) formulation].

IR-4 has proposed one foliar spray application to herbs and timothy by ground or aerial (timothy

only) equipment at a rate of 0.38 to 0.50 lb ai/A to herbs and 0.43 to 0.75 lb ai/A for timothy. 

The proposed pre-harvest intervals (PHIs) are 0 days for timothy forage, 7 days for timothy hay, 

and 3 days for herbs. The established use pattern for pome fruit and fruiting vegetables is one 

application using ground equipment at a maximum rate of 0.38 to 0.50 lb ai/A with PHIs of 3 

and 7 days for fruiting vegetables and pome fruit, respectively. Application by aerial equipment 

is permitted for fruiting vegetables. 

Tolerances are established (40 CFR §180.572(a)(1)) for residues of bifenazate and its metabolite 

D3598 (expressed as bifenazate) in/on various crops and livestock commodities (fat only). 

Additionally, tolerances are established (40 CFR §180.572(a)(2)) for residues of bifenazate and 

the metabolites D3598 (expressed as bifenazate), A1530 (1,1′-biphenyl, 4-ol) and A1530-sulfate 

(1,1′-biphenyl, 4-oxysulfonic acid) (expressed as 1,1′-biphenyl, 4-ol) (expressed as ,1′-biphenyl, 

4-ol) in milk and livestock tissues (excluding fat). Time-limited tolerances are established (40 

CFR §180.572(b)) for residues of bifenazate and D3598 in/on timothy forage at 50 ppm and 

timothy hay at 150 ppm. These tolerances will expire on 12/31/2016.

Additional plant metabolism data have not been submitted. The qualitative nature of the residue 

in plants is adequately understood based on acceptable studies with apple, orange, cotton, and 

radish. A briefing document, summarizing the studies (except the radish study) was presented to 

the Metabolism Assessment Review Committee (MARC). The MARC concluded that for 
Bifenazate Summary of Analytical Chemistry and Residue Data DP#: D388800

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tolerance expression and risk assessment purposes, the residues of concern in crops are 

bifenazate and its metabolite D3598 (calculated as the stoichiometric equivalent of bifenazate).

Additional livestock metabolism data have not been submitted. The nature of the residue in 

livestock is adequately understood based on studies with lactating goats and laying hens; 

however, livestock feedstuffs are not derived from the proposed crops of the subject petition with 

the exception of timothy. The proposed use on timothy is for a regional use in two counties of 

Nevada (Eureka and Humboldt Counties). Applications can only be made to timothy that is 

intended for use as horse feed. The use on timothy was discussed and approved by the 

ChemSAC (meeting of 1/12/2011). Thus, secondary residues of bifenazate in livestock tissues 

are not of concern for this petition.

The existing poultry metabolism study is adequate to allow HED to conclude that tolerances for 

poultry tissues and eggs are not needed for the purpose of this petition (Category 3 of 40 CFR 

§180.6). There is no reasonable expectation of finite residues in poultry matrices. This decision 

will be revisited in the future if additional crops with poultry feed stuffs are proposed for 

registration.

The qualitative nature of the residue in rotational crops is adequately understood based on an 

acceptable confined rotational metabolism study. The MARC reviewed the confined rotational 

crop study and concluded that the residues of concern in/on rotational crops could not be 

determined from the available data. The MARC concluded that a 30-day rotational crop 

restriction is appropriate based on the available data. Appropriate rotational crop restrictions 

appear on the product labels for Acramite®4SC and Acramite®50WS.

There are adequate residue analytical methods for tolerance enforcement. For plants, highperformance liquid chromatography with oxidative coulometric electrochemical detector 

(HPLC/ELCD) Method UCC-D2341 is available as a primary enforcement method for the 

combined residues of bifenazate and its metabolite D3598. The method has been forwarded to 

the Food and Drug Administration (FDA) for inclusion in the Pesticides Analytical Manual, 

Volume II (PAM II). The limit of quantification (LOQ) and limit of detection (LOD) of Method 

UCC-D2341 are 0.01 and 0.005 ppm, respectively. In addition, a liquid chromatographic system 

with tandem mass spectrometers (LC-MS/MS) method (NCL ME 245) was recently submitted as 

a confirmatory method and has been forwarded to FDA. 

The data-collection methods used for the analysis of samples taken from supporting magnitude 

of the residue studies are LC-MS/MS (basil) and HPLC/ELCD (timothy forage and hay). The 

LOQ for basil samples was 0.047 ppm for bifenazate and 0.048 ppm for D3598. The calculated 

LOD for bifenazate and D3598 in/on fresh basil samples were reported to be 0.0095 ppm and 

0.0082 ppm, respectively, and in/on dried basil as 0.012 ppm and 0.019 ppm, respectively. The 

lowest level method validation (LLMV) for residues in/on timothy was 0.01 ppm for bifenazate 

and D3598. Based on recoveries from timothy forage and hay samples fortified with bifenazate 

or D3598 at the LLMV, the estimated LODs were 0.004 ppm and 0.0042 ppm for bifenazate and 

D3598, respectively. The LOQ was 0.01 ppm for both compounds. 

The requirements for Multireresidue Methods (MRMs) testing data are fulfilled. Bifenazate and 

the metabolites D3598, A1530, and A1530-sulfate are not quantitatively recovered through the 

FDA MRMs.
Bifenazate Summary of Analytical Chemistry and Residue Data DP#: D388800

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Storage stability data are not required for the subject petition as all samples were extracted and 

analyzed within 30 days of harvest. The longest storage intervals were 14 days for basil samples 

and 22 days for timothy samples. 

IR-4 has submitted adequate field trial data for bifenazate on basil. Four field trials were 

conducted in the 2008 growing season. At each trial, basil was treated with a single foliar 

application of Acramite®50 WS, at the approximate rate of 0.75 lb ai/A (1.5x the proposed 

application rate). The fresh basil samples were collected at a PHI of 3 days. At one of the trials, 

additional samples were collected for drying. The maximum combined residues of bifenazate 

and D3598 in fresh basil were 15 ppm. The maximum combined residues of bifenazate and 

D3598 in dried basil was 91 ppm. For the trial that included dried basil, the maximum combined 

residues of bifenazate and D3598 were 9.5 ppm in fresh basil and 91 ppm in dried basil which 

represents a concentration factor of 9.6x for residues in dried basil. The residue data for basil 

from the submitted crop field trials were analyzed using the Organization for Economic Cooperation and Development (OECD) tolerance calculation procedures (see Appendix II). Based 

on the data set, the recommended tolerance for residues of bifenazate and D3598 (calculated as 

the stoichiometric equivalent of bifenazate) is 30 ppm in/on fresh herbs and 300 ppm in/on dried 

herbs.

IR-4 has submitted adequate field trial data for bifenazate on grasses. These data are intended to 

satisfy requirements for residue data for timothy forage and hay. Thirteen field trials were 

conducted in the United States during the 2004 growing season. At each trial, grasses received 

one foliar application of Acramite®4SC at a rate of approximately 0.75 lb ai/A. Grass forage 

samples were collected 4 hours after application and grass hay samples at 6 to 7 days after 

application. The maximum combined residues of bifenazate and D3598 in/on grass forage were 

83.5 ppm. The maximum combined residues of bifenazate and D3598 in/on grass hay in the 

submitted studies were 76.3 ppm. The residue data for grass forage and hay from the submitted 

crop field trials were analyzed using the OECD tolerance calculation procedures (see Appendix 

II). Based on the data set, the recommended tolerances for residues of bifenazate and D3598

(calculated as the stoichiometric equivalent of bifenazate) are 200 ppm in/on grass forage and 

150 ppm in grass hay.

Analytical reference standards for bifenazate and its metabolites D23-06 (D3598), D23-15, D23-

16 (A1530) and D23-19 (A1530) are currently available at the EPA National Pesticide Standards 

Repository (personal communication with Theresa Cole, Analytical Chemistry Branch (ACB), 

01/25/2012). However, the standard for metabolites D23-15 and D23-16 expire on 6/30/2012 

and 05/31/2012, respectively. Additionally, the Repository does not have standards for 

bifenazate metabolite D23-22. The registrant must either recertify the lots in the repository and 

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

previous lots will not be recertified.

Regulatory Recommendations and Residue Chemistry Deficiencies

HED has examined the residue chemistry database for bifenazate. Provided a revised Section F 

(see below) is submitted and the petitioner resolves the deficiency pertaining to the availability

of analytical-grade standards at the EPA National Pesticide Standards Repository (see below), 

there are no residue chemistry or toxicological data deficiencies that would preclude the 

establishment of permanent tolerances for residues of bifenazate and its metabolites as outlined 

in Table 2.2.2. A human-health risk assessment will be prepared as a separate document. 
Bifenazate Summary of Analytical Chemistry and Residue Data DP#: D388800

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The following residue chemistry data deficiencies must be fulfilled prior to granting the 

uses/tolerances. 

860.1550 Proposed Tolerances

In the subject petition, the proposed tolerance expression is in terms of the combined 

residues of bifenazate (1-methylethyl 2-(4-methoxy[1,1’-biphenyl]-3-

yl)hydrazinecarboxylate) and diazinecarboxylic acid, 2-(4-methoxy-[1,1’-biphenyl]-3-yl, 

1-methylethyl ester (expressed as bifenazate). The established tolerance expression for 

livestock commodities is in terms of the combined residues of bifenazate and 

diazinecarboxylic acid, 2-(4-methoxy-[1,1’biphenyl]-3-yl, 1-methylethyl ester (D3598, 

expressed as bifenazate), A1530 (1,1’-biphenyl, 4-ol) and A1530-sulfate (expressed as 

A1530; 1,1’biphenyl, 4-oxysulfonic acid). The proposed tolerance expressions need to 

be modified to comply with the interim guidance on tolerance expressions (Memo, 

5/27/2008, S. Knizner). 

The current tolerance expressions for bifenazate tolerances in 40 CFR §180.572(a)(1) and 

40 CFR §180.572(b) are as follows: 

Tolerances are established for residues of bifenazate (1-methylethyl 2-(4-methoxy[1,1'-

biphenyl]-3-yl)hydrazinecarboxylate) including its metabolites and degradates, in or on 

the commodities listed in the following table. Compliance with the tolerance levels 

specified are to be determined by measuring only the sum of bifenazate and its 

metabolite, diazinecarboxylic acid, 2-(4-methoxy-[1,1'-biphenyl]-3-yl), 1-methylethyl 

ester, (expressed as bifenazate) in or on the following food commodities:

The tolerance expression should be changed to conform to current HED policy. 

Specifically, the tolerance expression for 40 CFR §180.572(a)(1) should be as follows:

Tolerances are established for residues of the insecticide bifenazate (1-methylethyl 2-(4-

methoxy[1,1'-biphenyl]-3-yl)hydrazinecarboxylate) including its metabolites and 

degradates, in or on the commodities listed in the following table. Compliance with the 

tolerance levels specified are to be determined by measuring only the sum of bifenazate 

and its metabolite, diazinecarboxylic acid, 2-(4-methoxy-[1,1'-biphenyl]-3-yl), 1-

methylethyl ester, (calculated as the stoichiometric equivalent of bifenazate) in or on the 

following food commodities:

The current tolerance expressions for bifenazate tolerances in 40 CFR §180.572(a)(2) is 

as follows: 

Tolerances are established for residues of bifenazate (1-methylethyl 2-(4-methoxy[1,1′-

biphenyl]-3-yl) hydrazinecarboxylate) including its metabolites and degradates, in or on 

the commodities listed in the following table. Compliance with the tolerance levels 

specified are to be determined by measuring only the sum of bifenazate and its 

metabolites diazinecarboxylic acid, 2-(4-methoxy-[1,1′-biphenyl]-3-yl), 1-methylethyl 

ester (expressed as bifenazate); 1,1′-biphenyl, 4-ol; and 1,1′-biphenyl, 4-oxysulfonic acid 

(expressed as 1,1′-biphenyl, 4-ol) in or on the following food commodities:
Bifenazate Summary of Analytical Chemistry and Residue Data DP#: D388800

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The tolerance expression for 40 CFR §180.572(a)(2) should be modified as follows:

Tolerances are established for residues of the insecticide bifenazate (1-methylethyl 2-(4-

methoxy[1,1′-biphenyl]-3-yl) hydrazinecarboxylate) including its metabolites and 

degradates, in or on the commodities listed in the following table. Compliance with the 

tolerance levels specified are to be determined by measuring only the sum of bifenazate 

and its metabolites diazinecarboxylic acid, 2-(4-methoxy-[1,1′-biphenyl]-3-yl), 1-

methylethyl ester; 1,1′-biphenyl, 4-ol; and 1,1′-biphenyl, 4-oxysulfonic acid (calculated 

as the stoichiometric equivalent of bifenazate) in or on the following food commodities:

860.1650 Submittal of Analytical Reference Standards

Analytical reference standards for bifenazate and its metabolites D23-06 (D3598), D23-

15, D23-16 (A1530) and D23-19 (A1530) are currently available at the EPA National 

Pesticide Standards Repository (personal communication with Theresa Cole, Analytical 

Chemistry Branch (ACB), 01/25/2012). However, the standard for metabolites D23-15 

and D23-16 expired on 6/30/2012 and 05/31/2012, respectively. Additionally, the 

Repository does not have standards for bifenazate metabolite D23-22. The registrant 

must either recertify the lots in the repository and send in an updated certificate of 

analysis (COA), or submit new standards (different lot #) if the previous lots will not be 

recertified.

If new standards are being submitted, they should be sent to the Analytical Chemistry

Lab, which is located at Fort Meade, to the attention of either Theresa Cole 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.)

Background

The chemical structure and nomenclature of bifenazate and its metabolites are presented in Table 

1, and the physicochemical properties of the technical grade of bifenazate are presented in 

Table 2.
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Table 1. Test Compound Nomenclature.

Compound

Common name Bifenazate

Company experimental name D2341

IUPAC name isopropyl 3-(4-methoxybiphenyl-3-yl)carbazate or

isopropyl 2-(4-methoxybiphenyl-3-yl)hydrazinoformate

CAS name 1-methylethyl 2-(4-methoxy[1,1′-biphenyl]-3-yl)hydrazinecarboxylate

CAS registry number 149877-41-8

End-use products (EPs) Acramite®50WS (EPA Reg. No. 400-503)

Acramite®4SC ( EPA Reg. No. 400-514)

Compound

Common name None

Company experimental name D3598

IUPAC name isopropyl-(4-methoxy-[1,1’-biphenyl]-3-yl)diazenecarboxylate

CAS name diazenecarboxylic acid, 2-(4-methoxy-[1,1’-biphenyl]-3-yl), 1-methylethyl ester

CAS registry number 149878-40-8

Compound

OH

Common name None

Company experimental name A1530

IUPAC name 1,1’-biphenyl, 4-ol

CAS name p-hydroxybiphenyl

CAS registry number 92-69-3

Compound

OSO3H

Common name None

Company experimental name A1530 sulfate, biphenyl-4-ol-sulfate

IUPAC name Unknown

CAS name Unknown

CAS registry number Unknown

O

N

H

N

H

O CH3

O CH3

CH3

O

N

N O CH3

O CH3

CH3
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Table 2. Physicochemical Properties of the Technical Grade of Bifenazate.

Melting range 124-125oC

MRID 46064101

pH 6.78

Density 1.19 g/cm3

Water solubility 2.1 mg/L (20°C)

Solvent solubility 102 mg/mL ethyl acetate (20°C)

Vapor pressure <1 x 10-8

atm M3/mole (25°C)

Dissociation constant, pKa

12.94 at 23 C

Octanol/water partition coefficient, Log(KOW) 3.4

UV/visible absorption spectrum Max 264 nm in water

860.1200 Directions for Use

The proposed use directions are presented in Table 3 below. The information presented in Table 

3 was obtained from undated draft labels for Acramite®50WS (EPA Reg. No. 400-503) and 

Acramite®4SC (EPA Reg. No. 400-514).

Table 3. Summary of Proposed and Registered Directions for Use of Bifenazate.

Applic. 

Timing, 

Type, and 

Equip.

Formulation

[Reg. No.]

Applic. 

Rate 

(lb ai/A)

Max. No. 

Applic. per 

Season

Max. 

Seasonal 

Applic. Rate

(lb ai/A)

PHI

(days)

Use Directions and 

Limitations

Herb, Subgroup 19A (Except Dried Chervil and Dried Chive, Proposed Use)

Ground 

Application

Acramite®

50WS [400-503]

0.38 to 

0.50 1 0.50 (implied) 3

Application is to be 

made in a minimum of 

50 gal/A using ground 

equipment. For 

maximum control, 

applications must be 

made as soon as mites 

appear. 

Pome Fruit, Group 8-10 (Registered Use)

Ground 

Application 

Acramite®4SC

[400-514]

Acramite®

50WS [400-503]

0.38 to 

0.50 1 0.50 (implied) 7

Application is to be 

made in a minimum of 

50 gal/A using ground 

equipment. For 

maximum control, 

applications must be 

made as soon as mites 

appear. 

Fruiting Vegetables, Group 8-10 (Registered Use)

Ground 

Application

Acramite®4SC

[400-514]

Acramite®

50WS [400-503]

0.38 to 

0.50 1 0.50 (implied) 3

Application is to be 

made in a minimum of 

50 gal/A using ground 

equipment or 10 gal/A 

using aerial equipment. 

For maximum control, 

applications must be 

made as soon as mites 

appear. 

Timothy (Proposed Use)
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Table 3. Summary of Proposed and Registered Directions for Use of Bifenazate.

Applic. 

Timing, 

Type, and 

Equip.

Formulation

[Reg. No.]

Applic. 

Rate 

(lb ai/A)

Max. No. 

Applic. per 

Season

Max. 

Seasonal 

Applic. Rate

(lb ai/A)

PHI

(days)

Use Directions and 

Limitations

Ground or 

Aerial 

Application

Acramite®4SC

[400-514] 0.43 to 

0.75

1 0.75 (implied) 0 (forage)

7 (hay)

Application is to be 

made in a minimum of 

20 gal/A using ground 

equipment or 10 gal/A 

by air. For maximum 

control, applications 

must be made as soon as 

mites appear. 

The following rotational crop restriction is specified: “This product has a plantback restriction of 

30 days. Do not plant another crop within 30 days after last Acramite®application due to 

chances of bifenazate residues showing up in rotational crops.”

Conclusions: The proposed use directions are adequate to allow evaluation of the residue data 

relative to the proposed use.

860.1300 Nature of the Residue - Plants

Residue Chemistry Memo; DP# 324430, 7/19/06, T. Bloem (Discussion of Radish Metabolism Study).

Residue Chemistry Memo; DP# 276801, 8/16/01, T. Bloem (HED MARC Memo of Residues of Concern).

Residue Chemistry Memo; DP# 276623, 7/31/01, T. Bloem (MARC Briefing Document).

Residue Chemistry Memo; DP# 349556, 3/9/09, W.D. Wassell.

Additional plant metabolism data have not been submitted. The qualitative nature of the residue 

in plants is adequately understood based on acceptable studies with apple, orange, cotton, and 

radish. A briefing document, summarizing the salient features of these studies (except the radish 

study), was presented to the HED MARC. The MARC concluded that for tolerance expression 

and risk assessment purposes, the residues of concern in crops are bifenazate and its metabolite 

D3598 (calculated as the stoichiometric equivalent of bifenazate). 

The metabolic routes in all crops were similar with major residues being comprised of bifenazate 

and lesser amounts of D3598. The metabolic route in tested plants proceeded via oxidation of 

the hydrazine moiety of bifenazate to form D3598 which is further degraded and bound by 

reaction with natural products. The HED MARC discussed the possible formation of hydrazine 

in plants and concluded that formation of hydrazines is unlikely due to the oxidation of the 

parent to the conjugated diazene. The MARC suggested that if the petitioner submits additional 

metabolism studies, the presence of biphenyl hydrazine should be monitored as a confirmatory

measure.

Subsequent to the MARC decision, radish and corn metabolism studies were submitted. Radish 

plants were treated with single spray application of bifenazate at 0.375 or 0.75 lb ai/A, and 

mature root and top samples were harvested 7 days after application. No further analytical work 

was performed in/on the radish root samples since the total radioactive residues (TRRs) were 

<0.01 ppm. Analysis of the radish tops indicated that bifenazate and D3598 were the major 

residues. Hydroxylated D3598 and D2303 were also identified; biphenyl hydrazine was 

included as a reference standard but was not identified as a residue in the study. The corn 
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metabolism study was deemed unacceptable. The OPPTS Guidelines (860.1300) specify that if 

metabolism studies on three dissimilar crops show that the route of metabolism is similar then 

additional plant metabolism studies are not required. The bifenazate route of metabolism has 

been demonstrated to be similar in/on apple, orange, cotton, and radish. Additional plant 

metabolism data are not required for this petition.

860.1300 Nature of the Residue - Livestock

Residue Chemistry Memo; DP# 276801, 8/16/01, T. Bloem (HED MARC Memo of Residues of Concern).

ChemSAC Minutes of 01/12/11(Memo dated 01/27/11).

Additional livestock metabolism data have not been submitted. The nature of the residue in 

livestock is adequately understood based on studies with lactating goats and laying hens; 

however, livestock feedstuffs are not derived from the proposed crops of the subject petition with 

the exception of timothy. The proposed use on timothy is for a regional use in 2 counties of 

Nevada (Eureka and Humboldt Counties). Applications can only be made to timothy that is 

intended for use as horse feed. The use on timothy was discussed and approved by the 

ChemSAC (meeting of 1/12/11). Thus, secondary residues of bifenazate in livestock tissues are 

not of concern for this petition.

860.1340 Residue Analytical Methods

Plant Commodities

DER Reference: 47467702.der.doc (Includes MRID 47467704).

Residue Chemistry Memo; DP# 313261, 7/19/06, T. Bloem (Confirmatory enforcement method).

Residue Chemistry Memo; DP# 328814, 5/17/06, T. Bloem (Letter to FDA for inclusion of confirmatory 

enforcement method in PAM Volume II).

Residue Chemistry Memo; DP# 281973, 8/29/02, T. Bloem (Letter to FDA for inclusion of primary enforcement

method in PAM Volume II).

Residue Chemistry Memo; DP# 277089, 8/16/01, T. Bloem (Primary enforcement method).

Enforcement methods: There are adequate residue analytical methods for tolerance enforcement. 

For plants, the HPLC/ELCD Method UCC-D2341 is available as a primary enforcement method 

for the combined residues of bifenazate and its metabolite D3598. The method has been 

forwarded to the FDA for inclusion in the PAM II. The LOQ and LOD of Method UCC-D2341 

are 0.01 and 0.005 ppm, respectively. In addition, a LC-MS/MS method (NCL ME 245) was 

recently submitted as a confirmatory method and has been forwarded to FDA. 

Data-collection methods: The data-collection methods used for the analysis of samples taken 

from supporting magnitude of the residue studies are the LC/MS/MS method (NCL ME 245) 

(basil) and HPLC/ELCD Method UCC-D2341 (grass). 

Basil samples (fresh and dried) were extracted with acetonitrile containing 0.1% of glacial acetic 

acid. Residues in the samples were reacted with 3 mL of 0.25% ascorbic acid in 5:95 

acetonitrile: water and 45 μL of 10% acetic acid in water to convert D3598 into bifenazate. 

Total residues were determined by LC/MS/MS. 

The LOQ for residues in/on basil samples based upon the LLMV was 0.047 ppm for bifenazate 

and 0.048 ppm for D3598. The calculated LOD for bifenazate and D3598 in/on fresh basil 
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samples were reported to be 0.0095 ppm and 0.0082 ppm, respectively, and in/on dried basil as 

0.012 ppm and 0.019 ppm, respectively. 

Bifenazate and D3598 residues were extracted from homogenized timothy forage and hay by

blending twice with acetonitrile and acetic acid (0.1%) solution. The extracts were combined 

and filtered into a graduated cylinder and brought to a known final volume with acetonitrile. An 

aliquot of the sample extract was then partitioned with methylene chloride and 2% aqueous 

sodium sulfate. The methylene chloride phase from the partition was evaporated to near dryness 

and the extract was diluted with HPLC mobile phase. After an incubation period of at least 2 

hours in order to convert residues of D3598 to bifenazate, the samples were analyzed for residues 

by reverse phase HPLC/OCLD.

The LLMV for this study was 0.01 ppm for bifenazate and D3598. Based on recoveries from 

timothy forage and hay samples fortified with bifenazate or D3598 at the LLMV, the estimated 

LODs were 0.004 ppm and 0.0042 ppm for bifenazate and D3598, respectively. The LOQ was 

0.01 ppm for both compounds. 

Conclusions: There are adequate residue analytical methods for tolerance enforcement and data 

collection for plant commodities. 

860.1360 Multiresidue Methods

Residue Chemistry Memo; PP#5E6992; DP# 324430, 7/19/06, T. Bloem.

HED previously reviewed MRM data for bifenazate, D3598, A1530, and A1530-sulfate which 

were submitted to the FDA. These data indicate that bifenazate, D3598, A1530, and A1530-

sulfate are not quantitatively recovered through the FDA MRMs.

860.1380 Storage Stability

The storage durations and conditions of samples from the magnitude of the residue studies 

submitted to support this petition are presented in Table 4.

Table 4. Summary of Storage Conditions and Durations of Samples from Crop Filed Trials.

Matrix Storage Temperature Actual Storage 

Duration

Interval of Demonstrated Storage 

Stability

Basil Frozen at the field sites within 40 minutes 

of collection and stored at approximately 

<-20°C until sample preparation at the 

analytical laboratory.

14 days Not applicable.

Timothy At the field sites, samples were transferred 

to frozen storage within 3.5 hours of 

collection. Some samples were placed on 

dry ice immediately. Stored at 

approximately -19 to -28°C until sample 

preparation at the analytical laboratory.

22 days Not applicable.

Conclusions: Storage stability data are not required as all samples were extracted and analyzed 

within 30 days of harvest (longest interval: 22 days). 
Bifenazate Summary of Analytical Chemistry and Residue Data DP#: D388800

Page 12 of 22

860.1480 Meat, Milk, Poultry, and Eggs

Livestock feedstuffs are not derived from the proposed crops of the subject petition with the 

exception of timothy. The proposed use on timothy is for a regional use in 2 counties of Nevada 

(Eureka and Humboldt Counties). Applications can only be made to timothy that is intended for 

use as horse feed. The use on timothy was discussed and approved by the ChemSAC (meeting 

of 1/12/11). Thus, secondary residues of bifenazate in livestock tissues are not of concern for 

this petition.

860.1500 Crop Field Trials

Basil:

DER Reference: 48260601.der.doc.

The IR-4 has submitted field trial data for bifenazate on basil. Four field trials were conducted in 

the 2008 growing season, one in California (North American Free Trade Agreement (NAFTA 

Region 10), one in South Carolina (NAFTA Region 2), and two in Georgia (NAFTA Region 2). 

At each trial, basil was treated with a single foliar application of Acramite®50 WS, which 

contains 50% as the ai, at the approximate rate of 0.75 lb ai/A (1.5x). A commercially available 

adjuvant (non-ionic surfactant) was added to the spray mixture. The fresh basil samples were 

collected at a PHI of 3 days. At the 08-CA *85 trial, additional samples were collected for 

drying.

The analytical results show that after a total seasonal application rate of 0.75 lb ai/A at a 3-day

PHI, the maximum combined residues of bifenazate and D3598 in/on fresh basil were 15 ppm 

(08-GA *06). The maximum combined residues of bifenazate and D3598 in/on dried basil was 

91 ppm (08-CA *85) which represents a concentration factor of 9.89X for residues in dried basil. 

A summary of residue data for bifenazate in/on basil is presented in Table 5. 
Bifenazate Summary of Analytical Chemistry and Residue Data DP#: D388800

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TABLE 5. Summary of Residue Data from Crop Field Trials with Bifenazate.

Commodity

Total Applic. 

Rate2

(lb ai/A)

PHI

(days) 

Residue Levels (ppm)1

n Min. Max. HAFT3 Median Mean

Std. 

Dev.

Basil (fresh) 0.745 – 0.784 3 8 3.4 15 14.5 9.1 8.9 4.2

Basil (dried) 0.745 3 1 91 91 NA4 NA NA NA

1 These values represent the combined residues of bifenazate and D3598 reported as bifenazate equivalents. 

2 One foliar application of Acramite®

50WS at approximately 0.75 lb ai/A was made.

3 HAFT = highest average field trial.

4 NA = not applicable.

Conclusions: The submitted residue data are adequate to fulfill data requirements for basil, the 

representative crop for the herb subgroup 19A (fresh and dried). The number and locations of 

the crop field trials are adequate for a foliar use on herbs. The available data do support the 

proposed use pattern.

The residue data for basil from the submitted crop field trials were analyzed using the OECD 

tolerance calculation procedures (see Appendix II). Based on the data set, the recommended 

tolerance for residues of bifenazate and D3598 (calculated as the stoichiometric equivalent of 

bifenazate) is 30 ppm for residues in/on fresh basil.

For dried basil, the recommended tolerance for residues of bifenazate and D3598 (calculated as 

the stoichiometric equivalent of bifenazate) is 300 ppm (30 x 9.6 = 288, rounded up to 300) for 

residues in/on fresh basil.

Grass:

DER Reference: 47327701.der.doc.

IR-4 has submitted field trial data for bifenazate on grasses. These data are intended to satisfy

requirements for residue data for timothy forage and hay. Thirteen field trials were conducted in 

the United States encompassing NAFTA Zone 2: MD (2 trials), NC (1 trial), NJ (1 trial), and TN 

(1 trial); Zone 3: FL (2 trials); Zone 6: TX (1 trial); Zone 8: CO (1 trial); Zone 10: CA (1 trial); 

Zone 11: ID (1 trial) and WA (1 trial); and Zone 12: OR (1 trial) during the 2004 growing 

season. At each trial location, grasses received one foliar application of Acramite®4SC at a rate 

of approximately 0.75 lb ai/A. An adjuvant was added to the spray mixture for all applications. 

Grass forage samples were collected 4 hours after application and grass hay samples at 6 to 7 

days after application.

Maximum residues of bifenazate and D3598 in/on grass forage following a total application of 

approximately 0.75 lb ai/A and a PHI of 0 days was 83.5 ppm. The maximum residues of 

bifenazate and D3598 in/on grass hay following a total application of approximately 0.75 lb ai/A 

and a PHI of 7 days was 81.5 ppm. A summary of residue data for bifenazate in/on grass is 

presented in Table 6. 
Bifenazate Summary of Analytical Chemistry and Residue Data DP#: D388800

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TABLE6. Summary of Residue Data from Crop Field Trials with Bifenazate.

Commodity Total Applic. 

Rate (lb ai/A)

PHI 

(days)

Residue Levels1(ppm)

n Min. Max. HAFT2 Median Mean Std. Dev.

Grass Forage 0.72 to 0.77 0 12 27.0 83.5 83.5 53.5 53.5 19.4

Grass Hay 0.072 to 0.77 6 -7 10 14.1 76.3 76.3 31.9 39.3 20.0

1 Residues are reported as bifenazate equivalents.

2HAFT = highest average field trial.

Conclusions: The submitted residue data are adequate to fulfill data requirements for a regional 

use for bifenazate on Timothy that is used for horse feed only. The number and locations of the 

crop field trials are adequate for a regional use on timothy. The available data do support the 

proposed use pattern.

The residue data for grass forage and hay from the submitted crop field trials were analyzed 

using the OECD tolerance calculation procedures (see Appendix II). Based on the data set, the 

recommended tolerances for residues of bifenazate and D3598 are 200 ppm for residues in grass 

forage and 150 ppm for residues in grass hay.

Pome Fruit, Group 11-10:

No additional crop field trial data were submitted for bifenazate in/on pome fruits. A tolerance 

for residues of bifenazate and its metabolite in/on pome fruit, group 11-10 has been established 

at 0.75 ppm [40 CFR §180.572]. IR-4 has proposed to expand the use/tolerance to additional 

commodities included in the revised Group 11-10. The tolerance level should be established at 

the same level as that of Group 11. 

As the proposed use on the pome fruit, Group 11-10 is identical to the existing use on pome fruit, 

Group 11 on the product labels for Acramite®50WS (EPA Reg. No. 400-503) and Acramite®

4SC (EPA Reg. No. 400-514), the existing tolerance for residues in/on Group 11 can be 

translated to Group 11-10.

Fruiting Vegetables, Group 8-10;

No additional fruiting vegetables field trial data were submitted. A tolerance for residues of 

bifenazate and D3698 in/on fruiting vegetables, Group 8 has been established at 2.0 ppm [40 

CFR §180.572]. IR-4 has proposed to expand the use/tolerance to additional commodities 

included in the revised Group 8-10. The tolerance level should be established at the same level 

as that of Group 8. 

As the proposed use on the fruiting vegetables, Group 8-10 is identical to the existing use on 

Group 8 on the product labels for Acramite®50WS (EPA Reg. No. 400-503) and Acramite®4SC 

(EPA Reg. No. 400-514), the existing tolerance for residues in/on Group 8 can be translated to 

Group 8-10.

860.1650 Submittal of Analytical Reference Standards

Analytical reference standards for bifenazate and its metabolites D23-06, D23-15, D23-16 and 

D23-19 are currently available at the EPA National Pesticide Standards Repository (personal 
Bifenazate Summary of Analytical Chemistry and Residue Data DP#: D388800

Page 15 of 22

communication with Theresa Cole, Analytical Chemistry Branch (ACB), 01/25/2012). 

However, the standard for metabolites D23-15 and D23-16 expire in 6/30/2012 and 05/31/2012, 

respectively. Additionally, the Repository does not have standards for bifenazate metabolite 

D23-22. The registrant must either recertify the lots in the repository and send in an updated 

COA, or submit new standards (different lot #) if the previous lots will not be recertified.

If new standards are being submitted, they should be sent to the Analytical Chemistry Lab, 

which is located at Fort Meade, to the attention of either Theresa Cole 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 Confined Accumulation in Rotational Crops

Residue Chemistry Memo; DP# 324430, 7/19/06, T. Bloem.

Residue Chemistry Memo DP# 277089, 8/16/01, T. Bloem.

The qualitative nature of the residue in rotational crops is adequately understood based on an 

acceptable confined rotational metabolism study. The MARC reviewed the confined rotational 

crop study and concluded that the residues of concern in/on rotational crops could not be 

determined from the available data. The MARC concluded that a 30-day rotational crop 

restriction is appropriate based on the available data. The submitted labels have appropriate 

rotational crop restrictions of 30-days for all crops. 

860.1900 Field Accumulation in Rotational Crops

No field rotational crop data have been submitted. The following rotational crop restriction is 

specified for the Acramite®4SC product: “Do not plant another crop within 30 days after last 

Acramite®4SC application due to chances of bifenazate residues showing up in rotational 

crops.”

860.1550 Proposed Tolerances

In the subject petition, the proposed tolerance expression is in terms of the combined residues of 

bifenazate (1-methylethyl 2-(4-methoxy[1,1’-biphenyl]-3-yl)hydrazinecarboxylate) and 

diazinecarboxylic acid, 2-(4-methoxy-[1,1’-biphenyl]-3-yl, 1-methylethyl ester (expressed as 

bifenazate). The established tolerance expression for livestock commodities is in terms of the 

combined residues of bifenazate and diazinecarboxylic acid, 2-(4-methoxy-[1,1’biphenyl]-3-yl, 

1-methylethyl ester (D3598, expressed as bifenazate), A1530 (1,1’-biphenyl, 4-ol) and A1530-

sulfate (expressed as A1530; 1,1’biphenyl, 4-oxysulfonic acid). The proposed tolerance 

expressions need to be modified to comply with the interim guidance on tolerance expressions 

(Memo, 5/27/20089, S. Knizner). 

The current tolerance expressions for bifenazate tolerances in 40 CFR §180.572(a)(1) and 40 

CFR §180.572(b) are as follows: 
Bifenazate Summary of Analytical Chemistry and Residue Data DP#: D388800

Page 16 of 22

Tolerances are established for residues of bifenazate (1-methylethyl 2-(4-methoxy[1,1'-

biphenyl]-3-yl)hydrazinecarboxylate) including its metabolites and degradates, in or on the 

commodities listed in the following table. Compliance with the tolerance levels specified are to 

be determined by measuring only the sum of bifenazate and its metabolite, diazinecarboxylic 

acid, 2-(4-methoxy-[1,1'-biphenyl]-3-yl), 1-methylethyl ester, (expressed as bifenazate) in or on 

the following food commodities:

The tolerance expression should be changed to conform to current HED policy. Specifically, the 

tolerance expression for 40 CFR §180.572(a)(1) should be as follows:

Tolerances are established for residues of the insecticide bifenazate (1-methylethyl 2-(4-

methoxy[1,1'-biphenyl]-3-yl)hydrazinecarboxylate) including its metabolites and degradates, in 

or on the commodities listed in the following table. Compliance with the tolerance levels 

specified are to be determined by measuring only the sum of bifenazate and its metabolite, 

diazinecarboxylic acid, 2-(4-methoxy-[1,1'-biphenyl]-3-yl), 1-methylethyl ester, (calculated as 

the stoichiometric equivalent of bifenazate) in or on the following food commodities:

The current tolerance expressions for bifenazate tolerances in 40 CFR §180.572(a)(2) is as 

follows: 

Tolerances are established for residues of bifenazate (1-methylethyl 2-(4-methoxy[1,1′-

biphenyl]-3-yl) hydrazinecarboxylate) including its metabolites and degradates, in or on the 

commodities listed in the following table. Compliance with the tolerance levels specified are to 

be determined by measuring only the sum of bifenazate and its metabolites diazinecarboxylic 

acid, 2-(4-methoxy-[1,1′-biphenyl]-3-yl), 1-methylethyl ester (expressed as bifenazate); 1,1′-

biphenyl, 4-ol; and 1,1′-biphenyl, 4-oxysulfonic acid (expressed as 1,1′-biphenyl, 4-ol) in or on 

the following food commodities:

The tolerance expression for 40 CFR §180.572(a)(2) should be modified as follows:

Tolerances are established for residues of the insecticide bifenazate (1-methylethyl 2-(4-

methoxy[1,1′-biphenyl]-3-yl) hydrazinecarboxylate) including its metabolites and degradates, in 

or on the commodities listed in the following table. Compliance with the tolerance levels 

specified are to be determined by measuring only the sum of bifenazate and its metabolites 

diazinecarboxylic acid, 2-(4-methoxy-[1,1′-biphenyl]-3-yl), 1-methylethyl ester; 1,1′-biphenyl, 4-

ol; and 1,1′-biphenyl, 4-oxysulfonic acid (calculated as the stoichiometric equivalent of 

bifenazate) in or on the following food commodities:
Bifenazate Summary of Analytical Chemistry and Residue Data DP#: D388800

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Tolerance Summary for Bifenazate.

Commodity

Proposed 

Tolerance 

(ppm)

Recommended 

Tolerance 

(ppm)

Correct Commodity 

Definition/Comments

To be established under 40 CFR §180.572 (a) General. (1)

Herb, subgroup 19A, fresh leaves 30 30 Herb, subgroup 19A, fresh leaves, 

except chervil and chive

Herb, subgroup 19A, dried leaves, 

except chervil, dried and chive, 

dried

140 300

Timothy, forage 140 200 Tolerance with regional registrations

Timothy, hay 120 150 Tolerance with regional registrations

Fruit, pome, group 11-10 0.75 0.75

Vegetable, fruiting, group 8-10 2.0 4.0 Tolerance level for harmonization 

with PMRA

An International Residue Limit (IRL) Status Form is appended to this document. There are 

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

bifenazate in/on herbs, and timothy forage and hay. The tolerance expression for plant 

commodities are harmonized between the U. S. and Canada, but not with Codex. Canadian 

MRLs are established for residues in/on apples, bell peppers and tomatoes, but not for other 

crops in the pome fruit and fruiting vegetables crop groups. The Canadian MRLs for residues in 

apples, bell peppers and tomatoes are not harmonized with the U. S. tolerance levels for residues 

in pome fruits and fruiting vegetables. Codex MRLs are established for pome fruits, peppers and 

tomato, but not for the other members of the fruiting vegetables crop group. Additionally the 

Codex MRLs for residues in pome fruits, peppers, and tomato are not harmonized with the U.S. 

tolerance levels.

Attachments:

1. Chemical Structures

2. Tolerance-Assessment Calculations.

3. International Residue Limit Status Sheet

RDI: RAB1 (09/19/2012)

W. Wassell: S-10958: Potomac Yard 1 (PY1): (703)305-6135): 7509P: RAB1
Bifenazate Summary of Analytical Chemistry and Residue Data DP#: D388800

Page 18 of 22

Attachment 1: Chemical Structures

Chemical Name Chemical Structure 

bifenazate (D2341)

hydrazinecarboxylic acid, 2-(4-methoxy-[1,1’-biphenyl]-3-yl), 1-

methylethyl ester

D3598

diazinecarboxylic acid, 2-(4-methoxy-[1,1’-biphenyl]-3-yl), 1-

methylethyl ester

D4642

diazinecarboxylic acid, 2-(4-methoxy-[1,1’-biphenyl]-3-yl), 1-

methylethyl ester 2-oxide

OCH3

N

N O CH3

OH O CH3

D9963

4-methoxy-[1,1’-biphenyl]-3-ol

OCH3

OH

D1989

1,1’-biphenyl, 4-methoxy

OCH3

D9569

[1,1’-biphenyl]-4,4’-diol

HO OH

A1530

1,1’-biphenyl, 4-ol

OH

A1530-sulfate

OSO3H

D9472

OH

OH

D23-14; 

biphenyl hydrazine;

(4-methoxy-[1,1’-biphenyl]-3-yl)hydrazine

OCH3

NH NH2

O

N

H

N

H

O CH3

O CH3

CH3

O

N

N O CH3

O CH3

CH3
Bifenazate Summary of Analytical Chemistry and Residue Data DP#: D388800

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Attachment 2. Tolerance-Assessment Calculations.

Bifenazate

Basil

USA

0.75 lb ai/A

Total number of data (n) 4

Percentage of censored data 0%

Number of non-censored data 4

Lowest residue 3.450

Highest residue 14.500

Median residue 8.875

Mean 8.925

Standard deviation (SD) 4.540

Correction factor for censoring (CF) 1.000

Proposed MRL estimate

- Highest residue 14.500

- Mean + 4 SD 27.086

- CF x 3 Mean 26.775

Unrounded MRL 27.086

Rounded MRL 30

High uncertainty of MRL estimate.

[Small dataset]

Residues (mg/kg) n

3.45 1

8.25 1

9.5 1

14.5 1
Bifenazate Summary of Analytical Chemistry and Residue Data DP#: D388800

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Bifenazate

grass forage

USA

0.75 lb ai/A

Total number of data (n) 12

Percentage of censored data 0%

Number of non-censored data 12

Lowest residue 27.000

Highest residue 83.500

Median residue 53.450

Mean 53.533

Standard deviation (SD) 19.423

Correction factor for censoring (CF) 1.000

Proposed MRL estimate

- Highest residue 83.500

- Mean + 4 SD 131.224

- CF x 3 Mean 160.600

Unrounded MRL 160.600

Rounded MRL 200

Residues (mg/kg) n

27 1

28.6 1

34.1 1

35.7 1

48.2 1

52.6 1

54.3 1

58.9 1

70.5 1

73 1

76 1

83.5 1
Bifenazate Summary of Analytical Chemistry and Residue Data DP#: D388800

Page 21 of 22

Bifenazate

grass hay

USA

0.75 lb ai/A

Total number of data (n) 10

Percentage of censored data 0%

Number of non-censored data 10

Lowest residue 14.100

Highest residue 76.300

Median residue 31.900

Mean 39.324

Standard deviation (SD) 19.980

Correction factor for censoring (CF) 1.000

Proposed MRL estimate

- Highest residue 76.300

- Mean + 4 SD 119.245

- CF x 3 Mean 117.972

Unrounded MRL 119.245

Rounded MRL 150

Residues (mg/kg) n

14.1 1

19.6 1

25.9 1

28.24 1

31.2 1

32.6 1

51.6 1

53.6 1

60.1 1

76.3 1
Bifenazate Summary of Analytical Chemistry and Residue Data DP#: D388800

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Attachment 3: International Residue Limit Status Sheets

Bifenazate (000586; 09/05/2012)

Summary of US and International Tolerances and Maximum Residue Limits 

Residue Definition:

US Canada Mexico2 Codex3

40 CFR 180.572: 

Plant/Livestock fat: Sum of 

Bifenazate (1-methylethyl 2-(4-

methoxy[1,1'-biphenyl]-3-

yl)hydrazinecarboxylate) and its 

metabolite diazinecarboxylic 

acid, 2-(4-methoxy-[1,1'-

biphenyl]-3-yl), 1-methylethyl 

ester (D3598) (expressed as 

bifenazate) 

Livestock (except fat): sum of 

bifenazate and its metabolites 

D3598 (expressed as bifenazate); 

1,1′-biphenyl, 4-ol; and 1,1′-

biphenyl, 4-oxysulfonic acid 

(expressed as 1,1′-biphenyl, 4-ol) 

Plant/Livestock fat: 1-methylethyl 

2-(4-methoxy[1,1'-biphenyl]-3-yl)

hydrazinecarboxylate, including the 

metabolite

diazenecarboxylic acid, 2-(4-

methoxy-[1,1'-biphenyl]-

3-yl),1-methylethyl ester

Livestock except fat: 1-methylethyl 

2-(4-methoxy[1,1'-biphenyl]-3-

yl)hydrazinecarboxylate, including 

the metabolites diazenecarboxylic 

acid, 2-(4-methoxy-[1,1'-biphenyl]-

3-yl), 1-methylethyl ester and [1,1'-

biphenyl]-4-ol and [1,1'-biphenyl]-

4-ol sulfate

Sum of Bifenazate 

and 

bifenazatediazene, 

diazinecarboxylic 

acid, 2-(4-

methoxy-[1,1'-

biphenyl]-3-yl), 1-

methylethyl ester 

(expressed as 

bifenazate) 

Bifenazate is a fat 

soluble compound.

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

US Canada Mexico2 Codex3

Fruit, pome, group 11 0.75 0.6 apples 0.7 pome fruits

Vegetable, fruiting, group 8

2.0

1.1 bell peppers

0.35 tomatoes

3 peppers chili

Peppers, sweet 

including (pimento 

or pimiento)

0.5 tomato

Herb subgroup 19A, fresh leaves 30 40 mints

Herb subgroup 19A, dried leaves 

except chervil, dried and chive, 

dried.

140

Timothy, forage 140

Timothy, Hay 120

Completed: M. Negussie; 09/10/2012

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.