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`

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF

CHEMICAL SAFETY AND

POLLUTION PREVENTION

MEMORANDUM

Date: May 25, 2012

SUBJECT: Bifenthrin. Section 3 Registration for Grass Grown for Seed and Imported Tea; Section 

18 Emergency Exemption for Apples, Nectarines, and Peaches. Summary of 

Analytical Chemistry and Residue Data. 

PC Code: 128825 DP Barcode: 388604

Decision No.: NA Registration No.: 279-3313, 279-3108

Petition No.: 9E7652 Regulatory Action: New Use Registration

Risk Assessment Type: NA Case No.: NA

TXR No.: NA CAS No.: 82657-04-3

MRID No.: Summary Table Provided Below 40 CFR: 180.442

FROM: Peter Savoia, Chemist

Risk Assessment Branch V/VII

Health Effects Division (7509P)

THRU: Michael S. Metzger, Branch Chief

William H. Donovan, Ph.D., Chemist

Risk Assessment Branch V/VII

Health Effects Division (7509P)

TO: Laura E. Nollen, Biologist

Risk Integration, Minor Use & Emergency Response Branch 

Registration Division (7505P)

MRID Summary Table

MRID No. Study Type Comments

47920801 860.1500 (Grass, seed crop) 47920801.der.doc

47920802 860.1500 (Tea) 47920802.der.doc

47920803 860.1500 (Tea) 47920803.der.doc

47920804-07 and -09 860.1500 (Tea) None

47920808 860.1500 (Tea) 47920808.der.doc

47920810 860.1500 (Tea) 47920810.der.doc

The Memorandum was prepared by Versar and has been reviewed by the Health Effects Division 

(HED) and revised as needed for correctness, language and to reflect current Office of Pesticide 

Programs (OPP) policies.
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

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Executive Summary

Bifenthrin, (2-methyl[1,1’-biphenyl]-3-yl) methyl-3-(2-chloro-3,3,3,-trifluoro-1-propenyl)-2,2-

dimethylcyclopropanecarboxylate, is a broad-spectrum non-systemic insecticide/miticide. 

Registered to FMC Corporation, this synthetic pyrethroid carries uses for foliar applications on a 

variety of field, fruit, and vegetable crops. Permanent tolerances are established for residues of 

bifenthrin in/on a number of food commodities listed under 40 CFR §180.442(a)(1). These 

tolerances range from 0.05 ppm on various crop and poultry commodities up to 70 ppm for grain, 

aspirated fractions. A tolerance of 0.05 ppm is also listed under §180.442(a)(2) for bifenthrin in 

food/feed handling establishments. In addition, time-limited tolerances for orchardgrass forage and

hay were established under §180.442(b) following Section 18 emergency exemptions with a 12/31/12

expiration date.

In the current petition, the Interregional Research Project No. 4 (IR-4) requests Section 3 registration 

for the application of bifenthrin to grass grown for seed on behalf of the Agricultural Experiment 

Station of Oregon. For this action (PP#9E7652), IR-4 has also included data to support the 

establishment of a permanent tolerance in/on imported tea which is being requested on behalf of the 

tea industry. In a separate petition, Delaware, Maryland, New Jersey, North Carolina, Pennsylvania, 

Virginia, and West Virginia is requesting an emergency exemption for treating apples, nectarines, and 

peaches. The establishment of permanent tolerances is therefore requested in/on grass forage, grass 

hay, and tea along with time limited emergency exemptions to be set for apples, nectarines, and 

peaches at the following limits:

Apple.............................................................................0.5 ppm

Grass, forage .................................................................2.5 ppm

Grass, hay .....................................................................4.5 ppm

Nectarine .......................................................................0.5 ppm

Peach.............................................................................0.5 ppm

Tea, plucked leaves........................................................25 ppm

The nature of bifenthrin residues in plants and livestock is understood based on the previouslysubmitted apple, corn, cotton, potato, hen, and goat metabolism studies. Based upon these studies, 

the Metabolism Committee determined that only the parent compound would be the relevant residue 

of concern for tolerance enforcement and risk assessment (Metabolism Committee Meeting Minutes, 

M. T. Flood, 07/27/1993). Further, the nature of the residues in rotational crops is adequately

understood. Based on a confined rotational crop study, HED has concluded that the residue of 

concern in rotational crops is the parent compound only. For annual crops evaluated at a maximum 

seasonal use rate of 0.5 lb ai/A, the confined study and the available field rotational crop study on 

wheat support the current rotational crop restrictions on the labels. Crops having bifenthrin 

tolerances may be replanted at any time, and all other crops may be replanted 30 days following the 

last application of bifenthrin. No rotational crop tolerances are required.

Adequate Gas Chromatography/Electron-Capture Detection (GC/ECD) methods are available for 

enforcing tolerances of bifenthrin in plant and livestock commodities. The MRM methods are also 

adequate for the enforcement of bifenthrin tolerances and no additional data are required. Analytical 

standards for bifenthrin furnished by FMC Agricultural Products are currently available in the EPA 

National Pesticide Standards Repository (personal communication with Theresa Cole, 04/26/2012). 

Samples from the current grass field trials were analyzed for residues of bifenthrin using FMC 

method PC-2132M, which is a modification to one of the current enforcement methods (P-2550 M). 
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

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The method reports the Limit of Detection (LOD) to be 0.01 ppm for grass forage and 0.03 ppm for 

grass hay. It further notes the Limit of Quantitation (LOQ) to be 0.03 ppm in grass forage and 0.08 

ppm in grass hay. The method was adequately validated in conjunction with the analysis of samples 

from the field trials. Similarly, the samples from the tea field trials in MRID No. 47920803 were 

analyzed for residues of bifenthrin using a GC/ECD method. The method was successfully validated 

prior to analysis of the field samples. The method LOD for bifenthrin in tea was reported to be 0.05 

ppm and the LOQ was not provided.

The submitted residue data for grass grown for seed are adequate, and the trials conducted reflect the 

proposed treatment pattern which will be established for use to crops grown only in ID, OR and WA. 

They were carried out following the EPA memo entitled “Additional Guidance on the Crop – ‘Grass 

Grown for Seed’” dated 9/30/2000 which requires the collection of forage and hay data. In practice, 

the forage and hay commodities of grass are used as a livestock feedstuff commonly fed to cattle. 

Based upon this assessment, HED concludes that the established bifenthrin livestock tolerances 

remain appropriate.

In support of tea, the petitioner provided nine (9) data submissions depicting residue levels for this 

imported Raw Agricultural Commodity (RAC). The majority of these studies are incomplete failing 

to note experimental field parameters (application rates, PHIs, sample handling procedures), storage 

duration and conditions, raw data, and concurrent recoveries. Due to the incompleteness of these 

submissions, Data Evaluation Records (DERs) could only be completed for four of the nine studies. 

In all, only MRID No. 47920803 is considered to be scientifically acceptable though it was found to 

lack concurrent recovery information. Residues in these fresh leaf and black tea samples were 

analyzed by Gas-Liquid Chromatography/Electron Capture Detection (GLC/ECD). The method was 

successfully validated as shown by recoveries of fortified samples but no data from concurrent 

recovery samples were provided. The application rate used in this study (0.060 kg ai/ha) is less than 

GAP application rate of 0.080 kg ai/ha. 

To support the establishment of a time limited emergency exemption for apples, nectarines, and 

peaches, adequate pear data are available for translation to the requested crops. For pears, use of WP 

(EPA Reg. No. 279-3108) and EC (EPA Reg. No. 279-3069) formulations have been established. 

The application pattern prescribes a seasonal rate of 0.5 lbs.ai/A (0.45 lbs ai/A post-bloom) made as 

multiple treatments at a 30-day Re-Treatment Interval (RTI) prior to a 14-day Pre-Harvest Interval 

(PHI). This use pattern resulted in a 0.5 ppm tolerance (DP. Nos. D274839 & D280288, S. Levy, 

08/15/2002). Thus, this level may be translated to apples, nectarines, and peaches.

There are adequate storage stability data to validate the storage conditions and durations of RACs 

collected from the grass field trials. These data indicate that residues decline by 35% in forage and 

55% in hay, requiring the correction of residues from the grass field trial data. For imported tea, no 

storage stability data were provided, however, the longest storage interval was only 67 days in the 

trials from India. In addition to the storage stability data on grass, previously submitted data indicate 

that bifenthrin residues are stable when stored frozen for 12 months in corn flour, 36 months in 

lettuce, pecans and potatoes along with durations up to 49 months in apple (DP Nos. D274839 & 

D280288, S. J. Levy, 08/15/2002). 
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

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Regulatory Recommendations and Residue Chemistry Deficiencies

Pending revision of Sections B and F, there are no residue chemistry deficiencies that would preclude 

granting a regional registration of bifenthrin for use on grass grown for seed and the establishment of 

a tolerance on imported tea. There are also adequate data to support a time limited emergency

exemption for apples, nectarines, and peaches. Tolerances are established for residues of bifenthrin, 

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

tolerance levels specified below is to be determined by measuring only bifenthrin, (2-methyl[1,1′-

biphenyl]-3-yl)methyl (1R,3R)-rel-3-[(1Z)-2-chloro-3,3,3-trifluoro-1-propenyl]-2,2-

dimethylcyclopropanecarboxylate in or on the commodity:

(a) General. 

Tea, dried ......................................................................30 ppm

(b) Section 18 emergency exemptions. 

Apple.............................................................................0.5 ppm

Nectarine .......................................................................0.5 ppm

Peach.............................................................................0.5 ppm

(c) Tolerances with regional registrations.

Grass, forage .................................................................4.0 ppm

Grass, hay.......................................................................15 ppm

A new human health risk assessment which includes these new crop uses and the amended tolerance 

levels for the pertinent livestock commodities is forthcoming in a separate document.

860.1200 Directions for Use

An amended Section B is required for grass grown for seed by noting this use is restricted to ID, OR, 

and WA on product labels 279-3108 and 279-3313. The grass crop group should be removed from 

the proposed product labels since the data provided only support the use of bifenthrin on grass grown 

for seed in the Pacific Northwest. 

Sufficient information was provided on the Good Agricultural Practices (GAP) followed for the 

cultivation of tea in India. The data are adequate to establish a tolerance for bifenthrin on imported 

tea. 

Application directions for treating apples, nectarines, and peaches as an emergency exemption in the 

states of Delaware, Maryland, New Jersey, North Carolina, Pennsylvania, Virginia, and West 

Virginia must be provided. Amended product labels for the 10% WP (EPA Reg. No. 279-3108) and

2 lb/gal EC (EPA Reg. No. 279-3069) formulations of bifenthrin are needed.

860.1550 Proposed Tolerances

The registrant is required to submit a revised Section F to amend all the proposed tolerances relevant 

to this petition and to reflect correct commodity definition as reflected in Table 10.
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

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International Harmonization

There are no Maximum Residue Limits (MRLs) established by Codex, Canada, or Mexico for any of

the proposed commodities in the current registration action (see Attachment 1). However, Codex has 

proposed a 30 ppm MRL for Tea, Green and Black (black, fermented and dried). In order to 

harmonize with the Codex MRL, a U.S. tolerance level of 30 ppm is recommended for tea, dried. 

Background

Bifenthrin is a broad-spectrum, non-systemic insecticide/miticide classified as a synthetic pyrethroid. 

Like many other insecticides, bifenthrin controls insects by paralyzing the central nervous system 

upon contact and ingestion. Applications of bifenthrin are made at the labeled use rates when insect 

populations reach locally determined economic thresholds. Follow-up treatments should be made as 

needed to control insect populations for the purposes of forming a comprehensive integrated pest 

management program. Registered to FMC Corporation, permanent tolerances are established for 

residues of bifenthrin in/on several food commodities listed under 40 CFR §180.442(a)(1). These 

tolerances range from 0.05 ppm on various crop and poultry commodities up to 70 ppm for grain, 

aspirated fractions. A tolerance of 0.05 ppm is also listed under §180.442(a)(2) for bifenthrin in 

food/feed handling establishments. In addition, time-limited tolerances for orchardgrass forage and 

hay were established under §180.442(b) following Section 18 emergency exemptions with a 12/31/12

expiration date. The nomenclature and physiochemical properties of bifenthrin are presented below 

in Tables 1 and 2 for review. 

Table 1. Bifenthrin Nomenclature.

Chemical structure

Common name Bifenthrin

Company experimental name FMC 54800

IUPAC name 2-methylbiphenyl-3-ylmethyl (1RS,3RS)-3-[(Z)-2-chloro-3,3,3-trifluoroprop-1-

enyl]-2,2-dimethylcyclopropanecarboxylate

or

2-methylbiphenyl-3-ylmethyl (1RS)-cis-3-[(Z)-2-chloro-3,3,3-trifluoroprop-1-

enyl]-2,2-dimethylcyclopropanecarboxylate

CAS name (2-methyl[1,1′-biphenyl]-3-yl)methyl (1R,3R)-rel-3-[(1Z)-2-chloro-3,3,3-

trifluoro-1-propenyl]-2,2-dimethylcyclopropanecarboxylate

CAS registry number 82657-04-03

End-use product (EP) 2.0 lb ai/gal emulsifiable-concentrate formulation (Capture® 2EC; EPA Reg. No. 

279-3069 and Brigade® 2EC; EPA Reg. No. 279-3313)

10% wettable-powder formulation (Brigade® WSB, EPA Reg. No. 279-3108)

O

O

F Cl 3C

CH3

H3C CH3
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

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Table 2. Physicochemical Properties of Bifenthrin.

Parameter Value Reference

Melting range 68-70.6°C Product Chemistry Chapter of the 

Bifenthrin Tolerance Reassessment 

Eligibility Decision (TRED), (DP No.

283808, 8/21/02, S. Levy)

pH NA1

Density 1.26 g/mL

Water solubility <0.1 μg/L

Solvent solubility 8.9 in heptane and methanol

125 in acetone, chloroform, ether, 

methylene chloride, and toluene 

Vapor pressure 2.41 x 10-5

Dissociation constant, pKa Not applicable

Octanol/water partition coefficient, 

Log(KOW) >1 x 10 6

UV/visible absorption spectrum NA

1 NA = information not available.

860.1200 Directions for Use

Grass (grown for seed)

IR-4 submitted proposed supplemental labels for Brigade WSB Insecticide/Miticide (EPA Reg. No.: 

279-3108) and Brigade 2EC Insecticide/Miticide (EPA Reg. No.: 279-3313). The petitioner also 

states that the label for Capture 2 EC Insecticide/Miticide (EPA Reg No.: 279-3069) supports this 

tolerance petition, but this label was not provided. The proposed grass use pattern is detailed below 

in Table 3 which allows two 0.1 lb ai/A treatments to be made for a maximum seasonal rate of 0.2 lb 

ai/A as appropriately demonstrated by the field trials supporting this petition.

Table 3. Summary of Directions for Use of Bifenthrin on Grass.

Commodity Trade Name (EPA 

Reg. No.)

Application 

Timing, 

Type, and 

Equipment

Maximum 

Application 

Rate (lb 

ai/A)

Maximum 

Number 

Applications 

per Season

Maximum Total 

Seasonal 

Application Rate

(lb ai/A)

PHI

(days)

Use Directions 

and Limitations

PP# 9F7602

Grass grown 

for seed

Brigade WSB 

Insecticide/Miticide 

(279-3108)

Ground and

aerial

0.1 Two (2) 0.2 30 days 

for 

forage 

and hay

RTI: 14 days. 

Min. spray 

volume: 10 GPA

ground, 2 GPA 

aerial.

Brigade 2EC 

Insecticide/Miticide 

(279-3313)

Ground and

aerial

Not reported Not reported 0.2 30 days 

for 

forage 

and hay

RTI: 14 days. 

Min. spray 

volume: 10 GPA

ground, 2 GPA 

aerial.

Tea

GAP information was provided for the products Talstar 8SC and Brigade 8 SC for use on tea grown 

in India. Talstar 8SC is an 80 g ai/L SC formulation of bifenthrin. One foliar application is made to 

tea using a spray volume of 400 L/ha and a 7-day PHI. The application rate was not provided. For 

Brigade 8 SC, an 80 g ai/L SC formulation, one foliar application is made at 0.08 kg ai/ha (0.07 lb 

ai/A) using a spray volume of 400 L/ha which specifies a PHI of 7 days.
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

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Apples, nectarines, and peaches

The bifenthrin products relevant for carrying this use as a time limited emergency exemption are the 

10% WP (EPA Reg. No. 279-3108) and the 2 lb/gal EC (EPA Reg. No. 279-3069) formulations. 

These end use products were examined through studies made in treating pears at the seasonal rate of 

0.5 lbs.ai/A (0.45 lbs ai/A post-bloom) following a 14 day PHI. This envisioned pattern of use based 

upon the pear data obtained is delineated below in Table 4 for review.

Table 4. Summary of Directions for Use of Bifenthrin on Pears to be used for treating Apples, Nectarines, and Peaches.

Commodity Trade Name (EPA 

Reg. No.)

Application 

Timing, 

Type, and 

Equipment

Application 

Rate (lb 

ai/A)

Maximum 

Number 

Applications 

per Season

Maximum 

Seasonal 

Application Rate

(lb ai/A)

PHI

(days)

Use Directions and 

Limitations

Section 18 Emergency Exemption

Apples, 

Nectarines & 

Peaches

Brigade WSB 

Insecticide/Miticide 

(279-3108)

Ground and

aerial

0.04 - 0.2 Not Reported 0.5 14

days 

RTI: 30 days. Min. 

spray vol.: 200 GPA.

Apply no more than 

0.45 lbs ai/A after 

petal fall

Capture 2EC 

Insecticide/Miticide 

(279-3069)

Ground and

aerial

0.04 – 0.2 Not Reported 0.5 14

days 

RTI: 30 days. Min. 

spray vol.: 200 GPA.

Apply no more than 

0.45 lbs ai/A after 

petal fall

Conclusions: A revised Section B is needed specifying all applicable directions for the proposed new 

uses of bifenthrin. For grass, label 279-3108 is adequate to allow evaluation of the residue data 

relative to this intended new use. The field trial data provided appropriately reflect the proposed use 

pattern in supporting two (2) applications made at 0.1 lb ai/A with an RTI of 14-days for a seasonal 

total of 0.2 lb ai/A. However, product label 279-3313 is inadequate due to the fact that the 

application rate is not specified. Additionally, both labels are to include that this proposed use carries 

a regional restriction for only the Pacific Northwest States of Oregon, Washington, and Idaho. The 

data provided for this petition only support treating grass grown for seed in the Pacific Northwest. 

The proposed labels inappropriately indicate that the products can be used on “Grass Forage, Fodder, 

and Hay Group and Grass Grown for Seed, Pasture and Rangeland.” This listing should be replaced 

with “Grass Grown for Seed.” For imported tea, GAP information on its cultivation in India was 

appropriately provided so that the data furnished could be evaluated for establishing a tolerance on 

this commodity. For treating apples, nectarines, and peaches carried as an emergency exemption in 

the states of Delaware, Maryland, New Jersey, North Carolina, Pennsylvania, Virginia, and West 

Virginia application directions must be provided. Amended product labels for the 10% WP (EPA 

Reg. No. 279-3108) and 2 lb/gal EC (EPA Reg. No. 279-3069) formulations of bifenthrin are needed.

860.1300 Nature of the Residue – Plants and Livestock

Bifenthrin TRED; DP No. 283808, 8/21/02, S. Levy

Adequate studies are available depicting the relevant residues of concern for bifenthrin tolerance 

enforcement and risk assessment. As such, adequate metabolism studies made on apples, corn, and 

cotton were previously reviewed in conjunction with earlier bifenthrin petitions (PP#5G3201, 

PP#6F3453 & PP#7F3546). Based upon these studies, the Metabolism Committee determined that 

only the parent compound would be the relevant residue of concern to be established for the tolerance 
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

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enforcement and risk assessment of crops (Metabolism Committee Meeting Minutes, M. T. Flood, 

07/27/1993). 

Adequate ruminant and poultry metabolism studies were likewise reviewed in conjunction with 

earlier bifenthrin petitions (PP#5G3201 & PP#6F3453). Based upon these studies, the Metabolism 

Committee subsequently determined that bifenthrin per se would be the relevant residue of concern 

established for the tolerance enforcement and risk assessment of livestock (Metabolism Committee 

Meeting Minutes, M. T. Flood, 07/27/1993). 

Conclusions. For the purposes of this action, the available metabolism data will also support the enduse product labeling request for grass and tea, as well as apple, nectarine, and peach. 

860.1340 Residue Analytical Methods

Bifenthrin TRED; DP No. 283808, S. Levy, 08/21/2002

DER for MRID 47920801, S. Tadayon, 03/22/2010

DER for MRID 47920803, P. Savoia, 09/XX/2010 

ACB Tolerance Enforcement Method Review; DP No. D384283, C. J. Stafford, 12/22/2010 

Enforcement Methods 

The registrant has developed adequate tolerance enforcement methods which rely on GC/ECD 

analyses for determining bifenthrin residues in both plant and livestock commodities. The available 

method for plant commodities works by performing the extraction of the sample with acetone, 

partitioning with hexane, purification using a Florisil column, and analysis of residues by GC/ECD. 

A modified version of the protocol for tree nuts has been provided which enables it to determine 

bifenthrin residues in walnut nutmeat. It was initially concluded that the supporting validation data 

provided with the revised GC/ECD tree nut procedure are adequate but a rewritten version of the 

method should be provided by the registrant. Final review by ACB notes that the revised tree nut 

enforcement method meets OPPTS 860.1340 test guidelines and rewriting the protocol is no longer 

considered necessary (DP No. D384283, C. J. Stafford, 12/22/2010).

For ruminant commodities, an established method is available to perform these analyses. FMC 

method P-1031 is another GC/ECD procedure which has been developed by the registrant and proven 

to be adequate for enforcing bifenthrin tolerances in milk and ruminant tissues. The reported LOQ 

for these methods is 0.05 ppm and in some cases sample extracts may be analyzed by GC/MSD 

instead of GC/ECD for the purpose of quantitation. 

Data Collection Methods

For this petition, field trials acquiring samples of grass forage and hay were analyzed for residues of 

bifenthrin using FMC method P-2132M. In using this method, residues are extracted with hexane 

using an accelerated solvent extraction system and concentrated. The resulting sample extracts are 

cleaned up using a Florisil column and subsequently quantitated by GC/ECD analysis. For grass 

forage, the calculated LOD of the method is 0.01 ppm and the LOQ is 0.03 ppm. The method 

similarly reports an LOD of 0.03 ppm along with an LOQ of 0.08 ppm for grass hay. The method 

was adequately validated in conjunction with analysis of samples from the field trials.
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

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In regard to the residue chemistry data provided to establish a tolerance on imported tea, many of the 

submissions provided by the petitioner to support this action were found to be incomplete. However, 

the data provided in MRID No. 47920803 for determining the magnitude of residue in tea cultivated 

in India was adequate. For this study, data were acquired using a Gas-Liquid 

Chromatograph/Electron Capture Detection (GLC/ECD) instrumental technique. Although no 

reference number was given for the protocol, it was successfully validated prior to the analysis of 

field samples. 

This method works by macerating a 15-g aliquot of tea sample at moderate speed with acetone,

followed by evaporation and re-constituting it back to a final volume of 250 mL with acetone. An 

aliquot of the extract was then purified by “silica gel” adsorption column clean up using an 18 mm x 

450 mm column packed with anhydrous sodium sulphate and silica gel in tandem using 100 mL of 

hexane. The column in then washed using a 100 mL solvent mixture of hexane:diethyl ether (97:3 

v/v) followed by 50 mL of hexane with all of the washings being discarded. The sample residue is 

then dissolved in 10 mL of hexane and loaded onto a “silica gel” column using another 10 mL of 

hexane and then washed with a 100 mL solvent mixture of hexane:diethyl ether (97.5:2.5 v/v). 

Afterwards, the resulting eluate is then concentrated to near dryness in a rotary evaporator. The 

residue that is acquired is then dissolved in a suitable volume of hexane and quantitated using 

GLC/ECD analysis. An LOD of 0.05 ppm for bifenthrin in tea was reported for the method but no 

LOQ was given.

Conclusions. The existing GC/ECD enforcement methods are adequate for collecting data on 

residues of bifenthrin in both crop and livestock commodities. This includes the revised tree nut test 

procedure submitted by the registrant. These methods will be adequate for enforcing tolerances

established as a result of this petition request. The data collection methods used were likewise shown 

to be adequate for determining the magnitude of bifenthrin in grass forage and hay, as well as in 

imported tea acquired to support this action. 

860.1360 Multiresidue Methods

Bifenthrin TRED; DP No. 283808, S. Levy, 08/21/2002

The Food and Drug Administration’s PESTDATA database dated 10/99 (Pesticide Analytical Manual

(PAM) Vol. I, Appendix II) indicates that bifenthrin is completely recovered using MRM Section 303 

(Mills, Onley, and Gaither Method; Protocol E, non-fatty food) and that recoveries using Section 302 

(Luke Method; Protocol D) are variable. No information pertaining to the recovery of bifenthrin 

using Section 304 (Mills Method; Protocol E, fatty food) is available. Additional MRM data for 

bifenthrin are not required. The MRM methods are adequate for enforcement of bifenthrin 

tolerances. 

860.1380 Storage Stability

DER for MRID 46960801: DP No. 335688, W. Wassell, 07/25/2007

DP Nos. D274839 & D280288, S. J. Levy, 08/15/2002

The maximum storage duration from harvest to analysis was 250 days for grass forage and 244 days 

for grass hay. For tea, only one of the submitted field studies (MRID No. 47920803) provided 

sample storage information. The storage durations and conditions of samples from the crop field 

trials submitted to support this petition are presented below in Table 5.
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

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Table 5. Summary of Storage Conditions and Durations of Samples from Crop Field Trial Studies. 

Matrix Storage Temperature (°C) Actual Storage Duration (days) Interval of Verified Storage Stability (days)

Grass (Forage) -29 to -15 250 229 

Grass (Hay) -29 to -15 244 221

Tea (MRID 47920803) <-18 67 No data available for tea

Tea (other studies) Not reported Not reported No data available for tea

Apple, Nectarines & Peaches Not reported Not Reported 1470

Storage stability studies conducted concurrently with grass crop field trial studies indicate bifenthrin 

is not stable in forge and hay grass when stored frozen for durations greater than 244 to 250 days.

Following correction for laboratory recovery (79% for forage and 77% for hay), average storage 

stability recovery was 65% for forage and 44% for hay. Nonetheless, previously submitted data 

indicate that bifenthrin residues are stable when stored frozen for 12 months in corn flour, 36 months 

in lettuce, pecans and potatoes along with durations up to 49 months in apple (DP Nos. D274839 & 

D280288, S. J. Levy, 08/15/2002). 

Conclusions. The storage conditions and durations of samples from the grass field trials are 

supported by adequate storage stability data. The data indicate that residues decline by approximately

35% in forage and 55% in hay, requiring the correction of residues from the grass field trial data. 

For tea, stability data were not provided which reflect the storage conditions that were incurred in the 

crop field trials that were submitted. However, there are stability studies available or existing data for 

other similar crops which can be translated to substantiate the storage durations that were incurred for 

tea samples in this submission. Similarly, the available apple storage stability data are adequate to 

support the Section 18 request. 

860.1400 Water, Fish, and Irrigated Crops

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

bifenthrin has no registered or proposed uses on water or aquatic food and feed crops.

860.1460 Food Handling

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

bifenthrin has no food-handling uses which are being proposed.

860.1480 Meat, Milk, Poultry, and Eggs

Residue Chemistry Memorandums DP Nos. D335693, D335688, D335696 & D335695, W. Wassell (PP#s 6E7125, 

6E7126, 6E7127, 6E7128), 07/25/2007; DP No. D355743, P.Savoia, 12/08/2008; and DP No. 373487, I. NegrónEncarnación, 04/30/2010.

For this petition, the registration of bifenthrin in treating grass grown for seed will be established for

use to crops grown only in ID, OR, and WA. The forage and hay commodities of grass are used as a 

livestock feedstuff commonly fed to cattle. Although this will be a limited use, there also exists an 

emergency exemption on orchard grass, which when considered together, necessitates that the 

secondary transfer of residues to livestock be assessed. Following current guidelines, dietary burden 

was subsequently re-calculated for bifenthrin using the maximum reasonably balanced diet to 

livestock (Table 6). Because both grass forage and hay are roughage, only grass forage was used in 

this re-calculation since the percent dry matter of this feed will result in greater levels for a more 
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

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conservative evaluation. For this re-assessment, the estimated dietary burden was found to be 1.58 

ppm for beef cattle and 3.63 ppm for dairy cattle. These values are found to be consistent when 

compared to the prior determination of livestock dietary burden made for bifenthrin pursuant to PP#s 

6E7125-6E7128 (DP Nos. D335688, D335693, D335695 & D335696, W. Wassell, 07/25/2007).

Based upon this assessment, HED concludes that the established bifenthrin livestock tolerances 

remain appropriate and do not need to be changed.

 

Table 6. Maximum Reasonably Livestock Dietary Burdens (MRDB) for Bifenthrin.

Feedstuff Type1 % Dry 

Matter2 % Diet2 Tolerance orSTMR/HR3(PPM)

Dietary Contribution 

(ppm)

4

Beef Cattle: 15% R, 80% CC, 5% PC

Grass, forage HR5 R 25 15 1.9751.18

Grain, aspirated fractions MR6 CC 85 5 70.0 (11.2)74.12 (0.33)

Corn, field, grain MR CC 88 75 0.05 0.043

Cottonseed, meal MR PC 92 5 0.5 0.028

TOTAL BURDEN -- -- 100 -- 1.58

Dairy Cattle: 45% R, 45% CC, 10% PC

Grass, forage HR5 R 25 45 1.9753.55

Corn, field, grain MR CC 88 45 0.05 0.026

Cotton, undelinted seed MR PC 88 10 0.5 0.057

TOTAL BURDEN -- -- 100 -- 3.63

Poultry: 75% CC, 25% PC

Corn, field, grain MR CC 88 65 0.05 0.0325

Cowpea/ field pea/lupin seed MR CC 88 10 0.15 0.015

Cottonseed, meal MR PC 85 20 0.5 0.1

Soybean, meal MR PC 92 5 0.2 0.01

TOTAL BURDEN -- -- 100 -- 0.16

Swine: 85% CC, 15% PC

Cor, field, grain MR CC 88 85 0.05 0.0425

Cottonseed, meal MR PC 85 15 0.5 0.075

TOTAL BURDEN -- -- 100 -- 0.12

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

2 OPPTS 860.1000 Table 1 Feedstuffs (June 2008). 

3

Supervised Trial Median Residue/Highest Residue (STMR/HR).

4 Contribution = ([tolerance /% DM] x % diet) for beef and dairy cattle; contribution = (tolerance x % diet) for poultry and swine.

5 Highest Residue (HR).

6 Median Residue (MR).

7 The value in parenthesis represents 16% of the tolerance level for Aspirated Grain Fractions (AGFs). AGFs are normally a composite 

of more than one grain (corn (46%), wheat (36%), sorghum (6%), and soybeans (16%)). Bifenthrin is not registered for use on wheat 

and sorghum. Bifenthrin is registered for use on field corn; however, the requirement for data concerning AGFs from corn has been 

waived as grain samples resulting from the registered use pattern exhibited non-detectable residues of bifenthrin (<0.01 ppm).

Apple wet pomace is a recognized livestock feedstuff for dairy cattle. This processed commodity is 

generally produced only within the prominent apple processing states (e.g., MI, NY, OR, PA, VA, 

WA). It is a seasonal feed item that is used within a 100 mile radius of the processing plant. It is not 

fed to finishing feedlot beef because it would cause digestive problems when fed to an animal that is 

on high-level grain diet and is therefore only fed to local dairy cattle on occasion. For this reason, a 

re-calculation of dietary burden is not being made at this time because the apple use is only being 

established for a time limited emergency exemption. However, if a request is made to establish 

permanent apple tolerances, dietary burden should be re-calculated to consider apple wet pomace.
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

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Conclusions. Establishing tolerances for the commodities of grass grown for seed have been 

concluded to not contribute to the secondary transfer of bifenthrin residues to cattle through feeding. 

Re-calculation of dietary burden has shown that the tolerances established for bifenthrin on livestock 

commodities remain appropriate. In regard to the emergency exemptions which are sought, this a 

time limited use which may have an effect on an alternative feed that is only consumed in small

quantities. A re-calculation of dietary burden considering apple wet pomace should be made if a 

permanent apple tolerance is requested.

860.1500 Crop Field Trials

For PP#9E7652, IR-4 is requesting registration for the use of bifenthrin on grass grown for seed and 

the establishment of a tolerance on imported tea. To satisfy data requirements, IR-4 has submitted a 

study for determining the magnitude of bifenthrin residue found in grass forage and hay. In addition, 

nine (9) studies/reports were included from India, China, Japan, and Indonesia to characterize the 

magnitude of bifenthrin residue found in/on imported tea. No raw data were included in these

submissions and all results presented herein are subsequently summarized from the original 

studies/reports on imported tea provided by IR-4. Many of these submissions are inadequate due to 

the lack of information, such as application rate, PHI, storage length and conditions, and analytical 

methodology. Nevertheless, MRID No. 47920803 is considered to be scientifically acceptable 

though it was found to lack concurrent recovery information. For review, a summary of the residue 

data acquired from these field trial studies which were undertaken are presented below in Table 7.

Table 7. Summary of Residue Data from Grass and Tea Data Acquired for Bifenthrin. 

Commodity Analytes Total App. Rate

(lb ai/acre)

PHI 

(days) n

Residue (ppm)1

Min. Max. HAFT2 Median Mean Std. Dev.

Grass, Grown for Seed

Grass Forage

Bifenthrin 0.199-0.207

29-36 10 0.11 2.18 1.97 0.48 0.73 0.72

Grass Hay 29-43 10 0.20 6.66 6.66 0.32 1.62 2.65

Imported Tea3

Tea

(Fresh leaf)

Bifenthrin 0.053 7

9

0.88 8.80 8.04 6.40 5.20 3.22

Tea

(Processed black tea) 9

0.52 7.78 7.60 6.45 4.86 3.29

1

 For the determination of the HAFT, median, mean, and standard deviation, the LOQ (0.03 ppm) for forage the LOQ of (0.08 ppm) 

for hay and were assumed for residues reported as <LOQ.

2

 HAFT = highest-average field trial.

3

 Imported tea results are summarized from MRID No. 47920803. These residue values have been corrected by a factor of 1.33x to 

provide proportionality between the actual rate of application made at 60g ai/ha not being comparable to the reported GAP maximum 

of 80 g ai/ha. 

Grass grown for seed

DER for MRID No. 47920801, S. Tadayon, 03/22/2010.

IR-4 submitted residue data for five grass (seed crop) field trials conducted in NAFTA growing 

regions Zone 11 (n=2; ID and WA) and Zone 12 (n=3; OR). Each trial consisted of one untreated 

control plot and one treated test plot. The treated plots received two broadcast foliar applications of 

Capture® 2EC (emulsifiable concentrate; 2 lb ai/gallon). The application rates were made at 0.099-

0.104 lb ai/A per application for a total rate of 0.199-0.207 lb ai/A per season with a Re-treatment 

Interval (RTI) of 13-14 days. All applications were made using spray equipment in 24-26 gal/A 

spray volumes without the use of an adjuvant.
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Duplicate samples were harvested. Forage samples were harvested 29-36 days after the last 

application and hay samples were harvested 29-43 days after the last application. The samples were 

analyzed for bifenthrin using a working method very similar to the reference method, “Analytical 

Method for the Determination of Bifenthrin in/on Various Crops and Soils.” P-2132M, FMC 

Corporation, 1989. The method is adequate based on acceptable concurrent and method validation 

recovery data.

The storage data in MRID No. 47920801 show significant degradation can occur over time (35% 

decline in forage and 55% decline in hay, following approximately 230 days in frozen storage). 

Therefore, residues were corrected for potential declines during frozen storage. Following two 

applications of the 2 lb ai/gal EC formulation at a total rate of 0.199-0.207 lb ai/A per season, total 

residues of bifenthrin in grass forage were in the range 0.11-2.18 ppm in samples taken at 29-36 days 

PHI. The total residues of bifenthrin in grass hay were in the range 0.20-6.66 ppm in samples taken 

at 29-43 days PHI.

Conclusions. The submitted residue data made for the grass forage and hay commodities are 

adequate in fulfilling these data requirements. The number and location of field trials were sufficient 

in scope having been undertaken in the Pacific Northwest States of Oregon, Washington, and Idaho 

because this use will be limited to this growing area. They were made appropriately in line with the 

additional guidance requirement on this crop, “Grasses Grown for Seed”, an Agency memorandum 

dated 09/30/2000. This memorandum requires the collection of forage and hay data for this 

commodity since it is considered to be a subgroup of grass pasture and rangeland.

Use of the Organization for Economic Cooperation and Development (OECD) calculation procedures

was made to determine appropriate tolerance levels (Attachment 2). Thus, tolerances of 3.0 ppm for 

grass forage and 6.0 ppm for grass hay are recommended when utilizing the uncorrected values from 

the field trial studies. After correction for storage stability decline, tolerance levels of 4.0 ppm for 

grass forage and 15 ppm for grass hay result. Accordingly, HED recommends a tolerance of 4.0 ppm 

in/on grass forage and 15 ppm in/on grass hay for residues of bifenthrin based on the residue data 

from grass grown for seed. These levels are higher than those proposed by the petitioner and require

a revised Section F for this action.

Tea

DER References: MRID Nos. 47920802 - 47920810

To support the establishment of a bifenthrin tolerance on imported tea, nine (9) studies/reports from 

India, China, Japan, and Indonesia were provided for characterizing the magnitude of residue in/on 

this commodity. Many of these submissions were found to lack detailed information concerning 

application rates, PHI, storage length and conditions, and analytical methodology. For these 

submissions, DERs could not be prepared but the key information they is summarized below. 

MRID No. 47920803

IR-4 has submitted a report summarizing the results of two studies for bifenthrin made on tea 

conducted in India. No raw data were included in the submission and all results noted in the report 

are presented herein.
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

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The FMC Corporation Agricultural Products Group sponsored this study to determine the magnitude 

of bifenthrin residue in black tea and its fresh leaf. The United Planters Association of Southern 

India (UPASI) conducted two field trials in Tamil Nadu, India (municipalities of Valparai and 

Nilgris) and one in Assam, India (municipality of Tocklai). This study was held in an area which is 

representative of the major tea-growing regions in southern and northern India, respectively. One 

treated test plot and one untreated control field was established at each trial site. Each treated plot 

received one application of Talstar 2EC, an emulsifiable concentrate formulation containing 2.0 lb 

bifenthrin/gal (240 g ai/liter). Treatment was made using a hand operated knapsack sprayer applied 

at the targeted rate of 0.053 lb bifenthrin/A (60 g ai/ha). All applications were made with a spray

volume of 53.5 gallons per acre (500 L/ha). Following the industry practice in India of a 7-day PHI 

when treating the crop, tea shoots (three leaves and a bud) were collected from the treated plots for 

testing. From the harvested tea shoots, a portion was processed into black tea with the remaining 

sample submitted for testing as fresh leaf. The samples of black tea and fresh leaf were subsequently

analyzed for residues of bifenthrin. 

For this study, the fresh leaf and black tea samples were analyzed using a GLC/ECD method. 

Quantitation of the tea samples was carried out following extraction with acetone by maceration and 

cleanup with adsorption column chromatography. This method was successfully validated 

beforehand demonstrated through the analysis of fortified samples. The mean recovery of bifenthrin 

ranged from 86.58 to 99.27% using control samples of black tea and fresh leaf fortified at 

concentrations of 0.0593 to 10.0664 ppm for testing. The reported LOD of the method for bifenthrin 

in tea was determined to be 0.05 ppm.

The data submission did note that the maximum storage interval from sampling to completion of 

analysis was 67 days (2.2 months). However, the specific times from sample collection to extraction 

as well as the interval between preparation and final analysis were not reported. No concurrent 

storage stability data were submitted in part with this study. To ensure the integrity of the samples 

were maintained, it was reported that they were kept frozen (<-18 oC) after shipment to the analytical 

laboratory until analysis. In all, the bifenthrin residues obtained from the three field trial locations 

comprising this study ranged from 0.39 to 5.85 ppm in black tea and between 0.66 to 6.62 ppm in the 

fresh leaf samples. It is important to note that the actual application of product made at 60 g ai/ha to 

the tea crop cultivated in this study was approximately 25% less than the reported maximum GAP 

rate of 80 g ai/ha. In order to assume proportionality between the actual rate of application and the 

GAP maximum, a correction factor of 1.33x was applied to this data (Table 7 summary of tea results) 

for interpreting the magnitude of bifenthrin residue in/on tea. Although there were a number of minor 

data deficiencies in both the in-life and analytical phases of the study, it was for the most part 

compliant with the OPPTS 860.1500 Residue Chemistry Test Guidelines. This study aptly shows the 

variation in residue levels which can occur when cultivating tea at different regions following 

common industry practices.

The following studies provided to support this action were considered but not used for tolerance 

setting purposes due to the various deficiencies identified in this assessment.

MRID No. 47920802

IR-4 has submitted a report summarizing the results of two studies for bifenthrin made on tea 

conducted in India. No raw data were included in the submission and all results noted in the report 

are presented herein.
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

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The United Planters Association of Southern India (UPASI) Tea Research Foundation conducted two 

trials at separate locations in Tamil Nadu, India (municipalities of Valparai and Gudalur) 

investigating the magnitude of bifenthrin residue in black tea. Each trial site included two treated 

fields and the use of control plots was not discussed. The first treated plot received one foliar 

broadcast spray application of Talstar 8 SC, a soluble concentrate formulation containing 0.668 lb 

bifenthrin per gallon (80 g ai/L) at a target application rate of 0.018 lb ai/A (0.02 kg ai/ha). The 

second treated plot received one foliar broadcast spray application of Talstar 8 SC at a target 

application rate of 0.036 lb ai/A (0.04 kg ai/ha). All applications were made with a spray volume of 

42.8 gallons per acre (400 L/ha). Following the industry practice in India of a 7-day PHI when 

treating the crop, the green tea leaf samples were collected in line with this protocol. The collection 

of additional samples also occurred on 0, 10, and 14 days after application. This was done to enable a 

residue decline study to be made since other harvesting intervals can occur depending on the season 

and growth rate of the tea crop. The harvested green tea leaves were dried and fermented into black 

tea following standard manufacturing processes for final analysis to determine the extent of bifenthrin 

residue in this end-product.

In a separate study, the Tea Research Association (TRA) conducted a single trial in Assam, India 

(municipality of Tocklai) to likewise investigate the magnitude of bifenthrin residue in black tea. The 

treated plot received a single foliar broadcast spray application of Brigade 8 SC, a soluble concentrate 

formulation containing 0.668 lb bifenthrin per gallon (80 g ai/L) at a target application rate of 0.071 

lb ai/A (0.08 kg ai/ha). The application was made with a spray volume of 42.8 gallons per acre (400 

L/ha) and the use of control plots was not discussed. The green tea leaf samples were harvested at a 

PHI of 7 days following industry protocol with additional samples also being collected on 0, 3, 5, and 

14 days after application. The green tea leaves were then dried and fermented into black tea for final 

analysis to determine the extent of bifenthrin residue in this end-product.

The dried tea samples from the Tamil Nadu trials were analyzed for residues of bifenthrin using a

validated GLC/ECD method. The method LOD of bifenthrin in/on tea was determined to be 0.01 

ppm and no LOQ was reported. The dried tea samples from the Assam trial were analyzed for 

residues of bifenthrin using a validated Gas-Liquid Chromatography/Nitrogen Phosphorous 

Detection/Electron-Capture Detection (GLC/NPD/ECD) procedure. The determined LOD for this 

method is reported to be 0.02 ppm. These analytical procedures are considered to be adequate for 

data collection based on the acceptable method recovery results that were provided.

Sample storage conditions and durations were not delineated in the submission but the stability of the 

analytical standards was checked at periodic intervals throughout the study. For the Tamil Nadu trial,

the submission notes that for any field sample held more than 24 hours, residue stability is 

demonstrated by the recovery studies made to monitor the analytical standards. As for the Assam 

trial, the submission states that all samples were extracted immediately upon receipt in the laboratory

and did not involve extensive storage prior to analysis. Although specific storage durations from 

harvest to extraction could not be determined, storage stability data are not required if the samples 

were stored for less than 30 days.

Residues of bifenthrin ranged from 0.64 to 4.76 ppm in tea harvested 7 days following a single 

broadcast foliar application of Talstar 8 SC for a total foliar rate of 0.018 lb ai/A (0.02 kg ai/ha). 

Residue levels of 2.92 to 7.62 ppm were found in tea harvested 7 days following a single broadcast 

foliar application of Talstar 8 SC for a total foliar rate of 0.036 lb ai/A (0.04 kg ai/ha). Bifenthrin 

concentrations were likewise observed at 0.83 ppm in tea harvested 7 days following a single 

broadcast foliar application of Brigade 8 SC for a total foliar rate of 0.071 lb ai/A (0.08 kg ai/ha).
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

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Results from the residue decline study performed at the Tamil Nadu field sites with application rates

at 0.018 lb ai/A (0.02 kg ai/ha) and 0.036 lb ai/A (0.04 kg ai/ha) were carried out. For this 

determination four sampling intervals corresponding to PHIs of 0, 7, 10, and 14 days indicated that 

residues of bifenthrin declined when the timeframe to collection increased. These results showed that 

residue levels declined rapidly for the first 7 days after application and then continued to diminish at a 

slower rate to Day 14. For this determination, all residues were found to remain above the LOD (0.01 

ppm) out to Day 14. 

Results from the residue decline study performed at the Assam field site with an application rate of 

0.071 lb ai/A (0.08 kg ai/ha) were likewise acquired. For this determination, five sampling intervals

corresponding to PHIs of 0, 3, 5, 7, and 14 days indicated that residues of bifenthrin declined when 

the timeframe to collection increased. Residues were observed to decline quickly for the first 3 days 

after treatment and then continued to lessen at a slower rate to Day 14. Similarly, residue levels were 

all observed to remain above the LOD of 0.02 ppm out to Day 14. The decline rate for the tea crops 

treated at the two lower application levels was more rapid than those which received treatments at the

higher rate.

In addition to the field trial data, this submission also included residue data from the Tetley Group, 

Shanshan Tea, and Finlay Tea. Data received from The Tetley Group lists the results from bifenthrin 

residue analyses of tea in commercial shipments from various countries. The highest residue 

indicated is 0.25 ppm. A summary of bifenthrin residue results from tea grown and analyzed in 

China, obtained from Shanshan Tea, indicates that the highest residues were in the range 1-5 ppm. A 

list of the results of bifenthrin residue analyses of tea originating in India and Japan, from Finlay Tea, 

shows that the highest residue was 0.16 ppm. 

Under the conditions and parameters used in this study, the magnitude of bifenthrin residue was 

demonstrated in the samples of green tea that were acquired. However, in following the OPPTS 

860.1500 Residue Chemistry Test Guidelines, a number of deviations were evident in this data 

submission. Most notably, that only one sample was collected for each field trial and no sample 

storage conditions along with the durations that were incurred are reported. In addition, there are also 

a number of minor data deficiencies pertaining to both the in-life and analytical phases of the studies

which can be attributed to a lack of detailed information.

MRID No. 47920804

IR-4 submitted residue decline data for seven tea trials conducted in India during 1984 and 1985. 

Tea was treated with one application of FMC54800 (10EC) at a dilution rate of 2000X, 3000X, 

4000X, or 6000X. Corresponding application rates were not provided, though the recommended dose 

was reported as 4000X to 6000X. Treated tea samples were collected 30 minutes after application 

and at approximately 1, 3, 7, 10, 14, 17, and 20 days after application. Samples were extracted using 

toluene and xylene, concentrated, cleaned up using a Florisil column, and dried using anhydrous 

sodium sulfate. Quantitation was made using a GC/ECD protocol with average recoveries ranging 

from 87.5 to 98.7% for control samples fortified at 0.1, 1, and 5 ppm. The LOQ of the method was 

reported to be 0.001 ppm with no information on storage duration and conditions being provided. 

Residues in both fresh tea and dry tea trials declined with increasing pre-harvest intervals with a halflife reported for the study to be 3.2 days. At a PHI of 7 days, residues of bifenthrin ranged from 1.52 

ppm to 4.31 ppm. Specifically, residues of bifenthrin in fresh tea were 3.71 ppm and 1.52 ppm at the 
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

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2000X dilution rate and 2.96 ppm and 3.17 ppm at the 4000X dilution rate. In dried tea, the residues 

were 4.31 and 1.22 ppm at the 2000X dilution rate, 1.76 ppm at the 3000X dilution rate, 2.39 ppm 

and 3.09 ppm at the 4000X dilution rate, and 2.07 ppm at the 6000X dilution rate. For this study,

concentrations were such that no residues reached the LOQ by day 20.

In this study residues of bifenthrin in tea soup were also analyzed. Tea was treated with bifenthrin 

and processed on the same day. The tea was soaked in boiling water three times. Average residues 

of bifenthrin were 7.9 ppm in the tea and 0.345 ppm in the tea soup (extraction rate of 4.4%). No 

other information was provided, such as application rate and storage information. In following the 

OPPTS 860.1500 Residue Chemistry Test Guidelines, a number of deviations were evident in this 

data submission. As such, a DER was not completed for this submission because it lacked sufficient 

information concerning the cultivation of the tea samples used to carry out this study. 

MRID No. 47920805

A paper published in Pesticide Science, Volume 23, 1988, pages 109-118, describes the degradation 

of pesticides applied to tea. The paper does not include bifenthrin, but other pyrethroid insecticides 

are discussed in this journal article. Consequently, a DER was not prepared for this data submission 

because it lacked sufficient information. 

MRID No. 47920806

IR-4 submitted residue decline data for tea trials conducted in two locations in China (Xinchang and 

Yuhang, Zhejiang Province) in 2002. The product used in the field trials was 2.5% Talstar EC. Four 

trials were conducted at each location, which consisted of one, two, or three applications at 450 ml/ha 

(0.01 kg ai/ha or 0.009 lb ai/A), or one application made at 1200 ml/ha (0.03 kg ai/ha or 0.02 lb ai/A). 

Tea samples were harvested 7 days after the final application. In Xinchang, samples consisted of 

young buds with one leaf, which were stir-fried to Da-fo Longjing tea and stored until analysis. In 

Yuhang, young buds were collected and stir-fried. 

Two samples were collected from each treated test plot for analysis. Samples from the Xinchang test 

area treated one time at the low rate had a maximum residue of 0.32 ppm. Those which were treated 

twice at the low rate had a maximum residue of 0.42 ppm. The other samples treated three times at 

the low rate had a mean residue of 0.73 ppm along with those being treated once at the high rate had a 

maximum residue of 0.52 ppm. For the Yuhang test area, samples treated one time at the low rate 

had a maximum residue of 1.70 ppm. Alternately, samples treated twice at the low rate had a 

maximum residue of 0.82 ppm. For the samples treated three times at the low rate, a maximum 

residue of 1.96 ppm was found. In regard to the samples treated once at the high rate, maximum 

residues were observed at a concentration of 2.10 ppm. 

For this submission, no information was provided on the analytical method used or storage duration 

and conditions that were incurred. As a result, a DER was not prepared for this study because it 

lacked many of the data requirements of the OPPTS 860.1500 Residue Chemistry Test Guidelines.
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

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MRID No. 47920807

IR-4 has submitted results of a field trial that was conducted in Indonesia in which Talstar 25 

grams/liter EC was applied to fresh, green, and black tea at rates of 0.060 kg a.i./ha (0.054 lb ai/A) 

and 1.0 kg a.i./ha (0.089 lb ai/A). Two samples from each treated test plot were collected, as well as 

two samples from untreated control plots. No further experimental design information was specified, 

including the PHI or storage conditions and intervals. A detailed analytical method for the analysis of 

the samples was provided. The samples were analyzed using either a GC/ECD or GC/MS protocol 

which is referenced as FCC/BIFENTRIN – DRY CROPS/96/1. Briefly, samples were extracted 

using acetone, partitioned using hexane, and purified using a florisil column. Acceptable concurrent 

recoveries were obtained. Maximum residues of bifenthrin in fresh tea leaves were 0.83 ppm (low 

rate) and 3.93 ppm (high rate). Maximum residues in green tea were 3.58 ppm (low rate) and 4.59 

ppm (high rate). Maximum residues in black tea were 1.50 ppm (low rate) and 2.23 ppm (high rate). 

For this submission, a DER was not prepared because it for this study because it lacked many of the 

data requirements of the OPPTS 860.1500 Residue Chemistry Test Guidelines. 

MRID No. 47920808

IR-4 has submitted a report summarizing the results of two studies for bifenthrin made on tea 

conducted in India. No raw data were included in the submission and all results noted in the report 

are presented herein.

For this study, the Institute of Himalayan Bioresource Technology (IHBT) Council of Scientific and 

Industrial Research carried out two (2) field trials in Banuri, Palampur India. It was undertaken to 

investigate the dissipation behavior of bifenthrin residue in tea shoots, processed tea, infused tea 

(brew) and spent tea leaves. One field trial was initiated in the dry season (April, 2003) and another 

in the wet season (July, 2003). Each trial site was comprised of one control parcel and two treated 

test plots that were divided into four subplots to enable the collection of four replicate samples to be 

made at various intervals. The first treated plot received one foliar broadcast spray application of the 

Talstar 8 SC soluble concentrate product containing 0.668 lb bifenthrin per gallon (80 g ai/L) made at 

the rate of 0.036 lb ai/A (40 g ai/ha). The second treated plot received one foliar broadcast spray

application of Talstar 8 SC made at the rate of 0.071 lb ai/A (80 g ai/ha).

All applications were made with a hand operated knapsack sprayer using a spray volume of 42.8 

gallons per acre (400 L/ha). Following the industry practice in India of a 7-day PHI when treating the 

crop, tea shoots (three leaves and a bud) were collected from the treated plots for testing. Green tea 

leaf samples were also harvested from the treated plots at 0 (1 hour after the application), 3, 5, 9, 11, 

14, and 21 days following application to evaluate residue decline. The harvested tea leaves went 

through a manufacturing process which involved withering (reduction of moisture in the shoots), 

rolling, oxidation (fermentation), and drying. The processed tea was further subjected to infusion 

wherein 5 g of the processed tea was infused in 150 mL of boiling water. 

All of the tea sample matrices comprising this study were analyzed for residues of bifenthrin using a 

GC/ECD methodology. The study report notes that the LOD for bifenthrin in all four tea matrices 

(tea shoots, processed tea, infused tea, and spent tea leaves) is estimated to be 0.05 ppm by combining 

the values that were obtained. The study report did not note an LOQ nor were sample storage 

conditions and durations that were incurred provided in the summary. 
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

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Residues levels of bifenthrin in the green tea shoot samples harvested at a PHI of 7-days were found 

to average 0.32 ± 0.03 ppm (dry season) and 0.13 ± 0.02 ppm (wet season) for the Talstar 8 SC 

application made at 0.036 lb ai/A (40 g ai/ha). Residue levels were found to average 0.50 ± 0.05 ppm 

(dry season) and 0.23 ± 0.05 ppm (wet season) following application of Talstar 8 SC made at 0.071 lb 

ai/A (80 g ai/ha). Average residues in the processed tea harvested at the PHI of 7-days were found to 

be 0.38 ± 0.05 ppm (dry season) and 0.18 ± 0.02 ppm (wet season) for the 0.036 lb ai/A (40 g ai/ha)

treatment rate. Alternately, residues averaged 0.60 ± 0.06 ppm (dry season) and 0.21 ± 0.02 ppm 

(wet season) for the application rate made at 0.071 lb ai/A (80 g ai/ha). Residues of bifenthrin were 

not detected in brewed tea from samples harvested at the 7-day PHI for both application rates. For 

the spent tea leaf samples harvested at a PHI of 7-days, residue levels averaged 0.07 ppm (dry season) 

and 0.07 ppm (wet season) following treatment made at the 0.036 lb ai/A (40 g ai/ha) rate. At the 

0.071 lb ai/A (80 g ai/ha) application rate, residues were found to average 0.11 ppm (dry season) and 

0.05 ppm (wet season) in the spent tea leaves harvested at the PHI of 7-days.

Residue decline studies were made for each application rate using sampling intervals which 

corresponded to PHIs of 0, 1, 3, 5, 7, 9, 11, 14, and 21 days. These results indicate that residues of 

bifenthrin in tea decline with increasing pre-harvest intervals for collection. The residues declined 

rapidly for the first 3 days after the application and then continued the decline at a slower rate until 

they were undetectable. By Day-11, bifenthrin was undetectable in all matrices for both the dry and 

wet season trials. Overall, residues of bifenthrin degraded more rapidly in wet season tea than in dry

season tea. The study also notes that the processing of green tea shoots contributes to a considerable 

loss of bifenthrin (≥ 42%) and only a partial transfer of residues (1.5% to 14%) when brewed. 

Under the conditions and parameters used in this study, the magnitude of bifenthrin residue was 

shown in the tea samples that were acquired. However, in following the OPPTS 860.1500 Residue 

Chemistry Test Guidelines, a number of deviations were evident in this data submission which 

adversely affects the completeness of this study. Most notably, the timing of the product applications 

is not known, it is uncertain if adjuvants were used, meteorological conditions for the field trials were

not reported, and the sample storage conditions as well as durations are not provided. In addition, it 

is not known if the analytical method was previously validated, no individual data points were 

reported (only mean values with some standard deviations), and no raw data were provided to support 

the reproducibility of the method or the lack of potential interferences.

MRID No. 47920809

IR-4 submitted residue decline data for four tea trials conducted in Japan during 1985 and 1987. 

Limited experimental design data was provided for three of the trials that were made. For these three 

trials, tea was treated with two applications of Talstar 2 WP at a 1,000X dilution (2 g ai/hl), with a 

final spray volume of 4,000 l/ha. Based on these parameters, the resulting single application rate was 

0.08 kg ai/ha (0.07 lb ai/A), for a total application rate of 0.16 kg ai/ha (0.14 lb ai/A). Tea was 

treated at a weekly interval. Tea was harvested at intervals of approximately 7, 14, 21, and/or 28 

days. The tea tree was covered by shade for 7 to 13 days before harvest. The number of samples 

collected per treated test plot was not provided. Additionally, sample storage conditions and duration 

were not provided. 

Briefly, the method works by extracting the samples using acetone. After removal of acetone, NaCl 

solution was added and the sample is extracted again with dichloromethane. The water and organic 

solvent was removed from the dichloromethane layer and the fraction is concentrated. The sample 

fraction is purified with florisil column chromatography and partitioned with a mixture of acetonitrile 
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

Page 20 of 34

and hexane. The residues are then quantitated using GC/ECD analysis with concurrent recovery data 

(two samples at one fortification level) provided to show the proficiency of the procedure. The LOQ 

for the method was reported to be 0.005 ppm to 0.01 ppm respectively for each tea matrix analyzed.

Processed tea leaves from the four trials had mean residues in the ranges 5.12-36.0 ppm after a PHI of 

one-week, 0.976-17.8 ppm at two weeks, and 0.442-4.97 ppm after three weeks. At a PHI of 6 days, 

the maximum individual residue from all four trials was 36.2 ppm in processed tea. However, in 

brewed tea, the respective residue ranges were 0.014-0.04 ppm, <0.005-0.04 ppm, and <0.005-0.01 

ppm. The maximum individual bifenthrin residue was 0.074 ppm. For this submission, a DER was 

not prepared because it for this study because it lacked many of the data requirements of the OPPTS 

860.1500 Residue Chemistry Test Guidelines. 

MRID No. 479208010 

IR-4 has submitted a report summarizing the results of two studies which total 16 field trials made for 

bifenthrin on tea that were conducted in China during the 2006 and 2007 growing seasons. No raw 

data were included in the submission and all results noted in the report are presented herein.

The FMC Plant Protection Company held sixteen (16) trials at two locations in the Guangdong and 

Zhejiang Provinces of China. It was carried out to investigate the magnitude of bifenthrin and 

imidacloprid residues found in fresh green tea leaves, processed tea, and soil occurring in these 

regions. As such, only the findings pertaining to the use of bifenthrin for cultivating fresh tea leaves 

and the occurrence of any residues retained in its processed end-product are addressed in this 

summation. 

For the field trials conducted in 2006, five (5) established plots in Yingde City of the Guangdong 

Province and Zhuji City of the Zhejiang Province were utilized in this portion of the study. The first 

plot in each province received one foliar spray application of 15% imidacloprid-bifenthrin SC soluble 

concentrate formulation made at the target application rate of 60 ml/mu. The second plot in each 

province received two foliar spray applications of this test product made at 60 ml/mu treatments for a 

total application rate of 120 ml/mu. The third plot in each province received one treatment of the test 

product made at 90 ml/mu with the forth parcel in each province receiving two sprays at the 90 

ml/mu rate for a total application of 180 ml/mu. The fifth plot did not receive any treatments of the 

test product and was used for the collecting control samples. The report did not provide enough 

information about the test product to allow for a calculation of the application rate specific to 

bifenthrin to be made as the active ingredient. The petition submitted by the registrant only notes that 

the application rates of bifenthrin used in this study were 22.5 g ai/ha and 33.75 grams ai/ha made 

using a spray volume of 600 liters/ha. No supporting data were likewise provided in the petition to 

enable the targeted application rates for study to be verified as well. 

The study was again repeated during the 2007 growing season held at the same locations using the 

same number of test plots. For this phase of the study, the same test product was again applied using 

the same targeted treatment rates to provide an additional eight field trials for evaluation. It was 

noted that all applications were made with a spray volume of 64.1 gallons per acre (600 L/ha). In 

regard to the test plots which were designated to receive two spray treatments, the intervals for 

application were reported to range from 5 to 7 days. Triplicate tea leaf samples were harvested at 3, 7 

and 10 day PHIs. The harvested tea leaves were collected from the field and subsequently

manufactured into the processed end-product. 
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

Page 21 of 34

All of the tea sample matrices comprising this study were analyzed for residues of bifenthrin using a 

GC/ECD methodology. The reported LOD for bifenthrin in/on fresh tea leaves and the processed tea

end-product was determined to be 0.01 ppm for both sample matrices. The study report did not note 

an LOQ but acceptable method recovery results were provided demonstrating the test procedure was 

adequate for data collection. The submission did note that all fresh tea leaf and processed tea samples 

were stored at -20oC. However, the sample storage durations that were incurred for this study are not 

noted and no discussion of the stability of bifenthrin in tea held under similar conditions is given in 

the submission. 

For the fresh green tea leaf samples, mean residues of bifenthrin were found to decrease from 0.038 

(Day-3) to 0.012 ppm (Day-10) following a single application of 15% SC test product made at the 60 

ml/mu rate. Following two treatments made at the total application rate of 120 ml/mu, mean residues

of bifenthrin were observed to decrease from 0.066 (Day-3) to 0.015 ppm (Day-10) in the fresh green 

tea leaf samples. Alternately, after a single application of 15% SC test product made at the 90 ml/mu

rate, mean residues of bifenthrin were found to decrease from 0.068 (Day-3) to 0.018 ppm (Day-10) 

in the fresh green tea leaves. For the treatments made at the total application rate of 180 ml/mu, mean 

residues of bifenthrin were similarly observed to decrease from 0.092 (Day-3) to 0.024 ppm (Day-10)

in the fresh green tea leaves.

In regard to the processed tea samples, mean residues of bifenthrin were found to decrease from 

0.086 (Day-3) to 0.023 ppm (Day-10) following a single application of 15% SC test product made at 

the 60 ml/mu rate. Following two treatments made at the total application rate of 120 ml/mu, mean 

residues of bifenthrin were observed to decrease from 0.068 (Day-3) to 0.013 ppm (Day-10) in the 

processed tea samples. After a single application of 15% SC test product made at the 90 ml/mu rate, 

mean residues of bifenthrin were found to decrease from 0.117 (Day-3) to 0.026 ppm (Day-10) in the 

processed tea samples. For the treatments made at the total application rate of 180 ml/mu, mean 

residues of bifenthrin were similarly observed to decrease from 0.111 (Day-3) to 0.031 ppm (Day-10)

in the processed tea samples.

Mean residues of bifenthrin did not exceed 0.13 ppm in either the fresh green tea leaves or processed 

tea samples for any number of applications or treatment rates tested in this study. Under the 

conditions and parameters used in this study, the magnitude of bifenthrin residue was shown in the 

tea samples that were acquired. However, in following the OPPTS 860.1500 Residue Chemistry Test 

Guidelines, a number of deviations were evident in this data submission which adversely affects the 

completeness of this study. Most notably, there was not enough information provided to calculate the 

rate of application, the timing of the treatments made are not known, application intervals were not 

reported, meteorological conditions for the field trials were not reported, and whether adjuvants were 

used are not noted. In addition, there was no discussion supporting the stability of bifenthrin in 

samples stored at -20oC, and no raw data were provided to support the reproducibility of the method 

or the lack of potential interferences.

Conclusions. For the purpose of establishing a tolerance on imported tea, many of the submissions 

provided are inadequate because they fail to provide application rates, PHIs, storage length and 

conditions, and raw data to support the analyses that were made. Nevertheless, MRID No. 47920803 

is considered to be scientifically acceptable for demonstrating the magnitude of bifenthrin residue 

found in tea. In a prior action made for Ethiprole, three tea field trials were considered sufficient for 

registration since tea contributes to <0.05% of the diet for any one population subgroup relevant to 

the United States (DP No. D382875, S. Piper, 11/29/2010). Similarly, the three (3) tea field trials 
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

Page 22 of 34

contained in MRID No. 47920803 support the establishment of a bifenthrin tolerance on imported 

tea. 

In general, all tea which is consumed domestically is imported with the major exporters of tea to the 

United States from 2004-2008 being Argentina, (20.2%), Canada (24.6%), Mexico (13.5%), China 

(11.5%), and India (5.2%). However, Canada and Mexico are not major tea producers, but rather 

they simply import product for re-packaging and export into the United States. Based on the relative 

amounts imported from countries that are actually major producers, the three (3) trials provided in 

MRID No. 47920803 are representative in showing the magnitude of bifenthrin residue in/on 

imported tea.

Apples, Nectarines, and Peaches (Section 18 Emergency Exemption)

Residue Chemistry Memo DP No. D274839 and D280288, 08/15/2002, S. Levy (includes a review of MRID Nos. 

45377302 and 45377303 submitted for determining the magnitude of the residue in Pears).

For depicting the magnitude of bifenthrin residues in/on apples, nectarines, and peaches, field trial 

studies made on pears are available which support prior actions undertaken for this active ingredient. 

The most recent data submission for pears was acquired in a 1998 to evaluate the use of different 

spray volumes (MRID Nos. 45377302 and 45377303). In establishing this emergency exemption, the 

same use pattern supported by the representative pear crop data was proposed for treating apples, 

nectarines, and peaches. A summary of the residue data are presented below in Table 8.

Table 8. Summary of Residue Data from the Pear Crop Field Trials with Bifenthrin.

Commodity Total Applic. 

Rate

(lb ai/A)

PHI 

(days)

Residue Levels

(ppm)

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

Pears 0.5 14 3 0.10 0.38 0.32 0.18 0.21 0.10

1

 Except for sample min/max, values reflect per trial averages; n = no. of field trials. For calculation of median, mean, and standard 

deviation, the LOQ (0.05 ppm) was used for any results reported as <LOQ or between the LOQ and LOD in the table.

2

 HAFT = highest-average-field-trial.

Previously submitted crop field trial data for pears have been determined to be adequate to support 

the proposed tolerance for residues of bifenthrin per se in/on pears at 0.5 ppm (PP#6F3454; CB Nos. 

6715 and 7036-7044, 10-JAN-1991, N. Dodd). The results from the most current crop field trial 

studies made in pears have shown that residues of bifenthrin to range between 0.10-0.38 ppm. These 

were the residue levels found in/on pears harvested 14 days following the last of three foliar 

applications of the 10% WP formulation of bifenthrin at 0.1, 0.2, and 0.2 lb ai/A in a spray volume of 

~400 GPA for a total rate of 0.5 lb ai/A (1x the maximum proposed seasonal rate for pears). The 

submitted pear field trial data are classified as acceptable and satisfy the guideline requirement for 

crop field trials (Residue Chemistry Guidelines OPPTS 860.1500) in conjunction with previously

submitted pear field trial data. However, the field trial data were concluded to be insufficient in

supporting the petitioner’s request to add lower spray volumes to the proposed label for pears. For 

this data collection effort, the petitioner was instructed to submit a revised Section F for "pear" at 

0.50 ppm.

Conclusions. For the purpose of establishing a time limited emergency exemption on apples, 

nectarines, and peaches, studies are available which examine the use of the 10% WP (EPA Reg. No. 

279-3108) and 2 lb/gal EC (EPA Reg. No. 279-3069) formulations in treating pears. In support of the 

use made on pears, applications were administered at the seasonal rate of 0.5 lbs.ai/A (0.45 lbs ai/A 
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

Page 23 of 34

post-bloom) following a 14 day PHI. The submitted pear data were found to be adequate in 

satisfying the OPPTS 860.1500 test guideline requirements used in a establishing a permanent 

tolerance limit of 0.5 ppm on this commodity (DP Nos. D274839 & D280288, S. J. Levy, 

08/15/2002). This dataset is therefore concluded to be appropriate for translation to apples, 

nectarines, and peaches for this Section 18 action only. 

860.1520 Processed Food and Feed

Grass grown for seed

HED does not require residue data for any processed commodities associated with grass grown for 

seed. Therefore, data requirements for processed food and feed are not relevant to this tolerance 

petition.

Tea

In support of this petition request, a formal processing study for tea was not provided but the testing 

of the black tea processed end-product was made in part with each of the field trials which were 

carried out. Following the industry practice of adhering to a 7-day PHI when treating the crop, tea 

shoots (three leaves and a bud) were collected from the treated plots for testing. From the harvested 

tea shoots, a portion was processed into black tea with the remaining sample submitted for testing as 

fresh leaf. The samples of black tea and fresh leaf were subsequently analyzed for residues of 

bifenthrin.

Each of the field trial sites used for study were comprised of both untreated control and treated test 

plots. The treated plots received application at accepted industry GAP rates using foliar spray

bifenthrin products. Seven days after treatment, a sample of tea shoots (three leaves and a bud) was 

harvested from each plot and divided into two parts. One part was taken as the fresh leaf sample and 

the other was processed into the black tea end-product following the cut-turn-curl production method, 

or CTC, as described in the original studies. In general, black tea is processed by first withering it to 

reduce the moisture in the shoots at ambient temperature for a period of 20-22 hours. It is then rolled 

for 30 minutes mechanically followed by maceration of the leaf with 2 additional passes through the 

CTC machine’s sharp cutting ridges. Finally, it is fermented at 90-95% relative humidity for 60-75 

minutes and then dried for 30 minutes at 90-95 oC to form the black tea end-product.

For these studies, data were acquired using GLC/ECD instrumental techniques. Quantitation of the 

tea samples was carried out following extraction with acetone by maceration and cleanup with 

adsorption column chromatography. Reference numbers were not given for these protocols, but all 

the procedures were successfully validated prior to the analysis of field samples. Mean residue 

values of bifenthrin were found to range from 0.031 to 3.91 ppm in/on the fresh tea leaf samples 

analyzed in the three subject field trial studies which tested tea both commodities in this manner. 

Following processing into the dried black tea end-product, the resulting mean residue values which 

were obtained in these studies were observed ranging from 0.041 to 3.66 ppm. Further evaluation of 

the data acquired for processed black tea indicates that bifenthrin residues do not concentrate

significantly in this dried end-product: an average processing factor of 1.12x was determined as 

shown in Table 9.
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

Page 24 of 34

Table 9. Residue Data for the Black Tea Processed End-Product with Bifenthrin.

Field Trial Study Tea Commodity PHI 

(days)

Mean Residues (ppm) Processing Factor1

MRID No. 47920803 Fresh Leaf 7 3.91 0.94

Processed Black Tea 3.66

MRID No. 47920808 Fresh Leaf 0.36 1.11

Processed Black Tea 0.40

MRID No. 47920808 Fresh Leaf 0.031 1.32

Processed Black Tea 0.041

AVERAGE 1.12

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

in the fresh leaf. 

Apples, Nectarines, and Peaches (Section 18 Emergency Exemption)

The Agency requires a processing study for wet apple pomace. However, For the purposes of this 

Section 18 only, no apple processing study is required. 

860.1650 Submittal of Analytical Reference Standards

Analytical standards for bifenthrin furnished by FMC Agricultural Products are currently available in 

the EPA National Pesticide Standards Repository (personal communication with Theresa Cole, 

BEAD, 04/26/2012). However, this stock of standards is noted to begin expiring in 2013. Analytical 

reference standards of bifenthrin must be supplied and supplies 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 and 860.1900 Confined/Field Accumulation in Rotational Crops

Bifenthrin TRED; DP# 283808, 8/21/02, S. Levy

An adequate confined rotational crop study was reviewed by the Environmental Fate and Effects 

Division (EFED) in conjunction with an earlier bifenthrin petition (Memo, E. Regelman, 

08/07/1987). From this data it was concluded that a 30-day Plant-Back Interval (PBI) would be 

appropriate for leafy vegetables and root crops with additional data being needed for an assessment of 

grain crops to be made. A field rotational crop study made with wheat was subsequently provided by

the registrant to fulfill data requirements for grain crops. In this study, residues of bifenthrin were 

found to be <0.01 ppm in/on grain, forage, hay and straw from wheat planted 30 days following the 

last of five treatments made to a primary crop at 0.1 lb ai/A/application. Based on the available 

confined and field rotational crop data, HED concluded that all existing rotational crop restrictions 

are appropriate for bifenthrin (DP No. D283808, S. J. Levy, 08/21/2002). Crops with established 
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

Page 25 of 34

bifenthrin tolerances may be rotated at any time with all others holding to a 30-day PBI following a 

final application of bifenthrin. No rotational crop tolerances are required. 

860.1550 Proposed Tolerances

Tolerances for residues of bifenthrin are currently expressed in terms of the parent compound only. 

Permanent tolerances are established for bifenthrin residues in/on several food commodities under 40 

CFR §180.442(a)(1). The established tolerances for plant and livestock commodities, under 

§180.442(a)(1), range from 0.05 ppm (various plant and poultry commodities) to 70 ppm (grain, 

aspirated fractions). A tolerance of 0.05 ppm is also established for residues of bifenthrin in 

food/feed handling establishments under §180.442(a)(2). In addition, time-limited tolerances for 

residues of bifenthrin have been established under §180.442(b) in connection with Section 18 

emergency exemptions; these include tolerances for orchardgrass, forage and hay at 2.5 ppm and 4.5 

ppm, respectively, with a 12/31/12 expiration date. 

IR-4 has submitted a study for determining the magnitude of bifenthrin residue found in grass forage 

and hay. These data were entered into the OECD calculation procedures to determine appropriate 

tolerance levels (Appendix 1). Using the OECD calculation procedures, a tolerance of 3.0 ppm for 

residues in/on grass forage and 6.0 ppm in/on grass hay are recommended when utilizing the 

uncorrected values from the field trial studies. After correction for storage stability decline, tolerance 

levels are 4.0 ppm in/on grass forage and 15 ppm in/on grass hay. HED recommends a tolerance of 

4.0 ppm in/on grass forage and 15 ppm in/on grass hay for residues of bifenthrin based on the residue 

data obtained from the field trials that were provided. 

For this petition, the registration of bifenthrin for treating grass grown for seed will limit this use only

to ID, OR and WA. The forage and hay commodities of grass are often used as a livestock feedstuff 

typically fed to cattle. For this reason, dietary burden was subsequently re-calculated for bifenthrin 

following current guidelines using the maximum reasonably balanced diet to livestock. Because both 

grass forage and hay are roughage, only grass forage was used in this re-calculation since the percent 

dry matter of this feed will yield greater levels for a more conservative evaluation. For this recalculation, the values which were found are consistent when compared to the prior determination of 

livestock dietary burden made for bifenthrin pursuant to PP#s 6E7125-6E7128 (DP Nos. D335688, 

D335693, D335695 & D335696, W. Wassell, 07/25/2007). HED concludes that the established 

bifenthrin livestock tolerances would remain appropriate and do not need to be increased.

For the purpose of establishing an appropriate tolerance on imported tea, nine (9) studies/reports 

completed abroad were provided to show the magnitude of bifenthrin residue in/on this commodity. 

However, many of the submissions provided were inadequate because they fail to provide application 

rates, PHIs, storage lengths and conditions, and raw data to support the analyses that were made. 

Nevertheless, MRID No. 47920803 is considered to be scientifically acceptable for demonstrating the 

magnitude of bifenthrin residue found in tea. Although the registrant requests the tolerance for tea be 

established on plucked leaves, the fresh tea leaf is not imported into the United States which 

necessitates that any level be set only on dried tea. 

Based on an examination of all the study data provided to support this petition, residues of bifenthrin 

were found not to concentrate in the processed dried tea end-product. Using the OECD calculation 

procedures, a rounded MRL of 20 ppm was determined for dried tea (Attachment 2). These residue 

values were first corrected for the deficit that was apparent in the rate of application (1.33x) because 
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

Page 26 of 34

the subject study was approximately 25% less than the reported maximum GAP rate. However, to 

harmonize with Codex, HED recommends a tolerance level of 30 ppm for dried tea. 

For determining the magnitude of the residue in/on apples, nectarines, and peaches, the OECD 

calculation procedures were not used because pear data supporting prior actions made for this 

representative commodity were considered. The most recent data submission for pears was acquired 

in a 1998 to evaluate the use of different spray volumes (MRID Nos. 45377302 and 45377303). The 

application pattern for this use on pears prescribes a seasonal rate of 0.5 lbs.ai/A (0.45 lbs ai/A postbloom) made as multiple treatments at a 30-day RTI following a 14 day PHI. From this dataset 

acquired with this use pattern, it was concluded that a 0.5 ppm tolerance would be appropriate for the 

use of 10% WP bifenthrin product in treating this representative crop (DP. Nos. D274839 & 

D280288, S. Levy, 08/15/2002). In establishing this emergency exemption, the same use pattern 

supported by the representative pear crop data will be put forward for treating apples, nectarines, and 

peaches to mitigate stink bug infestation in these affected states. 

Table 10. Tolerance Summary for Bifenthrin

Crop Group or Commodity Proposed Tolerance 

(ppm)

Recommended 

Tolerance (ppm)

Comments; Correct Commodity 

Definition

Apple -- 0.5 Specified in (b) Section 18 

emergency exemption; Apple

Grass, forage 2.5 4.0 Specified in (c) Tolerances with 

regional registrations; 

Grass, hay 4.5 15 Specified in (c) Tolerances with 

regional registrations; 

Nectarine -- 0.5 Specified in (b) Section 18 

emergency exemption; Nectarine

Peach -- 0.5 Specified in (b) Section 18 

emergency exemption; Peach

Tea 25 30 Specified in (a) General; Tea, dried

References

DP Nos.: 274839 and 280288

Subject: PP#6F03454. Bifenthrin On Pear and Nut, Tree, Group. Evaluation of Residue Data 

and Analytical Methods. 

From: S. J. Levy and G. Kramer

To: G. LaRocca

Dated: 08/12/2002

MRID Nos: 45377301-45377305

DP No.: 283808

Subject: Bifenthrin. Residue and Product Chemistry Considerations for the Tolerance 

Reassessment Eligibility Decision (TRED) 

From: S. J. Levy

To: T. Myers

Dated: 08/21/2002

MRID Nos: None
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

Page 27 of 34

DP No.: 384283

Subject: Review of Tolerance Enforcement Method for Bifenthrin. DP Barcode #384283. 

ACB Project # B11-10. 

From: C. J. Stafford

To: J. Arthur

Dated: 12/22/2010

MRID No.: 45377301

DP No.: 286230

Subject: Bifenthrin (PC Code: 128825). Petitioner’s Responses to HED Residue Chemistry

Deficiencies Identified in the Tolerance Reassessment Eligibility Decision (TRED) 

Document (Memo, S. Levy, 21-AUG-2002; D283808). 

From: S. J. Levy

To: T. Myers

Dated: 10/17/2002

MRID Nos.: None

DP Nos.: 335693, 335688, 335696, 335695

Subject: Bifenthrin (Chemical No. 128825). PP#6E7125, PP#6E7126, PP#6E7127, 

PP#6E7128; Section 3 Registration for Application of Bifenthrin to Mayhaw, Root 

Vegetables, (Except Sugar Beets, Crop Subgroup 1B), Peanut, Pistachio, Soybean, and 

Fruiting Vegetables (Crop Group 8). Summary of Residue Chemistry Data. 

From: W. Wassell

To: D. Rosenblatt and S. Brothers

Dated: 07/25/2007

MRID Nos: 46098701, 46960801, 46961101-46961103, 46960401-46960404

DP No.: 355743

Subject: Bifenthrin. Bridging Study Supporting Use of an Emulsifiable Concentrate 

Formulation on Tree Nuts. Summary of Analytical Chemistry and Residue Data.

From: P. Savoia

To: G. LaRocca

Dated: 12/08/2008

MRID No.: 47433601

DP No.: 382875

Subject: Ethiprole. Request for Tolerance without U.S. Registration in/on Imported Rice and 

Tea. Summary of Analytical Chemistry and Residue Data.

From: S. Piper

To: C. Rodia

Dated: 11/29/2010

MRID Nos.: 47622720-47622727

Attachments: 

1. International Residue Limit Status sheet

2. Tolerance Assessment Calculations
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

Page 28 of 34

Attachment 1. International Residue Limits

Bifenthrin (128825; 04/03/2012)

Summary of US and International Tolerances and Maximum Residue Limits 

Residue Definition:

US Canada Mexico2 Codex3

40 CFR 180.442:

Plants/Livestock: Bifenthrin (2-methyl 

[1,1′-biphenyl]-3-yl) methyl-3-(2-

chloro-3,3,3,-trifluoro-1-propenyl)-2,2-

dimethylcyclopropanecarboxylate

None bifenthrin (sum of 

isomers). The residue is 

fat-soluble.

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

US Canada Mexico2 Codex3

Apple 0.5

Grass, forage 4.0

Grass, hay 15

Nectarine 0.5

Peach 0.5

Tea, dried 10 30 (proposed) Tea, 

Green, Black (black, 

fermented and dried)

Completed: M. Negussie; 04/03/2012

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.

Tea, green and black

Supervised trials on green and black tea (dry) were available from China, India, Indonesia and Japan.

In China, the registered use for bifenthrin in tea is foliar spray treatment at 0.0075–

0.053 kg ai/ha and a PHI of 7 days. The Meeting received ten Chinese trials treated with 2 × 0.045–

0.048 kg ai/ha and a PHI of 7 days which were considered still consistent with Chinese GAP. The
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

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residues were in dried tea in ranked order (n = 10): 0.04, 0.07, 0.08, 0.08, 0.08, 0.09, 0.09, 0.11, 1.2

and 4.3 mg/kg.

Three trials from India treated with 0.06 kg ai/ha and a PHI of 7 days were submitted. The

application rate was in the limit of ± 25% of Chinese GAP. The residues were in dried tea 0.42, 5.1

and 5.9 mg/kg.

The GAP in Japan is 2 × 0.08 kg ai/ha and a PHI of 14 days. Three Japanese trials according

to GAP were submitted. The residues were in dried tea 1.3, 5.2 and 18 mg/kg.

One Indian (1 × 0.08 kg ai/ha, PHI 14 days) and one Indonesian trial (0.06 and 0.10 kg ai/ha,

PHI 10 days) were considered still consistent with Japanese GAP. The residues were in dried tea 0.47

and 4.6 mg/kg.

The Meeting agreed to use the Japanese trials supported by the results of the Indian and

Indonesian trials to estimate a maximum residue level.

The Meeting estimated a maximum residue level and an STMR for bifenthrin in tea, green

and black, of 30 mg/kg and 5.2 mg/kg, respectively.

Statistical calculations for only three data points were not adequate.
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Attachment 2. Tolerance Assessment Calculations.

Grass (grown for seed)

The dataset used to establish a tolerance for bifenthrin on grass grown for seed forage and hay

consisted of field trial data acquired for these commodities. The data reflect application rates of 

0.199-0.207 lb ai/A/season (2 applications at 0.099-0.104 lb ai/A/application) of an EC formulation 

with a 29- to 36-day PHI for forage and 29- to 43-day PHI for hay. This field trial data appropriately

quantified the expected range of residues in these commodities following treatment according to the 

Good Agricultural Practice (GAP) proposed for this pattern of use. In this study, the application rates 

were all made at the maximum rate following minimum re-treatment and harvest intervals. It is 

important to note that the PHIs for three (3) of the five (5) trials did exceed this criterion for hay. All 

field trial sample results obtained for grass forage and hay were found to be above the LOQ (LOQ = 

0.03 ppm for forage; LOQ = 0.08 ppm for hay).

To establish appropriate tolerance levels on grass forage and hay, these data were entered into the 

Organization for Economic Cooperation and Development (OECD) calculation procedures for 

determination. For those field trials where sampling replicates were taken, the average or mean value 

was used for calculation. The mean residue values corrected for storage stability decline used to 

calculate the tolerance levels are provided in Table I-1 for forage and Table I-2 for hay. These field 

trial results acquired for bifenthrin on grass forage and hay do in fact represent a small dataset of only

3-7 residue values. In using the OECD calculation procedures with small datasets, there can be a

considerable level of uncertainty in the resulting MRL value for this statistical determination. 

Nonetheless, for datasets of this size where uncertainty can be high, the results obtained are justifiable 

given the non-distributional approach followed by the OECD calculation procedures and the great 

variability which exists in the data.

When using the OECD calculation procedures, the resulting MRL value is always found to be greater 

than or equal to the highest residue within the dataset. MRLs are displayed without decimal zeros 

after the last significant figure and are rounded in the last step of calculation to produce a result in the 

region of the 95th percentile. For grass forage, storage stability loss was found to occur at 35% so the 

corrected data was appropriately used for calculation. The MRL estimate calculated at the “Mean + 4 

SD” recommends a tolerance level for bifenthrin on grass forage at 4 ppm. In regard to grass hay, the 

data entered for calculation were likewise adjusted because storage stability loss was found to occur 

at 55% for this commodity. The MRL estimate calculated at the “Mean + 4 SD” recommends a 

tolerance level for bifenthrin on grass hay at 15 ppm. 
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Inputs for calculating statistically based pesticide tolerances.

Table I-1 Inputs for Grass Forage

BiFenthrin

Grass Forage(Corrected)

US (Restricted to ID, OR & WA)

PHI = 29-36 Days

Total number of data (n) 5

Percentage of censored data 0%

Number of non-censored data 5

Lowest residue 0.130

Highest residue 1.960

Median residue 0.480

Mean 0.724

Standard deviation (SD) 0.747

Correction factor for censoring (CF) 1.000

Proposed MRL estimate

- Highest residue 1.960

- Mean + 4 SD 3.711

- CF x 3 Mean 2.172

Unrounded MRL 3.711

Rounded MRL 4

High uncertainty of MRL estimate.

[Small dataset]

Residues (mg/kg)

0.13

0.2

0.48

0.85

1.96
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Table I-2 Inputs for Grass Hay

Bifenthrin

Grass Hay (Corrected)

US (Restricted to ID, OR & WA)

PHI = 29-36 Days

Total number of data (n) 5

Percentage of censored data 0%

Number of non-censored data 5

Lowest residue 0.220

Highest residue 6.650

Median residue 0.320

Mean 1.624

Standard deviation (SD) 2.815

Correction factor for censoring (CF) 1.000

Proposed MRL estimate

- Highest residue 6.650

- Mean + 4 SD 12.885

- CF x 3 Mean 4.872

Unrounded MRL 12.885

Rounded MRL 15

High uncertainty of MRL estimate.

[Small dataset]

Residues (mg/kg)

0.22

0.26

0.32

0.67

6.65
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Tea, dried

The dataset used to establish a tolerance for bifenthrin on tea (dried) consisted of field trial data 

acquired for this commodity. The data reflect one application of Talstar 2EC, an emulsifiable

concentrate formulation containing 2.0 lb bifenthrin/gal (240 g ai/liter). Treatment was made as a 

foliar spray applied at the targeted rate of 0.053 lb bifenthrin/A (60 g ai/ha). All applications were 

made with a spray volume of 53.5 gallons per acre (500 L/ha). Following the industry practice in 

India of a 7-day PHI when treating the crop, tea shoots (three leaves and a bud) were collected from 

the treated plots for testing. From the harvested tea shoots, a portion was processed into black tea

with the remaining sample submitted for testing as fresh leaf. The samples of black tea and fresh leaf 

were subsequently analyzed for residues of bifenthrin.

To establish appropriate tolerance levels on tea, the data for the processed dried tea end-product were 

entered into the Organization for Economic Cooperation and Development (OECD) calculation 

procedures for determination. These residue values were first corrected for the deficit that was 

apparent in the rate of application (1.33x) because the subject study was approximately 25% less than 

the reported maximum GAP rate. For those field trials where sampling replicates were taken, the 

average or mean corrected value was used for calculation. These field trial results entered on dried 

tea do in fact represent a small dataset of only 3-7 residue values. In using the OECD calculation 

procedures with small datasets, there can be a considerable level of uncertainty in the resulting MRL 

value for this statistical determination. Nonetheless, for datasets of this size where uncertainty can 

be high, the results obtained are justifiable given the non-distributional approach followed by the 

OECD calculation procedures and the great variability which exists in the data.

When using the OECD calculation procedures, the resulting MRL value is always found to be greater 

than or equal to the highest residue within the dataset. MRLs are displayed without decimal zeros 

after the last significant figure and are rounded in the last step of calculation to produce a result in the 

region of the 95th percentile. The MRL estimate for bifenthrin on dried tea was 20 ppm (see Table I3). For harmonization with Codex, HED recommends a tolerance level of 30 ppm for dried tea. 
Bifenthrin Summary of Analytical Chemistry and Residue Data DP No. 388604

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Table I-3 Inputs for Tea, dried

Bifenthrin

Tea, dried

Import (India)

7-day PHI

Total number of data (n) 3

Percentage of censored data 0%

Number of non-censored data 3

Lowest residue 0.530

Highest residue 7.590

Median residue 6.450

Mean 4.857

Standard deviation (SD) 3.790

Correction factor for censoring (CF) 1.000

Proposed MRL estimate

- Highest residue 7.590

- Mean + 4 SD 20.017

- CF x 3 Mean 14.570

Unrounded MRL 20.017

Rounded MRL 20

High uncertainty of MRL estimate.

[Small dataset]

Residues (mg/kg) n

0.53 1

6.45 1

7.59 1