Thiacloprid Summary of Analytical Chemistry and Residue Data DP#: D406397 

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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460

OFFICE OF CHEMICAL SAFETY AND 

 POLLUTION PREVENTION

MEMORANDUM

 Date: 31 October 2012 

Subject: Thiacloprid: Request for Food Uses on Stone Fruits and Peppers. Amended 

Summary of Analytical Chemistry and Residue Data. 

PC Code: 014019 DP Barcode: D406397 

Petition Nos.: PP#0F7706, PP#0E7704 Registration No.: 264-806, 264-807 

Assessment Type: Single Chemical Regulatory Action: Section 3 Registration 

TXR No.: N/A Registration Case No.: N/A 

Decision No.: 430158 CAS No.: 111988-49-9 

MRID No.: 47947701, 45829901, 45829902, 

45829903, 46677901, 46677902 

40 CFR 180.594 

From: Michael A. Doherty, Ph.D., Senior Chemist 

 Risk Assessment Branch II 

 Health Effects Division (7509P) 

Through: Elizabeth Holman, Chemist 

 Risk Assessment Branch II 

 Health Effects Division (7509P) 

To: Andrew Ertman/Barbara Madden (Team 05) 

 Risk Integration, Minor Use, and Emergency Response Branch 

 Registration Division (7505P) 

 Marianne Lewis/Venus Eagle (Team 01) 

 Insecticide-Rodenticide Branch 

 Registration Division (7505P) 

This document updates the previous residue chemistry summary to (1) include the review of the 

soybean and wheat rotational crop studies and (2) provide the results of Organisation for 

Economic Cooperation and Development (OECD) harmonized MRL calculation procedures. 

Executive Summary

Thiacloprid, 3-[(6-chloro-3-pyridinyl)methyl]-2-thiazolidinylidene cyanamide, is a neonicotinoid 

insecticide that Bayer CropScience and Interregional Research Project Number 4 (IR-4) have 

proposed for use on pepper (bell and non-bell) and the stone fruit crop group. Thiacloprid would 

be applied foliarly to peppers and stone fruits as an aerial or airblast spray made from a 40% 
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active ingredient (a.i.) flowable formulation (Calypso 4 Flowable). Applications would be made 

to stone fruits at a maximum single application rate of 0.25 lb ai/A, with a minimum 7-day 

retreatment interval (RTI). The total application rate would not exceed 0.38 lb ai/A/season and 

the preharvest interval (PHI) would be 14 days. For peppers, the proposed label specifies a 

maximum single application rate of 0.094 lb ai/A, a 7-day RTI, and a 7-day PHI. The total 

application rate for peppers would not exceed 0.28 lb ai/A/season. 

Concurrently, Bayer CropScience and IR-4 have submitted petitions (PP#s 0F7706 and 0E7704, 

respectively) to establish tolerances for thiacloprid and its thiazolidine containing metabolites in 

or on the following commodities: pepper (bell and non-bell) at 1.1 ppm and fruit, stone, group 

12, at 0.5 ppm. This Summary Document addresses the adequacy of the residue chemistry data 

submitted to support those petitions. 

The nature of the residue has been adequately defined for purposes of this petition. The residue 

definition for tolerance enforcement is thiacloprid only. For risk assessment, the residue 

definition is thiacloprid plus metabolites with an intact thiazolidine ring. A previously approved 

analytical method, using HPLC-MS/MS, is available for tolerance enforcement. 

Residue data from bell peppers, non-bell peppers, cherries, peaches, plums (fresh and dried) are 

supported by adequate storage stability studies. The residue trial data are acceptable and show 

residues ranging from <0.01 to 0.18 ppm in/on bell peppers, <0.01 to 0.22 ppm in/on non-bell 

peppers, <0.02 to 0.26 ppm in/on sweet cherry, 0.03 to 0.42 in/on peaches, and <0.02 to 0.03 

ppm in/on plums. Residues increased by 2.6X fold during drying of plums into prunes. The 

NAFTA Harmonized Tolerance/MRL Calculator suggests tolerances of 0.60 ppm for peppers 

and 0.70 ppm for stone fruit, except plum. The calculated tolerance level for plum is 0.05 ppm. 

The recommended tolerances (see below) for residues in peppers and stone fruit (except plum) 

have been revised from the calculated values in order to harmonize with Codex. 

Residue Chemistry Deficiencies

Prior to Registration – Section F. A revised Section F should be submitted to address the 

following issues with the proposed tolerances and tolerance definition: 

Pepper (bell and non-bell): The submitted residue data for bell peppers and non-bell 

peppers are adequate to support a Codex-harmonized tolerance of 1.0 ppm pending 

submission of a revised Section F in order to: (i) propose a lower tolerance level, from 

1.1 ppm; and (ii) reflect the preferred Agency food and feed commodity vocabulary: 

from “pepper (bell and non-bell)” to “pepper”. 

Stone Fruits (Crop Group 12): The submitted residue data for cherries, peaches, and 

plums, the representative commodities of stone fruits, are adequate to support a Codexharmonized crop group tolerance of 0.50 ppm (except plum) pending submission of a 

revised Section F in order to (i) reflect the preferred Agency food and feed commodity 

vocabulary: from “stone fruit” to “fruit, stone, group 12”, and (ii) to provide for a 

separate tolerance of 0.05 ppm for residues in/on plum. 

The tolerance definition should be revised to be in terms of the parent compound only 
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(i.e., Compliance with the tolerance levels is to be determined by measuring only 

thiacloprid, (Z)-[3-[(6-chloro-3-pyridinyl)methyl]-2-thiazolidinylidene]cyanamide. 

Prior to Registration – Label Issues. Section B of the petition indicates that registration is being 

requested for both Calypso® 4 Flowable and Calypso® 70 WG. It is HED’s understanding that 

the 70 WG product is not actually part of the petition. A revised Section B should be submitted 

in which only the Calypso® 4 Flowable product is listed. 

Based on the results of the field rotational crop studies with soybean and wheat, soybean and 

cereal grains may be added to the list of crops that may be rotated after a 30-day plant-back 

interval. 

Conditional Data – Field Accumulation in Rotational Crop Data. Limited field accumulation 

studies in wheat and soybeans were required per previous HED review (11 June 2003, D279818, 

D. Soderberg) and have been submitted to the Agency (MRIDs 46677901 and 46677902). A 

review of these studies is included herein. 

Note: The current tolerance expression is not consistent with the recommendation made by HED 

in its 2003 assessments or with current guidance regarding tolerance language. The current 

tolerance definition is: 

“Tolerances for combined residues of the insecticide thiacloprid ([3-[(6-chloro-3-

pyridinyl)methyl]-2-thiazolidinylidene] cyanamide) and metabolites retaining the 

thiazolidine ring intact, measured and expressed in terms of thiacloprid, per se, in or on 

the following commodities:” 

HED recommends that the CFR be revised to specify the following tolerance expression: 

“Tolerances are established for residues of thiacloprid, including its metabolites and 

degradates, in or on the commodities in the table below. Compliance with the tolerance 

levels specified below is to be determined by measuring only thiacloprid ([3-[(6-chloro3-pyridinyl)methyl]-2-thiazolidinylidene] cyanamide).” 

Residue Chemistry Conclusions

For the requested uses on bell and non-bell peppers (PP#0E7704) and stone fruit (PP# 0F7706), 

there are no major residue chemistry issues that would preclude granting permanent tolerances 

and Section 3 registrations for the requested uses. Prior to granting any registrations, the issues 

detailed above should be considered. The proposed uses and the submitted data support the 

following tolerances for residues of thiacloprid in/on: 

Pepper ..............................................................................................1.0 ppm 

Fruit, stone, group 12, except plum .................................................0.50 ppm 

Plum .................................................................................................0.05 ppm 

Except for plums, the recommended tolerance levels are harmonized with existing Codex MRLs. 

The significantly different residue levels in the trials with plums as compared to the other 
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representative commodities in the stone fruit crop group make it necessary to set a separate 

regulatory level for residues in plums. 

A human health risk assessment is forthcoming. 

Background

Thiacloprid {3-[((6-chloro-3-pyridinyl)methyl]-2-thiazolidinylidene cyanamide} is a 

neonicotinoid insecticide that is effective for the control of various insects including aphids, 

leafhoppers, plant bugs, whiteflies, leafminers, mired bugs, codling moths, plum curculio, scales 

and maggots. The active ingredient is formulated as 40% a.i. flowable formulation (Calypso 4 

Flowable) or a 70% a.i. in a wettable granule formulation (Calypso 70 WG). Foliar applications 

are applied aerially or by ground sprayer. 

The first food/feed uses of thiacloprid were approved on cotton and pome fruits (Crop Group 

11). The residue chemistry data supporting these crop uses are summarized by HED in a June 

11, 2003 memo (DP#s 279818, D. Soderberg). Tolerances are currently established [40 CFR 

§180.594] for the combined residues of the insecticide thiacloprid ([3-[(6-chloro-3-

pyridinyl)methyl]-2-thiazolidinylidene] cyanamide) and metabolites retaining the thiazolidine 

ring intact, measured and expressed in terms of thiacloprid, per se, in/on pome fruit, group 11 at 

0.30 ppm; wet apple pomace at 0.60 ppm, cotton, undelinted seed at 0.02 ppm; cotton gin 

byproducts at 11.0 ppm; and animal commodities at 0.02-0.15 ppm. 

The chemical structure and nomenclature of thiacloprid are presented in Table 1. The 

physiochemical properties of the technical grade of thiacloprid are presented in Table 2. 

TABLE 1 Test Compound Nomenclature. 

Compound 

Chemical Structure: 

Common name Thiacloprid 

Company experimental name YRC 2894, 

IUPAC name [3-[(6-Chloro-3-pyridinyl)methyl]-2-thiazolidinylidene]cyanamide 

CAS name (Z)-[3-[(6-chloro-3-pyridinyl)methyl]-2-thiazolidinylidene]cyanamide 

CAS # 111988-49-9 

End-use product/EP Calypso® 4 Flowable Insecticide; EPA Reg. No. 264-806 
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TABLE 1 Test Compound Nomenclature. 

Compound 

(primary metabolite) 

Chemical Structure: 

Common name Thiacloprid amide metabolite 

Company experimental name YRC 2894 amide 

IUPAC name (Z)-[3-[(6-Chloro-3-pyridinyl)methyl]-2-thiazolidinyldene)urea 

CAS name unknown 

CAS # 676228-91-4 

End-use product/EP Not applicable 

Compound 

(primary metabolite) 

Chemical Structure: 

Common name Thiacloprid hyrdoxy amide metabolite 

Company experimental name 4-hydroxy YRC 2894 amide , 

IUPAC name Urea, N-[(2Z)-3-[(6-chloro-3-pyridinyl)methyl]-4-hydroxy-2-thiazolidinylidene] 

CAS name unknown 

CAS # unknown 

End-use product/EP Not applicable 

Table 2 Physicochemical Properties of the Technical Grade Test Compound

Parameter Value 

Melting point/range 136° C 

pH 7.40 at 20° C 

Density 1.46 g/mL at 20° C 

Water solubility ( 20 ̊C) 185 mg/L 

Solvent solubility (g/L) n-Heptane: < 0.1 

Xylene: 0.30 

1-Octanol:1.4 

2-Propanol: 3.0 

Ethyl acetate: 9.4 

Polyethylene glycol (PEG): 42 

Acetonitrile: 52 

Acetone: 64 

Dimethylsulfoxide (DMSO): 150 

Dichloromethane: 160. 

Vapor pressure at 20 & 25° C 23 x 10 (-10) Pa at 20° C 

8 x 10(-10) Pa at 25° C 

Dissociation constant (pKa) AI has no basic or acidic properties in aqueous solutions 
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Table 2 Physicochemical Properties of the Technical Grade Test Compound

Parameter Value 

Octanol/water partition coefficient 

Log(KOW) 

KOW

1.26 at 20° C 

18 

UV/visible absorption spectrum λ max Extinction coefficient

295-300 nm 49.1828 

301-305 nm 39.3463 

 860.1200 Directions for Use 

The petitioners (Bayer CropScience and IR-4) submitted draft labels dated 2/26/10 for the 4 lb 

ai/gal SC formulation (Calypso® 4 Flowable; EPA Reg. No. 264-806). Both labels were 

identical, except the label submitted by Bayer CropScience also included use on peppers. In 

Section B of both petitions, the petitioners state that two formulated products consist of a 

flowable concentrate at 40.4% a.i. and a wettable granular (WG) at 70% a.i. A specimen label 

was not provided for the 70% WG formulation. It is HED’s understanding that the 70% WG 

formulation is not actually part of the petition. A summary of the proposed use patterns for the 

40.4% a.i. product is detailed in Table 3. 

Table 3. Summary of Directions for Use of Thiacloprid. 

Applic. Timing, 

Type, and Equip. 

Formulation Applic. 

Rate 

(lb ai/A) 

Max. No. 

Applic. per 

Season 

Max. 

Seasonal 

Applic. Rate 

(lb ai/A) 

PHI 

(days) 

Use Directions and 

Limitations 

Stone Fruit Group 12 

Foliar application Calypso 4 

Flowable 0.25 

Not 

Specified 0.38 14 

Near lakes, rivers, 

permanent streams, 

marshes or natural 

ponds, estuaries, and 

commercial fish farm 

ponds: no aerial 

application within 100 

feet; do not allow 

airblast spray to go 

beyond cultivated area. 

Pepper 

Foliar application Calypso 4 

Flowable 0.094 

Not 

Specified 0.281 7 

Near lakes, rivers, 

permanent streams, 

marshes or natural 

ponds, estuaries, and 

commercial fish farm 

ponds: no aerial 

application within 100 

feet; do not allow 

airblast spray to go 

beyond cultivated area. 
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The following rotational crop restrictions are specified for the 4 lb/gal SC formulation: Roots, 

tubers and bulb vegetables whose tops are not used for feed may be rotated with cotton after a 

plan back interval of 30 days. Leafy vegetables may be rotated after a 6 month plant back 

interval. Do not plant any other crop in the treated area for at least one year after application. 

Conclusions. The submitted labels for the 4 lb ai/gal SC formulation (Calypso® 4 Flowable; 

EPA Reg. No. 264-806) appropriately reflect the conditions used in the thiacloprid field trials 

and are adequate to allow evaluations of the residue data relative to the proposed uses. Although 

the flowable formulation was not tested in either the pepper or stone fruit trials, 480 SC 

(suspension concentrate) formulation was tested. Since a flowable formulation can be 

considered equivalent to a suspension concentrate formulation from a residue chemistry 

perspective, the field trials are adequate to cover use of the 40.4% a.i. flowable formulation as 

well as the 70 WG% formulation. 

Based on the results of the field rotational crop studies with soybean and wheat, soybean and 

cereal grains may be added to the list of crops that may be rotated after a 30-day plant-back 

interval. 

860.1300 Nature of the Residue – Plants 

Residue Chemistry Memo DP# 279818, 6/11/2003, D. Soderberg (PP#9F06060) 

Residue Chemistry Memo DP# 288833, 4/7/2003, D. Soderberg (HED MARC Decision Document)

The nature of the residue has been adequately defined for cotton, rice, tomatoes, apples and the 

rotational crops: wheat, turnips and lettuce. By far the most predominant residue is thiacloprid, 

per se, in plants. In general, where metabolism occurs, the thiazolidine ring is less stable than 

the pyridinyl ring and the bridge methylene group generally tends to cleave on the thiazolidine 

side. Plants do not appear to metabolize thiacloprid at all; but metabolism does occur in soil, and 

plants can translocate such metabolized residues of thiacloprid from the soil and sometimes 

subsequently form further conjugates of them. In plants and animals, the residue of concern is 

parent only for the purposes of tolerance assessment and parent and metabolites with intact 

thiazolidine ring for risk assessment (DP# 288833, 4/7/2003, D. Soderberg; HED Metabolism 

Assessment Review Committee). 

Conclusion: For the purposes of the current tolerance petitions, the available apple and tomato 

metabolism studies are considered sufficient to delineate the nature of the residues. The residues 

of concern remain thiacloprid, per se. 

860.1300 Nature of the Residue – Livestock 

There are no livestock feedstuffs associated with the request to establish tolerances on peppers 

and stone fruit. Therefore, data requirements for livestock metabolism are not relevant to the 

current tolerance petitions. 

860.1340 Residue Analytical Methods
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Residue Chemistry Memo DP# 279818, 6/11/2003, D. Soderberg (PP#9F06060) 

Enforcement methods

Previously, Bayer had submitted three potential enforcement methods for determining residues 

of thiacloprid in/on plants. They included the following: (1) HPLC/UV method for determining 

thiacloprid, per se, in/on plants; (2) GC/MS method for determining residues of thiacloprid as the 

common moiety 6-CNA in/on plants; and (3) HPLC-MS/MS method for determination of 

thiacloprid, thiacloprid amide and hydroxythiacloprid amide in/on plants. The HPLC-MS/MS 

for plants is adequate for enforcement of thiacloprid in plants. 

Data-collection methods

Samples of stone fruits (sweet cherry, peach, and plum) collected from the magnitude of the 

residue and processing studies were analyzed for residues of thiacloprid, thiacloprid amide 

metabolite, and thiacloprid hydroxyl amide metabolite using the University of California, Davis 

working method derived from Bayer Ag. Draft Method, “Modified Residue Analytical Method 

for the Determination of YRC 2894, YRC 2894-Amide and 4-Hydroxy-YRC 2894-Amide 

Residue in Pecan Matrices” (April 8, 2001) with modifications. The limit of quantitation (LOQ), 

defined as the lowest level of method validation (LLMV) at which acceptable recovery can be 

achieved for this HPLC-MS/MS method, was 0.02 ppm for each analyte in all matrices. The 

method is acceptable based on concurrent recoveries. 

Samples of peppers (bell and non-bell) collected from the magnitude of the residue studies were 

analyzed for residues of thiacloprid and its metabolites, YRC 2894 amide and 4-hydroxy YRC 

2894 amide, using a method titled “An analytical method for the determination of YRC 2894, 

amide-YRC 2894, 4-hydroxy YRC 2894 amide, and YRC 2894 sodium sulfonate residues in 

various plant matrices by HPLC-MS/MS.” The LOQ, defined as the LLMV at which acceptable 

recovery can be achieved, was 0.01 ppm for each analyte. The method is acceptable based on 

concurrent recoveries. 

Conclusions. An adequate HPLC-MS/MS is available for determination of thiacloprid residues 

in plant matrices. This method can be supported by existing radiovalidation and metabolism 

data. This method has adequate confirmatory ions available in the MS as described in the ILV. 

HED recommends that Bayer propose this method for tolerance enforcement in plant tissues. 

Residues of thiacloprid, thiacloprid amide metabolite, and thiacloprid hydroxyl amide metabolite 

in/on peppers (bell and non-bell) and stone fruit (sweet cherry, peach, plum) were determined 

using acceptable data collection methods. 

860.1360 Multiresidue Methods 

Residue Chemistry Memo DP# 279818, 6/11/2003, D. Soderberg (PP#9F06060) 

Multiresidue method testing data were previously submitted for thiacloprid as part of the data 

package for PP#9F06060. This study has been forwarded to the Analytical Chemistry 

Laboratory; Biological and Economic Analysis Division of OPP for review. A brief examination 
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of the submitted study (MRID 44927625) indicates that thiacloprid may be suitable for analysis 

via Protocol D. 

860.1380 Storage Stability

Residue Chemistry Memo DP# 279818, 6/11/2003, D. Soderberg (PP#9F06060) 

The storage durations and conditions of samples from the residue field trials and processing 

studies which were submitted to support the current petitions are presented in Table 4. 

Table 4. Summary of Storage Conditions and Durations of Samples from Crop Field Trial and 

Processing Studies. 

Matrix 

[MRID] 

Storage Temperature 

(°C)

Actual Storage Duration Interval of Demonstrated 

Storage Stability 

Peppers, fresh fruit 

[47947701] 

-22 to -24 60-220 days 

(2.0-7.2 months) 18 months 1 

Sweet cherry, fresh fruit 

[45829903] 

<-20 78-138 days 

(2.6-4.6 months) 139 days 2 

Peach, fresh fruit 

[45829902] 

<-20 13-109 days 

(0.4-3.6 months) 162 days 2 

Plum, fresh fruit 

[45829901] 

<-20 83-176 days 

(2.7-5.8 months) 161 days 2 

Dried Plum 

[45829901] 

<-20 119-133 days 

(3.9-4.4 months) 120 days 2 

1

 Storage stability data translated from DP# 279818, 6/11/2003, D. Soderberg. 

2 Storage stability determined from concurrent field trial samples. 

Conclusions. Adequate storage stability data for apples, tomatoes, and melons were reviewed in 

PP#9F06060. It was shown that thiacloprid per se is stable under frozen conditions in apples, 

tomatoes, and melons for up to 18 months. By translation, these storage stability data support 

the pepper residue field trials for the current petition. 

To support the current stone fruit field trial data, storage stability studies were conducted in 

conjunction with the field trials. For each crop, control samples of the respective matrices were 

fortified with thiacloprid, thiacloprid amide metabolite, and thiacloprid hydroxy amide 

metabolite at target level of 0.200 ppm and placed in storage under the same frozen conditions as 

the treated samples. No zero-day analyses were conducted on the fortified samples placed into 

storage. Rather, triplicate stored samples were analyzed along with a control sample and freshly 

fortified samples at an interval reflecting the maximum storage intervals from the field trials. 

Average corrected recoveries of thiacloprid following frozen storage were 95% from sweet 

cherry after 139 days, 100% from peach after 162 days, 98% from plum after 161 days, and 

104% for dried plum after 120 days. These storage stability data support the stone fruit (sweet 

cherry, peach, and plum) field trial and processing (dried plum) studies. 

There are no unresolved storage stability issues, and no corrections need to be applied to the 

various residue crop studies. 
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860.1400 Water, Fish, and Irrigated Crops

There are no proposed or registered uses that are relevant to this guideline topic. 

860.1460 Food Handling

There are no proposed or registered uses that are relevant to this guideline topic. 

860.1480 Meat, Milk, Poultry, and Eggs

There are no significant livestock feedstuffs associated with the proposed use on peppers and 

stone fruit. Therefore, data requirements pertaining to meat, milk, poultry, and eggs are not 

relevant to the current tolerance petitions. 

860.1500 Crop Field Trials

Pepper (bell and non-bell)

DER Reference List 47947701.der.doc 

Bayer CropScience has submitted field trial data for thiacloprid in/on bell peppers and non-bell 

peppers. Nine field trials were conducted, six on bell peppers and three on non-bell peppers in 

the US. The bell pepper trials were in Zones 2 (GA, 1 trial), 3 (FL, 1 trial), 5 (NE, 1 trial), 6 

(TX, 1 trial), and 10 (CA, 2 trials). The non-bell pepper trials were in Zones 2 (GA, 1 trial), 3 

(FL, 1 trial), and 10 (AZ, 1 trial). One treated plot and one untreated control plot were 

established at each trial site. For each trial, three foliar applications of the test substance YRC 

2894 480 SC (a suspension concentrate formulation nominally containing 4 lb ai/gal thiacloprid) 

were made at a target rate of 0.094 lb ai/A/application, with re-treatment intervals (RTI) of 5 to 8 

days. The total target application rate was 0.282 lb ai/A/season (~1x the proposed maximum 

seasonal rate of 0.281 lb ai/A). All applications were made using ground equipment at spray 

volumes of 10 to 34 gallons per acre (GPA). There were no adjuvants added to the spray 

mixture. Pepper (fresh fruit) samples were collected at pre-harvest intervals (PHIs) of 0, 2-3, and 

6-7 days. At one trial site (Y4066-01D), samples were collected at PHIs of 0, 3, 7, 10 and 14 

days to assess residue decline. 

Residues of thiacloprid and its metabolites, YRC 2894 amide and 4-hydroxy YRC 2894 amide, 

were determined using a method titled “An analytical method for the determination of YRC 

2894, amide-YRC 2894, 4-hydroxy YRC 2894 amide, and YRC 2894 sodium sulfonate residues 

in various plant matrices by LC/MS-MS.” The limit of quantitation (LOQ), defined as the 

lowest level of method validation (LLMV) at which acceptable recovery can be achieved, was 

0.01 ppm for each analyte. The limit of detection (LOD) was determined to be 0.001 ppm for 

thiacloprid and 4-hydroxy YRC 2894 amide and 0.002 for YRC 2894 amide. The method is 

acceptable based on concurrent recoveries. 

 

The maximum storage duration from sampling to extraction was 220 days (7.2 months). All 

sample extracts were analyzed within 6 days of extraction. Available storage stability indicate 

that residues of thiacloprid, per se, are stable in tomatoes for up to 18 months when stored frozen 
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at < -18 C (DP# 279818, 6/11/2003, D. Soderberg). No storage stability data are available for 

residues of thiacloprid amide and thiacloprid hydroxy amide in peppers or fruiting vegetables, 

however, these residues have been shown to be stable during freezer storage (<-20oC) for at least 

161 days in plum (MRID 45829901), 139 days in cherries (MRID 45829903) and 162 days on 

peaches (MRID 458299 02). Based on translation, adequate storage stability data are available 

to support the storage conditions and durations for the pepper study. 

Following three foliar broadcast applications of thiacloprid at a total target application rate of 

0.282 lb ai/A, residues of thiacloprid ranged from 0.040 to 0.209 ppm in/on bell peppers 

harvested at a 0-day PHI, from 0.014 to 0.224 ppm in/on bell peppers harvested at a PHI of 2-3 

days and from <0.01 to 0.180 ppm in/on bell peppers harvested at a PHI of 6-7 days. For nonbell peppers, residues of thiacloprid ranged from 0.052 to 0.344 ppm at a 0-day PHI, from <0.01 

to 0.333 ppm at a PHI of 2-3 days and from <0.01 to 0.221 ppm at a PHI of 6-7 days. Residues 

of YRC 2894 amide and 4-hydroxy YRC 2894 amid were less than the LOQ in all samples. A 

summary of residue data from the pepper trials is presented in Table 5. 

The residue decline study showed that residues of thiacloprid in/on peppers declined between 

Day 0 and Day 14. 

Table 5. Summary of Residue Data from Pepper Field Trials with Thiacloprid.

Commodity Total Applic. 

Rate 

 (lb ai/A) 

PHI 

(days) 

Residue Levels (ppm)

n Min. Max. HAFT Median 

(STMdR) 

Mean 

(STMR) 

Std. Dev. 

Proposed use pattern: Foliar applications made at a single maximum of 0.094 lb ai/A/application, for a total of 0.281 lb 

ai/A/season; 7-day PHI 

Thiacloprid 

Bell Pepper 0.281 - 0.287 6-7 12 <0.01 0.180 0.132 0.030 0.053 0.051 

Non-bell 

Pepper 

0.281 - 0.287 7 6 <0.01 0.221 0.210 0.006 0.073 0.106 

Amide Metabolite 

Bell Pepper 0.281 - 0.287 6-7 12 <0.01 <0.01 <0.01 <0.01 <0.01 NA

Non-bell 

Pepper 

0.281 - 0.287 7 6 <0.01 <0.01 <0.01 <0.01 <0.01 NA

Hydroxy Amide Metabolite 

Bell Pepper 0.281 - 0.287 6-7 12 <0.01 <0.01 <0.01 <0.01 <0.01 NA

Non-bell 

Pepper 

0.281 - 0.287 7 6 <0.01 <0.01 <0.01 <0.01 <0.01 NA

Conclusions. The submitted residue data for pepper (bell and non-bell) are adequate to fulfill 

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

Guideline 860.1500. The trials reflect the proposed use pattern. 

Stone fruit (group 12)

DER Reference List 45829901.der.doc (plum) 

 45829902.der.doc (peach) 

 45829903.der.doc (sweet cherry)

Cherry, Sweet: The IR-4 Project at Rutgers, The State University of New Jersey has submitted 

field trial data for thiacloprid in/on sweet cherries. Seven field trials were conducted in the US 
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during the 2001 season in Zones 5 (MI, 2 trials), 10 (CA, 2 trials), and 11 (WA, 1 trial; ID, 1 

trial; and OR, 1 trial). One treated plot and one untreated control plot were established at each 

trial site. For each trial, two foliar applications of the test substance, Calypso 480SC (a 

suspension concentrate formulation containing 4 lb/gal of the active ingredient, thiacloprid), 

were made at a target rate of 0.125 lb ai/A/application for the first application and 0.250 lb ai/A 

for the second application, with retreatment intervals (RTIs) of 6 - 8 days. The total target 

application rate was 0.375 lb ai/A/season (~1x the proposed maximum seasonal rate of 0.38 lb 

ai/A). All applications were made using ground equipment in 62 to 364 GPA; no adjuvant was 

added to the spray mixtures. Samples of mature sweet cherries were harvested at PHIs of 13-14 

days and 25-28 days. At one trial site (07812.01-WA25), an additional bulk sample of sweet 

cherries were collected from the field site to determine the effect of washing, cooking, and 

drying the sweet cherries on thiacloprid residues. 

Residues of thiacloprid, thiacloprid amide metabolite, and thiacloprid hydroxy amide metabolite 

were determined using University of California, Davis working method derived from Bayer Ag. 

Draft Method “Modified Residue Analytical Method for the Determination of YRC 2894, YRC 

2894-Amide and 4-Hydroxy-YRC 2894-Amide Residue in Pecan Matrices” (April 8, 2001) with 

modifications. The limit of quantitation (LOQ), defined as the lowest level of method validation 

(LLMV) at which acceptable recovery can be achieved, was 0.02 ppm for each analyte. The 

limit of detection (LOD) was determined to be 0.003 ppm for each analyte. The method is 

acceptable based on concurrent recoveries. 

The maximum storage duration from sampling to extraction was 138 days (4.6 months). All 

sample extracts were analyzed on the day of extraction. To evaluate storage stability, a 

concurrent storage stability study was conducted using control samples of cherries fortified with 

thiacloprid, thiacloprid amide metabolite, and thiacloprid hydroxy amide metabolite at target 

level of 0.200 ppm. These samples were stored frozen (<-20 oC) and then analyzed at 139 days 

with freshly fortified samples. The results show that residues of thiacloprid, thiacloprid amide 

metabolite, and thiacloprid hydroxy amide are stable in cherry RAC for up to 139 days when 

stored frozen. These data support the residue data from the cherry field trial samples. 

Residues of thiacloprid ranged from <0.020 ppm to 0.263 ppm on sweet cherries harvested at a 

PHI of 13-14 days following two foliar applications of the Calypso 480SC at a total rate of 

0.371-0.385 lb ai/A. Residues of the thiacloprid amide metabolite and thiacloprid hydroxy 

amide metabolite were all less than the LLMV (0.020 ppm). The residue data are summarized in 

Table 6. 

Peach: The IR-4 Project at Rutgers, The State University of New Jersey has submitted field trial 

data for thiacloprid on peaches. Eleven field trials were conducted in the US in Zones 1 (NY, 1 

trial), 2 (NJ, 1 trial; NC, 2 trials), 3 (FL; 1 trial), 5 (MI; 1 trial), 6 (TX; 1 trial), 10 (CA; 3 trials), 

and 11 (ID; 1 trial). One treated plot and one untreated control plot were established at each trial 

site; at the North Carolina and Florida trials, two treated plots were established. For each trial, 

two foliar applications of the test substance, Calypso 480SC (a suspension concentrate 

formulation containing 4 lb/gal of the active ingredient, thiacloprid), were made at a target rate 

of 0.125 lb ai/A for the first application and 0.250 lb ai/A for the second application for a total 

seasonal rate of 0.375 lb ai/A (~1x the proposed maximum seasonal rate of 0.38 lb ai/A). The 
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retreatment interval (RTI) was 6 - 8 days. At the NJ trial, the second application was under 

applied by approximately 51%, for a total of approximately 0.245 lb ai/A. At the NY trial, a 

third application was made at approximately 0.250 lb ai/A, for a total of approximately 0.625 lb 

ai/A, to allow the peaches to mature; the third application was made at a 13-day RTI. All 

applications were made using ground equipment in 50 to 300 GPA; no adjuvant was added to the 

spray mixtures. Samples of peaches were harvested from the untreated and treated plots at 12 to 

15 days and at 21 to 29 days following the final application. At the North Carolina and Florida 

trials, samples were collected from one treated plot at a PHI of 14 days and from the second 

treated plot at a 28-day PHI. At one trial site (01-NC11), an additional bulk sample of peaches 

was collected from the field site to determine the effect of washing, cooking, and drying on 

thiacloprid residues. 

Residues of thiacloprid, thiacloprid amide metabolite, and thiacloprid hydroxy amide metabolite 

were determined using University of California, Davis working method derived from Bayer Ag. 

Draft Method “Modified Residue Analytical Method for the Determination of YRC 2894, YRC 

2894-Amide and 4-Hydroxy-YRC 2894-Amide Residue in Pecan Matrices” (April 8, 2001), with 

modifications. The limit of quantitation (LOQ), defined as the lowest level of method validation 

(LLMV) at which acceptable recovery can be achieved, was 0.02 ppm for each analyte in all 

matrices. The method is acceptable based on concurrent recoveries. 

The maximum storage duration from sampling to extraction was 109 days (3.6 months). All 

sample extracts were analyzed on the day of extraction. To support the residue trials, a 

concurrent storage stability study was conducted using control samples of peach fortified with 

thiacloprid, thiacloprid amide metabolite, and thiacloprid hydroxy amide metabolite at target 

level of 0.200 ppm. These samples were stored frozen (<-20oC) and then analyzed at 162 days 

with freshly fortified samples. The results show that residues of thiacloprid, thiacloprid amide 

metabolite, and thiacloprid hydroxy amide metabolite are stable in peach RAC for up to 162 days 

when stored frozen. 

Residues of thiacloprid ranged from 0.0305 ppm to 0.423 ppm on peaches harvested at a PHI of 

12-15 days and from <0.02 ppm to 0.359 ppm on peaches harvested at a PHI of 21-29 days 

following two foliar applications of Calypso 480SC at a total rate of 0.371-0.382 lb ai/A. The 

residue decline study showed that residues of thiacloprid on peaches declined over time. 

Plum: The IR-4 Project at Rutgers, The State University of New Jersey has submitted field trial 

data for thiacloprid in/on plums. Six field trials were conducted in the US during the 2001 

growing season in Zones 5 (MI, 1 trial), 10 (CA, 4 trials) and 12 (OR, 1 trial). One treated plot 

and one untreated control plot were established at each trial site. For each trial, two foliar 

applications of the test substance, Calypso 480SC (a suspension concentrate formulation 

containing 4 lb/gal of the active ingredient, thiacloprid), were made at a target rate of 0.125 lb 

ai/A for the first application and 0.250 lb ai/A for the second application, with retreatment 

intervals (RTIs) of 7-8 days. The total target application rate was 0.375 lb ai/A/season (~1x the 

proposed maximum seasonal rate of 0.38 lb ai/A). All applications were made using ground 

equipment at 44-263 GPA; no adjuvants were added to the spray mixtures. Samples of plums 

were harvested at PHIs of 14-15 days and 26-29 in all trials. At one trial site (01-MI19), samples 

were collected immediately after the application (0-day) and at PHIs of 7, 14, 28 and 33 days to 
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assess residue decline. At trial site 01-CA57, additional samples of plums were collected at PHIs 

of 15 and 29 days to determine the effect of drying the plums on thiacloprid residues. 

Residues of thiacloprid, thiacloprid amide metabolite, and thiacloprid hydroxyl amide metabolite 

were determined using the University of California, Davis working method derived from Bayer 

Ag. Draft Method, “Modified Residue Analytical Method for the Determination of YRC 2894, 

YRC 2894-Amide and 4-Hydroxy-YRC 2894-Amide Residue in Pecan Matrices” (April 8, 2001) 

with modifications. The lowest level of method validation (LLMV) for both plum RAC and 

dried plum was determined to be 0.020 ppm for each analyte. The limit of detection (LOD) was 

determined to be 0.004 ppm for thiacloprid and the amide metabolite in plum RAC samples, 

0.009 ppm for the hydroxy amide metabolite in plum RAC, 0.003 ppm for thiacloprid in dried 

plums, 0.005 ppm for the amide metabolite in dried plums and 0.01 ppm for the hydroxy amide 

metabolite in dried plums. The method is acceptable based on concurrent recoveries. 

The maximum storage duration from sampling to extraction was 176 days (5.8 months) for plum 

RAC and 133 days (4.4 months) for dried plums. All sample extracts were analyzed on the day 

of extraction. To support the residue data, a concurrent storage stability study was conducted 

using control samples of plums fortified with thiacloprid, thiacloprid amide metabolite, and 

thiacloprid hydroxy amide metabolite at target level of 0.20 ppm. These samples were stored 

frozen (<-20oC) and then analyzed at 161 days (plum RAC) and 120 days (dried plum) with 

freshly fortified samples. The results show that residues of thiacloprid, thiacloprid amide 

metabolite, and thiacloprid hydroxy amide metabolite are stable in plum RAC and dried plums 

for up to 161 and 120 days, respectively, when stored frozen. 

Residues of thiacloprid ranged from <0.020 ppm to 0.032 ppm in/on plum RAC harvested at 

PHIs of 14-15 days and 26-29 days following two foliar directed applications of thiacloprid at a 

total rate of 0.376-0.383 lb ai/A. Residues of the thiacloprid amide metabolite and thiacloprid 

hydroxy amide metabolite were all less than the LLMV (0.020 ppm). The residue decline study 

showed that residues of thiacloprid on plums declined over time. 

A summary of residue data from the representative commodities of Crop Group 12 is presented 

in Table 6. 

Table 6. Summary of Residue Data from Stone Fruit Crop Group 12 Field Trials with Thiacloprid.

Commodity Total Applic. Rate 

 (lb ai/A) 

PHI 

(days)

Residue Levels (ppm)

n Min. Max. HAFT Median 

(STMdR) 

Mean 

(STMR) 

Std. Dev.

Proposed use pattern: Foliar applications made at a single maximum of 0.25 lb ai/A/application, for a total of 0.38 lb 

ai/A/season; 14-day PHI 

Thiacloprid 

Sweet Cherry, fresh fruit 0.371-0.385 13-14 14 <0.02 0.263 0.239 0.176 0.163 0.072 

Peach, fresh fruit 0.371-0.382 12-15 18 0.031 0.423 0.369 0.126 0.167 0.121 

Plum, fresh fruit 0.375 14-15 12 <0.02 0.032 0.031 0.020 0.023 0.004 

Amide Metabolite 

Sweet Cherry, fresh fruit 0.371-0.385 13-14 14 <0.02 <0.02 <0.02 <0.02 <0.02 0.000 

Peach, fresh fruit 0.371-0.382 12-15 18 <0.02 <0.02 <0.02 <0.02 <0.02 0.000 

Plum, fresh fruit 0.375 14-15 12 <0.02 <0.02 <0.02 <0.02 <0.02 0.000 

Hydroxy Amide Metabolite 

Sweet Cherry, fresh fruit 0.371-0.385 13-14 14 <0.02 <0.02 <0.02 <0.02 <0.02 0.000 
Thiacloprid Summary of Analytical Chemistry and Residue Data DP#: D406397 

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Table 6. Summary of Residue Data from Stone Fruit Crop Group 12 Field Trials with Thiacloprid.

Commodity Total Applic. Rate 

 (lb ai/A) 

PHI 

(days)

Residue Levels (ppm)

n Min. Max. HAFT Median 

(STMdR) 

Mean 

(STMR) 

Std. Dev.

Peach, fresh fruit 0.371-0.382 12-15 18 <0.02 <0.02 <0.02 <0.02 <0.02 0.000 

Plum, fresh fruit 0.375 14-15 12 <0.02 <0.02 <0.02 <0.02 <0.02 0.000 

Conclusions for stone fruits. The submitted residue data for sweet cherry, peach, and plum, as 

representative crops of the stone fruit group (Crop Group 12), are adequate to fulfill data 

requirements. The number and location of cherry and plum crop field trials are in accordance 

with OPPTS Guideline 860.1500. For peaches, the locations of trials conducted according to the 

label are not in strict accordance with OPPTS Guideline 860.1500 due to issues with the 

application rates. Additional trials are not being requested. The total number of field trials is in 

accordance with the guideline. 

860.1520 Processed Food and Feed

Data depicting residues of thiacloprid in processed cherry, peach, and plum commodities were 

included in the residue field trial reports for each of these crops. Details of these studies can be 

found in Section 860.1500, above. Residues in processed commodities and the associated 

processing factors are summarized in Table 7. 

TABLE 7. Residue Data from the Processing Study with Thiacloprid.

Commodity Total Rate 

(lb ai/A) 

PHI 

(days) 

Residues (ppm, all as thiacloprid) Processing 

Factor1 Thiacloprid Amide Hydroxy Amide 

Cherry RAC 

0.397 14 

0.1525 <0.020 <0.020 NA 

Cherry (Washed) 0.1383 <0.020 <0.020 0.91x 

Cherry (Cooked) 0.1210 <0.020 <0.020 0.79x 

Cherry (Dried) 0.5483 <0.020 <0.020 3.6x 

Peach RAC 

0.3768 27 

0.0500 <0.020 <0.020 NA 

Peach (Washed) 0.0230 <0.020 <0.020 0.46x 

Peach (Cooked) <0.02 <0.020 <0.020 <0.40x 

Peach (Dried) 0.1793 <0.020 <0.020 3.6x 

Plum RAC 0.375 15 0.0228 <0.020 <0.020 NA 

Plum (Dried) 0.0465 <0.020 <0.020 2.0x 

Plum RAC 0.375 29 <0.02 <0.020 <0.020 NA 

Plum (Dried) 0.0618 <0.020 <0.020 3.1x 

LLMV = 0.020 ppm 

1

 Processing factors are calculated (by the reviewer) in terms of thiacloprid only by dividing the thiacloprid residues in each

processed fraction by the thiacloprid residues in the RAC. Reported residues are average values. 

Conclusions. The processing data satisfy requirements. The data indicate that residue levels are 

reduced in these fruits by washing and/or cooking, and that residues concentrate during the 

production of dried fruit. Based on the dried fruit concentration factor, the highest average field 

trial residues and the recommended tolerance levels, separate tolerances for dried commodities 

are not likely to be necessary. 

860.1850 Confined Accumulation in Rotational Crops 

Residue Chemistry Memo DP# 279818, 6/11/2003, D. Soderberg (PP#9F06060) 
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A confined rotational crop study was submitted and reviewed in PP#9F06060. The study was 

deemed adequate to satisfy data requirements provided the application rate use in the study is 

confirmed to approximate 1x. To date, the requested information has not been submitted. 

Based on the results of the confined accumulation study, limited field accumulation in rotational 

crop studies were required for wheat and for soybeans. Cotton may be planted at any time. 

Roots, tubers and bulb vegetables whose tops are not used for feed may be rotated with cotton 

after a PBI of 30 days. Leafy vegetables may be rotated after a 6-month PBI. Wheat, other 

grains, and vegetables other than those described above may not be planted in rotation until 

limited field accumulation in rotational crop studies are received for those crops. Studies were 

required for wheat and soybeans as stated above regardless of the PBI. 

The tolerance expression and/or the residues for risk assessment for rotational crops will be 

determined when field rotational crop studies become available. Based on information in the 

confined rotational crop studies, parent thiacloprid, YRC 2894 amide, and 4-OH-YRC 2894 

amide need to be measured in the edible portions of the rotated crops. The residues in various 

rotational crops consist of significant proportions of YRC 2894 amide, 4-OH-YRC 2894 amide, 

thiacloprid sulfonic acid and 6-picolinyl alcohol (6-CPA). The MARC had concluded that 6-

CPA and thiacloprid sulfonic acid can be neglected, but believes that actual field measurements 

of thiacloprid, YRC 2894 amide and 4-OH YRC 2894 amide are needed to establish the correct 

residues for risk assessment and any tolerance expressions that may be needed (D 288833, D. 

Soderberg, 7 April 2003). 

 

860.1900 Field Accumulation in Rotational Crops 

MRID Numbers 46677901 and 46677902 

Limited field accumulation studies in wheat and soybeans were required per previous HED 

review (11 June 2003, D279818, D. Soderberg) and have been submitted to the Agency (MRIDs 

46677901 and 46677902). An abbreviated review of these studies follows: 

Rotational crop field trials were conducted with soybean (MRID 46677901) and wheat (MRID 

46677902). Twenty trials were conducted for each crop and at each trial three broadcast spray 

applications were made to bare soil at a nominal rate of 0.095 lb a.i./A/application. 

Approximately 30 days after the last application, the soil was tilled and the soybean or wheat 

was planted. At maturity, crops were harvested for grain, forage, hay, and straw (wheat only). 

Samples were analyzed for residues of thiacloprid, thiacloprid amide, thiacloprid hydroxyamide, 

and thiacloprid sodium sulfonate. The sodium sulfonate does not contain an intact thiazolidine 

moiety,is not, therefore, a residue of concern, and is not discussed further in this review. The 

analytical method used solvent extraction (MeOH:H2O, 3:1, v:v), solid-phase clean up, and LCMS/MS separation and detection/quantitation. The method incorporated deuterated internal 

standards to aid in method performance. The LOQ of the method, defined as the lower limit of 

method validation, was 0.01 ppm for all analytes in all matrices. Method performance was 

satisfactory based on method validation and concurrent recovery results, and apparent residues 

were < LOQ in all control samples. 
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Residues of all analytes were < 0.01 ppm in all soybean matrices and wheat grain. Quantifiable 

residues of thiacloprid amide occurred in a few samples of wheat forage, hay, and straw. 

Residues of the hydroxyamide metabolite were < 0.01 ppm in all samples, except for three 

samples of wheat hay. Residues are summarized in Table 8. 

Table 8. Summary of Residue Data from Soybean and Wheat Rotational Crop Trials with Thiacloprid.

Commodity Total Applic. 

Rate 

 (lb ai/A) 

PBI 

(days) 

Residue Levels (ppm)

n Min. Max. HAFT Median 

(STMdR) 

Mean 

(STMR) 

Std. 

Dev. 

Thiacloprid 

Soybean, seed 0.285 30 20 <0.01 <0.01 <0.01 <0.01 <0.01 -- 

Soybean, forage 0.285 30 20 <0.01 <0.01 <0.01 <0.01 <0.01 -- 

Soybean, hay 0.285 30 20 <0.01 <0.01 <0.01 <0.01 <0.01 -- 

Wheat, grain 0.285 30 20 <0.01 <0.01 <0.01 <0.01 <0.01 -- 

Wheat, forage 0.285 30 20 <0.01 <0.01 <0.01 <0.01 <0.01 -- 

Wheat, hay 0.285 30 20 <0.01 <0.01 <0.01 <0.01 <0.01 -- 

Wheat, straw 0.285 30 20 <0.01 <0.01 <0.01 <0.01 <0.01 -- 

Amide Metabolite 

Soybean, seed 0.285 30 20 <0.01 <0.01 <0.01 <0.01 <0.01 -- 

Soybean, forage 0.285 30 20 <0.01 <0.01 <0.01 <0.01 <0.01 -- 

Soybean, hay 0.285 30 20 <0.01 <0.01 <0.01 <0.01 <0.01 -- 

Wheat, grain 0.285 30 20 <0.01 <0.01 <0.01 <0.01 <0.01 -- 

Wheat, forage 0.285 30 20 <0.01 0.030 0.030 0.01 0.011 0.004 

Wheat, hay 0.285 30 20 <0.01 0.035 0.032 0.010 0.014 0.007 

Wheat, straw 0.285 30 20 <0.01 <0.01 <0.01 <0.01 <0.01 -- 

Hydroxy Amide Metabolite 

Soybean, seed 0.285 30 20 <0.01 <0.01 <0.01 <0.01 <0.01 -- 

Soybean, forage 0.285 30 20 <0.01 <0.01 <0.01 <0.01 <0.01 -- 

Soybean, hay 0.285 30 20 <0.01 <0.01 <0.01 <0.01 <0.01 -- 

Wheat, grain 0.285 30 20 <0.01 <0.01 <0.01 <0.01 <0.01 -- 

Wheat, forage 0.285 30 20 <0.01 <0.01 <0.01 <0.01 <0.01 -- 

Wheat, hay 0.285 30 20 <0.01 0.019 0.017 0.01 0.010 0.001 

Wheat, straw 0.285 30 20 <0.01 <0.01 <0.01 <0.01 <0.01 -- 

Conclusions: Results indicate that tolerances for residues of thiacloprid are not needed for 

rotational crops. Similarly, residues in rotational crops are not a matter of concern for risk 

assessment. Residues were below the LOQ in all samples of human foods and should not 

significantly increase the total toxic residue when estimating the livestock dietary burden. The 

higher polarity of the metabolites relative to the parent compound indicates that these 

compounds are likely to be more readily excreted and further reduces the concern for human 

exposure via secondary residues in livestock commodities. 

860.1550 Proposed Tolerances

For purposes of tolerance expression, HED has determined that the residue of concern is the 

parent compound thiacloprid for all plant and animal commodities. Permanent tolerances are 

currently established for the combined residues of the insecticide thiacloprid and metabolites 

retaining the thiazolidine ring intact, measured and expressed in terms of thiacloprid, per se in/on 
Thiacloprid Summary of Analytical Chemistry and Residue Data DP#: D406397 

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various plant and animal commodities ranging from 0.02 ppm to 11 ppm [40 CFR §180.594]. 

The tolerance expression proposed by Bayer CropScience (PP#0E7706) for pepper (bell and 

non-bell) and IR-4 (PP#0F7704) for stone fruits are for the combined residues of the insecticide 

thiacloprid and metabolites retaining the thiazolidine ring intact, measured and expressed in 

terms of thiacloprid, per se. A revised Section F should be submitted, revising the tolerance 

definition to be in terms of only thiacloprid ([3-[(6-chloro-3-pyridinyl)methyl]-2-

thiazolidinylidene] cyanamide). The tolerance levels should also be revised to those listed in 

Table 8. 

Using the Agency’s Guidance for Setting Pesticide Tolerances Based on Field Trial Data, the 

recommended tolerance levels are 0.40 ppm for peppers, and 0.8 ppm for stone fruit, except 

plum and 0.04 ppm for plum (see Appendix I). There are currently no established Canadian, or 

Mexican maximum residue limits (MRLs) for thiacloprid in/on the proposed commodities. 

Codex MRLs have been established for residues of thiacloprid in/on sweet peppers (including 

pimento or pimiento) at 1 ppm and stone fruit, crop 12 at 0.5 ppm. Codex MRLs are expressed 

in terms of thiacloprid per se. Since the Codex MRLs are expressed on the same analytical basis 

as the recommended tolerance definition and the calculated tolerances are reasonably similar to 

the Codex MRLs (except plum), the U.S. tolerances, if established, should be harmonized with 

the Codex MRLs (see Table 9). A separate tolerance listing for plum will be necessary due to 

the significantly different residues in/on that fruit. An International Residue Limit (IRL) form is 

appended to this Summary Document and follows this section. 

Table 9. Tolerance Summary for Thiacloprid

Commodity Proposed Tolerance 

(ppm) 

Recommended Tolerance 

(ppm) 

Comments; Correct Commodity 

Definition

Pepper (bell and non-bell) 1.1 1.0 Pepper, recommended tolerance is 

harmonized with the Codex MRL. 

Stone Fruit, except plum 0.5 0.5 Fruit, stone, group 12, 

recommended tolerance is 

harmonized with the Codex MRL. 

Plum -- 0.05 Plum 
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International Residue Limits 

Thiacloprid (PC Code 014019; 9/16/2010) 

Summary of US and International Tolerances and Maximum Residue Limits 

Residue Definition: 

US Canada Mexico2 Codex3 

40 CFR 180.594: 

Plant/Livestock: thiacloprid ([3-[(6-

chloro-3-pyridinyl)methyl]-2-

thiazolidinylidene] cyanamide) and 

metabolites retaining the thiazolidine 

ring intact, measured and expressed in 

terms of thiacloprid, per se 

(Z )-[3-[6-chloro-3-

pyridinyl)methyl]-2-

thiazolidinylidene]cyana

mide, including 

metabolites retaining the 

thiazolidine ring intact 

Thiacloprid 

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

US Canada Mexico2 Codex 

Pepper (bell and non-bell) 

1.0 

 Peppers, 

Sweet 

(including 

pimento or 

pimiento) 1 

Fruit, stone, group 12, except 

plum 0.70 0.5 

Plum 0.05 

 

Completed: M. Negussie; 09/17/2010 

1

 Includes only commodities of interest for this action. Tolerance values should be the HED recommendations and 

not those proposed by the applicant. 

2 Mexico adopts US tolerances and/or Codex MRLs for its export purposes. 

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

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

fat portion of the sample. MRLs indicated as proposed have not been finalized by the CCPR and the CAC. 
Thiacloprid Summary of Analytical Chemistry and Residue Data DP#: D406397 

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Appendix 1 - Tolerance Assessment Calculations 

For each of the crops listed below, the OECD harmonized MRL Calculation Procedures were 

used to obtain a recommended tolerance. As per the policy for using the procedure, the average 

residue level from each field trial was used as input to obtain the recommended tolerance. 

PP#0E7706 

Pepper (Bell and Non-Bell)

The dataset used to obtain a tolerance recommendation for thiacloprid on pepper (bell and nonbell) consisted of field trial data representing application rates of 0.281-0.287 lb ai/A (3 

applications at ~0.094 lb ai/A/application) with PHIs of 6-7 days. As specified by the SOP, the 

trial application rates and PHIs are within 25% of the maximum label application rate and 

minimum label PHI, respectively. The residue values used to calculate the tolerance for bell and 

non-bell pepper are provided in the table below. 

All field trial sample results except for one sample of bell pepper were above the LOQ (LOQ = 

0.01 ppm); 4 of 6 field trial sample results for non-bell pepper were below LOQ (LOQ = 0.01 

ppm). 

Using the OECD harmonized MRL calculation procedures, the calculated tolerances are 0.30 

ppm for bell pepper and 0.6 ppm for non-bell pepper. Both values were flagged as having high 

uncertainty due to small data set. In addition, the non-bell pepper tolerance was flagged as being 

highly censored. The calculation-procedure-recommended tolerance for pepper is 0.60 ppm, the 

maximum of the recommended individual tolerances. The Codex MRL for peppers is 1.0 ppm. 

HED is recommending that the tolerance, if established, be set at 1.0 ppm in order to harmonize 

with Codex. 

PP#0E7704 

Stone Fruits, Crop Group 12

The dataset used to obtain a tolerance recommendation for thiacloprid on stone fruit consisted of 

field trial data for sweet cherry, peach, and plum (as representatives of crop group 12). The trials 

conducted reflect application rates of 0.371-0.385 lb ai/A (two applications at ~0.125 lb 

ai/A/application) with PHIs of 12-15 days. As specified by the SOP, the trial application rates 

and PHIs are within 25% of the maximum label application rate and minimum label PHI, 

respectively. The residue values that were entered into the tolerance spreadsheet are provided in 

the table below. 

All field trial sample results except for two samples of sweet cherry were above the LOQ (LOQ 

= 0.02 ppm). All field peach trial sample results were above the LOQ (LOQ = 0.02 ppm). 8 of 

12 field trial sample results for plum were below LOQ (67%). 
Thiacloprid Summary of Analytical Chemistry and Residue Data DP#: D406397 

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Using the OECD MRL harmonization procedures, the recommended tolerances are 0.50 ppm for 

cherry, 0.70 ppm for peach, and 0.05 ppm for plum. The disparity of approximately 10X 

between plum and the other representative commodities indicates that a separate tolerance for 

residues in/on plum is appropriate. The calculation-procedure-recommended tolerance for Crop 

Group 12, except plums is 0.70 ppm. This tolerance level recommendation is slightly higher 

than the level (0.5 ppm) proposed by the petitioner for Crop Group 12. The calculationprocedure-recommended tolerance for residues in/on plum is 0.05 ppm. The Codex MRL for 

stone fruit is 0.5 ppm. In order to harmonize with the Codex MRL, HED is recommending that 

the tolerance, if established, be set at 0.5 ppm for residues in/on fruit, stone, group 12, except 

plum. HED’s recommended tolerance level for residues in/on plum is 0.05 ppm. 
Thiacloprid Summary of Analytical Chemistry and Residue Data DP#: D406397 

 22 of 22Summary of the OECD MRL Calculation Procedure Inputs and Outputs for Thiacloprid in/on Peppers and Stone FruCompound Thiacloprid Thiacloprid Thiacloprid ThiacloprCrop Bell Pepper Non-Bell Pepper Sweet Cherry Peach Total number of data (n) 6 3 7 9 Percentage of censored data 17% 67% 14% 0% Number of non-censored data 5 1 6 9 Lowest residue 0.010 0.010 0.010 0.042 Highest residue 0.132 0.210 0.239 0.369 Median residue 0.040 0.010 0.176 0.125 Mean 0.053 0.077 0.162 0.167 Standard deviation (SD) 0.048 0.115 0.078 0.121 Correction factor for censoring (CF) 0.889 0.556 0.905 1.000 Proposed MRL estimate

- Highest residue 0.132 0.210 0.239 0.369 

- Mean + 4 SD 0.247 0.537 0.473 0.650 - CF x 3 Mean 0.142 0.128 0.440 0.500 Unrounded MRL 0.247 0.537 0.473 0.650 Rounded MRL 0.3 0.6 0.5 0.7 

High uncertainty of MRL estimate due to small dataset. 

High uncertainty of MRL estimate due to small dataset and high level of censoring. 

High uncertainty of MRL estimate due to small dataset. 

Residues 

(mg/kg) 

Residues 

(mg/kg) 

Residues 

(mg/kg) 

Residues 

(mg/kg) 

 0.0866 0.0100 * 0.2391 0.0418  0.0252 0.0100 * 0.1244 0.1231  0.0115 0.2096 0.0100 * 0.0649  0.0104 * 0.1649 0.1257  0.1324 0.2316 0.1881  0.0545 0.1878 0.3694  0.1762 0.1247  0.0974  0.3650