Page 1 of 30 UNITED STATES ENVIRONMEN TAL PROTECTION AGENCY WASHINGTON, DC 20460

OFFICE OF
CHEMICAL SAFETY AND
POLLUTION PREVENTION

MEMORANDUM

DATE: 2 November 2010

SUBJECT: Thiamethoxam. Petition to Esta blish Permanent Tolerances for Residues of the Insecticide Resulting from Food /Feed Use as a Seed Treatment on Peanuts and Alfalfa, and from Applications in Food-Handling Establishments. Summary of Analytic al Chemistry and Residue Data.

PC Code: 060109 DP Barcodes: D376367, D380653
Decision Numbers: 424517, 436785 File Symbol, Registration Numbers: 100-RGAL, 100-941, 100-1306
Petition Numbers: 9F7657, 0F7707, 0F7734 Regulatory Action: Amended Section 3 Risk Assessment Type: NA Case Number: NA

TXR Number: NA CAS Number: 153719-23-4
MRID #Numbers: See MRID Summary Table 40CFR: §180.565

FROM: William T. Drew, Chemist Risk Assessment Branch 2 (RAB2) Health Effects Division (HED), 7509P

THRU: Dennis McNeilly, Chemist Richard A. Loranger, PhD, Senior Scientist RAB2/HED, 7509P

TO: Kable Davis and Venus Eagle, RM Team 1 Insecticide/Rodenticide Branch (IRB) Registration Division (RD), 7505P

MRID Summary Table.

MRID
#Number Study Type Comments

45093704 860.1500 Crop Field Trials/Residue Decline New DER; peanut (nutmeat, hay).

860.1520 Processed Food and Feed New DER; peanut (meal, refined oil). 48020201 860.1500 Crop Field Trials/Residue Decline New DER; alfalfa (forage, hay). 48110202 Food-Handling Establishments New DER; spot, void, or crack and crevice treatment.Thiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 2 of 30 Executive Summary

Thiamethoxam (3-[(2-chloro-5-thia zolyl)methyl]tetrahydro-5-methyl- N -nitro-4 H -1,3,5- oxadiazin-4-imine) belongs to the pesticide chem ical class known as the neonicotinoids (Group 4A). It is a broad-spectrum, systemic insec ticide with activity against sucking and chewing insects on a wide variety of crops. It is also effective against a wide variety of interior and exterior pests, including termites, ants, beetles, and cockroaches. Syngenta Crop Protection submitted a petition to register a new use of thiamethoxam on peanuts (PP#9F7657). One end-use product (EP) rele vant to this petition is Cruiser PD (EPA File Symbol 100-RGAL), a wettable powder fo rmulation intended for dry-application seed treatment (WS), containing 70% of the active ingredient (ai), thiamethoxam. The other EP relevant to this petition is Cruiser 5FS (EPA Registration #10 0-941), a flowable concentrate formulation intended for seed treatment (FS), cont aining 5 pounds of ai per gallon (lb ai/gal). Both are proposed for pre-plan t seed treatment of peanuts at 0.20-0.29 mg ai/seed, to provide early season protection of seed lings against injury from thri ps, aphids, wireworms and white grubs, and suppression of three-co rnered alfalfa hoppers, and plant bugs. In conjunction with the proposed use, Syngenta has requested the establis hment of permanent tolerances for residues of thiamethoxam and its metabolite, CGA-322704 (clothia nidin), in or on peanut commodities, as
listed below.

Peanut ..........................................................................................0.05 ppm Peanut, hay ..................................................................................0.25 ppm

In support of the proposed registration and tolera nces, Syngenta submitted a magnitude of the residue study on peanut nutm eat and hay (MRID #45093704). The submitted peanut data are evaluated in this Summary Document. Syngenta also submitted a petition to regi ster a new use of thiamethoxam on alfalfa (PP#0F7707). The EP relevant to this petition is Cruiser 5FS (E PA Registration #100-941). It is proposed for pre-plant seed treatment of alfa lfa at 0.001 mg ai/seed, to provide early season protection of seedlings against damage caused by aphids and leafhoppers (fir st cut crop only). In conjunction with the proposed use, Syngenta ha s requested the estab lishment of permanent tolerances for residues of thiamethoxam and its metabolite, CGA-322704 (clothianidin), in/on alfalfa commodities, as listed below.

Alfalfa, forage .............................................................................0.05 ppm Alfalfa, hay ..................................................................................0.12 ppm

In support of the proposed registration and tolera nces, Syngenta submitted a magnitude of the residue study on alfalfa forage and hay (M RID #48020201). The submitted alfalfa data are evaluated in this Summary Document. Additionally, Syngenta submitted a petition to register a new food use of thiamethoxam in food handling establishments (PP#0F7734). The EP relevant to this pet ition is Optigard Flex Liquid (EPA Registration #100-1306), a suspension con centrate (SC) formula tion that contains 2Thiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 3 of 30 lb ai/gal. It is proposed for indoor spot, void, and crack and cr evice applications as 0.05 and 0.1% ai solutions, to control a wide variety of insect pests. In c onjunction with the proposed use, Syngenta has requested the establishment of a pe rmanent tolerance for residues of thiamethoxam and its metabolite, CGA-322704 (clothianidin), in/on f ood or feed commodities, as listed below.

Food commodities/feed commodities (other than those covered by a higher
tolerance as a result of use on growing crops) in food/feed handling establishments .............................................................................0.01 ppm

In support of the proposed registration and tole rance, Syngenta submitted a magnitude of the residue study on various food items following indoor applications in two different food handling establishments (MRID #48110202). The submitted food handling establishment data are evaluated in this Summary Document.
Tolerances for residues of thiamet hoxam are listed in 40CFR §180.565, and are expressed in terms of the combined residues of the insecticide thiamethoxam and its metabolite,
CGA-322704. The metabolite CGA-322704 is identical to the active ingred ient, clothianidin (PC Code 044309). The established tolerances in plant commodities, under 40CFR §180.565[a], range from 0.02 ppm to 4.5 ppm; about half of th e tolerances are set at the combined limit of quantitation (LOQ) for thiamethoxam and C GA-322704 of 0.02 ppm. Tolerances are also established under 40CFR §180.565[a] in livestock comm odities. The tolerances in milk and meat of cattle, goat, horse and sheep, and in meat and meat byproducts of hog, are set at 0.02 ppm each. The tolerances in meat byproducts of cat tle, goat, horse and sheep are set at 0.04 ppm
each. The nature of the residue in plants and an imals has been adequately delineated, based on metabolism studies with corn, cucumber, lettuce , pear, potato, rice, t obacco, wheat, goats and hens. The studies on corn, potato and wheat re flected seed treatment and/or soil drench applications. The residues of concern (ROCs), for the purposes of tolera nce expression and risk assessment, are the combined residu es of thiamethoxam and CGA-322704.
The nature of the residue in rotationa l crops is adequately understood. HED has determined (RAB2 continues to support the decisi on) that the major residu es from the confined rotational crop studies are the pa rent, thiamethoxam, and its CGA- 322704 metabolite. In animal feedstuffs, CGA-265307, a metabolite containing the N-nitro group, was found to be a major
residue. HED recommended that all three co mpounds be analyzed in field rotational crop
studies. Several field rotational crop studies on thiame thoxam are available. These data indicate that at an application rate of 0.179 pounds ai per acre (lb ai/A), roughly 1X the maximum
seasonal use rate of 0.188 lb ai/A on rotatable crops, quantifiable levels of thiamethoxam ROCs are not expected from a 120-day plantback interval (PBI). The proposed seed treatment use of
Cruiser PD and Cruiser 5FS on peanuts would result in a maxi mum per acre application rateThiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 4 of 30 equivalent to 0.08 lb ai/A (approximately 0.43X th e maximum use rate on rotatable crops), based on 850 seeds/lb, and a seeding (pla nting) rate of 142 pounds of seed s per acre (lb seeds/A). The proposed seed treatment use of Cruiser 5FS on alfa lfa would result in pe r acre applic ation rates equivalent to 0.0037-0.0130 lb ai/A (approxima tely 0.02-0.07X the maximum use rate on rotatable crops), depending on the se eding rate, in lb seeds/A. Novartis Analytical Method AG-675, a me thod utilizing high-performance liquid chromatography (HPLC) with ultraviolet (UV) or mass spectrometric (MS) detection, is the original enforcement method, and was submitted in conjunction with previous thiamethoxam petitions. Method AG-675 determines residue s of thiamethoxam and CGA-322704 in crop and livestock commodities. The method has undergone a successful independent laboratory validation (ILV), and Agency pet ition method validation (PMV). Following approval of Method AG-675 as an enforcement method, Syngenta submitted a
modification of the method to include a microwave ex traction step for liver. In its review of the modified Method AG-675, HED (D281702; M. Dohe rty; 17 April 2007) required that the method be completely rewritten to include the full residue extraction steps for both plant and livestock commodities. Syngenta responde d to this data gap by submitting Method GRM.009.04A (MRID #47786103), which supersed es Method AG-675. Method GRM.009.04A determines residues of parent thiame thoxam and its metabolites (CGA-322704 and CGA265307) individually using HPLC/UV for fruits, vege tables, oils, grains, and animal matrices other than liver. The LOQ for each analyte is 0. 010 ppm in all substrates except milk and fruit juices (0.005 ppm). The method includes a step inthe calculation to convert residues of CGA322704 to thiamethoxam equivalents. For analysis of cotton, tobacco, and the forage, fodder and straw of cereal grains, the method determines thiamethoxam ROCs using HPLC/MS, with an LOQ of 0.010 ppm in each analyte except grass (0.050 ppm). For analysis of liver, final residue determination is made using HPLC with tande m mass spectrometric detection (HPLC/MS/MS); the LOQ is 0.010 ppm each for thiamethoxam, CGA-322704 and CGA-265307. Syngenta also
submitted method validation data for Met hod GRM.009.04A (MRID #47786102). No ILV data have been submitted, nor will ILV data be require d, because the method is a revised version of an existing enforcement method. HED w ill forward Method GRM.009.04A (MRID #47786103) to FDA for an update of the thiamethoxam enforcement method in PAM Volume II. Samples of the peanut raw agricultural commodities (RACs), nutmeat and hay, were analyzed for residues of thiamethoxam and its metabolite, CGA-322704 (clothianidin), using Method AG-675 with either ultraviolet (HPLC/ UV), or tandem mass spectrometric detection (HPLC/MS/MS). This method is adequate for data collection, based on acceptable concurrent method recoveries. The LOQ was 0.01 ppm for each analyte, resul ting in an LOQ for combined residues of 0.02 ppm. Samples of the alfalfa RACs, forage and hay, were analyzed for residues of thiamethoxam and its metabolite, CGA-322704 (clo thianidin), using an HPLC/MS/MS method, Syngenta Analytical Method GRM009.02A. This method is also known as ADPEN Method M1104, and is adequate for data collection, base d on acceptable concurrent method recoveries. The LOQ was 0.01 ppm for each analyte, resultin g in an LOQ for combined residues of 0.02

ppm.Thiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 5 of 30 Samples of the various food commodities ut ilized in the food handling establishment study were analyzed for residues of thiamethoxam and its metabolite, CGA-322704 (clothianidin), via HPLC/MS/MS using Method AG-675. This method is adequate for data collection, based on acceptable concurrent method recoveries. The LOQ was 0.01 ppm for each analyte in all matrices, resulting in an LOQ for combined resi dues of 0.02 ppm. The FDA multiresidue methods (MRMs) of PAM Volume I are not adequate for tolerance enforcement, as thiamethoxam ROCs are not adequately recovered by any of the tested MRM protocols. Adequate storage stability data are available for thiamethoxam and CGA-322704 to support the storage conditions and durations of samples collecte d from the magnitude of the residue and food handling establis hment studies. There are no storage stability issues, and no corrections for potential decline during storage are needed for a ny of the residue studies. The submitted field trial data for thiamethoxam on peanuts are acceptable, and support the proposed use of Cruiser PD and Cruiser 5FS as pre-plant seed treatments. An adequate number of trials were conducted in the appr opriate geographic regions at roughly 1.5-3X the maximum proposed rate. Based on the maximu m combined thiamethoxam ROCs of 0.09 and 0.23 ppm in treated nutmeat and hay samples, respectively, HED concurs with the proposed tolerances of 0.05 ppm in peanut nut meat, and 0.25 ppm in peanut hay.
The submitted field trial data for thiamet hoxam on alfalfa are acceptable, and support the proposed use of Cruiser 5FS as a pre-plant seed treatment. An ad equate number of trials were conducted in the appropriate geogr aphic regions at 1X the maxi mum proposed rate. Based on
the maximum combined thiamethoxam ROCs of 0.04 and 0.10 ppm in treated forage and hay samples, respectively, HED concurs with the pro posed tolerances of 0.05 ppm in alfalfa forage, and 0.12 ppm in alfalfa hay.
The submitted data for thiamethoxam use in food handling areas are acceptable, and support the proposed use of Optigar d Flex Liquid as a spot, void, a nd crack and crevice treatment in food handling establishments. An adequate variety of food commodities were exposed to thiamethoxam, in two different types of food handling establishments, at 1X the maximum proposed rate. Maximum thiamethoxam a nd CGA-322704 residues were each <0.01 ppm in food commodities exposed to 1X treatment in f ood handling areas (with the vast majority of samples containing non-detectable residues). Based on the presen ce of detectable residues of thiamethoxam or CGA-322704 in various samples, HED recommends a tolerance of 0.02 ppm in food/feed commodities (other than those covere d by a higher tolerance as a result of use on growing crops). There are no processed commodities associated with the proposed use on alfalfa. The processed commodities associated with the propose d use on peanuts are peanut meal and refined oil. Two peanut field trials were conducted in the US during the 1999 growing season in which peanut seeds treated at an exaggerated (roughl y 6-6.5X) rate were grown for processing into peanut meal and refined oil. Thiamethoxam re sidues were not detected in the nutmeat nor processed fractions of peanuts grown from peanut seeds treated at the 6-6.5X rate. Residues were not detected in any of the peanut oil sa mples upon processing. Residues were observed in the nutmeat and meal of peanuts, grown from pe anut seeds treated at roughly a 2X rate, from
both field trials. The theoretical concentra tion factor for peanut meal (OPPTS ResidueThiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 6 of 30 Chemistry Test Guideline 860.1520, Table 3) is 2.2X . The empirical con centration factors for thiamethoxam in meal (range 2.0-3.1X, average 2 .6X) conform well to the theoretical value. A tolerance is not required in peanut oil. Based on the HAFT combined residues of 0.05 ppm (0.09 ppm at a 2X rate) in peanut nutmeat, and the theo retical concentration factor for peanut meal of 2.2X, HED recommends a tolerance of 0.15 ppm in peanut meal. Analytical reference standards for th iamethoxam and its metabolite, CGA-322704, are currently available at the EPA National Pesticide Standards Repository (NPSR).
There are no Codex or Mexican maximum resi due limits (MRLs) established for residues of thiamethoxam in crops associated with this review. Canada has established an MRL of 0.02 mg/kg for combined residues of thiamet hoxam and CGA-322704 in all food crops.

Regulatory Recommendations and Residue Chemistry Deficiencies

HED has examined the residue chemistry database for thiamethoxam. There are no residue chemistry issues that would preclude granting Section 3 registrations, and establishing permanent tolerances, for the requested use of thiamethoxam (as Cruiser PD or Cruiser 5FS) on peanuts, for the requested use (as Cruiser 5FS) on alfalfa, and for the requested use (as Optigard Flex Liquid) in food handling establishments. Pr ovided that the forthcoming human health risk assessment does not identify any issues of conc ern, the submitted data support tolerances for thiamethoxam, including its metabolites and degr adates, in or on peanut nutmeat, hay and meal, alfalfa forage and hay, and food/feed commod ities (other than those covered by a higher tolerance as a result of use on growing crops), at the levels listed below. Compliance with the tolerance levels specified below is to be determined by measuring only thiamethoxam and CGA322704 (calculated as thiamethoxam equivalents).

Peanut ..........................................................................................0.05 ppm Peanut, hay ..................................................................................0.25 ppm Peanut, meal ................................................................................0.15 ppm Alfalfa, forage .............................................................................0.05 ppm Alfalfa, hay ..................................................................................0.12 ppm
Food commodities/feed commodities (other than those covered by a higher
tolerance as a result of use on growing crops) in food/feed handling establishments .............................................................................0.02 ppm

A revised Section F should be submitted to reflect the additional tolerance in peanut meal, and the higher tolerance arising from the food/feed handling use. BackgroundThiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 7 of 30 Thiamethoxam is a broad-spectrum nitroguan idine insecticide which belongs to the pesticidal class of compounds known as the neonicot inoids (Group 4A). It has activity against sucking and chewing insects, such as leafhoppers and potato beetles, as well as other insect pests, on a wide variety of crops. It also is effective against a wide variety of interior and exterior pests, including termites, ants, be etles, and cockroaches. It appear s to interfere with the nicotinic acetylcholine receptors of the insect’s nervous sy stem, but the specific receptor site is unknown
at this time. It does not inhi bit cholinesterase, nor does it inte rfere with sodium channels, and
thus has a different mode of action than the organophosphate, carbamate and pyrethroid
insecticides. In support of a petition for use of th iamethoxam on peanuts (PP#9F7657), Syngenta submitted field trial data reflecting the seed trea tment use of thiamethoxam (70% ai WS, and 5 lb ai/gal FS) on peanuts. In support of a petiti on for use of thiamethoxa m on alfalfa (PP#0F7707), Syngenta submitted field trial data reflecting the s eed treatment use of thiamethoxam (5 lb ai/gal FS) on alfalfa. In support of a petition for use of thiamethoxam in food handling establishments (PP#0F7734), Syngenta submitted data reflecting spot , void, and crack and crevice applications of thiamethoxam (2 lb ai/gal SC) in food handlin g areas of a restaurant and a delicatessen. The
nomenclature of thiamethoxam and its metabolites , is summarized in Table 1 (below), and the physicochemical properties of the technical grade of thiamethoxam are summarized in Table 2 (below).

TABLE 1 Test Compound Nomenclature. Compound

Common name Thiamethoxam Company experimental

name CGA 293343

Molecular formula C 8 H 10 ClN 5 O 3 S Molecular weight 291.71 IUPAC name 3-(2-chloro-1,3-thiazol-5-ylmethyl)-5-methyl-1,3,5-oxadiazinan-4- ylidene(nitro)amine CAS name 3-[(2-chloro-5-thiazolyl)methyl]tetrahydro-5-methyl-N-nitro-4H-1,3,5-oxadiazin-4-
imine CAS registry number 153719-23-4 End-use products (EPs) 70% ai WS formulation (Cruiser PD Insecticide; EPA File Symbol 100-RGAL) 5 lb ai/gal FS formulation (Cruiser 5FS Insecticide; EPA Registration #100-941) 2 lb ai/gal SC formulation (Optigard Flex Liquid; EPA Registration #100-1306) N

O N N

C H

3

N S

Cl O 2 NThiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 8 of 30 TABLE 1 Test Compound Nomenclature.

Chemical structure of
CGA-322704 metabolite (clothianidin)

N-[(2-chloro-5-thiazoyl)methyl]-N’-methyl-N”-nitroguanidine

Chemical structure of
CGA-265307 metabolite

N-(2-chloro-thiazol-5-ylmethyl)-N’-nitroguanidine

TABLE 2 Physicochemical Properties of Technical Grade Thiamethoxam.

Parameter Value Reference* Melting point/range 139.1 ° C PMRA Regulatory Note (REG2001-03) on Thiamethoxam, 9 February

2001 pH 4.7 (1% solution in water) Density 1.57 x 10 3 kg/m 3
Water solubility 4.1 g/L (25°C) Solvent solubility Solvent

acetone dichloromethane ethyl acetate
hexane
methanol
octanol
toluene Solubility (g/L)

48
110
7.0 <1 mg/L

13
0.62
0.68 Vapor pressure 2.7 x 10 -9 Pa (20 ° C)

6.6 x 10 -9 Pa (25 ° C) Dissociation constant, pK

a No dissociation for pH range 2–12 Octanol/water partition coefficient, Log(K O W ) 0.13 ± 0.0017 (25 ° C)

UV/visible absorption spectrum Molar absorbance coefficients for the
absorbance maximum: 16,800 L/mol/cm at 255 nm (neutral) 17,000 L/mol/cm at 255 nm (acidic) 15,900 L/mol/cm at 255 nm (basic) (No further adsorption maxima between 290 and 750 nm were observed.) MRID #47287502

* As referenced in D349272; M. Doherty; 12 August 2008. N H N H N

C H

3

N S

Cl O 2 N

NH 2 NH

N N

S

Cl

NO 2Thiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 9 of 30 860.1200 Directions for Use

Peanuts: The EPs proposed for use on peanuts are Cruiser PD (EPA File Symbol 100- RGAL), a WS formulation of thiamethoxam containing 70% ai, and Cruiser 5FS (EPA Registration #100-941), an FS formulation of thia methoxam containing 5 lb ai/gal. They are proposed for use as pre-plant seed treatments of peanuts to provide ea rly season protection of seedlings against injury from thrips, aphids , wireworms and white grubs, and suppression of three-cornered alfalfa hoppers, and plant bugs. The proposed use directions on peanuts, obtained
from draft labels dated 7 December 2009 for Cruise r PD and Cruiser 5FS, are presented in Table 3 (below). In response to questions from HED, Syngent a clarified that the maximum use rate for peanuts should be 0.08 lb ai/A instead of 0.266 lb ai/A (electronic message of 18 October 2010, from Syngenta’s Patrick McCain to RD’s Kabl e Davis). This rate was calculated using assumptions which HED considers reasonable (850 seeds/lb, and 142 lb seeds/A). Alfalfa: The EP proposed for use on alfalfa is Cruiser 5FS (EPA Registration #100-941). It is proposed for use as a pre-pl ant seed treatment of alfalfa to provide early season protection of seedlings against damage caused by aphids and leafhoppers (first cut crop only). The proposed use directions on alfalfa, obtained from a draf t label dated 3 March 2010 for Cruiser 5FS, are presented in Table 3 (below). Food handling establishments: The EP proposed for use in food handling establishments is Optigard Flex Liquid (EPA Registration #100-1306), an SC formulation of thiamethoxam that contains 2 lb ai/gal. It is pr oposed for use as spot, void, and cr ack and crevice applications in food handling and other areas of food handling establishments. The proposed use directions for food handling establishments, obt ained from a draft label dated 10 June 2010 for Optigard Flex Liquid, are presented in Table 3 (below).

TABLE 3 Summary of Proposed Use Directions on Peanuts and Alflalfa, and in Food Handling
Establishments.

Use Timing;

Type; and Equipment Product [File Symbol or Registration

Number] Single

Use Rate Maximum Uses per
Season Maximum
Seasonal

Use Rate PHI (Days) Use Directions and
Limitations

Peanuts Pre-plant; seed

treatment. Cruiser PD [100-RGAL]
Cruiser 5FS

[100-941] 0.20-0.29

mg ai/seed 1 (Implied) 0.08
lb ai/A NS 1 No soil or foliar application of thiamethoxam to peanuts grown from seed treated with
Cruiser PD or Cruiser 5FS. Apply Cruiser PD in dry form, using equipment intended for dry-application seed treatment only (not for use in on-farm applicators; use in commercial seed treatment facilities only).Thiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 10 of 30 TABLE 3 Summary of Proposed Use Directions on Peanuts and Alflalfa, and in Food Handling
Establishments.

Use Timing;

Type; and Equipment Product [File Symbol or Registration

Number] Single

Use Rate Maximum Uses per
Season Maximum
Seasonal

Use Rate PHI (Days) Use Directions and
Limitations

Alflalfa Pre-plant; seed

treatment. Cruiser 5FS [100-941] 0.001 mg
ai/seed 1 (Implied) NS (0.0130) 2 NS No soil or foliar application of thiamethoxam to alfalfa grown
from seed treated with Cruiser

5FS. Food Handling Establishments Pest pressure;
coarse lowpressure spot spray, void injection, or
crack and crevice spray. Optigard Flex Liquid [100-1306] 0.05-
0.10%

spray NS NS NA 3 Prior to application, remove or
cover all food items in areas to be treated. Do not apply where
food utensils or food surfaces may become contaminated. Treatments to be made by commercial pesticide applicators only. 1. NS = Not Specified. 2. The alfalfa field trials utilized single (and seasonal) us e rates of 0.0037-0.0130 lb ai/A, based on the respective seeding rates (8.00-27.90 lb seeds/A), and an average of 210,000 alfalfa seeds/lb. 3. NA = Not Applicable.

Conclusion The submitted use directions for treatment of peanuts and alfalfa, and for applications in food handling establishments, are sufficient to a llow for evaluation of the submitted residue data relative to the proposed use patterns.

860.1300 Nature of the Residue - Plants Metabolism Decision Memo D258614; G.J. Herndon; 31August 1999 Residue Chemistry Memo D252021; G.J. Herndon; 30 March 2000 Residue Chemistry Memo D265079; G.J. Herndon; 8 May 2000 Residue Chemistry Memo D281702; M. Doherty; 17 April 2007

Plant metabolism studies with thiamethoxam have been submitted on corn, cucumber, lettuce, pear, potato, rice, tobacco and wheat. The studies on cucumber, lettuce, pear and rice reflected foliar applications, while the studies on corn, potato and wheat reflected seed treatment and/or soil drench applications. The tobacco studies included soil and foliar treatments. HED previously determined (and continues to support the decision) that the ROCs, for purposes of tolerance enforcement and risk assessment, ar e the combined residues of thiamethoxam and

CGA-322704.

860.1300 Nature of the Residue - LivestockThiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 11 of 30 Metabolism Decision Memo D258614; G.J. Herndon; 31August 1999 Residue Chemistry Memo D252021; G.J. Herndon; 30 March 2000 Residue Chemistry Memo D265079; G.J. Herndon; 8 May 2000

The nature of the residue in livestock is adequately understood, based on acceptable goat and hen metabolism studies. For purposes of to lerance enforcement and risk assessment, the
ROCs are the combined residues of thiamethoxam and CGA-322704.

860.1340 Residue Analytical Methods Residue Chemistry Memo D252021; G.J. Herndon; 30 March 2000 Residue Chemistry Memo D265079; G.J. Herndon; 8 May 2000 Residue Chemistry Memo D271516; M. Doherty; 29 May 2001 Residue Chemistry Memo D281702; M. Doherty; 17 April 2007

Enforcement Method
An HPLC method with UV or MS dete ction, Method AG-675, submitted in conjunction with previous thiamethoxam petitions, is adequate for collecting residue data, and enforcing tolerances for residues of thiamethoxam and CGA-322704 in crop and livestock commodities. The validated LOQ for each analyte is 0.010 ppm in all plant matrices, with the exception of fruit juices (0.005 ppm), grass (0.05 ppm) and cured tob acco (0.10 ppm). In livestock, the validated LOQs for residues of thiamethoxam and CGA- 322704 are 0.010 ppm for each analyte in meat, poultry and eggs, and 0.005 ppm each in milk. Briefly, samples are extracted with acetonitr ile (ACN)/water (4:1, volume to volume, or v/v), and the extract is subjected to partitioni ng with toluene and hexane (livestock commodity and oil samples only), and then cleaned up by solid-phase extraction (SPE). Residues of
thiamethoxam and CGA-322704 are determined in fru its, vegetables, oils, grains, and livestock commodities using HPLC/UV. HPLC/MS is used to determine residues in cotton commodities, tobacco commodities, and the forage, fodder and st raw of cereal grains and grasses to achieve the desired LOQs. The method in cludes a step in the calculati on to convert residues of CGA322704 to thiamethoxam equivalents. Adequate method validation data have been submitted, and the method has undergone a successful ILV and PMV. In addition, the met hod has been adequately radiovalidated in crop
and livestock commodities. Syngenta has submitted a re-written ve rsion of Method AG-675, and renamed it as Method GRM.009.04A (MRID #47786103), which s upersedes Method AG-675. The full extraction steps for plant and livestock commoditie s, including the microwave extraction step for liver, have been incorporated, as previously requested by HED as a condition of registration. The LOQs of Method GRM.009.04A have been established at 0.010 ppm each for residues of thiamethoxam, CGA-322704 and CGA-265307. Syngent a has submitted method validation data for Method GRM.009.04A (MRID #47786102). No ILV data have been submitted, nor will ILV data be required, because the method is a revi sed version of an existing enforcement method. Although the addition of a microw ave extraction step is a sign ificant change to the method, residues of thiamethoxam, CGA-322704 and CGA- 265307 are likely to be low in livestockThiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 12 of 30 commodities (the dosing levels used in the me tabolism studies were 100X for goats, and 400X for poultry). In addition, the extensive cleanup procedures after the microwave extraction step are very similar to the cleanup pr ocedures used for the Polytron extract of livestock commodity samples in Method AG-675, which has been ad equately validated by the Biological and Economic Analysis Division’s Analytical Chem istry Branch (BEAD/ACB). HED will forward MRID #47786103 to FDA for an update of the current method in PAM Volume II.

Data-collection methods

Peanuts: Novartis Analytical Method AG-675 was used to determine residues of thiamethoxam and its metabolite, CGA-322704, in peanut nutmeat, hay, meal and oil, with HPLC/UV, HPLC/MS and HPLC/MS/MS systems succe ssfully utilized to analyze the samples. The limits of detection (LODs), defined as the lowest mass injected th at could be reliably detected, were 1.25 ng for the HPLC/UV syst em, 0.125 ng for the HPLC/MS system, and 4 pg for the HPLC/MS/MS system. The LOQ, defined as the lowest recovery level analyzed in peanut samples, was 0.01 ppm for each analyte in all matrices, resulting in an LOQ for combined residues of 0.02 ppm. The analytical procedures that were used are summarized below. The majority of the peanut nutmeat samples were analyzed using HPLC/UV. Samples (10 grams) were extracted twice by polytron ho mogenization in ACN/water (4:1 v/v). The extraction volume was 200 mL, and a 50-mL aliquot was analyzed. The aliquot was evaporated to aqueous, and initially purifie d using reverse-phase (phenyl) SPE. After elution from the phenyl SPE column with methanol/water (1:1, v/ v), the sample was evaporated to aqueous, and partitioned with ethyl acetate. The ethyl acetat e fraction was evaporated, and further purified by normal-phase SPE, using a combination of ami no and alumina cartridge columns (the amino column was omitted in a few analytical sets with out affecting the results). The eluted sample was evaporated, and reconstituted in 1 mL of mobile phase (increased volumes were used as needed for larger compound concentrations). Analysis was performed using a normal-phase Spherisorb Amino HPLC column (250 mm lengt h x 4.6 mm ID), with a mobile phase of hexane/ethyl acetate/methanol/ isopropanol (11:3:1: 1, v/v). The analytes were detected using a wavelength of 255 nm. Peanut hay, and a few peanut nutmeat samp les, were analyzed using HPLC/MS/MS. Samples (10 grams) were extracted twice by polyt ron homogenization in ACN/water (4:1, v/v). The extraction volume was 200 mL, and a 50-mL a liquot was analyzed. Samples were first purified using a combination of anion-exchange (SAX) and reverse-phase (phenyl) SPE. After elution from the phenyl SPE column with methano l/water (1:1, v/v), the sample was evaporated to aqueous, and partitioned w ith ethyl acetate (a lthough some of the nutmeat samples were analyzed after elution from the phenyl SPE by ev aporating to aqueous, and diluting to final volume as described below). The ethyl acetate fraction was evaporated, and further purified by normal phase SPE using an alumina cartridge colu mn. The eluted sample was evaporated, and reconstituted in 30 mL of ACN/water (1:9, v/ v); increased volumes were used as needed for larger compound concentrations. Analysis was performed using a Phenomenex Luna 311 C 18 HPLC column (250 mm length x 2 .0 mm ID). The mobile phase was a gradient of ACN and water, each mixed with 0.1% acetic acid. Thia methoxam was detected by collision-induced dissociation (CID) of the parent ion (M+H + ion, m/z of 292), to form the daughter ion with m/z of 211.2. The m/z 211.2 daughter ion was used to detect and quantify thiamethoxam. TheThiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 13 of 30 metabolite, CGA-322704, was detected by CID of the parent ion (M+H + ion, m/z of 250), to form a daughter ion with m/z of 169. The m/z 16 9 daughter ion was used to detect and quantify

CGA-322704. Peanut meal samples were analyzed by HPLC /MS. Samples (10 grams) were extracted twice by polytron homogenization in ACN/water (4:1, v/v). The extr action volume was 200 mL, and a 50 mL aliquot was analyzed. The aliquot wa s evaporated to aqueous , and initially purified using reverse-phase (phenyl) SPE. After elution from the phenyl SPE column with methanol/water (1:1, v/v), the sample was evap orated to aqueous, and partitioned with ethyl acetate. The ethyl acetate fraction was evapor ated, and further purified by normal phase SPE using a combination of amino and alumina car tridge columns. The eluted sample was evaporated, and reconstituted in 1 mL ACN/water (1:9, v/v). Analysis was performed using a
Phenomenex Luna 311 C 18 HPLC column (250 mm length x 2.0 mm ID). The mobile phase was a gradient of ACN and water, each mixed with 0.1% acetic acid. Thiamethoxam was detected using the parent ion (M+H + ion, m/z of 292). The metabolite, CGA-322704, was detected using the parent ion (M+H + ion, m/z of 250). Peanut oil samples were analyzed by HPLC/U V. Samples (5 grams) were extracted by shaking in hexane, salt and toluene to form a 3- layer partition (aqueous in the bottom layer, ACN and toluene in the middle layer, and hexane in the top layer). The middle layer was isolated, evaporated, and initially purifie d using reverse-phase (phenyl) SPE. After elution from the phenyl SPE column with methanol/water (1:1, v/ v), the sample was evaporated to aqueous, and partitioned with ethyl acetate. The ethyl acetat e fraction was evaporated, and further purified by normal phase SPE, using a combination of amino and alumina cartridge columns. Oil samples were analyzed using the HPLC/U V system described above. The validity of the method for the an alysis of thiamethoxam and CGA-322704 in peanuts, peanut hay, peanut meal, and pea nut oil was demonstrated by including control (untreated) samples, and fortified control sample s along with each analytical sample set. The
fortification levels used for the concurrent recove ries were sufficient in magnitude to bracket the measured residue levels. The overall (all matric es, all fortification levels) average concurrent recoveries (± standard devi ation) were 91 ± 13% for thiamethoxam, and 89 ± 13% for CGA322704. Adequate sample calculations and ex ample chromatograms were provided. Where detected in control (untreated) samples, tota l thiamethoxam residues were below the LOQ. Alfalfa: Syngenta Analytical Method GRM009.02A was used to determine residues of thiamethoxam and its metabolite, CGA-322704, in alfalfa commodities. For forage analysis, approximately 10.0 gram s of sample were weighed into a widemouth bottle. The control samples used for procedural recoveries were fortified at the LOQ and higher to bracket the residues found in the treated samples. ACN/ water (4:1 v/v) was added (135 mL) to each sample, and then homogenized (using a Polytron homogenizer) for two minutes at 8,000-12,000 rpm. Subsequently, 20 mL of ACN/wate r (4:1 v/v) was used to rinse the rotating shaft of the Polytron, and then added to the sample bottle. The sample was allowed to settle for 3-5 minutes. A Whatman #5 filter was placed onto a Buchner funnel, and the funnel was positioned on top of a 250 mL side-arm flask. The solvent and any suspended material were decanted into a funnel, leaving the precipitate on the bottom of the bottle. A total of 35 mL of ACN/water (4:1 v/v) was used to rinse the samp le bottle, Buchner funnel, side-arm flask, andThiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 14 of 30 filter paper (20 mL to rinse out the sample bottle, and 15 mL to rinse out the side-arm flask). The sample was transferred to a 200 mL vol umetric flask, and diluted to 200 mL with ACN/water (4:1 v/v). An aliquot of 5 mL wa s placed into a 25 mL concentration tube, and concentrated in a nitrogen evaporator (at 35°C) to a volume of less than 2 mL. The sample was brought to a volume of 5 mL using ACN/water (1:9 v/v). The necessary dilutions were performed, and the samples were vialed for HPLC/MS/MS analysis. For hay analysis, approximately 5.0 grams of sample were weighed into a wide-mouth bottle. Control samples used fo r procedural recoveries were fo rtified at the LOQ and higher to
bracket the residues found in the treated samples. ACN/water (4 :1 v/v) was added (75 mL) to each sample, and then homogenized (using a Polytron homogenizer) for two minutes at 8,000- 1,2000 rpm. Subsequently, 10 mL of ACN/water (4:1 v/v) was used to rinse the rotating shaft of the Polytron, and then added to the sample bottle. The sample was allowed to settle for 3-5 minutes. A Whatman #5 filter was placed onto a Buchner funnel, and the funnel was positioned on top of a 250mL side-arm flask. The solvent a nd any suspended material were decanted into a funnel, leaving the precipitate on the bottom of th e bottle. A total of 15 mL of ACN/water (4:1 v/v) was used to rinse the sample bottle, Buchner funnel, side-arm flask, and filter paper (10 mL to rinse out the sample bottle, and 5 mL to ri nse out the side-arm flask). The sample was transferred to a 100 mL volumetric flask, and dilu ted to 100 mL with ACN/water (4:1 v/v). An aliquot of 5 mL was placed into a 25 mL concen tration tube, and concen trated in a nitrogen evaporator (at 35°C) to a volume of less than 2 mL. The sample was brought to a volume of 5 mL using ACN/water (1:9 v/v). The necessary d ilutions were performed, and the samples were vialed for HPLC/MS/MS analysis. Method validation was completed at three fortification levels for thiamethoxam and CGA-322704 prior to analysis of the field trial samples. The average recoveries of thiamethoxam from alfalfa forage at the L OQ (0.01 ppm), 2X LOQ a nd 10X LOQ were 77, 70 and 66%, respectively, whereas th e average recoveries from al falfa hay were 84, 117 and 95%, respectively. The average r ecoveries of CGA-322704 from alfa lfa forage at the LOQ (0.01 ppm), 2X LOQ and 10X LOQ were 79, 70 a nd 76%, respectively, whereas the average recoveries from alfalfa hay were 93, 96 and 89%, respectively. Ad equate sample calculations and example chromatograms were provided. In addition, the performance of the met hod was demonstrated by fortifying untreated control samples with thiamethoxam and CGA-3 22704 prior to extraction. These fortified samples were analyzed along with each analytical sample set. The overall (all fortification levels) average concurrent thiamethoxam recoveries (± standard deviation) were 95 ± 9% and 91 ± 15% from forage and hay, respectively. The overall average concurrent CGA-322704
recoveries were 85 ± 17% and 85 ± 17% from fora ge and hay, respectively. Recovery values were corrected for control residues, if any. Th e fortification levels us ed for the concurrent recoveries were sufficient in magnitude to bracket the measured residue levels. Food handling establishments: Samples of the various food commodities were analyzed using Novartis Analytical Method AG-675. Method modifications were issued 28 July 2008 to:

1. document apparatus that was removed from analysis, 2. document modifications to the method,Thiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 15 of 30 3. describe preparation of the calibration standard solutions, 4. identify the HPLC/MS/MS de tector used and provide the instrument conditions employed, and
5. describe the calculations used for residue determination.

To summarize the method, 10.0-gram sample s were extracted twice by homogenization in ACN/water (4:1, v/v). The extracts were co mbined, and brought to a final volume of 200 mL. A 20.0-mL aliquot was processed through a saltwater/toluene/hexan e/ACN liquid-liquid partition cleanup step, resulting in three layers:

1. a hexane layer (containing fats and oils), which was discarded, 2. an ACN/toluene layer, which was transferred to an evaporation flask, and 3. an aqueous layer, which was back -extracted with 2% toluene in ACN, and transferred to th e same evaporation flask containing the ACN/toluene layer.

The remaining organic layers we re combined, and concentrated to an aqueous remainder. Additional water, saturated with NaCl, was added to the concentrate. The analytes were then partitioned (two times) into ethyl acetate. The co mbined ethyl acetate extracts were evaporated to dryness, reconstituted in ethy l acetate/hexane (1:4, v/v), and subjected to amino SPE cleanup. The resulting eluate was evaporat ed to dryness. The sample was re-dissolved in 1 mL of HPLCgrade ACN, followed by 9 mL of HPLC-grade wate r, and then subjected to HPLC analysis. Final determination was by HPLC/MS/MS. Th e LOQ was 0.01 ppm fo r both analytes. The analytical method was validated using c ontrol samples of white bread, whole milk, butter, raw hamburger, and processed chicken prior to the analysis of food samples in this study. Triplicate samples were fortified with th iamethoxam and CGA322704 at the LOQ (0.010 ppm), and 10X LOQ (0.10 ppm). The analytical method wa s not validated in lettuce and apples as part of this study because these were matrices for which the method had been used previously. The performance of the method for determinati on of thiamethoxam and CGA322704 residues was also demonstrated by fortifying at least one unt reated control sample of each matrix with thiamethoxam and CGA322704 prior to extraction. These fortif ied samples were analyzed concurrently with each analytical sample set. All method recoveries, from both the method validation study, and the concurrent analysis of fortified sample s, were within the generally recognized acceptable range of 70-120%.Thiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 16 of 30 Conclusions The various data-collection methods, used for analysis of samples taken from the magnitude of the residue studies discussed in this summary document, are based on either Method AG-675 or Method GRM009.02A. The methods were deemed acceptable for use with all matrices analyzed in these studies. HED will forward Method GRM.009.04A (MRID #47786103) to FDA for an update of the thiamethoxa m enforcement method in PAM Volume II.

860.1360 Multiresidue Methods Residue Chemistry Memos D259838 and D259839; G.J. Herndon; 28 September 1999 Residue Chemistry Memo D252021; G.J. Herndon; 30 March 2000 FDA Pestrak Database; June 2005

The Agency has reviewed data concerning the recovery of resi dues of thiamethoxam using FDA MRM protocols of PAM Volume I. Thiamethoxam was partially recovered (50- 60%) using MRM Section 302 (Protocol D), but wa s not recovered using Sections 303 or 304 (Protocols E or F). Metabolites CGA-322704 an d CGA-265307 were tested using Protocol C, but did not yield adequate res ponses; no further testing was conducted for the metabolites. The results of the multiresidue testing were forwarded to FDA and ACB/BEAD.

860.1380 Storage Stability Residue Chemistry Memo D285545; M. Doherty; 6 November 2002 Residue Chemistry Memo D281702; M. Doherty; 17 April 2007

Samples in the peanut field trial and proces sing studies were stored frozen from sampling
to extraction for a maximum durati on of 5.1 months. Samples in th e alfalfa field trial study were stored frozen from sampling to extraction for a maximum duration of 15.9 months. Samples in the food handling establishment study were stored frozen from sampling to extraction for a
maximum duration of 2.6 months. Concurrent storage stability data were not submitted with these studies. However, the storage durations and conditions for samples from the current fi eld trial, processing, and food handling establishment studies are supported by pr eviously conducted storag e stability studies on diverse crops, and animal commodities. For plant commodities, adequate storage stabi lity data are available on five diverse crops.
These data indicate that resi dues of thiamethoxam and its metabolite, CGA-322704, are stable for up to approximately 24 months of frozen stor age (-18°C) in apple, tomato, potato, rapeseed, and corn grain (D281702; M. Doherty; 17 April 2007). In addition, residues of thiamethoxam
and CGA-322704 have been demonstrated to be rela tively stable in canola oil, corn meal, leaf lettuce, safflower seed, and tomato puree for up to roughly 40-42 months at -20°C. These data represent sufficiently diverse crops (a root crop, a leafy vegetable, a grain, an oilseed, a fruit, and a fruiting vegetable) to allow the determina tion that residues of thiamethoxam and CGA-322704 are stable in all crops for at least 24 months, a nd in associated processed commodities for at least
40 months.Thiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 17 of 30 For animal commodities, HED has review ed data indicating that residues of thiamethoxam, CGA-322704 and CGA-265307 are reasonabl y stable in eggs, milk, beef muscle, and beef liver for 15-17 months. In addition, residues of CGA-322704 have been demonstrated
to be stable in beef liver stor ed frozen for up to 47.7 months. Samples collected from the magnitude of the residue studies were st ored frozen prior to residue analysis. The storage durations and co nditions of samples are presented in Table 4 (below).

TABLE 4 Summary of Storage Conditions and Duration s of Samples from the Peanut, Alfalfa, and Food Handling Esta blishment Studies.

Matrix Storage Temperature (°C) Maximum Storage
Duration (Months) 1 Interval of Demonstrated Storage Stability (Months) 2

Peanut nutmeat -20 5.1 24 Peanut hay

Peanut meal 40

Peanut refined oil Alfalfa forage -10 15.9 24 Alfalfa hay

Butter <-10 2.6

Whole milk Raw hamburger Apple

Head lettuce

Processed chicken 2.6 40

White bread 1. Actual storage duration from harvest to extraction for analysis. 2. Thiamethoxam and CGA-322704 residues are relatively stable for up to 24 months in frozen RAC samples of apple, tomato, potato, rapeseed, leaf lettuce, and corn grain, and for up to 40 months in frozen processed commodity samples of corn meal, tomato puree, and canola oil (D281702; M. Doherty; 17 April 2007).

Conclusions The available storage stability data for th iamethoxam ROCs in plan ts are adequate to support the storage durations and conditions of sa mples of peanut and alfalfa commodities from the submitted field trial and processing studies . The submitted food handling establishment study is supported by the available storage stability data in plant and animal commodities. There are no storage stability issues, and no corrections for potential decline during storage are needed for any of the residue studies.

860.1400 Water, Fish, and Irrigated Crops

There are no proposed uses that are re levant to this gui deline topic. 860.1460 Food Handling DER for MRID #48110202 (Food handling esta blishment study with various food items)Thiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 18 of 30 TABLE 8 Summary of (1X) Residue Data from Un covered Foods Exposed to Thiamethoxam in the Food Handling Esta blishment Study. Commodity Total Use Rate (%ai, w/v) Sample Event (Hours) Thiamethoxam Levels (ppm)

n Min. Max. HA 1 Median Mean Std. Dev.

Butter 0.1 1 2 ND 2 ND ND ND ND NA 3

4 2 ND ND ND ND ND NA

8 2 ND ND ND ND ND NA

White bread 0.1 1 2 ND ND ND ND ND NA

4 2 ND ND ND ND ND NA

8 2 ND <0.01 <0.01 <0.01 <0.01 NA

Whole milk 0.1 1 2 ND ND ND ND ND NA

4 2 ND ND ND ND ND NA

8 2 ND ND ND ND ND NA

Raw hamburger 0.1 1 2 ND <0.01 <0.01 <0.01 <0.01 NA

4 2 ND ND ND ND ND NA

8 2 ND ND ND ND ND NA

Processed
chicken 0.1 1 2 ND ND ND ND ND NA

4 2 ND ND ND ND ND NA

8 2 ND ND ND ND ND NA Apple 0.1 1 2 ND ND ND ND ND NA

4 2 ND <0.01 <0.01 <0.01 <0.01 NA

8 2 ND <0.01 <0.01 <0.01 <0.01 NA

Head lettuce 0.1 1 2 ND <0.01 <0.01 <0.01 <0.01 NA

4 2 ND ND ND ND ND NA

8 2 ND ND ND ND ND NA 1. HA = Highest Average.
2. ND = Not Detected. 3. NA = Not Applicable (standard deviation is only applicable for sample sets of n ≥ 3 samples).

TABLE 9 Summary of (1X) Residue Data from Un covered Foods Exposed to Thiamethoxam in the Food Handling Esta blishment Study. Commodity Total Use Rate (%ai, w/v) Sample Event (Hours) CGA-322704 Levels (ppm)

n Min. Max. HA 1 Median Mean Std. Dev.

Butter 0.1 1 2 ND 2 ND ND ND ND NA 3

4 2 ND ND ND ND ND NA

8 2 ND ND ND ND ND NA

White bread 0.1 1 2 ND ND ND ND ND NA

4 2 ND ND ND ND ND NA

8 2 ND ND ND ND ND NA

Whole milk 0.1 1 2 ND ND ND ND ND NA

4 2 ND ND ND ND ND NA

8 2 ND <0.01 <0.01 <0.01 <0.01 NAThiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 19 of 30 TABLE 9 Summary of (1X) Residue Data from Un covered Foods Exposed to Thiamethoxam in the Food Handling Esta blishment Study. Commodity Total Use Rate (%ai, w/v) Sample Event (Hours) CGA-322704 Levels (ppm)

n Min. Max. HA 1 Median Mean Std. Dev.

Raw hamburger 0.1 1 2 ND <0.01 <0.01 <0.01 <0.01 NA

4 2 ND ND ND ND ND NA

8 2 ND ND ND ND ND NA

Processed
chicken 0.1 1 2 ND ND ND ND ND NA

4 2 ND ND ND ND ND NA

8 2 ND ND ND ND ND NA Apple 0.1 1 2 ND ND ND ND ND NA

4 2 ND ND ND ND ND NA

8 2 ND ND ND ND ND NA

Head lettuce 0.1 1 2 ND ND ND ND ND NA

4 2 ND ND ND ND ND NA

8 2 ND ND ND ND ND NA 1. HA = Highest Average.
2. ND = Not Detected. 3. NA = Not Applicable (standard deviation is only applicable for sample sets of n ≥ 3 samples).

A summary of the reviewed data from the food handling establishment study is presented in Tables 8 and 9 (above). The study was c onducted to determine the amount of thiamethoxam residues in food following indoor spot, and crac k and crevice treatments in a food handling establishment, using the 2 lb ai/gal SC formulation at the maximum proposed label rate. The study also provided information on the residues in food resulting from treatment at an exaggerated rate, in order to gauge the potential for misuse of the product. The study report
summarized residue data for thiamethoxam and its major metabolite, CGA322704 (clothianidin), in samples of foods typically used in 2 types of food handling establishments, including an oily food (butter), baked cereal product (bread), beve rage (milk), raw meat (hamburger), processed meat (chicken), fresh fruit (apple), and fresh vegetabl e (lettuce). Two types of food handling establishments (in which the principal business involved the preparation and sale of food di rectly to the consuming public) were used in the study. The establishments selected, a restaurant and a deli catessen, were typical of the expected product use
areas. Each establishment received an initial application of Optigard Fl ex Liquid at a dilution rate of 0.1% ai, weight to volume (ai, w/v), e qual to 16 mL (3.9 g ai) per gallon of finished solution, and a second application at 0.2% ai, w/v, equal to 32 mL (7.8 g ai) per gallon of finished solution. Two days elapsed between ap plications at each esta blishment. Crack and crevice, and spot treatments were made to the kitchen, storage and eating areas of each facility by a commercial licensed pest control operator. Crack and crevice trea tment included the lower portion of the walls, cabinets and areas where pest s may hide or enter a building. Spot treatment
included baseboard areas of the floor and walls th at did not exceed 2 square feet per spot (sq ft/spot). Foods that were used in the study represen ted the wide range of food items that are expected to be prepared and se rved in food service establishmen ts. A single control sample of each of the seven food types was collected at each establishment prior to th e 1X rate application.Thiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 20 of 30 Six replicates of each food type without any pack aging (uncovered), and six replicates of each food type that were covered, were placed on tables in the food preparation and serving areas (three replicates of each food type/coverage type in each area). Duplicat e samples of each food type/coverage type (one replicate from each of the two areas) were collected at 1, 4 and 8 hours following each application at each establishmen t. All samples were stored frozen after collection, and shipped frozen to Mors e Laboratories in Sacramento, CA. Samples were analyzed by Morse La boratories using Method AG-675. Final determination was by HPLC/MS/MS. The LOQ wa s 0.01 ppm for both analytes in all matrices, resulting in an LOQ for comb ined residues of 0.02 ppm. The first stage of sample analysis was focused on the uncovered food samples exposed for eight hours following the application of th e exaggerated (2X) use rate, which would be
considered the worst-case scenario for residues. The results of these an alyses (all residues were either non-detectable or <LOQ) led to the second stage, whic h was analysis of uncovered food samples only from each of the exposure intervals (1, 4 or 8 hours) following each application rate (1X or 2X). These data show ed that residues were not presen t at levels at or above the LOQ from any sampling event following either application rate.

Conclusions
The submitted data on thiamethoxam resi dues in food commodities following indoor spot, and crack and crevice treatments in food ha ndling establishments are adequate. The data reflect the use of the 2 lb ai/gal SC formula tion of thiamethoxam at 0.1% ai (w/v) and 0.2% ai (w/v). An acceptable method was used for the quantitation of thiamethoxam residues in the various food commodities, and adequate storage st ability data are available to support the sample storage durations and conditions. In addition, there were no thia methoxam residues detected at quantifiable levels in any of the wide variety of uncovered food types which were exposed for up to 8 hours to an exaggerated use pattern (1X rate, followed by 2X rate within 48 hours). Based on the presence of det ectable residues of thiamet hoxam or CGA-322704 in various samples, HED recommends a tolerance of 0.02 ppm in food/feed commodities (other than those covered by a higher tolerance as a re sult of use on growing crops).

860.1480 Meat, Milk, Poultry, and Eggs

The livestock feedstuffs associated w ith the proposed seed treatment uses of thiamethoxam on peanuts and alfalfa are peanut m eal and hay, and alfalfa forage, hay, meal and silage. These uses have the pot ential for exposing livestock to thiamethoxam residues in their diet. Secondary transfer of thiamethoxam ROCs to meat, milk, poultry and eggs is therefore possible from the proposed uses on peanuts and alfalfa. Ergo, reasonably balanced dietary burdens (RBDBs) were recalculated for the curren tly requested uses, and are presented in Table 5 (below).Thiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 21 of 30 TABLE 5 Calculation of Reasonably Balanced Di etary Burdens of Thiamethoxam Residues to
Livestock.

Feedstuff Type 1 % Dry

Matter 2 % Diet 2 Tolerance (ppm) Dietary Contribution (ppm) 3

Beef Cattle - R 15%, CC 80%, PC 5% Soybean hulls R 90 15 2.0 0.34 Potato processed waste CC 20 30 0.25 4 0.38 Barley grain CC 88 50 0.3 0.17 Soybean meal PC 88 5 0.02 5 0.0012

TOTAL BURDEN 100 0.90 Dairy Cattle - R 45%, CC 45%, PC 10%

Almond hulls R 90 10 1.2 0.14 Wheat forage R 25 20 0.5 0.4 Barley hay R 88 15 0.4 0.07 Barley grain CC 88 45 0.3 0.16

Undelinted cottonseed PC 88 10 0.1 0.012

TOTAL BURDEN 100 0.78 Poultry - CC 75%, PC 25% Barley grain CC 88 75 0.3 0.26

Alfalfa meal PC 89 5 0.12 0.007

Cottonseed meal PC 88 20 0.1 6 0.023

TOTAL BURDEN 100 0.29
Swine - CC 85%, PC 15% Barley grain CC 88 20 0.3 0.068 Field corn grain CC 88 65 0.02 0.015

Cottonseed meal PC 88 15 0.1 6 0.017

TOTAL BURDEN 100 0.10 1. R = Roughage, CC = Carbohydrate Concentrate, PC = Protein Concentrate. 2. OPPTS 860.1000 Table 1 Feedstuffs (June 2008). 3. Contribution = ([Tolerance / %DM] x %Diet) for beef and dairy cattle. Contribution = (Tolerance x %Diet) for poultry and swine. 4. Based on the 0.25 ppm potato tolerance. 5. Based on the 0.02 ppm soybean seed tolerance. 6. Based on the 0.1 ppm undelinted cottonseed tolerance.

Conclusions Because the projected thiamethoxam ROCs in poultry at the 1X f eeding level would still be <LOQ, HED concludes that residues in e ggs and poultry meat, fa t, and meat byproducts remain a 40CFR §180.6[a][3] situation (there is no expectation of fin ite residues in these commodities). As a result, tolerances are not required. This conclusion will be reevaluated when new poultry feed items are proposed in th e future. The RBDBs to cattle and swine have not increased significantly from those previously cal culated. Therefore, the current tolerances in livestock commodities remain appropriate, and do not need to be increased.Thiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 22 of 30 860.1500 Crop Field Trials DER for MRID #45093704 (Crop field trials with peanuts) DER for MRID #48020201 (Crop field trials with alfalfa)

TABLE 6 Summary of Residue Data from Pean ut Field Trials with Thiamethoxam.

Peanut
Matrix Use Rate (g ai/100 kg Seeds) EP Combined Residue Levels (ppm Thiamethoxam Equivalents) 1

n Min. Max. 2 HAFT 3 Mean Std. Dev. Hay 200 5FS 18 <0.02 0.06 0.05 0.026 0.011

70WS 36 <0.02 0.23 0.20 0.032 0.043

Nutmeat 5FS 18 <0.02 0.05 0.05 0.026 0.011

70WS 36 <0.02 0.04 0.03 0.021 0.004 Hay 600 70WS 4 <0.02 0.79 0.64 0.33 0.38

Nutmeat 4 <0.02 0.02 0.02 0.02 0 1. For calculation of the mean, HAFT, and standard deviation, the LOQ was used for residues reported as below the LOQ. 2. The table does not include the residue level in nutmeat used for the processing study. As noted in Section 860.1520, a RAC residue of 0.09 ppm was found in nutmeat following application at 200g ai/100 kg seeds (equivalent to 0.16 lb ai/A). 3. HAFT = Highest Average Field Trial.

Peanuts: A summary of the reviewed data from the peanut field trials is presented in Table 6 (above). Twelve peanut field trials were conducted in the US during the 1999 growing season. Each site consisted of one untreated plot, a nd at least one treated plot. At all trial sites, one treated plot was planted with peanut seeds that had been trea ted with an aqueous slurry of
the 70% ai WS formulation. At 3 sites, side-by-side trials were conducted, comparing the 70% ai WS product with the 5 lb ai /gal FS formulation. For both fo rmulations, peanut seeds were treated at the rate of 200 grams ai per 100 kg of seeds. Based on the amounts of seeds planted per acre, the rates were 0.126-0.24 lb ai/A (1.5- 3X the proposed maximum per-acre rate). The peanut crops were allowed to grow to comme rcial maturity according to good agricultural practices. Samples of nutmeat and hay were harv ested 101-153 days after planting (DAP). At 2 of the trial sites (in GA and TX), peanut seeds tr eated at an exaggerated rate (0.48-0.522 lb ai/A) were also grown, for processing into peanut meal and refined oil. Additionally, at 2 trial sites (in GA and TX) samples were harvested at 4 time interv als, in order to assess residue decline. Samples of the peanut RACs were analyzed for residues of thiamethoxam and its metabolite, CGA-322704 (clothianidin), using Me thod AG-675. This method is adequate for data collection, based on acceptable concurrent method recoveries. Th e LOQ was 0.01 ppm for each analyte matrices, resulting in an L OQ for combined residues of 0.02 ppm. In nutmeat, the highest individual residue was 0.04 ppm for thiamethoxam, and 0.01 ppm for CGA-322704, excluding the samples generated for processing. The nutmeat for processing, from an application rate of 0.16 lb ai/A, had total residues of 0.09 ppm. In hay, the highest individual residue was 0.19 ppm for thia methoxam, and 0.03 ppm for CGA-322704. A rate response was observed where exaggerated rates we re included. Residues following application of the 70% ai WS and 5 lb ai/gal FS formulati ons were similar in the side-by-side comparison trials. The magnitude of the residue is therefore unaffected by the choice of either formulation. Total residues in hay were observed to decline with time at one decline field trial, dropping fromThiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 23 of 30 a highest average residue of 0.04 ppm on day 111 (after planting of the treated seed) to 0.02 ppm on day 132. Total nutmeat residues from this fiel d trial increased from day 111 (highest average residue of 0.01 ppm) to day 118 (0.04 ppm), a nd subsequently declined to 0.01 ppm by day 132.
No decline was detected in the other decline field trial due to the low residues observed.

Conclusions The submitted peanut field trial data are adequate, and reflect the planting of peanut seeds
treated with either the 70% ai WS formulation, or the 5 lb ai/g al FS formulation of thiamethoxam at 200 g ai/100 kg seeds (0.126-0.24 lb ai/A, 1.5-3X the maximum pr oposed use rate). The study satisfied OPPTS Residue Chemistry Test Gu ideline 860.1500 (Tables 1 and 5) for number and geographic distribution of the tw elve field trial locations to determine the magnitude of the residues of thiamethoxam and its major meta bolite, CGA-322704 (clothianidin), in peanut RACs. An acceptable method was used for the quantitation of thiamethoxam residues in peanut nutmeat and hay, and adequate storage stability data are available to support sample storage
durations and conditions. Because a large percentage of the residue values were below the combined LOQ of 0.02 ppm, the tolerance harmonization spreadsheet was not used to determine an appropriate
tolerance. Based on the maximum combined thiamethoxam ROCs of 0.09 and 0.23 ppm in 1.5X- to 3X-treated nutmeat and hay samples, respectively, HED recommends a tolerance of 0.05 ppm in peanut nutmeat, and a tolera nce of 0.25 ppm in peanut hay.

TABLE 7 Summary of Residue Data from Alfa lfa Field Trials with Thiamethoxam.

Alfalfa Commodity Maximum

Use Rate 1 (lb ai/A) EP 2 Residue Levels (ppm)

Minimum Maximum HAFT 3

Thiamethoxam Forage 1st cutting 0.0130 Cruiser 5FS <0.01 0.03 0.03 Forage 2nd cutting <0.01 <0.01 <0.01 Forage 3rd cutting <0.01 <0.01 <0.01 Hay 1st cutting <0.01 0.09 0.08 Hay 2nd cutting <0.01 0.01 0.01 Hay 3rd cutting <0.01 <0.01 <0.01

CGA-322704 Forage 1st cutting 0.0130 Cruiser 5FS <0.01 <0.01 <0.01 Forage 2nd cutting <0.01 <0.01 <0.01 Forage 3rd cutting <0.01 <0.01 <0.01 Hay 1st cutting <0.01 <0.01 <0.01 Hay 2nd cutting <0.01 <0.01 <0.01 Hay 3rd cutting <0.01 <0.01 <0.01 1. The alfalfa field trials utilized single (and seasonal) us e rates of 0.0037-0.0130 lb ai/A, based on the respective seeding rates (8.00-27.90 lb seeds/A), and an average of 210,000 alfalfa seeds/lb.
2. EP = End-use Product. 3. HAFT = Highest Average Field Trial (average of duplicate measurements).

Alfalfa: A summary of the reviewed data from the alfalfa field trials is presented in Table 7 (above). Twelve alfalfa fi eld trials were conducted in the US during the 2008 and 2009Thiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 24 of 30 growing seasons. Each site cons isted of one untreated plot, and one treated plot. The treated plots were planted with alfalfa s eeds that had been treated with an aqueous slurry of the 5 lb ai/gal FS formulation, at the rate of 0.001 milligra ms of ai per seed (mg ai/seed). Based on seeding rates of 8.0 to 27.9 lb seeds/A, the appl ication rate is equivalent to 0.0037 to 0.0130 lb ai/A. The alfalfa crop was allowed to grow to commercial maturity according to good agricultural practices. Sample s of forage and hay were ha rvested at roughly 45 DAP (first cutting), 45 days after first cutting (second cutt ing), and 45 days after second cutting (third cutting) at all trial sites excep t one (in IA), where the third cu tting was not harvested. At one trial site (in CA), additional samples were harv ested at 24, 31, 38, and 52 DAP, in order to assess
residue decline. Samples of the RACs, alfalfa forage and hay, were analyzed for residues of thiamethoxam and its metabolite, CGA-322704 (c lothianidin), using Method GRM009.02A.
This method is also known as ADPEN Method M 1104, and is adequate for data collection, based on acceptable concurrent method recoveries. Th e LOQ was 0.01 ppm for each analyte, resulting in an LOQ for combined residues of 0.02 ppm.
The maximum residues of thiamethoxam and CGA-322704 were, respectively, 0.03 and <0.01 ppm in alfalfa forage grown from treated seed. The maximum residues of thiamethoxam and CGA-322704 were, respectively, 0.09 and <0.01 ppm in alfalfa hay grown from treated seed.
The maximum combined residues of thiame thoxam and CGA-322704 were 0.04 and 0.10 ppm in alfalfa forage and hay, respectively. In a ddition, residue decline data indicated that thiamethoxam residues in alfalfa forage decr eased from 0.16 ppm at 24 DAP to below the method LOQ (<0.01 ppm) at 52 DAP. The CGA- 322704 residues in alfalfa forage were <LOQ at all time points. Residue decline data indi cated that thiamethoxam residues in alfalfa hay decreased from 0.44 ppm at 24 DAP to below the method LOQ (<0.01 ppm) at 90 DAP (second cutting). The CGA-322704 residues in alfalfa hay were 0.02 ppm at 24 DAP, and <LOQ at all time points thereafter.

Conclusions The submitted alfalfa field trial data are adequate, and reflect the planting of alfalfa seeds
treated with the 5 lb ai/gal FS formulation of thiamethoxa m at 0.001 mg ai/seed, with harvest occurring at 45 DAP. The study satisfied O PPTS Residue Chemistry Test Guideline 860.1500 (Tables 1 and 5) for number and geographic distri bution of the twelve fi eld trial locations to determine the magnitude of the residues of thiamethoxam and its major metabolite, CGA-322704 (clothianidin), in alfalfa RACs. An acceptable method was used for the quantitation of thiamethoxam residues in alfalfa forage and hay, a nd adequate storage stability data are available to support sample storage dur ations and conditions. Because a large percentage of the residue values were below the combined LOQ of 0.02 ppm, the tolerance harmonization spreadsheet was not used to determine an appropriate
tolerance. Based on the maximum combined thiamethoxam ROCs of 0.04 and 0.10 ppm in 1Xtreated forage and hay samples, respectivel y, HED recommends a tolerance of 0.05 ppm in alfalfa forage, and a tolerance of 0.12 ppm in alfalfa hay.

860.1520 Processed Food and Feed DER for MRID #45093704 (Processed food/feed from peanuts)Thiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 25 of 30 There are no processed commodities associated with the proposed use on alfalfa. Two peanut field trials were conducted in the US during the 1999 growing season in which peanut seeds treated at exaggerated rates were grown for processing into peanut meal and
refined oil. Samples of the peanut RACs and processe d fractions were analyzed for residues of thiamethoxam and its metabolite, CGA-322704 (clothianidin), using Method AG-675 via HPLC/UV, HPLC/MS or HPLC/MS/MS. This met hod is adequate for data collection, based on acceptable concurrent method recoveries. Th e LOQ was 0.01 ppm for each analyte in all matrices, resulting in an LOQ for combined residues of 0.02 ppm.
Thiamethoxam residues were not detected in the nutmeat nor processed fractions of peanuts grown from peanut seeds treated at 0.48-0.522 lb ai/A (roughly 6-6.5X the proposed maximum use rate). Residues were not dete cted in any of the peanut oil samples upon processing. Reduction of thiamethoxam residues in peanut oil after processing was at least 0.22-
0.40X. Residues were observed in the nutmeat a nd meal of peanuts, grown from peanut seeds treated at 0.16-0.174 lb ai/A (rough ly 2X the proposed rate), from both field trials. The
theoretical concentratio n factor for peanut meal, presente d in OPPTS Residue Chemistry Test Guideline 860.1520, Table 3 (Theoretical Concen tration Factors Based upon Separation into Components), is 2.2X. The empirical concentra tion factors for thiamethoxam in meal (range 2.0-3.1X, average 2.6X) conform well to the theoretical value. A summary of the data from the peanut processing study is presented in Table 10 (below).

TABLE 10 Residue Data from Peanut Pro cessing Study with Thiamethoxam.

RAC Trial ID (Number County/State) Processed Commodity Total Rate (lb ai/A) PHI (Days) Residues (ppm) Processing

Factor

Peanut

Nutmeat 0S-SR-837-99
Turner/GA RAC 0.170-0.174 126 0.05 NA 1

Meal 0.10 2.0

Refined Oil <0.02 0.40 2

RAC 0.510-0.522 <0.02 NA

Meal <0.02 NC 3

Refined Oil <0.02 NC

0S-SR-309-99
Lavaca/TX RAC 0.160 132 0.09 NA

Meal 0.28 3.1

Refined Oil <0.02 0.22 2

RAC 0.480 <0.02 NA

Meal <0.02 NC

Refined Oil <0.02 NC 1. NA = Not Applicable. 2. Residues in oil were undetected; 0.02 ppm was used as the oil residue to calculate the processing factor. 3. NC = Not Calculable. Residues were undetected in RAC and processed fraction samples.

Conclusions A tolerance is not required in peanut oil. With HAFT combined residues of 0.05 ppm inThiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 26 of 30 peanut nutmeat (based on residues of 0.09 ppm at a 2X rate), and the th eoretical concentration factor for peanut meal of 2.2X, HED recommends a tolerance of 0.15 ppm in peanut meal.

860.1650 Submittal of Analytic al Reference Standards

Analytical reference standards for thiame thoxam (expiration date 30 August 2012) and its metabolite, CGA-322704 (expiration date 31 Augus t 2010, new standard on order) are currently available at the EPA’s NPSR, via personal co mmunication with Dallas Wright, of ACB, on 23 August 2010. Analytical reference standards should be replenished as requested by the Repository. The reference standard s should be sent to the ACB, wh ich is located at Fort Meade,
to the attention of Theresa Cole at the following address:

USEPA National Pesticide Standards Repository/Analytical Chemistry Branch/OPP 701 Mapes Road Fort George G. Meade, MD 20755-5350

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

860.1850 Confined Accumulation in Rotational Crops Metabolism Decision Memo D258614; G.J. Herndon; 31August 1999 Residue Chemistry Memo D252021; G.J. Herndon; 30 March 2000 (PP#9F5046) Residue Chemistry Memo D281702; M. Doherty; 17 April 2007

Confined rotational crop studi es were previously review ed in conjunction with the petition for thiamethoxam use on canola (PP#9F5046). These studies indicated that limited field rotational crop studies ar e necessary to support the proposed 120-day PBI for rotational crops, and that the metabolism of [ 14 C]-thiamethoxam in rotational crops is similar to the metabolism observed in primary crops. In a meeting held on 28 July 1999, HED determined that the major
residues from the confined rota tional crop studies were the pare nt thiamethoxam, and its CGA322704 metabolite. In some animal feedstu ffs, CGA-265307, a metabolite containing the Nnitro group, was found to be a major residue. HED recommended that all three compounds be analyzed in field rotational crop studies.Thiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 27 of 30 860.1900 Field Accumulation in Rotational Crops Residue Chemistry Memo D252021; G.J. Herndon; 30 March 2000 (PP#9F5046) Residue Chemistry Memo D281702; M. Doherty; 17 April 2007

Several field rotational crop studies on thia methoxam have been submitted and reviewed.
These data indicate that at an application rate of 0.179 lb ai/A (roughly 1X the maximum
seasonal use rate of 0.188 lb ai/A on rotatabl e crops), quantifiable residues of thiamethoxam ROCs are not expected from a 120-day PBI. Th e proposed maximum use rate of 0.08 lb ai/A in the petitions under review is well below the rate used in these studies.

860.1550 Proposed Tolerances

The submitted field trial data for thiamethoxam on peanuts are acceptable, and support the proposed use of Cruiser PD and Cruiser 5FS as pre-plant seed treatments. An adequate number of trials were conducted in the appr opriate geographic regions at roughly 1.5-3X the maximum proposed rate. Based on the maximu m combined thiamethoxam ROCs of 0.09 and 0.23 ppm in treated nutmeat and hay samples, respectively, HED recommends a tolerance of 0.05 ppm in peanut nutmeat, and a tolera nce of 0.25 ppm in peanut hay.
The submitted field trial data for thiamet hoxam on alfalfa are acceptable, and support the proposed use of Cruiser 5FS as a pre-plant seed treatment. An ad equate number of trials were conducted in the appropriate geogr aphic regions at 1X the maxi mum proposed rate. Based on
the maximum combined thiamethoxam ROCs of 0.04 and 0.10 ppm in 1X-treated forage and hay samples, respectively, HED recommends a tole rance of 0.05 ppm in alfalfa forage, and a tolerance of 0.12 ppm in alfalfa hay.
The submitted data for thiamethoxam use in food handling areas are acceptable, and support the proposed use of Optigar d Flex Liquid as a spot, void, a nd crack and crevice treatment in food handling establishments. An adequate variety of food commodities were exposed to thiamethoxam, in two different types of food handling establishments, at 1X the maximum proposed rate. Based on the presence of det ectable residues of thiamethoxam or CGA-322704 in various samples, HED recommends a toleran ce of 0.02 ppm in food/feed commodities (other than those covered by a highe r tolerance as a result of use on growing crops). There are no processed commodities associated with the proposed use on alfalfa. The processed commodities associated with the propose d use on peanuts are peanut meal and refined oil. Two peanut field trials were conducted in the US during the 1999 growing season in which peanut seeds treated at exaggerated (roughly 6-6.5X ) rates were grown for processing into peanut
meal and refined oil. Thiamethoxam residues we re not detected in the nutmeat nor processed fractions of peanuts grown from peanut seeds treated at 6-6.5X rates. Residues were not detected in any of the peanut oil samples upon processing. Residues were observed in the nutmeat and meal of peanuts, grown from peanut seeds treated at the 2X rate, from both field
trials. The theoretical concen tration factor for peanut meal (OPPTS Residue Chemistry Test Guideline 860.1520, Table 3) is 2.2X. The empiri cal concentration factors for thiamethoxam in meal (range 2.0-3.1X, average 2.6X) conform well to the theoretical value. A tolerance is notThiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 28 of 30 required in peanut oil. Based on the HAFT co mbined residues of 0.05 ppm in peanut nutmeat (based on residues of 0.09 ppm at a 2X rate), and the theoretical concentration factor for peanut meal of 2.2X, HED recommends a tole rance of 0.15 ppm in peanut meal.
There are no Codex or Mexican MRLs estab lished for residues of thiamethoxam in crops
associated with this review. Canada has es tablished an MRL of 0.02 mg/kg for residues of thiamethoxam and CGA-322704 in all food crops, and is transitioning to specific commodity MRLs (all at 0.02 mg/kg) on a variety of crops in cluding various cereal grains, peas and beans, soybeans, sweet corn, and sunflower.

TABLE 11 Tolerance Summary for Thiamethoxam. Commodity Proposed/Established Tolerance (ppm) Recommended Tolerance (ppm) Comments; Correct Commodity Definition

Peanut 0.05 0.05 Peanut, hay 0.25 0.25 Peanut, meal None 0.15 Alfalfa, forage 0.05 0.05 Alfalfa, hay 0.12 0.12 Food/feed commodities (other than those covered by a higher
tolerance as a result of use on growing crops) 0.01 0.02

References

Thiamethoxam. Results of the HED Met abolism Assessment Review Committee Meeting
Held on 7/28/99. ; D258614; G.J. Herndon; 31 August 1999.

Multi-Residue Method Testing of Thia methoxam (CGA-293343) and Its Metabolite ; D259838; G.J. Herndon; 28 September 1999.

Multiresidue Test informa tion for the updating of PAM I; D259839; G.J. Herndon; 28 September 1999.

PP#9F5046. Thiamethoxam on Canola. Section 3 Registration and Permanent Tolerance Request for Use of Thiamethoxam (He lix Formulation) for Use as a Seed Treatment on Canola Seed Prior to Planting. First Food Use. Residue Chemistry Review: Evaluation of Analytical Method and Residue Data. ; D252021; G.J. Herndon; 30 March 2000.

PP#9F5051. Thiamethoxam on Various Crops. Section 3 Registration and Permanent Tolerance Request for Use of Thiamethoxam as a Seed Treatment, Soil Treatment, or Foliar Use on Barley, Brassica (Cole) Leafy Vegetables, Cotton, Cucurbit Vegetables, Fruiting (except Cucurbit) Vegetables, Leafy (except Brassica) Ve getables, Pome Fruit, Tuberous and Corm Vegetables, Sorghum, and Wheat. Section 3 Re gistration for Tobacco. Residue ChemistryThiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 29 of 30 Review: Evaluation of Analyt ical Method and Residue Data. ; D265079; G.J. Herndon; 8 May

2000.

PP#95046/95051. Thiamethoxam on Canola, Barley, Sorghum, Wheat, Cotton, Tuberous and Corm Vegetables, Leafy Vegetables, Brassica Vegetables, Fruiting Vegetables, Cucurbit Vegetables, Pome Fruits, and Tobacco. Results of Petition Method Validation. ; D271516; M. Doherty; 29 May 2001.

PP#0F06142. Thiamethoxam. Section 3 Registration for Use as a Corn Seed Treatment. Summary of Analytical Chemistry and Residue Data. ; D285545; M. Doherty; 6 November 2002.

PP#3E6524, 2E6505, 1E6349, 2E6508. Thiamethoxam. Section 3 Registration for Use on Stone Fruit, Coffee, Pecan, and as a Seed Treatment on Sunflower and Succulent Beans. Summary of Analytical Chemistry and Resi due Data.; D286726; Y. Donovan; 23 December

2003.

Thiamethoxam. Summary of Analytical Chemistry and Residue Data. PP#0F6142. Request for Amended Use Patte rns for Actara® Insecticide (EPA Reg. No. 100-938), Centric® 40WG Insecticide (EPA Reg. No. 100-1147), and Pl atinum® Insecticide (EPA Reg. No. 100-939) and to Register Actara® 240 SC Insecticide (File Symbol No. 100-RELN). PP#6E7060. IR-4 Request to Add Uses on Artichoke, Barley, and C aneberry to Actara® Insecticide (EPA Reg. No. 100-939) and Uses on Hops to Platinum® Insecticide (EPA Reg. No. 100-939). PP#s3E6805, 9F5051, 3E6806, 3E6781, 2E6363, 3E6800, 3E6807, 4E6819, and 04CA0015. Section 3 Registration for Seed Treatment Uses on Legume Vegetables, Potato Seed Pieces, Oilseed Crops; and Foliar Uses on Cranberry, Mint, Stra wberry, Bushberry, and Root Vegetables (Except Sugarbeet); and the Section 18 Emergency Exemption on Artichoke. ; D281702, D325447, D335847, D292865, D296610, D297966, D298143, D298157 & D300775; M. Doherty; 17 April 2007.

PP# 0F6142. Thiamethoxam. Request to Add Foliar Treatment of Soybeans to the Label for Centric® WG Insecticide. Summary of Analytical Chemistry and Residue Data. ; D346216; M. Doherty; 13 November 2007.

Thiamethoxam. Application for Amended Sect ion 3 Registration to Add Uses on Citrus Fruit Group 10 and Tree Nut Group 14. Summary of Analytical Chemistry and Residue Data. ; D349272; M. Doherty; 8/12 August 2008.

Attachment: International Residue Limit Status sheet.Thiamethoxam Summary of Analytical Chem istry and Residue Da ta D376367, D380653

Page 30 of 30 

## INTERNATIONAL RESIDUE LIMIT STATUS

CAS Name: 3-[(2-chloro-5- thiazolyl) methyl]tetrahydro-5-methyl-N-nitro-4H-1,3,5-oxadiazin4-imine. Common Name:
Thiamethoxam. X Recommended tolerance

⁮ Reevaluated tolerance

⁮ Other Date:
2 August 2010

Codex Status (Maximum Residue Limits) US Tolerances
X No Codex proposal step 6 or above

□ No Codex proposal step 6 or above for the crops requested Petition Numbers: 9F7657, 0F7707, 0F7734 DP Barcodes: D376367, D380653
Other Identifier: PC Code 060109 Residue definition (step 8/CXL): Not applicable. Reviewer/Branch: William T. Drew/RAB2

Residue definition: Combined residues of the insecticide thiamethoxam [3-[(2-chloro-5-thiazolyl) methyl]tetrahydro-5-methyl-N-nitro-4H-1,3,5-oxadiazin-4-imine] and its metabolite [N-(2-chlorothiazol-5-ylmethyl)-N’-methyl-N’-nitro-guanidine].
Crop(s) MRL (mg/kg) Crop Tolerance (ppm)

Peanut 0.10 Peanut, hay 0.25
Peanut, meal 0.15 Alfalfa, forage 0.05 Alfalfa, hay 0.12 Food/feed commodities (other than those covered by a higher tolerance as a result of use on growing crops) 0.01

Limits for Canada 1 Limits for Mexico 2

⁮ No Limits

⁮ No Limits for the crops requested ⁮ No Limits X No Limits for the crops requested Residue definition: 3-[(2-chloro-5-thiazolyl) methyl]tetrahydro-5-methyl- N -nitro-4 H -1,3,5- oxadiazin-4-imine,including the metabolite ( E )- N -[(2-chloro-5-th iazolyl)methyl]- N'
- methyl- N" -nitro-guanidine. Residue definition: Thiamethoxam.

Crop(s) MRL (mg/kg) Crop(s) MRL (mg/kg)

Alfalfa 0.02

Peanut 0.02

Notes and/or special instructions: 1. Includes only commodities of interest for this action. 2. Mexico adopts US tolerances and/or Codex MRLs for its export purposes. (Steve Funk/Meheret Negussie)