Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

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Potato ..........................................................................0.03 ppm

Onion, bulb ...................................................................1.0 ppm

Onion, green..................................................................7.5 ppm

Vegetable, fruiting, group 8, except tomato..................2.0 ppm

Tomato ..........................................................................0.2 ppm

Fruit, citrus, group 10..................................................10.0 ppm

Caneberry subgroup 13-A.............................................5.0 ppm

Bushberry subgroup 13-B .............................................3.0 ppm

Grape.............................................................................1.0 ppm

Strawberry...................................................................10.0 ppm

Juneberry.......................................................................3.0 ppm

Lingonberry...................................................................3.0 ppm

Salal...............................................................................3.0 ppm

Cotton, undelinted seed.................................................0.6 ppm

Canola, seed ..................................................................1.0 ppm

Sunflower, seed.............................................................0.5 ppm

Crambe, seed.................................................................0.5 ppm

Flax, seed ......................................................................0.5 ppm

Rapeseed, seed ..............................................................0.5 ppm

Rapeseed, Indian ...........................................................0.5 ppm

Mustard, field, seed.......................................................0.5 ppm

Mustard, Indian, seed....................................................0.5 ppm

Safflower, seed..............................................................0.5 ppm

Under PP#1E7851, IR-4, on behalf of the Agricultural Experiment Stations, is requesting use of 

azoxystrobin, difenoconazole, or the three-way mixture of azoxystrobin + difenoconazole +

fludioxonil on tuberous and corm vegetables subgroup 1C as a postharvest treatment. Syngenta 

Crop Protection, Inc. (Syngenta) submitted residue data for difenoconazole, azoxystrobin, and 

fludioxonil on potatoes following postharvest treatment. The subject review addresses the 

adequacy of the magnitude of the residues of azoxystrobin and the Z-isomer (R230310) only; 

difenoconazole and fludioxonil results are reported in separate DERs.

In addition, Syngenta has requested amendment of the product label for Abound® Flowable 

Fungicide (EPA Reg. No. 100-1098), an SC formulation containing 22.9% ai (2.08 lb ai/gal) 

azoxystrobin, to add uses on tuberous and corm vegetables subgroup 1C as a postharvest 

treatment, dragon fruit, and wasabi. The petitioner has also requested amendment of the labels 

for Abound® Flowable Fungicide (EPA Reg. No. 100-1098), Quilt® (EPA Reg. No. 100-1178), 

Graduate A+TM (EPA Reg. No. 100-1308), Quadris TopTM (EPA Reg. No. 100-1313), Quilt 

XcelTM (EPA Reg. No. 100-1324), and azoxystrobin dry technical manufacturing use concentrate 

(EPA Reg. No. 100-1120) to incorporate the crop group/subgroup or representative commodity 

expansions.

Azoxystrobin tolerances have been established in 40 CFR §180.507. Tolerances for crop

commodities are listed in 40 CFR §180.507(a)(1) and are expressed in terms of residues of the 

fungicide azoxystrobin and the Z-isomer of azoxystrobin. Tolerances are currently established for 

azoxystrobin in/on various plant commodities at levels ranging from 0.01 ppm in/on pecans and to 

420 ppm in/on aspirated grain fractions.
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

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Tolerances for livestock commodities are listed in 40 CFR §180.507(a)(2) and are expressed in 

terms of residues of azoxystrobin and its Z-isomer; the Z-isomer should be removed from the 

tolerance expression. The established tolerances for livestock commodities range from 0.006 

ppm for milk to 0.07 ppm for the meat byproducts of cattle, goat, horse, and sheep; no tolerances 

are currently established for poultry commodities.

The existing established tolerances on onion, bulb (1.0 ppm) (for onion, bulb subgroup 3-07A); 

onion, green (7.5 ppm) (for onion, bulb subgroup 3-07B); tomato (0.2 ppm) (for tomato subgroup 

8-10A); vegetable, fruiting, group 8, except tomato (2.0 ppm) (for pepper/eggplant subgroup 8-

10B); fruit, citrus, group 10 (10.0 ppm) (for fruit, citrus, group 10-10); caneberry subgroup 13A 

(5 ppm) (for caneberry subgroup 13-07A); bushberry subgroup 13-07B (3.0 ppm) and juneberry, 

lingonberry, and salal (3.0 ppm) (for bushberry subgroup 13-07B); grape (1.0 ppm) (for fruit, 

small vine climbing, except fuzzy kiwifruit, subgroup 13-07F); strawberry (10.0 ppm) (for berry, 

low growing, subgroup 13-07G, except cranberry); canola seed (1.0 ppm) (for rapeseed subgroup 

20A); safflower, seed and sunflower, seed (0.5 ppm) (for sunflower subgroup 20B); and cotton,

undelinted seed (0.6 ppm) (for cottonseed subgroup 20C) were used to establish the proposed 

tolerances. The proposed tolerance changes are a result of revisions in the crop groups and are 

conversions from existing groups/subgroups or representative commodities. The proposed 

tolerances for the dragon fruit and wasabi are extrapolated from existing azoxystrobin tolerances 

on mango (2.0 ppm) and the herb subgroup 19A, fresh leaves (50 ppm), respectively. HED 

concludes that the available data on these commodities and/or crop groups/subgroups are

adequate to establish the tolerances on the proposed crop groups/subgroups. No new residue data 

are submitted or are needed for these changes. 

The nature of the residue in plants, rotational crops, and livestock is adequately understood. 

Acceptable metabolism studies have been conducted on primary crops of grapes, peanuts, and 

wheat as well as on representative rotational crops. Acceptable metabolism studies on goats and 

laying hens are also available. The residues of concern in/on primary and rotational crop 

commodities, for tolerance expression and risk assessment purposes, are azoxystrobin and its Zisomer. The residue of concern in livestock is parent azoxystrobin only.

Adequate residue analytical methods are available for tolerance enforcement: a gas 

chromatography method with nitrogen-phosphorus detection (GC/NPD), RAM 243/04, for the 

analysis of crop commodities for residues of azoxystrobin and its Z-isomer; and a GC/NPD 

method, RAM 255/01, for analysis of livestock commodities for residues of azoxystrobin. 

For analysis of samples from the potato postharvest field trials associated with the current 

petition, a high performance liquid chromatography method with tandem mass spectrometric

detection (LC/MS/MS), Method 305/03, was used as the data-collection method. RAM 305/03 

was adequately validated at fortification levels ranging from 0.01-10 ppm on potato tubers, 

potato flakes, and potato chips. 

There is an existing use for azoxystrobin on potatoes and corm vegetables subgroup 1C with an 

established tolerance of 0.03 ppm. Acceptable field trial studies have been submitted to support 

the requested tolerance increase of the established tolerance on tuberous and corm vegetables 

subgroup 1C from 0.03 ppm to 6.0 ppm; the studies are supported by adequate existing storage 

stability data. The Organization for Economic Cooperation and Development (OECD) statistical 
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

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calculation procedures were used to determine appropriate tolerance levels. Based on the 

available data, the proposed tolerance for vegetable, tuberous and corm, subgroup 1C must be 

revised to reflect the appropriate tolerance level estimated using the OECD statistical calculation 

procedures. HED recommends a tolerance of 8.0 ppm for vegetable, tuberous and corm, 

subgroup 1C.

The submitted postharvest potato processing study is acceptable. Residues of azoxystrobin did 

not concentrate in potato cakes, potato chips, and potato peel following processing of the raw 

agricultural commodity (RAC) (pre-processed tubers) with quantifiable residues. No tolerances 

are required for these processed commodities. 

Adequate cattle and poultry feeding studies are available to support the proposed uses. No 

changes to the existing livestock commodity tolerances are needed. 

Adequate field rotational crop data are available to support the existing rotational crop 

restrictions on the product labels: a 12-month plantback interval has been established for 

buckwheat, millet, oats, and rye; and a 36-day plantback interval has been established for the

leafy vegetables (except Brassica) group, the Brassica leafy greens subgroup, the root vegetables 

subgroup, the tuberous and corm vegetables subgroup, and the leaves of root and tuber 

vegetables group.

There are Canadian and Codex MRLs for residues of azoxystrobin and its (Z)-isomer for most of 

the requested crops. The Codex MRLs (JMPR Report 2008) are based on US field trials, except 

for subgroup 8-10A and 8-10B which were conducted in Europe. Even though the Codex MRLs 

are based on US field trials, there is a slight difference between MRLs of Codex/US due in part

to the difference in the residue definition. The US residue definition includes both the 

predominant E isomer and the minor Z isomer. The Codex residue definition includes only the E 

isomer. The difference in Codex and US MRL estimates, based on the same data set, is based on 

the JMPR rounding procedures and the tendency to increase the estimate for small data sets.

The US and Codex MRLs are in harmony for subgroup 13-07A, strawberries, and sunflower 

seeds. The US and Codex MRLs are not in harmony for subgroup 13-07G; dragon-fruit 

(mango); onion, bulb dry and green; vegetable subgroup 8-10A; tuberous and corm vegetables 

subgroup 1C and wasabi (herbs, fresh and dry).

HED recommends increasing the US tolerances for bushberry, subgroup 13-07B, cottonseed, 

citrus fruit, 10-10, fruit vine climbing 13-07F [grape], and pepper/eggplant 8-10B to harmonize 

with Codex.

The US and Canadian MRLs are in harmony on all proposed crops, except subgroup 13-07F, 13-

07G, and cotton seed. There are no Canadian tolerances on cottonseed. Canadian tolerances 

were not established as subgroups for 13-07F and 13-07G and were established on grapes (3 

ppm) and lowbush blueberries and lingonberries (subgroup 13-07B) at 3 ppm; US tolerances 

were established at 1 ppm for 13-07F and at 10 ppm for 13-07G. The current post-harvest use of 

the tuberous and corm vegetables subgroup 1C, recommends increasing the US tolerance for 

vegetable tuberous and corm, subgroup 1C to 8 ppm, which is in agreement with the proposed

Canadian MRL. 
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

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Analytical reference standards for azoxystrobin and its Z-isomer are currently available at the 

EPA National Pesticide Standards Repository.

Regulatory Recommendations and Residue Chemistry Deficiencies

Pending submission of a revised Sections B and F, there are no residue chemistry issues that will 

preclude establishment of permanent tolerances for azoxystrobin in/on the following crops or 

crop groups/subgroups:

Onion, bulb, subgroup 3-07A .......................................1.0 ppm

Onion, green, subgroup 3-07B......................................7.5 ppm

Tomato subgroup 8-10A...............................................0.2 ppm

Pepper/eggplant subgroup 8-10B..................................3.0 ppm

Fruit, citrus, group 10-10 ............................................15.0 ppm

Caneberry subgroup 13-07A.........................................5.0 ppm

Bushberry subgroup 13-07B .........................................5.0 ppm

Fruit, small vine climbing, except fuzzy kiwifruit, subgroup 

13-07F...........................................................................2.0 ppm

Berry, low growing, subgroup 13-07G, except cranberry..10.0

ppm

Rapeseed subgroup 20A................................................1.0 ppm

Sunflower subgroup 20B ..............................................0.5 ppm

Cottonseed subgroup 20C.............................................0.7 ppm

Wasabi, fresh..................................................................50 ppm

Wasabi, dry ..................................................................260 ppm

Dragon-fruit ..................................................................2.0 ppm

Vegetable, tuberous and corm, subgroup 1C ................8.0 ppm

Note to RM: In conjunction with establishment of the above tolerances, the existing 

tolerances for potato; onion, bulb; onion, green; vegetable, fruiting, group 8, except 

tomato; okra; tomato; fruit, citrus, group 10; caneberry subgroup 13A; bushberry 

subgroup 13B; grape; strawberry; juneberry; lingonberry; salal; cotton, undelinted seed; 

canola, seed; sunflower, seed; crambe, seed; flax, seed; rapeseed, seed; rapeseed, Indian; 

mustard, field, seed; mustard, Indian, seed; mustard, seed; and safflower, seed need to be 

removed from 40 CFR §180.507(a). 

Note to RM: The e-CFR includes the Z-isomer in the tolerance expression for livestock. The Zisomer should be removed from the tolerance expression for livestock.

A human health risk assessment is forthcoming.

Residue Chemistry Deficiencies

860.1200 Directions for Use

The proposed use directions for post-harvest potatoes should be revised to indicate postharvest use on tuberous and corm vegetables, subgroup 1C rather than on potatoes only.
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

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860.1550 Proposed Tolerances

A revised Section F must be submitted to reflect the recommended tolerance for 

vegetable, tuberous and corm, subgroup 1C at 8.0 ppm and the correct commodity 

definitions as shown in Table 9.

A revised Section F must be submitted to propose a tolerance for wasabi, dry at 260 ppm.

Background

The chemical structure and nomenclature of azoxystrobin and its Z-isomer, and the 

physicochemical properties of the technical grade of azoxystrobin are presented in Tables 1 and 

2, respectively.

Table 1. Azoxystrobin Nomenclature.

Compound

N N

O O

CN OCH3

O

H3CO

Common name Azoxystrobin

Company experimental name ICIA5504 (Zeneca), R215504 (Syngenta)

IUPAC name methyl (E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-

methoxyacrylate

CAS name methyl (αE)-2-[[6-(2-cyanophenoxy)-4-pyrimidinyl]oxy]-α-(methoxymethylene)-

benzeneacetate

CAS registry number 131860-33-8

End-use products (EP) Abound® Flowable Fungicide (EPA Reg. No. 100-1098);

Quilt® (EPA Reg. No. 100-1178), Graduate A+TM (EPA Reg. No. 100-1308), 

Quadris TopTM (EPA Reg. No. 100-1313), and Quilt XcelTM (EPA Reg. No. 100-

1324)

Regulated metabolite, Zisomer

N N

O O

CN

O OCH3

H3CO

Common name Azoxystrobin, Z-isomer

Chemical name methyl (Z)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-

methoxyacrylate
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

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Table 2. Physicochemical Properties of Technical Grade Azoxystrobin.

Parameter Value Reference

Melting point/range 114-116oC DP#s 218318 and 218448, 

3/19/96, J. Garbus pH 6.4

Density 1.25 g/cm3

Water solubility (20°C) pH 5.2 6.7 mg/L

pH 7.0 6.7 mg/L

pH 9.2 5.9 mg/L

Solvent solubility (20°C) Hexane 0.057 mg/L

Octanol 1.4 mg/L

Methanol 20 mg/L

Toluene 55 mg/L

Acetone 86 mg/L

Ethyl Acetate 130 mg/L

Acetonitrile 340 mg/L

Dichloromethane 400 mg/L

Vapor pressure (20°C) 1.1x10-13 kPa (8.2x10-13 mm Hg)

Dissociation constant, pKa Not dissociable

Octanol/water partition coefficient, 

Log(KOW)

log POW = 2.5

UV/visible absorption spectrum Not available

860.1200 Directions for Use

In Section B of the petition, IR-4 submitted amended labels for Abound® Flowable Fungicide 

(EPA Reg. No. 100-1098), to add new uses on potatoes (post-harvest), dragon fruit, wasabi, and 

crop group expansions. The petitioner has also requested amendment of the labels for Quilt® 

(EPA Reg. No. 100-1178), Graduate A+TM (EPA Reg. No. 100-1308), Quadris TopTM (EPA Reg. 

No. 100-1313), and Quilt XcelTM (EPA Reg. No. 100-1324) to reflect the revision/expansion of 

the crop groups. 

Table 3. Summary of Directions for Use of Azoxystrobin.

Applic. 

Timing, Type, 

and Equip.

Formulation

[EPA Reg. 

No.]

App. Rate 

(lb ai/A)

Max. 

No. 

App. /

Season

Max. 

Seasonal 

App. 

Rate

(lb ai/A)

PHI

(days)

Use Directions and 

Limitations

Potatoes (Post Harvest)

In-line 

aqueous spray 

application

2.08 lb 

ai/gal SC

[100-1098]

0.6 fl. 

oz./ton of 

tubers

0.0098 lb 

ai/2000

pound 

potatoes

1 N/A N/A Ensure proper coverage of 

the tubers. Tubers should be 

tumbling as they are treated.

Mix the fungicide solution in 

an appropriate amount of 

water for the crop being 

treated.

Use a T-jet, CDA, or similar 

application system.

Must be used in tank mixture 

with difenoconazole and 
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

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Table 3. Summary of Directions for Use of Azoxystrobin.

Applic. 

Timing, Type, 

and Equip.

Formulation

[EPA Reg. 

No.]

App. Rate 

(lb ai/A)

Max. 

No. 

App. /

Season

Max. 

Seasonal 

App. 

Rate

(lb ai/A)

PHI

(days)

Use Directions and 

Limitations

fludioxonil.

Do not make more than one 

postharvest application to 

tubers.

Ensure the Abound solution 

remains in suspension by 

using agitation. 

Herbs & Spices (except black pepper) Crop Group 19 (Existing), Wasabi (proposed)

Begin making 

applications at 

the onset of 

disease 

development

by ground.

For WasabiApply by 

ground or 

through 

irrigation 

system 

(chemigation)

Abound ® 

Fungicide 

[100-1098]

0.10-0.25 N/S 1.5 0 Applications should continue 

throughout the season on 7-

day intervals following the 

resistance management 

guidelines. Adjuvant may be 

added at specified rates. Use 

a minimum of 30 gallons of 

water per acre. 

Acerola, Atemoya, Avocado, Biriba, Canistel, Cherimoya, Custard apple, Dragon Fruit (proposed); Feijoa, 

Guava, Ilama, Jaboticaba, Jackfruit, Longan, Loquat, Lychee, Mango, Papaya, Passionfruit, Pawpaw, 

Persimmon, Pulasan, Rambutan, Sapodilla, Sapote black, Sapote, mamey, Sapote white, Soursop, Star apple, 

Starfruit, Sugar apple, Spanish lime, and Tamarind (Existing)

Apply by 

ground, air, or 

chemigation 

prior to 

disease 

development

Abound ® 

Fungicide 

[100-1098]

0.10-0.25 N/S 1.5 0 Applications should continue 

throughout the season on 7-

10-day interval following the 

resistance management 

guidelines. Adjuvant may 

be added at specified rates. 

Resistance Management: The label for Abound® (EPA Reg. No. 100-1098) specifies that the 

product should be integrated into an overall disease and pest management strategy and that for 

resistance management, no more than two foliar applications of Abound® Flowable Fungicide 

(one application for bulb vegetables, peppers and other fruiting vegetables) or other Group 11 

fungicides should be made before alternating with a fungicide having a different mode of action 

(not in Group 11). 

The following plantback intervals (PBIs) have been established: 12 months for buckwheat, 

millet, oats, and rye; 36 days for leafy vegetables (except Brassica) group, Brassica leafy greens 

subgroup, root vegetables subgroup, tuberous and corm vegetable subgroup, and leaves of root 

and tuber vegetables group; and 0 days for all other crops. 
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

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

the proposed uses. The proposed supplemental label for dragon-fruit and wasabi is adequate. 

The proposed use directions for post-harvest potatoes should be revised to indicate post-harvest 

use on tuberous and corm vegetables, subgroup 1C rather than on potatoes only.

860.1300 Nature of the Residue - Plants

PP#5F4541; DP#s 218318 and 218448, 3/19/96, J. Garbus 

PP#6F4762; DP#s 230634, 230635, 230636, and 230637; 4/25/97; L. Kutney 

HED Metabolism Assessment Review Committee Decision Memo; DP# 251683, 12/30/98, W. Wassell

Adequate metabolism studies on grapes, peanuts, and wheat were submitted in conjunction with 

earlier azoxystrobin petitions, PP#s 5F4541 and 6F4762. Azoxystrobin undergoes 

photochemical isomerization to produce the Z-isomer and is extensively metabolized in plants. 

The parent compound undergoes cleavage of the ether linkages between the phenylacrylate and 

pyrimidinyl rings and the cyanophenyl and pyrimidinyl rings, with subsequent oxidation, 

hydrolysis, and/or reduction of the primary metabolites to form numerous secondary metabolites. 

Azoxystrobin is systemic. HED has determined that the residues of concern in/on plants for 

tolerance expression and risk assessment purposes are azoxystrobin and its Z-isomer.

860.1300 Nature of the Residue - Livestock

PP#5F4541; DP#s 218318 and 218448, 3/19/96, J. Garbus 

PP#6F4762; DP#s 230634, 230635, 230636, and 230637; 4/25/97; L. Kutney 

HED Metabolism Assessment Review Committee Decision Memo; DP# 251683, 12/30/98, W. Wassell

The nature of the residue in livestock is adequately understood based on acceptable metabolism 

studies conducted on goats and laying hens. HED has determined that the residue of concern in 

livestock is parent azoxystrobin only. 

860.1340 Residue Analytical Methods

Enforcement methods

PP#s 5F4541 & 6F4762; DP# 235342, 5/30/97, C. Stafford

PP#7F4864; DP#s 249657 and 249668, 1/25/99, D. Dotson 

PP#s 6F7106 & 7F7198; DP#s 334571 & 340016, 3/12/08, W. Cutchin

Crop commodities: A GC/NPD method, RAM 243/04, is available for the enforcement of 

tolerances for residues of azoxystrobin and its Z-isomer in crop commodities. The method has 

undergone method validation by Analytical Chemistry Branch/Biological and Economic Analysis 

Division (ACB/BEAD). The method was revised to incorporate comments made by BEAD, and 

the revised method (designated RAM 243, dated 5/15/98) has been submitted to FDA for 

inclusion in Pesticide Analytical Manual (PAM), Volume II. The limit of quantitation (LOQ) is 

0.01 ppm for each analyte in crop commodities. 

Livestock commodities: A GC/NPD method, RAM 255/01, is available for the enforcement of 

tolerances for residues of azoxystrobin in livestock commodities. The method has been validated 
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 11 of 37

by ACB/BEAD for the analysis of milk and liver. The method LOQ is 0.0025 ppm and 0.01 

ppm for each analyte in milk and tissues, respectively.

Data-collection method

Samples from the potato postharvest trial submitted with the current petition were analyzed for 

residues of azoxystrobin and its Z-isomer using LC/MS/MS Method RAM 305/03. This method 

has been reviewed previously by HED, under PP#s 6F7106 and 7F7198. 

Briefly, samples were extracted with acetonitrile (ACN):water (90:10, v:v). After centrifugation, 

an aliquot of the extract was cleaned up on a C18 solid phase extraction column and analyzed 

using LC-MS/MS detection. The LC/MS/MS method uses a single ion transition, m/z 

404.1→372.1, to quantitate azoxystrobin and R230310 residues in/on plant commodities. For 

confirmation, the LC/MS/MS method may be used to monitor additional ion transitions, m/z 

404.1→344.0 and 404.1→329.0.

For potato postharvest samples, the LOQ, determined as the lower limit of method validation 

(LLMV), was 0.01 ppm for each analyte; the limit of detection (LOD) was not reported. 

The method was verified prior to and in conjunction with sample analyses and is considered 

adequate based on acceptable method validation and concurrent recovery data. Samples of 

potato were fortified with azoxystrobin and its Z-isomer each at 0.01-10 ppm. The fortification 

levels used in method validation and concurrent method recovery were adequate to bracket 

expected residue levels.

Conclusions: There are adequate residue analytical methods for tolerance enforcement in crop 

and livestock commodities. The LC/MS/MS method used for determination of azoxystrobin and 

its Z-isomer in potato, RAM 305/03, was adequate for data collection purposes based on 

acceptable concurrent method recoveries.

860.1360 Multiresidue Methods

PP#5F4541; DP#s 218318 and 218448, 3/19/96, J. Garbus 

Data have previously been submitted pertaining to the multiresidue methods testing of 

azoxystrobin in conjunction with the grape petition (PP#5F4541). The data indicate that 

azoxystrobin could not be recovered through application of the multiresidue protocols. These 

data have been forwarded to FDA for inclusion in PAM I.

860.1380 Storage Stability

PP#7F4864; DP#s 248887 and 249671, 10/14/98, D. Dotson, et al.

PP#7F4864; DP#s 249657 and 249668, 1/25/99, D. Dotson

Adequate storage stability data are available indicating that azoxystrobin and its Z-isomer are 

reasonably stable under frozen conditions in/on fortified samples of diverse crops. In previous 

studies, residues were determined to be stable for two years in/on apple, banana, carrot, 

cucumber, grape, leaf lettuce, rape seed, peach, winter wheat straw, wheat forage, and wine. 
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 12 of 37

Over the two-year period, residues of both azoxystrobin and its Z-isomer decreased by up to 20% 

in winter wheat grain and by up to 27% (azoxystrobin only) in tomato, peanut, and pecan, but all 

recoveries were >70%; residues in these crops were stable (without decrease) for up to 6-8 

months of storage.

Previous studies conducted on processed commodities demonstrated that fortified residues of 

azoxystrobin and its Z-isomer were generally stable under frozen conditions in peanut oil and 

meal, tomato juice and paste, and wheat bran for up to one year, and in soybean meal, corn grits, 

and orange oil, juice and pulp for at least two years.

Samples of postharvest potatoes from the submitted field trial study were stored frozen from

harvest to analysis for up to 258 days (8.5 months). The available storage stability data on 

carrots may be translated to postharvest potatoes.

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

Matrix Analyte Storage 

Temperature (°C)

Actual Storage Duration1 Limit of Demonstrated Storage Stability

Potato

Azoxystrobin

<-10 10-258 days

(0.3-8.5 months)

Adequate storage stability data are 

available indicating that residues of 

azoxystrobin and R230310 are stable at 

<-15 C for at least two years in/on 

soybean meal, corn grits, carrot root, 

leaf lettuce, grain sorghum forage, 

orange oil, and orange juice.2

Additionally, data on file indicate 

residues of azoxystrobin and R230310 

are stable for up to 2 years in 

cucumbers, apples, grapes, peaches, 

peanuts, pecans, rapeseed, tomatoes, 

bananas, and wheat grain.3

R230310

1

Interval from sampling to analysis. Extracts were stored 0-3 days prior to analysis.

2 Refer to DER for MRID 45738101 (DP# 287062; PMRA # 956496).

3 Refer to DER for MRID 44452303; PMRA # 1191031.

Conclusions: There are adequate storage stability data from previous submissions to validate the 

storage conditions and durations of samples from the submitted postharvest potatoes. Residues 

of azoxystrobin and its Z-isomer were found to be relatively stable over a wide range of 

commodities under frozen storage conditions for up to 2 years. The potato residue data will not 

need to be corrected for loss of residue during frozen storage. 

860.1400 Water, Fish, and Irrigated Crops

There are no proposed uses relevant to this guideline topic.

860.1460 Food Handling

There are no proposed uses relevant to this guideline topic.
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

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860.1480 Meat, Milk, Poultry, and Eggs

PP#6F4762; DP#s 230634, 230635, 230636, and 230637; 4/25/97; L. Kutney 

PP#7F4864; DP#s 249657 and 249668, 1/25/99, D. Dotson 

Tolerances for residues of azoxystrobin are currently established [40 CFR §180.507(a)(2)] for the 

fat (0.03 ppm), meat (0.01 ppm), and meat byproducts (0.07 ppm) of cattle, goat, horse, and 

sheep. A tolerance of 0.01 ppm each has been established for hog fat, meat, and meat 

byproducts. A milk tolerance of 0.006 ppm is also established. No tolerances for eggs and 

poultry meat and meat byproducts have been established. 

Previously, the maximum theoretical dietary burdens (MTDBs) of azoxystrobin were estimated 

to be 51.3 ppm for beef, 40.4 for dairy cattle, 14.4 ppm for poultry, and 15.0 ppm for swine (DP# 

362963 & 363046, M. Negussie, 08/20/09). The livestock feedstuffs associated with this petition 

are potato culls and processed potato waste; in addition, there are established tolerances for 

numerous livestock feedstuffs. Using Table 1 Feedstuffs (June 2008) and constructing 

reasonably balanced livestock diets, the previously estimated livestock dietary burdens of 

azoxystrobin were revised to include the processed potato waste (dairy cattle only) and are 

presented in Table 5. The dietary burdens of azoxystrobin are estimated at 51.3 ppm (beef), 44.4 

ppm (dairy cattle), 14.4 ppm (poultry), and 15 ppm (swine). 

Table 5. Calculation of Dietary Burdens of Azoxystrobin Residues to Livestock.

Feedstuff Type1 % Dry 

Matter2 % Diet2

Recommended/

Established 

Tolerance (ppm)

Dietary Contribution 

(ppm)3

Beef Cattle

Alfalfa hay R 89 15 120 20.2

Aspirated grain fractions CC 85 5 420 24.7

Barley grain CC 88 35 3.0 1.19

Sorghum grain CC 86 40 11 5.12

Canola meal PC 88 5 1.0 0.057

TOTAL BURDEN -- -- 100 -- 51.3

Dairy Cattle

Alfalfa hay R 89 20 120 27.0

Corn, field, silage R 40 25 12 7.5

Sorghum grain CC 86 35 11 4.5

Processed potato waste CC 15 10 8 5.3

Canola meal PC 88 10 1.0 0.114

TOTAL BURDEN -- -- 100 -- 44.4

Poultry

Sorghum grain CC 86 75 11 8.25

Alfalfa meal PC 89 5 120 6.0

Cottonseed meal PC 88 20 0.6 0.12

TOTAL BURDEN -- -- 100 -- 14.4

Swine

Barley grain CC 88 5 3.0 0.15

Sorghum grain CC 86 80 11 8.8
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 14 of 37

Table 5. Calculation of Dietary Burdens of Azoxystrobin Residues to Livestock.

Feedstuff Type1 % Dry 

Matter2 % Diet2

Recommended/

Established 

Tolerance (ppm)

Dietary Contribution 

(ppm)3

Alfalfa meal PC 89 5 120 6.0

Soybean meal PC 92 10 0.5 0.05

TOTAL BURDEN -- -- 100 -- 15.0

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.

Comments

1) Alfalfa hay is chosen because it is the most widely used hay for cattle across the US.

2) Normally alfalfa hay will be given over alfalfa forage mainly because many production animals are in confined 

spaces and not grazing in pastures.

3) Canola and cottonseed meals are listed in diets, but could be replaced with soybean meal and not affect the 

proposed diets and total dietary burdens.

4) Rice grain could replace the barley grain for swine, but would not affect the total estimated dietary burden.

Adequate livestock feeding studies have been submitted previously for azoxystrobin. A dairy 

cattle feeding study was reviewed in conjunction with PP#6F4762 and a study with laying hens 

was reviewed in conjunction with PP#7F4864. In the cattle feeding study, cattle were dosed at 

levels of 5, 25, 75, and 250 ppm for 28-30 consecutive days. The dosing levels represent ~0.1x, 

0.5x, 1.5x, and 4.9x the dietary burden for beef cattle, ~0.1x, 0.6x, 1.7x, and 5.6x the dietary 

burden for dairy cattle, and ~0.3x, 1.7x, 5x, and 16.7x the dietary burden for swine. Milk and 

tissue samples were analyzed for residues of azoxystrobin using the enforcement method for 

livestock commodities, with LOQs of 0.001 ppm for milk and 0.01 ppm for tissues and cream. 

The results of the cattle feeding study are summarized in Table 6. 

In the poultry study, hens were dosed at levels of 60 ppm for 28 consecutive days; the dosing 

level represents 4.2x the dietary burden to poultry (the study included lower dose rates of 6.0 and 

18 ppm; however, these samples were not analyzed). Egg and tissue samples were analyzed for 

residues of azoxystrobin using the enforcement method for livestock commodities, with an LOQ 

of 0.01 ppm for each matrix. No quantifiable residues were found in any poultry commodity (see 

Table 6).

Table 6. Summary of Azoxystrobin Residues in Livestock Matrices Following the Oral 

Administration of Azoxystrobin over 28-30 Consecutive Days.

Dose Rate in 

Diet (mg/kg)

Azoxystrobin Residues (ppm)

Milk/Eggs Muscle Fat Kidney Liver

Dairy Cattle

5 <0.001-0.003 <0.01 <0.01 <0.01 <0.01

25 <0.001-0.006 <0.01 <0.01 <0.01 <0.01-0.01

75 <0.001-0.004 <0.01 <0.01-0.03 <0.01-0.01 0.01-0.05

250 0.002-0.009 <0.01 0.01-0.03 0.01-0.02 0.03-0.07

Laying Hens

60 <0.01 <0.01 <0.01 Not analyzed <0.01
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 15 of 37

Conclusions: The existing azoxystrobin tolerances for milk and the fat, meat, and meat 

byproducts of cattle, goat, hog, horse, and sheep are adequate; no revision to the existing 

tolerances is needed to support the proposed uses of azoxystrobin. 

The proposed uses of azoxystrobin addressed in this document do not alter the Agency’s previous

conclusion that there is no reasonable expectation of finite residues in poultry commodities 

[Category 3 of §180.6(a)]. No tolerances are needed for poultry tissues or eggs. 

860.1500 Crop Field Trials

Other than the postharvest potato field trial data (MRID 48437101), no new residue field trial 

data were submitted to support the proposed tolerances. The changes are a result of revised crop 

groups and are conversions from existing groups/subgroups or representative commodities. The 

proposed tolerances for the dragon fruit and wasabi are extrapolated from existing azoxystrobin 

tolerances on mango (2.0 ppm) and herb subgroup 19A, fresh (50 ppm), respectively. 

Tuberous and corm vegetables subgroup 1C (Potato-Post Harvest)

DER Reference: 48437101.der1.doc

Syngenta submitted residue data for azoxystrobin on potatoes following postharvest treatment.

Five postharvest trials were conducted in the United States and Canada in 2009-2010 in the 

North American Free Trade Agreement (NAFTA) Growing Zones 1 (ME; 1 trial), 5A (WI; 1 

trial), 5 (ON; 1 trial), and 11 (WA and ID; 2 trials). 

Potatoes were grown on-site by the trial personnel in the US trials and were obtained from a 

commercial grower in the Canadian trial. Samples of mature potato tubers were harvested from 

all trials, placed in on-site storage for ~1-4 months, and then treated with a spray mixture 

containing a 3.00 lb ai/gal (360 g a.i./L) difenoconazole flowable suspension (FS) formulation, a 

2.09 lb ai/gal (250 g a.i./L) azoxystrobin soluble concentrate (SC) formulation, and a 1.92 lb

ai/gal (230 g a.i./L) fludioxonil SC formulation. 

In all trials, the test mixture was applied as a postharvest treatment spray directed to tubers 

falling from a conveyor belt or moving along a roller table (TRT 02). At the ID trial, three 

additional treatment scenarios were included: surface spray directed to tubers on a tarp (TRT 03); 

spray directed to tubers in a spray chamber (TRT 04); and spray directed to tubers on a brush 

table (TRT 05). For each treatment, azoxystrobin was applied at a rate of 0.0089-0.0099 lb 

ai/2000 lb potatoes (4.0309-4.5105 g ai/2000 lb potatoes, (0.44-0.50 g a.i./100 kg potatoes) using 

water as the carrier; the delivery rate was 0.22-0.54 gal/2000 lb potatoes (0.09-0.23 L/100 kg 

potatoes). 

Samples of potatoes from each trial site were collected after the test substance had dried on the 

day of application [0 days after application (DAA)]. At three sites (WA, ON, and ID), additional 

treated samples were collected and placed in storage for 13-14, 30-32, 59-61, and/or 231 days after 

application to generate residue decline data. 

Potato samples were analyzed for residues of azoxystrobin and its metabolite R230310 using 

LC/MS/MS; modified Syngenta Analytical Method RAM 305/03 (MRID# 47096401; PMRA # 
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 16 of 37

2044022). This method has been reviewed previously and deemed acceptable for data gathering. 

The limit of quantitation (LOQ; determined as the lowest limit of method validation, LLMV) was

0.01 ppm for both analytes. The method was verified prior to and in conjunction with sample 

analyses and is considered adequate based on acceptable method validation and concurrent 

recovery data. The fortification levels used in method validation and concurrent method 

recovery were adequate to bracket expected residue levels.

Potato samples were stored at <-10 °C prior to analysis for a maximum of 258 days (8.5 months). 

All samples were analyzed within 0 to 3 days of extraction. Adequate storage stability data are 

available indicating that residues of azoxystrobin and R230310 are stable at <-15 C for at least 

24 months in/on soybean meal, corn grits, carrot root, leaf lettuce, grain sorghum forage, orange 

oil, and orange juice (MRID 45738101; PMRA # 956496). Additionally, data on file indicate 

residues of azoxystrobin and R230310 are stable for up to 2 years in cucumbers, apples, grapes, 

peaches, peanuts, pecans, rapeseed, tomatoes, bananas, and wheat grain (MRID 44452303; 

PMRA # 1191031). These data may be translated to potatoes to validate the storage durations 

and conditions of azoxystrobin and R230310 for the potato field trial samples (OECD Guidelines 

for the Testing of Chemicals, Test No. 506, Adopted 16 October, 2007). 

Residues of azoxystrobin were 0.992-4.15 ppm (per trial average residues were 0.994-3.79 ppm) 

in/on potatoes collected 0 DAA following one postharvest spray treatment application of

azoxystrobin formulated as a 2.09 lb ai/gal (250 g a.i./L) SC at a total seasonal rate of 0.0089-

0.0099 lb ai/2000 lb potatoes (0.44-0.50 g a.i./100 kg potatoes). Residues of R230310 were all 

<LOQ (0.01 ppm). All application methods (directed spray to tubers on a conveyor belt, roller 

table, stationary surface, spray chamber, or brush table) resulted in similar residue levels.

In the ON decline trial, residues of azoxystrobin remained constant; residues of azoxystrobin 

from the WA and ID trials generally decreased with increasing DAA. Residues of R230310 were 

<LOQ at each sampling interval; therefore, residue decline could not be assessed for the 

metabolite.

Table 7. Summary of Residue Data from Potato Crop Field Trials with Azoxystrobin.

Commodity Analyte Total App. 

Rate

DAA Residue Levels (ppm)1

g a.i./

2000 lb

lb a.i./

2000 lb

[g 

a.i./100 

kg

n Sample 

Min.

Sample 

Max.

LAFT3 HAFT3 Median Mean Std. Dev.

4

TRT 02 (Conveyor Belt or Roller Table)

Potato 

tubers

Azoxystrobin 4.0473-

4.5105

0.0089-

0.0099

[0.45-

0.50]

0 10 0.992 4.15 0.994 3.79 2.22 2.40 1.20

R230310 10 <0.01 <0.01 0.01 0.01 0.01 0.01 N/A

Total Residues 10 <1.002 <4.16 1.004 3.80 2.23 2.41 1.20

TRT 03 (Surface)/Stationary

Potato 

tubers

Azoxystrobin 4.0997 0.0090

[0.45]

0 2 1.05 1.22 1.14 1.14 N/A N/A N/A

R230310 2 <0.01 <0.01 0.01 0.01 N/A N/A N/A

Total Residues 2 <1.06 <1.23 1.15 1.15 N/A N/A N/A

TRT 04 (Spray Chamber)

Potato 

tubers

Azoxystrobin 4.0309 0.0089

[0.44]

0 2 3.50 3.57 3.54 3.54 N/A N/A N/A

R230310 2 <0.01 <0.01 0.01 0.01 N/A N/A N/A
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 17 of 37

Table 7. Summary of Residue Data from Potato Crop Field Trials with Azoxystrobin.

Commodity Analyte Total App. 

Rate

DAA Residue Levels (ppm)1

g a.i./

2000 lb

lb a.i./

2000 lb

[g 

a.i./100 

kg

n Sample 

Min.

Sample 

Max.

LAFT3 HAFT3 Median Mean Std. Dev.

4

Total Residues 2 <3.51 <3.58 3.55 3.55 N/A N/A N/A

TRT 05 (Brush Table)

Potato 

tubers

Azoxystrobin 4.0850 0.0090

[0.45]

0 2 2.23 2.31 2.27 2.27 N/A N/A N/A

R230310 2 <0.01 <0.01 0.01 0.01 N/A N/A N/A

Total Residues 2 <2.24 <2.32 2.28 2.28 N/A N/A N/A

Combined Treatments

Potato 

tubers

Azoxystrobin 4.0309-

4.5105

0.0089-

0.0099

[0.44-

0.50]

0 1610.992 4.15 -- -- 2.25 2.37 1.12

8

2

-- -- 0.994 3.79 2.25 2.37 1.15

R230310 161<0.01 <0.01 -- -- 0.01 0.01 N/A

8

2

-- -- 0.01 0.01 0.01 0.01 N/A

Total Residues 161<1.002 <4.16 -- -- 2.26 2.38 1.12

8

2

-- -- 1.004 3.80 2.25 2.37 1.15

1

n = no. of samples. For calculation of median, mean, and standard deviation, the LOQ (0.01 ppm) was used for any results 

reported as <LOQ in Table C.3.

2

n = no. of field trials; statistical calculations are based on per-trial average values. 

3 LAFT = lowest-average-field-trial; HAFT = highest-average-field-trial.

4 N/A = Not applicable.

Conclusions: The supervised residue trials on potato are considered scientifically acceptable. 

Based on the study results, residues of azoxystrobin may be up to 4.15 ppm (per trial average 

maximum of 3.79 ppm) in/on potato collected at 0 DAA following postharvest spray application

of azoxystrobin, formulated as a 2.09 lb ai/gal SC, at a total rate of 0.0089-0.0099 lb ai/2000 lb 

potatoes (4.0309-4.5105 g a.i./2000 lb potatoes); maximum residues of metabolite R230310 in 

potatoes were <0.01 ppm. Samples were analyzed for azoxystrobin and the metabolite R230310

using acceptable methods. The study is supported by adequate storage stability data for 

azoxystrobin and R230310. 

The average residue values for the potato postharvest use were used to calculate the tolerance. 

Using the OECD statistical procedures, the recommended tolerance is 8 ppm. The recommended 

tolerance is higher than the proposed tolerance (6 ppm). Thus, a revised Section F is required to 

reflect this determination.

Note to PM: The existing separate tolerance on potato should be removed and the established 

vegetable, tuberous and corm, subgroup 1C need to be revised. 

Crop Field Trial Data in Support of Crop Group/Subgroup Expansions.

The adequacy of the available data to support the crop group/subgroup expansions is discussed 

below for each crop and/or crop group/subgroup.
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 18 of 37

Caneberry subgroup 13-07A

Residue Chemistry Memo DP# 279210, N. Dodd, 06/19/02

DER Reference: 45522301

Tolerances have been established for the combined residues of azoxystrobin and its Z-isomer 

in/on caneberry subgroup 13A at 5.0 ppm. Tolerances were established based on the results from 

three crop field trials conducted in OR (2 trials) and WA (1 trial) in/on raspberry or blackberry 

and cranberry. Azoxystrobin (80% WDG) was applied to raspberry or blackberry plants as 6 or 7 

foliar directed spray applications at 0.24-0.26 lb ai/A/application, for a total of 1.5-1.8 lb 

ai/A/season (1-1.2x the maximum proposed rate). Caneberry fruits were harvested on the day of 

the last application (0-day PHI). The combined residues of azoxystrobin and R230310 were 

<0.69-3.69 ppm in/on samples of caneberry (4 raspberry and 2 blackberry) fruit. 

The required number of field trials for blackberry or raspberry as representative crops to establish 

a tolerance for the caneberry subgroup 13-07A is 3 trials for any one blackberry or raspberry 

(ChemSAC 7/8/2009).

Bushberry subgroup 13-07B

Residue Chemistry Memo DP# 274312, G. J. Herndon, 07/10/2001

DER Reference: 45253901

Tolerances have been established for the combined residues of azoxystrobin and its Z-isomer 

in/on bushberry subgroup 13B at 3.0 ppm. The tolerances were established based on the results 

from the supervised crop field trials in blueberries. Seven trials conducted in Regions 1 (ME; 1 

trial), 2 (NC; 2 trials), 5 (MI; 3 trials), and 12 (OR; 1 trial) were submitted. The results have 

shown that the maximum residues in blueberry treated six times with Quadris 80WG at 0.25 lbs 

ai/A/application (equivalent to 1X the proposed rate) and collected 0 days following the last 

application were 1.63 ppm. 

The required number of field trials for highbush blueberry as the representative crop to establish 

a tolerance for the bushberry subgroup 13-07B is 8 trials for highbush blueberry (ChemSAC 

7/8/2009). 

Small fruit vine climbing, except fuzzy kiwifruit subgroup 13-07F

Residue Chemistry Memo DP# 218318 & 218448, DP#226232, J. Garbus, 3/19/96

DER References: 43678209, 43678210 and 44002200

Tolerances have been established for the combined residues of azoxystrobin and its Z-isomer 

in/on grapes at 1.0 ppm based on trials conducted in Europe and the US. Seven of the trials were 

conducted in the US at 6 sites; Regions 1 (NY; 1trial); 11 (WA; 1 trial); 10 (CA; 3 trials) and 1 

trial each in AK and MI, areas not generally associated with viticulture. In addition, nine field 

trials were conducted in the US in Region 1 (NY; 1 trial), Region 10 (CA; 6 trials), and Region 

11 (OR and WA; 2 trials) to satisfy the requirement for geographic representation. The results 

of 10 other trials conducted in Europe are also available. The results from the US trials have 

shown that the maximum residues in grapes, harvested 12 to 19 days following the last 

application of a wettable granular (WG) formulation, and treated six times at 0.25 lbs 

ai/A/application, equivalent for a total of 1.5 lbs ai/A/season (1X the proposed rate), were 0.81

ppm. 
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 19 of 37

The required number of field trials for grapes as the representative crop to establish a tolerance 

for the fruit, small vine climbing, except fuzzy kiwifruit, subgroup 13-07F is 12 trials for grapes 

(ChemSAC 7/8/2009). 

Note to PM: The existing separate tolerance on grape should be removed when the subgroup 

tolerance is established.

Berry, low growing, subgroup 13-07G, except cranberry. 

Residue Chemistry Memo DP# 274312, G. J. Herndon, 07/10/2001

DER Reference: 45205604

Tolerances have been established for the combined residues of azoxystrobin and its Z-isomer 

in/on strawberry at 10.0 ppm. The tolerances were established based on the results from the 

supervised crop field trials on strawberries. Seven trials conducted in Regions 3 (FL; 2 trials), 5 

(WI; 1 trial), 10 (CA; 3 trials), and 12 (OR; 1 trial) were submitted. The results from the crop 

field trials on strawberry have shown that the maximum residues in strawberry treated six times 

with Quadris 80WG at 0.25 lbs ai/A/application (equivalent to 1X the proposed rate) and 

collected 0 days following the last application were 5.11 ppm. 

The required number of field trials for strawberry as the representative crop for the berry, low 

growing, subgroup 13-07G, except cranberry is 8 trials for strawberry (ChemSAC 7/8/2009). 

Note to PM: The existing separate tolerance on strawberry should be removed when the 

subgroup tolerance is established.

Citrus Fruits

Residue Chemistry Memo DP# 260134, M. J. Nelson, 09/06/2000

Residue Chemistry Memo DP# 312949, W. Cutchin, 01/23/2006

DER References: 44915217, 44915224, and 44915225

DER Reference: 46509101CFT 

Tolerances have been established for the combined residues of azoxystrobin and its Z-isomer 

in/on fruit, citrus, group 10 at 10 ppm. Twenty-three field trials were conducted on the 

representative crops (sweet orange, lemon, and grapefruit). Six trials were conducted on 

grapefruit in Regions 3 (FL; 3 trials), 6 (TX; 1 trial), and 10 (CA; 2 trials); 5 trials were 

conducted on lemons in Regions 3 (FL; 1 trial) and 10 (CA, AZ; 4 trials); and 12 trials were 

conducted on oranges in Regions 3 (FL; 8 trials), 6 (TX; 1 trial), and 10 (CA; 3 trials). Residues 

of azoxystrobin were 0.16-0.41 ppm in/on grapefruit, 0.27-0.74 ppm in/on lemons, and 0.09-0.53 

Fppm in/on oranges harvested 0 days following the last of six applications, with 6- to 8-day 

retreatment intervals, of the 80% WDG formulation at 0.25 lb ai/A/application, for a total 

application rate of 1.5 lb ai/A/season (1x the maximum proposed seasonal application rate). 

In addition, citrus field trials treated with both preharvest and postharvest applications were 

submitted. The submitted data were obtained from trials conducted in Regions 3 (FL; 1 trial), 6 

(TX; 1 trial), and 10 (CA; 4 trials). For pre-harvest, treated plot received two foliar applications 

at ~ 0.25 lb a.i./A/A and harvested at 0-day PHI. 

All post-harvest test solutions contained Azoxystrobin 80WG and were applied at 1.0 lb a.i./100 

gal water (dip) and 1.0 lb a.i./250,000 lb fruits (packing-line spray). Citrus field trials were 
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 20 of 37

conducted using simulated postharvest applications (using six different postharvest methods) 

following normal pre-harvest use. The highest azoxystrobin residues were detected in grapefruit, 

orange, and lemon samples that received pre-harvest as well as postharvest dip treatments 

ranging from 1.185 to 5.427 ppm, 1.213 to 3.994 ppm, and 1.466 to 9.182 ppm, respectively. 

Based on these field trial data, the tolerance was established on the citrus fruit group 10 at 10.0 

ppm. 

Onion, bulb, subgroup 3-07A and Onion, green, subgroup 3-07B

Residue Chemistry Memo DP# 260134, M. J. Nelson, 09/06/2000

DER References: 44915210 and 44915226

Tolerances have been established for the combined residues of azoxystrobin and its Z-isomer 

in/on onion, bulb and onion, green at 1.0 and 7.5 ppm, respectively. The tolerances were 

established based on the results from crop field trials on bulb onions and green onions. Eight 

bulb onion field trials were conducted in Regions 1 (NY; 1 trial), 5 (IL; 1 trial), 6 (TX; 1 trial), 8 

(CO; 1 trial), 10 (CA; 2 trials), 11 (WA; 1 trial), and 12 (OR; 1 trial). Three green onion trials 

were conducted in Regions 6 (TX; 1 trial) and 10 (CA and AZ; 1 trial each). 

The results have shown that the maximum residues in bulb onions and green onions treated six 

times with Quadris 80 WDG at 0.25 lbs ai/A/application (equivalent to 1X the proposed rate of 

1.5 lb ai/A/season) and collected 0 days following the last application were 0.67 and 6.91 ppm, 

respectively. 

Rapeseed subgroup 20A

Residue Chemistry Memo DP# 312949, W. Cutchin, 01/23/2006

DER Reference: 46046604CFT

Residue Chemistry Memo PP#s 7F4864 & 8F4995, DP Barcode: D249657 & D249668, D. Dotson, 1/25/99

DER References: 44613502 and 44595108

Canola is the representative crop for the rapeseed subgroup 20A. Tolerances have been 

established for the combined residues of azoxystrobin and its Z-isomer in/on canola, seed at 1.0 

ppm and rapeseed, seed at 0.5 ppm. Eleven crop field trials s for azoxystrobin in/on canola were 

submitted. Nine of these trials were conducted in Canada and two were conducted in the U.S., in 

Regions 7 (ND) and 11 (WA). Azoxystrobin was applied (WDG 80%) as a foliar broadcast 

spray at the target rate of 0.15 lb ai/A-0.34 lb ai/A/application. The label specifies a use rate of 

0.1-0.25 lb ai/acre/application with a maximum of three applications and a maximum rate of 0.45 

lb ai/acre/season. The highest application rate was three applications of 0.17, 0.34, and 0.34 lb 

ai/acre which result in a total application of 0.85 lb ai/acre/season. This rate is 1.9x the 

maximum rate specified on the label (0.45 lb ai/acre/season). The highest field trial value for the 

combined residues of azoxystrobin and R230310 was 0.80, which was obtained from application 

of azoxystrobin at a rate of 1.9x the maximum rate specified on the label. 

In addition, there is existing field trial data from nine trials conducted in Canada encompassing 

Regions V (MB), VII (SK), and XIV (AB [3], SK [2], MB [2]) in or on canola treated with 

Quadris 2.08 SC. This formulation was applied three times as a foliar broadcast spray at the 

target rate of ~0.11 lb ai/A (0.123 kg ai/ha) for the first and third applications and at the target 

rate of ~0.23 lb ai/A (0.258 kg ai/ha) for the second application. The target seasonal application 

rate for the treated plots was 0.45 lb ai/A (0.504 kg ai/ha). The maximum residues found for 

azoxystrobin and R230310 were 0.23 ppm and 0.02 ppm, respectively. Based on these data, 
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 21 of 37

tolerances were established at 0.5 ppm in Indian rapeseed, Indian mustard seed, field mustard 

seed, black mustard seed, flax seed, sunflower seed, safflower seed, and crambe seed.

Tolerances on canola seed were established at 1.0 ppm using the highest use rate tested. The 1.0 

ppm tolerance level is adequate to cover the rapeseed subgroup 20A. 

Note to PM: The existing separate tolerances on canola, seed; crambe, seed; flax, seed; rapeseed, 

seed; rapeseed, Indian; mustard, field seed; and mustard, Indian, seed should be removed when 

the subgroup tolerance is established.

Sunflower subgroup 20B

Residue Chemistry Memo DP# 312949, W. Cutchin, 01/23/2006

DER References: 46046601CFT and 46046602

Tolerances have been established for the combined residues of azoxystrobin and its Z-isomer 

in/on sunflower seeds at 0.5 ppm. The tolerances were established based on submitted data from 

six trials in the USA encompassing Regions 5 (MN and ND; 2 trials), 7 (NE, ND, and SD; 3 

trials), 8 (TX; 1 trial), and four trials in Canada encompassing Regions 5 (MB; 1 trial), 7 (SK; 1 

trial), 14 (AB and MB; 2 trials). In the USA, azoxystrobin was applied as Quadris 80 WG, 

containing 81.4% azoxystrobin. In Canada, azoxystrobin was applied as Quadris 2.08 SC, which 

is a soluble concentrate containing 22.8% azoxystrobin. Both formulations were applied three 

times as a foliar broadcast spray at the target rate of ~0.11 lb ai/A/application for the first and 

third applications and at the target rate of ~0.23 lb ai/A/application for the second application. 

The target seasonal application rate for the treated plots was ~0.45 lb ai/A. The results from 

these trials have shown that the maximum residues in sunflower seeds collected 28-30 days

following the last application are 0.24 ppm and 0.01 ppm for azoxystrobin and R230310, 

respectively.

Note to PM: The existing separate tolerances on sunflower, seed and safflower, seed should be 

removed when the subgroup tolerance is established.

Cottonseed subgroup 20C

Cotton

Residue Chemistry Memo DP# 334571, W. Cutchin, 03/12/2008

DER Reference: 47096402

Tolerances have been established for the combined residues of azoxystrobin and its Z-isomer 

in/on cotton, undelinted seed at 0.6 ppm and in/on cotton, gin byproducts at 45 ppm. Twelve 

cotton field trials were conducted in the United States in Regions 2 (SC; 1 trial), 4 (AR, LA, MS; 

3 trials), 6 (TX; 1 trial), 8 (NM, OK, TX; 4 trials), and 10 (CA; 3 trials). The treated plot 

received one in-furrow application of a 2.08 lb/gal FlC formulation of azoxystrobin at planting of 

cotton at a target rate 0.15 lb ai/A/application, followed by three foliar broadcast applications of 

the 2.08 lb/gal FlC formulation at a rate of 0.14-0.16 lb ai/A/application. The in-furrow rate and 

foliar treatment rates are equivalent to 1-1.9x the proposed maximum seasonal rate. Cottonseed 

was harvested 45 days after last application (DALA), and samples from 6 trials (3 picker 

harvested; 3 stripper harvested) were ginned for cotton gin byproducts (trash). The results from 
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 22 of 37

the crop field trials on cotton have shown that maximum combined residues (azoxystrobin + 

R230310) were 0.62 ppm in/on cottonseed and 34.4 ppm in/on cotton gin byproducts. 

Note to PM: The existing separate tolerance on undelinted, seed should be removed when the 

subgroup tolerance is established.

Tomato subgroup 8-10A

Residue Chemistry Memo DP# 328984; W. Cutchin; 06/19/2006 

DER References: 44058730 and 44058731

Tolerances have been established for the combined residues of azoxystrobin and its Z-isomer in/on 

tomato at 0.2 ppm. A total of 16 field trials were conducted in Regions 1 (NJ; 1 trial), 2 (NC; 1 

trial), 3 (FL; 2 trials), 5 (IN; 1 trial), and 10 (CA; 11 trials). The results from the crop field trial on 

tomatoes have shown that the maximum combined residues in/on tomatoes treated eight times with 

Quadris 80WDG at 0.1 lb ai/A/application (equivalent to 1X the proposed rate) and collected 1 day

following the last application were 0.18 ppm. 

Pepper/eggplant subgroup 8-10B

Residue Chemistry Memo DP# 274312, G. J. Herndon, 07/10/2001

Residue Chemistry Memo DP# 328984, W. Cutchin, 06/19/2006 (PP# 1E06264) 

DER Reference: 45332502 

Tolerances have been established for the combined residues of azoxystrobin and its Z-isomer 

in/on vegetable, fruiting, group 8, except tomato at 2.0 ppm. The tolerances were established 

based on the results from eight supervised field trials on peppers (bell and non-bell) conducted in 

Regions 1 (NY; 2 trials), 2 (GA; 1 trial), 3 (FL; 2 trials), 5 (OH; 1 trial), 6 (TX; 1 trial), and 10 

(CA; 2 trials). Bell and non-bell pepper data (PP#1E6264) were used to establish the okra and 

eggplant tolerances as a result of a previous request from IR-4 (DP# 274312, G. Herndon, 

4/30/01). The results from the crop field trial on peppers have shown that the maximum residues 

in bell peppers and non-bell peppers treated six times with Quadris 80WDG at 0.25 lbs 

ai/A/application (equivalent to 1X the proposed rate) and collected 0 days following the last 

application were 0.40 ppm and 0.92 ppm, respectively. 

Note to PM: The existing separate tolerance on okra should be removed when the subgroup 

tolerance is established.

Dragon-fruit

Residue Chemistry Memo DP# 274312, G. J. Herndon, 07/10/2001

DER Reference: 45205606

Tolerances have been established for the combined residues of azoxystrobin and its Z-isomer 

in/on mango at 2 ppm. The tolerance was established based on the results from the supervised 

crop field trials on mango conducted in Region 13 (FL; 3 trials). The results from the crop field 

trials have shown that the maximum residues in mango treated six times with 80WG (containing 

80% a.i.) at 0.25 lbs ai/A/application (equivalent to 1X the proposed rate) and collected 0 days 

following the last application were 0.48 ppm. The mango tolerance of 2.0 ppm can be translated 

to dragon-fruit; both are classified as tropical fruit with inedible peels (ChemSAC 2/9/2011).
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 23 of 37

Wasabi

Residue Chemistry Memo DP# 285603, N. Dodd, 01/22/2003

Residue Chemistry Memo DP# 312949, W. Cutchin, 01/23/2006

DER References: 45736301, 46006901, and 46219201

IR-4 is proposing to extrapolate the established tolerances of azoxystrobin on the herb subgroup 

19A, fresh leaves at 50 ppm. In addition, IR-4 is requesting that application be allowed through 

chemigation for wasabi. The existing herb and spice tolerances were established using crop field 

trials (basil, chive and dill seed) conducted using foliar broadcast sprays at 0.25 lb 

ai/A/application with a maximum seasonal rate of 1.25 lb ai/A, with a pre-harvest interval of 0-

days. The use pattern proposed for wasabi is similar to the current use directions for herbs and 

spices except for addition of application through chemigation. The tolerances on the herb 

subgroup 19A, fresh leaves are adequate to cover a tolerance of 50 ppm for wasabi, fresh and the 

herb subgroup 19A, dried leaves at 260 ppm to establish tolerances on wasabi, dry (ChemSAC,

2/23/2011). The petitioner is required to submit a revised Section F to propose a tolerance for 

residues of azoxystrobin in/on wasabi, dry at 260 ppm. 

Conclusions. The existing azoxystrobin tolerances on onion, bulb; onion, green; tomato; grape;

strawberry; juneberry; lingonberry; salal; cotton, undelinted seed; canola, seed; crambe, seed;

flax, seed; rapeseed, seed; rapeseed, Indian; mustard, field seed; mustard, Indian, seed; 

sunflower, seed; safflower, seed; vegetable, fruiting, group 8, except tomato; fruit, citrus, group 

10; caneberry subgroup 13-A; and bushberry subgroup 13-B are sufficient to support the 

proposed revisions to tolerances. Adequate geographic representation and residue data are 

available.

860.1520 Processed Food and Feed

DER Reference: 48437101.der2.doc

Syngenta submitted a processing study for azoxystrobin on potato following postharvest 

treatment. One postharvest trial was conducted in Kimberley, ID, in 2009. Potatoes were grown 

on-site and mature potato tubers were harvested, placed in on-site storage for ~2 months, and 

then treated with a spray mixture containing a 3.00 lb ai/gal (360 g a.i./L) difenoconazole 

flowable suspension (FS) formulation, a 2.09 lb ai/gal (250 g a.i./L) azoxystrobin soluble 

concentrate (SC) formulation, and a 1.92 lb ai/gal (230 g a.i./L) fludioxonil SC formulation. The 

test mixture was applied as a postharvest treatment spray directed to tubers falling from a 

conveyor belt at 1X the application rate of 0.0091 lb azoxystrobin/2000 lb potatoes (4.1357 g 

azoxystrobin/2000 lb potatoes [0.46 g a.i./100 kg potatoes]) using water as the carrier. The 

delivery rate was 0.51 gal/2000 lb potatoes (0.21 L/100 kg potatoes). Potato samples were 

collected after the spray had dried on the day of application [0 days after application (DAA)] and 

processed into flakes, chips, and wet peel by the University of Idaho Food Technology Center 

(Caldwell, ID) using simulated commercial procedures. Adequate descriptions were provided of 

the processing procedures, including material balance summaries. 

Potato raw agricultural commodity (RAC) and processed fraction samples were analyzed for 

residues of azoxystrobin and its metabolite R230310 using modified Syngenta Method RAM 

305/03 (MRID 47096401; PMRA # 2044022), an LC/MS/MS method. This method has been 

reviewed previously and deemed acceptable for data gathering. The limit of quantitation (LOQ; 
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 24 of 37

determined as the lowest limit of method validation, LLMV) was 0.01 ppm for azoxystrobin and 

R230310 in all potato matrices. The method was verified prior to and in conjunction with 

sample analysis and is considered adequate based on acceptable method validation and 

concurrent recovery data. The fortification levels used in method validation and concurrent

method recovery were adequate to bracket expected residue levels.

The maximum storage durations of samples from collection/processing to analysis were 140 days 

(4.6 months) for potato (RAC), 209 days (6.9 months) for flakes, 222 days (7.3 months) for 

chips, and 166 days (5.5 months) for wet peel. Analysis took place between 0 and 3 days after 

extraction. Adequate storage stability data are available indicating that residues of azoxystrobin 

and R230310 are stable at <-15 C for at least 24 months in/on soybean meal, corn grits, carrot 

root, leaf lettuce, grain sorghum forage, orange oil, and orange juice (MRID 45738101; PMRA # 

956496). Additionally, data on file indicate residues of azoxystrobin and R230310 are stable for 

up to 2 years in cucumbers, apples, grapes, peaches, peanuts, pecans, rapeseed, tomatoes, 

bananas, and wheat grain (MRID 44452303; PMRA # 1191031). According to the OECD 

Guidelines for the Testing of Chemicals (Test No. 506, Adopted 16 October, 2007), if there is no 

observed decline of residues across the range of five different commodity categories (high water 

content, high oil content, high protein content, high starch content, and high acid content), then 

residues are stable in all commodities, and specific freezer storage stability data for processed 

foods are not needed. Therefore, there are no concerns regarding the stability of azoxystrobin 

and R230310 residues in any samples in this study.

Concentration of residues in potatoes treated with one postharvest treatment of azoxystrobin 

(4.1357 g azoxystrobin/2000 lb potatoes [0.46 g a.i./100 kg potatoes]) following processing was 

not observed in potato processed fractions. Mean residues of azoxystrobin were 0.938 ppm for 

potato tuber (RAC), <0.01 ppm for flakes, 0.0111 ppm for chips (resulting in a processing factor 

of 0.01x), and 0.846 ppm for wet peel (resulting in a processing factor of 0.90x). Residues of 

metabolite R230310 were below the LOQ (<0.01 ppm) in/on all samples of potato RAC, flakes, 

chips, and wet peel. Therefore, no processing factors were calculated for R230310. All of the 

processing factors calculated in this study were less than the maximum theoretical concentration 

factors of 4.7x for dried potatoes (flakes and granules) and 4.0x for processed waste (based on 

loss of water and separation of components; OPPTS 860.1520, Tables 2 and 3; DIR98-02, 

Section 10).

Table 8. Residue Data from Potato Processing Studies with Azoxystrobin.

RAC Processed 

Commodity

Total Rate DAA Residues (ppm) Processing Factor1,2

g a.i./

2000 

lb

lb a.i./

2000 lb

Azoxystrobin R230310 Total 

Residues

Azoxystrobin R230310 Total 

Residues

Potato Tubers

(RAC)

4.1357 0.0091 0 0.938 <0.01 <0.948 -- -- --

Flakes <0.01 <0.01 <0.02 <0.01x NC <0.02x

Chips 0.0111 <0.01 <0.0211 0.01x NC <0.02x

Wet peel 0.846 <0.01 <0.856 0.90x NC <0.90x

1 NC = Not calculated; residues were below the LOQ (<0.01 ppm for all in analytes) in the RAC and processed fraction.

2

Processing Factor = [Measured residue for analyte in the processed fraction] / [Measured residue for analyte in the RAC]. 

Conclusion: The submitted potato processing study is acceptable. Processing of the tuber RAC 
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 25 of 37

with quantifiable residues of azoxystrobin did not result in the concentration of residues in potato 

fractions (processing factors were all <1x). Residues of R230310 were below the LOQ in/on all 

samples of potato RAC, flakes, chips, and wet peel. Therefore, processing factors were not 

calculated. The observed concentration factors were less than the theoretical concentration 

factors.

Acceptable methods were used for the determination of residues of azoxystrobin and the Zisomer metabolite. The sample storage conditions and durations for azoxystrobin analyses are 

supported by adequate storage stability data. 

860.1650 Submittal of Analytical Reference Standards

Analytical standards for azoxystrobin and its Z-isomer are currently available in the EPA 

National Pesticide Standards Repository (personal communication with Charles Stafford, ACB, 

07/07/2011) with an expiration date of 11/30/2014.

860.1850 Confined Accumulation in Rotational Crops

PP#6F4762; DP#s 230634, 230635, 230636, and 230637, L. Kutney, 4/25/97

PP#9F6058; DP# 260134, 9/6/00, M. Nelson 

Adequate confined studies have previously been presented in PP#6F4762 and re-evaluated in 

PP#9F6058. Total radioactive residues, expressed as [14C]azoxystrobin equivalents, accumulated

at >0.01 ppm in the raw agricultural commodities of lettuce, radishes, and wheat planted in sandy 

loam soil 30, 200, and 365 days after treatment of the soil with [14C]azoxystrobin at 1.8 lb ai/A. 

Residues were highest in rotated crop commodities from the 30-day PBI and declined in 

subsequent PBIs. 

Azoxystrobin was identified in all rotated crop commodities at the 30-day PBI. In 30-day PBI 

samples, the Z-isomer was only identified in wheat forage and straw. Compound 42 was the 

major metabolite identified in 30-day PBI lettuce and wheat forage and straw. In 30-day PBI

radish roots, azoxystrobin was the major metabolite and in 30-day PBI radish tops, metabolites 

G2, N1, and N2 were the major metabolites. In 30-day PBI wheat grain, 14C-starch was found to 

account for the largest portion of radioactivity. Several conjugated metabolites (compound 42 

and the M, N, and O metabolites) of primary crop metabolites were identified, indicating that 

azoxystrobin is more extensively metabolized in rotational crops than in primary crops. HED has 

concluded that the residues of concern in rotational crops are parent and the Z-isomer.

860.1900 Field Accumulation in Rotational Crops

PP#6F4762; DP#s 230634, 230635, 230636, and 230637, 4/25/97, L. Kutney 

PP#9F6058; DP#s 283588 and 287062, N. Dodd, 2/6/03

PP#9F6058; DP# 298114, L. Cheng, 12/20/05

PP#s 6F7106 & 7F7198; DP# 334571 & 340016, W. Cutchin, 3/12/08

Limited field rotational crop studies, reflecting applications made to the primary crop at a 

seasonal rate of 0.8 lb ai/A, were initially submitted in PP#6F4762. Subsequently, additional 

limited field rotational crop studies, with applications made to the primary crop at seasonal rates 
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 26 of 37

of 1.6 or 2.0 lb ai/A, were submitted and reviewed in PP#9F6058. Under PP#s 6F7106 and 

7F7198, HED concluded that the following PBIs were appropriate to support a maximum 

seasonal application rate of 2.0 lb ai/A to rotated crops: 12 months for buckwheat, millet, oats 

and rye; and 36 days for the leafy vegetables (except Brassica) crop group; the Brassica leafy 

greens subgroup; the root vegetables subgroup; the tuberous and corm vegetable subgroup; and 

the leaves of root and tuber vegetables group. Crops with registered uses may be planted 

immediately after the last treatment unless otherwise specified. For crops not on the label, a 12-

month PBI must be observed unless otherwise specified. 

Conclusions: Because the proposed amended uses do not result in increased maximum seasonal 

application rates of azoxystrobin, no changes to the existing rotational crop restrictions are 

needed. The rotational crop restrictions on the label for EPA Reg. No. 100-1098 is adequate. 

860.1550 Proposed Tolerances

HED has determined that the residues of concern in/on crop commodities for tolerance 

expression and risk assessment purposes are azoxystrobin and its Z-isomer. The tolerance 

expression proposed by IR-4 for the proposed/revised tolerances is adequate. 

Adequate field trial data have been submitted for the postharvest use of tuberous and corm 

vegetables subgroup 1C. The OECD statistical calculation procedures was utilized for 

determining appropriate tolerance levels; see Appendix II for tolerance calculations. The 

petitioner should submit a revised section F reflecting the recommended tolerance for the

vegetable, tuberous and corm, subgroup 1C and the correct commodity definitions as presented 

in Table 9.

No changes to the existing tolerances for livestock commodities are needed as a result of the 

proposed uses.

There are Canadian and Codex MRLs for residues of azoxystrobin and its (Z)-isomer for most of 

the requested crops. The Codex MRLs (JMPR Report 2008) are based on US field trials, except 

for subgroup 8-10A and 8-10B which were conducted in Europe. Even though the Codex MRLs 

are based on US field trials, there is a slight difference between MRLs of Codex/US due in part

to the difference in the residue definition. The US residue definition includes both the 

predominant E isomer and the minor Z isomer. The Codex residue definition includes only the E 

isomer. The difference in Codex and US MRL estimates, based on the same data set, is based 

on the JMPR rounding procedures and the tendency to increase the estimate for small data sets.

The US and Codex MRLs are in harmony for subgroup 13-07A, strawberries, and sunflower 

seeds. The US and Codex MRLs are not in harmony for subgroup 13-07G; dragon-fruit 

(mango); onion, bulb dry and green; vegetable subgroup 8-10A; tuberous and corm vegetables 

subgroup 1C, and wasabi (herbs, fresh and dry).

HED recommends increasing the US MRLs for bushberry, subgroup 13-07B, cottonseed, citrus 

fruit, 10-10, fruit vine climbing 13-07F [grape], and pepper/eggplant 8-10B to harmonize with 

Codex.
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

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The US and Canadian MRLs are in harmony on all proposed crops, except subgroup 13-07F, 13-

07G, and cottonseed. There are no Canadian MRLs on cottonseed. Canadian MRLs were not 

established as subgroups for 13-07F and 13-07G and were established on grapes (3 ppm) and 

lowbush blueberries and ligonberries (subgroup 13-07B) at 3 ppm; US MRLs were established at 

1 ppm for 13-07F and at 10 ppm for 13-07G. The current post-harvest use on vegetable tuberous 

and corm, subgroup 1C recommends increasing the established US MRL on vegetable tuberous 

and corm, subgroup 1C to 8 ppm, which is in agreement with the proposed Canadian MRL. 

Citrus fruit:

The Codex MRL is based on field trials conducted in the USA. The MRL was estimated at 15 

ppm using the post-harvest dip results with one and two applications on the smaller citrus fruits 

(lemon, tangerine, and mandarin). The highest residue was 8.8 ppm. The 2008 JMPR Report 

(General Consideration 2.7) indicates that statistical evaluation of the data with the NAFTA 

calculator produced an estimate of 12.3 mg/kg. JMPR decided upon a higher value because of 

the small size of the data set. The US MRL (10.0 ppm) was based on field trial data that received 

preharvest as well as post harvest dip treatments on grapefruit, orange, and lemon samples; 

highest residue was 9.18 ppm. 

Berries and other small fruits:

The Codex MRL for berries and other small fruits except cranberry, grapes, and strawberry is 

based on field trials conducted in the USA (blackberry, raspberry, and blueberry). The estimated 

MRL is 5 ppm which is in harmony with US MRL for subgroup 13-07A. 

For grapes and strawberries, the Codex MRL is based on field trials conducted in the USA. The 

Codex estimated MRLs were 2 ppm (1 ppm US) and 10 ppm, respectively; highest residues were 

0.81 ppm for grapes and 4.5 ppm for strawberries. The 2008 JMPR Report (General 

Consideration 2.7) indicates that statistical evaluation of the data for grapes with the NAFTA 

calculator produced an estimate of 1.63 mg/kg, rounded to 2 mg/kg. The US tolerance is 1 ppm. 

A similar analysis for strawberries yielded an MRL estimate of 9.43 mg/kg, rounded to 10 

mg/kg. The US strawberry MRL is in agreement with Codex MRL. 

Mango

The Codex MRL is based on field trials conducted in the USA. The highest residue was 0.48 

ppm; the MRL was estimated at 0.7 ppm. The 2008 JMPR Report (General Consideration 2.7) 

indicates that statistical evaluation of the data with the NAFTA calculator produced an estimate 

of 1.67 mg/kg, which JMPR discarded because of the small data set and the use of professional 

judgment. The US MRL was established at 2.0 ppm 

Onion, bulb (dry) and green onion

The Codex MRL is based on field trials conducted in the USA which includes a trial with higher 

application rate (about 2x). The MRL was estimated at 10 ppm for bulb vegetables based on the 

result on spring onions; highest residue was 6.3 ppm. The 2008 JMPR Report (General 

Consideration 2.7) indicates that statistical evaluation of the data with the NAFTA calculator 

produced an estimate of 11.1 mg/kg, which JMPR decided to reduce to 10 mg/kg. The US MRL 

is established at 1 ppm for subgroup 3-07A and 7.5 ppm for subgroup 3-07B; highest residues 

were 0.67 and 6.9 ppm, respectively. 
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

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Vegetables Fruiting, subgroup 8-10A and 8-10B

The Codex MRL is based on field trials conducted on sweet pepper and tomatoes grown in an 

indoor environment in Europe. The data on sweet pepper and tomatoes were combined (n = 11). 

The maximum residue was 1.4 mg/kg on pepper. The 2008 JMPR Report (General 

Consideration 2.7) indicates that statistical evaluation of the data with the NAFTA calculator 

produced an estimate of 2.17 mg/kg. The MRL was estimated at 3 ppm for fruiting vegetables, 

other than cucurbits, except fungi and sweet corn. The US MRLs (0.2 tomatoes and 2.0 for 

group 8, except tomato) were based on trials conducted on tomatoes, bell peppers and nonbellpeppers; maximum residues were 0.18 and 0.40 and 0.92, respectively. 

Root and tuber vegetables

The Codex MRL is based on field trials conducted on beetroot, carrot, and radish conducted in 

the USA. Results of these trials were combined and the highest residue was 0.45 ppm. The MRL 

was estimated at 0.7 ppm for root and tuber vegetables. The 2008 JMPR Report (General 

Consideration 2.7) indicates that statistical evaluation of the data with the NAFTA calculator 

produced an estimate of 0.57 mg/kg based on 15 trials. JMPR rounded the value up slightly. 

The US MRL was established for vegetable, root subgroup 1A at 0.5 ppm (based on beetroot, 

carrot, and radish) and vegetable tuberous and corm, subgroup 1C at 0.03 ppm (based on potato); 

highest residues were 0.46 and 0.02 ppm, respectively. MRL was also established for potato at 

0.03 ppm. 

Oilseeds (Cotton seed)

The Codex MRL is based on field trials conducted on cotton as in-furrow and foliar treatments 

conducted in the USA. The results were combined and the maximum residue was 0.54 ppm. 

The 2008 JMPR Report (General Consideration 2.7) indicates that statistical evaluation of the 

data with the NAFTA calculator produced an estimate of 0.51 mg/kg based on 12 trials. JMPR 

selected an MRL of 0.7 mg/kg. The US highest residue was 0.62 ppm; tolerance was established 

at 0.6 ppm. 

Sunflower seed

The Codex MRL is based on field trials conducted on sunflower in the USA. The 2008 JMPR 

Report (General Consideration 2.7) indicates that statistical evaluation of the data with the 

NAFTA calculator produced an estimate of 0.31 mg/kg based on 6 trials. JMPR selected an 

MRL of 0.5 mg/kg and noted the unreliability of the statistical method because of the relatively 

small number of data points. The MRL was estimated at 0.5 ppm for sunflower seed; the 

Codex/US highest residue was 0.24 ppm. The US tolerance was established at 0.6 ppm. 

Herbs (For Wasabi-extrapolation from subgroup 19A, fresh and dry)

The Codex MRL is based on field trials conducted on basil, mint, and parsley conducted in the 

USA (chive was not included since the residues were much lower). The highest residue was 48 

ppm. The 2008 JMPR Report (General Consideration 2.7) indicates that statistical evaluation of 

the data with the NAFTA calculator produced an estimate of 52.3 mg/kg based on 7 trials. The 

MRL was estimated at 70 ppm for fresh herbs. The US MRL was estimated at 50 ppm for 

subgroup 19A, fresh; the highest residue on basil was 49 ppm. 

Dried herbs

The Codex MRL is based on field trials conducted on basil, chives, and parsley conducted in the 
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 29 of 37

USA (chive was not included since the residues were much lower). The highest residue was 235

ppm. The 2008 JMPR Report (General Consideration 2.7) indicates that statistical evaluation of 

the data with the NAFTA calculator produced an estimate of 297 (307) mg/kg based on 4 trials. 

The MRL was estimated at 300 ppm for dried herbs, except dry hops. The US MRL was 

estimated at 260 ppm for subgroup 19A, dried leaves based on dried basil (257 ppm).

Table 9. Tolerance Summary for Azoxystrobin

Commodity Established

Tolerance (ppm)

Proposed

Tolerance 

(ppm)

Recommended 

Tolerance 

(ppm)

Comments; Correct Commodity 

Definition

Onion, bulb, subgroup 3-

07A

Onion, bulb 1.0 1.0 1.0

Onion, green, subgroup 

3-07B

Onion, green 7.5 7.5 7.5

Vegetable, fruiting, 

subgroup 8-10A

Tomato 0.2 0.2 0.2 Tomato subgroup 8-10A

Vegetable, fruiting, 

subgroup 8-10B

Vegetable, 

fruiting, group 8, 

except tomato 2.0

2.0 3.0 Pepper/eggplant subgoup 8-10B

Tolerance increase to harmonize with 

Codex.

Fruit, citrus, group 10-10 Fruit, citrus, 

group 10 

10.0

10.0 15.0 Tolerance increase to harmonize with 

Codex.

Caneberry subgroup 13-

07A

Caneberry 

subgroup 13A

5.0 5.0

Bushberry subgroup 13-

07B

Bushberry 

subgroup 13B, 

Juneberry, 

Lingonberry, and 

Salal at 3.0 

3.0 5.0 Tolerance increase to harmonize with 

Codex.

Small fruit vine climbing, 

except fuzzy kiwifruit 

subgroup 13-07F

Grape 1.0 1.0 2.0 Fruit, small vine climbing, except 

fuzzy kiwifruit, subgroup 13-07F

Tolerance increase to harmonize with 

Codex.

Low growing berry 

subgroup 13-07G, except 

cranberry

Strawberry 10.0 10.0 10.0 Berry, low growing, subgroup 13-

07G, except cranberry

Rapeseed subgroup 20A Canola, seed 1.0 1.0 1.0

Sunflower subgroup 20B Safflower, seed 

and sunflower, 

seed 0.5

0.5 0.5

Cottonseed subgroup 20C Cotton, 

undelinted seed 

0.6

0.6 0.7 Tolerance increase to harmonize with 

Codex.

Wasabi Herb subgroup 

19A, fresh leaves 

50

50 50 Wasabi, fresh

Wasabi, dry Herb subgroup 

19A, dried leaves 

260

Not 

proposed

260 Wasabi, dry
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 30 of 37

Dragon-fruit Mango 2.0 2.0 2.0

Vegetable, tuberous and 

corm, subgroup 1C

0.03 6.0 8.0

References

DP#s: 218318 and 218448

Subject: PP No. 5F4541: New Chemical: Azoxystrobin (ICIA5504) in/on Grape RACs. 

Evaluation of Analytical Methods and Residue Data. CBTS Nos. 16051 & 16092.

From: J. Garbus

To: J. Bazuin/C. Giles-Parker

Dated: 3/19/96

MRIDs: 43678102-43678107, 43678193-43678195, 43678200-43678210 and 43694201-

43694206

DP#s: 226232

Subject: PP No. 5F4541: New Chemical: Azoxystrobin (ICIA5504) in/on Grape Rac's. 

Chemical No. 128810. Revised Sections B and F and Additional Field Trial 

Residue 

From: J. Garbus

To: D. McCall / B. Madden

Dated: 6/26/96

MRIDs: 440022-00 and 440022-01 

DP#s: 230634, 230635, 230636, and 230637

Subject: PP#6F4762. Azoxystrobin. Permanent Tolerance Petition for Use on Bananas, 

Peaches, Peanuts, Tomatoes, and Wheat. Evaluation of Analytical Methodology 

and Residue Data. Chemical# 128810. CBTS#: None.

From: L. Kutney

To: C. Giles-Parker, J. Bazuin, and B. Madden

Dated: 4/25/97

MRIDs: 44058715-44058730, 44058732-44058736, and 44073203-44073205

DP#s: 248887 and 249671

Subject: PP#7F4864. Tolerance Petition for use of Azoxystrobin on Cucurbits. 

PP#8F4995. Tolerance Petition for use of Azoxystrobin on Bananas, Potatoes, 

and Stone Fruits.

From: D. Dotson, M. Doherty, and Y. Donovan

To: C. Giles-Parker/J. Bazuin

Dated: 10/14/98

MRIDs: 44319305, 44452303, 44595105, 44595109-44595111, 44595114, 44595116, 

44613501, and 44613503
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 31 of 37

DP#: 251683

Subject: Azoxystrobin. Conclusions of the Metabolism Assessment Review Committee at 

Meeting of 11/10/98.

From: W. Wassell

To: G. F. Kramer, MARC

Dated: 12/30/98

MRIDs: None

DP#s: 249657 and 249668

Subject: PP# 7F4864. Tolerance Petition for use of Azoxystrobin on Peanut Hay, 

Pistachios, Rice, Tree Nuts, and Wheat. PP# 8F4995. Tolerance Petition for use 

of Azoxystrobin on Canola.

From: D. Dotson

To: C. Giles-Parker/J. Bazuin

Dated: 1/25/99

MRIDs: 44319303, 44319304, 44319306-44319308, 44452303, 44595104-44595108, 

44595113, 44595115 and 44613502

DP#: 254140

Subject: Azoxystrobin on Various Commodities. IR-4 Proposal For Reduced Residue 

Chemistry Data Set.

From: G. J. Herndon

To: H. Jamerson/R. Forrest

Dated: 3/17/99

MRIDs: 44915206-32 and 44983101

DP#s: 260134

Subject: PP#9F06058: Azoxystrobin. Evaluation of Residue Chemistry Data to Support 

Permanent Tolerances for Use of Azoxystrobin on Barley, Bulb Vegetables, 

Cilantro, Citrus Fruits, Corn, Cotton, Leafy Vegetables (except Brassica), Leaves 

of Root and Tuber Vegetables, Peanuts, Root and Tuber Vegetables, Soybeans, 

and Wild Rice; Higher Tolerances for the Fat and Meat Byproducts of Cattle, 

Goats, Horses, and Sheep; and, Apples (Inadvertent Residues).

From: M. J. Nelson

To: J. Bazuin/C. Giles-Parker

Dated: 09/06/2000

MRIDs: 449152-06 thru 449152-32; 449831-01

DP#s: 274312

Subject: PP No. 5F4541: New Chemical: Azoxystrobin (ICIA5504) in/on Grape RACs. 

Evaluation of Analytical Methods and Residue Data. CBTS Nos. 16051 & 16092.

From: G. Jeffrey Herndon

To: S. Brothers/R. Forrest 

Dated: 7/10/01

MRIDs: 45205604, 45205606, 45253901, and 45332502
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 32 of 37

DP#s: 279210

Subject: Azoxystrobin. Registration on Caneberry. Summary of Analytical Chemistry and 

Residue Data.

From: N. Dodd

To: S. Brothers/R. Forrest

Dated: 6/19/02

MRID: 45522301

DP#s: 285603, 285606, 285607 and 285608

Subject: PP#s 2E06489, 2E06495, 2E06375, and 2E06488. Azoxystrobin. IR-4 

Permanent Tolerance Petitions with Field Trials on Globe Artichoke, Asparagus, 

Basil, Broccoli, and Cabbage. Summary of Analytical Chemistry and Residue 

Data.

From: N. Dodd

To: S. Brothers/R. Forrest

Dated: 1/22/03

MRIDs: 45544901, 45730101, 45730102, 45731301, and 45736301 

DP#s: 283588 and 287062

Subject: PP#9F06058 and ID#s 000100-01098 and 000100-01093. Azoxystrobin. 

Condition-of-Registration Data, Including Bridging Data from the 50 WDG 

Formulation to the 2.08 FlC Formulation on Spinach, Garden Beet, Green Onion 

and Celery; Storage Stability Data; and Limited Field Rotational Crop Data.

From: N. Dodd

To: J. Bazuin/C. Giles-Parker

Dated: 2/6/03

MRIDs: 45640301, 45640302, 45640304-46560307, and 45738101

DP#: 298114

Subject: Azoxystrobin. Heritage Fungicide (EPA Reg. No. 100-1093. Condition-ofRegistration Data: Limited Field Rotational Crop Data. Petition Number 9F6058.

From: L. Cheng

To: J. Bazuin/C. Giles-Parker

Dated: 12/20/05

MRIDs: 45872401

DP#s: D312949, D312951, D312953, & D317291

Subject: Azoxystrobin Use on Dill, Chive, Sunflowers, Canola, and Post-Harvest Citrus. 

Review of Analytical Methods and Residue Data. Petition #’s 3E6637, 3E6749, 

4E6823, & 5E6916.

From: W. Cutchin

To: B. Madden/D. Rosenblatt

Dated: 1/23/06

MRIDs: 46006901, 46219201, 46046603, 46046604, 46046601, 46046602 & 46509101
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 33 of 37

DP#s: 328984

Subject: Azoxystrobin. Uses on Foliage of Legume Vegetables, Group 7; Fruiting 

Vegetables, Group 8 (Except Tomato); Pea and Bean, Succulent and Dried 

Shelled (Except Soybeans), Subgroups 6B and 6C; and Nongrass Animal Feeds, 

Group 18. Summary of Analytical Chemistry and Residue Data. Petition Number 

4E6823.

From: W. Cutchin

To: S. Jackson/D. Rosenblatt

Dated: 6/19/06 

MRIDs: 46006901, 46219201, 46046603, 46046604, 46046601, 46046602 & 46509101

DP#s: 334571 and 340016

Subject: Azoxystrobin. Petitions for the Establishment of Permanent Tolerances for 

New/Amended Uses on Non-grass Animal Feeds (Crop Group 18), Sorghum, 

Wheat, Cotton and Wild Rice. PP#s 6F7106 & 7F7198. Summary of Analytical 

Chemistry and Residue Data.

From: W. Cutchin

To: S. Piper and T. Kish/J. Bazuin

Dated: 3/12/08

MRIDs: 46924301-46924303, 47096401-47096402

Attachments: 

Appendix I - International Residue Limit Status Sheet

Appendix II - Tolerance Assessment Calculations

Template Version September 2005
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 34 of 37

Appendix I - International Residue Limit Status Sheet.

Azoxystrobin (PC Code 128810; 10/31/2011)

Summary of US and International Tolerances and Maximum Residue Limits 

Residue Definition:

US Canada Mexico2 Codex3

40 CFR 180. 507

Plants: sum of 

azoxystrobin, 

[methyl( E )-2-(2-(6-

(2-cyanophenoxy) 

pyrimidin-4-

yloxy)phenyl)-3-

methoxyacrylate], and 

the Z-isomer of 

azoxystrobin [methyl( 

Z )-2-(2-(6-(2-

cyanophenoxy)pyrimi

din-4-yloxy)phenyl)-3 

methoxyacrylate]

(αE)-methyl 2-[[6-(2-cyanophenoxy)-

4-

pyrimidinyl]oxy]-α-

(methoxymethylene)

benzeneacetate, including the isomer 

(Z)-

methyl 2-[[6-(2-cyanophenoxy)-4-

pyrimidinyl]

oxy]-α-

(methoxymethylene)benzeneacetate

Azoxystrobin. The 

residue is fat soluble.

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

US Canada Mexico2 Codex3

Berry, low growing, 

subgroup 13-07G, 

except cranberry

10.0

3.0 lowbush blueberries, 

lingonberries

5 berries and other 

small fruits, except 

cranberry, grapes and 

strawberry

10 strawberry 

Bushberry subgroup 13-

07B 5.0

3.0 bushberries (crop subgroup 

13-07B)

aronia berries, blueberries, 

buffalo currants, Chilean guava, 

currants, elderberries, European 

barberries, gooseberries, 

highbush blueberries, highbush 

cranberries, honeysuckle, 

huckleberries, jostaberries, 

lingonberries, lowbush 

blueberries, native currants, salal 

berries saskatoon berries 

(juneberries), sea buckthorn

5 berries and other 

small fruits, except 

cranberry, grapes and 

strawberry

Caneberry subgroup 13-

07A 5.0

5.0 caneberries (crop subgroup 

13-07A)

blackberries, loganberries, 

raspberries, wild raspberries

5 berries and other 

small fruits, except 

cranberry, grapes and 

strawberry

Cottonseed subgroup 

20C 0.7

0.7 cotton seed

Dragon-fruit 2.0 2 mangoes 0.7 mango 
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 35 of 37

Summary of US and International Tolerances and Maximum Residue Limits 

Residue Definition:

US Canada Mexico2 Codex3

Fruit, citrus, group 10-

10 15.0

10 citrus fruits ; Australian 

desert limes, Australian finger 

limes, Australian round limes, 

Brown River finger limes, 

calamondins, citrus citrons, 

citrus hybrids, grapefruits, 

Japanese summer grapefruits, 

kumquats, lemons, limes, 

Mediterranean mandarins, 

mount White limes, new Guinea 

wild limes, oranges, pummelos, 

Russell River limes, Satsuma 

mandarins, sweet limes, 

tachibana oranges, Tahiti limes, 

tangelos, tangerines, tangors,

trifoliate oranges, uniq fruits

15 citrus fruits

Fruit, small vine 

climbing, except fuzzy 

kiwifruit, subgroup 13-

07F

2.0

3 grapes 2 grapes

Onion, bulb, subgroup 

3-07A

1.0 1.0 dry bulb onions 10 bulb vegetables

Onion, green, subgroup 

3-07B 7.5 7.5 green onions

Pepper/eggplant 

subgroup 8-10B

3.0 2.0 bell peppers, eggplants, nonbell peppers, pepinos, pepper 

hybrids, 

3 fruiting vegetables 

other than cucurbits 

except mushrooms 

and sweet corn; 

30 peppers chili dried

Rapeseed subgroup 20A 1.0 1.0 rapeseeds (canola)

Sunflower subgroup 

20B

0.5 0.5 sunflower seeds 0.5 sunflower seed

Tomato subgroup 8-

10A

0.2

2.0 ground cherries, tomatillos 

0.2 tomatoes

0.6 tomato paste

3 fruiting vegetables 

other than cucurbits 

except mushrooms 

and sweet corn 

Vegetable, tuberous and 

corm, subgroup 1C 8.0

8.0 vegetable, tuberous and 

corm, subgroup 1C (proposed)

0.03 potatoes

1 root and tuber 

vegetables

Wasabi, fresh 50 50 Herbs (crop subgroup 19A; 

fresh leaves)

70 herbs

Wasabi, dry 260 260 Herbs (crop subgroup 19A; 

dried leaves)

300 dried herbs 

(except hops (dry))

Completed: M. Negussie; 10/31/2011

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.
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 36 of 37

Appendix II. Tolerance Assessment Calculations.

For the potato postharvest use, the OECD statistical calculation procedures were used for 

calculating the recommended tolerance. As specified in the OECD document, the average 

residue value was used. The rounding procedures specified in the OECD guideline were also 

used.

The datasets used to establish a tolerance for combined residues of azoxystrobin and its Z-isomer

for the potato postharvest use consisted of field trial data representing application rates of 4 g

ai/2000 lb potatoes (0.009 lb ai/2000 lb potatoes) at a 0-day PHI. 

The average residue values for the potato postharvest use which were used to calculate the 

tolerance are provided in Table II-1 and these values were entered in the OECD statistical 

calculation procedures. Using the OECD statistical calculation procedures, the recommended 

tolerance is 8 ppm (Figure II-1-3). The recommended tolerance (8 ppm) is higher than the 

proposed tolerance (6 ppm).

Table II-1. Residue data used to calculate tolerance for azoxystrobin on potato postharvest.

Regulator: EPA

Chemical: Azoxystrobin

Crop: Potato postharvest

PHI: 0-day

App. Rate: 4 g ai/2000 lb potatoes (0.009 lb ai/2000 lb potatoes)

Submitter: IR-4

MRID Citation: MRID 48437101

Average Combined Residues of Azoxystrobin and its Z-Isomer (ppm)

2.230

1.420

1.004

3.590

3.800

1.150

3.550

2.280
Azoxystrobin Summary of Analytical Chemistry and Residue Data DP#: 390152

Page 37 of 37

Figure II- 1. Tolerance spreadsheet summary of azoxystrobin field trial data for potato postharvest.

Azoxystrobin

Potato-post harvest

EPA

4 g ai/2000 lb potatoes; PHI=0

Total number of data (n) 8

Percentage of censored data 0%

Number of non-censored data 8

Lowest residue 1.004

Highest residue 3.800

Median residue 2.255

Mean 2.378

Standard deviation (SD) 1.147

Correction factor for censoring (CF) 1.000

Proposed MRL estimate

- Highest residue 3.800

- Mean + 4 SD 6.966

- CF x 3 Mean 7.134

Unrounded MRL 7.134

Rounded MRL 8