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would be deleted and replaced with a tolerance of 0.50 ppm in sugar beet. All commodities in 

subgroup 1B would then be labeled with a 1-day PHI. IR-4 has also proposed an expansion of

the established regional citrus registration to a national registration. There would then be no 

need to maintain the tolerances in citrus currently under 40CFR §180.544[c] (tolerances with 

regional registrations). IR-4 collected additional citrus fruit field trial data for this purpose. 

With these results, and the previously submitted citrus data (MRID #47556401), IR-4 has 

proposed the establishment of general (national) tolerances in citrus fruits (group 10-10) at 1.9 

ppm, in citrus oil (except lemon) at 100 ppm, and in lemon oil at 45 ppm. The established citrus 

tolerances with regional registrations under 40CFR §180.544[c] would be deleted. 

The proposed label directions for use on citrus fruits stipulate repeated foliar applications,

commencing when pests are first observed on the flushing leaves. Use rates are 0.12-0.25 lb ai 

per acre (lb ai/A) per application, up to a maximum of 1.0 lb ai/A per season. The minimum retreatment interval (RTI) is 14 days; the minimum PHI is 1 day. The proposed label directions for 

use on root vegetables (subgroup 1B) stipulate repeated foliar applications commencing at egg 

hatch, or when first signs of feeding are observed. Use rates are 0.12-0.25 lb ai per acre (lb ai/A) 

per application, up to a maximum of 1.0 lb ai/A per season (0.5 lb ai/A per season on radishes). 

The minimum RTI is not specified; the minimum PHI is 1 day. The label states that applications 

may include the use of an adjuvant for the proposed uses, and may be made using ground or 

aerial equipment on root vegetables; only ground applications are allowed on citrus fruits. 

Based on acceptable metabolism studies in cotton, apples, grapes and rice, the nature of 

methoxyfenozide residues in primary crops is adequately understood. HED concluded that the 

residue of concern (ROC) for both the tolerance expression and the risk assessment in primary 

crops (and drinking water) is methoxyfenozide. The qualitative nature of methoxyfenozide 

residues in livestock is also adequately understood, based on available ruminant and poultry 

metabolism studies. HED determined that the ROC is the parent compound in milk and 

ruminant tissues (except meat byproducts), and in poultry meat and fat. The ROCs in meat 

byproducts and eggs are methoxyfenozide and its metabolite, RH-141,518. The 

methoxyfenozide assessment team concurs with the previous findings regarding residues of 

concern. 

Adequate methods are available for enforcing the current tolerances for methoxyfenozide 

in primary crops, and animal commodities. Depending on the plant commodity, the limits of 

quantitation (LOQs) for methoxyfenozide in primary crop commodities are 0.010-0.050 ppm. In 

the submitted carrot and radish field trial studies, residues of methoxyfenozide were determined 

via one of the tolerance enforcement methods, Method TR 34-98-87 (Rohm and Haas Technical 

Report #34-98-87), with minor modifications. This method utilizes high performance liquid 

chromatography (HPLC), with either tandem mass spectrometric detection (LC/MS/MS) for 

analysis of carrots, or ultraviolet detection (HPLC/UV) for analysis of radishes. In the submitted 

citrus field trial and orange processing studies, residues of methoxyfenozide were determined via 

LC/MS/MS, using Dow AgroSciences Method GRM 02.25 (modified). The methods were

adequately validated in conjunction with the analysis of field trial and processing study samples. 
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The lowest levels of method validation (LLMVs) were 0.010 ppm in carrots and radishes, and 

0.050 ppm in each citrus commodity. 

Adequate multiresidue method testing data are available for the parent and its regulated 

metabolites. Based on these data, the FDA multiresidue methods are not suitable for analysis of

methoxyfenozide or its regulated metabolites. 

In conjunction with the field trial and processing studies, the petitioner submitted 

adequate storage stability data supporting the storage conditions and durations of the various 

requested commodities. These data indicate that methoxyfenozide is stable at ≤-20°C for 

intervals of up to 518 days in carrot roots, 253 days in radish roots, 629 days in citrus fruits, 405

days in orange dried pulp, and 403 days in orange juice. However, the data for orange oil 

indicated that there is the potential for a 24% decline in methoxyfenozide residues after 400 days 

of storage. Therefore, the residue data for citrus oil were corrected to account for decline during 

storage. 

Adequate field trial residue data are available for the representative commodities (carrot 

and radish) to support the establishment of a crop subgroup tolerance in root vegetables, except 

sugar beet (subgroup 1B), pending submission of a revised Section B prohibiting the use of 

agricultural adjuvants (for enhanced deposition, redistribution and weatherability) in tank mixes 

applied to subgroup 1B crops. The submitted carrot and radish field trials did not include the use 

of any adjuvants. The field trial data support a tolerance of 0.30 ppm in carrots, and a tolerance 

of 0.90 ppm in radishes; these tolerance levels vary by less than 5X. Ergo, the revocation of the 

established tolerance of 0.5 ppm in root vegetables (subgroup 1A), concomitant with the 

establishment of tolerances in sugar beet at 0.50 ppm, and in root vegetables, except sugar beet 

(subgroup 1B), at 0.90 ppm is appropriate. 

Adequate field trial residue data are also available for the representative commodities 

(oranges, lemons and grapefruit) to support the establishment of a crop group tolerance in citrus 

fruits (group 10-10). The current and previously submitted citrus field trial data adequately 

represent the number and geographic distribution for grapefruit, the number for lemons, and the 

geographic distribution for oranges, but not the number for oranges or geographic distribution for 

lemons recommended in OCSPP Residue Chemistry Test Guideline 860.1500. The guideline 

recommends 8 orange trials in Zone 3, but only 5 were conducted. The guideline recommends 4 

lemon trials in Zone 10 and 1 in Zone 3, but all 5 were conducted in Zone 10; however, HED 

considers the lemon field trial data adequate. Additionally, given that 20 of the 23 recommended 

citrus field trials were conducted, and that the HAFT (for all citrus) came from the original 

orange trials in Zone 10 (submitted with the previous petition for the regional use), and that all 

the required field trials for Zone 10 have been submitted, HED concludes that the data are 

adequate to support the proposed use (and national registration) of methoxyfenozide on citrus 

fruits. The field trial data support tolerances of 0.70, 1.5 and 3.0 ppm in grapefruit, lemons and 

oranges, respectively; these tolerance levels vary by less than 5X. Ergo, a tolerance of 3.0 ppm 

in citrus fruits (group 10-10) is appropriate. 
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The submitted orange processing study is adequate, and indicates that methoxyfenozide 

residues do not concentrate in juice (<0.2X), and concentrated only slightly in dried pulp (1.1X).

Therefore separate tolerances are not required in these citrus commodities. However, 

methoxyfenozide residues concentrated by 56X in orange oil, when samples were corrected for 

potential residue decline during storage. Based on the processing factor for oil, and the highest 

average field trial (HAFT) residues in oranges (1.67 ppm, from the previously submitted citrus 

field trials), the maximum expected residues in oil would be 93.5 ppm. Therefore, the revocation 

of the established regional tolerance of 100 ppm in citrus oil, concomitant with the establishment 

of a national tolerance in citrus oil at 100 ppm is appropriate. Because of the commercial 

importance of lemon oil, and the significantly lower HAFT in lemons (0.792 ppm, from the 

previously submitted citrus field trials), the petitioner has proposed a tolerance of 45 ppm in 

lemon oil. However, the Agency does not set tolerances in the oils of the various specific citrus 

fruits. Therefore, the establishment of a tolerance in lemon oil is precluded. 

Adequate livestock feeding studies are available for methoxyfenozide, and tolerances for 

livestock commodities were recently reassessed in conjunction with petitions for uses on grasses, 

peanuts, alfalfa and clover. Because the currently proposed uses will not alter the dietary burden 

of methoxyfenozide residues to livestock, reassessment of livestock tolerances is not required for 

this petition. 

The nature of methoxyfenozide residues in rotational crops is adequately understood, 

based on the adequate confined accumulation study. Methoxyfenozide is extensively 

metabolized in rotational crops. HED has determined that the ROCs (for risk assessment) in 

rotational crops are methoxyfenozide and its metabolites designated as RH-152,067, RH131,157, RH-152,071, and the free and conjugated forms of metabolite RH-117,236, including 

its glucose conjugate (RH-151,055) and its malonylglycosyl conjugate (RH-152,072). Adequate 

limited and extensive rotational crop field trials are available for methoxyfenozide, and these 

field trials support the rotational crop restrictions currently on methoxyfenozide labels. There 

are currently no tolerances in rotational crops. 

An analytical reference standard for methoxyfenozide, with an expiration date of 17 

October 2014, is currently available in the EPA National Pesticide Standards Repository

(NPSR). 

There are no Canadian maximum residue levels (MRLs) in any of the currently proposed 

commodities. Codex MRLs are established in citrus fruits at 0.7 mg/kg, in carrots at 0.5 mg/kg, 

and in radishes at 0.4 mg/kg. Harmonization of tolerances in the currently requested 

commodities is not possible, as the US and Codex use patterns differ. Additionally, the 

maximum residues in citrus fruits, and in radishes are greater than the corresponding Codex 

MRLs. HED’s recommended tolerances were determined using the Organization for Economic 

Cooperation and Development (OECD) tolerance calculation procedures (except for those in 

citrus oil).
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Regulatory Recommendations and Residue Chemistry Deficiencies

HED has examined the residue chemistry database for methoxyfenozide. Pending 

submission of revised Sections B and F, there are no residue chemistry issues that would 

preclude granting a registration for the proposed uses of methoxyfenozide (as Intrepid 2F). The 

submitted data support the following tolerances for residues of methoxyfenozide in/on the 

following commodities, at the levels listed below. 

Fruit, citrus, group 10-10 ....................................................................... 3.0 ppm

Citrus, oil............................................................................................... 100 ppm

Beet, sugar............................................................................................ 0.50 ppm

Vegetable, root, except sugar beet, subgroup 1B................................. 0.90 ppm

860.1200 Directions for Use

The product label for Intrepid 2F (EPA Registration #62719-442) should be amended to 

specify that adjuvants may not be added to spray mixtures applied to root vegetables, except 

sugar beet (subgroup 1B). The petitioner should also submit a revised Section B prohibiting the 

use of agricultural adjuvants in tank mixes applied to subgroup 1B crops. 

860.1550 Proposed Tolerances

The petitioner should submit a revised Section F to reflect the revisions to tolerances and 

commodity definitions, as presented above and in Table 9. 

Note to RD: According to HED’s Interim Guidance on Tolerance Expressions (S. 

Knizner; 27 May 2009), the tolerance expression for methoxyfenozide cited in 40CFR 

§180.544[a][1] should be revised to state: 

Tolerances are established for residues of methoxyfenozide, including 

its metabolites and degradates, in or on the commodities listed in the 

table below. Compliance with the tolerance levels specified below is to 

be determined by measuring only methoxyfenozide (3-methoxy-2-

methylbenzoic acid 2-(3,5-dimethylbenzoyl)-2-(1,1-dimethylethyl) 

hydrazide) in or on the commodity. 

Note to RD: A previous residue chemistry summary document for methoxyfenozide 

(D358341; D. Rate; 10 June 2009) refers to rotational crop tolerances cited in 40CFR 

§180.544[d][1 and 2]. As mentioned above, there are currently no tolerances listed in that 

section. HED recommends that RD investigate the disposition of these previously listed 

tolerances. 
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Background

Methoxyfenozide is a diacylhydrazine insecticide used on a variety of crops for control of 

armyworms and other lepidopterous pest species. Methoxyfenozide mimics the action of the 

molting hormone of lepidopterous larvae, causing the larvae to undergo an incomplete and 

premature molt, which ultimately results in their death. Methoxyfenozide is currently registered 

to Dow AgroSciences. The nomenclature and physicochemical properties of methoxyfenozide 

are presented below in Tables 1 and 2, respectively. 

TABLE 1 Methoxyfenozide Nomenclature. 

Chemical structure

Common name Methoxyfenozide

Company experimental name RH-2485

Molecular formula C22H28N2O3

Molecular weight 368.47

IUPAC name N-tert-butyl-N′-(3-methoxy-o-toluoyl)-3,5-xylohydrazide

CAS name 3-methoxy-2-methylbenzoic acid 2-(3,5-dimethylbenzoyl)-2-(1,1-

dimethylethyl)hydrazide

CAS registry number 161050-58-4

End-use product (EP) 2 lb ai/gal F (Intrepid 2F, EPA Registration #62719-442)

TABLE 2 Physicochemical Properties of Methoxyfenozide. 

Parameter Value Reference

Melting point/range (oC) 206.1-208 D231303; H. Podall; 19 May 1997

pH 7.0

Density (g/cm3) 0.740 ± 0.0081

Water solubility (mg/L at 20oC) 3.3

Solvent solubility (g/L at 20oC) N-heptane 1.87

Xylene 3.38

1,2-dichloroethane 36.72

Methanol 192.92

2-Propanol 50.22

Vapor pressure (25oC) 1.33 x 10-5Pa

Dissociation constant, pKa None

Octanol/water partition coefficient 

(Log [KOW])

3.72 ± 0.04

UV/visible absorption (max) ε 55313 at 203 nm European Commission; SANCO/10384/202 –

rev. 4; 7 October 2004

CH3 O

N

H

N

O

CH3

CH3

H3C CH3

H3C O

CH3
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860.1200 Directions for Use

Methoxyfenozide is currently registered for use on a wide variety of food and feed crops 

as a 2 lb/gal F formulation (Intrepid 2F, EPA Registration #62719-442). IR-4 is proposing new 

uses for this formulation on citrus fruits (crop group 10-10), and revised uses on root vegetables, 

except sugar beets (subgroup 1B). Draft supplemental labels for the Intrepid 2F were provided, 

and the proposed use directions are summarized in Table 3 (below).

TABLE 3 Summary of Use Directions for Methoxyfenozide. 

Application Type, 

Timing and 

Equipment1

Formulation

[EPA 

Registration #]

Use

Rate

(lb ai/A)

Max # of 

Uses per 

Season

Maximum

Seasonal Use

Rate (lb ai/A)

PHI

(Days)

Use Directions and 

Limitations

Citrus Fruits, Crop Group 10-10

Foliar applications 

at first sign of pests

on flushing leaves. 

Ground equipment 

only.

2 lb/gal F 

[62719-442]

0.12-

0.25

NS

2

1.0 1

The minimum RTI is 

14 days. Apply in a 

minimum of 20 GPA

3

. 

Root Vegetables, Except Sugar Beet, Crop Subgroup 1B

Foliar applications 

at egg hatch, or first 

sign of feeding 

damage. Ground or 

aerial equipment. 

2 lb/gal F 

[62719-442]

0.12-

0.25

NS 1.0 1

The minimum RTI is 

not specified. Apply 

in a minimum of 10 

GPA. Maximum 

seasonal use rate on 

radishes is 0.5 lb ai/A. 

1. The main label prohibits applications through any type of irrigation system. The supplemental labels allow for 

the inclusion of adjuvants in the spray mix. 

2. NS = Not Specified. However, based on the lowest single use rate, and maximum seasonal use rates, the implied 

maximum number of uses per season would be 4 on radishes, 8 on citrus fruits, and 8 on all root vegetables 

other than radishes. 

3. GPA = Gallons Per Acre. 

Conclusions: The supplemental label directions are adequate to allow for evaluation of 

the residue data relative to the submitted field trials. The available field trial data support the 

proposed use directions, except with respect to the use of adjuvants. The product label for 

Intrepid 2F should be amended to specify that adjuvants may not be added to spray mixtures 

applied to root vegetables, except sugar beet (subgroup 1B). 

860.1300 Nature of the Residue - Plants

HED Memo; D258034; W. Wassell; 23 July 1999

D251225; W. Wassell; 27 July 1999

D259989; W. Wassell; 8 August 2000

The nature of methoxyfenozide residues in primary crops is adequately understood, based 

on acceptable metabolism studies in cotton, apples, grapes and rice. Methoxyfenozide does not 

undergo extensive metabolism in primary crops. HED has determined that the ROC, for both the 
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tolerance expression and risk assessment in primary crops (and drinking water), is the parent 

compound only, methoxyfenozide. 

860.1300 Nature of the Residue - Livestock

HED Memo; D258034; W. Wassell; 23 July 1999

The nature of the residue in livestock is adequately understood, based on the available 

metabolism studies in lactating goats, and laying hens. HED has determined that the ROC in 

milk and ruminant tissues (other than liver and kidney) is parent compound; in ruminant liver 

and kidney it is methoxyfenozide and its RH-141,518 metabolite. The ROC in poultry meat 

(muscle) and fat is parent methoxyfenozide. The ROC in eggs, poultry liver, and poultry meat 

byproducts is methoxyfenozide and its metabolite, RH-141,518. 

860.1340 Residue Analytical Methods

DERs for MRIDs #47556401, 48402601 to -03

Enforcement Methods for Plant Commodities

The following HPLC/UV or LC/MS methods are available for enforcing tolerances of 

methoxyfenozide in primary crops: Method TR 34-96-88 for cotton commodities; Method TR 

34-98-87 for pome fruits; Method TR 34–00-38 for corn commodities; Method TR 34-00-107 

for tree nuts; Method TR 34-00-109 for stone fruits; and Method TR 34-99-74 for leafy and 

Brassica (Cole) vegetables, fruiting vegetables, grapes and raisins. Adequate method validation, 

radiovalidation, and independent laboratory validation (ILV) data have been provided for these 

methods. Successful petition method validation (PMV) trials were conducted on Methods TR 

34-96-88 and TR 34-98-87, and the Biological and Economic Analysis Division’s (BEAD’s)

Analytical Chemistry Branch (ACB) concluded that PMV trials were not required for the other 

methods, as they are sufficiently similar to the validated methods. 

For each of these methods, residues of methoxyfenozide are extracted with acidic 

aqueous methanol, filtered, and diluted with 10% sodium chloride. Extracts are then purified by 

sequential liquid-liquid partitioning with hexane and dichloromethane (DCM). Residues in the 

DCM fraction are further purified by elution through one or more of the following column types: 

basic alumina, silica gel, carbon, Florisil, or C18. Residues in the final eluate are concentrated, 

re-dissolved in acetonitrile (ACN)/water, and analyzed by reverse-phase HPLC using UV (240 

nm) or MS (m/z 367) with external standards. The LOQs for methoxyfenozide are 0.010-0.050

ppm, depending on the plant commodity. 

Data Collection Methods for Plant Commodities

Citrus Fruits: Residues of methoxyfenozide in citrus fruits (oranges, lemons and 

grapefruits), and processed orange commodities (MRID #47556401) were determined using an 

LC/MS/MS method which is a modified version of Dow AgroSciences Method GRM 02.25, 

Determination of Residue of Methoxyfenozide in High Moisture Crops by Liquid 
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Chromatography with Tandem Mass Spectrometry Detection. This method was previously 

reviewed in conjunction with a petition for use on soybeans (D316528; W. Cutchin; 25 April 

2006). The major modifications to the method included: 

1) The use of vacuum for filtration instead of centrifuge, 

2) an increase of the sample size from 0.050 g to 1.00 g, 

3) the addition of a concentration step prior to solid-phase extraction 

(SPE) cleanup, 

4) a change to the configuration of the SPE column, and 

5) the substitution of PFP-Propyl phase for the SB-C8 phase HPLC 

column, and use of 10mM ammonium acetate instead of formic 

acid in the mobile phase. 

A brief description of the method follows. Methoxyfenozide residues were extracted 

with 90% methanol/10% 0.1N hydrochloric acid, then filtered, and concentrated. An aliquot was 

then diluted with water, and residues were purified using a Phenomenex Strata-X SPE cartridge. 

After loading, the SPE cartridge was washed with 60% water/40% methanol/0.1% formic acid 

solution, and residues were then eluted with ACN. Residues were concentrated to dryness, and 

reconstituted in 50% ACN/50% 10mM ammonium acetate. The samples were then analyzed by 

LC/MS/MS using external standards and the m/z 339→149 ion transition for quantitation of 

residues. The LLMV in citrus fruits was 0.050 ppm. The reported LOQs for methoxyfenozide 

were 0.021, 0.018, 0.009 and 0.067 ppm in orange fruit, pulp, juice and oil, respectively. The 

reported limits of detection (LODs) were 0.007, 0.006, 0.003 and 0.022 ppm for orange fruit, 

pulp, juice and oil, respectively. The above method was validated prior to, and in conjunction 

with, the analysis of field trial samples. Control samples of oranges were fortified with 

methoxyfenozide at 0.050-5.0 ppm for method validation, and at 0.050-0.50 ppm for concurrent 

validation.

Samples of citrus fruits (MRID #48402601) were analyzed for methoxyfenozide using a 

modified version of Dow AgroSciences Method GRM 02.25. Modifications (provided in the 

study) were made to improve the performance of the method. Briefly, samples were 

homogenized with 90% methanol/10% 0.1N HCl, then shaken and centrifuged. An aliquot of 

the extract was diluted with water, and purified with an SPE plate. The plate was washed with 

60% water/40% methanol/0.1% formic acid, and eluted with ACN. The eluate was evaporated 

to dryness, and the residues were reconstituted in a 70% water/30% ACN mobile phase 

containing 0.1% formic acid. The purified extract was analyzed by LC/MS/MS. Based on 

recoveries of samples fortified at the LLMV, the LOD and LOQ in citrus fruits were stated as 

0.0072 and 0.022 ppm, respectively. 

Carrots: Residues of methoxyfenozide in carrots were determined using Rohm and Haas 

Technical Report #34-98-87, Tolerance Enforcement Method for Parent RH-2485 in Pome Fruit. 

Minor modifications which were implemented to improve efficiency did not negatively affect the 

performance of the method. Residues were extracted from carrots by blending and shaking with 

methanol/0.1N hydrochloric acid. The extract was purified by partitioning with hexane and 
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DCM. Quantification was achieved via LC/MS/MS. The method was validated at 0.010, 0.10, 

and 1.0 ppm of methoxyfenozide prior to sample analysis. The LOD and LOQ for 

methoxyfenozide were reported as 0.0028 and 0.0084 ppm, respectively. During sample 

analysis, untreated carrot roots were fortified with methoxyfenozide at 0.010, 0.10 and 1.0 ppm 

for determination of concurrent recoveries. 

Radishes: Residues of methoxyfenozide in radishes were determined using Rohm and 

Haas Technical Report #34-98-87, Tolerance Enforcement Method for Parent RH-2485 in Pome 

Fruit. Minor modifications which were implemented to improve efficiency did not negatively 

affect the performance of the method. Residues were extracted from radishes by blending with 

methanol/0.1N hydrochloric acid. The extract was purified by partitioning with hexane and 

DCM, and was further subjected to SPE cleanup using a silica gel column, followed by a carbon 

column. Residues were quantified via HPLC/UV. The method was validated at 0.010, 0.10 and 

1.0 ppm of methoxyfenozide prior to sample analysis. The LOD and LOQ for methoxyfenozide

were reported as 0.0034 and 0.010 ppm, respectively. The method suitability was demonstrated 

by concurrent recoveries, using samples fortified with methoxyfenozide at 0.10 ppm. 

Conclusions: The available methods are adequate for enforcing the established and 

recommended tolerances. Residues in citrus fruit and root vegetable commodities from the field 

trial and processing studies were determined using adequate data collection methods. 

860.1360 Multiresidue Methods

PP#8F5004 & PP#8F5006; D249438, D249458, D251218 & D251225; W. Wassell; 27 July 1999

Data concerning the recovery of methoxyfenozide using the FDA multiresidue method 

protocols (PAM Volume I) were previously submitted to, and reviewed by, HED. 

Methoxyfenozide was not recoverable by any of these procedures. The data were forwarded to 

FDA for evaluation, and the updating of PAM Volume I. 

860.1380 Storage Stability

DERs for MRIDs #47556401, 48402602 and -03

The storage durations and conditions for samples from the crop field trial and processing 

studies submitted to support the current petition are presented in Table 4. 

Citrus Fruits: Samples of oranges, lemons and grapefruits from the citrus field trials 

were stored at <-20°C for durations of up to 658 days prior to extraction for analysis (see Table 

4, below). To support this storage duration, a concurrent freezer storage stability study was 

conducted using control samples of oranges fortified with methoxyfenozide at 1.00 ppm. A 0-

day analysis was not conducted on the fortified samples prior to storage. The fortified samples 

were stored for a maximum interval of 629 days under the same conditions (<-20oC) as the field 

trial samples. At the end of the analytical phase, the stored samples were analyzed in triplicate,
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along with control samples freshly fortified with methoxyfenozide at 1.00 ppm. The average 

recovery from the stored fresh citrus samples (corrected for concurrent recoveries) was 99%. 

Although the field trial samples were stored for slightly longer (658 days) than the fortified 

samples in the storage stability study, the difference was relatively minor (29 additional days, 

<5% longer than the interval of the storage stability study), so the storage stability data support 

the storage conditions and durations of the samples from the citrus field trials. 

Samples of orange fruit, dried pulp, juice and oil from the citrus processing study were 

stored at ≤-20oC for durations of up to 420 days prior to analysis (see Table 4, below). To 

support these storage durations, a concurrent freezer storage stability study was conducted using 

control samples of orange fruit, dried pulp, juice and oil, each fortified with methoxyfenozide at 

1.00 ppm. A 0-day analysis was not conducted on the fortified samples prior to storage. The 

fortified samples were stored under the same conditions (≤-20oC) as the processing samples. At 

the end of the analytical phase, the stored samples were analyzed in triplicate, along with control 

samples freshly fortified with methoxyfenozide. The average recovery from the stored orange 

fruit, dried pulp, juice and oil samples (corrected for concurrent recoveries) were 99, 103, 109, 

and 76%, respectively. These data indicate that methoxyfenozide is stable at -20°C for intervals 

of up to 629 days in orange fruit, 405 days in orange dried pulp, and 403 days in orange juice. 

However, the 76% recovery from oil after 400 days indicates that some breakdown of residues 

may occur in frozen oil. However, the actual rate of decline could not be determined as the 

stored oil sample was only analyzed at one time point. These data support the sample storage 

conditions and durations for the citrus processing study; however, residues in oil we corrected to 

account for possible decline during storage. 

Carrots: The maximum storage duration for carrot samples was 491 days (see Table 4, 

below). Carrot storage stability samples were fortified with methoxyfenozide at 1.00 ppm. 

Storage stability samples were analyzed 518 days after fortification. Recoveries of 

methoxyfenozide from carrot samples fortified at 1.00 ppm averaged 90 ± 3% (n = 3). 

Radishes: Radish samples were stored frozen for durations of up to 253 days after

collection (see Table 4, below). A freezer storage stability study was conducted using radish 

samples fortified with 1.00 ppm methoxyfenozide, and stored for 468 days. The concurrent 

recovery of methoxyfenozide was 75% (n = 1). Recoveries from stored radish samples fortified

with methoxyfenozide at 1.00 ppm ranged from 75-77% (76 ± 1%, n= 3), so the average 

recovery (corrected for concurrent recovery) was 101%. 

TABLE 4 Summary of Storage Conditions. 

Matrix Storage Temperature

(°C)

Actual Storage Duration 

(Days)*

Interval of Demonstrated 

Storage Stability (Days)

Orange fruit <-20 658 629

Lemon fruit 621

Grapefruit 657

Orange dried pulp 411 405

Orange juice 413 403

Orange oil 420 400
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TABLE 4 Summary of Storage Conditions. 

Matrix Storage Temperature

(°C)

Actual Storage Duration 

(Days)*

Interval of Demonstrated 

Storage Stability (Days)

Carrot roots -37 to 0.2 491 518

Radish roots -37 to -6 253 468

* Interval from harvest to extraction for analysis. 

Conclusions: The available storage stability data are adequate, and support the storage 

conditions and durations for samples from the submitted root vegetable and citrus fruit field 

trials, and the orange processing study. Based on the decline in residues observed in citrus oil 

during frozen storage (24% decrease after 13 months), the residue data for citrus oil will be 

corrected to account for decline during storage. 

860.1400 Water, Fish, and Irrigated Crops

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

860.1460 Food Handling

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

860.1480 Meat, Milk, Poultry, and Eggs

Adequate livestock feeding studies are available for methoxyfenozide (D269969; M. 

Nelson; 7 August 2002), and methoxyfenozide residues in animal commodities were recently 

reassessed in conjunction with petitions for uses on citrus fruits (regional registration), dried 

shelled peas and beans (except soybeans), popcorn, and pomegranate (D358341; D. Rate; 10 

June 2009). The maximum reasonably balanced dietary burdens (MRBDBs) of 

methoxyfenozide residues to livestock were calculated at that time to be 35 ppm for beef cattle, 

54 ppm for dairy cattle, 7.7 ppm for poultry, and 0.2 ppm for swine. 

The only new livestock feedstuffs associated with the currently proposed uses are citrus 

dried pulp, and carrot culls. Based on recent changes in Agency guidance on calculating 

MRBDBs (ChemSAC memorandum; 30 June 2008), citrus dried pulp is generated in Florida 

(fresh market culls in California and Texas are disposed of as wet pulp). It is fed to beef and 

dairy cattle, and is used at a maximum of 10% in premixed ration supplements. Wet pulp is 

applied to local fields for livestock foraging. Carrot culls are generated in carrot growing areas, 

and are fed to local growing beef cattle, dairy cattle, and sheep. They are fed at a maximum of

10% in dairy cattle diets, and at <5% (not used, essentially) in beef cattle and sheep diets. 
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Conclusions: As the recommended tolerances in these livestock feedstuffs are 3 ppm or 

less, and because the feedstuffs are fed locally, and do not comprise substantial portions of 

livestock diets (≤10%), they will not significantly alter the dietary burden to livestock from

methoxyfenozide residues. Ergo, reassessment of livestock tolerances is not required for this 

petition.

860.1500 Crop Field Trials

DERs for MRIDs #48402601 to -03

Citrus Fruits (Crop Group 10-10)

Oranges, grapefruit and lemons: IR-4 has submitted field trial data for residues of 

methoxyfenozide in citrus fruits. 14 field trials were conducted (7 on oranges, 4 on grapefruit, 

and 3 on lemons) in the US, encompassing EPA regions 3 (FL; 5 orange, and 3 grapefruit), 6 

(TX; 1 orange), and 10 (CA; 1 orange, 1 grapefruit, 3 lemon) during the 2008 growing season. 

The number and geographic locations of the submitted trials, in combination with previously 

reviewed citrus data (MRID #47556401), do not satisfy the data requirements of OCSPP Residue 

Chemistry Test Guideline 860.1500 for a national registration. 

At each of the trial sites, methoxyfenozide (as Intrepid 2F) was applied to citrus trees as 4

foliar directed applications at rates of approximately 0.25 lb ai/A each, for total seasonal use 

rates of approximately 1.0 lb ai/A. A non-ionic surfactant (NIS) or crop oil concentrate (COC)

adjuvant was included in each tank mix at all trial sites. The applications were made at 12- to 

15-day RTIs, and marketable citrus fruit was collected at a PHI of 1 day. Additional samples 

(for the determination of residue decline characteristics) were also collected from the CA69 

orange trial at 3-, 7- and 14-day PHIs. 

The results from the current field trials (see Table 5, below) show that the maximum 

methoxyfenozide residue in citrus fruit was 0.658 ppm following total seasonal applications of 

approximately 1.0 lb ai/A, with a PHI of 1 day. The residue decline trial showed that there was 

no significant decline in residues over 14 days. The LLMV was 0.050 ppm. The reported LOD 

and LOQ were 0.0072 ppm and 0.022 ppm, respectively. 

TABLE 5 Summary of Residue Data from Citrus Field Trials with Methoxyfenozide. 

Commodity Total Use

Rate (lb ai/A)

PHI 

(Days)

Residue Levels (ppm)

n Min. Max. HAFT* Median Mean Std. Dev.

Field Trials from Current Submission (MRID #48402601)

Orange fruit 1.00-1.02 1 14 0.195 0.658 0.543 0.277 0.311 0.12

3 2 0.213 0.229 0.221 0.221 0.221 ---

7 2 0.159 0.190 0.175 0.175 0.175 ---

14 2 0.188 0.294 0.241 0.241 0.241 ---

Grapefruit fruit 0.99-1.01 1 8 0.136 0.312 0.283 0.246 0.226 0.06

Lemon fruit 0.99-1.02 1 6 0.191 0.388 0.349 0.308 0.291 0.07
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TABLE 5 Summary of Residue Data from Citrus Field Trials with Methoxyfenozide. 

Commodity Total Use

Rate (lb ai/A)

PHI 

(Days)

Residue Levels (ppm)

n Min. Max. HAFT* Median Mean Std. Dev.

Field Trials from Previous Submission (MRID #47556401)

Orange fruit 1.00-1.01 1 4 0.140 1.72 1.670 0.894 0.912 0.876

Lemon fruit 1.00 1 4 0.374 0.933 0.792 0.529 0.591 0.259

Grapefruit fruit 1.00-1.02 1 4 0.112 0.278 0.254 0.173 0.184 0.083

All citrus fruits 1.00-1.02 1 12 0.112 1.72 1.670 0.326 0.562 0.571

* HAFT = Highest Average Field Trial. 

Conclusions: The current and previously submitted citrus field trial data adequately 

represent the number and geographic distribution for grapefruit, the number for lemons, and the 

geographic distribution for oranges, but not the number for oranges or geographic distribution for 

lemons recommended in OCSPP Residue Chemistry Test Guideline 860.1500. The guideline 

recommends 8 orange trials in Zone 3, but only 5 were conducted. The guideline recommends 4 

lemon trials in Zone 10 and 1 in Zone 3, but all 5 were conducted in Zone 10; however, HED 

considers the lemon field trial data adequate. Additionally, given that 20 of the 23 recommended 

citrus field trials were conducted, and that the HAFT (for all citrus) came from the original 

orange trials in Zone 10 (submitted with the previous petition for the regional use), and that all 

the required field trials for Zone 10 have been submitted, HED concludes that the data are 

adequate to support the proposed use (and national registration) of methoxyfenozide on citrus 

fruits. The field trial data support tolerances of 0.70, 1.5 and 3.0 ppm in grapefruit, lemons and 

oranges, respectively; these tolerance levels vary by less than 5X. Ergo, a tolerance of 3.0 ppm 

in citrus fruits (group 10-10) is appropriate. A revised Section F should be submitted requesting 

a tolerance that concurs with HED’s recommendation. 

Root Vegetables, Except Sugar Beet (Crop Subgroup 1B)

Carrots: IR-4 has submitted field trial data for residues of methoxyfenozide in carrots. 

Eight field trials were conducted in the US, encompassing EPA regions 3 (FL; 1 trial), 5 (MI and 

WI; 1 trial each), 6 (TX; 1 trial) and 10 (CA and NM; 3 trials and 1 trial, respectively) during the 

2007-2008 growing seasons. 

At each of the trial sites, methoxyfenozide (as Intrepid 2F) was applied to carrot plants as

4 foliar applications at a target rate of 0.25 lb ai/A, for total seasonal use rates of approximately 

1.0 lb ai/A. Foliar broadcast applications were used at all trial sites except CA64, FL19 and 

NM07 (at these sites, foliar directed applications were made). Applications were made at 12- to 

16-day RTIs, and marketable carrots were collected at a PHI of 1 day. At trial CA48, additional 

samples were also collected at PHIs of 0, 3, 6, 7 and 10 days for the determination of residue 

decline characteristics. No spray adjuvants were used for any of the applications at any of the 

field trial sites. 

The results from these trials (see Table 6, below) show that the maximum 

methoxyfenozide residue in carrot roots was 0.13 ppm following total seasonal applications of 

approximately 1.0 lb ai/A, with a PHI of 1 day. All control samples contained <0.010 ppm 
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methoxyfenozide except for one sample at 0.0107 ppm from field trial FL19. The residue 

decline trial showed that methoxyfenozide decreased with increasing PHIs. 

TABLE 6 Summary of Residue Data from Carrot Field Trials with Methoxyfenozide. 

Commodity Total Use Rate

(lb ai/A)

PHI

(Days)

Residue Levels (ppm)

n Min. Max. HAFT* Median Mean Std. Dev.

Carrot roots 1.03 0 2 0.103 0.112 0.1075 0.1075 0.1075 --

1.007 - 1.03 1 16 0.0266 0.130 0.1245 0.0743 0.0737 0.0303

1.03 3 2 0.0716 0.0802 0.0759 0.0759 0.0759 --

1.03 6 2 0.0695 0.0805 0.0750 0.0750 0.0750 --

1.03 7 2 0.0388 0.0399 0.0394 0.0394 0.0394 --

1.03 10 2 0.0537 0.0604 0.0571 0.0571 0.0571 --

* HAFT = Highest Average Field Trial. 

Radishes: IR-4 has submitted field trial data for residues of methoxyfenozide in radishes. 

Five field trials were conducted in the US, encompassing EPA regions 1 (NY; 1 trial), 3 (FL; 2 

trials), 5 (WI; 1 trial) and 10 (CA; 1 trial) during the 2007-2008 growing seasons. 

At each of the trial sites, methoxyfenozide (as Intrepid 2F) was applied to radish plants as

2 foliar applications at a target rate of 0.25 lb ai/A, for total seasonal use rates of approximately 

0.5 lb ai/A. Foliar broadcast applications were used at all trial sites except FL20 and FL21, 

where foliar directed applications were made. Applications were made at 13- to 15-day RTIs,

and marketable radishes were collected at a PHI of 1 day. At trial CA47, additional samples 

were also collected at PHIs of 0, 3, 5, 7 and 9 days for the determination of residue decline 

characteristics. No spray adjuvants were used for any of the applications at any of the field trial 

sites. 

The results from these trials (see Table 7, below) show that the maximum 

methoxyfenozide residue in radish roots was 0.601 ppm following total seasonal applications of 

approximately 0.50 lb ai/A, with a PHI of 1 day. All control samples contained <0.010 ppm 

methoxyfenozide. The residue decline trial showed that there was no significant decline in 

residues over 9 days. 

TABLE 7 Summary of Residue Data from Radish Field Trials with Methoxyfenozide. 

Commodity Total Use Rate

(lbs ai/A)

PHI 

(Days)

Residue Levels (ppm)

n Min. Max. HAFT* Median Mean Std. Dev.

Radish roots 0.496 0 2 0.0384 0.0445 0.0415 0.0414 0.0415 --

0.496-0.520 1 10 0.0442 0.601 0.4525 0.1098 0.1894 0.1766

0.496 3 2 0.0643 0.0648 0.0646 0.0645 0.0646 --

0.496 5 2 0.0561 0.0676 0.0619 0.0619 0.0619 --

0.496 7 2 0.0487 0.0557 0.0522 0.0522 0.0522 --

0.496 9 2 0.0402 0.0486 0.0444 0.0444 0.0444 --

* HAFT = Highest Average Field Trial. 
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Conclusions: The carrot and radish field trial data adequately represent the numbers and 

geographic distributions recommended in OCSPP Residue Chemistry Test Guideline 860.1500. 

The field trial data support a tolerance of 0.30 ppm in carrots, and a tolerance of 0.90 ppm in 

radishes; these tolerance levels vary by less than 5X. Ergo, a tolerance of 0.90 ppm in root 

vegetables, except sugar beet (subgroup 1B), is appropriate. A revised Section F should be 

submitted requesting a tolerance that concurs with HED’s recommendation. The petitioner 

should also submit a revised Section B prohibiting the use of agricultural adjuvants in tank mixes 

applied to subgroup 1B crops. 

860.1520 Processed Food and Feed

DER for MRID #47556401

In conjunction with the citrus fruit field trials, IR-4 submitted a processing study with

oranges treated at approximately 1X the seasonal use rate. The study is discussed in the text, and 

the processing factors for methoxyfenozide residues in orange fruit, dried pulp, juice and oil are 

summarized in Table 8 (below). 

TABLE 8 Summary of Processing Factors for Methoxyfenozide in Citrus Commodities. 

RAC Processed Commodity Processing Factor

Orange Fruit (RAC) Not applicable. 

Dried pulp 1.1X

Orange juice <0.2X

Orange oil 56X

In a field trial conducted in CA during 2006, methoxyfenozide (as Intrepid 2F) was 

applied to orange trees at fruit maturity as a single foliar directed spray at the rate of 0.995 lb 

ai/A. This application rate is roughly 4X the maximum proposed single use rate, and 1X the 

maximum total seasonal use rate. The application was made using ground equipment in a 

volume of 100 GPA, and no adjuvants were used in the spray mix. Single control and treated 

bulk samples of oranges were harvested at a PHI of 3 days, and whole fruits were processed into 

dried pulp, juice, and oil using commercial processing procedures.

Samples of orange whole fruit, dried pulp, juice and oil were stored at ≤-20oC for 13.4-

13.8 months prior to analysis. The available storage stability data indicate that methoxyfenozide 

is stable in frozen citrus fruit, pulp and juice for this duration, but the study also showed a 

potential decline of 24% in methoxyfenozide residues in oil after 13.1 months of frozen storage. 

Therefore, the residues in oil were corrected to account for this decline. 

Methoxyfenozide residues were determined using an adequate LC/MS/MS method (Dow 

AgroSciences Method GRM 02.25, modified), which was validated in conjunction with the 

analysis of processing study samples. The LLMV was 0.050 ppm for each matrix, and the 

reported LOQs were 0.021 ppm in whole fruit, 0.018 ppm in dried pulp, 0.009 in juice, and 0.067 
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ppm in oil. The reported LODs were 0.007, 0.006, 0.003 and 0.022 ppm, respectively for whole 

fruit, pulp, juice and oil. 

Following a single foliar application of methoxyfenozide at approximately 1.0 lb ai/A, 

methoxyfenozide residues were 0.245 ppm in orange fruit, 0.269 ppm in dried pulp, <0.05 ppm 

in juice, and 10.4 ppm in oil. When corrected for potential decline during frozen storage, 

original residues in oil were 13.68 ppm. These data indicate that methoxyfenozide residues were 

reduced in orange juice (<0.2X), and concentrated only slightly in dried pulp (1.1X). However, 

residues concentrated substantially in citrus oil (56X). The theoretical citrus processing factors 

are 2X for juice and dried pulp, and 1000X for oil. 

Conclusions: The citrus processing study is adequate and indicates that separate 

tolerances are not required in orange juice and dried pulp. However, a separate tolerance is 

required in citrus oil. Based on the 56X processing factor for oil, and the HAFT residue of 1.67 

ppm (from the previously submitted citrus field trials) in citrus fruits, the maximum expected

residue in oil is 93.5 ppm. Therefore, a tolerance in citrus oil at 100 ppm is appropriate. 

Because of the commercial importance of lemon oil, and the significantly lower HAFT in lemons 

(0.792 ppm, from the previously submitted citrus field trials), the petitioner has proposed a 

tolerance of 45 ppm in lemon oil. However, the Agency does not set tolerances in the oils of the 

various specific citrus fruits. Therefore, the establishment of a tolerance in lemon oil is 

precluded. A revised Section F should be submitted requesting a tolerance that concurs with 

HED’s recommendation. 

860.1650 Submittal of Analytical Reference Standards

The analytical standard for methoxyfenozide (RH-112485), with an expiration date of 17

October 2014, is currently available in the EPA’s NPSR (personal communication from Dallas 

Wright of BEAD/ACB; 10 January 2011). Upon expiration of the current standard (and/or its 3 

metabolites), the registrant is required to resubmit a reasonable amount of the analytical 

reference standard for methoxyfenozide. The reference standard should be sent to the ACB, 

which is located at Fort Meade, MD. It should be sent to the attention of either Theresa Cole or 

Thuy Nguyen at the address listed below, along with a letter of transmittal. Please note that the 

full 9-digit Zip Code is mandatory, or the mail will be returned to the registrant. 

USEPA

National Pesticide Standards Repository

Analytical Chemistry Branch/BEAD/OPP

701 Mapes Road

Fort George G. Meade, MD 20755-5350

The letter of transmittal should include the assay of the standard, name of the analytical 

method used, a statement of principal impurities, purification procedures employed, storage 

requirements, and special precautions for safe handling. Replacement of standards may be 
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required periodically if supplies are exhausted, or if decomposition occurs during storage. 

Material Safety Data Sheets (MSDSs) must accompany all analytical standards as specified by 

the Occupational Safety and Health Administration (OSHA) in 29CFR§1910.1200. In addition 

to the parent compound, 3 metabolites (included in risk assessment) are currently available in the

NPSR, as listed below with their respective expiration dates. 

Methoxyfenozide metabolite J (RH-151055) 15 July 2014

Methoxyfenozide metabolite RH-117236 3 September 2013

Methoxyfenozide metabolite RH-141518 26 July 2013

860.1850 Confined Accumulation in Rotational Crops

HED Memo; D258034; W. Wassell; 23 July 1999

D251225; W. Wassell; 27 July 1999

The nature of methoxyfenozide residues in rotational crops is adequately understood, 

based on the available confined rotational crop study. Following three soil applications of 

[

14C]-methoxyfenozide at rates totaling 2.0 lb ai/A, total radioactive residues accumulated at 

≥0.01 ppm in mustard, radishes, and wheat planted 31, 91 and 364 days after the last application. 

Methoxyfenozide was highly metabolized in rotational crops by oxidation, demethylation and 

hydroxylation to non-conjugated metabolites, which were then conjugated with biomolecules,

yielding bound residues and precursors in the sugar synthesis pathway. 

HED concluded that the ROCs in rotational crops include methoxyfenozide, its free 

phenol metabolite (RH-117,236), conjugated forms of the phenol metabolite (RH-151,055 and 

RH-152,072), and the metabolites RH-152,067, RH-131,157 and RH-152,071. For enforcement 

purposes, the tolerance definition for rotated crops includes parent only in high-moisture crops,

and the combined residues of parent and metabolites RH-151,055, RH-152,072 and RH-117,236 

in low-moisture crops. Metabolites RH-152,067, RH-131,157 and RH-152,071 are also to be 

taken into account in risk assessments. There are currently no tolerances in rotational crops. 

860.1900 Field Accumulation in Rotational Crops

D322948; D. Rate; 2 June 2009

Label directions for methoxyfenozide currently list rotational crop restrictions specifying 

that crops with registered uses may be replanted at any time, and all other food or feed crops may 

be replanted 7 days after the last application. Adequate limited and extensive rotational crop 

field trials are available that support these rotational crop restrictions. There are currently no 

tolerances in rotational crops. 

Note to RD: A previous residue chemistry summary document for methoxyfenozide 

(D358341; D. Rate; 10 June 2009) refers to rotational crop tolerances cited in 40CFR 

§180.544[d][1 and 2]. As mentioned above, there are currently no tolerances listed in that 
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section. HED recommends that RD investigate the disposition of these previously listed 

tolerances. 

860.1550 Proposed Tolerances

Note to RD: According to HED’s Interim Guidance on Tolerance Expressions (S. 

Knizner; 27 May 2009), the tolerance expression for methoxyfenozide cited in 40CFR 

§180.544[a][1] should be revised to state: 

Tolerances are established for residues of methoxyfenozide, including 

its metabolites and degradates, in or on the commodities listed in the 

table below. Compliance with the tolerance levels specified below is to 

be determined by measuring only methoxyfenozide (3-methoxy-2-

methylbenzoic acid 2-(3,5-dimethylbenzoyl)-2-(1,1-dimethylethyl) 

hydrazide) in or on the commodity. 

For purposes of the tolerances expression, HED previously determined that the ROC is 

methoxyfenozide in primary crops, and in livestock commodities (except meat byproducts and 

eggs). The ROCs in eggs and meat byproducts are the parent and Metabolite RH-141,518. The 

tolerances proposed by IR-4 in the current petition are listed in Table 9 (below), alongside 

HED’s recommended tolerances. 

Adequate field trial residue data are available for the representative commodities (carrot 

and radish) to support the establishment of a crop subgroup tolerance in root vegetables, except 

sugar beet (subgroup 1B), pending submission of a revised Section B restricting tank mixes with 

agricultural adjuvants (for enhanced deposition, redistribution and weatherability) to use on 

citrus fruits only. The submitted carrot and radish field trials do not reflect the use of an 

adjuvant. The field trial data support a tolerance of 0.30 ppm in carrots, and a tolerance of 0.90

ppm in radishes; these tolerance levels vary by less than 5X. Ergo, the revocation of the 

established tolerance of 0.5 ppm in root vegetables (subgroup 1A), concomitant with the 

establishment of tolerances in sugar beet at 0.50 ppm, and in root vegetables, except sugar beet 

(subgroup 1B), at 0.90 ppm is appropriate. A revised Section F should be submitted requesting a 

tolerance that concurs with HED’s recommendation. The petitioner should also submit a revised 

Section B prohibiting the use of agricultural adjuvants in tank mixes applied to subgroup 1B

crops. 

Adequate field trial residue data are also available for the representative commodities 

(oranges, lemons and grapefruit) to support the establishment of a crop group tolerance in citrus 

fruits (group 10-10). The current and previously submitted citrus field trial data adequately 

represent the number and geographic distribution for grapefruit, the number for lemons, and the 

geographic distribution for oranges, but not the number for oranges or geographic distribution for 

lemons recommended in OCSPP Residue Chemistry Test Guideline 860.1500. The guideline 

recommends 8 orange trials in Zone 3, but only 5 were conducted. The guideline recommends 4 
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lemon trials in Zone 10 and 1 in Zone 3, but all 5 were conducted in Zone 10; however, HED 

considers the lemon field trial data adequate. Additionally, given that 20 of the 23 recommended 

citrus field trials were conducted, and that the HAFT (for all citrus) came from the original 

orange trials in Zone 10 (submitted with the previous petition for the regional use), and that all 

the required field trials for Zone 10 have been submitted, HED concludes that the data are 

adequate to support the proposed use (and national registration) of methoxyfenozide on citrus 

fruits. The field trial data support tolerances of 0.70, 1.5 and 3.0 ppm in grapefruit, lemons and 

oranges, respectively; these tolerance levels vary by less than 5X. Ergo, a tolerance of 3.0 ppm 

in citrus fruits (group 10-10) is appropriate. A revised Section F should be submitted listing the 

correct commodity definition, and requesting a tolerance that concurs with HED’s 

recommendation. 

The submitted orange processing study is adequate, and indicates that methoxyfenozide 

residues do not concentrate in juice (<0.2X), and concentrated only slightly in dried pulp (1.1X). 

Therefore separate tolerances are not required in these citrus commodities. However, 

methoxyfenozide residues concentrated by 56X in orange oil, when samples were corrected for 

potential residue decline during storage. Based on the processing factor for oil, and the HAFT 

residues in oranges (1.67 ppm), the maximum expected residues in oil would be 93.5 ppm. 

Therefore, the revocation of the established regional tolerance of 100 ppm in citrus oil,

concomitant with the establishment of a national tolerance in citrus oil at 100 ppm is appropriate. 

Because of the commercial importance of lemon oil, and the significantly lower HAFT in lemons 

(0.792 ppm, from the previously submitted citrus field trials), the petitioner has proposed a 

tolerance of 45 ppm in lemon oil. However, the Agency does not set tolerances in the oils of the 

various specific citrus fruits. Therefore, the establishment of a tolerance in lemon oil is 

precluded. A revised Section F should be submitted listing the correct commodity definition, 

and requesting a tolerance that concurs with HED’s recommendation. 

There are no Canadian MRLs in any of the currently proposed commodities. Codex 

MRLs are established in citrus fruits at 0.7 mg/kg, in carrots at 0.5 mg/kg, and in radishes at 0.4 

mg/kg. Harmonization of tolerances in the currently requested commodities is not possible, as 

the US and Codex use patterns differ. Additionally, the maximum residues in citrus fruits, and in 

radishes are greater than the corresponding Codex MRLs. HED’s recommended tolerances were 

determined using the OECD tolerance calculation procedures (except for those in citrus oils).

See Appendix II for the tolerance calculation data sets. 

TABLE 9 Tolerance Summary for Methoxyfenozide. 

Commodity Established/[Proposed]

Tolerance (ppm)

Recommended 

Tolerance (ppm)

Comments; Correct Commodity 

Definition

Tolerances Listed Under 40CFR §180.544[a][1]

Vegetable, root, subgroup 1A 0.5 None

Beet, sugar [0.5] 0.50

Vegetable, root, except sugar 

beet, subgroup 1B

[0.8] 0.90

Fruit, citrus, group 10 [1.9] 3.0 Fruit, citrus, group 10-10

Citrus, oil (except lemon) [100] 100 Citrus, oil
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TABLE 9 Tolerance Summary for Methoxyfenozide. 

Commodity Established/[Proposed]

Tolerance (ppm)

Recommended 

Tolerance (ppm)

Comments; Correct Commodity 

Definition

Lemon, oil [45] None The Agency does not set tolerances 

in the oils of the various specific 

citrus fruits. 

Tolerances Listed Under 40CFR §180.544[c]

Fruit, citrus, group 10 10 None Regional registration, for use in 

Citrus, oil 100 None states west of the Mississippi River. 

References

PP#8F5004 & PP#8F5006; Methoxyfenozide. Conclusions of the 13/JUL/1999 Meeting 

of the Metabolism Assessment Review Committee.; D258034; W. Wassell; 23 July 1999. 

PP# 8F5004 & PP#8F5006: Methoxyfenozide on Cotton and the Pome Fruit Crop 

Group. Evaluation of Metabolism Data, Residue Data, and Analytical Methodology.; D251225, 

D251218, D249458, D249438; W. Wassell; 27 July 1999. 

PP9F06033: Section 3 Request for Use of Methoxyfenozide on Grapes and Fruiting 

Vegetables. Review of Analytical Methods and Residue Chemistry Data.; D259989; M. Doherty; 

8 August 2000. 

PP#0F06213: Methoxyfenozide in/on Field Corn and Sweet Corn; Poultry Tolerances; 

and, Higher Tolerances on Other Selected Animal Commodities. Residue Chemistry Review.; 

D269969; M. Nelson; 7 August 2002. 

Methoxyfenozide in/on Various Rotational Crops. Residue Chemistry Review.; D269986, 

D274542; M. Nelson; 7 August 2002. 

METHOXYFENOZIDE Supplemental Human Health Risk Assessment for: PP#9F06033 -

Fruiting Vegetables (except Cucurbits) Crop Group; Grapes; Raisins; PP#9F06062 - Leafy and 

Cole (Brassica) Vegetables Crop Groups; PP#0F06201 - Rotational Crops; PP#0F06213 -

Field and Sweet Corn; Higher Milk/Fat /Mbyp; Add Poultry/Eggs; PP#1F06259 - Stone Fruits 

Crop Group; Prune; PP#1F06287 - Tree Nuts Crop Group, including Pistachio; Almond Hulls; 

PP#2E06382 - Globe Artichoke; and PP#2E06408 - Lychee, including Longan, Spanish Lime, 

Pulasan, and Rambutan.; D259549; M. Nelson; 7 August 2002. 

Methoxyfenozide. Use on Sweet Potato, Blueberry, Dry Bean, Grass, Peanut, Green 

Onion, Avocado, Guava, Alfalfa and Clover. Summary of Analytical Chemistry and Residue 

Data. Petition Numbers 6E7086, 7E7218, & 6F7135.; D331948; W. Cutchin; 18 December 

2007. 
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Revisions of Feedstuffs in Table 1 of OPPTS Test Guideline 860.1000 and Guidance on 

Constructing Maximum Reasonably Balanced Diets (MRBD); Chemistry Science Advisory 

Council (ChemSAC) memorandum; 30 June 2008. 

Methoxyfenozide. Petition for Uses and Tolerances on the Citrus Crop (Group 10), 

Dried Shelled Peas and Beans, except Soybean (Subgroup 6C), Popcorn, and Pomegranate. 

Summary of Analytical Chemistry and Residue Data.; D358341; D. Rate; 10 June 2009. 

Methoxyfenozide. Registrant’s Response to Conditional Registrations for Uses and/or 

Tolerances on Leaf Vegetables, Rotational Crops, Stone Fruits, and Poultry Commodities. 

Summary of Analytical Chemistry and Residue Data. Petition Numbers: 9F06062, 0F06201, 

0F06213, 1F06259.; D322948, D295721, D288924, D295680; D. Rate; 2 June 2009. 

Attachments

Appendix I - International Residue Limit Status sheet

Appendix II - Tolerance Assessment Calculations
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Appendix I International Residue Limit Status Sheet

Methoxyfenozide (PC Code 121027)

Summary of US Tolerances, and International Maximum Residue Limits.

Residue Definitions

US Canada Mexico 1 Codex

40CFR §180.544

Plants: Methoxyfenozide (3-methoxy-2-

methylbenzoic acid 2-(3,5-

dimethylbenzoyl)-2-(1,1-

dimethylethyl)hydrazide). 

Livestock: Combined residues of 

methoxyfenozide and its glucuronide 

metabolite, RH-141,518 (3-[2-(1,1-

dimethylethyl)-2-(3,5-dimethylbenzoyl)-

hydrazino]carbonyl-2-methylphenyl- β-Dglucopyranuronic acid). 

Plants/Livestock: 

Methoxyfenozide (3-methoxy-2-

methylbenzoic acid 2-(3,5-

dimethylbenzoyl)-2-(1,1-

dimethylethyl)hydrazide). 

Livestock kidney/liver:

Methoxyfenozide, and its

metabolite, 3-{[2-(1,1-

dimethylethyl)-2-(3,5-

dimethylbenzoyl)-

hydrazino]carbonyl}-2-

methylphenyl- β-Dglucopyranuronic acid. 

Methoxyfenozide 

(the residue is fatsoluble, but is

not classified as 

fat-soluble with 

respect to its 

distribution in 

milk). 

Commodity 2 Tolerance 

(ppm) 3

Maximum Residue Limit (mg/kg)

US Canada Mexico 1 Codex

Fruit, citrus, group 10-10 3.0 0.7 in citrus fruits

Citrus, oil 100

Vegetable, root, except sugar 

beet, subgroup 1B.

0.90 0.5 in carrot, 

0.4 in radish

Sugar, beet 0.50 0.3 in sugar beet

Completed: M. Negussie, 7 December 2011. 

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

2. Includes only commodities of interest for this action. 

3. Tolerance values are those recommended by HED, not those proposed by the petitioner. 
Methoxyfenozide Summary of Analytical Chemistry and Residue Data DP Barcode D396397

Page 25 of 29

Appendix II Tolerance Assessment Calculations

Figure II-1 Dataset and Tolerance Calculation for Methoxyfenozide Residues in Carrots. 

Residues (mg/kg)

0.084

0.054

0.125

0.027

0.069

0.083

0.047

0.097

Methoxyfenozide

Carrot

USA

1.00 lb ai/A, 1-day PHI

Total number of data (n) 8

Percentage of censored data 0%

Number of non-censored data 8

Lowest residue 0.027

Highest residue 0.125

Median residue 0.076

Mean 0.073

Standard deviation (SD) 0.031

Correction factor for censoring (CF) 1.000

Proposed MRL estimate

- Highest residue 0.125

- Mean + 4 SD 0.197

- CF x 3 Mean 0.220

Unrounded MRL 0.220

Rounded MRL 0.3
Methoxyfenozide Summary of Analytical Chemistry and Residue Data DP Barcode D396397

Page 26 of 29

Figure II-2 Dataset and Tolerance Calculation for Methoxyfenozide Residues in 

Radishes. 

Residues (mg/kg)

0.108

0.453

0.046

0.267

0.074

Methoxyfenozide

Radish

USA

0.50 lb ai/A, 1-day PHI

Total number of data (n) 5

Percentage of censored data 0%

Number of non-censored data 5

Lowest residue 0.046

Highest residue 0.453

Median residue 0.108

Mean 0.190

Standard deviation (SD) 0.170

Correction factor for censoring (CF) 1.000

Proposed MRL estimate

- Highest residue 0.453

- Mean + 4 SD 0.871

- CF x 3 Mean 0.569

Unrounded MRL 0.871

Rounded MRL 0.9

High uncertainty of MRL estimate.

[Small dataset]
Methoxyfenozide Summary of Analytical Chemistry and Residue Data DP Barcode D396397

Page 27 of 29

Figure II-3. Dataset and Tolerance Calculation for Methoxyfenozide Residues in 

Oranges. 

Residues (mg/kg)

0.323

0.258

0.207

0.250

0.314

0.543

0.280

0.154

1.670

Methoxyfenozide

Orange

USA

1.00 lb ai/A, 1-day PHI

Total number of data (n) 9

Percentage of censored data 0%

Number of non-censored data 9

Lowest residue 0.154

Highest residue 1.670

Median residue 0.280

Mean 0.444

Standard deviation (SD) 0.472

Correction factor for censoring (CF) 1.000

Proposed MRL estimate

- Highest residue 1.670

- Mean + 4 SD 2.333

- CF x 3 Mean 1.333

Unrounded MRL 2.333

Rounded MRL 3
Methoxyfenozide Summary of Analytical Chemistry and Residue Data DP Barcode D396397

Page 28 of 29

Figure II-4 Dataset and Tolerance Calculation for Methoxyfenozide Residues in Lemons. 

Residues (mg/kg)

0.321

0.204

0.349

0.391

0.792

Methoxyfenozide

Lemon

USA

1.00 lb ai/A, 1-day PHI

Total number of data (n) 5

Percentage of censored data 0%

Number of non-censored data 5

Lowest residue 0.204

Highest residue 0.792

Median residue 0.349

Mean 0.411

Standard deviation (SD) 0.224

Correction factor for censoring (CF) 1.000

Proposed MRL estimate

- Highest residue 0.792

- Mean + 4 SD 1.307

- CF x 3 Mean 1.234

Unrounded MRL 1.307

Rounded MRL 1.5

High uncertainty of MRL estimate.

[Small dataset]
Methoxyfenozide Summary of Analytical Chemistry and Residue Data DP Barcode D396397

Page 29 of 29

Figure II-5 Dataset and Tolerance Calculation for Methoxyfenozide Residues in 

Grapefruit. 

Residues (mg/kg)

0.283

0.216

0.263

0.141

0.254

0.115

Methoxyfenozide

Grapefruit

USA

1.00 lb ai/A, 1-day PHI

Total number of data (n) 6

Percentage of censored data 0%

Number of non-censored data 6

Lowest residue 0.115

Highest residue 0.283

Median residue 0.235

Mean 0.212

Standard deviation (SD) 0.069

Correction factor for censoring (CF) 1.000

Proposed MRL estimate

- Highest residue 0.283

- Mean + 4 SD 0.488

- CF x 3 Mean 0.636

Unrounded MRL 0.636

Rounded MRL 0.7

High uncertainty of MRL estimate.

[Small dataset]