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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION

MEMORANDUM

Date: 6/30/10

SUBJECT: Mefenoxam. Petition for Tolerances in Support of New Uses on Snap Beans and 

the Caneberry Subgroup, Expanded Uses on the Bulb and Green Onion Subgroups 

and the Bushberry Subgroup, and Amended Use on Spinach. Summary of 

Analytical Chemistry and Residue Data.

PC Code: 113502 DP Barcode: D371307

Decision No.: 416985 Registration Nos.: 100-801, 100-804, 100-1202

Petition No.: 9E7591 Regulatory Actions: Section 3 Registration/ 

Amended Section 3 Registration

Risk Assessment Type: NA Case No.: NA

TXR No.: NA CAS No.: 70630-17-0

MRID No.: See MRID Summary Table 40 CFR: 180.546 (Mefenoxam)

 

FROM: Nancy Dodd, Chemist

Risk Assessment Branch III

Health Effects Division (7509P)

THROUGH: Leung Cheng, Senior Chemist

Risk Assessment Branch III

Health Effects Division (7509P)

TO: Barbara Madden, RM#5

Registration Division (7505P)

MRID Summary Table

MRID No. Study Type Comments

47803101 860.1500 Snap Bean New DER; 47803101.der.doc 

47803102

47803103 860.1500 Caneberry New DER; 47803103.der.doc

47803104

47803105 860.1500 Spinach New DER; 47803105.der.doc

This document was originally prepared under contract by Dynamac Corporation (1901 Research 

Boulevard, Suite 220; Rockville, MD 20850). The document has been reviewed by the Health 

Effects Division (HED) and revised to reflect current Office of Pesticide Programs (OPP) 

policies.
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Executive Summary

Mefenoxam [methyl N-(2,6-dimethylphenyl)-N-(methoxyacetyl)-D-alaninate] belongs to the 

phenylamine class of systemic fungicides (Group 4). Phenylamides are effective against soilborne diseases caused by Pythium and Phytophthora and foliar diseases caused by Phycomycetes

(downy mildews) on a wide variety of crops. 

Mefenoxam is the enriched R-enantiomer of the fungicide metalaxyl, which is a racemic mixture 

of R- and S-enantiomers (also referred to as the D- and L-enantiomers, respectively). Metalaxyl 

is a List A chemical; the Residue Chemistry Chapter for the Metalaxyl Reregistration Eligibility

Decision (RED) Document was issued on 6/16/94. Mefenoxam has replaced metalaxyl in 

Syngenta Crop Protection, Inc. products. Because it is the most fungicidally active component of 

the mixture, it may be used at half the application rates of metalaxyl. HED has concluded (DP# 

223261, 4/24/96, L. Kutney) that the established tolerances for metalaxyl will be adequate to 

support the use of mefenoxam on the same crops provided that (1) the use rates for mefenoxam 

are one-half the rate of metalaxyl; (2) mefenoxam applications are made in the same way as for 

metalaxyl; and (3) the labels restrict the use of both pesticides concurrently on the same crop. 

The Interregional Research Project No. 4 (IR-4) has submitted a request for amended registration 

for three Syngenta products: a 4 lb ai/gal emulsifiable concentrate (EC) formulation, Ridomil 

Gold® EC (EPA Reg. No. 100-801); a 4 lb ai/gal liquid soluble concentrate (SL) formulation, 

Ridomil Gold® SL (EPA Reg. No. 100-1202); and a 5% wettable powder (WP) formulation, 

Ridomil Gold®/Copper (EPA Reg. No. 100-804). The 5% WP formulation is a multiple active 

ingredient (MAI) product containing 5% mefenoxam and 60% copper hydroxide. For the 4 lb

ai/gal EC and SL formulations, the petitioner is proposing to: (1) expand the registered use on 

onions to include additional crops that are now included in the bulb vegetable crop group 3-07; 

(2) reduce the preharvest interval (PHI) for spinach from 21 to 3 days; (3) expand the registered

foliar use of the 4 lb ai/gal EC and SL formulations on head and leaf lettuce to cover all members 

of the leafy vegetables group; (4) add new uses on the caneberry subgroup 13-07A; and (5) 

expand the registered use on blueberries to cover the bushberry subgroup 13-07B. HED notes

that mefenoxam is currently registered for use on legume vegetables and raspberries; however, 

the proposed uses reflect less restrictive use patterns than those currently registered. For the 5% 

WP formulation, the petitioner is proposing to: (1) expand the registered use on onions to 

include additional crops that are now included in the bulb vegetable crop group 3-07 and snap 

beans; (2) reduce the PHI for spinach from 21 to 3 days; (3) add new uses on snap beans; and (4) 

add new uses on the caneberry subgroup. 

The use patterns addressed herein reflect a combination of proposed and registered use directions 

for all crops except snap beans and caneberries. The 4 lb ai/gal EC and SL formulations are 

proposed/registered for preplant incorporated and/or at-planting soil applications to onions, leafy

vegetables, caneberries, and bushberries at 0.25-1.8 lb ai/A/application, for postemergence and/or 

post-planting soil applications to caneberries and bushberries at 1.8 lb ai/A/application, and for 

postemergence foliar application to leafy vegetables/spinach at 0.125 lb ai/A/application. The 

5% WP formulation is proposed/registered for one to four postemergence foliar applications to 

onions, spinach, snap beans, and caneberries at 0.1-0.125 lb ai/A/application, with applications 

generally to be made following soil application of the EC or SL formulation. The 

proposed/registered maximum seasonal rates for combined soil and foliar applications are 1.3 lb 
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ai/A for green bulb vegetables, 1.4 lb ai/A for spinach and snap beans, 1.5 lb ai/A for onions, , 

and 3.6 lb ai/A for caneberries and bushberries; and the proposed/registered PHIs are 10 and 7 

days for dry bulb and green onions, respectively, 7 days for leafy vegetables (except spinach), 3 

days for spinach, 6 days for snap beans, 45 days (soil application) and 0 days (foliar application)

for caneberries, and 0 days for blueberries. 

In support of the proposed/registered uses, IR-4 is proposing under PP#9E7591 the establishment 

of permanent tolerances for residues of the fungicide mefenoxam, (R) and (S)-2-[2,6-

dimethyl(phenyl)-methoxyacetylamine]-propionic acid methyl ester, and its metabolites 

containing the 2,6-dimethylaniline moiety, and N-(2-hydroxy methyl-6-methylphenyl)-N-

(methoxyacetyl)-alanine methyl ester, in/on the following raw agricultural commodities: 

Bean, snap, succulent..................................................................... 0.35 ppm

Caneberry, subgroup 13-07A......................................................... 0.80 ppm

Bushberry subgroup 13-07B ............................................................ 2.0 ppm

Onion, bulb, subgroup 3-07A .......................................................... 3.0 ppm

Onion, green, subgroup 3-07B....................................................... 10.0 ppm

Spinach............................................................................................. 8.0 ppm

IR-4 has also proposed that the established tolerance for lingonberry be removed when the 

tolerance for the bushberry subgroup is established. 

Tolerances for mefenoxam are established under 40 CFR §180.546 and are expressed in terms of 

combined residues of (R)- and (S)-2-[2,6-dimethyl(phenyl)-methoxyacetylamine]-propionic acid 

methyl ester and its metabolites containing the 2,6-dimethylaniline moiety, and N-(2-

hydroxymethyl-6-methylphenyl)-N-(methoxyacetyl)-alanine methyl ester, each expressed as 

mefenoxam equivalents. Tolerances are established on globe artichoke, fresh and dried herbs, 

and a variety of tropical fruits, and range 0.05-55 ppm.

Tolerances for metalaxyl are established under 40 CFR §180.408 and are expressed in terms of 

the combined residues of the fungicide metalaxyl [N-(2,6-dimethylphenyl)-N-(methoxyacetyl) 

alanine methyl ester], and its metabolites containing the 2,6-dimethylaniline moiety, and N-(2-

hydroxymethyl-6-methylphenyl)-N-(methoxyacetyl)-alanine methyl ester, each expressed as 

metalaxyl equivalents. The established tolerances for crop commodities ranged from 0.1-25 

ppm, and established tolerances for livestock commodities range from 0.02 ppm for milk to 0.4 

ppm for fat, kidney, and liver of cattle, goat, hog, horse, poultry, and sheep. In addition, a 

tolerance with regional registration has been established under 180.408(c) for papaya at 0.1 ppm, 

and tolerances for indirect or inadvertent residues of metalaxyl are established under 180.408(d) 

for barley, cereal grain, oat, and wheat commodities ranging from 0.2 ppm (grain) to 2.0 ppm

(forage and straw).

The registered uses for mefenoxam that are relevant to the subject petition are supported by the 

following metalaxyl tolerances: blueberry at 2.0 ppm, onion, bulb at 3.0 ppm; onion, green at 

10.0 ppm; and spinach at 10.0 ppm. In addition, a tolerance on vegetable, legume, group 6 is 

established at 0.2 ppm, and a tolerance on raspberry is established at 0.5 ppm.

The nature of the residue in plants and livestock is adequately understood for mefenoxam, based 

on metalaxyl metabolism studies on potato, grape, lettuce, goat, and hen. Metabolites can be 
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separated into four classes: (1) those containing a 2,6-dimethylaniline (2,6-DMA) moiety; (2) 

those containing a 2-hydroxymethyl-6-methylaniline (HMMA) moiety; (3) those containing a 

ring hydroxylated dimethylaniline (Ring-OH) moiety; and (4) those containing a benzoic acid 

moiety. The nature of the residue in rotational crops is adequately understood for mefenoxam 

based on confined rotational crop studies conducted with metalaxyl on lettuce, sugar beet, and 

wheat. Metabolism in rotated crops generally proceeds by the same pathways seen in primary

crops, resulting in the same four classes of metabolites.

HED originally concluded that the mefenoxam residues to be regulated for the tolerance 

expression and for dietary assessments would be as follows:

In plants: (R)- and (S)-2-[(2,6-dimethylphenyl)-methoxyacetylamino]-propionic acid 

methyl ester, its metabolites containing the 2,6-DMA moiety, and N-(2-hydroxymethyl6-methylphenyl)-N-(methoxyacetyl)alanine methyl ester (CGA-94689), each expressed 

as mefenoxam equivalents.

In livestock: (R)- and (S)-2-[(2,6-dimethylphenyl)-methoxyacetylamino]-propionic acid 

methyl ester, its metabolites containing the 2,6-DMA moiety, and its metabolites 

containing the HMMA moiety, each expressed as mefenoxam equivalents.

In rotational crops: (R)- and (S)-2-[(2,6-dimethylphenyl)-methoxyacetylamino]-

propionic acid methyl ester, its metabolites containing the 2,6-DMA moiety, and CGA94689, each expressed as mefenoxam equivalents, except that 2-[(methoxyacetyl)(2-

methoxy-1-methyl-2-oxoethyl)amino]-3-methylbenzoic acid (CGA-108905) would also 

be included in the risk assessment for cereal grain rotational crops and N-(3-hydroxy2,6-dimethylphenyl)-N-(methoxyacetyl)alanine methyl ester (CGA-100255) would be 

included in the risk assessment for leafy vegetable (Brassica and non-Brassica)

rotational crops.

The HED Risk Assessment Review Committee (RARC) subsequently determined (report dated 

2/14/07) that: (1) the residue to be regulated (in the tolerance expression) in plant and livestock 

commodities is (R)- and (S)-2-[(2,6-dimethylphenyl)-methoxyacetylamino]-propionic acid 

methyl ester; (2) the current/reassessed tolerance levels should be retained; (3) for risk 

assessment, the residues of concern in plant and livestock commodities are 

metalaxyl/mefenoxam, its metabolites containing the 2,6-DMA moiety, its metabolites 

containing the HMMA moiety, its metabolites containing the Ring-OH moiety, and its 

metabolites containing the benzoic acid moiety; and (4) the available residue chemistry data can 

be used and factors may be employed to estimate the total residues of concern in dietary risk 

assessments. 

There are no livestock feedstuffs associated with the proposed/registered uses on onions, leafy

vegetables/spinach, snap beans, caneberries, and bushberries. Therefore, no livestock 

metabolism data, enforcement methods, storage stability data, or feeding studies are required to 

support this petition.

The residue analytical methods available for tolerance enforcement in plant commodities are 

common moiety methods which determine residues of metalaxyl/mefenoxam that are convertible 

to 2,6-DMA. These methods include: (1) Method I in the Pesticide Analytical Manual (PAM),

Vol. II (Method AG-348) which determines residues in plant commodities using gas-liquid 

chromatography with alkali flame-ionization detection (GLC/AFID); and (2) Method AG-395 
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(sent to FDA for inclusion in PAM, Vol. II as Method III), an improved version of Method AG348, which determines residues in plant commodities using GLC with nitrogen-phosphorus 

detection (NPD). Neither Method AG-348 nor Method AG-395 distinguish between the R- and 

S-enantiomers of metalaxyl/mefenoxam; however, a confirmatory high performance liquid 

chromatography method with mass spectrometric detection that utilizes a chiral column (chiral 

LC/MS), Method 456-98, is available for the enantioselective determination of the D- and Lenantiomers of metalaxyl in crops. This method has been adequately validated by ACB/BEAD,

and a revised version of the method has been submitted for inclusion in PAM, Vol. II. 

HED has determined that the 2,6-DMA common moiety residue analytical methods available for 

tolerance enforcement and used for data collection will not adequately recover all of the 

metalaxyl/mefenoxam residues of concern in the current tolerance expressions. While these 

methods are adequate to recover residues of metalaxyl/mefenoxam per se, they will not 

adequately recover metabolites containing the HMMA moiety and may not adequately recover all 

metabolites containing the 2,6-DMA moiety with the certainty needed to set legal limits, nor are 

they likely to recover metabolites containing the Ring-OH moiety or the benzoic acid moiety. As 

a result, in addition to the changes to the tolerance expression and the residues of concern for risk 

assessment addressed above, the HED RARC determined that: (1) the multiresidue method 

PAM, Vol. I Section 302 (Protocol D), which completely recovers metalaxyl/mefenoxam per se,

is an adequate enforcement method for the determination of metalaxyl/mefenoxam per se in plant

and livestock commodities; and (2) all future metalaxyl/mefenoxam magnitude of the residue 

data should include (a) analysis for residues of parent only using the multiresidue method PAM, 

Vol. I Section 302 in order to establish more appropriate tolerance levels, and (b) analysis using a 

2,6-DMA common moiety method, including recovery data for parent, CGA-62826, and CGA94689, in order to refine dietary risk assessments.

Samples from the submitted snap bean and caneberry trials were initially analyzed for residues of 

mefenoxam per se using a chiral LC/MS method, Method 456-98. Samples of spinach from the 

submitted field trials and selected samples of snap bean and caneberries were analyzed for 

combined residues of mefenoxam/metalaxyl, and metabolites convertible to 2,6-DMA using a 

gas chromatography (GC)/MS method, defined by working method numbers YARL-0601A 

(caneberry), -0601C (snap bean), and -0601D (spinach) which was derived, with minor 

modifications, from Method AG-395. The data collection methods were adequate for data 

collection based on acceptable method validation and concurrent recovery data for mefenoxam. 

The lowest level of method validation (LLMV) was 0.05 ppm for snap bean and caneberries 

using Method 456-98, and the LLMVs were 0.1 ppm for spinach and 0.05 ppm for snap bean and 

caneberries using Methods YARL-0601A, -0601C, and -0601D.

The study results for snap bean and caneberry, reflecting the original analysis for mefenoxam 

only and re-analysis of the selected field trial samples for parent + metabolites, were presented to 

HED’s Chemistry Science Advisory Council (ChemSAC) with a request to use conversion 

factors (calculated by dividing the residues obtained on re-analysis of certain field trial samples 

by the original values) to calculate residues in the remaining field trial samples for setting residue 

values for the risk assessment. The calculated conversion factors are: for snap beans, 1x for 0-

day preharvest interval (PHI), 1.8x for the 6- to 7-day PHI, and 3x for the 13- to 14-day PHI; and 

1.3x for caneberries. The ChemSAC agreed (see minutes of 2/25/09 meeting) that parent + 

metabolites to parent ratios could be used to estimate residue levels for risk assessments in snap 
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beans and caneberries, with the provision that these ratios would not necessarily be 

correct/adequate for these commodities for future risk assessments if refinements were necessary. 

The submitted crop field trial studies are supported by adequate storage stability data. 

Pending amendment of the proposed labels, adequate field trial data have been submitted for 

snap beans, and adequate data have been submitted for spinach treated with a soil application of 

the EC or SL formulation followed by foliar application of the WP formulation. For caneberries, 

an additional field trial conducted in Zone 5 or 6 and including residue decline data is required as 

a condition of registration; the proposed use must also be amended. The submitted data used to 

determine tolerances for snap bean and caneberries reflected analysis of samples for mefenoxam 

per se; the data for spinach reflected analysis for combined residues of mefenoxam/metalaxyl 

and metabolites convertible to 2,6-DMA. The crop field trial data for spinach will support a 

reduction in PHI from 21 days to 3 days, pending label amendments. Data are not available to 

support expanded foliar use of the 4 lb ai/gal EC and SL formulations on spinach or other 

members of the leafy vegetables group. The submitted crop field trial data for spinach will 

support a tolerance of 8.0 ppm for spinach; however, because the submitted data are not 

representative of all registered uses of mefenoxam on spinach, HED recommends against 

establishing a reduced tolerance for mefenoxam on spinach. The existing tolerance of 10 ppm

for spinach, established under 40 CFR §180.408, is appropriate. The proposed tolerances for 

snap bean and the caneberry subgroup are too high; tolerances should be established at 0.20 ppm 

for snap bean and 0.70 ppm for caneberry subgroup 13-07A.

 

Adequate crop field trial data for metalaxyl are available to support expanded use of mefenoxam 

on members of the bulb and green onion subgroups and bushberry subgroup. The available data 

will support establishment of the proposed tolerances for residues of mefenoxam in/on onion, 

bulb, subgroup 3-07A at 10 ppm; onion, green, subgroup 3-07B at 3.0 ppm; and bushberry

subgroup 13-07B at 2.0 ppm. In conjunction with establishment of the proposed tolerance for the

bushberry subgroup, the mefenoxam tolerance for lingonberry can be removed.

Adequate field rotational crop data are available to support the established plantback intervals for 

mefenoxam.

Codex MRLs, expressed in terms of metalaxyl per se for plant commodities, are established for 

spinach at 0.1 and onion at 0.03 ppm. Canadian (Pest Management Regulatory Agency; PMRA) 

MRLs for mefenoxam (metalaxyl-M) are covered by MRLs established for metalaxyl, the 

unresolved isomeric mixture, which are expressed in terms of N-(2,6-dimethylphenyl)-N-

(methoxyacetyl)-DL-alanine methyl ester, including metabolites that can be converted to the 2,6-

dimethylaniline moiety, calculated as metalaxyl equivalents. Canadian MRLs are established for 

spinach at 10 ppm, bulb onion at 3.0 ppm, green onion at 10 ppm, bean at 0.2 ppm, raspberry at 

0.2 ppm, and blueberry at 2.0 ppm. No Mexican MRLs are established for mefenoxam or 

metalaxyl. With the adoption of the tolerance expression recommended by the RARC, the U.S. 

tolerance expression will be in harmonization with Codex MRLs but not with PMRA MRLs. 
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Regulatory Recommendations and Residue Chemistry Deficiencies

HED has examined the residue chemistry database for mefenoxam and metalaxyl. Pending 

submission of a revised Section B (see requirements under Directions for Use) and a revised 

Section F (see requirements under Proposed Tolerances), there are no residue chemistry issues 

that would preclude granting full registration for the requested uses of mefenoxam on members 

of the bulb and green onion subgroups, spinach, snap beans, and bushberry subgroup, or 

conditional registration for the requested use on the caneberry subgroup. Tolerances for residues 

of mefenoxam per se are recommended as follow: 

Bean, snap, succulent..................................................................... 0.20 ppm

Caneberry subgroup 13-07A.......................................................... 0.70 ppm

Bushberry subgroup 13-07B ............................................................ 2.0 ppm

Onion, bulb, subgroup 3-07A .......................................................... 3.0 ppm

Onion, green, subgroup 3-07B.......................................................... 10 ppm

Spinach.............................................................................................. 10 ppm

As a condition of registration, additional crop field trial data are required for caneberries (see

requirements under Crop Field Trials).

In the absence of supporting crop field trial data, HED recommends against expanding the 

registered foliar uses of the 4 lb ai/gal EC and SL formulations on head and leaf lettuce to 

include spinach or any other members of the leafy vegetables except Brassica crop group.

A human health risk assessment is forthcoming.

Note to PM: Based on the tolerance expressions recommended by HED’s Risk Assessment 

Review Committee (2/14/07, W. Britton) and by HED in the metalaxyl/mefenoxam 

registration review (DP#368461, N. Dodd, 4/13/10), and to be consistent with Codex, the 

tolerance expression for mefenoxam should be revised according to HED’s Interim 

Guidance on Tolerance Expressions (5/27/09, S. Knizner) to state:

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

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

levels specified below is to be determined by measuring only metalaxyl (methyl N-(2,6-

dimethylphenyl)-N-(methoxyacetyl)-DL-alaninate).”

Note to PM: When the recommended tolerance on Bushberry subgroup 13-07B is 

established, the tolerance for lingonberry should be removed.
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860.1200 Directions for Use

A revised Section B must be submitted reflecting the following changes to the proposed use 

directions.

For onions:

 Since the WP label for bulb onions indicates a maximum of 0.4 lb ai/A/season of foliarapplied mefenoxam, the proposed use directions for the 4 lb ai/gal EC and SL

formulations should be revised to reflect the following maximum seasonal rate for bulb 

onion: “Do not exceed the equivalent of 1.0 lb ai/A per crop of soil-applied and 0.4 lb 

ai/A per crop of foliar-applied mefenoxam-containing products.”

 The proposed use directions for the 5% WP formulation should be revised to reflect the 

following maximum seasonal rates: (1) for bulb onion, “Do not exceed the equivalent 

of 1.0 lb ai/A per crop of soil-applied and 0.4 lb ai/A per crop of foliar-applied 

mefenoxam-containing products”; and (2) for green onion, “Do not exceed the 

equivalent of 1.0 lb ai/A per crop of soil-applied and 0.3 lb ai/A per crop of foliarapplied mefenoxam-containing products.”

For leafy vegetables/spinach:

 The proposed labels for Leafy Vegetables and Spinach Only must be revised. The 3-day

PHI for spinach can be applied only to application types and rates supported by the 3-day

PHI data (i.e., soil application at 1.0 lb ai/A/season and foliar application at 0.25 lb 

ai/A/season). Soil application of the EC formulation can be translated to the SL

formulation. Based on the available data for spinach at the proposed 3-day PHI, the 

proposed use directions for Spinach Only should be revised to specify soil surface 

application of the EC or SL formulations and foliar directed or broadcast spray

applications of the WP formulation, and to specify the following maximum seasonal 

rates: “Do not exceed the equivalent of 1.0 lb ai/A per crop of soil-applied mefenoxam 

containing products at planting and 0.25 lb ai/A of foliar-applied mefenoxam containing 

products.” The proposed changes to the existing Leafy Vegetables section of the existing 

labels to establish a 3-day PHI for spinach should be removed.

 For the 4 lb ai/gal EC and SL formulations, spinach and all other members of the leafy

vegetables except Brassica crop group, except head and leaf lettuce, must be removed 

from the use directions for Part 2 of the proposed label; the reference to Part 2 of the label 

that appears in Part 1 should be revised accordingly. 

 On the 5% WP formulation label, the statement referring to a 21-day PHI for spinach 

should be removed.

 The proposed use directions for all three products must be amended to specify that no 

adjuvants may be added to spray mixtures for foliar use on spinach.

 When HED approved the registered use of the 4 lb ai/gal EC formulation on head and leaf 

lettuce (DP# 324493, 3/17/06, L. Cheng), certain label revisions were required which 

have not been made. These revisions also apply to the label for the 4 lb ai/gal SL

formulation. As previously required under DP# 324493, Part 1 of the labels for the 4 lb 

ai/gal EC and SL formulations should be revised to specify that no more than one soildirected application may be made, and Part 2 should be revised to specify a maximum of

4 foliar-directed applications.
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Snap Beans: 

 The proposed use directions for the 5% WP formulation must be revised to specify a 

maximum of two applications per season at 0.1 lb ai/A/application and to reflect the 

following maximum seasonal rate for snap bean: “Do not exceed the equivalent of 0.5 lb 

ai/A per crop of soil-applied mefenoxam containing products at planting and 0.2 lb ai/A 

per crop of foliar-applied mefenoxam-containing products.”

 The proposed use directions for the 5% WP formulation must be revised to propose a 7-

day preharvest interval (PHI). Four of eight field trials have a 7-day PHI and four have a 

6-day PHI.

 The proposed use directions must be amended to specify that no adjuvants may be added 

to spray mixtures for foliar use on snap beans.

Caneberries:

 The proposed use directions for the 4 lb ai/gal EC and SL formulations for the caneberry

subgroup must be revised to specify a maximum of one soil application per season at 1.8 

lb ai/A and to reflect the following maximum seasonal rate: “Do not exceed the 

equivalent of 1.8 lb ai/A per crop of soil-applied and 0.2 lb ai/A per crop of foliar-applied 

mefenoxam-containing products for a maximum seasonal application rate of 2.0 lb ai/A.”

 To clarify the use pattern for established plantings specified in Part 2 of the labels for the 

4 lb ai/gal EC and SL formulations, the use directions should be revised to indicate that 

applications are to be directed toward the base of the plants.

 The proposed use directions for the 5% WP formulation must be revised to specify a 

maximum of two foliar applications per season at 0.1 lb ai/A/application and to reflect the 

following maximum seasonal rate: “Do not exceed the equivalent of 1.8 lb ai/A per crop 

of soil-applied and 0.2 lb ai/A per crop of foliar-applied mefenoxam-containing products 

for a maximum seasonal application rate of 2.0 lb ai/A.”

 For all three products, bromberre must be corrected to brombeere and nectaberry must be 

corrected to nectarberry.

 The proposed use directions for all three products must be amended to specify that no 

adjuvants may be added to spray mixtures for foliar use on caneberries.

Bushberries:

 The following berries are not members of bushberry subgroup 13-07B and must be 

removed from the crops listed under the bushberry subgroup on the labels for the 4 lb

ai/gal EC and SL formulations: bilberry, bearberry, cloudberry, muntries, and 

partridgeberry.

 To clarify the use pattern for established plantings specified in Part 2 of the labels for the 

4 lb ai/gal EC and SL formulations, the use directions should be revised to indicate that 

applications are to be directed toward the base of the plants.

 For both products, hostaberry must be corrected to jostaberry.

 When the proposed use on bushberries is registered for the 4 lb ai/gal EC and SL

formulations, the separate use directions for lingonberries may be removed from the 

labels.
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860.1550 Proposed Tolerances

 Based on the tolerance expressions recommended by the RARC and by HED in the 

metalaxyl/mefenoxam registration review, and to be consistent with Codex, the tolerance 

expression proposed by IR-4 under PP#9E7591 must be revised. The tolerance expression 

should be stated as follows:

Tolerances are established for residues of mefenoxam, including its 

metabolites and degradates, in or on the commodities in the table below. 

Compliance with the tolerance levels specified below is to be determined 

by measuring only metalaxyl [methyl N-(2,6-dimethylphenyl)-N-

(methoxyacetyl)-DL-alaninate].

 The proposed tolerances for snap bean and the caneberry subgroup are too high; tolerances 

should be established at 0.20 ppm for snap bean and 0.70 ppm for caneberry subgroup 13-

07A.

 The proposed tolerance for spinach is too low; a tolerance should be established at 10 ppm.

 In conjunction with establishment of the proposed tolerance for the bushberry subgroup, the 

mefenoxam tolerance for lingonberry can be removed.

 The proposed tolerance for the caneberry subgroup must be revised to reflect the correct 

commodity definition: “Caneberry subgroup 13-07A.”

HED recommends that conversion of conditional registration to unconditional registration 

for the requested uses on the caneberry subgroup may be considered upon submission of 

the following crop field trial data.

860.1500 Crop Field Trials

 To fulfill geographic distribution requirements, an additional field trial must be conducted 

in Zone 5 (raspberry) or 6 (blackberry). The required trial should include additional 

sampling intervals to assess residue decline. 
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 11 of 49

Background

The chemical structure and nomenclature of mefenoxam and its regulated metabolites/metabolite 

moieties are presented in Table 1. The physicochemical properties of the technical grade of 

mefenoxam are presented in Table 2. In addition, the chemical names and structures of 

metabolites referenced herein are presented in Appendix I. 

Table 1. Test Compound Nomenclature.

Compound

H3C

N

O

CH3

O

CH3 H3C

O

H3C

O

Common name mefenoxam; metalaxyl-M

Company experimental 

name

CGA-329351

IUPAC name methyl N-(methoxyacetyl)-N-(2,6-xylyl)-D-alaninate

CAS name methyl N-(2,6-dimethylphenyl)-N-(methoxyacetyl)-D-alaninate

CAS registry number 70630-17-0

End-use product (EP) Ridomil Gold® EC (4 lb ai/gal EC; EPA Reg. No. 100-801)

Ridomil Gold® Copper (5% WP; EPA Reg. No. 100-804)

Ridomil® Gold SL (4 lb ai/gal EC; EPA Reg. No. 100-1202)

Regulated metabolite in 

plant and rotational crop 

commodities

N

O

CH3

O

CH3

O O

H3C

HO

H C3

N-(2-hydroxymethyl-6-methylphenyl)-N-(methoxyacetyl)alanine methyl ester; 

CGA-94689

Regulated metabolite 

moiety in plant, livestock, 

and rotational crop 

commodities

H C3

N

CH3

R1 R2

2,6-dimethylaniline moiety (2,6-DMA when R1=R2=H)

Regulated metabolite 

moiety in livestock 

commodities

N

CH3

R1 R2

HO

2-hydroxymethyl-6-methylalanine (HMMA when R1=R2=H)
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 12 of 49

Table 2. Physicochemical Properties of Mefenoxam.

Parameter Value1 Reference

Boiling point/range >270 oC (PAI) MRID 43800301; 

DP# 223261, 4/24/96, L. 

Kutney

pH 5-6 at 25 °C (1% aqueous dispersion; TGAI)

Density 1.125 g/cm3 (20 °C; TGAI)

Water solubility 26 g/L (25 °C; PAI)

Solvent solubility Completely miscible in acetone, 

dichloromethane, ethyl acetate, methanol, noctanol, and toluene; 59 g/L in n-hexane at 25 

°C (TGAI).

Vapor pressure 3.3 x 10-3(25 °C; PAI)

Dissociation constant, pKa None in 1-10 pH range (PAI)

Octanol/water partition coefficient, 

Log(KOW)

1.71 at 25 °C (TGAI)

UV/visible absorption spectrum Not available

1

 TGAI = Technical grade of the active ingredient; PAI = Purified active ingredient.

860.1200 Directions for Use

IR-4 has submitted proposed amended use directions for three products registered to Syngenta: a 

4 lb ai/gal EC formulation, Ridomil Gold® EC (EPA Reg. No. 100-801; label dated 7/7/09); a 4 

lb ai/gal SL formulation, Ridomil Gold® SL (EPA Reg. No. 100-1202; label dated 7/30/09); and 

a 5% WP formulation, Ridomil Gold®/Copper (EPA Reg. No. 100-804; label dated 7/30/09). 

The 5% WP formulation is an MAI product containing 5% mefenoxam and 60% copper 

hydroxide. 

For the 4 lb ai/gal EC and SL formulations, the petitioner is proposing to: (1) expand the 

registered use on onions to include additional crops that are now included in the bulb vegetable 

crop group 3-07; (2) reduce the preharvest interval (PHI) for spinach from 21 to 3 days; (3) 

expand the registered foliar use of the 4 lb ai/gal EC and SL formulations on head and leaf 

lettuce to cover all members of the leafy vegetables group; and (4) add new uses on the caneberry

subgroup; and (5) expand the registered use on blueberries to cover the bushberry subgroup. For 

the 5% WP formulation, the petitioner is proposing to: (1) expand the registered use on onions 

to include additional crops that are now included in the bulb vegetable crop group 3-07; (2) 

reduce the PHI for spinach from 21 to 3 days; (3) add new uses on snap beans; and (4) add new 

uses on the caneberry subgroup. 

The proposed use directions for the EC and SL formulations are divided into two parts on the 

labels: “Part 1: Soil-Injected or Soil-Incorporated Applications” and “Part 2: Soil Directed and 

Other Foliar Applications.” 

The proposed changes to the crops or use patterns from those which appear on the accepted 

labels are highlighted in Table 3.
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

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Table 3. Summary of Directions for Use of Mefenoxam.

Applic. Timing, 

Type, and 

Equipment1

Formulation

[EPA Reg. 

No.]

Applic. 

Rate 

(lb ai/A)

Max. No. 

Applic. per 

Season

Max. Seasonal 

Applic. Rate

(lb ai/A)

PHI

(days)

Use Directions and 

Limitations2

Onions3: Dry Bulb including Garlic, Onions (dry bulb), Shallots (dry bulb); and Green including Green eschalots, 

Green onions, Green shallots, Japanese bunching onions, Leeks, Spring onions, Scallions. Including hybrids, 

cultivars, and varieties of these. Other Dry Bulb Crops: Great-headed Garlic, Serpent Garlic, Lily Bulb, Chinese 

Onion Bulb, Pearl Onion, Potato Onion Bulb. Other Green Bulb Crops: Chive (fresh leaves), Chinese Chive 

(fresh leaves), Hosta Elegans, Fritillaria (leaves), Kurrat, Lady’s Leek, Beltsville Bunching Onion, Onion (fresh), 

Macrostem Onion, Tree Tops Onion, Welsh Onion (tops), Shallot (fresh leaves)

Preplant 

incorporated 

(broadcast or 

band)

At planting

Soil spray 

(broadcast or 

band)

4 lb/gal EC

[100-801]

4 lb/gal SL

[100-1202]

0.25-0.50 Not 

specified

1.0 soil + 0.5 

foliar applied 

(dry bulb)

1.0 soil + 0.3 

foliar applied 

(green)

Not 

specified

Part 1: Apply in water or 

liquid fertilizer. For 

preplant incorporated 

application, mechanically 

incorporate in the top 2 

inches of soil. For 

banded applications, use a 

7-inch band.

Postemergence

Foliar

5% WP

[100-804] 0.1

4

(dry bulb 

and seed)

3

(green)

0.4

10

(dry 

bulb)

7

(green)

Begin applications when 

conditions are favorable 

for disease, but before 

infection; continue at a 

14-day RTI. Use of a 

suitable spreader-sticker 

is recommended.

Leafy Vegetables (Except Brassica): Celery, Endive (Escarole), Lettuce (Head and Leaf), Parsley, Rhubarb, 

Spinach, Swiss chard. Additional Leafy Vegetable Crops: Amaranth, Arugula, Cardoon, Celtuce, Chervil, 

Chinese Celery, Chrysanthemum (edible-leaved), Chrysanthemum (garland), Corn salad, Cress (garden), Cress 

(Upland), Dandelion, Dock (Sorrel), Florence Fennel (finochio), Orach, Purslane (garden), Purslane (winter), 

Radicchio (red chicory), Spinach (New Zealand), and Spinach (vine)

Preplant 

incorporated 

(broadcast or 

band)

At planting

Soil spray 

(broadcast or 

band) 

4 lb/gal EC

[100-801]

4 lb/gal SL

[100-1202]

0.50-1.0 Not 

specified

1.0 soil + 0.4 

foliar applied 

(all except 

spinach)

1.0 soil + 0.25 

shank to soil 

or 0.4 foliar 

applied 

(spinach)

7

(all 

except 

spinach)

3

(spinach)

Part 1: Apply in water or 

liquid fertilizer. For 

preplant incorporated 

application, mechanically 

incorporate in the top 2 

inches of soil. For 

banded applications, use a 

7-inch band. 

Postemergence

Foliar

4 lb/gal EC

[100-801]

4 lb/gal SL

[100-1202]

0.063-

0.125

Not 

specified

1.0 soil + 0.4 

foliar applied 

7

4

(all 

except 

spinach)

3

(spinach)

Part 2: Apply only in a 

tank mix with other 

fungicides, when 

conditions are favorable 

for disease; continue at a 

14-day RTI. 
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 14 of 49

Table 3. Summary of Directions for Use of Mefenoxam.

Applic. Timing, 

Type, and 

Equipment1

Formulation

[EPA Reg. 

No.]

Applic. 

Rate 

(lb ai/A)

Max. No. 

Applic. per 

Season

Max. Seasonal 

Applic. Rate

(lb ai/A)

PHI

(days)

Use Directions and 

Limitations2

Spinach only

Shank 

injections

Soil

4 lb/gal EC

[100-801]

4 lb/gal SL

[100-1202]

0.125 2

1.0 soil + 0.25 

shank to soil 

or 0.4 foliar 

applied

3

Part 1: Apply in addition 

to preplant incorporated 

or at-planting soil spray 

applications5, 21 days 

after planting or first 

cutting; a second 

application may be made 

after the next cutting at a 

21-day retreatment 

interval. 

Postemergence

Foliar

5% WP

[100-804] 0.125 2 Not specified 3

Apply 21 days after 

preplant or at-planting 

application of the 4 lb/gal 

EC formulation at 0.5-1 

lb ai/A or immediately 

after each repeated 

cutting. Make 1-2 

applications at a 14-day 

RTI; avoid late season 

applications.

Snap Beans

Postemergence

Foliar

5% WP

[100-804] 0.1 4 0.4 6

Begin applications at 

onset of disease; continue 

at a 7-day RTI.

Caneberry (Blackberry and Raspberry) Subgroup: Blackberry, Raspberry (Red and Black), Wild Raspberry 

Cultivars, Including hybrids, cultivars, and varieties of these.

Subgroup includes Andean Blackberry, Arctic Blackberry, Bingleberry, Black Satin Berry, Boysenberry, 

Bromberre, California Blackberry, Cherokee Blackberry, Chesterberry, Cheyenne Blackberry, Common 

Blackberry, Coryberry, Darrowberry, Dewberry, Dirksen Thornless Berry, Evergreen Blackberry, Himalayaberry, 

Hullberry, Lavacaberry, Loganberry, Lowberry, Lucretiaberry, Mammoth Blackberry, Marionberry, Mora, Mures 

Deronce, Nectaberry, Northern Dewberry, Olallieberry, Oregon Evergreen Berry, Phenomenalberry, Rangeberry, 

Ravenberry, Rossberry, Shawnee Blackberry, Southern Dewberry, Tayberry, Youngberry, Zarzamora

At planting

Soil spray 

(broadcast or 

band)

4 lb/gal EC

[100-801]

4 lb/gal SL

[100-1202]

1.8 1

(implied)

3.6

soil applied 45

Part 1: New plantings: 

For banded applications, 

use an 18-inch band

Postemergence

Soil spray 

(band)

1.8 Not 

specified

Part 2: Established 

plantings: Apply in a 3-ft 

band over the row before 

plants start to grow in the 

spring.

Postemergence

Foliar

5% WP

[100-804] 0.1 4

3.6 soil + 

foliar applied 0

Begin applications when 

conditions are favorable 

for disease, but before 

infection; continue at a 7-

day RTI.
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 15 of 49

Table 3. Summary of Directions for Use of Mefenoxam.

Applic. Timing, 

Type, and 

Equipment1

Formulation

[EPA Reg. 

No.]

Applic. 

Rate 

(lb ai/A)

Max. No. 

Applic. per 

Season

Max. Seasonal 

Applic. Rate

(lb ai/A)

PHI

(days)

Use Directions and 

Limitations2

Bushberry Subgroup: Blueberries (High and Low Bush), Currants, Elderberry, Gooseberry, Highbush Cranberry, 

Including hybrids, cultivars, and varieties of these.

Other Bushberries in Subgroup: Aronia Berry, Highbush Blueberry, Lowbush Blueberry, Bearberry, Bilberry, 

Buffalo Currant, Chilean Guava, Cloudberry, Black Currant, Red Currant, Elderberry, European Barberry, 

Gooseberry, Highbush Cranberry, Edible Honeysuckle, Huckleberry, Hostaberry, Juneberry, Lingonberry, 

Muntries, Native Currant, Partridgeberry, Salal, Sea Buckthorn.

At planting

Soil spray 

(broadcast or 

band)

4 lb/gal EC

[100-801]

4 lb/gal SL

[100-1202]

1.8 1

(implied)

3.6

soil applied 0

Part 1: Application is to 

be made to new plantings. 

For banded applications, 

use an 18-inch band.

Post-planting

Soil spray 

(band)

1.8 1

Part 2: New plantings: 

After initial at-planting 

application, reapply once 

during a period favorable 

for root rot.

Postemergence

Soil spray 

(band)

1.8 2

Part 2: Established 

plantings: Apply in a 3-ft 

band over the row before 

plants start to grow in the 

spring. Re-apply once 

during the period most 

favorable for root rot.

1

 Information pertaining to equipment type appears on the accepted labels; use of ground, aerial, and irrigation 

equipment is approved for all products. Ground applications are to be made in ≥20 gal/A of water, and aerial 

applications are to be made in ≥3 gal/A of water.

2

 For the proposed and registered labels for the 4 lb/gal EC and SL formulations, Part 1 = Soil-Injected or SoilIncorporated Applications and Part 2 = Soil Directed and Other Foliar Applications. RTI = Retreatment interval.

3

 The proposed and accepted labels for the 5% WP formulation also list onions grown for seed. 

4

 For the 4 lb/gal SL formulation, Section B reflects foliar use on all leafy vegetables listed; on the Data Package 

Label, the proposed use is listed for head and leaf lettuce and spinach. The registered labels for both products reflect 

foliar use on head and leaf lettuce only.

5

 This statement appears on the 4 lb/gal EC label only; use directions for the 4 lb/gal SL state: Shank in 21 days 

after planting or after the first cutting.
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 16 of 49

The accepted labels include the following rotational crop restrictions: (1) 0 days for crops for 

which use of mefenoxam/metalaxyl is registered; (2) 40 days (5% WP formulation) and 14 days 

(4 lb ai/gal EC and SL formulations) for cereal grains other than corn; (3) 9 months for corn; and 

(4) 12 months for any crop for which use of mefenoxam/metalaxyl is not registered. The 

directions on the 5% WP label further state that deciduous fruit and nut crops and other perennial 

crops may be planted immediately following last application of mefenoxam provided they will 

not bear harvestable fruit within 12 months.

HED notes that the cover letters accompanying the accepted labels for the 4 lb ai/gal EC and SL

formulations and the 5% WP formulation require that the following statement be added: 

“Maximum usage when applying both metalaxyl and mefenoxam containing products to the 

same crop within the same season: Do not apply more than the maximum seasonal total for the 

active ingredient as stated on the label of the product containing the lowest seasonal total on that 

crop.”

Conclusions. The submitted use directions are sufficient to allow evaluation of the submitted 

and available residue data relative to the proposed use patterns and crops. The submitted and 

available data for mefenoxam and metalaxyl will support the requested uses of mefenoxam on 

onions (and other green and dry bulb crops), snap beans, spinach, and the caneberry and 

bushberry subgroups, pending revision of the proposed labels as indicated below.

HED notes that as stated in OPPTS 860.1500, data may be translated among the SL and EC 

formulation classes and other formulation types which are diluted in water prior to application 

for applications directed to the soil (as opposed to foliar treatments).

Onions: Previously reviewed crop field trial data for metalaxyl on bulb onions and green onions

will support the proposed expanded use on the onions listed in Table 3, provided the following 

changes to the use directions are made:

 The proposed use directions for the 4 lb ai/gal EC and SL formulations should be 

revised to reflect the following maximum seasonal rate for bulb onion: “Do not exceed 

the equivalent of 1.0 lb ai/A per crop of soil-applied and 0.4 lb ai/A per crop of foliarapplied mefenoxam-containing products.”

 The proposed use directions for the 5% WP formulation should be revised to reflect the 

following maximum seasonal rates: (1) for bulb onion, “Do not exceed the equivalent 

of 1.0 lb ai/A per crop of soil-applied and 0.4 lb ai/A per crop of foliar-applied 

mefenoxam-containing products”; and (2) for green onion, “Do not exceed the 

equivalent of 1.0 lb ai/A per crop of soil-applied and 0.3 lb ai/A per crop of foliarapplied mefenoxam-containing products.”

HED notes that the expanded list of onions that appears on each label could additionally include 

the bulb onions daylily bulb and fritillaria bulb, and the green onion wild leek.

Leafy vegetables/spinach: Revisions are needed to the proposed labels as follow.

 The proposed labels for Leafy Vegetables and Spinach Only must be revised. The 3-day

PHI for spinach can be applied only to application types and rates supported by the 3-day

PHI data. The submitted spinach crop field trial data reflect a single at-planting 
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 17 of 49

application of the 4 lb ai/gal EC formulation at 1.0 lb ai/A followed by two foliar 

applications of the 5% WP formulation at 0.125 lb ai/A/application for a total seasonal 

application rate of 1.25 lb ai/A. Soil application of the EC formulation can be translated 

to the SL formulation. Based on the available data for spinach at the proposed 3-day PHI, 

the proposed use directions for Spinach Only should be revised to specify soil surface 

application of the EC or SL formulations and foliar directed or broadcast spray

applications of the WP formulation, and to specify the following maximum seasonal 

rates: “Do not exceed the equivalent of 1.0 lb ai/A per crop of soil-applied mefenoxam 

containing products at planting and 0.25 lb ai/A of foliar-applied mefenoxam containing 

products.” The proposed changes to the existing Leafy Vegetables section of the existing 

labels to establish a 3-day PHI for spinach should be removed.

 The available and submitted crop field trial data for leafy vegetables do not support 

expanding the registered foliar uses of the 4 lb ai/gal EC and SL formulations on head 

and leaf lettuce to include spinach or any other members of the leafy vegetables except 

Brassica crop group. For the 4 lb ai/gal EC and SL formulations, spinach and all other 

members of the leafy vegetables except Brassica crop group, except head and leaf lettuce, 

must be removed from the use directions for Part 2 of the proposed label; the reference to 

Part 2 of the label that appears in Part 1 should be revised accordingly. 

 On the 5% WP formulation label, the statement referring to a 21-day PHI for spinach 

should be removed.

 No spray adjuvants were used in the submitted crop field trials on spinach. HED has 

concluded that spray adjuvant use must be prohibited on product labels when the field 

trials did not include adjuvants (see minutes of 4/16/08 ChemSAC meeting). Therefore, 

the product label for foliar applications must be amended to specify that no adjuvants may

be added to spray mixtures for foliar use on spinach.

 When HED approved the registered use of the 4 lb ai/gal EC formulation on head and leaf 

lettuce (DP# 324493, 3/17/06, L. Cheng), certain label revisions were required which 

have not been made. These revisions also apply to the label for the 4 lb ai/gal SL

formulation. As previously required under DP# 324493, Part 1 of the labels for the 4 lb

ai/gal EC and SL formulations should be revised to specify that no more than one soildirected application may be made, and Part 2 should be revised to specify a maximum of 

4 foliar-directed applications.

Snap Beans: The submitted crop field trial data for snap bean do not reflect the maximum 

proposed seasonal rate for snap bean. The submitted snap bean crop field trial data reflect a 

single at-planting application of the 4 lb ai/gal EC formulation at 0.5 lb ai/A followed by two 

foliar applications of the 5% WP formulation at 0.1 lb ai/A/application for a total seasonal 

application rate of 0.70 lb ai/A. The data may be used to support foliar use of the 5% WP on 

snap bean provided the proposed use directions are amended as specified below.

 The proposed use directions for the 5% WP formulation must be revised to specify a 

maximum of two applications per season at 0.1 lb ai/A/application and to reflect the 

following maximum seasonal rate for snap bean: “Do not exceed the equivalent of 0.5 lb 

ai/A per crop of soil-applied mefenoxam containing products at planting and 0.2 lb ai/A 

per crop of foliar-applied mefenoxam-containing products.”
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 18 of 49

 The proposed use directions for the 5% WP formulation must be revised to propose a 7-

day preharvest interval (PHI). Four of eight field trials have a 7-day PHI and four have a 

6-day PHI.

 No spray adjuvants were used in the submitted crop field trials on snap bean. Therefore, 

the product label for foliar applications must be amended to specify that no adjuvants may

be added to spray mixtures for foliar use on snap bean.

If the petitioner wishes to support the proposed use pattern of a maximum of four foliar 

applications to snap beans at 0.1 lb ai/A/application following soil application at 0.5 lb ai/A, crop 

field trial data reflecting that use pattern must be submitted.

Caneberries: The submitted crop field trial data for blackberries and raspberries do not reflect 

the maximum proposed seasonal rate for caneberries. The submitted caneberry field trial data 

reflect two foliar applications of the 5% WP formulation at 0.1 lb ai/A/ application following a 

single at-planting application of the 4 lb ai/gal EC formulation at 1.8 lb ai/A for a total seasonal 

application rate of 2.0 lb ai/A. The data may be used to support foliar use of the 5% WP on 

caneberries provided the proposed use directions are amended as specified below.

 

 The proposed use directions for the 4 lb ai/gal EC and SL formulations for the caneberry

subgroup must be revised to specify a maximum of one soil application per season at 1.8 

lb ai/A and to reflect the following maximum seasonal rate: “Do not exceed the 

equivalent of 1.8 lb ai/A per crop of soil-applied and 0.2 lb ai/A per crop of foliar-applied 

mefenoxam-containing products for a maximum seasonal application rate of 2.0 lb ai/A.”

 To clarify the use pattern for established plantings specified in Part 2 of the labels for the 

4 lb ai/gal EC and SL formulations, the use directions should be revised to indicate that 

applications are to be directed toward the base of the plants.

 The proposed use directions for the 5% WP formulation must be revised to specify a 

maximum of two foliar applications per season at 0.1 lb ai/A/application and to reflect the 

following maximum seasonal rate: “Do not exceed the equivalent of 1.8 lb ai/A per crop 

of soil-applied and 0.2 lb ai/A per crop of foliar-applied mefenoxam-containing products 

for a maximum seasonal application rate of 2.0 lb ai/A.”

 For all three products, bromberre must be corrected to brombeere and nectaberry must be 

corrected to nectarberry. 

 No spray adjuvants were used in the submitted crop field trials on caneberries. Therefore, 

the product label for foliar applications for all three products must be amended to specify

that no adjuvants may be added to spray mixtures for foliar use on caneberries.

If the petitioner wishes to support the proposed maximum seasonal rate of 3.6 lb ai/A for soil and 

foliar applications to caneberries, crop field trial data reflecting that use pattern must be 

submitted.

HED notes that the accepted labels for the 4 lb ai/gal EC and SL formulations include use 

directions for raspberries reflecting postemergence use at 0.125 lb ai/A/application in the spring 

and in the fall after harvest with a 45-day PHI. This use is supported by the established tolerance 

for metalaxyl residues in/on raspberries at 0.5 ppm.
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 19 of 49

Bushberries: Previously reviewed crop field trial data for metalaxyl on blueberry will support the 

proposed expanded use of the 4 lb ai/gal EC and SL formulations on the bushberries listed in 

Table 3, except as noted below. The accepted labels for the 4 lb ai/gal EC and SL formulations 

include separate use directions for lingonberries that are similar to the registered use on 

blueberries. The following changes to the use directions are recommended.

 The following berries are not members of the bushberry subgroup 13-07B and must be 

removed from the crops listed under the bushberry subgroup: bilberry, bearberry, 

cloudberry, muntries, and partridgeberry.

 To clarify the use pattern for established plantings specified in Part 2 of the labels for the 

4 lb ai/gal EC and SL formulations, the use directions should be revised to indicate that 

applications are to be directed toward the base of the plants.

 For both products, hostaberry must be corrected to jostaberry.

 When the proposed use on bushberries is registered for the 4 lb ai/gal EC and SL

formulations, the separate use directions for lingonberries may be removed from the 

labels.

Bilberry, bearberry, cloudberry, muntries, and partridgeberry are members of crop subgroup 13-

07G (lowgrowing berry) or 13-07H (lowgrowing berry subgroup, except strawberry). To support 

the proposed use patterns for the 4 lb ai/gal EC and SL on these berries, additional crop field trial 

data would be required reflecting application to the representative commodities of strawberry (for 

subgroup 13-07G) or cranberry (for subgroup 13-07H). Although the accepted labels for the 4 lb

ai/gal EC and SL formulations include use directions for cranberry and strawberry, the use 

directions are more restrictive than the proposed use pattern for bushberries: maximum seasonal 

rate of 2.65 lb ai/A and 45-day PHI for cranberry, and maximum seasonal rate of 1.5 lb ai/A for 

strawberry.

860.1300 Nature of the Residue - Plants

Residue Chemistry Memo No DP#, 2/14/07, W. Britton (RARC Report)

Residue Chemistry Memo DP# 269910, 10/27/00, N. Dodd, A. Lowit, and M. Bonner (MARC Decision)

Residue Chemistry Memo DP# 268454, 10/17/00, N. Dodd, A. Lowit, and M. Bonner (Issues to be presented to 

MARC)

The nature of the residue in plants is adequately understood for mefenoxam, based on metalaxyl 

metabolism studies on potato, grape, and lettuce. The data indicate that metalaxyl is taken up, 

translocated, and extensively metabolized by plants. Metabolism involves oxidation of a ringmethyl group to the alcohol and then the carboxylic acid, hydroxylation of the phenyl group, 

hydrolysis of the methyl ester and methyl ether bonds, and N-dealkylation. 

Metabolites can be separated into four classes: (1) those containing a 2,6-DMA moiety; (2) those 

containing an HMMA moiety; (3) those containing a Ring-OH moiety; and (4) those containing a 

benzoic acid moiety.

HED originally concluded that the mefenoxam residues to be regulated for the tolerance 

expression and for dietary assessments would be (R)- and (S)-2-[(2,6-dimethylphenyl)-

methoxyacetylamino]-propionic acid methyl ester, its metabolites containing the 2,6-DMA 

moiety, and CGA-94689, each expressed as mefenoxam equivalents.
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 20 of 49

The HED Risk Assessment Review Committee (RARC) subsequently determined (report dated 

2/14/07) that: (1) the residue to be regulated (in the tolerance expression) in plant and livestock 

commodities is (R)- and (S)-2-[(2,6-dimethylphenyl)-methoxyacetylamino]-propionic acid 

methyl ester; (2) the current/reassessed tolerance levels should be retained; (3) for risk 

assessment, the residues of concern in plant and livestock commodities are 

metalaxyl/mefenoxam, its metabolites containing the 2,6-DMA moiety, its metabolites 

containing the HMMA moiety, its metabolites containing the Ring-OH moiety, and its 

metabolites containing the benzoic acid moiety; and (4) the available residue chemistry data can 

be used and factors may be employed to estimate the total residues of concern in dietary risk 

assessments.

In connection with registration review of mefenoxam (DP#368461, N. Dodd, 4/13/10), HED 

recommended for modification of the tolerance expression for mefenoxam (40 CFR §180.546) 

according to the new compliance/measurement policy (Interim Guidance on Tolerance 

Expressions, Steve Knizner, May 27, 2009) as follows:

Tolerances are established for residues of mefenoxam, including its metabolites 

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

tolerance levels specified below is to be determined by measuring only metalaxyl 

[methyl N-(2,6-dimethylphenyl)-N-(methoxyacetyl)-DL-alaninate].

860.1300 Nature of the Residue - Livestock

There are no livestock feedstuffs associated with the proposed uses on bulb vegetables, spinach, 

snap beans/edible-podded beans, caneberries, and bushberries. Therefore, data requirements for 

livestock metabolism are not relevant to this tolerance petition.

860.1340 Residue Analytical Methods

Residue Chemistry Memo DP# 333767, 3/7/07, B. Cropp-Kohlligian

Residue Chemistry Memo No DP#, 2/14/07, W. Britton (RARC Report)

Residue Chemistry Memo DP# 274194, 4/20/01, N. Dodd

Residue Chemistry Memo DP# 269910, 10/27/00, N. Dodd, A. Lowit, and M. Bonner (MARC Decision)

Residue Chemistry Memo DP# 268454, 10/17/00, N. Dodd, A. Lowit, and M. Bonner (Issues to be presented to 

MARC)

The residue analytical methods available for enforcement of tolerances in crop commodities are 

common moiety methods which determine residues of metalaxyl/mefenoxam and metabolites 

that are convertible to 2,6-DMA. These methods include: (1) Method I in PAM, Vol. II (Method 

AG-348) which determines residues in plant commodities using GLC/AFID; and (2) Method 

AG-395 (sent to FDA for inclusion in PAM, Vol. II as Method III), an improved version of 

Method AG-348, which determines residues in plant commodities using GLC/NPD. 

Neither Method AG-348 nor Method AG-395 distinguish between the R- and S-enantiomers of 

metalaxyl/mefenoxam; however, a chiral LC/MS method, Method 456-98, for the 

enantioselective determination of the D- and L-enantiomers of metalaxyl in crops has been 

adequately validated by ACB/BEAD, and a revised version of the method has been submitted for 

inclusion in PAM, Vol. II. 
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

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HED has determined that the 2,6-DMA common moiety residue analytical methods available for 

tolerance enforcement and used for data collection will not adequately recover all of the 

metalaxyl/mefenoxam residues of concern in the current tolerance expressions. While these 

methods are adequate to recover residues of metalaxyl/mefenoxam per se, they will not 

adequately recover metabolites containing the HMMA moiety and may not adequately recover all 

metabolites containing the 2,6-DMA moiety with the certainty needed to set legal limits, nor are 

they likely to recover metabolites containing the Ring-OH moiety or the benzoic acid moiety. As 

a result, in addition to the changes to the tolerance expression and the residues of concern for risk 

assessment addressed above, the HED RARC determined that: 1) the multiresidue method PAM, 

Vol. I Section 302 (Protocol D), which completely recovers metalaxyl/mefenoxam per se (>80% 

according to FDA PESTDATA) is an adequate enforcement method for the determination of 

metalaxyl/mefenoxam per se in plant and livestock commodities; and (2) all future 

metalaxyl/mefenoxam magnitude of the residue data should include (a) analysis for residues of 

parent only using the multiresidue method PAM, Vol. I Section 302 (Protocol D) in order to 

establish more appropriate tolerance levels; and (b) analysis with a 2,6-DMA common moiety

method and recovery data for parent, CGA-62826, and CGA-94689 in order to refine dietary risk 

assessments.

Data collection methods: Samples of snap bean and caneberries from the crop field trial studies 

included in this petition were analyzed for residues of mefenoxam per se using Method 456-98 

with minor modifications. Samples of spinach, and selected samples of snap bean and 

caneberries were analyzed for combined residues of mefenoxam, metalaxyl, and metabolites 

convertible to 2,6-DMA using a GC/MS method, defined by working method numbers YARL0601A (caneberry), -0601C (snap bean), and -0601D (spinach) which was derived, with minor 

modifications, from Method AG-395. The modifications included minor changes in equipment 

and glassware, modification of the solid-phase extraction (SPE) clean-up procedure to remove 

the use of trifluoroacetic acid for derivatization, and MS instead of NPD. 

For Method 456-98, samples were extracted with methanol:water (80:20, v:v) at reflux, then 

filtered and applied to a C18 SPE cartridge to remove co-extractives. The purified extract was 

reduced to aqueous, acidified with 0.10 N HCl, diluted with water, and partitioned with 

dichloromethane (DCM). The DCM phase was cleaned up on a silica SPE cartridge, using ethyl 

acetate in hexane (40% v:v) to elute residues. The extract was evaporated to dryness, 

reconstituted in mobile phase, and filtered for analysis by chiral reverse-phase LC/MS. The 

LLMV was 0.05 ppm for snap bean and caneberries.

For Method YARL-0601A, C, and D, samples were extracted with methanol:water (80:20, v:v) 

at reflux, then filtered. An aliquot was reduced to dryness, redissolved in water, and combined 

with methanesulfonic acid, then refluxed to produce 2,6-DMA. Water, hexane, and 25% NaOH 

were added, and the mixture was subjected to reflux/steam distillation. The resulting hexane 

phase was collected and applied to a silica SPE cartridge, using DCM to elute residues. The 

DCM phase was reduced to near dryness and reconstituted in DCM for analysis by GC/MS. 

Residues were converted to mefenoxam equivalents using a molecular weight conversion factor 

of 2.305. The LLMVs were 0.1 ppm for spinach and 0.05 ppm for snap bean and caneberries.
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

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The data collection methods were adequate for data collection based on acceptable method 

validation and concurrent recovery data. Fortification levels were adequate to bracket residues 

found in treated samples. 

Conclusions. The available and submitted residue analytical methods data are adequate to 

satisfy data requirements for this petition. Adequate methodology is available for tolerance 

enforcement purposes for the residue of concern in crop commodities, mefenoxam per se, as 

determined by the RARC. These methods include Method 456-98 and PAM multiresidue 

method Protocol D. Samples of crop commodities from the submitted crop field trials were 

analyzed for residues of mefenoxam per se and for combined residues of mefenoxam, metalaxyl, 

and metabolites convertible to 2,6-DMA using adequate data collection methods. 

HED notes that although samples from the submitted crop field trials were analyzed using a 2,6-

DMA common moiety method, recovery data were provided for parent only; no recovery data 

were provided for metabolites CGA-62826, and CGA-94689 as required in the RARC decision 

to refine dietary risk assessments.

HED notes that the method used for determination of residues of mefenoxam per se in snap 

beans and caneberries did not include determination of the L-enantiomer, which is included in 

the tolerance expression. However, the ratio of D-enantiomer to L-enantiomer in mefenoxam 

products is >90% (DP# 223261, 4/24/94, L. Kutney). Therefore, the lack of analysis for the Lenantiomer would not significantly affect the residue results for snap bean and caneberry. The 

petitioner should note for future submissions that the tolerance expression for mefenoxam 

includes the L-enantiomer, and therefore, as stated above, analytical methods should include 

determination of both the D- and L-enantiomers. 

860.1360 Multiresidue Methods

Residue Chemistry Memo No DP#, 2/14/07, W. Britton (RARC Report)

Residue Chemistry Memo DP# 268454, 10/17/00, N. Dodd, A. Lowit, and M. Bonner (Issues to be presented to 

MARC)

The FDA PESTDATA database (dated 06/05) indicates that metalaxyl is completely recovered 

(>80%) using the multiresidue method in PAM, Vol. I, Section 302 (Protocol D), but is not 

recovered using Sections 303 and 304 (Protocols E and F). In addition, metabolite CGA-100255 

was found to have small, variable recovery (37-146%) using Section 302. Metabolite CGA37734 was completely recovered using Section 302 but was not recovered using Sections 303 

and 304. Metabolites CGA-94689A and 94689B had small, variable recovery (39-108%) using 

Section 302 but were not recovered using Sections 303 and 304. Metabolite CGA-62826 was not

recovered through any of the protocols. 

The HED RARC previously determined that the multiresidue method PAM, Vol. I Section 302 

(Protocol D), which completely recovers metalaxyl/mefenoxam per se (>80% according to FDA 

PESTDATA) is an adequate enforcement method for the determination of metalaxyl/mefenoxam 

per se in plant and livestock commodities.
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

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860.1380 Storage Stability

Residue Chemistry Memo DP#223261, 4/23/96, L. Kutney

Storage stability data are available for metalaxyl indicating that weathered residues of metalaxyl 

and metabolites are stable in spinach stored frozen (-20 oC) for up to 39 months (MRID 

43446901, DP# 223261, L. Kutney, 4/23/96).

Concurrent storage stability studies were conducted to support the storage intervals and 

conditions of samples from the submitted snap bean and caneberry field trials; samples were 

fortified with mefenoxam per se. The data demonstrate that for samples analyzed for residues of 

mefenoxam per se, residues were stable during frozen storage for up to 609 days (20.0 months) 

for snap bean and 296 days (9.7 months) for caneberry, and that for samples analyzed for 

combined residues of mefenoxam/metalaxyl and metabolites convertible to 2,6-DMA, residues

were stable for up to 1716 days (56.4 months) for snap bean and 1360 days (44.7 months) for 

caneberry. No 0-day data were provided in the concurrent storage stability studies; storage 

stability studies should always include a 0-day sampling interval to establish the residue levels 

present at the time samples are placed into storage [see OPPTS 860.1380(d)(6)(i)].

The storage intervals and conditions of samples from the field trials submitted in association with 

the subject petition are presented in Table 4. 

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

Matrix Storage 

Temperature 

(°C)

Actual Storage 

Duration (months)

Interval of Demonstrated 

Storage Stability (months)

Spinach ≤-12 909-1168 days 

(29.9-38.4 months)

Adequate storage stability data are available 

demonstrating that combined residues of 

metalaxyl and metabolites are stable for up to 39 

months in/on spinach.

Snap Bean

(Original analysis:

Method 456-98)

≤-12 479-655 days 

(15.8-21.5 months)

Concurrent storage stability data indicate that 

residues of mefenoxam per se are stable for up to 

609 days (20 months).

Snap Bean

(Reanalysis:

Method YARL-0601C)

≤-12 1573-1595 days 

(51.7-52.5 months)

Concurrent storage stability data indicate that 

residues of mefenoxam per se, determined as 

combined residues of metalaxyl, mefenoxam, 

and metabolites convertible to 2,6-DMA, are 

stable for up to 1716 (56 months).

Caneberries

(Original analysis:

Method 456-98)

≤-12 133-182 days 

(4.4-6.0 months)

Concurrent storage stability data indicate that 

residues of mefenoxam per se are stable for up to 

296 days (9.7 months).

Caneberries

(Reanalysis:

Method YARL-0601A)

≤-12 1387-1402 days 

(45.6-46.1 months)

Concurrent storage stability data indicate that 

residues of mefenoxam per se, determined as 

combined residues of metalaxyl, mefenoxam, 

and metabolites convertible to 2,6-DMA, are 

stable for up to 1360 days (44.7 months).

Conclusions. The available storage stability data for spinach and the submitted concurrent 

storage stability data for snap beans and caneberries are adequate to support the submitted crop 
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

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field trials. The data indicate that there are no storage stability issues, and no corrections for 

decline on storage are needed. 

860.1400 Water, Fish, and Irrigated Crops

This guideline topic is not relevant to the proposed uses.

860.1460 Food Handling

This guideline topic is not relevant to the proposed uses.

860.1480 Meat, Milk, Poultry, and Eggs

There are no livestock feedstuffs associated with the proposed uses on bulb vegetables, spinach, 

snap beans/edible-podded beans, caneberries, and bushberries. Therefore, data requirements 

pertaining to meat, milk, poultry, and eggs are not relevant to this tolerance petition.

860.1500 Crop Field Trials

DER References: 47803101.der.doc (Snap bean; includes review of MRID 47803102)

47803103.der.doc (Caneberries; includes review of MRID 47803104)

47803105.der.doc (Spinach)

Residue Chemistry Memo DP# 223261, 4/24/96, L. Kutney

Residue Chemistry RED Chapter, DP# 197037, 6/16/94, S. Hummel

HED has concluded (DP# 223261) that the established tolerances for metalaxyl will be adequate 

to support the use of mefenoxam on the same crops provided that (1) the use rates for 

mefenoxam are one-half the rate of metalaxyl; (2) mefenoxam applications are made in the same 

way as for metalaxyl; and (3) the labels restrict the use of both pesticides concurrently on the 

same crop. 

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

IR-4 is proposing to expand the registered use of mefenoxam on bulb and green onions to 

support the new bulb onion subgroup 3-07A and the green onion subgroup 3-07B. Bulb onion is 

the representative commodity of the bulb onion subgroup, and green onion is the representative 

commodity of the green onion subgroup.

No residue data were provided in support of the proposed expanded use. The registered use of 

mefenoxam on bulb and green onions is supported by crop field trial data for metalaxyl on these 

crops, reflecting a variety of use patterns, which were summarized in the Metalaxyl Registration 

Standard dated 6/22/87. For bulb onion, the use patterns tested included preemergence soil 

application of an EC formulation at 2 lb ai/A followed by five foliar applications of a WP 

formulation at 0.2 lb ai/A/application for a maximum seasonal rate of 3.0 lb ai/A; PHIs ranged 7-

34 days. For green onion, the use patterns tested included preemergence soil application of an 

EC formulation at 2 lb ai/A followed by three or four foliar applications of a WP formulation at 

0.2 lb ai/A/application for maximum seasonal rates of 2.6 or 2.8 lb ai/A; PHIs ranged 7-14 days. 

The available data were re-assessed for the Residue Chemistry Chapter of the Metalaxyl RED 
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

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where it was concluded that no additional data were needed for dry bulb or green onion. 

Tolerances of 3.0 and 10.0 ppm are established for metalaxyl on bulb and green onion, 

respectively. As specified in DP# 223261, the use rates for mefenoxam are one-half the rate of 

metalaxyl, and mefenoxam applications are made in the same way as for metalaxyl; therefore, the 

data for metalaxyl are adequate to support the proposed use of mefenoxam.

Conclusions. The proposed/registered use of mefenoxam on bulb and green onion is supported 

by adequate crop field trial data for metalaxyl. Minor revisions to the EC, SL, and WP labels 

must be made as requested under Section 860.1200. Because bulb onion is the representative 

commodity of the bulb onion subgroup, and green onion is the representative commodity of the 

green onion subgroup, HED has no objections to expanding the registered use to cover the 

members of the crop subgroups.

The available data for bulb and green onion will support tolerances of 3.0 ppm for onion, bulb 

subgroup 3-07A, and 10 ppm for the onion, green, subgroup 3-07B, respectively.

Spinach

Under PP#9E7591, IR-4 is proposing to reduce the established PHI for use of mefenoxam on 

spinach from 21 days to 3 days. In conjunction with this request, IR-4 has submitted revised use 

directions for the 4 lb ai/gal EC and the SL formulations indicating that they wish to expand the 

registered foliar uses on head and leaf lettuce for one or both products to include all members of 

the leafy vegetables crop group. 

In support of the reduced PHI for spinach, IR-4 submitted field trial data for mefenoxam on 

spinach. Nine spinach field trials were conducted in Zones 1 (NY; 1 trial), 2 (MD and NJ; 3 

trials), 6 (TX; 2 trials), 8 (CO; 1 trial), and 10 (CA; 2 trials) during 2004. 

At each test site, one untreated and one treated plot were established. Each treated plot received 

an initial soil surface spray application of a 4 lb ai/gal EC formulation made at planting at ~1.0 lb 

ai/A. Seed was planted immediately before or following application on the same day, except at 

the two CA sites and the CO and NJ sites, where seed was planted the day before application. 

The at-planting application was followed by two foliar directed or broadcast spray applications of 

a 5% WP formulation made at ~0.125 lb ai/A/application, for a total seasonal rate of ~1.25 lb 

ai/A (1x the maximum proposed seasonal application rate for this formulation on spinach). The 

first foliar application was made 25-60 days after the soil application, and the second foliar 

application was made 12-15 days after the first foliar application. All applications were made 

using ground equipment in spray volumes of 29-64 gal/A; no adjuvants were used. Samples of 

mature spinach leaves were collected 2-4 days following the final application. 

Samples were analyzed using an adequate GC/MS method that determines combined residues of 

mefenoxam, metalaxyl, and metabolites convertible to the 2,6-DMA moiety as 2,6-DMA. The 

LLMV was 0.10 ppm. Sample storage intervals and conditions are reported in Table 4. 

Adequate storage stability data are available to support the crop field trials.

The results of the spinach field trials are presented in Table 5. Following one at-planting soil 

application of the 4 lb ai/gal EC formulation at 0.97-1.0 lb ai/A and two broadcast foliar 
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applications of the 5% WP at 0.122-0.127 lb ai/A/application for total application rates of 1.21-

1.25 lb ai/A, combined residues of mefenoxam/metalaxyl and metabolites determined as 2,6-

DMA were 1.47-6.19 ppm in/on spinach leaves harvested 2-4 days after application.

A residue decline trial was not included in the study.

Table 5. Summary of Residue Data from Field Trials with Mefenoxam.

Crop matrix Total Applic. 

Rate (lb ai/A)

PHI 

(days)

Residue Levels (ppm)1

n Min. Max. HAFT 2 Median Mean Std. Dev.

SPINACH (proposed use for 5% WP = 1.0 lb ai/A soil + 0.25 lb ai/A foliar for 1.25 lb ai/A total application 

rate; 3-day PHI; proposed use for 4 lb ai/gal EC and SL = 1.0 lb ai/A soil + 0.4 lb ai/A foliar for 1.4 lb ai/A 

total application rate; 3-day PHI)

Spinach 

leaves 

1.21-1.25 2-4 18 1.47 6.19 5.85 3.07 3.26 1.34

1

 Combined residues of mefenoxam, metalaxyl, and metabolites convertible to 2,6-DMA.

2

 HAFT = Highest Average Field Trial.

The representative crops for the leafy vegetables (except Brassica vegetables) crop group are 

celery, head lettuce, leaf lettuce, and spinach. 

Conclusions. The submitted field trial residue data for spinach are adequate to support a 

reduction in PHI to 3 days for spinach treated with a soil application of the EC or SL formulation 

followed by foliar application of the WP formulation. The submitted crop field trial data will 

support a reduction in PHI for spinach treated with this combination of products only. 

Additional field trial data reflecting foliar application of EC and SL formulations to spinach with 

a 3-day PHI would be required to support a reduction in PHI for the proposed foliar uses of the 4 

lb ai/gal EC and SL formulations on spinach. Based on current Agency policy, data for the WP 

formulation cannot support EC or SL foliar applications with short PHIs, and EC data cannot be 

translated to SL for foliar applications with short PHIs. The reviewer could not find any data for 

metalaxyl/mefenoxam supporting foliar application of an SL formulation on leafy vegetables.

In the absence of supporting crop field trial data, HED recommends against expanding the 

registered foliar uses of the 4 lb ai/gal EC and SL formulations on head and leaf lettuce to 

include spinach or any other members of the leafy vegetables (except Brassica vegetables) crop 

group. To expand the registered foliar uses of the 4 lb ai/gal EC and SL formulations on head 

and leaf lettuce to include all members of the leafy vegetables (except Brassica vegetables) crop 

group, data reflecting foliar uses of the EC and SL formulations on spinach and celery reflecting 

the proposed use rate and PHI must be submitted or referenced. If spinach is to have a 3-day PHI

while the others in the crop group have a 7-day PHI, spinach would have to be excluded from the 

crop group tolerance and have its own tolerance.

The number and location of field trials are in accordance with OPPTS Guideline 860.1500 for 

spinach. HED notes that one trial was conducted in Zone 8 instead of Zone 9, but the trial was 

located near the border between the two zones. Samples were analyzed for combined residues of 

mefenoxam and metabolites convertible to 2,6-DMA using an acceptable method, and adequate 

storage stability data are available to support the study.
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Although no residue decline data were included in the submission, adequate residue decline data 

are available for mefenoxam and metalaxyl to support the submitted study. Previously reviewed 

data indicate that residues of mefenoxam/metalaxyl declined or did not increase with increasing 

sampling interval in: (1) basil harvested at 7, 14, and 21 days (DP#s 257785 and 266898, 

4/20/01, N. Dodd); (2) broccoli, cauliflower, and cabbage harvested at 7 and 14 days (PP#

2F04072, 1/15/93, M. Peters); and (3) lettuce harvested at 4-5, 7, and 14 days (DP# 156811, 

6/21/91, S. Bacchus). 

The submitted field trial data, reflecting combined residues of mefenoxam/metalaxyl and 

metabolites convertible to 2,6-DMA, would support a tolerance of 8.0 ppm and a reduced PHI of 

3 days for spinach treated with a soil application of the EC or SL formulation followed by foliar 

application of the WP formulation. (Refer to Appendix II for the tolerance calculation.) 

However, because the submitted data are not representative of all registered uses of mefenoxam 

on spinach (see, for example, the 2.5% granular formulation; EPA Reg. No. 100-798), HED 

recommends against establishing a reduced tolerance for mefenoxam on spinach. The existing 

tolerance of 10 ppm for spinach, established under 40 CFR §180.408, is appropriate. 

Snap bean

IR-4 submitted field trial data for mefenoxam on snap beans. Eight field trials were conducted in 

Zones 1 (NY; 1 trial), 2 (MD; 1 trial), 3 (FL; 1 trial), 5 (WI; 3 trials), 10 (CA; 1 trial), and 11 

(WA; 1 trial) during 2002.

At each test site, one untreated and one treated plot were established. Each treated plot received 

an initial soil surface spray application of a 4 lb ai/gal EC formulation made at planting at ~0.50 

lb ai/A; seed was planted immediately following application on the same day. The at-planting 

application was followed by two foliar directed or broadcast spray applications of a 5% WP 

formulation made at ~0.10 lb ai/A/application, for a total seasonal rate of ~0.70 lb ai/A (~0.8x 

the maximum seasonal application rate of 0.90 lb ai/A for snap bean based on registered soil and 

proposed foliar application). The first foliar application was made 45-79 days after the soil 

application, and the second foliar application was made 7-8 days after the first foliar application. 

All applications were made using ground equipment in spray volumes of 30-57 gal/A; no 

adjuvants were used. Samples of snap beans were collected from each test site at commercial 

maturity, 6-7 days after the final application. At two sites, additional samples were collected 0 

and 13-14 days after final application to assess residue decline. 

Samples from the snap bean field trials were initially analyzed for residues of mefenoxam per se

using an adequate chiral LC/MS method. Samples from the CA trial, including decline samples, 

were subsequently reanalyzed using an adequate GC/MS method that determined combined 

residues of mefenoxam, metalaxyl, and metabolites convertible to the 2,6-DMA moiety as 2,6-

DMA. The LLMV was 0.05 ppm for both methods. Sample storage intervals and conditions are 

reported in Table 4. Adequate concurrent storage stability data were submitted to support the 

crop field trials. 

The study results, reflecting the original analysis for mefenoxam only and re-analysis of the CA 

field trial samples for parent + metabolites, were presented to ChemSAC with a request to use 

conversion factors calculated by dividing the residues obtained on re-analysis of the CA field 
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trial samples by the original values to calculate residues in the remaining field trial samples for 

setting residue values for the risk assessment. The calculated conversion factors are: 1x for 0-

day PHI, 1.8x for the 6- to 7-day PHI, and 3x for the 13- to 14-day PHI. ChemSAC agreed (see 

minutes of 2/25/09 meeting) that parent + metabolites to parent ratios could be used to estimate 

residue levels for risk assessments in snap beans, with the provision that these ratios would not 

necessarily be correct/adequate for these commodities for future risk assessments if refinements 

were necessary.

The results of the snap bean field trials are presented in Table 6. Following one at-planting soil 

application of the 4 lb ai/gal EC formulation at 0.48-0.51 lb ai/A and two broadcast foliar 

applications of the 5% WP at 0.10 lb ai/A/application for total application rates of 0.68-0.71 lb 

ai/A, residues of mefenoxam per se were <0.05-0.168 ppm in/on snap beans harvested at a 13- to 

14-day PHI. Following re-analysis of samples from the CA trial, and recalculation of residues in 

samples from the remaining field trials based on the results of the CA trials, combined residues 

of mefenoxam/metalaxyl and metabolites determined as 2,6-DMA were estimated to be <0.05-

0.282 ppm. 

The residue decline data from the CA trial indicate that residues of mefenoxam generally

declined with increasing PHI. Because residues were <LLMV in/on all samples from the WI

decline trial, residue decline could not be assessed. 

Table 6. Summary of Residue Data from Field Trials with Mefenoxam.

Crop matrix1 Total Applic. 

Rate (lb ai/A)

PHI 

(days)

Residue Levels (ppm)

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

SNAP BEAN (proposed use = 0.4 lb ai/A total application rate foliar only; 6-day PHI)

(proposed + registered use = 0.5 lb ai/A soil + 0.4 lb ai/A foliar for 0.9 lb ai/A total application rate)

Mefenoxam per se

Snap Bean

(Original 

analysis)

0.68-0.71 6-7 16 <0.05 0.168 0.137 0.05 0.061 0.032

Combined residues of mefenoxam/metalaxyl and metabolites convertible to 2,6-DMA

Snap Bean

(Reanalysis/

calculation)

0.68-0.71 6-7 16 <0.05 0.282 0.246 0.05 0.075 0.068

1 Original analysis: samples were originally analyzed for residues of mefenoxam per se. Reanalysis/calculation: 

samples from the CA site were re-analyzed for combined residues of mefenoxam/metalaxyl and metabolites 

convertible to 2,6-DMA; for all other trials, the original residue results were corrected using a conversion factor of 

1.8x.

2

 HAFT = Highest Average Field Trial.

Conclusions. The submitted field trial residue data for snap bean are adequate. Provided the 

label is amended as indicated in OPPTS 860.1200 to specify a maximum of two foliar 

applications, a maximum seasonal application rate of 0.50 lb ai/A for soil applications + 0.2 lb 

ai/A for foliar applications, and a 7-day PHI, the study adequately reflects the proposed use 

pattern for snap bean, and the number and location of field trials are in accordance with OPPTS 

Guideline 860.1500. Samples were initially analyzed for residues of mefenoxam per se using an 

acceptable method, and selected samples were re-analyzed for combined residues of 

mefenoxam/metalaxyl and metabolites convertible to 2,6-DMA using an acceptable method. 

Calculation of combined residues in remaining crop samples using a 1.8x conversion factor was 
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 29 of 49

approved by ChemSAC. Adequate concurrent storage stability data were submitted to support 

the study.

The submitted field trial data, reflecting residues of mefenoxam per se, will support the proposed 

tolerance of 0.20 ppm for snap bean.

 

Caneberry subgroup 13-07A

IR-4 submitted field trial data for mefenoxam on blackberries and raspberries, the representative 

commodities of caneberry subgroup 13-07A. Six caneberry field trials were conducted in the 

U.S. in Zones 2 (NC and NJ; 2 trials), 10 (CA; 2 trials), 11 (WA; 1 trial), and 12 (WA; 1 trial) 

during 2002. Two trials were conducted using blackberry varieties (blackberry and boysenberry), 

and four trials were conducted using raspberry varieties (red and black).

At each test site, one untreated and one treated plot were established. Each treated plot received 

an initial soil surface spray application, directed toward the base of the plants, of a 4 lb ai/gal EC 

formulation made at flowering to early fruiting at ~1.8 lb ai/A. The soil application was followed

by two foliar directed spray applications of a 5% WP formulation made at ~0.10 lb 

ai/A/application to plants bearing fruit, for a total seasonal rate of ~2.0 lb ai/A (0.6x the 

maximum proposed seasonal application rate for caneberries). The first foliar application was 

made 35-45 days after the soil application, and the second foliar application was made 6-7 days 

after the first foliar application. All applications were made using ground equipment in spray

volumes of 30-101 gal/A; no adjuvants were used. Berry samples were collected from each test 

site at commercial maturity, on the day of the final application (0-day PHI). 

Samples from the caneberry field trials were initially analyzed for residues of mefenoxam per se

using an adequate chiral LC/MS method. Samples from the NC and NJ trials and one CA trial 

(02-CA27) were subsequently reanalyzed using an adequate GC/MS method that determines 

combined residues of mefenoxam, metalaxyl, and metabolites convertible to the 2,6-DMA 

moiety as 2,6-DMA. The LLMV was 0.05 ppm for both methods. Sample storage intervals and 

conditions are reported in Table 4. Adequate concurrent storage stability data were submitted to 

support the crop field trials. 

The study results, reflecting the original analysis for mefenoxam only and re-analysis of the NC, 

NJ, and CA field trial samples for parent + metabolites, were presented to ChemSAC with a 

request to use a 1.3x conversion factor, calculated by dividing the average residues obtained on 

re-analysis for each of the three trials by the average residues obtained on original analysis, to 

calculate residues in the remaining field trial samples for setting residue values for the risk 

assessment. ChemSAC agreed (see minutes of 2/25/09 meeting) that parent + metabolites to 

parent ratios could be used to estimate residue levels for risk assessments in caneberry, with the 

provision that these ratios would not necessarily be correct/adequate for these commodities for 

future risk assessments if refinements were necessary.

The results of the caneberry field trials are presented in Table 7. Following one soil surface spray

application of the 4 lb ai/gal EC formulation at 1.75-1.98 lb ai/A and two broadcast foliar 

applications of the 5% WP at 0.10 lb ai/A/application for total application rates of 1.95-2.18 lb 

ai/A, residues of mefenoxam per se were 0.213-0.554 ppm in/on caneberries harvested at a 0-day
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 30 of 49

PHI. Following re-analysis of samples from the NC, NJ, and one CA trials, and recalculation of 

residues in samples from the remaining field trials based on the reanalysis results, combined 

residues of mefenoxam/metalaxyl and metabolites determined as 2,6-DMA were estimated to be 

0.277-0.691 ppm. 

A residue decline trial was not included in the study.

Table 7. Summary of Residue Data from Field Trials with Mefenoxam.

Crop matrix1 Total Applic. 

Rate (lb ai/A)

PHI 

(days)

Residue Levels (ppm)

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

CANEBERRY (proposed use = 3.6 lb ai/A total application rate, soil + foliar applied; 0-day PHI for foliar 

application)

Mefenoxam per se

Caneberries

(Original 

analysis)

1.95-2.18 0 12 0.213 0.554 0.527 0.296 0.329 0.106

Combined residues of mefenoxam/metalaxyl and metabolites convertible to 2,6-DMA

Caneberries

(Reanalysis/

calculation)

1.95-2.18 0 12 0.277 0.691 0.686 0.370 0.412 0.135

1 Original analysis: samples were originally analyzed for residues of mefenoxam per se. Reanalysis/calculation: 

samples from the NC, NJ, and one CA (02-CA27) trials were re-analyzed for combined residues of 

mefenoxam/metalaxyl and metabolites convertible to 2,6-DMA; for all other trials, the original residue results were 

corrected using a conversion factor of 1.3x.

2

 HAFT = Highest Average Field Trial.

Conclusions. The submitted field trial residue data for caneberries are not adequate for a 

permanent registration but will support a conditional registration. The field trial locations are not 

in accordance with 860.1500, and no residue decline data were submitted. To fulfill geographic 

distribution requirements, one additional field trial must be conducted in Zone 5 (raspberry) or 6 

(blackberry). The required field trial should include additional sampling intervals to assess 

residue decline. (Note: Three studies were conducted in Zones 10, 11, and 12 instead of three 

studies in Zone 12 as suggested in OPPTS 860.1500; however, Bernard Schneider, contacted by

Dynamac, indicated that the three trials conducted in Zones 10, 11, and 12 would be sufficient in 

lieu of three studies in Zone 12 as suggested in OPPTS 860.1500.)

The proposed use directions for caneberries on the EC, SL, and WP labels must be amended as 

indicated in OPPTS 860.1200. 

Samples were initially analyzed for residues of mefenoxam per se using an acceptable method, 

and selected samples were re-analyzed for combined residues of mefenoxam and metabolites 

convertible to 2,6-DMA using an acceptable method. Calculation of combined residues in 

remaining crop samples using a 1.3x conversion factor was approved by ChemSAC. Adequate 

concurrent storage stability data were submitted to support the study.

The submitted field trial data, reflecting residues of mefenoxam per se, will support a tolerance 

of 0.70 ppm for caneberry subgroup 13-07A. Refer to Appendix II for the tolerance calculation.
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 31 of 49

Pending submission of the additional required field trial data, the tolerance will be recalculated 

and a revised tolerance proposal may be needed.

Bushberry subgroup 13-07B

IR-4 is proposing to expand the registered use of mefenoxam on blueberry to support the 

bushberry subgroup 13-07B. Blueberry is the representative commodity of the bushberry

subgroup.

No residue data were provided in support of the proposed expanded use. The registered use of 

mefenoxam on blueberry is supported by crop field trial data for metalaxyl on blueberry that 

were reviewed under PP#7F3470/FAP#7H5520 (3/6/87, M. Nelson), reflecting two soil 

applications at 3.6 lb ai/A/application for a maximum seasonal rate of 7.2 lb ai/A, with a 0-day

PHI. The available data were re-assessed for the Residue Chemistry Chapter of the Metalaxyl 

RED which concluded that no additional data were needed for blueberry. A tolerance of 2.0 ppm 

is established for metalaxyl on blueberry. As specified in DP# 223261, the use rates for 

mefenoxam are one-half the rate of metalaxyl, and mefenoxam applications are made in the same 

way as for metalaxyl; therefore, the data for metalaxyl are adequate to support the proposed use 

of mefenoxam.

Conclusions. The registered use of mefenoxam on blueberry is supported by adequate crop field 

trial data for metalaxyl, and the proposed use pattern for mefenoxam on bushberry subgroup 13-

07B is identical to the registered use on blueberry. Because blueberry is the representative 

commodity of the bushberry subgroup, HED has no objections to expanding the registered use to 

cover the crop subgroup provided the revisions requested under Section 860.1200 to the EC and 

SL labels for bushberries are made. The available data for blueberry will support a tolerance of 

2.0 ppm for the bushberry subgroup 13-07B

860.1520 Processed Food and Feed

HED does not require residue data for any processed commodities associated with onion, legume 

vegetables/spinach, snap beans, caneberries, or bushberries. Therefore, data requirements for 

processed food and feed are not relevant to this tolerance petition.

860.1650 Submittal of Analytical Reference Standards

An analytical standard for mefenoxam (expiration date of 2/28/2014) is currently available in the 

National Pesticide Standards Repository (personal communication with Dallas Wright, ACB, 

12/9/09). 
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 32 of 49

860.1850 Confined Accumulation in Rotational Crops

Residue Chemistry Memo No DP#, 2/14/07, W. Britton (RARC Report)

Residue Chemistry Memo DP# 269910, 10/27/00, N. Dodd, A. Lowit, and M. Bonner (MARC Decision)

Residue Chemistry Memo DP# 268454, 10/17/00, N. Dodd, A. Lowit, and M. Bonner (Issues to be presented to 

MARC)

The nature of the residue in rotated crops is adequately understood for mefenoxam, based on 

confined rotational crop studies conducted with metalaxyl on lettuce, sugar beet, and wheat. 

Metabolism of metalaxyl in rotated crops generally proceeds by the same pathways as seen in 

primary crops with the formation of four classes of metabolites: (1) those containing the 2,6-

DMA moiety; (2) those containing the HMMA moiety; (3) those containing a Ring-OH moiety; 

and (4) those containing a benzoic acid moiety. The following differences were noted. Two 

ring-hydroxylated metabolites were detected in rotated lettuce: Metabolite CGA-100255 

accounted for 11% of the TRR in immature lettuce; and a second compound, which would 

represent an N-dealkylation product of CGA-100255, designated N1b aglycone, was detected in 

hydrolysates of aqueous and insoluble fractions, at 16% of the immature lettuce TRR. These 

compounds were also found in mature lettuce with 8% of the TRR as CGA-100255 and 11% as 

N1b aglycone; both were released from glucose conjugates. In rotated wheat grain, the majority

of the identified residues (35.2% out of 43.0% identified) were metabolites oxidized to benzoic 

acid metabolites, including CGA-108905, which was found at 33.7% TRR. 

HED previously concluded that the mefenoxam residues in rotational crops to be regulated for 

the tolerance expression and for dietary assessments are (R)- and (S)-2-[(2,6-dimethylphenyl)-

methoxyacetylamino]-propionic acid methyl ester, its metabolites containing the 2,6-DMA 

moiety, and CGA-94689, each expressed as mefenoxam equivalents, except that 2-

[(methoxyacetyl)(2-methoxy-1-methyl-2-oxoethyl)amino]-3-methylbenzoic acid (CGA-108905) 

would also be included in the risk assessment for cereal grain rotational crops and N-(3-hydroxy2,6-dimethylphenyl)-N-(methoxyacetyl)alanine methyl ester (CGA-100255) would be included in 

the risk assessment for leafy vegetable (Brassica and non-Brassica) rotational crops.

The HED RARC subsequently determined that the residue to be regulated (in the tolerance 

expression) in crop commodities is (R)- and (S)-2-[(2,6-dimethylphenyl)-methoxyacetylamino]-

propionic acid methyl ester and that for risk assessment, the residues of concern in crop 

commodities are metalaxyl/mefenoxam, its metabolites containing the 2,6-DMA moiety, its 

metabolites containing the HMMA moiety, its metabolites containing the Ring-OH moiety, and 

its metabolites containing the benzoic acid moiety. The RARC further noted that CGA-100255 

and CGA-108905 need not be included in future dietary risk assessments since there is little 

likelihood that these metabolites could be recovered by any of the 2,6-DMA common moiety

methods. 
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 33 of 49

860.1900 Field Accumulation in Rotational Crops

Residue Chemistry Memo DP# 333767, 3/7/07, B. Cropp-Kohlligian.

Residue Chemistry Memo No DP#, 2/14/07, W. Britton (RARC Report)

Residue Chemistry Memo DP# 276001, 9/13/01, N. Dodd

Residue Chemistry Memo DP# 269910, 10/27/00, N. Dodd, A. Lowit, and M. Bonner (MARC Decision)

Residue Chemistry Memo DP# 268454, 10/17/00, N. Dodd, A. Lowit, and M. Bonner (Issues to be presented to 

MARC)

Residue Chemistry Memo DP#s 203675 and 206108, 10/17/94, S. Hummel

Field rotational crop data for metalaxyl were previously reviewed. Residues were determined in 

the commodities of rotational broccoli, cabbage, corn, lettuce, red beets, rye, soybeans, sugar 

beets, sweet potatoes, and wheat planted following metalaxyl-treated potatoes, tobacco, and 

wheat (soybean was planted after the wheat primary crop). Application rates were 3-6 lb ai/A for 

potatoes and tobacco and 1-2 lb ai/A for wheat. Plantback intervals ranged from 6-12 months, 

with the exception of winter wheat and rye, which were planted 1-6 weeks after treatment of 

potatoes and 3-19 months after treatment of tobacco. Combined residues of metalaxyl and 

metabolites convertible to 2,6-DMA were determined; recovery data were only provided for 

metalaxyl per se. 

Under the metalaxyl reregistration process, HED concluded (DP#s 203675 and 206108) that the 

available field rotational crop studies were inadequate but could be upgraded by providing 

additional recovery data demonstrating that the enforcement method and the analytical methods 

used for the field rotational crop studies would detect representative metalaxyl metabolites 

containing the 2,6-DMA and HMMA moieties. Additional supporting recovery data for 

metabolites were submitted and reviewed under DP# 276001 and DP# 333767, which indicated 

that the established enforcement method, AG-395 was not adequate for the determination of 

residues of metalaxyl/mefenoxam metabolites CGA-94689, CGA-62826, and P1/P2 in crop

commodities. Method modifications to improve recoveries for metabolites CGA-94689 and 

CGA-62826 were required. 

In consideration of the RARC recommendations for mefenoxam, no additional data are required 

to support the metalaxyl field rotational crop studies. The established plantback intervals for 

mefenoxam on rotated crops are supported by adequate data.

HED notes that tolerances for indirect or inadvertent residues of metalaxyl were previously

established for a number of cereal grain commodities primarily in support of rotation to cereal 

grains following potato. 

860.1550 Proposed Tolerances

Residue Chemistry Memo No DP#, 2/14/07, W. Britton (RARC Report)

Residue Chemistry Memo 223261, 4/24/96, L. Kutney

IR-4, on behalf of the Agricultural Experiment Stations of CA, FL, OR, and GA, is proposing the 

establishment of tolerances for residues of the fungicide mefenoxam, (R)- and (S)-[2,6-

dimethyl(phenyl)-methoxyacetylamine]-propionic acid methyl ester, and its metabolites 

containing the 2,6-dimethylaniline moiety, and N-(2-hydroxy methyl-6-methylphenyl)-N-

(methoxyacetyl)-alanine methyl ester.
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 34 of 49

The HED Risk Assessment Review Committee (RARC) has determined that the residue to be 

regulated (in the tolerance expression) in plant and livestock commodities is (R)- and (S)-2-[(2,6-

dimethylphenyl)-methoxyacetylamino]-propionic acid methyl ester, and that the 

current/reassessed tolerance levels should be retained. 

In connection with registration review of metalaxyl/mefenoxam (DP#368461, N. Dodd, 4/13/10), 

HED recommended for modification of the tolerance expressions for metalaxyl (40 CFR 

§180.408) and mefenoxam (40 CFR §180.546) according to the new compliance/measurement 

policy (Interim Guidance on Tolerance Expressions, Steve Knizner, May 27, 2009) as follows:

Tolerances are established for residues of metalaxyl, including its metabolites and 

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

tolerance levels specified below is to be determined by measuring only metalaxyl 

[methyl N-(2,6-dimethylphenyl)-N-(methoxyacetyl)-DL-alaninate].

Tolerances are established for residues of mefenoxam, including its metabolites 

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

tolerance levels specified below is to be determined by measuring only metalaxyl 

[methyl N-(2,6-dimethylphenyl)-N-(methoxyacetyl)-DL-alaninate].

Tolerances for mefenoxam are currently established under 40 CFR §180.546 and are expressed in

terms of (R)- and (S)-2-[(2,6-dimethyl(phenyl)-methoxyacetylamine]-propionic acid methyl ester, 

its metabolites containing the 2,6-dimethylaniline moiety, and N-(2-hydroxy methyl-6-

methylphenyl)-N-(methoxyacetyl)-alanine methyl ester, each expressed as mefenoxam 

equivalents.

Tolerances for metalaxyl are currently established under 40 CFR §180.408 and are expressed in 

terms of the combined residues of the fungicide metalaxyl [N-(2,6-dimethylphenyl)-N-

(methoxyacetyl) alanine methylester], and its metabolites containing the 2,6-dimethylaniline 

moiety, and N-(2-hydroxy methyl-6-methylphenyl)-N-(methoxyacetyl)-alanine methyl ester, each 

expressed as metalaxyl equivalents. 

HED previously concluded (DP# 223261) that the established tolerances for metalaxyl will be 

adequate to support the use of mefenoxam on the same crops provided that (1) the use rates for 

mefenoxam are one-half the rate of metalaxyl; (2) mefenoxam applications are made in the same 

way as for metalaxyl; and (3) the labels restrict the use of both pesticides concurrently on the 

same crop. 

The registered uses for mefenoxam that are relevant to the subject petition are supported by the 

following metalaxyl tolerances: blueberry at 2.0 ppm, onion, bulb at 3.0 ppm; onion, green at 

10.0 ppm; and spinach at 10.0 ppm. In addition, a tolerance on vegetable, legume, group 6 is 

established at 0.2 ppm, and a tolerance on raspberry is established at 0.5 ppm.

Based on the tolerance expressions recommended by the RARC and by HED in the 

metalaxyl/mefenoxam registration review, and to be consistent with Codex, the tolerance 
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 35 of 49

expression proposed by IR-4 under PP#9E7591 must be revised. The tolerance expression for 

mefenoxam should be stated as follows:

Tolerances are established for residues of mefenoxam, including its metabolites 

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

tolerance levels specified below is to be determined by measuring only metalaxyl 

[methyl N-(2,6-dimethylphenyl)-N-(methoxyacetyl)-DL-alaninate].

HED notes that measuring mefenoxam as metalaxyl would be consistent with Codex.

The proposed and recommended tolerances for the petition are listed in Table 8. 

Pending label amendments, adequate crop field trial data reflecting the proposed use patterns

were submitted for purposes of establishing tolerances on spinach and snap bean. For 

caneberries, an additional field trial conducted in Zone 5 or 6 is required as a condition of 

registration; label amendments are also needed. The tolerance spreadsheet in the Agency’s 

Guidance for Setting Pesticide Tolerances Based on Field Trial Data was utilized in determining 

appropriate tolerance levels for spinach and caneberries. The tolerance spreadsheet could not be 

used to calculate the tolerance for snap bean because ~88% of residues were <LLMV; the 

recommended tolerance for snap bean was based on the maximum observed residues. The 

submitted data used to determine tolerances for snap bean and caneberries reflected analysis of 

samples for mefenoxam per se; the data for spinach reflected analysis for combined residues of 

mefenoxam/metalaxyl and metabolites convertible to 2,6-DMA. The proposed tolerances for 

snap bean and the caneberry subgroup are too high; tolerances should be established at 0.20 ppm 

for snap bean and 0.70 ppm for caneberry subgroup 13-07A.

The submitted crop field trial data for spinach will support a tolerance of 8.0 ppm for spinach; 

however, because the submitted data are not representative of all registered uses of mefenoxam 

on spinach (see, for example, the 2.5% granular formulation; EPA Reg. No. 100-798), HED 

recommends against establishing a reduced tolerance for mefenoxam on spinach. The existing 

tolerance of 10 ppm for spinach, established under 40 CFR §180.408, is appropriate. 

A tolerance for metalaxyl residues in/on legume vegetables exists under 40 CFR §180.408 at 0.2 

ppm for combined residues of parent and metabolites convertible to 2,6-DMA. In IR-4’s 

submission, the data for these combined residues showed values exceeding 0.2 ppm (maximum 

value was 0.282 ppm, and this value was an actual residue value, as opposed to a calculated 

value). However, the HED Risk Assessment Review Committee (RARC) determined (report 

dated 2/14/07) that the residue to be regulated (in the tolerance expression) in plant commodities 

is (R)- and (S)-2-[(2,6-dimethylphenyl)-methoxyacetylamino]-propionic acid methyl ester. 

Therefore, a tolerance under 40 CFR §180.546 for residues of mefenoxam in/on snap beans at 

0.20 ppm is appropriate. 

A tolerance exists under 40 CFR §180.408 for metalaxyl residues in/on raspberry at 0.5 ppm

whereas HED is now recommending a tolerance under 40 CFR §180.546 of 0.70 ppm on the 

caneberry subgroup. The metalaxyl tolerance will remain in 40 CFR §180.408 to support any

uses of metalaxyl on raspberry. 
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 36 of 49

Adequate crop field trial data for metalaxyl reflecting application according to the proposed use 

patterns, but at rates corresponding to twice the maximum proposed single application and 

seasonal rates for mefenoxam, are available for purposes of establishing tolerances on onions and 

bushberries. The available data will support establishment of the proposed tolerances for 

residues of mefenoxam in/on onion, bulb, subgroup 3-07A at 3.0 ppm; onion, green, subgroup 3-

07B at 10 ppm; and bushberry subgroup 13-07B at 2.0 ppm. 

IR-4 noted that in conjunction with establishment of the proposed tolerance for the bushberry

subgroup, the mefenoxam tolerance for lingonberry can be removed.

Codex MRLs, expressed in terms of metalaxyl per se for plant commodities, are established for 

spinach at 0.1 and onion at 0.03 ppm. Canadian MRLs for mefenoxam (metalaxyl-M) are 

covered by MRLs established for metalaxyl, the unresolved isomeric mixture, which are 

expressed in terms of N-(2,6-dimethylphenyl)-N-(methoxyacetyl)-DL-alanine methyl ester, 

including metabolites that can be converted to the 2,6-dimethylaniline moiety, calculated as 

metalaxyl equivalents. Canadian MRLs are established for spinach at 10 ppm, bulb onion at 3.0 

ppm, green onion at 10 ppm, bean at 0.2 ppm, raspberry at 0.2 ppm, and blueberry at 2.0 ppm. 

No Mexican MRLs are established for mefenoxam or metalaxyl. With the adoption of the 

tolerance expression recommended by the RARC, the U.S. tolerance expression will be in 

harmonization with Codex MRLs but not with PMRA MRLs.

Table 8. Tolerance Summary for Mefenoxam.

Commodity

Tolerance (ppm) Comments; Correct Commodity 

Definition Established Proposed Recommended 

Bean, snap, succulent -- 0.35 0.20 

Caneberry, subgroup 13-07A -- 0.80 0.70 Caneberry subgroup 13-07A

Bushberry subgroup 13-07B -- 2.0 2.0

Onion, bulb, subgroup 3-07A -- 3.0 3.0

Onion, green, subgroup 3-07B -- 10.0 10

Spinach -- 8.0 10 The existing tolerance for 

spinach, listed under 40 CFR 

§180.408, is 10.

Lingonberry 2.0 -- Remove Residues on lingonberry will be 

covered by the tolerance on 

bushberry subgroup 13-07B
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 37 of 49

References

DP#: N/A

Subject: PP# 7F3470/FAP# 7H5520/EPA Reg. No. 100-607. Metalaxyl in or on 

Blueberries, Walnuts, Almonds, Almond Hulls, Stone Fruits, Dried Apricots, and 

Prunes. Evaluation of Analytical Method and Residue Data. [Accession Nos. 

265762, 265763, 265764, 265765.] [CB Nos.: 1676, 1677, 1678.]

From: M. Nelson

To: L. Rossi and Toxicology Branch

Date: 3/6/87

MRIDs: 00164649

DP#: 156811

Subject: PP#0F3893 (EPA Reg. Nos. 100-607, 100-608): Metalaxyl Technical: 

(Ridomil® 2E). Tolerance In/On Leafy Vegetables (Excluding Brassica 

Vegetables, Excluding Spinach). Analysis of Residue Data and Analytical 

Method. CBTS #7171.

From: S. Bacchus

To: R. Chambliss/S. Lewis

Date: 6/21/91

MRIDs: 41587800, 41587801

DP#: N/A

Subject: PP# 2F04072: 1. Metalaxyl (Ridomil® 2E Fungicide, EPA Reg. No. 100-607) in 

or on members of the Brassica (cole) leafy vegetables crop grouping; evaluation 

of request for amended registration, analytical method and residue data of mustard 

greens.

From: M. Peters

To: B. Chambliss/S. Lewis

Date: 1/15/93

MRID: 42159801

DP#: 197037

Subject: Metalaxyl (113501) - Case No. 0081. Product and Residue Chemistry Chapters 

for the Reregistration Eligibility Document (RED). CB No. 12906.

From: S. Hummel

To: D. Edwards

Date: 6/14/94

MRIDs: None
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 38 of 49

DP#s: 203675 and 206108

Subject: Metalaxyl (113501) - Reregistration Case No. 0081. Addendum to RED Residue 

Chemistry Chapter, Rotational Crop Studies (GLN 165-1 and 165-2), Supporting 

Storage Stability Data. CB Nos. 13740, 14131

From: S. Hummel

To: J. Loranger

Date: 10/17/94

MRIDs: 42195401, 42196502, 42196503, 41870308, 43317302

DP#: 223261

Subject: Mefenoxam: Replacement of Metalaxyl Technical with Mefenoxam Technical; 

Review of Bridging Data, CBTS No. 16909. PRIORITY 6. TOX 375AA, 

ID #:000100-TOR PRAT CASE #: 039771

From: L. Kutney

To: D. Stubbs and D. McCall

Date: 4/24/96

MRIDs: 43800300, 43800301, 43800322, 43800323, 43889801-43889803, 43889821, 

43896901-43896905

DP#: 268454

Subject: Mefenoxam. Issues to be Presented to the HED Metabolism Assessment Review 

Committee. PC Code 113502; Case No. 290692; Submission No. S553336.

From: N. Dodd, A. Lowit, and M. Bonner

To: G. Kramer

Date: 10/17/00

MRIDs: None

DP#: 269910

Subject: Mefenoxam. Metabolism Assessment Review Committee (MARC) Decision 

Document for Meeting Held on 10/24/00. Chemical #113502. Case #290692. 

Submission #S553336.

From: N. Dodd, A. Lowit, and M. Bonner

To: G. Kramer

Date: 10/27/00

MRIDs: None

DP#s: 257785 and 266898

Subject: PP#9E06005. Mefenoxam (HelixTM) on Herb Subgroup (Crop Subgroup 19-A)

and Mint. Section 3 Registration and Permanent Tolerance Request. Residue 

Chemistry Review: Evaluation of Analytical Methods and Residue Data.

From: N. Dodd

To: R. Forrest/S. Brothers

Date: 4/20/01

MRIDs: 44847601, 44847602
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 39 of 49

DP#: 274194

Subject: PP#9F05044, 9E06005, and 9E06057. Mefenoxam on Canola, Herb Subgroup

(Crop Subgroup 19-A), Fresh Mint, and Various Minor or Tropical Fruits. 

Evaluation of Method Validation Report dated 2/22/01.

From: N. Dodd

To: S. Brothers/R. Forrest and T. Ellwanger/M. Waller

Date: 4/20/01

MRIDs: None

DP#: 276001

Subject: Metalaxyl/Mefenoxam Analytical Method Recovery Data in Plants.

From: N. Dodd

To: M. Waller/T. Ellwanger

Date: 9/13/01

MRID: 44208107

DP#: 324493

Subject: Mefenoxam. Ridomil GoldTM EC (EPA Reg. No. 100-801). Label Amendment 

for Cole Crops, Cucurbits, Lettuce and Grapes.

From: L. Cheng

To: R. Westin/M. Waller

Date: 3/17/06

MRIDs: None

DP#: None

Subject: Metalaxyl/Mefenoxam. Report of the Risk Assessment Review Committee 

(RARC1).

From: W. Britton

To: B. Cropp-Kohlligian 

Date: 2/14/07

MRIDs: None

DP#: 333767

Subject: Mefenoxam. Summary of Analytical Chemistry and Residue Data. PP#s 5F7018 

and 9E6057.

From: B. Cropp-Kohlligian

To: M. Ottley

Date: 3/7/07

MRIDs: 46714701-46714707

DP#: 366407

Subject: Mefenoxam. Amendments for Grapes, Leafy Vegetables except Brassica, and 

Potatoes.

From: N. Dodd

To: M. Waller/T. Gibson

Date: 11/12/09

MRIDs: None
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 40 of 49

Attachments: 

International Residue Limit Status sheet 

Appendix I - Chemical Name and Structure Table

Appendix II-Tolerance Assessment Calculations

Template Version April 2008
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

Page 41 of 49

INTERNATIONAL RESIDUE LIMIT STATUS

Chemical Name: methyl N-

(2,6-dimethylphenyl)-N-

(methoxyacetyl)-Dalaninate

Common Name:

mefenoxam

(metalaxyl-M)

 Proposed tolerance

 Reevaluated tolerance

X Other - Recommended

Date: 03/03/10

Codex Status (Maximum Residue Limits) U. S. Tolerances

No Codex proposal step 6 or above

No Codex proposal step 6 or above for the crops 

requested

Petition Number: PP#9E7591 

DP Barcode: D371307

Other Identifier: 

Residue definition (step 8/CXL): metalaxyl (plant); sum 

of metalaxyl and metabolites containing the 2,6-

dimethylaniline moiety, expressed as metalaxyl 

(livestock).

Metalaxyl-M MRLs are at Step 6, pending resolution of 

the status of metalaxyl CXLs. 

Reviewer/Branch: RAB3 – Nancy Dodd

Residue definition: methyl N-(2,6-dimethylphenyl)-N-

(methoxyacetyl)-DL-alaninate

Crop (s) MRL (mg/kg) (Step 6) Crop(s) Tolerance (ppm)

Caneberry subgroup 13-07A 0.70

Bean, snap, succulent 0.20

Spinach 0.1 (existing CXL 2 for 

metalaxyl)

Spinach Remains at 10

Bushberry subgroup 13-07B 2.0

Lingonberry Remove

Onion, bulb 0.03 (existing CXL 2 for 

metalaxyl)

Onion, bulb, subgroup 3-07A 3.0

Onion, green, subgroup 3-07B 10

Limits for Canada Limits for Mexico1

X No Limits (metalaxyl MRLs apply)

 No Limits for the crops requested

X No Limits

No Limits for the crops requested

Residue definition: Residues of the resolved isomer 

metalaxyl-M are covered by MRLs established for 

metalaxyl, the unresolved isomeric mixture.

N-(2,6-dimethylphenyl)-N-(methoxyacetyl)-DL-alanine 

methyl ester, including metabolites that can be 

converted to the 2,6-dimethylaniline moiety, each 

expressed as metalaxyl equivalents

The following are metalaxyl MRLs:

Residue definition: N/A

A 2004 listing gives numerous crops for both metalaxyl 

and metalaxyl-M, but without tolerance values.

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

Raspberry 0.2

Bean 0.2

Spinach 10
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INTERNATIONAL RESIDUE LIMIT STATUS

Chemical Name: methyl N-

(2,6-dimethylphenyl)-N-

(methoxyacetyl)-Dalaninate

Common Name:

mefenoxam

(metalaxyl-M)

 Proposed tolerance

 Reevaluated tolerance

X Other - Recommended

Date: 03/03/10

Blueberry 2

Onion, bulb 3.0

Onion, green 10

Notes/Special Instructions: S. Funk, 03/01/2010. 1 Mexico adopts Codex MRLs or US tolerances for its export 

purposes.
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

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APPENDIX I. Chemical Names and Structures of Mefenoxam/Metalaxyl and Metabolites. 

Common name;

Company code

Chemical name Chemical structure

Mefenoxam;

CGA-329351

methyl N-(2,6-dimethylphenyl)-N-

(methoxyacetyl)-D-alaninate

H3C

N

O

CH3

O

CH3 H3C

O

H3C

O

Metalaxyl;

CGA-48988

methyl N-(2,6-dimethylphenyl)-N-

(methoxyacetyl)-DL-alaninate

H C3

N

O

CH3

O

H3C CH3

O O

H C3

CGA-62826 N-(2,6-dimethylphenyl)-N-

(methoxyacetyl)alanine

H C3

N

O

CH3

O

H3C CH3

HO O

CGA-94689 N-(2-hydroxymethyl-6-

methylphenyl)-N-

(methoxyacetyl)alanine methyl ester

N

O

CH3

O

CH3

O O

H3C

HO

H C3

CGA-108905 2-[(methoxyacetyl)(2-methoxy-1-

methyl-2-oxoethyl)amino]-3-

methylbenzoic acid

N

O

CH3

O

H3C CH3

O O

H C3

HOOC
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APPENDIX I. Chemical Names and Structures of Mefenoxam/Metalaxyl and Metabolites. 

Common name;

Company code

Chemical name Chemical structure

CGA-100255 N-(3-hydroxy-2,6-dimethylphenyl)-

N-(methoxyacetyl)alanine methyl 

ester

H3C

N

O

CH3

O

H3C CH3

O O

H3C

HO
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

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Appendix II. Tolerance Assessment Calculations.

For each of the crops listed below, the Guidance for Setting Pesticide Tolerances Based on Field 

Trial Data (SOP), along with the tolerance spreadsheet (August 2009 version), was used for 

calculating recommended tolerances. As specified in the SOP, the minimum of the 95% upper 

confidence limit (UCL) on the 95th percentile and the point estimate of the 99th percentile was 

selected as the tolerance value in cases when the dataset was large (greater than 15 samples) and 

reasonably lognormal. For datasets that were small (≤15 samples) and reasonably lognormal, the 

upper bound estimate of the 95th percentile based on the median residue value was compared to 

the minimum of the 95% UCL on the 95th percentile and the point estimate of the 99th 

percentile, and the minimum value was selected as the tolerance value. The rounding procedures 

specified in the SOP were also used.

Caneberry (crop subgroup 13-07A)

The dataset used to establish a tolerance for mefenoxam on caneberries consisted of field trial 

data for blackberries and raspberries (the representative crops of subgroup 13-07A) representing 

application rates of ~2.0 lb ai/A (one soil surface application at ~1.8 lb ai/A and two foliar 

directed spray applications at ~0.10 lb ai/A/application) with a 0-day PHI. Pending requested 

label revisions, the field trial application rates and PHIs are within 25% of the maximum label 

application rate and minimum label PHI, respectively. The field trial PHIs are within 25% of the 

minimum label PHI, the field trial application rates are lower than the maximum label rate of 3.6 

lb ai/A. Because no field trial data were submitted reflecting the maximum label rate, we have 

assumed the petitioner intends to support the maximum label rate used in the field trials, 2.0 lb 

ai/A. The residue values that were entered into the tolerance spreadsheet are provided in Table 

II-1.

All field trial sample results for mefenoxam per se in/on caneberries were above the LLMV 

(LLMV = 0.05 ppm). The caneberry dataset contained 12 samples. Visual inspection of the 

lognormal probability plot (Figure II-1) and the results from the approximate Shapiro-Francia test 

statistic (Figure II-2) indicated that the dataset was reasonably lognormal. 

Using the tolerance spreadsheet, the recommended tolerance is 0.70 ppm for caneberries.

Table II-1. Residue data used to calculate tolerance for mefenoxam on crop subgroup 13-07A.

Regulator: EPA

Chemical: Mefenoxam

Crop: Caneberry

PHI: 0 days 

App. Rate: 1.95-2.18 lb ai/A

Submitter: IR-4

MRID Citation: MRID 47803103

Residues of mefenoxam per se

0.325

0.359

0.279

0.382
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Table II-1. Residue data used to calculate tolerance for mefenoxam on crop subgroup 13-07A.

Regulator: EPA

Chemical: Mefenoxam

Crop: Caneberry

PHI: 0 days 

App. Rate: 1.95-2.18 lb ai/A

Submitter: IR-4

MRID Citation: MRID 47803103

Residues of mefenoxam per se

0.242

0.213

0.267

0.233

0.277

0.313

0.499

0.554

Figure II-1. Lognormal probability plot of mefenoxam field trial data for caneberry.

Lognormal Probability Plot

0.1 1 2 5 10 20 30 50 70 80 90 95 98 99 99.9

1.0000

0.5000

0.2500

0.1250

y = 0.3032x - 1.1551

R

2

 = 0.9473

Percentiles

Concentrations

EPA Mefenoxam Caneberry 0 days 1.95-2.18 lb ai/A IR-4
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Figure II-2. Tolerance spreadsheet summary of mefenoxam field trial data for caneberry.

Regulator: EPA

Chemical: Mefenoxam

Crop: Caneberry

PHI: 0 days 

App. Rate: 1.95-2.18 lb ai/A

Submitter: IR-4

n: 12

min: 0.21

max: 0.55

median: 0.30

average: 0.33

95th Percentile 99th Percentile 99.9th Percentile

0.60 0.60 0.70

(0.70) (0.80) (--)

0.60 0.70 0.80

(0.80) (1.0) (--)

0.80

0.70

1.8

0.9473

p-value > 0.05 : Do not reject lognormality assumption

Approximate 

Shapiro-Francia 

Normality Test 

EU Method I

Normal

UCLMedian95th

95/99 Rule

EU Method II

Distribution-Free

Mean+3SD

Spinach

The dataset used to establish a tolerance for mefenoxam on spinach consisted of field trial data 

representing application rates of ~1.25 lb ai/A (one soil surface application at ~1.0 lb 

ai/A/application and two foliar directed spray applications at ~0.125 lb ai/A/application) with a 

2- to 4-day PHI. The field trial application rates and PHIs are within 25% of the maximum label 

application rate and minimum label PHI, respectively. The residue values that were entered into 

the tolerance spreadsheet are provided in Table II-2.

All field trial sample results for combined residues of mefenoxam and metabolites convertible to 

2,6-DMA in/on spinach were above the LLMV (LLMV = 0.10 ppm). The spinach dataset 

contained 18 samples. Visual inspection of the lognormal probability plot (Figure II-3) and the 

results from the approximate Shapiro-Francia test statistic (Figure II-4) indicated that the spinach 

dataset was reasonably lognormal.

Using the tolerance spreadsheet, the recommended tolerance is 8.0 ppm for spinach.
Mefenoxam Summary of Analytical Chemistry and Residue Data DP#: 371307

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Table II-2. Residue data used to calculate tolerance for mefenoxam on spinach.

Regulator: EPA

Chemical: Mefenoxam

Crop: Spinach

PHI: 2-4 days 

App. Rate: 1.211-1.253 lb ai/A

Submitter: IR-4

MRID Citation: MRID 47803105

Combined residues of mefenoxam/metalaxyl + metabolites convertible to 2,6-DMA

1.47

1.72

1.95

1.98

2.22

2.39

2.64

3.02

3.02

3.11

3.13

3.16

3.43

4.01

4.64

5.02

5.50

6.19
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Figure II-3. Lognormal probability plot of mefenoxam field trial data for spinach.

Lognormal Probability Plot

0.1 1 2 5 10 20 30 50 70 80 90 95 98 99 99.9

7.0000

3.5000

1.7500

0.8750

y = 0.4181x + 1.1029

R

2

 = 0.9824

Percentiles

Concentrations

EPA Mefenoxam Spinach 2-4 days 1.211-1.253 lb ai/A IR-4

Figure II-4. Tolerance spreadsheet summary of mefenoxam field trial data for spinach.

Regulator: EPA

Chemical: Mefenoxam

Crop: Spinach

PHI: 2-4 days 

App. Rate: 1.211-1.253 lb ai/A

Submitter: IR-4

n: 18

min: 1.47

max: 6.19

median: 3.07

average: 3.26

95th Percentile 99th Percentile 99.9th Percentile

6.0 7.0 8.0

(7.0) (8.0) (--)

6.0 8.0 11

(9.0) (12) (--)

9.0

8.0

17

0.9824

p-value > 0.05 : Do not reject lognormality assumption

Approximate 

Shapiro-Francia 

Normality Test 

EU Method I

Normal

UCLMedian95th

95/99 Rule

EU Method II

Distribution-Free

Mean+3SD