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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

 OFFICE OF

CHEMICAL SAFETY AND

POLLUTION PREVENTION

Date: December 6, 2011

MEMORANDUM

SUBJECT: S-Metolachlor. Petition for the Use on Coriander (Cilantro) and Garden Beet 

Leaves. Summary of Analytical Chemistry and Residue Data.

PC Code: 108800 DP Barcode: D392447

Decision No.: 451816 Registration No.: 100-816

Petition No.: 1E7898 Regulatory Action: Section 3

Risk Assessment Type: Single Chemical Case No.: 0001

TXR No.: NA CAS No.: 87392-12-9

MRID No.: 48536501 40 CFR: 180.368

FROM: W. Cutchin, Chemist

Alternative Risk Integration Assessment Team (ARIA)

Inert Ingredients Assessment Branch (IIAB)

Registration Division (RD; 7505P)

THROUGH: S. Hummel, Senior Scientist

Registration Action Branch 4 (RAB4)

Health Effects Division (HED; 7509P)

TO: D. Rate, Ph.D., Team Co-Leader

Section 18 Team

Minor Use and Emergency Response Branch

RD (7505P)

Executive Summary

Under PP#1E7898, the petitioner, Interregional Research Project No.4 (IR-4), on behalf of the 

Agricultural Experiment Station of the IR-4 Project and the Agricultural Experiment Stations of 

New York, North Carolina and South Carolina (coriander (cilantro)); and California, Oklahoma, 

Texas and Tennessee (beet, garden, leaves), request the establishment of tolerances for residues 

of S-metolachlor, including its metabolites and degradates, in or on the commodities in the table 

below. 

Commodity Proposed Tolerance

ppm

Cilantro, leaves, fresh 8.0
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Cilantro, leaves, dried 8.0

Coriander, seed 0.13

Beet, garden, leaves 1.8

S-Metolachlor (an isomer enriched form of metolachlor) is a selective, chloroacetanilide 

herbicide that is applied to a variety of crops as a preplant, preplant incorporated, preemergence, 

or postemergence application, primarily for the control of grass weeds. S-Metolachlor is 

registered for use on a wide variety of crops including: corn, cotton, grasses grown for seed, 

legume vegetables, peanuts, potatoes, safflower, sorghum, sunflower, and tomatoes (40 CFR: 

180.368). Compliance with the tolerance levels specified below is to be determined by

measuring only the sum of free and bound S-metolachlor, S-2-chloro-N-(2-ethyl-6-

methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide, its R-enantiomer, and its metabolites, 

determined as the derivatives 2-(2-ethyl-6-methylphenyl)amino-1-propanol (SYN506357 (Senantiomer of CGA 37913)) and 4-(2-ethyl-6-methylphenyl)-2-hydroxy-5-methyl-3-

morpholinone (SYN 508500 (S-enantiomer of CGA-49751)), calculated as the stoichiometric 

equivalent of S-metolachlor, in or on the commodities.

S-metolachlor is to be applied to coriander (cilantro) as a broadcast, foliar application at 0.64-

0.96 lbs ai/A 30 days before the leaf harvest and 70 days before seed. Use the lower end of Smetolachlor rate range for soils that are relatively coarse textured and the higher rates on fine 

textured soils. S-metolachlor is to be applied to beets grown for leaves as a broadcast, preemergence soil surface treatment at 0.63 -1.26 lbs ai/A after the crop has been planted but before 

the crop and weeds emerge. A second application of S-metolachlor may be made to beets as one 

post emergence, broadcast treatment at 0.63 -1.26 lbs ai/A when plants are at 1 to 2 true leaf 

stage. Use the lower end of S-metolachlor rate range for soils that are relatively coarse textured 

and the higher rates on fine textured soils.

The qualitative nature of metolachlor residues in plants is adequately understood based upon the 

adequate corn, potato, and soybean metabolism studies. The metabolism of metolachlor involves 

conjugation with glutathione, breakage of this bond to form the mercaptan, conjugation of the 

mercaptan with glucuronic acid, O-demethylation of the methyl ether, and conjugation of the

resultant alcohol with a neutral sugar. Residues of concern in plants include metolachlor and its 

metabolites, determined as the derivatives CGA-37913 and CGA-49751. The Agency

previously concluded that the residues of concern for S-metolachlor are the same as for 

metolachlor.

Adequate studies are available depicting the metabolism of metolachlor in ruminants and 

poultry. As in plants, metolachlor residues of concern in livestock commodities include 

metolachlor and its metabolites, determined as the derivatives CGA-37913 and CGA-49751. 

The residues of concern for S-metolachlor in livestock are the same as those for metolachlor.

Adequate methodology is available for enforcing the established and recommended tolerances. 

PAM Vol. II, lists a gas chromatography with nitrogen phosphorous detector (GC/NPD) method 

(Method I) for determining residues in/on crop commodities and a gas chromatography with 

mass spectroscopy detector (GC/MSD) method (Method II) for determining residues in livestock 

commodities. These methods determine residues of metolachlor and its metabolites as either 

CGA-37913 or CGA-49751 following acid hydrolysis. IR-4 and Syngenta have proposed a high 
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pressure liquid chromatography with mass spectroscopy/mass spectroscopy (HPLC/MS/MS)

enantiomer-specific method for the enforcement of the proposed tolerances, Method 1848-01. 

The method uses a chiral HPLC column to separate out the S-enantiomers (SYN506357 and 

SYN508500) of the hydrolysis products CGA-37913 and CGA-49751. This method has been 

determined to be adequate for enforcement purposes.

Adequate data are available on the recovery of metolachlor through Multiresidue Method Testing 

Protocols. The FDA PESTDATA database indicates that metolachlor is completely recovered 

through Method 302, PAM Vol. I.

Coriander (cilantro) fresh, dried and seed samples were analyzed using the “Working Method for 

PR 09595: Analysis of s-Metolachlor in Cilantro as Metabolites s-CGA-37913 (SYN-506357) 

and s-CGA-49751 (SYN-508500), A. Le, Document I.D. Working Method for 09595.06-

BER06.doc, Effective Date: 04-18-08,” a modification of Syngenta Method No. 1848-01. 

Samples of the raw agricultural commodities, leaves and stems, and seed were refluxed in acid 

and partitioned into dichloromethane (DCM). An aliquot was purified with column 

chromatography and concentrated into aqueous acetonitrile. The lower limit of method 

validation (LLMV) for residues of SYN 506357 and SYN 508500 was 0.05 ppm in all matrices. 

Based on the LLMV, the calculated limits of detection (LOD) ranged from 0.0132-0.0175 ppm 

for SYN 506357 and SYN 508500 in coriander (cilantro) fresh, dried and seed samples. The 

calculated limits of quantitation (LOQ) ranged from 0.0359-0.0526 ppm for SYN 506357 and 

SYN 508500 in coriander (cilantro) fresh, dried and seed samples, respectively. The method is 

adequate for data collection.

Previously submitted storage stability data indicates that the residues of metolachlor are stable on 

a variety of commodities for up to 2 yrs. Coriander (cilantro) fresh leaves and stems, dried 

leaves and stems and seed samples were stored frozen for a maximum of 708 days, 702 days, and 

416 days, respectively. The results of the storage stability study with coriander (cilantro)

samples and previously submitted storage stability data are adequate to show that residues of Smetolachlor were stable for the duration of this study.

There are no proposed uses in water, fish, irrigated crops and food handling establishments; 

therefore, discussions of S-metolachlor residues on these topics are not are germane to this 

petition.

There are no coriander (cilantro) or garden beet leaf livestock feed items of regulatory interest;

therefore, a discussion of S-metolachlor residues on livestock food items is not germane to this 

petition.

The submitted study is adequate in number and geographic location of residue field trials. Five 

field trials were conducted in EPA Regions 2 (2), 6, 9, and 10. At all sites, two plots received a 

single broadcast application of S-metolachlor at the approximate rate of 0.64 lb ai/A or 0.96 lb 

ai/A. Coriander (cilantro) fresh leaf and stem samples were harvested approximately 30 (27-34) 

days pre-harvest interval (PHI), after the application and placed into frozen storage shortly after 

harvest. At one site, additional treated plots received a single broadcast application of Smetolachlor at the approximate rate of 0.64 lb ai/A or 0.96 lb ai/A, where coriander (cilantro)
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seed were collected. At another site, additional treated plots received a single broadcast 

application of S-metolachlor at the approximate rate of 0.64 lb ai/A or 0.96 lb ai/A, and 

coriander (cilantro) leaves and stems were collected at 27 days and dried in an oven. No spray

adjuvant was used at the trials. No residue decline studies were submitted.

The analytical results show that after a single foliar broadcast application of S-metolachlor at the 

approximate rate of 0.64 lb ai/A and 0.96 lb ai/A with a 27 to 34-days PHI, the maximum total Smetolachlor residues as parent equivalents were approximately 3.7 ppm and 4.1 ppm in coriander 

(cilantro) fresh leaves and stems, respectively. The maximum total S-metolachlor residues as 

parent equivalents were increased from approximately <0.131 ppm (fresh samples) to 0.834 ppm 

(dried samples) in the 0.64 lb ai/A treated plot. The maximum total S-metolachlor residues as 

parent equivalents were increased from approximately 0.170 ppm (fresh samples) to 2.031 ppm 

(dried samples) in the 0.96 lb ai/A treated plot. The maximum total S-metolachlor residues as 

parent equivalents were <0.131 ppm in coriander (cilantro) seed at both application rates. Based 

on the results of these trials, the appropriate tolerance for residues of S-metolachlor in/on 

coriander (cilantro) leaves is 8.0 ppm. However, the Agency uses the preferred name coriander 

not cilantro for this raw agricultural commodity and, in addition, does not differentiate between 

dry and fresh leaves for coriander (cilantro). Therefore, a revised Section F should be submitted 

to indicate a request for coriander, leaves at 8.0 ppm and the cilantro dried and fresh leaves 

should be removed. The study data indicates that the requested tolerance on coriander, seed at 

0.13 ppm is adequate. 

No new data have been submitted in support of the requested tolerance on beet, garden, leaves. 

The request is based on the currently established tolerance for residues of S-metolachlor on 

Brassica leafy vegetables (Sub-group 5B), of 1.8 ppm. The Chemistry Science Advisory

Council (ChemSAC) has considered the issue and determined that since the use pattern for beet 

greens is the same as that for leafy Brassica (sub group 5B), and beet greens are similar to the 

commodities in the leafy Brassica subgroup 5B, it is appropriate to translate this tolerance of 1.8 

ppm to beet greens. Based on the CHEMSAC determination and that the proposed use pattern 

for beet, garden, leaves is the same as leafy Brassica greens, subgroup 5B, IIAB recommends for 

the proposed tolerance of 1.8 ppm on beet, garden, leaves.

There is no crop associated with this petition which requires residue data for processed fractions. 

Analytical standards for the following compounds related to metolachlor are currently available 

in the EPA National Pesticide Standards Repository.

The rotational crop restrictions listed on the label are appropriate for these proposed uses.

Regulatory Recommendations and Residue Chemistry Deficiencies

IIAB has examined the residue chemistry database for S-metolachlor. Pending receipt of an 

updated Section F for coriander, leaves at 8.0 ppm with the cilantro, dried and fresh leaves 

removed, IIAB has no objection to the establishment of the tolerances described in Table 9, 

below.
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A human health risk assessment is forthcoming.

860.1500 Crop Field Trials

The Agency uses the preferred name coriander not cilantro for this raw agricultural commodity

and, in addition, does not differentiate between dry and fresh leaves for coriander (cilantro). 

Therefore, a revised Section F should be submitted to indicate a request for coriander, leaves at 

8.0 ppm and the cilantro dried and fresh leaves should be removed.

Background

The chemical structure and nomenclature of S-metolachlor and its regulated hydrolytic 

derivatives are presented in Table 1, and the physicochemical properties of S-metolachlor are 

presented in Table 2. 

Table 1. Nomenclature of S-Metolachlor and its Regulated Derivatives

Compound

CH3

N

C2H5

C C

H2

O

Cl

C

CH3

CH2 O

CH3

H

Common name S-Metolachlor

Company experimental name N/A

IUPAC name (S)-2-chloro-N-(2-ethyl-6-methyl-phenyl)-N-(2-methoxy-1-methyl-ethyl)-

acetamide 

CAS name 2-chloro-N-(2-ethyl-6-methylphenyl)-N-[(1S)-2-methoxy-1-methylethyl]-

acetamide

CAS registry number 87392-12-9

End-use product (EP) Dual II Magnum (EPA Reg. No: 100-816)

NH OH

Company experimental name SYN506357 (S-enantiomer of CGA 37913)

IUPAC name (S)-2-[(2-ethyl-6-methylphenyl) amino]-propan-1-ol

CAS name (S)-2-[(2-ethyl-6-methylphenyl) amino]-1-propanol

CAS # 82508-08-5

N

O

O

OH

Company experimental name SYN 508500 (S-enantiomer of CGA-49751)

IUPAC name (S)-4-(2-ethyl-6-methylphenyl)-2-hydroxy-5-methylmorpholin-3-one
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Table 1. Nomenclature of S-Metolachlor and its Regulated Derivatives

CAS name 4-(2-ethyl-6-methylphenyl)-2-hydroxy-5-methyl-3-morpholone

CAS # 61520-54-5

Table 2. Physicochemical Properties of the Technical Grade S-Metolachlor

Parameter Value References (MRID)

Melting point/range Not applicable, liquid at room 

temperature

46829503

pH 7.8 at 25°C (1% aqueous dispersion)

Density 1.117 g/cm3 at 20°C

Water solubility (25°C) 0.48 g/L

Solvent solubility mg/L at 25°C Completely miscible with methanol, 

acetone, toluene, n-octanol, n-hexane, 

ethyl acetate, dichloromethane

Vapor pressure at 25°C 2.8 x 10-5 mm Hg

Dissociation constant (pKa) No dissociation constant in pH range 2-

12

Octanol/water partition coefficient Log 

(Kow) 3.05 at 25°C

UV/visible absorption spectrum Neutral: 534 l/mol.cm @ 266.4 nm

 443 l/mol.cm @ 274.4 nm

Acidic: 534 l/mol.cm @ 266.4 nm

 444 l/mol.cm @ 274.4 nm

Basic: 534 l/mol.cm @ 266.4 nm

 411 l/mol.cm @ 274.4 nm

860.1200 Directions for Use

The petitioner provided a text listing of proposed uses in Section B of the petition. Apply Smetolachlor to coriander (cilantro) formulated as Dual MAGNUM (EPA Reg. No.: 100-816) as a 

broadcast, foliar application (0.64-0.96 lbs ai/A) at 30 days before the leaf harvest and 70 days 

before seed. Use the lower end of S-metolachlor rate range for soils that are relatively coarse 

textured and the higher rates on fine textured soils. Apply S-metolachlor to beets grown for 

leaves as a broadcast, pre-emergence soil surface treatment at 0.63 -1.26 lbs ai/A after the crop 

has been planted but before the crop and weeds emerge. A second application of S-metolachlor 

to beets may be made as one post emergence, broadcast treatment at 0.63 -1.26 lbs ai/A when 

plants are at 1 to 2 true leaf stage. Use the lower end of S-metolachlor rate range for soils that 

are relatively coarse textured and the higher rates on fine textured soils.

The proposed uses are presented below in Table 3. 

Table 3. Summary of Proposed Directions for Use of S-Metolachlor.

Applic. Timing; 

Type; and Equip.

(minimum volume)

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 

Limitations

Coriander (cilantro)
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Table 3. Summary of Proposed Directions for Use of S-Metolachlor.

Applic. Timing; 

Type; and Equip.

(minimum volume)

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 

Limitations

Broadcast Foliar

(20 GPA)

7.62 lb/gal 

EC

[100-816]

0.64-0.96 1 0.96

30-

leaves

70-

seeds

REI: 24hrs

Beet, garden, leaves (for varieties grown for tops only)

Postemergence to 

Soil & Broadcast 

Foliar

(10-40 GPA)

7.62 lb/gal

EC

[100-816]

0.63-1.26 2 2.52 30

First appl. broadcast, 

pre-emergence soil 

surface treatment Second 

appl. when plants are at 

1 to 2 true leaf stage.

REI: 24hrs

Conclusions: The proposed use directions are adequate.

860.1300 Nature of the Residue - Plants

The qualitative nature of metolachlor residues in plants is adequately understood based upon the 

adequate corn, potato, and soybean metabolism studies. The metabolism of metolachlor involves 

conjugation with glutathione, breakage of this bond to form the mercaptan, conjugation of the 

mercaptan with glucuronic acid, O-demethylation of the methyl ether, and conjugation of the 

resultant alcohol with a neutral sugar. A minor pathway may involve sugar conjugation of 

metolachlor directly to the corresponding oxo-compounds. Residues of concern in plants include 

metolachlor and its metabolites, determined as the derivatives CGA-37913 and CGA-49751. 

The Agency previously concluded that the residues of concern for S-metolachlor are the same as 

for metolachlor (DP# 226780, L. Kutney, 11/15/96).

The Agency has also reviewed plant metabolism data on S-metolachlor from field tests on 

soybeans and corn, in vitro tests on corn seedlings, and greenhouse tests on seedlings of corn, 

sorghum, soybeans and peanuts (DP#s 278742 and 279110, S. Kinard, 8/15/03). These data 

support Syngenta’s assertion that the metabolism of S-metolachlor in plants is similar to that for 

the racemic mixture. The data did not address whether there is any conversion of the S-isomers 

of metolachlor or its metabolites to the R-isomer forms; however, HED previously concluded 

that such conversion of isomers in plants is not likely to be significant.

860.1300 Nature of the Residue - Livestock

Adequate studies are available depicting the metabolism of metolachlor in ruminants and 

poultry. Metolachlor is rapidly metabolized and almost totally eliminated in the urine and feces 

of ruminants (goats), non-ruminants (rats), and poultry. Metolachlor per se was not detected in 

any of the excreta or tissues. As in plants, metolachlor residues of concern in livestock 

commodities include metolachlor and its metabolites, determined as the derivatives CGA-37913 

and CGA-49751. The residues of concern for S-metolachlor in livestock are the same as those 
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for metolachlor.

The Agency has also reviewed livestock metabolism data on S-metolachlor (DP#s 278742, S. 

Kinard, 8/15/03). Data from a goat metabolism study indicated that S-metolachlor was readily 

absorbed and extensively metabolized by goats via glutathione conjugation and/or oxidation 

reactions. Oxidized metabolites were also conjugated with glucuronic acid. Data from a poultry

metabolism study indicated that S-metolachlor was also extensively metabolized via O 

demethylation and subsequent glucuronic acid conjugation or oxidation to dihydroxy or 

carboxylic acid metabolites that may also be conjugated with glucuronic acid.

860.1340 Residue Analytical Methods

Enforcement methods: Adequate methodology is available for enforcing the established and 

recommended tolerances. PAM Vol. II, Pesticide Regulation Section 180.368, lists a GC/NPD 

method (Method I) for determining residues in/on crop commodities and a GC/MSD method 

(Method II) for determining residues in livestock commodities. These methods determine 

residues of metolachlor and its metabolites as either CGA-37913 or CGA-49751 following acid 

hydrolysis. 

IR-4 and Syngenta have proposed an HPLC/MS/MS enantiomer-specific method for the 

enforcement of the proposed tolerances, Method 1848-01. This method has been previously 

reviewed by HED (DP# 296904, R. Loranger, 4/17/06). The method uses a chiral HPLC column 

to separate out the S-enantiomers (SYN506357 and SYN508500) of the hydrolysis products 

CGA-37913 and CGA-49751. 

Data-gathering methods: Coriander (cilantro) fresh, dried and seed samples were analyzed for 

residues of S-metolachor using the “Working Method for PR 09595: Analysis of s-Metolachlor 

in Cilantro as Metabolites s-CGA-37913 (SYN-506357) and s-CGA-49751 (SYN-508500), A. 

Le, Document I.D. Working Method for 09595.06-BER06.doc, Effective Date: 04-18-08,” a 

modification of Syngenta Method No. 1848-01, dated June 26, 2003 entitled “Analytical Method 

for the Enantioselective Determination of Residues of s-Metolachlor as Metabolites SYN506357 and SYN-508500 in Agricultural Commodities by Chiral High Performance Liquid 

Chromatograph with Mass Spectrometric Detection.” 

Samples of the raw agricultural commodities, leaves and stems, and seed were refluxed in 6N 

HCL. The cooled extract was filtered and residues were partitioned from a pH adjusted aliquot 

into DCM and dried with sodium sulfate. An aliquot was purified with alumina column 

chromatography and concentrated into 30% acetonitrile (aqueous). The residues were quantified 

by reversed phase HPLC with positive ion atmosphere pressure chemical ionization tandem mass 

spectrometric detection (MS/MS). 

The residue analytical method for S-metolachlor residues in/on coriander (cilantro) samples was 

validated both prior to and concurrently with field samples. For method validation, control 

samples of coriander (cilantro) fresh, dried and seed were fortified with SYN 506357 and SYN 

508500 at 0.05, 0.5, 2, and 5.0 ppm. Concurrent recoveries were conducted at 0.05, 0.5, and 1 

ppm. The LLMV for residues of SYN 506357 and SYN 508500 was 0.05 ppm in all matrices. 
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Several validation recoveries for SNY-508500 (s-CGA 49751) on seed were lower than the 

acceptable range of 70-120%. Method validation recoveries on seed ranged from 59-72% (avg. 

66 ± 5%) and concurrent recoveries ranged from 50-84% (avg. 67 ± 14%). 

Table 4. Summary of Recoveries of S-Metolachlor from Coriander (cilantro)

Matrix Analyte Spike 

level 

(mg/kg)

Sample 

size (n) Recoveries (%) Mean ± std dev

Method Validation

Fresh 

leaves and 

stems

SYN-506357

(s-CGA 37913)

0.05

0.5

6 94, 92, 78, 80, 81 83 ± 8

0.5 6 92, 87, 86, 82, 81, 83 85 ± 4 85.2 ± 7

5.0 6 72, 93, 92, 92, 81, 93 87 ± 9

Fresh 

leaves and 

stems

SYN-508500

(s-CGA 49751)

0.05 6 74, 76, 78, 76, 76, 74 76 ± 2

0.5 6 79, 78, 79, 72, 81, 82 79 ± 4 77.6 ± 3

0.5 6 79, 78, 76, 79, 85, 74 78 ± 4

Dried 

leaves and 

stems

SYN-506357

(s-CGA 37913)

0.05 3 89, 100, 96 95 ± 6

0.5 3 77, 77, 74 76 ± 2 89.3 ± 16

2 6 71, 83, 85, 120, 81, 118 93 ± 21

Dried 

leaves and 

stems

SYN-508500

(s-CGA 49751)

0.05 3 72, 84, 74 77 ± 6

0.5 3 62, 62, 62 62 ± 0 83.0 ± 18

2 6 87, 105, 113, 110, 77, 88 97 ± 15

Seed SYN-506357

(s-CGA 37913) 0.05 3 78, 84, 85 82 ± 4

81 ± 3

0.5 3 82, 82, 76 80 ± 3

Seed SYN-508500

(s-CGA 49751) 0.05 5 66, 64, 64 65 ± 1

66 ± 5

0.5 3 72, 70, 59 67 ± 7

Concurrent Validation

Fresh 

leaves and 

stems

SYN-506357

(s-CGA 37913) 0.05 7 96, 84, 108, 100, 92, 86 91 ± 12

86 ± 11

0.5 5 84, 90, 86, 74, 74 82 ± 7

Fresh 

leaves and 

stems

SYN-508500

(s-CGA 49751) 0.05 7

70, 84, 72, 80, 92, 100, 

98 83 ± 12

82 ± 11

0.5 4 80, 78, 76, 70 76 ± 4

Dried 

leaves and 

stems

SYN-506357

(s-CGA 37913)

0.05 3 84, 108, 86 93 ± 13

0.5 3 71, 79, 73 74 ± 4 82 ± 11

1.0 3 80, 82, 77 79 ± 2

Dried 

leaves and 

stems

SYN-508500

(s-CGA 49751)

0.05 3 76, 85, 101 87 ± 12

0.5 3 72, 72, 74 73 ± 1 88 ± 16

1.0 3 109, 108, 96 104 ± 7

Seed SYN-506357

(s-CGA 37913) 0.05 5 80, 76, 94, 106, 84 88 ± 4

81 ± 13

0.5 3 67, 71, 71 70 ± 2

Seed SYN-508500 0.05 5 65, 76, 78, 78, 84 76 ± 7 67 ± 14
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Table 4. Summary of Recoveries of S-Metolachlor from Coriander (cilantro)

Matrix Analyte Spike 

level 

(mg/kg)

Sample 

size (n) Recoveries (%) Mean ± std dev

(s-CGA 49751) 0.5 3 50, 50, 52 51 ± 1

Based on recoveries at the LLMV, the LOD (std. dev. x one-tailed t-statistic) were calculated. 

The LOQ (3 x LOD) were also calculated. The LLMV, LOD and LOQ for SYN-506357 and 

SYN-508500 in/on the three matrices are listed below:

Table 5. Summary of S-Metolachlor Analytical Method Limits

Commodity Analyte Calculated LOD

(ppm)

Calculated LOQ

(ppm)

LLMV

(ppm)

Coriander 

(cilantro) Fresh 

Samples

SYN-506357

SYN-508500

0.0145

0.0132

0.0436

0.0396

0.05

0.05

Coriander 

(cilantro) Dried 

Samples

SYN-506357

SYN-508500

0.0160

0.0175

0.0480

0.0526

0.05

0.05

Coriander 

(cilantro) Seed 

Samples

SYN-506357

SYN-508500

0.0154

0.0120

0.0463

0.0359

0.05

0.05

Conclusions: There are adequate enforcement methods available. The data collection method 

was adequate for the determination of S-metolachlor residues in coriander (cilantro)

commodities.

860.1360 Multiresidue Methods

Adequate data are available on the recovery of metolachlor through Multiresidue Method Testing 

Protocols. The FDA PESTDATA database indicates that metolachlor is completely recovered 

through Method 302, PAM Vol. I (3rd ed., revised 10/97).

860.1380 Storage Stability

Adequate storage stability data are available for crop commodities. Previously submitted data 

(DP# 292881, S. Kinard, 8/15/03) indicate that: CGA-37913 is stable at ≤-10°C for at least 2 

years in corn (grain and forage), peanut, potato (tubers, wet peel and flakes), soybean (hulls and 

meal) and tomatoes, for at least 29 months in cottonseed oil, and for at least 37 months in 

cottonseed and corn oil; and CGA-49751 is stable at ≤-10°C for at least 2 years in corn (grain, 

forage, and oil), peanuts, potatoes (tubers, wet peel and flakes), soybeans (hulls and meal) and 

tomatoes, and for at least 37 months in cotton seed and cottonseed oil. In addition, storage 

stability studies conducted concurrently with previously submitted asparagus, carrot, and green 

onion field trials indicate that both analytes are stable at -20oC for at least 14.1 months in 

asparagus, 24.3 months in carrots, and 21.7 months in green onions. 

Coriander (cilantro) fresh leaves and stems, dried leaves and stems and seed samples were stored 

frozen for a maximum of 708 days, 702 days, and 416 days, respectively. Recoveries of SYN-
Page 11 of 21

506357 and SYN-508500 from stored coriander (cilantro) samples were corrected for concurrent 

recoveries.

The maximum frozen storage intervals for field treated coriander (cilantro) fresh leaves and 

stems, dried leaves and stems, and seed samples in this study were 708 days, 702 days, and 416 

days respectively. The results of the storage stability study showed that recoveries of Smetolachlor residues in/on coriander (cilantro) fresh leaves and stems were 52% (corrected 70%) 

and 72% (corrected 87%) for SYN-506357 and SYN-508500, respectively. The recoveries of Smetolachlor residues in/on coriander (cilantro) dried leaves were 84% (corrected 88%) and 62% 

(corrected 82%) for SYN-506357 and SYN-508500, respectively. The recoveries of Smetolachlor residues in/on coriander (cilantro) seed were 92% (corrected 110%) and 63% 

(corrected 80%) for SYN-506357 and SYN-508500, respectively. 

Table 6. Stability of S-Metolachlor in Coriander (cilantro) Samples Following Storage at -20oC

Matrix 

(RAC or 

Extract)

Analyte Stored Sample 

Recovery (%)

Concurrent 

Recovery

(%)

Stored Sample 

Average 

Corrected 

Recovery (%)1

Actual 

Storage 

Duration

(days)

Interval of 

Demonstrated 

Storage Stability 

(days)

Coriander 

(cilantro) fresh 

leaves and 

stems

SYN506357 53, 52, 52 75 70

708 720 SYN508500 71, 70, 74 82 87

Coriander

(cilantro) dried 

leaves and 

stems

SYN506357

67/83

70/106

72/104

81/111 88

624 - 702 678 - 686

SYN508500

58/76

52/66

55/66

71/80 82

Coriander 

(cilantro) 

seed

SYN506357

72/112

99/70

83/114

85/81 110

366 - 416 399 - 413

SYN508500

50/79

73/54

50/69

80/77 80

1Average Corrected Recovery (%) = 100 x [Average Stored Sample Recovery (%) ÷ Average Concurrent Recovery 

(%)] 

Conclusions: The previously submitted storage stability data indicates that the residues of 

metolachlor are stable on a variety of commodities for up to 2 yrs. The results of the storage 

stability study with coriander (cilantro) samples and previously submitted data are adequate to 

show that residues of S-metolachlor were stable for the duration of this study. 

860.1400 Water, Fish, and Irrigated Crops

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

860.1460 Food Handling

There are no proposed uses that are germane to this guideline topic.
Page 12 of 21

860.1480 Meat, Milk, Poultry, and Eggs

There are no coriander (cilantro) or garden beet leaf feed items of regulatory interest, therefore a 

discussion of S-metolachlor residues on livestock food items is not germane to this guideline 

topic.

860.1500 Crop Field Trials

Coriander (cilantro)

DER References: 48536501.der.doc

The IR-4 has submitted field trial data for S-metolachlor on coriander (cilantro). Five field trials 

were conducted in the 2006-growing season, one in South Carolina (EPA Region 2), one in 

Georgia (EPA Region 2), one in Texas (EPA Region 6), one in New Mexico (EPA Region 9), 

and one in California (EPA Region 10). 

At each trial, there were at least two treated plots. At all sites, two of the plots received a single 

broadcast application of S-metolachlor at the approximate rate of 0.64 lb ai/A or 0.96 lb ai/A. 

Coriander (cilantro) fresh leaf and stem samples were harvested approximately 30 (27-34) days 

after the application and placed into frozen storage shortly after harvest. At the New Mexico 

trial, additional treated plots received a single broadcast application of S-metolachlor at the 

approximate rate of 0.64 lb ai/A or 0.96 lb ai/A, where coriander (cilantro) seed were collected. 

At the California trial, additional treated plots received a single broadcast application of Smetolachlor at the approximate rate of 0.64 lb ai/A or 0.96 lb ai/A, timed to be approximately 30 

days before harvest, when coriander (cilantro) fresh leaves and stems were dried. All 

applications were made within 17-36 gallons per acre spray solution and no spray adjuvant was 

used at the trials. 

Coriander (cilantro) fresh leaves and stems samples were collected between 27-34 days after the 

final application at all sites. Coriander (cilantro) seed samples were collected at 70 days after the 

application. Coriander (cilantro) leaves and stems were collected at 27 days and dried in an oven 

at 155° F before sampling.

The analytical results show that after a single foliar broadcast application of S-metolachlor at the 

approximate rate of 0.64 lb ai/A and 0.96 lb ai/A with a 27 to 34-days pre-harvest interval (PHI), 

the maximum total S-metolachlor residues as parent equivalents were approximately 3.7 ppm 

and 4.1 ppm in coriander (cilantro) fresh leaves and stems, respectively. The maximum total Smetolachlor residues as parent equivalents were increased from approximately <0.131 ppm 

(fresh samples) to 0.834 ppm (dried samples) in the 0.64 lb ai/A treated plot. The maximum 

total S-metolachlor residues as parent equivalents were increased from approximately 0.170 ppm 

(fresh samples) to 2.031 ppm (dried samples) in the 0.96 lb ai/A treated plot. The concentration 

factor from fresh samples to dried samples was 6-12X. The maximum total S-metolachlor 

residues as parent equivalents were <0.131 ppm in coriander (cilantro) seed at both application 

rates. No residue decline studies were submitted.
Page 13 of 21

Table 7. Residue Data from Coriander (cilantro) Crop Field Trials with S-Metolachlor

Trial ID

(City,State/Year) Region Crop/ Variety Commodity Total Rate(lbs ai/A)

PHI 

(days)

Residue 

SYN506357

(ppm)

Residue 

SYN508500

(ppm)

SYN-506357 

as parent 

equivalents1

(ppm) 

SYN-508500 

as parent 

equivalents2

(ppm)

S-metolachlor 

total residues 

as parent 

equivalents 

(ppm)

06-SC*09

(Charleston, SC, 

2006)

2

Coriander 

(cilantro)/ 

Santo

Fresh leaves

0.63

34

0.090 

0.096

0.103 

0.092

0.132

0.141

0.117

0.105

0.249

0.246

0.88 0.124 

0.118

0.153 

0.122

0.182

0.173

0.174

0.139

0.356 

0.312

06-GA*11

(Tifton, GA, 2006) 2

Coriander 

(cilantro)/ 

Santo 

Monogerm

Fresh leaves

0.64

27

1.682 

2.008

0.821 

0.924

2.473

2.952

0.936

1.053

3.409

4.005

0.97 1.992 

1.873

1.163 

1.112

2.928

2.753

1.326 

1.268

4.254

4.021

06-TX*37

(Weslaco, TX, 

2006)

6

Coriander 

(cilantro)/ 

leisure

Fresh leaves

0.64

32

<0.05 

<0.05

<0.05 

<0.05

<0.074 

<0.074

<0.057 

<0.057

<0.131

<0.131

0.96 0.068 

0.056

0.059 

0.055

0.100 

0.082

0.067

0.063 

0.167

0.145

06-CA*109

(Salinas, CA, 

2006)

10

Coriander 

(cilantro)/ 

Santo

Fresh leaves

0.65

27

<0.05 

<0.05

<0.05 

<0.05

<0.074 

<0.074

<0.057 

<0.057

<0.131

<0.131

0.97 <0.05 

<0.05

0.079 

0.089

<0.074 

<0.074

0.090 

0.101

0.164

0.175

Dried Leaves

0.66

28

0.174* 0.507* 0.256 0.578 0.834

0.98 0.594* 1.016* 0.873 1.158 2.031

06-NM14

(Las Cruces, NM, 

2006)

9

Coriander 

(cilantro)/ 

Santo

Fresh leaves

0.64

28

<0.05 

<0.05

<0.05 

0.05

<0.074 

<0.074

<0.057

0.057

<0.131

<0.131

0.97 0.090 

0.057

0.112 

0.066

0.132

0.084

0.128

0.075

0.260

0.159

Seed

0.64

70

<0.05 

<0.05

<0.05* 

<0.05*

<0.074 

<0.074

<0.057 

<0.057

<0.131

<0.131

0.96 <0.05 

<0.05

<0.05* 

<0.05*

<0.074 

<0.074

<0.057 

<0.057

<0.131

<0.131

*Result is the average of the duplicate analyses of a single sample.

1

SYN-506357 values were multiplied by 1.47 to obtain parent equivalents. Values of 0.074 ppm represent the 

method’s LOQ as parent equivalents.

2

SYN-508500 values were multiplied by 1.14 to obtain parent equivalents. Values of 0.057 ppm represent the 

method’s LOQ as parent equivalents.

Table 8. Summary of Residue Data from Crop Field Trials with S-Metolachlor

Commodity Total 

Applic. Rate

(lb ai/A)

PHI1

(days) Analyte

Residue Levels (ppm)2

n Min. Max. HAFT3 Median Mean

Std. 

Dev.

Coriander 

(cilantro) fresh 

leaves/stems

0.63 – 0.65 27 – 34

Total Smetolachlor 

as parent 

equivalents

10 <0.13 4.0 3.7 <0.13 0.87 1.53

Coriander 

(cilantro) fresh 

leaves/stems

0.88 – 0.97 27 – 34 10 0.14 4.2 4.1 0.22 1.0 1.6

Coriander 

(cilantro) dried 

leaves/stems

0.66 27 1 0.83 0.83 - 0.83 0.83 -
Page 14 of 21

Table 8. Summary of Residue Data from Crop Field Trials with S-Metolachlor

Commodity Total 

Applic. Rate

(lb ai/A)

PHI1

(days) Analyte

Residue Levels (ppm)2

n Min. Max. HAFT3 Median Mean

Std. 

Dev.

Coriander 

(cilantro) dried 

leaves/stems

0.98 27 1 1.6 1.6 - 1.6 1.6 -

Coriander 

(cilantro) 

seed

0.64 70 2 <0.13 0.13 - <0.13 <0.13 -

Coriander 

(cilantro) 

seed

0.96 70 2 <0.13 <0.13 - <0.13 <0.13 -

1

PHI = Post harvest interval

2

Sum of SYN-506357 and SYN-508500 residues as parent equivalents

3HAFT = Highest Average Field Trial

Conclusions: The submitted study is adequate in number and geographic location of residue 

field trials. The study data indicates that the highest residues for coriander (cilantro) were found 

in fresh leaves at the higher application rate. This data was entered into the OECD MRL

Calculator. Based on the results of these trials, the Calculator indicates that the appropriate 

tolerance for residues of S-metolachlor in/on coriander (cilantro) leaves is 8.0 ppm. However, 

the Agency uses the preferred name coriander not cilantro for this raw agricultural commodity

and, in addition, does not differentiate between dry and fresh leaves for coriander (cilantro). 

Therefore, a revised Section F should be submitted to indicate a request for coriander, 

leaves at 8.0 ppm and the cilantro dried and fresh leaves should be removed.

The study data indicates that the requested tolerance on coriander, seed at 0.13 ppm is adequate. 

IIAB recommends for the requested tolerance.

Beet, Garden, Leaves

No new data have been submitted in support of the requested tolerance on beet, garden, leaves.

The IR-4 Project Headquarters received a request from California, Texas, Tennessee, and

Oklahoma for the use of S-metolachlor as herbicide to control weeds in beet, garden, leaves

production. The request is based on the currently established tolerance for residues of Smetolachlor on Brassica leafy vegetables (Sub-group 5B), of 1.8 ppm. The ChemSAC

(4/6/2011) has considered the issue:

“...Tolerances for S-metolachlor are published in 40 CFR § 180.368 (a) (2). Both the 

Brassica leafy vegetables and the turnip greens tolerances were established 17-Sep-2010, 

in connection with PP#9E7607, based on data on the representative commodity mustard 

greens. These data were translated to turnip greens.

Tolerances have already been established for residues of S-metolachlor on vegetable, 

root, exc sugarbeet, subgroup 1B at 0.3 ppm (Established 17-Sep-2008, in connection 
Page 15 of 21

with PP#3E6787), and beet, sugar, root at 0.5 ppm and beet, sugar, tops, at 15 ppm (also 

established 17-Sep-2008, but in connection with PP#6E4638). A tolerance for residues 

of S-metolachlor on leaves of root and tuber vegetables (Crop Group 2) would not be 

appropriate because there are not tolerances on the corresponding roots (all of Crop 

Group 1). A tolerance for residues of S-metolachlor on Carrot of 0.20 ppm was proposed 

in connection with PP#7E4916, and was increased to 0.40 ppm in connection with 

PP#9E7607.

The maximum seasonal application rate on sugarbeets is 3.81 lb ai/A, with no more than 

2.53 lb ai/A applied postemergence. The single application rate on sugarbeets is 2.53 lb 

ai/A. On carrots, a maximum of one application of 1.9 lb ai/A is allowed with a 64 day

PHI. On leafy Brassica (sub-group 5B), a maximum of one application of 1.27 lb ai/A is 

allowed with a 30 day PHI.

The use pattern for sugar beets allows much more S-metolachlor to be applied than to 

leafy Brassica (sub-group 5B); therefore, it would be inappropriate to translate the 

sugarbeet data to beet greens. However, since the use pattern for beet greens is the same 

as that for leafy Brassica (sub group 5B), and beet greens are similar to the commodities 

in the leafy Brassica subgroup 5B, it is appropriate to translate this tolerance of 1.8 ppm 

to beet greens.”

Conclusions: Based on the CHEMSAC determination and that the proposed use pattern for beet, 

garden, leaves is the same as leafy Brassica greens, subgroup 5B, IIAB recommends for the 

proposed tolerance of 1.8 ppm on beet, garden, leaves.

860.1520 Processed Food and Feed

There is no crop associated with this petition which requires residue data for processed fractions. 

860.1650 Submittal of Analytical Reference Standards

Analytical standards for the following compounds related to metolachlor are currently available 

in the EPA National Pesticide Standards Repository (DP#s 369005 & 375955, S. Hummel, 

6/15/10; expiration data in parentheses): metolachlor (11/10/2010); S-metolachlor (8/1/2012); 

metolachlor derivative CGA-37913 (4/30/2010); metolachlor derivative CGA-49751 

(4/30/2011); metolachlor, ethane sulfonic acid sodium salt (CGA-354743, 4/1/2011); and 

metolachlor, oxanilic acid (CGA-51202, 4/1/2011).

860.1850/860.1900 Confined/Field Accumulation in Rotational Crops

D369005 and D375955, S. Hummel, 6/15/10

Confined and field rotational data requirements were recently examined (DP# 369005 and 

375955, S. Hummel, 6/15/10). An adequate confined rotational crop study is available, although 

additional information pertaining to the study remains outstanding. The residues of concern in 

rotated crops are the same as in the primary crops, S-metolachlor, its R-enantiomer, and its 

metabolites determined as CGA-37913 and CGA-49751. HED has determined that adequate 
Page 16 of 21

field rotational crop data have been submitted which support the existing rotational crop 

restrictions on the label for EPA Reg. Nos. 100-816 pending additional label amendments (i.e., 

Rotational crop directions for crops with a 60-day plantback interval must be amended to 

prohibit a second application of S-metolachlor to any of these crops replanted within 60 days of 

the original application.). 

Conclusions: Although additional data for the confined rotational crop study remains 

outstanding, it is not a deficiency for this petition. Rotational crop directions for crops with a 60-

day plantback interval have been amended to prohibit a second application of S-metolachlor to 

any of these crops replanted within 60 days of the original application. This is no longer a 

deficiency for S-metolachlor petitions.

860.1550 Proposed Tolerances

Tolerances are currently established under 40 CFR §180.368 for residues of S-metolachlor, 

including its metabolites and degradates, in or on the commodity(s), as defined. Compliance with 

the tolerance levels specified in the following table below is to be determined by measuring only 

the sum of free and bound S-metolachlor, S-2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-

methoxy-1-methylethyl)acetamide, its R-enantiomer, and its metabolites, determined as the 

derivatives, 2-(2-ethyl-6-methylphenyl)amino-1-propanol and 4-(2-ethyl-6-methylphenyl)-2-

hydroxy-5-methyl-3-morpholinone, calculated as the stoichiometric equivalent of S-metolachlor, 

in or on the commodity.

The submitted coriander (cilantro) study is adequate in number and geographic location of 

residue field trials and supports the proposed tolerance. The Agency uses the preferred name 

coriander not cilantro for this raw agricultural commodity and, in addition, does not differentiate 

between dry and fresh leaves for coriander (cilantro). Therefore, a revised Section F should be 

submitted to indicate a request for coriander, leaves at 8.0 ppm and the cilantro dried and fresh 

leaves should be removed. The study data indicates that the requested tolerance on coriander, 

seed at 0.13 ppm is adequate. 

Based on the CHEMSAC determination and that the proposed use pattern for beet, garden, 

leaves is the same as leafy Brassica greens, subgroup 5B, IIAB recommends for the proposed 

tolerance of 1.8 ppm on beet, garden, leaves.

No maximum residue limits (MRLs) for S-metolachlor on coriander have been established or 

proposed by Codex, Canada, or Mexico. No MRLs for S-metolachlor on beet, garden, leaves

have been established or proposed by Codex or Mexico. An MRL for S-metolachlor on beet, 

garden, leaves has been established in Canada. However, beet, garden, leaves are not a 

significant import/export commodity and are not expected to be a trade irritant with Canada. 

Table 9. Tolerance Summary for S-metolachlor.

Commodity Proposed 

Tolerance (ppm)

RD-Recommended 

Tolerance (ppm) Correct Commodity Definition

Cilantro, leaves, fresh 8.0 NA

Cilantro, leaves, dried 8.0 NA

Coriander, seed 0.13 0.13
Page 17 of 21

Table 9. Tolerance Summary for S-metolachlor.

Commodity Proposed 

Tolerance (ppm)

RD-Recommended 

Tolerance (ppm) Correct Commodity Definition

Beet, garden, leaves 1.8 1.8

Coriander, leaves NA 8.0

References

DP Number: D369005, D375955

Subject: S-Metolachlor. Petition for the Establishment of Permanent Tolerances for New 

Uses on Bushberry Subgroup 13-07B; Caneberry Subgroup 13-07A; Carrot; 

Cucumber; Leafy Brassica Greens Subgroup 5B; Melon Subgroup 9A; Okra; 

Bulb Onion Subgroup 3-07A; Green Onion Subgroup 3-07B; Sesame Seed; 

Sorghum; and Turnip Greens. Summary of Analytical Chemistry and Residue 

Data.

From: S. Hummel 

To: B. Daiss

Dated: 6/15/10

MRIDs: 47829401-08, 48020601

DP#: D226780

Subject: Replacement of Metolachlor Technical (Racemic Metolachlor) with AlphaMetolachlor (formerly called Chiral Metolachlor) Technical; Review of Bridging 

Data.

From: L. Kutney

To: R. Griffin

Dated: 11/15/96

MRIDs: 43928901-03, 43928939-42

DP Number: D274328

Subject: Metolachlor and S-Metolachlor Residue Chemistry Chapter for the Tolerance 

Reassessment Eligibility Decision (TRED)

From: S. Kinard

To: C. Jarvis

Dated: 2/28/02

MRIDs: NA

DP Number: D278742, D279110

Subject: S-Metolachlor. Information Supporting the Assertion That the Metabolism of Smetolachlor Is Essentially the Same as for the Racemic Mixture.

From: S. Kinard

To: S. Kinard

Dated: 8/15/03

MRIDs: 45499603, 45499604, 45499605, 45533103
Page 18 of 21

DP#: D296904

Subject: PP# 3E6787. S-Metolachlor. Petition for Tolerances on Various Crops, Crop 

Groups, and Livestock Commodities. Summary of Analytical Chemistry and 

Residue Data.

From: R. Loranger

To: B. Madden/S. Jackson

Dated: 4/17/06

MRIDs: 45499609, 45499610, 46046501-06

DP#: D292881

Subject: PP#s: 7F04897, 9E06055, 7E04916, 2E06374, 4E04420, 8E05029, and 8E05030. 

Revised Metolachlor and S-metolachlor Residue Chemistry Chapter for the 

Tolerance Reassessment Eligibility Decision (TRED) and Registration for Use on 

Asparagus, Carrots, Cotton, Horseradish, Green Onions, Peppers, Rhubarb, Sugar 

Beet, Sunflower, and Swiss Chard.

From: S. Kinard

To: H. Jamerson

Dated: 8/15/03

MRIDs: 44378401, 44908701, 45544701

DP#s: D332846, D332847, D332848, D332849, D350604, D350942, D351174, 

D351226

Subject: S-Metolachlor. Amended Use Directions for Sorghum and Soybeans; Revisions 

to Rotational Crop Restrictions; Registrant’s Responses to Deficiencies Noted in 

the Revised S-Metolachlor TRED. Summary of Analytical Chemistry and 

Residue Data.

From: D. McNeilly

To: E. Wilson/J. Miller and R. Louie/N. Anderson

Dated: 10/21/08

MRIDs: 46829501-04, 47121701-02, 47304701-02

Attachments: 

International Residue Limit Status Sheet

Tolerance/MRL Spreadsheet
Page 19 of 21

ATTACHMENT I 

International Residue Limits 

S-metolachlor (108800; 11/28/2011)

Summary of US and International Tolerances and Maximum Residue Limits 

Residue Definition:

US Canada Mexico

2

Codex3

40 CFR: 180.368 sum of 

free and bound Smetolachlor, S-2-chloro-N-

(2-ethyl-6-methylphenyl)-N-

(2-methoxy-1-

methylethyl)acetamide, its Renantiomer, and its 

metabolites, determined as 

the derivatives, 2-(2-ethyl-6-

methylphenyl)amino-1-

propanol and 4-(2-ethyl-6-

methylphenyl)-2-hydroxy-5-

methyl-3-morpholinone 

calculated as the 

stoichiometric equivalent of 

S-metolachlor 

2-chloro-N-(2-ethyl-6-

methylphenyl)-N-[(1S)-2-

methoxy-1-methylethyl)acetamide 

and 2-chloro-N-(2-ethyl-6-

methylphenyl)-N-[(1R)-2-

methoxy-1-

methylethyl)acetamide, including 

the metabolites 2-[(2-ethyl-6-

methylphenyl)amino]-1-propanol 

and 4-(2-ethyl-6-methylphenyl)-2-

hydroxy-5-methyl-3-morpholinone

None

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

US Canada Mexico2 Codex3

Coriander, seed 0.13

Beet, garden, tops 1.8 0.8 garden beet tops

Coriander, leaves 8.0

Completed: M. Negussie; 11/29/2011

1

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

not those proposed by the applicant.

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

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

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

fat portion of the sample. MRLs indicated as proposed have not been finalized by the CCPR and the CAC.
Page 20 of 21

ATTACHMENT II 

Tolerance-Assessment Calculations

The submitted U.S. residue data for coriander (cilantro), fresh leaves (10 data points) were 

entered into the OECD MRL Calculator in order to determine appropriate tolerance levels.

Residues (mg/kg) n

0.145 1

0.159 1

0.164 1

0.167 1

0.175 1

0.26 1

0.312 1

0.356 1

4.021 1

4.254 1

S-metolachlor

Cilantro Fresh

USA

0.88 – 0.97 lb ai/A

Total number of data (n) 10

Percentage of censored data 0%

Number of non-censored data 10

Lowest residue 0.145

Highest residue 4.254

Median residue 0.218

Mean 1.001

Standard deviation (SD) 1.655

Correction factor for censoring (CF) 1.000

Proposed MRL estimate

- Highest residue 4.254

- Mean + 4 SD 7.623

- CF x 3 Mean 3.004

Unrounded MRL 7.623

Rounded MRL 8
Page 21 of 21