UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

OFFICE OF

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

MEMORANDUM

	Date:	09/FEB/2007

	Subject:	Clethodim.  Section 3 Registration for the Following Uses of Clethodim on Flax, Seed; Hops, Dried Cones; Asparagus; Herb Subgroup 19A; Sesame, Seed; Legume Vegetable Group 6 (Except Soybean); Safflower, Seed; Safflower, Meal; and Leafy Greens Subgroup 4A.  Summary of Analytical Chemistry and Residue Data.  Petition Numbers: 3E6555, 5E6977, 4E6836, 4F6895, and 5E6978.

		DP Number: 334913, 313466, 	Decision Number:  353916, 353895, 359333, 361915

		323147, 313517, 323146, 323145

		PC Code:  121011	MRID Numbers:  46353807, 46353808

		40 CFR 180.458	Chemical Class:  Herbicide

	From:	Debra Rate, Ph.D., Biologist

		Alternative Risk Integration and Assessment (ARIA) Team

		Risk Integration and Minor Use Emergency Response (RIMUER) Branch

		Registration Division (RD) (7505P)

	Through:	William Cutchin, Acting Branch Senior Scientist

		Technical Review Branch (TRB)/ARIA

		RD (7505P)

		And

	Chemistry Science Advisory Council (ChemSAC)

		Health Effects Division (HED) (7509P)

	To:	Barry O’Keefe, Senior Biologist

		Registration Action Branch 3 (RAB3)

		HED (7509P)

Executive Summary

Clethodim is a cyclohexenone herbicide used for control of annual and perennial grass weeds in broad leaf crops. Clethodim is a post-emergence herbicide used against a wide range of annual and perennial grasses.

Clethodim products are currently registered for a variety of use sites including agricultural crops and non-crop areas.  For example, the labels for two emulsifiable concentrate (EC) clethodim products, Prism (also known as Select) EC® (12.6% active ingredient or ai, EPA Reg. No. 59639-78) and Select 2 EC (25% ai, EPA Reg. No. 59639-3) permit application to commercial and residential sites and on other non-crop or non-planted areas including rights-of-way such as railroads, highways, roads, dividers, medians, pipelines, public utility lines, pumping stations, transformer stations and substations, around airports, electric utilities, commercial buildings, manufacturing plants, storage yards, rail yards, fence lines, parkways, ornamental gardens, walkways, patios, greenhouse benches, along driveways and around golf courses.

Permanent tolerances have been established under 40 CFR §180.458(a)(1) and (4) for the combined residues of the herbicide clethodim ((E)-(±)-2-[1-[[(3-chloro-2-propenyl)oxy]imino]propyl]-5-[2-(ethylthio) propyl]-3-hydroxy-2-cyclohexen-1-one) and its metabolites containing the 2-cyclohexen-1-one moiety in/on the fat, meat, and meat byproducts of cattle, goats, hogs, horses, poultry, and sheep at 0.2 ppm; milk at 0.05 ppm; eggs at 0.2 ppm; cotton, undelinted seed at 1.0 ppm; potato at 0.5 ppm; soybean at 10.0 ppm; cotton, meal at 2.0 ppm; and soybean, soapstock at 15.0 ppm.

In addition, permanent tolerances are established under 40 CFR §180.458(a)(3) for the combined residues of clethodim and its metabolites containing the 5-(2-ethylthiopropyl)cyclohexene-3-one and 5-(2-ethylthiopropyl)-5-hydroxycyclohexene-3-one moieties and their sulphoxides and sulphones, expressed as clethodim, in/on the following commodities:

Alfalfa, forage	………………………	6.0 ppm

Alfalfa, hay	………………………	10 ppm

Bean, dry, seed	………………………	2.5 ppm

Beet, sugar, molasses	………………………	1.0 ppm

Beets, sugar, roots	………………………	0.20 ppm

Beets, sugar, tops	………………………	1.0 ppm

Brassica, heat and stem, subgroup 5A

………………………

3.0 ppm

Brassica, leafy greens, subgroup 5B

………………………

3.0 ppm

Canola, meal	………………………	1.0 ppm

Canola, seed	………………………	0.50 ppm

Cranberry	………………………	0.50 ppm

Clover, forage	………………………	10.0 ppm

Clover, hay	………………………	20.0 ppm

Flax, meal	………………………	1.0 ppm

Flax, seed	………………………	0.50 ppm

Leafy petioles subgroup 4B	………………………	0.60 ppm

Lettuce, leaf	………………………	2.0 ppm

Melon subgroup 9A	………………………	2.0 ppm

Mustard, seed	………………………	0.50 ppm

Onion, dry bulb	………………………	0.20 ppm

Onion, green	………………………	2.0 ppm

Peanut	………………………	3.0 ppm

Peanut, hay	………………………	3.0 ppm

Peanut, meal	………………………	5.0 ppm

Peppermint, tops	………………………	5.0 ppm

Potato, granules/flakes	………………………	2.0 ppm

Radish, tops	………………………	0.70 ppm

Spearmint, tops	………………………	5.0 ppm

Spinach	………………………	2.0 ppm

Squash / cucumber subgroup 9B	………………………	0.50 ppm

Strawberry	………………………	3.0 ppm

Sunflower, meal	………………………	10.0 ppm

Sunflower, seed	………………………	5.0 ppm

Turnip, greens	………………………	3.0 ppm

Vegetables, fruiting, group 8	………………………	1.0 ppm

Vegetable, root, except sugar beet, subgroup 1B

………………………

1.0 ppm

Vegetable, tuberous and corm, subgroup 1C

………………………

1.0 ppm

Time-limited tolerances (listed as expired on 4/30/03) were established under 40 CFR §180.458(a)(2) for the combined residues of clethodim and its metabolites containing the 5-(2-ethylthiopropyl) cyclohexene-3-one and 5-(2-ethylthiopropyl)-5-hydroxycyclohexene-3-one moieties and their sulphoxides and sulphones, expressed as clethodim, in/on tomato paste at 3 ppm, and tomato puree at 2 ppm.

Additional tolerances on individual crops and the establishment of crop group tolerances (which will eliminate any single crop tolerance of that group) are requested in these petitions.  The petitioner has requested tolerances of clethodim defined as the combined residues of the herbicide clethodim and its metabolites containing the 2-cyclohexen-1-one moiety in/on the following raw agricultural commodities (RACs):

Flax, seed	………………………	0.5 ppm

Hops, dried cones	………………………	0.50 ppm

Asparagus	………………………	2.0 ppm

Herb subgroup 19A	………………………	10 ppm

Leafy greens subgroup 4A	………………………	2.0 ppm

Ciltranto, leaves	………………………	2.0 ppm

The petitioner has requested tolerances of clethodim defined as the combined residues of clethodim and its metabolites containing the 5-(2-ethylthiopropyl)cyclohexene-3-one and 5-(2-ethylthiopropyl)-5-hydroxycyclohexene-3-one moieties and their sulphoxides and sulphones in/on the following commodities:

Sesame, seed	………………………	0.40 ppm

Legume vegetable group 6	………………………	3.0 ppm

Safflower, meal	………………………	10.0 ppm

Safflower, seed	………………………	5.0 ppm

Metabolism studies for clethodim in/on the RACs carrots, soybeans, and cotton have been conducted and reviewed (PP#9F3743, MRIDs 41030137 & 41030138, M. Nelson, 12/MAR/1990).  The available metabolism studies on soybean, cotton, and carrots included soybean foliage, cotton foliage, and carrot leaves.  The metabolism in these crops and crop commodities is similar.  HED previously concluded that additional metabolism data may be required for future petitions on crops other than root crops and oil seed crops.  However, metabolism data for soybean foliage, cotton foliage, and carrot leaves can support the proposed use on each requested RAC in these petitions.  The residues of concern are clethodim and its metabolites containing the 5-(2-ethylthiopropyl) cyclohexene-3-one and 5-(2-ethylthiopropyl) -5-hydroxycyclohexene -3-one moieties and their sulphoxides and sulphones.

Metabolism studies of [propyl-1-14C]-clethodim in a lactating goat and laying hens were previously reviewed (PP#9F3743, MRID# 41030139 & 41030140, M. Nelson, 12/MAR/1990).  The nature of the residue in ruminants and poultry is adequately understood for the purposes of the subject petitions.  HED previously concluded that the residues of concern are clethodim and its metabolites containing the 2-cyclohexen-1-one moiety.  The proposed use of clethodim on safflower will only have a minor contribution to the dietary burden of beef and dairy cattle, and poultry, and no contribution to the dietary burden of swine.  There will be no impact on the established tolerances of livestock commodities based on these additions to the respective dietary burdens.  Accordingly, the current tolerances for livestock commodities are adequate.  However, there are no tolerances on foliage of legume commodities, and thus there must be restrictions placed on the label for the grazing of treated fields and the feeding of treated leaves and/or foliage to livestock.

To support the proposed uses, the petitioner conducted adequate field trials with clethodim on asparagus, hops, dried cones, sesame, flax, legume vegetable crop group 6, except soybean (snap beans, lima beans, dry pea, and succulent pea plus previously reviewed dry bean trials), vegetable, leafy greens crop subgroup 4A (leaf lettuce (previously reviewed), spinach (previously reviewed), and head lettuce), herb crop subgroup 19A (basil (fresh and dried) and chive (fresh and dried)).  Based on the similarity of sunflower and safflower, the petitioner has requested that the tolerances for sunflower, seed and sunflower, meal be translated to a tolerance for safflower, meal and safflower, seed.

The formulation used to apply clethodim to the requested RACs was Prism® 0.94 EC, containing 12.6% clethodim (ai) by weight and 87.4% inert ingredients as an emulsifiable concentrate.  The requested usage pattern was two broadcast foliar applications at a maximum rate of 0.25 lb ai/A (2.0 pints formulation per acre) per application to be made per season, for a total seasonal application rate of 0.5 lb ai/A.  The minimum requested pre-harvest interval (PHI) was 1 day (asparagus), and the maximum PHI was 70 days (sunflower and safflower).  The label for Prism® 0.94 EC recommends that a crop oil concentrate, consisting of a minimum 80% oils and 15% emulsifier, always be used as an adjuvant with this herbicide, usually at a concentration of 1% volume/volume in the finished spray volume.

Adequate methodology is available for enforcement of the proposed tolerances through the use of FDA Multiresidue Methods.  The analytical method used to assay clethodim residues in/on the requested RACs was RM-26B-3 (a modification of RM-26B-2) or RE 45601 (also adapted from Valent method RM-26B), which was validated for the analyses of residues of clethodim sulfoxide and its metabolite (5-hydroxy clethodim sulfone) in/on green onions, leaf lettuce, and cabbage.  Briefly, samples were extracted with methanol and then partitioned with dichloromethane.  After evaporation, the samples were oxidized with hydrogen peroxide, methylated with acidic methanol and then cleaned up on a silica gel 60 column and eluted with a hexane/acetone/methanol mixture.  Finally, the samples were analyzed for combined clethodim residues (dimethylester sulfone (DME) and 5-hydroxy dimethylester sulfone (DME-OH)) by gas chromatography with flame photometric detection, in the sulfur mode (GC/FPD-S).  In the analytical results, DME and DME-OH were reported as clethodim equivalents.  Only one crop, hops, dried cones, had residues below the limit of quantitation (LOQ) (<0.50 ppm) for combined total residues of clethodim (DME and DME-OH).

Clethodim has been demonstrated to be stable over the period of time the study samples were harvested and analyzed for each of the requested RACs.  The concurrent recoveries of clethodim (DME and DME-OH) for the submitted trials were within the excepted range of 70-120%.  An exception was the concurrent recovery of succulent pea at 62%.  There is no reason to believe that the residues of clethodim were unstable, or that the analytical method was not reliable under the conditions of these studies.  The recoveries of clethodim residues in each matrix will not have an impact on the recommendations of this action.

  SEQ CHAPTER \h \r 1 The submitted flax field trial data are adequate and reflect the proposed use pattern.  When flax seed sampled 12-18 days following the second application, maximum combined residues of clethodim were 0.41 ppm.  Tolerances were previously established for flax seed and flax meal at 0.5 ppm and 1.0 ppm, respectively.  No processing studies were previously submitted for flax.  The tolerance on flax meal was based on data translated from canola.  The submitted field trial data for herb crop subgroup 19A are adequate and reflect the proposed use pattern.  The RACs submitted to fulfill the guideline requirements of this crop group were basil, fresh and dried, and chives, fresh and dried.  When the basil and chive plots were sampled 20-22 days following the second application, the maximum combined residues of clethdim were 1.32 ppm and 2.16 ppm, respectively for fresh samples and 6.32 ppm and <0.24 ppm, respectively for dried samples. The submitted hops field trial data are adequate and reflect the proposed use pattern.  When hops sampled 20-21 days following the second application, maximum combined residues of clethodim were <0.50 ppm.  The submitted asparagus field trial data are adequate and reflect the proposed use pattern. When asparagus sampled 1 day following the second application, maximum combined residues of clethodim were 0.99 ppm.  The submitted field trial data for sesame are adequate and reflect the proposed use pattern.  When sesame seed sampled 13-15 days after the second application, maximum combined residues were 0.28 ppm.  The submitted field trial data for the leafy greens crop subgroup 4A are adequate and reflect the proposed use pattern.  The petitioner submitted field trial data for head lettuce, with and without wrapper leaves.  The maximum combined residues on lettuce, head, when sampled 13-15 days following the second application were <0.56 ppm (with wrapper leaves) and <0.34 ppm (wrapper leaves removed).  This new data combined with previously reviewed field trial data (spinach and leaf lettuce) fulfill the guideline requirements for leafy greens crop subgroup 4A.  The submitted field trial data for vegetable, legume crop group 6 are adequate and reflect the proposed use pattern.  The RACs submitted to fulfill the guideline requirements of this crop group were snap beans, dry pea, lime bean, shelled pea, edible-podded pea combined with previously submitted dry bean data. When the treated plots were sampled 16-31 days following the second application, the maximum combined residues of clethodim were 0.46 ppm for snap beans, 1.24 ppm for dry pea, 0.65 for lima bean, 2.55 ppm for shelled pea, 1.84 ppm for edible-podded pea.

Processing studies were submitted for both flax seed and sesame seed.  All of the processing factors determined in the submitted studies, except for sesame oil, are less than 1.2X which is the level at which residues in processed commodities may be of concern.  If the highest average field trial (HAFT) residues X Processing Factor > tolerance on sesame seed, then a tolerance is required, otherwise the RAC tolerance is sufficient.  The processing factors determined by these studies will not raise the residues above the tolerances recommended by ARIA for these RACs.  Therefore, tolerances on sesame, oil; sesame, meal; flax, oil; and flax, meal are not required.

The results of a confined rotational crop study of [ring-4,6-14C]-clethodim with carrots, lettuce, and wheat (MRID 41030211) indicated that there is no need for field rotational crop trials.  A 1- month plantback interval for crops rotated with alfalfa was specified (DP Num: 236382, M. Collantes, et. al, 10/FEB/1998).  The use directions submitted with the current petitions do not specifically address rotational crops.  The directions for use on fallow or nonproducing agricultural land state do not plant any crop for 30 days after application unless clethodim is registered for use on that crop.

The crop field trials submitted by the petitioner are adequate to support the proposed uses.  Both the analytical method and recoveries of residues in each matrix are adequate to support the establishment of tolerances.

Regulatory Recommendations and Residue Chemistry Deficiencies

Based on an effort to harmonize tolerances with Codex and MRL, the tolerance requests for clethodim should be defined as the combined residues of clethodim and its metabolites containing the 5-(2-ethylthiopropyl)cyclohexene-3-one and 5-(2-ethylthiopropyl)-5-hydroxycyclohexene-3-one moieties and their sulphoxides and sulphones (PP# 4F4340, DP Num: 203378, J. Morales, 31/JAN/1995).  The following include recommendations and deficiencies for the following petitions.

1.  PP#3E6555:  A revised Section F for the commodity flax, seed must be submitted redefining clethodim as the combined residues of clethodim and its metabolites containing the 5-(2-ethylthiopropyl)cyclohexene-3-one and 5-(2-ethylthiopropyl)-5-hydroxycyclohexene-3-one moieties and their sulphoxides and sulphones, and changing the proposed tolerance from 0.5 ppm to 0.6 ppm as recommended.  The label must be changed to match the proposed use pattern of Section B.

2.  PP#5E6977:  A revised Section F must be submitted to the Agency redefining clethodim as the combined residues of clethodim and its metabolites containing the 5-(2-ethylthiopropyl)cyclohexene-3-one and 5-(2-ethylthiopropyl)-5-hydroxycyclohexene-3-one moieties and their sulphoxides and sulphones for hops, dried cones and aspasparagus, and changing the proposed tolerance to 1.7 ppm for asparagus.  The label must be changed to match the proposed use patterns of Section B.

3.  PP#4E6836:  A revised Section F must be submitted to the Agency redefining clethodim as the combined residues of clethodim and its metabolites containing the 5-(2-ethylthiopropyl)cyclohexene-3-one and 5-(2-ethylthiopropyl)-5-hydroxycyclohexene-3-one moieties and their sulphoxides and sulphones for herb subgroup 19A.  The separate tolerance request for cilantro leaves must be removed from the Section F, as cilantro leaves are a member of herb subgroup 19A.  The proposed tolerance of 10 ppm must be changed to match the tolerance recommended by ARIA of 12.0 ppm.  The label must be changed to match the proposed use pattern of Section B.

4.  PP#5E6978:  A revised Section F must be submitted to the Agency redefining clethodim as the combined residues of clethodim and its metabolites containing the 5-(2-ethylthiopropyl)cyclohexene-3-one and 5-(2-ethylthiopropyl)-5-hydroxycyclohexene-3-one moieties and their sulphoxides and sulphones for leafy greens subgroup 4A.  The label must be changed to match the proposed use pattern of Section B.

5.  PP#4F6895:  A revised Section F for sesame seed must be submitted to the Agency requesting a tolerance of 0.35 ppm to concur with the recommended tolerance.  The petitioner must change this same Section F to correct the commodity definition to crop group 6, vegetable legume (except soybean) and change the proposed tolerance to 3.5 ppm.  The label must be changed to match the proposed use patterns of Section B.  With the exception of crop group 6, vegetable legume (except soybean), which the PHI must be changed to 30 days for the group to match the longest PHI submitted for dry pea.  Therefore a revised Section B must also be submitted to the Agency.  The petitioner must submit a revised label to bring the usage pattern for safflower to match that of the proposed use pattern of Section B and sunflower, from which a direct translation of supporting data was used.  This includes increasing the PHI from 14 to 70 days.  Also, no tolerances were requested for the foliage of legume vegetables, thus the label must include a statement restricting the grazing of fields or feeding of treated leaves/foliage to livestock.

6.  The label must be revised to include the general warning statement “Do not plant any crop for 30 days after application unless clethodim is registered for use on that crop.”

7.  The petitioner must resubmit reference standards for both DME and DME-OH to update expired samples which were previously submitted (June 1993).

  SEQ CHAPTER \h \r 1 Pending the results of the forthcoming human health risk assessment, receipt of standards, and receipt of the revised Section Fs, Section Bs, and labels, the Agency recommends establishing permanent tolerances for the combined residues of clethodim and its metabolites containing the 5-(2-ethylthiopropyl)cyclohexene-3-one and 5-(2-ethylthiopropyl)-5-hydroxycyclohexene-3-one moieties and their sulphoxides and sulphones, expressed as clethodim, in/on leafy greens, subgroup 4A at 2.0 ppm; flax, seed at 0.6 ppm; hop, dried cones at 0.5 ppm; asparagus at 1.7 ppm; herb subgroup 19A at 12.0 ppm; sesame, seed at 0.35 ppm; vegetable, legume, Crop Group 6 (except soybean) at 3.5 ppm; safflower, meal at 10.0 ppm; and safflower, seed at 5.0 ppm.  The tolerances for the individual crop groups of bean, dry, seed at 2.5 ppm, lettuce, leaf at 2.0 ppm, and spinach at 2.0 ppm must be removed.  The established tolerance for flax, meal at 1.0 ppm must be removed.

Background

Clethodim, the active ingredient in Prism® Herbicide and Prism® EC, is a systemic postemergence herbicide used on various crops to control annual and perennial grasses.

TABLE 1.  Test Compound Nomenclature

Common name	Clethodim

Company experimental name	RE45601

IUPAC name (()-2-[(E)-1-[(E)-3-chloroallyloxyimino]propyl]-5-[2-(ethylthio)propyl]- 3-hydroxycyclohex-2-enone

CAS name (E,E)-(()-2-[1-[[(3-chloro-2-propenyl)oxy]imino]propyl]-5-[2-(ethylthio) propyl]-3-hydroxy-2-cyclohexen-1-one

CAS #	99129-21-2

End-use product/(EP)	Prism® 0.94 EC Herbicide

TABLE 2.	Physicochemical Properties of the Technical Grade Test Compound

Parameter	Value	Reference

(MRID#)

Melting point/range	Not Applicable

	Boiling point/range	Decomposes below boiling point.	46124103

pH	4.11,2	46124103

Specific gravity	1.14 1g/ml at 20oC	46124103

Water solubility 	0.54 g/100 ml  (pH 7.0) I,2	46124103

Solvent solubility 	> 90 g/100 ml  in most solvents	46124103

Vapor pressure at 20oC	<1 x 10-2 mPa1 at 20oC	46124103

Octanol/water partition coefficient log (KOW) 	4.51 (21oC)	3

UV/visible absorption spectrum	Study in progress.1  There is no record of this value in any reviews.  However, an early review (PP#9F3743, M. Nelson, 3/12/90) confirmed that all 830 Series requirements have been fulfilled.	--

1    From “Product Chemistry Review of Clethodim Technical,” Shyam B. Mathur, PhD, 6/29/04, DP Barcode 297251, US EPA Registration No. 51036-UEI.

2    The value of this parameter was reported in the MRID without specifying a temperature of testing.

3    S.T. Ha (1994) Determinations of Octanol/Water Partition Coefficients of Clethodim, Clethodim Sulfone, Clethodim Imine Sulfone and Clethodim Oxazole Sulfone By Reversed-Phase High Performance Liquid Chromatography, Valent U.S.A. Corporation, Project No. 10768.

860.1200  Directions for Use

Table 3.  Summary of Directions for Use of Clethodim.

Applic. Timing, Type, and Equip.	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 Limitations1, 2

Flax Seed

Apply by broadcast spray prior to bloom and mature foliage.	Prism® 0.94 EC (59639-78)

Select 2EC (59639-3)	Section B: 0.25

Label: 0.125	2	0.5

	Labels have 60

Section B has 20 	Label:

Prism® 0.94 EC:  Do not exceed 0.125 lbs ai/A per application.

Herb Subgroup 19A

Apply by broadcast spray to foliage.	Prism® 0.94 EC (59639-78)	Section B: 0.25

Label: 0.125	2	0.5

	Section B: 21

Label: 14

	Hops

Apply by broadcast spray to mature and fruiting cones.	Prism® 0.94 EC (59639-78)	Section B: 0.25

Label: 0.125	2	0.5

	21

	Asparagus

Apply by broadcast spray to emerging spears.	Prism® 0.94 EC (59639-78) Section B: 0.25

Label: 0.125	2	0.5

	1

		Sesame seed

Apply by broadcast spray to foliage.	Prism® 0.94 EC (59639-78)	Section B: 0.25

Label: 0.125	2	0.5

	14

	Leafy greens, Subgroup 4A

Apply by broadcast spray to foliage.	Prism® 0.94 EC (59639-78)	Section B: 0.25

Label: 0.125	2	0.5

	14

	Legume vegetable, Crop Group 6

Apply by broadcast spray to foliage.	Prism® 0.94 EC (59639-78)	0.25	2 0.5

	30 (longest PHI from study with dry pea.)

	Safflower

Apply by broadcast spray to foliage.	Prism® 0.94 EC (59639-78)	Section B:0.25

Label: 0.125	2	0.5

	Label has 14

Section B has 70

	1 All RACs have the following instructions:  Use a crop oil concentrate containing at least 15% emulsifier at 1% v/v to finished spray volume unless tank mix instructions indicate otherwise. Ground application use a minimum of 5 gals. of spray solution per acre. Air application use a minimum of 3 gals. of spray solution per acre. Do not apply more than 68 fl. oz of Prism® herbicide (0.5 lb ai) /A/season.

2 Application to Long Island, NY is restricted to 0.25 lb ai/A per season.

Conclusion:  All of the labeled directions for use differ from the corresponding proposed use pattern of Section B of the petition in the application rate and/or the length of the PHI (see TABLE 3 above).  The petitioner must submit revised labels to match the proposed use patterns of the Section Bs.  In addition, the petitioner did not request or submit data for tolerances on legume leaves/foliage.  Due to the lack of tolerances on these feed commodities, the label must include a statement restricting the grazing of fields or feeding of treated leaves to livestock.

860.1300 Nature of the Residue - Plants

PP#9F3743, MRID Nos. 41030137, 41030138, M. Nelson, 12/MAR/1990

Metabolism studies for clethodim in/on carrots, soybeans, and cotton have been conducted and reviewed.  The available metabolism studies on soybean, cotton, and carrots included soybean foliage, cotton foliage, and carrot leaves.  The metabolism in these crops and crop commodities is similar.  HED previously concluded that additional metabolism data may be required for future petitions on crops other than root crops and oil seed crops.  However, metabolism data for soybean foliage, cotton foliage, and carrot leaves can support the proposed uses for the requested RACs in these petitions.  The residues of concern are clethodim and its metabolites containing the 5-(2-ethylthiopropyl) cyclohexene-3-one and 5-(2-ethylthiopropyl) -5-hydroxycyclohexene -3-one moieties and their sulphoxides and sulphones.

860.1300 Nature of the Residue - Livestock

PP#9F3743, MRID Nos. 41030137, 41030138, M. Nelson, 12/MAR/1990

Metabolism studies of [propyl-1-14C]-clethodim in a lactating goat and laying hens have been previously reviewed.  The nature of the residue in ruminants and poultry is adequately understood for the purposes of the subject petition.  HED previously concluded that the residues of concern are clethodim and its metabolites containing the 2-cyclohexen-1-one moiety.  Of the submitted petitions, only safflower (meal) is a livestock feed commodity.

860.1340 Residue Analytical Methods

PP#: 9F3743, DP Num: 194694, F. Griffith, Jr., 28/SEP/1993

The analytical method used to assay clethodim residues in/on the requested RACs was RM-26B-3 (a modification of RM-26B-2) or RE 45601 (also adapted from Valent method RM-26B), which was validated for the analyses of residues of clethodim sulfoxide and its metabolite (5-hydroxy clethodim sulfone) in/on green onions, leaf lettuce, and cabbage.  Briefly, samples were extracted with methanol and then partitioned with dichloromethane.  After evaporation, the samples were oxidized with hydrogen peroxide, methylated with acidic methanol and then cleaned up on a silica gel 60 column and eluted with a hexane/acetone/methanol mixture.  Finally, the samples were analyzed for combined clethodim residues (DME and DME-OH) by GC/FPD-S.  In the analytical results, DME and DME-OH were reported as clethodim equivalents.  The concurrent recoveries and method validation recoveries of clethodim (DME and DME-OH) for the submitted trials were within the accepted range of 70-120%.  Exceptions were dried chives which were 65% (DME) and 60% (DME-OH), and DME-OH of succulent pea at 62%.  The residues of clethodim were stable, and the analytical method was shown to be reliable under the conditions of these studies.  The recoveries of clethodim residues in each matrix will not have an impact on the recommendations of this action.

860.1360 Multiresidue Methods

PP#9F3743, MRID Nos. 41030137, 41030138, M. Nelson, 12/MAR/1990

The petitioner has previously submitted data (1991; MRID No. 43166406, and 1992; MRID No. 43166407) describing the testing of clethodim and its metabolites through FDA Multiresidue Methods.  These data, which have been forwarded to FDA for review indicate that adequate recoveries of clethodim, clethodim sulfoxide, and 5-OH clethodim sulfone have been obtained under FDA’s multiresidue protocols.

860.1380 Storage Stability

45858501-01.der, L.Kutney, 09/NOV/2006

46258101.der, L. Kutney, 08/NOV/2006

46258102.der, L. Kutney, 02/NOV/2006

46434603.der, L. Kutney, 30/OCT/2006

46434606.der, L. Kutney, 01/NOV/2006

46434608.der, L. Kutney, 07/NOV/2006

46434609.der, L. Kutney, 31/OCT/2006

46434607.der, L. Kutney, 01/NOV/2006

46434605-01.der, L. Kutney, 07/NOV/2006

46434602.der, L. Kutney, 01/NOV/2006

46434601.der, L. Kutney, 07/NOV/2006

The storage stability of clethodim in the requested RACs is summarized in Table 4.  In each matrix, clethodim has been demonstrated to be stable over the period of time the study samples were harvested and analyzed.  There is no reason to believe that the residues of clethodim were unstable under the conditions of these studies or that storage stability will have any impact on the recommendations of this action.

TABLE 4.  Summary of Storage Conditions.

Matrix (RAC or Extract)	Storage Temp. ((C)	Actual Storage Duration

(days)	Storage Stability Recoveries (%)	Interval of Demonstrated

Storage Stability  (days)

	DME	DME-OH

	Vegetable, Leafy Greens Crop Subgroup 4A

 Lettuce (Head) (1997)	-25 to -15	748	Not

Conducted	98 - 112	732

Lettuce (Head) (2000)	-29 to -10	174	79-122	70-118	328

Flax Seed

Flax Seed	-21 ± 7	153	64 - 89	82 - 106	195 - 201

Herb Crop Subgroup 19A

Fresh basil leaves	-21 ± 7	406 (13.5 months))	75 – 88	93	385 (12.8 months)

Dry basil leaves	-21 ± 7	366 (12.2 months)	61 – 94	80 – 100	360 (12 months)

Fresh chive leaves	-21 ± 7	418	84	91	418

Dried chive leaves	-21 ± 7	369	76	86	374

Dried Hop Cones

Dried hop cones	< -21	319	78 - 86	81 - 86	336

Asparagus

Asparagus Spears	-21 ± 7	796 - 914	96	89	868 - 874

Sesame Seed

Sesame Seed	<0	692	74	76	674

Vegetable, Legume Crop Group 6 (except soybean)

Snap beans	<0	193	73	77	195-199

Dry Pea	-21 ± 7 	307	87-128	92-124	311

Lima bean	-21 ± 7	244	79-105	64-108	247-273

Succulent Pea	-21 ± 7	459	66 (80 adjusted)	58 (78 adjusted)	489

860.1400 Water, Fish, and Irrigated Crops

As no water, fish, or irrigated crops issues are associated with the use of clethodim on the subject RACs, this guideline requirement is not relevant to the current petitions.

860.1460 Food Handling

As there are no food handling uses for clethodim, this guideline requirement is not relevant to the current petitions.

860.1480 Meat, Milk, Poultry, and Eggs

No feeding studies were submitted with this petition. Feeding studies were previously submitted and reviewed (PP#9F3743, MRIDs 41030221 & 41030222, M. Nelson, 03/12/1990). Permanent tolerances for livestock and poultry have been established for the combined residues of clethodim[(E)-(±)-2-[1-[[(3-chloro-2-propenyl)oxy]imino]propyl]-5-[2-(e thylthio)propyl]-3-hydroxy-2-cyclohexen-1-one] and its metabolites containing the 2-cyclohexen-1-one moiety (40 CFR §180.458).

Dairy Cattle

The petitioner conducted a feeding study with lactating dairy cows (MRID 41030222). Fourteen Holstein cows were used for the study (randomly divided into one control group of two cows and three test groups of four cows each).  Following an acclimation period of 7 days, each cow in the test groups was given an oral dose of a 5:95 mixture of clethodim:clethodim sulfoxide contained in a gelatin capsule, once daily for 28 consecutive days.  The dosing levels were 10 ppm, 30 ppm, and 100 ppm equivalency in the diet for the three test groups based on the highest daily food consumption, determined during the acclimation period: 85 lbs/cow/day.  These dosing levels would be equivalent to 2.8x, 8.3x and 27.8x the dietary burden for beef cattle, and 2.6x, 7.9x and 26.3x the dietary burden for dairy cattle (Based on a reasonable diet composed of feed items likely to be fed to cattle, with and without tolerances.  See Attachments 1 and 2.).

Three cows from each dose level and one control cow were sacrificed on test day 29, within 24 hours of the last dose; and the remaining cow in each group on day 31, after 2 days withdrawal.  Samples of liver, kidney, composite muscle, and composite fat (peritoneal and subcutaneous) were collected from each carcass for residue analysis.

Milk samples, consisting of' equal parts of morning and evening milkings for a given day, were collected from each cow on days -1, 1, 2, 4, 7, 12, 16, 20, 24, 28, 29, 30, and 31.

All tissue and milk samples were maintained under frozen storage (-20(C) until analysis for total clethodim residues (measured as DME, DME-OH, and S-DME expressed as clethodim equivalents) by a modified version of RM-26A (adapted for milk and bovine tissues). The results of residue analysis of bovine tissues and milk are summarized in Table 5.

	Table 5. Clethodim Residues in Dairy Cows

Feeding Levels

Chemicals

Milk

Liver

Kidney

Muscle

Fat

10 ppm

DME

ND

0.06

0.05

ND

ND

DME-OH

ND

ND

ND

ND

ND

S-MEDME

ND

ND

ND

ND

ND

30 ppm

DME

0.03

0.12

0.17

ND

0.05

DME-OH

ND

ND

ND

ND

ND

S-MEDME

ND

ND

ND

ND

ND

100 ppm

DME

0.08

0.45

0.54

0.07

0.15

DME-OH

ND

ND

ND

ND

ND

S-MEDME

0.03

0.09

0.08

ND

ND

ND = Not Detected (<O.0125 ppm for milk and <0.05 ppm for tissues)

DME residues were found in liver and kidney at all feeding levels; in milk and fat, at the 30 and 100 ppm feeding levels; and, in muscle, at the l00 ppm level only.  S-MEDME was found in milk, liver, and kidney at the 100 ppm level.  DME-OH was not found in milk or any tissue at any feeding level.  Residues in milk plateaued on test days 1 or 2.

No detectable residues of DME, DME-OH, or S-MEDME were reported in any control milk (<O.0125 ppm) or bovine tissue (<O.05 ppm) samples.

Composite whole milk samples collected on test days 25, 26, and 27 from the control group and the 100 ppm dose level group were processed to obtain skim milk (nonfat solids), cream (fat solids), pasteurized milk, and acid whey (lactose).  Analysis for total clethodim residues (DME + DME-OH + S-MEDME) was performed on these processing fractions. Based on the recommended tolerances in this submission and established tolerances, the maximum theoretical residues in diets of beef and dairy cattle were calculated and the current theoretical maximum dietary burdens were determined (see Table 6).

TABLE 6. Theoretical dietary burden of clethodim from various feed commodities for beef and dairy cattle

Feed Commodity

Tolerance or Proposed Tolerance

(ppm)

% Dry Matter

Beef Cattle

Dairy Cattle

% of Diet

Burden (ppm)

% of Diet

Burden

(ppm)

Alfalfa, forage

6.0

35

20

3.4

Alfalfa, hay

10.0

89

15

1.7

Grass/nongrass/cereal grain, forage/silage/hay	0

25

	Beet, sugar, molasses	1.0	75	5	0.07	5	0.07

Potato, processed waste	0.5	20	30	0.75	10	0.25

Corn, field, grain/other grains/grain milled byproducts	0

40

30

	Cotton, undelinted seed	1.0	88

	10	0.11

Safflower/sunflower, meal	10.0	88	10	1.1

Total

100

3.6

100

3.8

HED Comments/Conclusions:

The established tolerances on meat and milk are adequate to cover the proposed uses. According to Table 1 of OPPTS 860.1000 and the recommended and established tolerances for clethodim, the maximum theoretical residues in the diets of beef cattle and dairy cattle were calculated; the theoretical maximum dietary burdens were determined to be 3.6 ppm for beef and 3.8 ppm for dairy cattle.  Based on the previous feeding studies, the secondary residues in meat and milk will not exceed the established tolerances.  This does not include foliage from legume vegetables, thus the label must have a restriction on grazing of treated fields and the feeding of treated foliage to livestock.

Poultry

The petitioner conducted a feeding study with laying hens (MRID 41030221).  Young laying hens were randomly assigned (20 hens each) to one of three test groups or the control group.  Following an acclimation period of 35 days, each hen in the test groups received an oral dose of a 5:95 mixture of clethodim:clethodim sulfoxide (purity, >98.5%) contained in a gelatin capsule, once daily for 28 consecutive days. Controls received gelatin capsules containing only the carrier (corn oil and evaporated acetone).  Hens received poultry mash and water ad libitum throughout the dosing period.

The dose levels for the three test groups were 10 ppm, 30 ppm, and l00 ppm equivalency in the diet based on the highest daily food consumption, determined during the 35 day acclimation period: 151.3 grams/hen/day.  These dosing levels would be equivalent to 3.3x, 10x and 33.3x the theoretical maxium dietary burden for poultry (Based on a reasonable diet.  See Attachments 1 and 2.).

Egg samples were retained and pooled by dose group for days -1, 1, 2, 4, 7, 14, 21, 28, 29, and 30.  On day 29, ten hens from each group were randomly selected for sacrifice; all remaining hens were sacrificed on day 31.  Thigh and breast muscle, liver, gizzard, and subcutaneous and abdominal fat were collected for residue analysis from each hen, pooled by tissue and test group, and 2-3 subportions of each were taken for analysis by method RM-26A (adapted for eggs and chicken tissues).  The results of the residue analysis are summarized in Table 7.

TABLE 7. Clethodim Residues in Laying Hens

Feeding Levels

Chemicals

Eggs

Fat

Gizzard

Liver

Muscle

10 ppm

DME a

NDc

ND

ND

ND

ND

DME-OH b

ND

ND

ND

ND

ND

S-MEDME c

ND

ND

ND

ND

ND

30 ppm

DME

0.05-0.09

ND

ND

ND

ND

DME-OH

ND

ND

ND

ND

ND

S-MEDME

ND

ND

ND

ND

ND

100 ppm

DME

0.14-0.24

ND

ND

0.06

ND

DME-OH

ND

ND

ND

ND

ND

S-MEDME

ND

ND

ND

ND

ND

a	Expressed  as clethodim (C)

b	Expressed  as 5-OH clethodim sulfoxide (5-0H-SO 2)

c	Expressed  as S-methyl clethodim sulfone (SMSO)

ND = no detectable residue (<O.05 ppm)

No detectable residues (0.05 ppm) of DME, DME-OH, or S-MEDME were found in any control samples of eggs or poultry tissues. No residues were detected (<O.05 ppm) in any of the fat, gizzard, or muscle samples, even at the 100 ppm dose level.

Clethodim (DME) of 0.06 ppm was found in only one liver sample (day 29), which was from the 100 ppm dose level.  No DME-OH and S-MEDME were detected (<0.05 ppm) in any of the liver samples.

No detectable residues (<0.05 ppm) of DME, DME-OH, or S-MEDME were reported in any control egg or poultry tissue samples.  No detectable residues (<0.05 ppm) of clethodim were found in eggs from the 10 ppm dose level.  Clethodim residues were found in eggs from both the 30 ppm (0.05-0.09 ppm) and 100 ppm (0.14- 0.24 ppm) dose levels; these residues declined to <0.05 ppm by day 29. No DME-OH and S-MEDME were detected (<0.05 ppm) in any of the egg samples.

Based on the recommended tolerances in this submission and the established tolerances, the maximum theoretical residues in poultry were calculated and a reasonable theoretical dietary burden was determined (see Table 8).

TABLE 8. Theoretical dietary burden of clethodim from various feed commodities for poultry.

Feed Commodity

Tolerance or Proposed Tolerance

(ppm)

Poultry

% of Diet

Burden

(ppm)

Corn, field, grain/other grains/grain milled byproducts	0	70

Safflower/sunflower, meal

10.0

10

1.0

Soybean, seed

10.0

20

2.0

Total

100

3.0

HED Comments/Conclusion:

The established tolerances on poultry and eggs are adequate to cover the proposed uses.  According to Table 1 of OPPTS 860.1000 and the recommended and established tolerances for clethodim, the maximum theoretical residues in a reasonable diet of poultry were calculated; the theoretical maximum dietary burden was determined to be 3.0 ppm for poultry.  Based on the previous poultry feeding studies, secondary residues in poultry and eggs will not exceed the established tolerances.

Swine

The tolerances set for swine are based upon the cattle feeding study and a reasonable diet as described in Attachment 2.  Since legume foliage is not a swine feed item, and the requested RACs are not fed to swine when using a reasonable diet, secondary residues in swine will not exceed the established tolerances.

860.1500 Crop Field Trials

45858501-01.der, L.Kutney, 09/NOV/2006

46258101.der, L. Kutney, 08/NOV/2006

46258102.der, L. Kutney, 02/NOV/2006

46434603.der, L. Kutney, 30/OCT/2006

46434606.der, L. Kutney, 01/NOV/2006

46434608.der, L. Kutney, 07/NOV/2006

46434609.der, L. Kutney, 31/OCT/2006

46434607.der, L. Kutney, 01/NOV/2006

46434605-01.der, L. Kutney, 07/NOV/2006

46434602.der, L. Kutney, 01/NOV/2006

46434601.der, L. Kutney, 07/NOV/2006

The petitioner has requested a tolerance for safflower, meal at 10 ppm and safflower, seed at 5.0 ppm based on already established tolerances on sunflower, meal and sunflower, seed.  Due to the similarity of the two crops, the Agency is willing to give a direct translation of the sunflower tolerances to the safflower requests.  This translation of tolerance also includes the translation of usage patterns.  The petitioner must submit a revised label for the use of safflower to match that of sunflower.  If the petitioner would like to have lower tolerances or different use patterns, data supporting the lower tolerances and use patterns would need to be submitted to the Agency.

Table 9 summarizes the residues of clethodim on the RACs requested with these petitions from the submitted crop field trials.

Table 9.  Summary of Residues from the Crop Field Trials with Clethodim.

Crop Matrix	Total Applic. Rate

(lb ai/A)	PHI (days)	Residues (ppm)

	Mean	Std. Dev.	HAFT	Min.	Max.

Flax (proposed use = 0.50 lb ai/A total application rate, 12-15-day PHI)

Flax Seed	0.52	12-18	0.29	0.08	0.38	0.18	0.41

Herb Crop Subgroup 19A (proposed use = 0.50 lb ai/A total application rate, 20-22 day PHI)

Basil, fresh	0.48	20-21	1.27	0.07	1.27	0.92	1.32

Basil, dried	0.48	20-21	---	---	---	6.32	6.32

Chives, fresh	0.48	20-22	0.81	0.72	1.90	0.24	2.16

Chives, dried	0.48	20	0.24	0	0.24	0.24	0.24

Hops, Dried Cones (proposed use = 0.50  lb ai/A total application rate, 20-21 day PHI)

Hops, Dried Cones	0.50	20-21	<0.50	0	<0.50	<0.50	<0.50

Asparagus (proposed use = 0.50  lb ai/A total application rate, 1 day PHI)

Asparagus Spears	0.50	1	0.66	0.18	0.86	0.37	0.99

Sesame (proposed use = 0.50  lb ai/A total application rate, 13-15 day PHI)

Sesame seed	0.50	13-15	0.23	0.032	0.23	0.19	0.28

Crop Subgroup 4A (proposed use = 0.50  lb ai/A total application rate, 13-15 day PHI)

Lettuce with wrapper leaves intact	0.50	13-15	<0.30	<0.11	<0.48	<0.22 <0.56

Lettuce with wrapper leaves removed	0.50	13-15	<0.27	<0.06	<0.34	<0.18 <0.34

Crop Group 6 (proposed use = 0.50  lb ai/A total application rate, 13-15 day PHI)

Snap beans	0.50	20-22	0.25	0.11	0.44	<0.18	0.46

Dry pea	0.50	29 – 31	0.60	0.36	1.16	<0.18	1.24

Lima bean	0.50	20 - 22	0.41	0.16	0.62	<0.18	0.65

Shelled pea	0.50	16-21	1.76	0.43	2.32	1.24	2.55

Edible-podded pea	0.50	20-22	1.30	0.46	1.74	<0.58	1.84

Flax, Seed

A tolerance currently exists for flax, seed and flax, meal.  The petitioner previously submitted field trial data to support a tolerance on flax, seed with an Agency recommended use pattern of one post-emergent application at a rate of 0.08 lb ai/A with a 75 day PHI (PP# 0E006202, DP Num: 271248, M. Xue, 14/JUN/2001).  However, no processing data was submitted for flax.  In the absence of processing data, data from canola was translated to flax to fulfill the data requirements (PP# 0E006202, DP Num: 271248, M. Xue, 14/JUN/2001).  A tolerance for flax, meal at 1.0 ppm was established for flax based on this translated canola data.  To remove this tolerance or decrease this tolerance on flax, meal, the petitioner needed to submit flax processing studies.  To support the new use pattern of clethodim on flax, seed,   SEQ CHAPTER \h \r 1 IR-4 has submitted field trial residue data for clethodim on flax (PP# 3E6555).  Six field trials were conducted in the 2000 growing season in North Dakota (3 trials, EPA Regions 5 and 7) and South Dakota (3 trials, EPA Region 5).  All field trial sites consisted of one untreated control plot and one treated plot.  Two broadcast spray applications of clethodim (Prism® 0.94 EC) were applied at ~ 0.25 lb ai/A (~ 0.50 lb ai/A per season) with 13-14 days between applications, and then harvested with a pre-harvest interval of 12-18 days.  Field treated samples of flax seeds were stored up to 153 days.

Two untreated (control) and two treated samples were taken from each field trial, to ensure a representative sample.  At the ND13, ND14 & ND15 trials, the plots (except the plot edges) were combined and the seeds were collected.  At the ND13 and ND14 trials, the seeds were cleaned with hand sieves.  At the SD02, SD03 & SD04 trials, the flax was pulled randomly across the plot avoiding plot edges.  The flax was then threshed and the seed collected.

The residues of clethodim in flax seeds were analyzed via GC/FPD-S as DME and

DME-OH, reported as clethodim equivalents.  The analytical method used in this study was adequately validated in conjunction with the analysis of field trial samples.  The limit of detection (LOD) and LOQ could not be calculated for flax seed.  The lowest limit of method validation (LLMV) was 0.078 ppm for DME and 0.076 ppm for DME-OH.

Concurrent recoveries were generally acceptable with a few exceptions.  Recoveries for flax seed were 67-128% for DME and 74-129% for DME-OH.  Total clethodim residues (from DME and DME-OH) ranged from an average of 0.18-0.41 ppm on treated flax seed at PHIs of 12-18 days.  Adequate storage stability data are available.  Storage stability recoveries were 64-89% DME and 82-106% for DME-OH in flax seed.  Residues of clethodim (from DME) ranged from <0.095-0.32 ppm and there were no detectable residues of clethodim (from DME-OH) observed in flax seed.

Conclusions:  The field trials were acceptable and adequately supported.  However, using the MRL calculator a tolerance of 0.6 ppm is recommended for the commodity flax seed.  The calculated tolerance of 0.6 ppm is different from the tolerance level (0.5 ppm) proposed by the petitioner.  A revised Section F is required.  The MRL Calculations can be found in the appendix.

Herb Crop Subgroup 19A

To support the use of clethodim on Herb Crop Subgroup 19A, crop field trial studies were submitted for representative crops, basil and chives (PP# 4E6836).  The studies provide residues for both fresh and dried samples of each RAC.

Basil

  SEQ CHAPTER \h \r 1 IR-4 has submitted crop field trial data for clethodim on basil (PP# 4E6836).  The submitted data were obtained from field trials conducted in New York, New Jersey, and California (EPA Regions 1, 2, and 10, respectively), one trial at each site.  All field trial sites consisted of one untreated control plot and one treated plot except for the California site (05759-CA*42), which had two control and two treated plots for collection of fresh and dry basil.  At each trial location, clethodim was foliarly applied as Prism® 0.94 EC, containing 12.6% clethodim.  This formulation was applied 2 times at the application rate of ~ 0.25 lb ai/A (0.50 lb ai/A per season) with 13-15 days between applications.

Basil leaves (minimum of 2 lb per sample) were harvested randomly across the plots at pre-harvest intervals of 20 to 21 days.  Fresh samples were placed in a freezer within 3 hours of harvest.  In the California field trial, additional control and treated samples were collected and subsequently dried following commercial procedures to yield 2 lb samples.  Before the analysis, all samples were stored and shipped frozen.  In fresh and dried basil leaves, clethodim residues were analyzed via GC/FPD-S as DME and DME-OH, reported as clethodim equivalents.  The analytical method used in this study was adequately validated in conjunction with the analysis of field trial samples.  The estimated LOD was reported to be 0.050 ppm for both DME and DME-OH.  The LOQ was reported to be 0.10 ppm for DME and DME-OH.

Most recoveries were within the acceptable range (70-120%), with the lowest and highest recovery levels at 62% and 140%, respectively.  Storage stability data show that the residues were stable for the duration of sample storage.  In fresh basil, DME and DME-OH residues ranged from 0.80-1.2 ppm and from <0.12-0.12 ppm, respectively.  In dried basil, residue concentrations were 6.0 ppm DME and 0.32 ppm DME-OH.

Chives

  SEQ CHAPTER \h \r 1 IR-4 has submitted crop field trial data for clethodim on chives (PP# 4E6836).  The submitted data were obtained from field trials conducted in New Jersey (1 trial) and California (3 trials) (EPA Regions 2, and 10, respectively) during the 1997 growing season.  All field trial sites consisted of one untreated (control) plot and one treated plot except for the California site, 06246-CA*39, which had two control and two treated plots for fresh and dry samples.  At each trial location, clethodim was foliarly applied as Prism® 0.94 EC, containing 12.6% clethodim.  This formulation was applied two times at approximately 0.25 lb ai/A (~0.50 lb ai/A per season) with 14-16 days between applications.

Chive leaves (minimum of 2 lb per sample) were harvested randomly across the plots at pre-harvest intervals of 20-22 days.  Fresh samples were placed in a freezer within 3 hours of harvest. In the California field trial, additional control and treated samples were collected and subsequently dried following commercial procedures to yield 2 lb samples.  Before the analysis, all samples were stored and shipped frozen.  Clethodim residues were analyzed via GC/FPD-S, as DME and DME-OH, reported as clethodim equivalents.  The analytical method used in this study was adequately validated in conjunction with the analysis of field trial samples.  The estimated LOD was reported to be 0.050 ppm for both DME and DME-OH.  The LOQ was reported to be 0.10 ppm for DME and DME-OH.

Most recoveries were within the acceptable range (70-120%), with the lowest and highest recovery levels at 59% and 120%, respectively.  Storage stability data show that the residues were stable for the duration of sample storage.  In fresh chive leaves, DME and DME-OH residues ranged from <0.12-2.0 ppm and from <0.12-0.16 ppm, respectively.  In dried chive leaves, DME and DME-OH residue concentrations were both <0.12 ppm.

Conclusions:  Since a tolerance for Herb crop subgroup 19A is sought and not individual tolerances, ARIA recommends for a conservative tolerance of 12.0 ppm to cover all categories (fresh and dried) of this crop group.  This tolerance is based on the drying factor of 9 (e-mail communication, B. Schneider, 10/JAN/2007) for basil multiplied by the maximum residue reported in the fresh basil trials, rounded up to the nearest whole number (9 X 1.27 = 11.43).  A revised Section F must be submitted by the petitioner changing the requested tolerance of 10.0 ppm to 12.0 ppm.

Hops

To support the use of clethodim on hops,   SEQ CHAPTER \h \r 1 IR-4 has submitted field trial data for clethodim on hops (PP#: 5E6977).  Three field trials were conducted in   SEQ CHAPTER \h \r 1 Idaho (1 trial, EPA Region 11), Washington (1 trial, EPA Region 11) and Oregon (1 trial, EPA Region 12) during the 2001 growing season.  All field trial sites consisted of one untreated control plot and one treated plot.  Two post-emergence spray applications of clethodim (Prism® 0.94 EC herbicide) were made to both sides of the hop row on the yard floor at 0.25 lb ai/A (0.50 lb ai/A per season) with 7-14 days between applications.  Hops were harvested at pre-harvest intervals (PHIs) of 20-21 days, dried within a day of harvest and stored frozen until analysis for up to 319 days from collection to analysis.

Residues were analyzed via GC/FPD as DME and DME-OH, reported as clethodim equivalents.  The analytical method used in this study was adequately validated in conjunction with the analysis of field trial samples.  In all samples, DME and DME-OH were each <0.25 ppm on hops.  Total combined residues of clethodim on hops were all <0.50 ppm at PHIs of 20-21 days.

Overall recoveries were adequate, ranging from 74-121%.  Storage stability data were obtained by fortifying untreated hops with the equivalent of 0.78 and 0.76 ppm of DME/DME-OH, respectively.  The samples were stored at <-20°C for up to 336 days.  Residues of clethodim were determined to be adequately stable to support this study.  The LOD was reported to be 10% below the lowest linearity standard, 0.25 ppm for both DME and DME-OH.  The LOQ is 0.25 ppm for DME and 0.25 ppm for DME-OH.

Conclusions:  It was not necessary to use the MRL Calculator on this crop since all of the residues were at or below the LOQ.  ARIA recommends for a tolerance of 0.5 ppm (LOQ) for hops, dried cones.

Asparagus

To support the use of clethodim on asparagus,   SEQ CHAPTER \h \r 1 IR-4 has submitted field trial data for clethodim on asparagus (PP#: 5E6977).  Seven field trials were conducted in the 1997 season, from New Jersey (1 trial, EPA Region 2), Michigan (2 trials, EPA Region 5), Washington (1 trial, EPA Region 11) and California (3 trials, EPA Region 10).  All field trial sites consisted of one untreated control plot and one treated plot.  Two broadcast applications of clethodim were performed at 0.25 lb ai/A (0.50 lb ai/A per season), with 13-14 days between applications.  Asparagus spears were harvested at pre-harvest intervals of 1, 2 and 3 days and stored frozen until analysis.

Clethodim residues were analyzed via GC/FPD-S, as DME and DME-OH, reported as clethodim equivalents.  The analytical method used in this study was adequately validated in conjunction with the analysis of field trial samples.  DME residues ranged from <0.095-1.3 ppm and DME-OH residues ranged from <0.088-0.25 ppm in/on asparagus.  Total combined residues of clethodim on treated asparagus varied from 0.37-0.99 ppm at a PHI of 1 day, 0.18-1.39 ppm at a PHI of 2 days, and 0.18-0.84 ppm at a PHI of 3 days.  The highest average field trial residue for clethodim was 0.86 ppm at the 1-day PHI, 0.78 ppm at the 2-day PHI and 0.51 ppm at the 3-day PHI.  Clethodim residues averaged 0.66 ppm at the 1-day PHI, 0.50 ppm at the 2-day PHI and 0.35 ppm at the 3-day PHI.

Recoveries were acceptable at all fortifications.  Concurrent with storage stability analysis, untreated asparagus spears were fortified an equivalent of 1.6 ppm of DME and 1.5 ppm of DME-OH.  Residues of clethodim were determined to be adequately stable for 868-874 days and support the study.  The calculated LODs were 0.037 ppm for DME and 0.025 ppm for DME-OH, and the calculated LOQs were 0.110 ppm for DME and 0.075 ppm for DME-OH.

Conclusions:  Using the supplied residue data and the MRL Calculator, a tolerance level of 1.7 ppm is recommended for the commodity asparagus.  The MRL calculations can be found in the appendix for each of the PHIs (1,2, or 3 days) tested in the study.  The 2 day PHI gave the highest recommended tolerance at 1.7 ppm.  ARIA believes the most conservative risk will be based on using the highest tolerance recommendation, even though the requested PHI is 1 day.  The petitioner must submit a revised Section F to the Agency changing the proposed tolerance from 2.0 ppm to 1.7 ppm.

Sesame

To support the use of clethodim on sesame, IR-4 has submitted field trial data for clethodim on sesame (PP#: 4F6895).  Four field trials were conducted in Texas (EPA Region 6) during the 2000 growing season.  The number and locations of field trials are in accordance with OPPTS Guideline 860.1500.  Clethodim was applied twice foliarly at 0.25 lb ai/A to sesame, at 15-day intervals, using the formulation Prism® 0.94 EC containing 12.6% clethodim.  The test substance was mixed with water and a crop oil concentrate (1% v/v).  Sesame stalks were harvested 13-15 days following the last application.

Clethodim residues were analyzed using the Cornell analytical Laboratories Working Method, “Residue Analysis of RE 45601 (Clethodim) and its Metabolites by GC/FPD-Sulfur Detector, Version #6, 6A, and 6B,  Sesame Seed, Oil, and Meal,” with minor modifications.  The analytical method used in this study was adequately validated in conjunction with the analysis of field trial samples.  Clethodim residues in seed ranged from 0.15-0.18 ppm DME and <0.088-0.095 ppm

DME-OH.  In this study, the LLMV for combined clethodim residues were 0.183 ppm for sesame seed.  The LOQs were determined to be 0.062 ppm for DME and 0.091 ppm for DME-OH for sesame seed.  The LODs were determined to be 0.02 ppm for DME and 0.03 ppm for DME-OH for sesame seed.  The maximum storage interval for field treated samples was 692 days for seed.  Freezer storage stability data were adequate and accounted for >95% of the maximum storage interval of field trials.  Clethodim residues in seed contained 0.10-0.18 ppm DME and <0.088-0.095 ppm DME-OH.

Conclusions:  Using the supplied residue data and the MRL Calculator, a tolerance level of 0.35 ppm is recommended for the commodity sesame, seed.  The MRL calculations can be found in the appendix.  The petitioner must submit a revised Section F to change the requested tolerance of 0.30 ppm to 0.35 ppm.

Vegetable, Leafy Greens Crop Subgroup 4A

Tolerances for spinach and leaf lettuce were previously established at 2.0 ppm.

Lettuce, Head

IR-4 has submitted field trial data for clethodim on lettuce (head) (PP#: 5E6978).  Three field trials were conducted in Florida, Ohio and New York (EPA Regions 1, 3, and 5, respectively) during the 1997 growing season.  Also, five California trials (EPA Region 10) and one Oregon trial (EPA Region 12) were conducted during the 2000 growing season.  The number and locations of field trials are in accordance with OPPTS Guideline 860.1500.  At each trial location, Prism® 0.94 EC, a 12.6% emulsifiable-concentrate (EC) formulation of clethodim, was foliarly applied to lettuce twice at approximately 0.25 lb ai/A (0.50 lb ai/A per season) with 13 to 15 days between applications.  The test substance was mixed with water and a crop oil concentrate (1% v/v).  Lettuce with and without wrapper leaves was harvested 13 to 15 days following the last application.

Samples were analyzed for clethodim residues as DME and DME-OH using the Working Method derived from “Determination of Clethodim Residues in Crops, Chicken and Beef Tissues, Milk and Eggs,” with minor modifications.  This analytical method is acceptable as a data-gathering method.  The maximum storage interval was 748 days for field treated lettuce samples in the 1997 study.  Also, the maximum storage interval was 174 days for field treated lettuce samples in the 2000 study.  Storage stability data demonstrate that DME and DME-OH residues were stable for the duration of sample storage in the 2000 study, but only for DME-OH in the 1997 study.  Storage stability was not reported for DME in the 1997 study.  In the 1997 study, the LOQs for both DME and DME-OH were 0.10 ppm and no LODs were reported.  In the 2000 study, the LOQs were 0.081 ppm for DME and at 0.095 ppm for DME-OH and the LODs were 0.03 ppm for both residues.  In head lettuce with wrapper leaves, the concentration of DME (reported as clethodim equivalents) ranged from 0.12 to 0.46 ppm.  In head lettuce without wrapper leaves, DME concentrations (reported as clethodim equivalents) ranged from 0.08 ppm to 0.24 ppm.  In all samples, DME-OH concentrations were <0.10 ppm.

Conclusions:  Using the supplied residue data and the MRL Calculator, a tolerance level of 0.80 ppm is recommended for the commodity head lettuce.  The MRL calculations can be found in the appendix.  Based on the previously established tolerances on members of the Crop Subgroup 4A, spinach and leaf lettuce, of 2.0 ppm and the data submitted for lettuce, head (0.80 ppm), ARIA recommends for a tolerance of 2.0 ppm be set for the vegetable, leafy greens Crop Subgroup 4A.

Crop Group 6 (Legume Vegetables)

To support the use of clethodim on Crop Group 6 (legume vegetables) (except soybean) RACs, crop field trial studies were submitted for representative crops, snap beans, dry pea, lima bean and succulent pea (PP#: 4F6895).  A tolerance for dry beans has previously been established at 2.5 ppm.

Snap Beans

IR-4 has submitted field trial data for clethodim on snap beans (PP#: 4F6895).  Eight field trials were conducted in New York (EPA Region 1), North Carolina (EPA Region 2), Florida (EPA Region 3), Michigan (EPA Region 5), Wisconsin (EPA Region 5), California (EPA Region 10), Washington (EPA Region 11) and Ohio (EPA Region 5) during the 2001 growing season, one trial was conducted in each state.  The number and locations of field trials are in accordance with OPPTS Guideline 860.1500 for crop group tolerances.  At each trial location, Prism® 0.94 EC, a 12.6% emulsifiable-concentrate formulation of clethodim, was foliarly applied twice at approximately 0.25 lb ai/A (0.50 lb ai/A per season).  At the New York, North Carolina and Ohio trials, three applications were made, for a total of 0.75 lb ai/A.  The test substance was mixed with water and a crop oil concentrate (1% v/v).  The applications were made at 12-20-day intervals and mature snap beans were collected 20-22 days following the final application.

Samples were analyzed for clethodim residues as DME and DME-OH using the Cornell Analytical Laboratories Working Method, “Residue Analysis of RE 45601 (Clethodim) and Its Metabolites by GC/FPD-Sulfur Detector, Version #8 (adapted from Valent U.S.A. Corporation Method RM-26B-3),” with minor modifications.  This analytical method is acceptable as a data-gathering method.  The LLMVs were 0.095 ppm for DME and 0.088 ppm for DME-OH. The LOQs for the method were estimated to be 0.054 ppm for DME and 0.073 ppm for DME-OH.  The LODs wee 0.02 ppm for DME and 0.02 ppm for DME-OH.  The maximum storage interval for field treated samples in this study was 193 days.  Frozen storage stability studies indicate clethodim and its metabolites are stable for the duration of sample storage.  The analytical results of the study show that clethodim residues ranged from <0.095-0.32 ppm DME and <0.088-0.32 ppm DME-OH in snap beans.  Total clethodim residues ranged from <0.18-0.64 ppm clethodim in snap beans.

Using the supplied residue data and the MRL Calculator, a tolerance level of 0.90 ppm is recommended for the commodity snap beans.  The MRL calculations can be found in the appendix.

Dry Pea

IR-4 has submitted field trial data for clethodim on dry pea (PP#: 4F6895).  Six field trials were conducted, in Nebraska (EPA Region 7, two trials), South Dakota (EPA Region 7, one trial), and Washington (EPA Region 11, three trials) during the 2001 growing season.  The number and locations of field trials are in accordance with OPPTS Guideline 860.1500.  At each trial location, Prism® 0.94 EC, a 12.6% emulsifiable-concentrate formulation of clethodim, was foliarly applied twice at 0.25 lb ai/A (0.50 lb ai/A per season).  The test substance was mixed with water and a crop oil concentrate.  Clethodim was applied at 13-16 day intervals and  mature pea plants were harvested 29-31 days after the final application.  Pea plants were left in the field to dry for one to two weeks and then collected.

The pea samples were analyzed for clethodim residues as DME and DME-OH using the Cornell Analytical Laboratories Working Method, “Residue Analysis of RE 45601 (Clethodim) and Its Metabolites by GC/FPD-Sulfur Detector, Version #10” (adapted from Valent U.S.A. Corporation Method RM-26B-3), with minor modifications.  This analytical method is acceptable as a data-gathering method.  The LLMVs in this study were 0.095 ppm for DME and 0.088 ppm for DME-OH.  The LOQs for the method were calculated to be 0.080 ppm for DME and 0.068 for DME-OH.  The LODs were calculated to 0.03 ppm for DME and 0.02 ppm for DME-OH.  The maximum storage interval for field treated samples in this study was 307 days.  Freezer storage stability data were provided and show that clethodim and its metabolites are stable for the duration of storage.  The analytical results of the study show that clethodim residues ranged from <0.095-0.82 ppm DME and <0.088-0.42 ppm DME-OH in dry peas.  The range of total clethodim residues in treated dry pea was <0.18-1.24 ppm clethodim.

Using the supplied residue data and the MRL Calculator, a tolerance level of 2.5 ppm is recommended for the commodity dry peas.  The MRL calculations can be found in the appendix.

Lima Bean

IR-4 has submitted field trial data for clethodim on lima beans (PP#: 4F6895).  Eight field trials were conducted in New Jersey (EPA Region 2, one trial), North Carolina (EPA Region 2, two trials), Wisconsin (EPA Region 5, one trial), California (EPA Region 10, two trials), Washington (EPA Region 11, one trial) and Georgia (EPA Region 2, one trial) during the 2001 growing season.  The number and locations of field trials are in accordance with OPPTS Guideline 860.1500.  At each trial location, Prism® 0.94 EC, a 12.6% emulsifiable-concentrate (EC) formulation of clethodim was applied twice at approximately 0.25 lb ai/A (0.50 lb ai/A per season).  At the North Carolina (01-NC04) trial, a third application (for a total of approximately 0.75 lb ai/A) was made.  The test substance was mixed with water and a crop oil concentrate (1% v/v).  The foliar applications were made at 13-18 day intervals and mature snap beans were collected 20-22 days following the final application.

Lima bean samples were analyzed for clethodim residues as dimethyl ester sulfone (DME) and

5-hydroxy dimethyl ester sulfone (DME-OH) using the Cornell Analytical Laboratories Working Method, “Residue Analysis of RE 45601 (Clethodim) and Its Metabolites by GC/FPD-Sulfur Detector, Version #9” (adapted from Valent U.S.A. Corporation Method RM-26B-3),” with minor modifications.  This analytical method is acceptable as a data-gathering method.  The LLMVs were 0.095 ppm for DME and 0.088 ppm for DME-OH.  The LOQs for the method wer determined to be 0.037 ppm DME and 0.073 ppm DME-OH.  The LODs were determined to be 0.01 ppm for DME and 0.02 ppm for DME-OH.  The maximum storage interval for field treated samples in this study was 244 days.  Freezer storage stability data were provided and show that clethodim and its metabolite are stable for the duration of sample storage.  Clethodim residues ranged from <0.095-0.55 ppm DME and <0.088-0.10 ppm DME-OH in lima beans.  The range of total clethodim residues was <0.18-0.65 ppm clethodim.

Using the supplied residue data and the MRL Calculator, a tolerance level of 1.1 ppm is recommended for the commodity lima beans.  The MRL calculations can be found in the appendix.

Succulent Pea

IR-4 has submitted field trial data for clethodim on succulent pea (PP#: 4F6895).  Eight field trials (four succulent shelled pea and four edible-podded pea) were conducted in Wisconsin (EPA Region 5, three trials), Michigan (EPA Region 5, one trial), California (EPA Region 10, one trial), Washington (EPA Region 11, one trial), Idaho (EPA Region 11, one trial), and Oregon (EPA Region 12, three trials) in the 2002 growing season.  The number and locations of field trials are not in strict accordance with OPPTS Guideline 860.1500 as they pertain to crop group tolerances.  At each trial location, Prism® 0.94 EC, a 12.6% emulsifiable-concentrate (EC) formulation of clethodim was foliarly applied twice at approximately 0.25 lb ai/A (0.50 lb ai/A per season) with 12-14 days between applications.  The test substance was mixed with water and a crop oil concentrate.  Mature pea plants were harvested 20-22 days following the final application with the exception of the 01-WA*04 trial, having a 16-day PHI.

Samples were analyzed for clethodim residues as DME and DME-OH using USDA’s Yakima Agriculture Research Working Method, version #4, derived from “Valent U.S.A. Corporation procedure RM-26B-3 Determination of Clethodium Residues in Crops, Chicken and Beef Tissues, Milk, and Eggs, 1994,” with minor modifications.  This analytical method is acceptable as a data-gathering method.  The LLMVs in this study were estimated to be 0.10 ppm for both DME and DME-OH.  The LOQs for the method were estimated to be 0.041 ppm for DME and 0.12 ppm for DME-OH.  The LODs were estimated to be 0.01 ppm for DME and 0.04 ppm for DME-OH.  The maximum storage interval for field treated samples in this study was 456-459 days.  Freezer storage stability data show that clethodim and its metabolites were stable for the duration sample storage.  Clethodim residues were 1.24-2.55 ppm in treated succulent shelled pea samples and 0.58-1.84 ppm on edible-podded peas.

Using the supplied residue data and the MRL Calculator, a tolerance level of 3.5 ppm is recommended for the commodity succulent pea.  The MRL calculations can be found in the appendix.

Conclusions:  Adequate crop field trials, numbers, crops, and geographic locations, were submitted for this crop group.  Based on the highest calculated individual tolerance of 3.5 ppm for the RAC succulent pea, as recommended by the MRL calculator, ARIA recommends for a tolerance be established at 3.5 ppm for the vegetable, legume crop group 6 (except soybean) (ChemSAC, 08/FEB/2006).   A revised Section F must be submitted by the petitioner changing the requested tolerance from 3.0 ppm to 3.5 ppm as recommended by ARIA and MRL spreadsheet calculations.

860.1520 Processed Food and Feed

45858501-02.der, L.Kutney, 09/NOV/2006

46434605-02.der, L. Kutney, 07/NOV/2006

  SEQ CHAPTER \h \r 1 IR-4 has submitted field trial residue data for clethodim on flax and sesame.  Six field trials were conducted for flax in the 2000 growing season in North Dakota (3 trials, EPA Regions 5 and 7) and South Dakota (3 trialsEPA Region 5) and four field trials were conducted for sesame in Texas (EPA Region 6) during the 2000 growing season.  All field trial sites consisted of one untreated control plot and one treated plot.

Two broadcast spray applications of clethodim (Prism® 0.94 EC) were applied at ~ 0.25 lb ai/A (~0.50 lb ai/A per season), a 1X rate, with 13-15 days between applications, and then harvested with a pre-harvest interval of 12-18 days.  Field treated samples were stored up to 91 days for flax meal, 181 days for flax oil, 50 days for sesame meal and 58 days for sesame oil.

Two untreated (control) and two treated samples were taken from each field trial, to ensure a representative sample.  An additional two samples were collected from the ND13 trial (one treated and one untreated) for processing into flax seed oil and meal and samples collected from the 00-TX48 trial were processed into sesame meal and oil.

The residues of clethodim in flax seeds and sesame seeds were analyzed via GC/FPD-S, as DME and DME-OH, reported as clethodim equivalents.  The analytical method was validated at three fortification levels of CSO and 5-OH CSO2: 0.10, 1.0 and 5.0 ppm, corresponding to 0.078/0.076, 0.78/0.76 ppm and 3.9/3.8 ppm of DME/DME-OH, respectively.  Concurrent recoveries were generally acceptable.  Recoveries for flax meal were 77-96% for DME and 74-108% for DME-OH.  Recoveries for flax oil were 75-104% for DME and 80-112% for DME-OH.  Recoveries for sesame meal were 90% for DME and 109% for DME-OH.  Recoveries for sesame oil were 81-88% for DME and 93% for DME-OH.

Total clethodim residues ranged from an average of 0.18-0.41 ppm on treated flax seeds.  Total clethodim residues on flax meal and flax oil averaged <0.18 ppm; therefore, the processing factor for flax meal and oil are <0.8.  Total clethodim residues ranged from an average of 0.24-0.28 ppm on treated sesame seeds.  Total clethodim residues on sesame meal and oil averaged 0.31 ppm and 0.37, repectively; therefore, the processing factor for sesame meal and oil are 1.2 and 1.4, respectively.

Processed flax meal and oil samples from flax seed containing clethodim residues of 0.22 ppm were stored for up to 132 and 223 days, respectively.  The maximum storage interval for field treated samples was 50 days for sesame meal and 58 days for sesame oil.  Freezer storage stability data were adequate.  Concurrent DME recoveries were 52-75% in flax meal, 55-75% flax oil, respectively.  Concurrent DME-OH recoveries were 73% in meal and in 67-80% flax oil. Concurrent recoveries were 90-109% in sesame oil, and 84-93% in sesame oil.  Residues of clethodim were determined to be adequately stable.

TABLE 10  Residue Data From Flax and Sesame Seed, Meal and Oil Crop Field Trials with Clethodim.

Trial ID

City, State

Year	Commodity	Region	Total Rate

(lbs ai/A)	PHI (days)	Clethodim

from

DME

(ppm)	Clethodim

from

DME-OH (ppm)	Total Clethodim (ppm)	Average

Clethodim (ppm)

Processing

Factor

Flax

ND13

Fargo, ND

 2000	Flax, seed

	5	0.516	14	<0.095, 0.15	<0.088, <0.088	<0.19, <0.24	<0.22	-

ND13

Fargo, ND

 2000	Flax, meal

	5	0.516	14	<0.095	<0.088	<0.183	<0.18	<0.8

ND13

Fargo, ND

 2000	Flax, oil

	5	0.516	14	<0.095	<0.088	<0.183	<0.18	<0.8

Sesame

00-TX48

(Mercedes, TX

2000)	Sesame, seed	6	0.50	15	0.15, 0.18	<0.088, 0.095	0.24, 0.28	0.26	1

00-TX48

(Mercedes, TX

2000)	Sesame, meal	6	0.50	15	0.22	0.088	0.31	0.31	1.2

00-TX48

(Mercedes, TX

2000)	Sesame, oil	6	0.50	15	0.20	0.17	0.37	0.37	1.4

Conclusions:  All the processing factors, except for sesame, oil, are less than or equal to 1.2X which is the level at which residues in processed commodities may be of concern.  If HAFT X Processing Factor > tolerance on sesame, seed, then a tolerance is required, otherwise the RAC tolerance is sufficient.  The processing factors determined by these studies will not raise the residues above the tolerances recommended by ARIA for these RACs.  Therefore, a separate tolerance is not needed for sesame, oil.  The previously established tolerance based on the translation of data from a canola processing study (PP# 0E006202, DP Num: 271248, M. Xue, 14/JUN/2001) for flax, meal at 1.0 ppm must be removed.

860.1650 Submittal of Analytical Reference Standards

The analytical reference standards for both DME and DME-OH (June 1993) have been previously submitted to the EPA National Pesticide Standards Repository.  However, the petitioner must resubmit reference standards to update expired samples.

860.1850/860.1900 Confined and Field Accumulation in Rotational Crops

A confined rotational crop study of [ring-4,6-14C]-clethodim with carrots, lettuce, and wheat (MRID 41030211) was conducted.  The study was reviewed by E. B. Conerly (EFGWB Science Chapter for Clethodim, 26/JUN/1990).  Results indicated that there is no need for field rotational crop trials.  A 1- month plantback interval for crops rotated with alfalfa was specified (DP Num: 236382, M. Collantes, et. al, 10/FEB/1998).  The use directions submitted with the current petitions do not specifically address rotational crops.  The directions for use on fallow or nonproducing agricultural land state do not plant any crop for 30 days after application unless clethodim is registered for use on that crop.

860.1550 Proposed Tolerances

The tolerance expression for clethodim in/on plants (40 CFR 180.458(a) (3) is the combined residues of clethodim and metabolites containing the 5-(2-(ethylthiopropyl)cyclohexene-3-one and 5-(2-(ethylthiopropyl)-5-hydroxycyclohexene -3-one moieties and their sulphoxides and sulphones.

Table 11.  Tolerance Summary for Clethodim

Commodity	Established/Proposed Tolerance (ppm)	Recommended Tolerance (ppm)	Comments (correct commodity definition)

Leafy greens subgroup 4A	2.0	                     2.0

	Flax, seed	0.5	                     0.6

	Hop, dried cones	0.50	                     0.5

	Asparagus	2.0	                     1.7

	Herb subgroup 19A	10	                    12.0

	Sesame, seed	0.40	                     0.35

	Vegetable, legume, group 6, except soybean	3.0	                     3.5 Corrected commodity definition.

Safflower, meal	10.0	                    10.0

	Safflower, seed	5.0	                     5.0

Based on the newly submitted field trial data, harmonization with current Codex Tolerances set on beans (dry), beans, except broad bean and soya bean, field pea is not appropriate (ChemSAC, minutes of 08/FEB/2006).  The Codex Status of these commodities should be increased to accommodate this new data.  Harmonization with Canada on the tolerance for flax seed, beans, chickpeas, lentils, and peas (dry) and Mexico on bean (kidney) is also not possible based on the MRL Calculations of the newly submitted data.

ATTACHMENTS:

Attachment 1:  Feedstuffs with clethodim established or proposed tolerances

Attachment 2:  Worksheet: Reasonably Balanced Diets

Attachment 3:  International Residue Limit Status

Attachment 4:  MRL Calculations and Residue Data

Attachment 1:

Feedstuffs with clethodim established or proposed tolerances

Feedstuff	Classification	Tolerance

alfalfa, forage	Roughage	6.0

alfalfa, hay	R	10.0

clover, forage	R	10.0

clover, hay	R	20.0

beet, sugar, tops	R	1.0

peanut, hay	R	3.0

beet, sugar, molasses	Carbohydrate Concentrate	1.0

beet, sugar, root	CC	0.2

potato, processed waste	CC	0.5 (based on potato)

canola, meal	Protein concentrate	1.0

canola, seed	PC	0.5

cotton, meal	PC	2.0

cotton, undelinted seed	PC	1.0

flax, meal	PC	1.0

flax, seed	PC	0.5  (0.6)

peanut, meal	PC	5.0

safflower, meal	PC	10.0

safflower, seed	PC	5.0

soybean (seed)	PC	10.0

soybean, soapstock	PC	15.0

sunflower, meal	PC	10.0

sunflower, seed	PC	5.0

Comments:

Alfalfa forage and hay are chosen over clover forage and hay mainly because of the US total acreage and the more common usage of alfalfa over clover all across the US.  Alfalfa is replacing clover in many livestock productions.  Most of alfalfa is grown for hay production.  Clover, because of tendency to develop high fungus levels quickly, is usually grow as mixed stands with cool season grasses (e.g., timothy, blue, fescue).  Both alfalfa and clover are better pastured with mixed stands of grasses.  Clover can also cause bloating if overfed or grazed in pure stands, and can sometimes affect livestock reproduction.

Sugarbeet tops are not considered a significant feedstuff.

Peanut hay can be fed, but production volumes limit extended use vs. alfalfa hay use.

Sugarbeet molasses is added to beef and dairy rations for palatability.

Sugarbeet root is not likely to added to ration if sugarbeet molasses is already an ingredient in feed.

Potato processed waste can be fed to both beef and dairy.  The tolerance for potato (0.5 ppm) is used for the waste product.

Undelinted cottonseed is commonly used in dairy productions as the protein concentrate.

Soybean meal is commonly used as the protein concentrate for livestock ration.  Soybean seed can be used for best estimate.  Oilseed meals are generally included in beef rations, most commonly soybean, but safflower and/or sunflower meals give the same estimate. Likewise poultry rations generally contain soybean meal, but the aforementioned meals will provide similar estimate. The other meals and seeds with established tolerances can also be fed, but in limited quantities, and feeding would give lower burdens since tolerances are less (i.e., 1.0 to 5.0 ppm).

Soybean soapstock is not considered a significant feedstuff.

Attachment 2:

				WORKSHEET:  Reasonably Balanced Diets

Livestock dietary burdens for (clethodim) a.

	%  Diet b	Residue (ppm)

Feedstuff	Type	Tolerance, ppm	% Dry Matter	Beef	Dairy	Poultry	Swine	Beef 	Diary 	Poultry 	Swine

alfalfa, forage	R	6.0	35

20

3.4

alfalfa,  hay	R	10.0	89	15

1.7

	Grass /nongrass/ cereal grain,  forage/silage/hay	R	0

	25

beet, sugar, molasses	CC	1.0	75	5	5

	0.07	0.07

potato, processed waste	CC	0.5	20	30	10

	0.75	0.25

Corn, field, grain /other grains/grain milled byproducts) 	CC	0

40	30	70	85

cotton, undelinted seed	PC	1.0	88

10

0.11

safflower/sunflower, meal	PC	10.0	88	10

10

1.1

1.0

soybean,  seed	PC	10.0	89

	20	15

	2.0	1.5

Totals

100	100	100	100	3.6	3.8	3.0	1.5

a    All data are based on Table 1 Feedstuffs (October 2006), a revision of feedstuffs data found in Table 1 (180.1000 OPPTS Test Guidelines).  Residue levels for beef and dairy are corrected for moisture content and are determined by formula: tolerance / %DM  x  % in diet.  Residue levels for poultry and swine are considered “as-is” and are determined by formula: tolerance  x   % in diet.  R: roughage; CC: carbohydrate concentrate;  PC:  protein concentrate.

b   Typical compositions of daily rations for the animals of choice for Table 1 data  follow:

Feedlot beef  have a daily ration of 15-40 %  R, 45-80 %  CC, and 10-15 %  PC.  As the slaughter time (last 3 months) gets closer, then the beef cattle are fed higher amounts of CC (up to 80 %), and lower amounts of  R (15-20 %) and PC (5-10 %).  The average life span for feedlot beef is 16-18 months   Most of feedlot beef are slaughtered in 4 major centers located in the Midwest and the processed meat is “boxed” and shipped to distributors for sale to local grocers.  Commercial ground beef (75-93 % lean) is produced from the combination of feedlot beef (60-70 % lean) and other lean meat sources, i.e., beef cows and bulls from cow-calf operations, imported lean meat trimmings, and replacement non-lactating dairy cows.

High volume milk-producing lactating dairy cows have a daily ration of 45 % R, 40-45 % CC, and 10-15 % PC.  Dairy cows usually produce 2-3 calves before slaughter. The average life span of the lactating dairy cow is 3-4 years.  Upon slaughter, much of the meat is used in ground beef and processed foods e.g., deli meats, soups, frozen dinners/entrees.

A laying hen that will give a steady egg production is fed 75-80 % CC and 20-25 % PC.   The life span can be up to 18 months.  In general, laying hens are not processed and marketed as whole or cut-up chickens. Much of the layer meat is used in processed food products, e.g., deli meats, soups, canned chicken, etc.  (Note:  The laying hen is the animal of choice.  Frying and rotisserie chickens come from the broiler, a fast food chicken, weighing 3.5-4.0 lb.), and an animal that is raised in a very short time.  The average life span is 38-42 days.  The broiler diet contains 85-90 % CC and 10-15 % PC.

A marketable hog diet that will give steady growth would have 80-85 % CC and 15-20 % PC.  Most of the US hog production is confined to “mega” operations.  Animals are born in in-house nurseries, and simply moved to connecting buildings as the animal grows until slaughter (250 lb finished animal in 6 months). These animals provide meat for the “fresh pork” market.

Note:  These guidelines are not to be used for pesticide residues that bioaccumulate.  Contact Health Effects Division, OPP, EPA for these types of pesticides.

Attachment 3:

INTERNATIONAL RESIDUE LIMIT STATUS

Chemical Name:

((E)-(()-2-[1-[[(3-chloro-2-propenyl)oxy]imino]propyl]-5-[2-(ethylthio)p ropyl]-3-hydroxy-2-cyclohexen-1-one

Common Name: Clethodim

X Proposed tolerance

( Reevaluated tolerance

( Other

Date: 01/03/2007

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: 4E6836

DP Num: 334913

Other Identifier:

Residue definition (step 8/CXL): Sum of clethodim and its metabolites containing 5-(2-ethylthiopropyl) cyclohexene-3-one and 5-(2-ethylthiopropyl)- 5-hydroxycyclohexene- 3-one moieties and their sulphoxides and sulphones, expressed as clethodim

Reviewer/Branch: Debra Rate/RIMUERB

Residue definition: combined residues of ((E)-(()-2-[1-[[(3-chloro-2-propenyl)oxy]imino]propyl]-5-[2-(ethylthio)p ropyl]-3-hydroxy-2-cyclohexen-1-one and its metabolites containing the 5-(2-ethylthiopropyl)cyclohexene-3-one and 5-(2-(ethylthiopropyl)-5-hydroxycyclohexene-3-one moieties and their sulphones and sulphoxides

Crop (s)

MRL (mg/kg)

Crop(s)

Tolerance (ppm)

Beans (dry)

2

Herb Subgroup 19A

8.0

Beans, except broad bean and soya bean

0.5 (*)

Hop, dried cones

0.50

Field peas (dry)

2

Aparagus

1.5

Soya bean (dry)

10

Sesame, seed

0.40

Vegetable, legume, group (Crop Group 6)

3.5

Safflower, meal

10

Safflower, seed

5.0

Leafy Greens, Subgroup 4A	3.0

Flax, seed	0.60

Limits for Canada

Limits for Mexico

(  No Limits

(No Limits for the crops requested

(No Limits

( No Limits for the crops requested

Residue definition:  (E,E)-(±)-2-[1-[[-3-chloro-

2-propenyl)oxy]imino]propyl]-5-[2-(ethylthio)

propyl]-3-hydroxy-2-cyclohexen-1-one,

including metabolites containing the 2-

cyclohex-1-enone moiety

Residue definition:  clethodim

Crop(s)

MRL (ppm)

Crop(s)

MRL (ppm)

Soybeans	10	Bean (kidney bean)	2

Beans	0.5	Soya bean	10

Chickpeas	0.5

Lentils	0.5

Peas (dry)	0.5

Flaxseed	0.3

S. Funk, 01/03/07

Attachment 4:

Regulator:	EPA

Chemical:	Clethodim

Crop:	Basil Fresh

PHI:	20-21

App. Rate:

	Submitter:

Residues	LN(Residues)	Z-scores

	0.920	-0.08	-1.28

	0.980	-0.02	-0.64

	1.120	0.11	-0.20

	1.120	0.11	0.20

	1.220	0.20	0.64

	1.320	0.28	1.28

Regulator:	EPA

Chemical:	Clethodim

Crop:	Chives

PHI:	20-22

App. Rate:

	Submitter:

Residues	LN(Residues)	Z-scores

	0.340	-1.08	0.00

	0.320	-1.14	-0.27

	0.240	-1.43	-1.49

	0.240	-1.43	-0.93

	0.780	-0.25	0.27

	0.780	-0.25	0.57

	2.160	0.77	1.49

	1.640	0.49	0.93

	0.240	-1.43	-0.57

Regulator:	EPA

Chemical:	Clethodim

Crop:	Sesame

PHI:

	App. Rate:

	Submitter:

Residues	LN(Residues)	Z-scores

	0.240	-1.43	0.15

	0.280	-1.27	1.43

	0.260	-1.35	0.47

	0.270	-1.31	0.85

	0.190	-1.66	-1.43

	0.210	-1.56	-0.47

	0.200	-1.61	-0.85

	0.210	-1.56	-0.15

Regulator:

	Chemical:	Clethodim

Crop:	Lima Beans

PHI:

	App. Rate:

	Submitter:

Residues	LN(Residues)	Z-scores

	0.600	-0.51	1.28

	0.650	-0.43	1.77

	0.410	-0.89	0.08

	0.590	-0.53	0.99

	0.480	-0.73	0.23

	0.550	-0.60	0.40

	0.260	-1.35	-0.99

	0.280	-1.27	-0.57

	0.180	-1.71	-1.77

	0.180	-1.71	-1.28

	0.560	-0.58	0.57

	0.570	-0.56	0.76

	0.310	-1.17	-0.40

	0.330	-1.11	-0.08

	0.270	-1.31	-0.76

	0.310	-1.17	-0.23

Regulator:	EPA

Chemical:	Clethodim

Crop:	Succulent Pea

PHI:

	App. Rate:

	Submitter:

Residues	LN(Residues)	Z-scores

	2.090	0.74	1.28

	2.550	0.94	1.77

	1.390	0.33	-0.40

	1.560	0.44	0.08

	1.240	0.22	-0.99

	1.460	0.38	-0.23

	1.830	0.60	0.57

	1.970	0.68	0.99

	1.340	0.29	-0.57

	1.470	0.39	-0.08

	1.630	0.49	0.40

	1.840	0.61	0.76

	1.330	0.29	-0.76

	1.620	0.48	0.23

	0.580	-0.54	-1.77

	0.620	-0.48	-1.28

Regulator:	EPA

Chemical:	Clethodim

Crop:	Dry Pea

PHI:

	App. Rate:

	Submitter:

Residues	LN(Residues)	Z-scores

	0.180	-1.71	-1.64

	0.200	-1.61	-1.11

	0.260	-1.35	-0.79

	0.260	-1.35	-0.54

	1.070	0.07	1.11

	1.240	0.22	1.64

	0.640	-0.45	0.10

	0.770	-0.26	0.31

	0.780	-0.25	0.54

	0.950	-0.05	0.79

	0.400	-0.92	-0.31

	0.420	-0.87	-0.10

Regulator:	EPA

Chemical:	Clethodim

Crop:	Lettuce Head

PHI:

	App. Rate:

	Submitter:

Residues	LN(Residues)	Z-scores

	0.470	-0.76	0.79

	0.490	-0.71	1.11

	0.270	-1.31	-0.79

	0.300	-1.20	-0.10

	0.250	-1.39	-1.11

	0.560	-0.58	1.64

	0.280	-1.27	-0.54

	0.390	-0.94	0.31

	0.280	-1.27	-0.31

	0.300	-1.20	0.10

	0.390	-0.94	0.54

	0.170	-1.77	-1.64

Clethodim	Summary of Analytical Chemistry and Residue Data		Barcode: D334913

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