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

  PAGE  46  of(  NUMPAGES  46 

