clethodim (Prism, Select) Pesticide Petition Filing 3/02
ENVIRONMENTAL PROTECTION AGENCY
Notice of Filing Pesticide Petitions to Establish a Tolerance for
Certain Pesticide Chemicals in or on Food
AGENCY: Environmental Protection Agency (EPA).
SUMMARY: This notice announces the initial filing of pesticide
petitions proposing the establishment of regulations for residues of
certain pesticide chemicals in or on various food commodities.
DATES: Comments, identified by docket control number PF-1080, must be
received on or before May 17, 2002.
ADDRESSES: Comments may be submitted by mail, electronically, or in
person. Please follow the detailed instructions for each method as
provided in Unit I.C. of the SUPPLEMENTARY INFORMATION. To ensure
proper receipt by EPA, it is imperative that you identify docket
control number PF-1080 in the subject line on the first page of your
FOR FURTHER INFORMATION CONTACT: Shaja R. Brothers, Registration
Division (7505C), Office of Pesticide Programs, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460;
telephone number: (703) 308-3194; e-mail address:
I. General Information
A. Does this Action Apply to Me?
You may be affected by this action if you are an agricultural
producer, food manufacturer or pesticide manufacturer. Potentially
affected categories and entities may include, but are not limited to:
Categories NAICS codes potentially
Industry 111 Crop production
112 Animal production
311 Food manufacturing
This listing is not intended to be exhaustive, but rather provides
a guide for readers regarding entities likely to be affected by this
action. Other types of entities not listed in the table could also be
affected. The North American Industrial Classification System (NAICS)
codes have been provided to
assist you and others in determining whether or not this action might
apply to certain entities. If you have questions regarding the
applicability of this action to a particular entity, consult the person
listed under FOR FURTHER INFORMATION CONTACT.
B. How Can I Get Additional Information, Including Copies of this
Document and Other Related Documents?
1. Electronically. You may obtain electronic copies of this
document, and certain other related documents that might be available
electronically, from the EPA Internet Home Page at http://www.epa.gov/.
To access this document, on the Home Page select ``Laws and
Regulations'' and then look up the entry for this document under the
``Federal Register--Environmental Documents.'' You can also go directly
to the Federal Register listings at http://www.epa.gov/fedrgstr/.
2. In person. The Agency has established an official record for
this action under docket control number PF-1080. The official record
consists of the documents specifically referenced in this action, any
public comments received during an applicable comment period, and other
information related to this action, including any information claimed
as confidential business information (CBI). This official record
includes the documents that are physically located in the docket, as
well as the documents that are referenced in those documents. The
public version of the official record does not include any information
claimed as CBI. The public version of the official record, which
includes printed, paper versions of any electronic comments submitted
during an applicable comment period, is available for inspection in the
Public Information and Records Integrity Branch (PIRIB), Rm. 119,
Crystal Mall #2, 1921 Jefferson Davis Highway, Arlington, VA, from 8:30
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The
PIRIB telephone number is (703) 305-5805.
C. How and to Whom Do I Submit Comments?
You may submit comments through the mail, in person, or
electronically. To ensure proper receipt by EPA, it is imperative that
you identify docket control number PF-1080 in the subject line on the
first page of your response.
1. By mail. Submit your comments to: Public Information and Records
Integrity Branch (PIRIB), Information Resources and Services Division
(7502C), Office of Pesticide Programs (OPP), Environmental Protection
Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460.
2. In person or by courier. Deliver your comments to: Public
Information and Records Integrity Branch (PIRIB), Information Resources
and Services Division (7502C), Office of Pesticide Programs (OPP),
Environmental Protection Agency, Rm. 119, Crystal Mall #2, 1921
Jefferson Davis Highway, Arlington, VA. The PIRIB is open from 8:30
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The
PIRIB telephone number is (703) 305-5805.
3. Electronically. You may submit your comments electronically by
e-mail to: firstname.lastname@example.org, or you can submit a computer disk as
described above. Do not submit any information electronically that you
consider to be CBI. Avoid the use of special characters and any form of
encryption. Electronic submissions will be accepted in Wordperfect 6.1/
8.0 or ASCII file format. All comments in electronic form must be
identified by docket control number PF-1080. Electronic comments may
also be filed online at many Federal Depository Libraries.
D. How Should I Handle CBI That I Want to Submit to the Agency?
Do not submit any information electronically that you consider to
be CBI. You may claim information that you submit to EPA in response to
this document as CBI by marking any part or all of that information as
CBI. Information so marked will not be disclosed except in accordance
with procedures set forth in 40 CFR part 2. In addition to one complete
version of the comment that includes any information claimed as CBI, a
copy of the comment that does not contain the information claimed as
CBI must be submitted for inclusion in the public version of the
official record. Information not marked confidential will be included
in the public version of the official record without prior notice. If
you have any questions about CBI or the procedures for claiming CBI,
please consult the person listed under FOR FURTHER INFORMATION CONTACT.
E. What Should I Consider as I Prepare My Comments for EPA?
You may find the following suggestions helpful for preparing your
1. Explain your views as clearly as possible.
2. Describe any assumptions that you used.
3. Provide copies of any technical information and/or data you used
that support your views.
4. If you estimate potential burden or costs, explain how you
arrived at the estimate that you provide.
5. Provide specific examples to illustrate your concerns.
6. Make sure to submit your comments by the deadline in this
7. To ensure proper receipt by EPA, be sure to identify the docket
control number assigned to this action in the subject line on the first
page of your response. You may also provide the name, date, and Federal
II. What Action is the Agency Taking?
EPA has received pesticide petitions as follows proposing the
establishment and/or amendment of regulations for residues of certain
pesticide chemicals in or on various food commodities under section 408
of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a.
EPA has determined that these petitions contain data or information
regarding the elements set forth in section 408(d)(2); however, EPA has
not fully evaluated the sufficiency of the submitted data at this time
or whether the data support granting of the petition. Additional data
may be needed before EPA rules on the petition.
List of Subjects
Environmental protection, Agricultural commodities, Feed additives,
Food additives, Pesticides and pests, Reporting and recordkeeping
Dated: March 29, 2002.
Robert A. Forrest,
Acting Director, Registration Division, Office of Pesticide Programs.
Summaries of Petitions
Petitioner summaries of the pesticide petitions are printed below
as required by section 408(d)(3) of the FFDCA. The summaries of the
petitions were prepared by the petitioners and represent the views of
the petitioners. EPA is publishing the petition summaries verbatim
without editing them in any way. The petition summary announces the
availability of a description of the analytical methods available to
EPA for the detection and measurement of the pesticide chemical
residues or an explanation of why no such method is needed.
Pesticide Petitions 1E6351, 2E6394, 2E6396, 5F4440, and 5F4572
EPA has received pesticide petitions (1E6351, 2E6394, and 2E6396)
from the Interregional Research Project Number 4 (IR #4), 681 U.S.
Highway #1 South,
North Brunswick, NJ 08902-3390 proposing, pursuant to section 408(d) of
the FFDCA, 21 U.S.C. 346a(d), to amend 40 CFR part 180.458 by
establishing tolerances for residues of clethodim in or on the
following raw agricultural commodities (RACs): Leafy brassica greens
subgroup and turnip tops at 3.0 parts per million (ppm), spinach at 2.0
ppm, peppermint at 5.0 ppm, and spearmint at 5.0 ppm. This notice
includes a summary of the petitions prepared by Valent U.S.A.
Corporation, the registrant.
EPA has also received pesticide petitions (5F4440 and 5F4572) from
the Valent U.S.A. Corporation, 1333 North California Boulevard, Suite
600, Walnut Creek, CA 94596-8025 proposing, pursuant to section 408(d)
of the FFDCA, 21 U.S.C. 346a(d), to amend 40 CFR 180.458 by replacing
existing time-limited tolerances, for residues of clethodim in or on
the following RACs with permanent tolerances: Alfalfa forage at 6.0
ppm, alfalfa hay at 10.0 ppm, dry bean at 2.0 ppm, peanut hay at 3.0
ppm, peanut meal at 5.0 ppm, peanut at 3.0 ppm, tomato paste at 3.0
ppm, and tomato puree at 2.0 ppm.
EPA has determined that the petitions contain data or information
regarding the elements set forth in section 408(d)(2) of the FFDCA;
however, EPA has not fully evaluated the sufficiency of the submitted
data at this time or whether the data support granting of the
petitions. Additional data may be needed before EPA rules on the
A. Residue Chemistry
1. Plant metabolism. The metabolism of 14C-clethodim
labeled in the ring structure and in the side chain has been studied in
carrots, soybeans, and cotton as well as in lactating goats and laying
hens. The major metabolic pathway in plants is initial sulfoxidation,
forming clethodim sulfoxide, followed by further oxidation to form
clethodim sulfone. These reactions are apparently followed by
elimination of the chloroallyloxy side chain to give the imine
sulfoxide and sulfone, with further hydroxylation to form the 5-OH
sulfoxide and 5-OH sulfone. Clethodim sulfoxide and clethodim sulfone
conjugates were also detected as major or minor metabolites, depending
on plant species and subfractions. Once the side chain is cleaved from
clethodim, the chloroallyloxy moiety undergoes extensive metabolism to
eliminate chlorine and incorporate 3-carbon moieties into natural plant
2. Analytical method. Practical analytical methods for detecting
and measuring levels of clethodim and its metabolites have been
developed and validated in/on all appropriate agricultural commodities,
respective processing fractions, milk, animal tissues, and
environmental samples. The methods have been validated at independent
laboratories, and EPA has successfully performed an analytical method
trial. For most commodities, the primary enforcement method is EPA-RM-
26D-3, a high performance liquid chromatography (HPLC) method capable
of distinguishing clethodim from the structurally related herbicide
3. Magnitude of residues. The magnitude of residues is adequately
understood for the proposed commodities.
B. Toxicological Profile
1. Acute toxicity. Clethodim technical is slightly toxic to animals
following acute oral (toxicity category III), dermal (toxicity category
IV), or inhalation exposure (toxicity category IV). Clethodim is a
moderate eye irritant (category III), a skin irritant (category II),
and does not cause skin sensitization in the modified Buehler test in
guinea pigs. In addition, an acute oral no observed adverse effect
level (NOAEL) has been determined in rats to be 300 milligrams/
2. Genotoxicity. Clethodim does not present a genetic hazard.
Clethodim technical did not induce gene mutation in microbial in vitro
assays. A weak response in an in vitro assay for chromosome aberrations
was not confirmed when clethodim was tested in an in vivo cytogenetics
assay up to the maximally tolerated dose level, nor was the response
observed in vitro using technical material of a higher purity. No
evidence of unscheduled DNA synthesis (UDS) was seen following in vivo
exposure up to a dose level near the lethal dose LD50 (1.5
g/kg). This evidence indicates that clethodim does not present a
genetic hazard to intact animal systems.
3. Reproductive and developmental toxicity. No reproductive
toxicity was observed with clethodim technical at feeding levels up to
2,500 ppm. Developmental toxicity was observed in two rodent species,
but only at maternally toxic dose levels. Clethodim is therefore not
considered a reproductive or developmental hazard. These studies
indicate no unique toxicity to the developing fetus or young, growing
The developmental toxicity study conducted with clethodim technical
in the rat resulted in a developmental and maternal NOAEL and lowest
observed adverse effect level (LOAEL) of 100 and 350 (mg/kg/day),
respectively. The NOAEL and LOAEL for developmental toxicity were based
on reductions in fetal body weight and increases in skeletal anomalies.
The developmental toxicity study conducted with clethodim technical
in the rabbit resulted in a maternal toxicity NOAEL and LOAEL of 25 and
100 mg/kg/day, respectively. Maternal toxicity was manifested as
clinical signs of toxicity and reduced weight gain and food consumption
during treatment. Developmental toxicity was not observed, and
therefore the developmental toxicity NOAEL was 300 mg/kg/day, highest
dose tested (HDT). The 2-generation reproduction study conducted with
clethodim technical in the rat resulted in parental toxicity NOAEL and
LOAEL of 500 ppm and 2,500 ppm, respectively, based on reductions in
body weight in males, and decreased food consumption in both
generations. The NOAEL for reproductive toxicity was 2,500 ppm, the
4. Subchronic toxicity. Subchronic oral toxicity studies conducted
with clethodim technical in the rat and dog indicate a low level of
toxicity. Effects observed at high dose levels consisted primarily of
decreased body weights, increased liver size (increased weight and cell
hypertrophy), and anemia (decreased erythrocyte counts, hemoglobin, or
hematocrit) in rats and dogs. The NOAELs from these studies were 500
ppm (ca. 25 mg/kg bwt/day) in rats and 25 mg/kg bwt/day in dogs. A 21-
day dermal toxicity study in rats with clethodim technical showed a
LOAEL at 100 mg/kg bwt/day and a NOAEL at 1,000 mg/kg bwt/day, the HDT.
5. Chronic toxicity. Clethodim technical has been tested in chronic
studies with dogs, rats, and mice. In chronic studies, compound-related
effects noted at high doses included decreased body weight, increased
liver size (liver weight and hypertrophy), and anemia (decreased
hemoglobin, hematocrit, and erythrocyte count). Bone marrow hyperplasia
was observed in dogs at the HDT. No treatment-related increases in
incidence of neoplasms were observed in any study.
Chronic NOAELs were 200 ppm for an 18-month feeding study in mice
and 500 ppm for a 24-month study in rats. EPA has established a chronic
population adjusted dose (cPAD) for clethodim of 0.01 mg/kg bwt/day,
based on the NOAEL in the 1-year oral dog study and an uncertainty
factor (UF) of 100. Effects observed at the LOAEL include alterations
in hematology and
increased absolute and relative liver weights at 75 mg/kg/day.
6. Animal metabolism. Ruminant and poultry metabolism studies
demonstrated that transfer of administered 14C-clethodim
residues to tissues was low. Total 14C-residues in goat
milk, muscle, and tissues accounted for less than 0.5% of the
administered dose (24 ppm in diet for 3 days), and were less than 0.4
ppm in all cases. In poultry treated at 2.2 mg/kg/day for 5 days, total
14C-residues in eggs, muscle, and most tissues were less
than 0.3 ppm, although higher in liver, kidney, and the
gastrointestinal tract. Residues in eggs were less than 0.2 ppm.
7. Metabolite toxicology. Metabolism studies of clethodim in rats,
crop plants, goats, and hens demonstrate that the parent is very
rapidly metabolized, and in animals, eliminated. Because parent and
metabolites are not retained in the body, the potential for acute
toxicity from in situ formed metabolites is low. The potential for
chronic toxicity is adequately tested by chronic exposure to the parent
at the maximum tolerance dose and consequent chronic exposure to the
internally formed metabolites. Two metabolites of clethodim, clethodim
imine sulfone and clethodim 5-hydroxy sulfone, have been tested in
toxicity screening studies to evaluate the potential impact of these
metabolites on the toxicity of clethodim. In general, these metabolites
were found to be less toxic than clethodim technical for acute and oral
toxicity studies; reproduction and teratology screening studies; and
several mutagenicity studies.
8. Endocrine disruption. No special studies to investigate the
potential for estrogenic or other endocrine effects of clethodim have
been performed. However, a large and detailed toxicology data base
exists for the compound including studies in all required categories.
These studies include acute, sub-chronic, chronic, developmental, and
reproductive toxicology studies including detailed histology and
histopathology of numerous tissues, including endocrine organs,
following repeated or long-term exposure. These studies show no
evidence of any endocrine-mediated effects and no pathology of the
endocrine organs. Consequently, Valent USA Corporation concludes that
clethodim does not possess estrogenic or endocrine disrupting
C. Aggregate Exposure
1. Dietary exposure. The Lifeline exposure model (Version 1.0) was
used to calculate chronic dietary exposure to clethodim residues for
the U.S. population using anticipated residues (average residues from
field residue studies) and accounting for the percent of the crop
treated. In addition to existing tolerances and those tolerances
proposed in this notice, potential chronic dietary exposure to the
following treated crops are also included in this analysis: Head
lettuce, asparagus, basil, and chives.
i. Food. The highest average estimated dose from food containing
clethodim residues was 0.002273 mg/kg/day for 2-year old children,
which represents 23% of the chronic population adjusted dose (cPAD) of
0.01 mg/kg/day. The average dose gradually became lower, and after the
age of 16 years, the dose stayed below 0.0008 mg/kg/day (8% of the
cPAD). Generally speaking, the Agency has no cause for concern if total
residue contribution for published and proposed tolerances is less than
100% of the cPAD.
ii. Drinking water. Based on the GENEEC and SCI-GROW models, the
estimated environmental concentrations (EECs) of clethodim for chronic
exposures are estimated to be 24.2 parts per billion (ppb) for surface
water and 0.49 ppb for ground water (June 6, 2001, 66 FR 30325) (FRL-
6785-5). Using standard assumptions about body weight and water
consumption, the worse case chronic exposure from drinking water would,
therefore, be 0.0007 and 0.0024 mg/kg bwt/day for adults and children,
respectively; 24% of the cPAD for children. Based on this worse case
analysis, the contribution of water to the chronic dietary risk exceeds
food, but is still acceptable.
2. Non-dietary exposure. Clethodim is currently registered for use
on the following residential non-food sites: Ornamental plants, wooden
containers for growing plants, golf course turf, walkways, trails, and
paths. There are no indoor uses registered for clethodim. Clethodim
kills grassy weeds and does not control broadleaf weeds. Therefore,
clethodim is not used on broadcast turf, but only on edges and
walkways, thus greatly reducing the risk of residential exposure.
D. Cumulative Effects
In consideration of potential cumulative effects of clethodim and
other substances that may have a common mechanism of toxicity, there
are currently no available data or other reliable information
indicating that any toxic effects produced by clethodim would be
cumulative with those of other chemical compounds. Thus, only the
potential risks of clethodim have been considered in this assessment of
aggregate exposure and effects. Valent USA Corporation will submit
information for EPA to consider concerning potential cumulative effects
of clethodim consistent with the schedule established by EPA on August
4, 1997 (62 FR 42020) (FRL-5734-6), and other subsequent EPA
publications pursuant to the Food Quality Protection Act (FQPA).
E. Safety Determination
1. U.S. population. Using the dietary exposure assessment
procedures described above for clethodim, calculated chronic dietary
exposure -- taking into account percent of crop treated and using
anticipated residues -- from existing and proposed uses of clethodim is
minimal. The estimated chronic dietary exposure from food for the U.S.
population over the age of 16 years was 0.0008 mg/kg bwt/day, 8% of the
cPAD. Addition of the small but worse case potential chronic exposure
from drinking water (calculated above) increases exposure by 0.0007 mg/
kg bwt/day and the maximum occupancy of the cPAD from 8% to 15%.
Generally, the Agency has no cause for concern if total residue
contribution is less than 100% of the cPAD. It can be concluded that
there is a reasonable certainty that no harm will result to the U.S.
population over the age of 16 years from aggregate, chronic exposure to
2. Infants and children. In assessing the potential for additional
sensitivity of infants and children to residues of clethodim, FFDCA
section 408 provides that EPA shall apply an additional margin of
safety, up to ten-fold, for added protection for infants and children
in the case of threshold effects unless EPA determines that a different
margin of safety will be safe for infants and children. The
toxicological data base for evaluating prenatal and postnatal toxicity
for clethodim is complete with respect to current data requirements.
There are no special prenatal or postnatal toxicity concerns for
infants and children, based on the results of the rat and rabbit
developmental toxicity studies or the 3-generation reproductive
toxicity study in rats. Valent USA Corporation concludes that reliable
data support use of the standard 100-fold UF and that an additional UF
is not needed for clethodim to be further protective of infants and
Using the conservative exposure assumptions described above
(anticipated residues and percent of crop treated), the percentage of
the cPAD that will be utilized by dietary (food only) exposure to
residues of clethodim was 22.7% for 2-year old
children (the age at which exposure to clethodim reached a maximum).
Adding the worse case potential incremental exposure to infants and
children from clethodim in drinking water (0.0024 mg/kg bwt/day)
greatly increases the aggregate, chronic dietary exposure and the
occupancy of the cPAD by 24% to 46.7% for children (2 years old). EPA
generally has no concern for exposures below 100% of the cPAD because
the cPAD represents the level at or below which daily aggregate dietary
exposure over a lifetime will not pose appreciable risks to human
health. It can be concluded that there is a reasonable certainty that
no harm will result to infants and children from aggregate, chronic
exposure to clethodim residues.
F. International Tolerances
Codex, Canadian, or Mexican maximum residue levels (MRLs) have been
established or proposed for residues of clethodim in/on sugar beets
(0.1 ppm), potatoes (0.2 ppm), rape seed (0.5 ppm), rape seed oils (0.5
ppm), sunflower seed (0.5 ppm), and sunflower seed oils (0.05 ppm).
There are no conflicts between this proposed action and existing
international residue limits.
[FR Doc. 02-9323 Filed 4-16-02; 8:45 am]
BILLING CODE 6560-50-S