[Federal Register Volume 66, Number 60 (Wednesday, March 28, 2001)]
[Notices]
[Pages 16934-16939]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-7640]


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ENVIRONMENTAL PROTECTION AGENCY

[PF-1003; FRL-6773-5]


Notice of Filing Pesticide Petitions to Establish Tolerances for 
a Certain Pesticide Chemical in or on Food

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice.

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SUMMARY: This notice announces the initial filing of pesticide 
petitions proposing the establishment of regulations for residues of a 
certain pesticide chemical in or on various food commodities.

DATES: Comments, identified by docket control number PF-1003, must be 
received on or before April 27, 2001.

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-1003 in the subject line on the first page of your 
response.

FOR FURTHER INFORMATION CONTACT: By mail: Joanne I. Miller, 
Registration Division (7505C), Office of Pesticide Programs, 
Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460; telephone number: (703) 305-6224; e-mail address: 
[email protected].

SUPPLEMENTARY INFORMATION:

[[Page 16935]]

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:

------------------------------------------------------------------------
                                                          Examples of
           Categories                 NAICS codes         potentially
                                                      affected  entities
------------------------------------------------------------------------
Industry                          111                 Crop production
                                  112                 Animal production
                                  311                 Food manufacturing
                                  32532               Pesticide
                                                       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-1003. 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-1003 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: [email protected], 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-1003. 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 identified 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 
comments:
    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 
notice.
    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 
Register citation.

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 a certain 
pesticide chemical 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 contains 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 petitions. Additional data 
may be needed before EPA rules on these petitions.

List of Subjects

    Environmental protection, Agricultural commodities, Feed additives, 
Food additives, Pesticides

[[Page 16936]]

and pests, Reporting and recordkeeping requirements.

    Dated: March 19, 2001.
  James Jones,
Director, Registration Division, Office of Pesticide Programs.

Summaries of Petitions

    The 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 petitioner and represents the view 
of the petitioner. EPA is publishing the petition summaries verbatim 
without editing them in any way. The petitioner's summaries 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.

Valent U.S.A. Corporation

PP 5F4440 and 5F4572

    EPA has received amended pesticide petitions (5F4440 and 5F4572) 
from Valent U.S.A. Corporation, 1333 N. California Blvd., Ste. 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 part 180 by extending 
time-limited tolerances for residues of clethodim in or on the raw 
agricultural commodities (RACs) alfalfa forage at 6 parts per million 
(ppm), alfalfa hay at 10 ppm, dry beans at 2 ppm, peanut hay at 3 ppm, 
peanut meal at 5 ppm, peanuts at 3 ppm, tomato paste at 3 ppm, and 
tomato puree at 2 ppm. Time-limited tolerances on these commodities 
would expire on April 30, 2003, to allow EPA sufficient time to 
evaluate new residue data. Valent USA Corporation is not proposing to 
extend the time-limited tolerance for residues on tomatoes at 1.0 ppm 
because tolerances are to be issued for residues on fruiting vegetables 
(except cucurbits), which includes tomatoes, at 1.5 ppm through a 
separate pesticide petition (0E6097). EPA has determined that the 
petition contains 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 petition. Additional data may be needed before 
EPA rules on the petition. This notice includes a summary of the 
petitions prepared by Valent U.S.A. Corporation, the registrant.

A. Residue Chemistry

    1. Plant metabolism. The metabolism of 14C-clethodim 
labelled 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 three-carbon moieties 
into natural plant components.
    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 
sethoxydim.
    3. Magnitude of residues--i. Fruiting vegetables. There is an 
existing time-limited tolerance for tomatoes of 1.0 ppm and Valent 
U.S.A. Corporation is proposing to replace this tolerance with a 1.5 
ppm tolerance for fruiting vegetables based on residue trials conducted 
on peppers (bell and non-bell) and tomatoes. Six field trials for bell 
peppers were treated with two post-emergent applications of 0.25 lb. 
a.i./acre each. Bell pepper fruit was harvested approximately 21 days 
after the last application. Residues in/on bell pepper fruit samples 
ranged from 0.11 ppm to 0.89 ppm total clethodim. The highest average 
field trial (HAFT) residue was 0.79 ppm. The average residue level was 
0.46 ppm. Five field trials for non-bell peppers were treated with two 
post-emergent applications of 0.25 lb. a.i./acre each. Non-bell pepper 
fruit was harvested approximately 21 days after the last application. 
Residues in/on non-bell pepper fruit samples ranged from 0.12 ppm to 
0.92 ppm total clethodim. The HAFT residue was 0.90 ppm. The average 
residue level was 0.55 ppm.
    Twelve residue trials for tomatoes were treated with two post-
emergent applications of 0.25 lb. a.i./acre each. Tomatoes were 
harvested approximately 20 days after the last application. Clethodim 
residues ranged from <0.1 to 0.79 ppm. The HAFT residue was 0.77 ppm. 
The average residue level was 0.37 ppm. To support permanent tolerances 
on tomatoes, Valent U.S.A. Corporation agreed to conduct four 
additional residue trials in EPA Region X to bring the total number of 
trials up to 16. In these four additional trials, tomatoes were treated 
with two post-emergent applications of 0.25 lb. a.i./acre each. 
Tomatoes were harvested approximately 20 days after the last 
application. Clethodim residues ranged from 0.34 to 1.07 ppm. The 
average residue level for all 16 tomato residue trials was 0.42 ppm. 
The HAFT residue was 1.04 ppm.
    Combining the pepper residue data and the tomato residue data gives 
an overall average residue in fruiting vegetables of 0.45 ppm. These 
data from bell and non-bell peppers and tomatoes support a tolerance 
for fruiting vegetables (except cucurbits, crop group 8) of 1.5 ppm.
    ii. Dry beans. There is an existing time-limited tolerance for dry 
beans of 2.0 ppm. This tolerance was supported by nine field trials in 
which beans were treated with two post-emergent applications of 0.25 
lb. a.i./acre each approximately 14 days apart. Beans were harvested 
approximately 30 days after the last application. Clethodim residues 
ranged from 0.58 ppm to 1.57 ppm. The HAFT residue was 1.57 ppm. The 
average residue level for all trials, excluding samples less than the 
limit of detection, was 0.99 ppm.
    To support permanent tolerances on dry beans, Valent U.S.A. 
Corporation agreed to conduct 3 additional residue trials in EPA Region 
V to bring the total number of trials up to 12. In these 3 additional 
trials, beans were treated with two post-emergent applications of 0.25 
lb. a.i./acre each approximately 14 days apart. Beans were harvested 
approximately 30 days after the last application. Clethodim residues 
ranged from 1.2 ppm to 2.0 ppm. The average residue level for all 12 
residue trials, excluding samples less than the limit of detection, was 
1.15 ppm. The HAFT residue was 2.0 ppm.
    iii. Peanuts. There is an existing time-limited tolerance for 
peanut hay at 3 ppm, peanut meal at 5 ppm, peanuts at 3 ppm. This 
tolerance was supported by eight field trials in which peanuts were

[[Page 16937]]

treated with two post-emergent applications of 0.25 lb. a.i./acre each 
approximately 14 days apart. Peanuts were harvested approximately 40 
days after the last application. Peanuts were dried in the field for 3 
to 11 days after which peanuts and peanut hay were sampled. Clethodim 
residues ranged from <0.05 ppm to 2.7 ppm. The HAFT residue was 1.75 
ppm. The average residue level, excluding samples less than the limit 
of detection, was 0.96 ppm. Residues in peanut hay ranged from 0.22 ppm 
to 2.6 ppm with a HAFT residue of 2.55 ppm. A processing study was also 
performed for peanuts and residues were found to concentrate in meal 
with a concentration factor of 2.78 ppm.
    To support permanent tolerances on peanuts, Valent U.S.A. 
Corporation agreed to conduct 3 additional residue trials in EPA Region 
V to bring the total number of trials up to 12. In these three 
additional trials, peanuts were treated with two post-emergent 
applications of 0.25 lb. a.i./acre each approximately 14 days apart. 
Peanuts were harvested approximately 40 days after the last 
application. Clethodim residues ranged from 0.67 ppm to 1.2 ppm in 
nutmeats and from 0.8 ppm to 2.9 ppm in peanut hay. The average residue 
level for all 12 residue trials, excluding samples less than the limit 
of detection, was 0.94 ppm in nutmeats and 1.39 ppm in peanut hay. The 
HAFT residue was 1.75 ppm and 2.7 ppm in nutmeats and hay, 
respectively.

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/kilogram 
(mg/kg).
    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 LD50 (1.5 gram/kilogram 
(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 
animals. 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 milligrams/
kilograms/day (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, HDT.
    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 body weight/day (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 track (GI) tract. Residues in eggs were less than 0.2 
ppm.
    Comparing metabolites detected and quantified from plant and animal 
metabolism studies shows that there are no significant aglycones in 
plants which are not also present in the excreta or tissues of animals. 
Based on these metabolism studies, the residues of concern in crops and 
animal products are clethodim and its metabolites containing the 
cyclohexene moiety, and their sulfoxides and sulfones.
    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 (MTD) 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

[[Page 16938]]

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 U.S.A. Corporation concludes 
that clethodim does not possess estrogenic or endocrine disrupting 
properties.

C. Aggregate Exposure

    1. Dietary exposure--i. Food. Chronic dietary exposure to clethodim 
residues was calculated for the U.S. population and 26 population 
subgroups using anticipated residues (average residues from field 
residue studies) and accounting for the percent of the crop treated. A 
parallel analysis was performed assuming 100% 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 and crop groups is also included in this analysis: sunflower, 
canola, tuberous and corm vegetables (crop subgroup 1C), root 
vegetables (except sugarbeet, subgroup 1B), leaves of root and tuber 
vegetables (group 2), leaf petioles (subgroup 4B), cucurbits (group 9), 
cranberry, strawberry, and clover.
    Chronic dietary exposure was at or below 4.5% of the reference dose 
(RfD) when accounting for the percent of the crop treated. Calculated 
exposure increased to a maximum of 32.1% non-nursing infants (<1 year 
old) using anticipated residues and assuming 100% of the crop treated. 
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. Since clethodim is applied outdoors 
postemergance to growing agricultural crops, the potential exists for 
clethodim and/or its metabolites to reach ground or surface water that 
may be used for drinking water. To model very conservative estimates of 
the potential concentrations of clethodim and its sulfoxide metabolite 
in drinking water, the Agency used screening concentration in ground 
water (SCI-GROW) for ground water, and generic expected environmental 
concentration (GENEEC) for surface water. The sum of the parent and 
metabolite estimated concentrations in surface water greatly exceeded 
those in ground water. Dividing the GENEEC derived 56-day average 
concentration by three gives 10 micrograms per liter parts per billion 
(ppb) as the Agency's worse case estimate for drinking water 
contamination (63 FR 1701, April 8, 1998), (FRL-5784-9). Using standard 
assumptions about body weight and water consumption, the chronic 
exposure from this drinking water would be 0.00029 and 0.001 mg/kg bwt/
day for adults and children, respectively; 10% 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 grassey weeds, and does not control broadleaf weeds. Therefore, 
clethodim is not used broadcast on turf, but only on edges and 
walkways, thus greatly reducing the risk of residential exposure. There 
is one exception, under several state 24(c) registrations, clethodim 
can be used broadcast on winter dormant perennial turf to control 
annual grasses. It is conceivable that these outdoor uses could result 
in acute or short-term residential exposure. However, under current EPA 
criteria, the registered and proposed uses of clethodim would not 
constitute a chronic residential exposure scenario. The Agency did 
calculate that these potential exposures to homeowner applicators and 
other potential exposed individuals lead to acceptable margins of 
exposure (MOE) (63 FR 1701). However, because the Agency did not 
identify short- or intermediate-term dermal toxic endpoints of concern, 
these risk analyses are no longer necessary.

D. Cumulative Effects

    There are other pesticidal compounds that are structurally related 
to clethodim including sethoxydim, cycloxydim, and tralkoxydim. 
Analytical methods convert some of these herbicides and their 
metabolites to common moieties. Plant and animal metabolism data 
demonstrates that no common metabolites are formed. 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 U.S.A. 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--Adult sub-populations. 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 overall U.S. population and many non-child/infant 
subgroups is 0.000151 to 0.000162 mg/kg bwt/day, 1.5 to 1.6% of the 
cPAD. Addition of the small but worse case potential chronic exposure 
from drinking water (calculated above) increases exposure by 0.0003 mg/
kg bw/day and the maximum occupancy of the cPAD from 1.6% to 4.6%. 
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 overall 
U.S. population and many non-child/infant subgroups from aggregate, 
chronic exposure to clethodim residues.
    i. Acute dietary exposure and risk. An acute dietary endpoint was 
not identified. Thus, the risk from acute aggregate dietary exposure to 
clethodim is considered to be negligible.
    ii. Non-dietary exposure and aggregate risk. Acute, short-term, and 
intermediate-term dermal and inhalation risk assessments for 
residential exposure to clethodim are not required because no 
significant toxicological effects were observed.
    2. Infants and children--i. Safety factor. 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

[[Page 16939]]

safety, up to 10-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 U.S.A. Corporation concludes that 
reliable data support use of the standard 100-fold UF and that an 
additional uncertainty factor is not needed for clethodim to be further 
protective of infants and children.
    ii. Chronic exposure and risk. 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 ranges from 0.7% for 
nursing infants (<1 year old), up to 4.5% for children (1-6 years). 
Adding the worse case potential incremental exposure to infants and 
children from clethodim in drinking water (0.001 mg/kg bwt/day) greatly 
increases the aggregate, chronic dietary exposure and the occupancy of 
the cPAD by 10.0% to 14.5% for children (1-6 years). 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.
    iii. Acute dietary exposure and risk. An acute dietary endpoint was 
not identified. Thus, the risk from acute aggregate dietary exposure to 
clethodim is considered to be negligible.
    iv. Non-dietary exposure and aggregate risk. Acute, short-term, and 
intermediate-term dermal and inhalation risk assessments for 
residential exposure to clethodim are not required because no 
significant toxicological effects were observed.

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 international 
residue limits.
[FR Doc. 01-7640 Filed 3-27-01; 8:45 am]
BILLING CODE 6560-50-S