Document ID: EPA-HQ-OPP-2005-0535-0004
Agency: epa
Document Type: Rule
Title: Clethodim; Pesticide Tolerance
Posted Date: 2007-05-09T04:00Z

[Federal Register: May 9, 2007 (Volume 72, Number 89)]
[Rules and Regulations]               
[Page 26310-26316]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr09my07-12]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2005-0535; FRL-8127-2]

 
Clethodim; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes tolerances for combined residues 
of clethodim and certain of its metabolites in or on asparagus; flax, 
seed; herb, subgroup 19A; hop, dried cones; leafy greens subgroup 4A; 
safflower, meal; safflower, seed; sesame, seed; and vegetable, legume, 
group 6, except soybean. The Interregional Research Project Number 4 
(IR-4) requested these tolerances under the Federal Food, Drug, and 
Cosmetic Act (FFDCA).

DATES: This regulation is effective May 9, 2007. Objections and 
requests for hearings must be received on or before July 9, 2007, and 
must be filed in accordance with the instructions provided in 40 CFR 
part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).

ADDRESSES: EPA has established a docket for this action under docket 
identification (ID) number EPA-HQ-OPP-2005-0535. To access the 
electronic docket, go to http://www.regulations.gov, select ``Advanced 

Search,'' then ``Docket Search.'' Insert the docket ID number where 
indicated and select the ``Submit'' button. Follow the instructions on 
the regulations.gov web site to view the docket index or access 
available documents. All documents in the docket are listed in the 
docket index available in regulations.gov. Although listed in the 
index, some information is not publicly available, e.g., Confidential 
Business Information (CBI) or other information whose disclosure is 
restricted by statute. Certain other material, such as copyrighted 
material, is not placed on the Internet and will be publicly available 
only in hard copy form. Publicly available docket materials are 
available in the electronic docket at http://www.regulations.gov,or, if 

only available in hard copy, at the OPP Regulatory Public Docket in Rm. 
S-4400, One Potomac Yard (South Bldg.), 2777 S. Crystal Dr., Arlington, 
VA. The Docket Facility is open from 8:30 a.m. to 4 p.m., Monday 
through Friday, excluding legal holidays. The Docket telephone number 
is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: Sidney Jackson, Registration Division 
(7505P), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone 
number: (703) 305-7610; e-mail address: jackson.sidney@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

    You may be potentially affected by this action if you are an 
agricultural producer, food manufacturer, or pesticide manufacturer. 
Potentially affected entities may include, but are not limited to those 
engaged in the following activities:
     Crop production (NAICS code 111), e.g., agricultural 
workers; greenhouse, nursery, and floriculture workers; farmers.
     Animal production (NAICS code 112), e.g., cattle ranchers 
and farmers, dairy cattle farmers, livestock farmers.
     Food manufacturing (NAICS code 311), e.g., agricultural 
workers; farmers; greenhouse, nursery, and floriculture workers; 
ranchers; pesticide applicators.
     Pesticide manufacturing (NAICS code 32532), e.g., 
agricultural workers; commercial applicators; farmers; greenhouse, 
nursery, and floriculture workers; residential users.
    This listing is not intended to be exhaustive, but rather to 
provide a guide for readers regarding entities likely to be affected by 
this action. Other types of entities not listed in this unit could also 
be affected. The North American Industrial Classification System 
(NAICS) codes have been provided to

[[Page 26311]]

assist you and others in determining whether this action might apply to 
certain entities. If you have any questions regarding the applicability 
of this action to a particular entity, consult the person listed under 
FOR FURTHER INFORMATION CONTACT.

B. How Can I Access Electronic Copies of this Document?

    In addition to accessing an electronic copy of this Federal 
Register document through the electronic docket at http://www.regulations.gov
, you may access this Federal Register document 

electronically through the EPA Internet under the ``Federal Register'' 
listings at http://www.epa.gov/fedrgstr. You may also access a 

frequently updated electronic version of EPA's tolerance regulations at 
40 CFR part 180 through the Government Printing Office's pilot e-CFR 
site at http://www.gpoaccess.gov/ecfr.

C. Can I File an Objection or Hearing Request?

    Under section 408(g) of the FFDCA, any person may file an objection 
to any aspect of this regulation and may also request a hearing on 
those objections. You must file your objection or request a hearing on 
this regulation in accordance with the instructions provided in 40 CFR 
part 178. To ensure proper receipt by EPA, you must identify docket ID 
number EPA-HQ-OPP-2005-0535 in the subject line on the first page of 
your submission. All requests must be in writing, and must be mailed or 
delivered to the Hearing Clerk as required by 40 CFR part 178 on or 
before July 9, 2007.
    In addition to filing an objection or hearing request with the 
Hearing Clerk as described in 40 CFR part 178, please submit a copy of 
the filing that does not contain any CBI for inclusion in the public 
docket that is described in ADDRESSES. Information not marked 
confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA 
without prior notice. Submit this copy, identified by docket ID number 
EPA-HQ-OPP-2005-0535, by one of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov. 

Follow the on-line instructions for submitting comments.
     Mail: Office of Pesticide Programs (OPP) Regulatory Public 
Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania 
Ave., NW., Washington, DC 20460-0001.
     Delivery: OPP Regulatory Public Docket (7502P), 
Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South 
Bldg.), 2777 S. Crystal Dr., Arlington, VA. Deliveries are only 
accepted during the Docket's normal hours of operation (8:30 a.m. to 4 
p.m., Monday through Friday, excluding legal holidays). Special 
arrangements should be made for deliveries of boxed information. The 
Docket telephone number is (703) 305-5805.

II. Petition for Tolerance

    In the Federal Register of April 21, 2006 (71 FR 20669) (FRL-8056-
8), EPA issued a notice pursuant to section 408(d)(3) of FFDCA, 21 
U.S.C. 346a(d)(3), announcing the filing of pesticide petitions (PP 
3E6555, 5E6977, 4E6836, 5E6978, and 4F6895) by the Interregional 
Research Project 4 (IR-4), 500 College Road East, Suite 201 W, 
Princeton, NJ 08540. The petition requested that 40 CFR 180.458 be 
amended by establishing a tolerance for 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-cyclohexene-1-one 
moiety in or on flax, seed at 0.5 parts per million (ppm) (PP 3E6555); 
herb, subgroup 19A at 10.0 ppm (4E6836); asparagus at 2.0 ppm and hop, 
dried cones at 0.5 ppm (5E6977); leafy greens subgroup 4A at 2.0 ppm 
(5E6978); and sesame, seed at 0.40 ppm; vegetable, legume, group 6 at 
3.0 ppm; safflower, meal at 10.0 ppm; and safflower, seed at 5.0 ppm 
(4F6895). That notice referenced a summary of the petitions prepared by 
Valent U.S.A. Corporation, 133 N. California Blvd., Walnut Creek, CA 
94596, the registrant, which is available to the public in the docket, 
http://www.regulations.gov.

    There were no comments received in response to the notice of 
filing.
    Based upon review of the data supporting the petition, EPA has 
recommended certain changes to the petitions including:
     Revised tolerance levels for certain commodities, and:
     A specific tolerance expression to be applied to all new 
uses in an effort to harmonize tolerances with Codex Maxium Residue 
Limits. The reasons for these changes are explained in Unit V.

III. Aggregate Risk Assessment and Determination of Safety

    Section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a 
tolerance (the legal limit for a pesticide chemical residue in or on a 
food) only if EPA determines that the tolerance is ``safe.'' Section 
408(b)(2)(A)(ii) of the FFDCA defines ``safe'' to mean that ``there is 
a reasonable certainty that no harm will result from aggregate exposure 
to the pesticide chemical residue, including all anticipated dietary 
exposures and all other exposures for which there is reliable 
information.'' This includes exposure through drinking water and in 
residential settings, but does not include occupational exposure. 
Section 408(b)(2)(C) of the FFDCA requires EPA to give special 
consideration to exposure of infants and children to the pesticide 
chemical residue in establishing a tolerance and to ``ensure that there 
is a reasonable certainty that no harm will result to infants and 
children from aggregate exposure to the pesticide chemical residue. . . 
.'' These provisions were added to the FFDCA by the Food Quality 
Protection Act (FQPA) of 1996.
    Consistent with FFDCA section 408(b)(2)(D), and the factors 
specified in section 408(b)(2)(D), EPA has reviewed the available 
scientific data and other relevant information in support of this 
action. EPA has sufficient data to assess the hazards of and to make a 
determination on aggregate exposure for the petitioned for tolerances 
for combined residues of clethodim on flax, seed at 0.6 ppm; herb, 
subgroup 19A at 12.0 ppm (4E6836); asparagus at 1.7 ppm and hop, dried 
cones at 0.5 ppm; leafy greens subgroup 4A at 2.0 ppm (5E6978); and 
sesame, seed at 0.35 ppm; vegetable, legume (except soybean), group 6 
at 3.5 ppm; safflower, meal at 10.0 ppm; and safflower, seed at 5.0 
ppm. EPA's assessment of exposures and risks associated with 
establishing the tolerance follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered their 
validity, completeness, and reliability as well as the relationship of 
the results of the studies to human risk. EPA has also considered 
available information concerning the variability of the sensitivities 
of major identifiable subgroups of consumers, including infants and 
children. Specific information on the studies received and the nature 
of the adverse effects caused by clethodim as well as the no-observed-
adverse-effect-level (NOAEL) and the lowest-observed-adverse-effect-
level (LOAEL) from the toxicity studies can be found at http://www.regulations.gov.
 The referenced document is available in the docket 

established by this action, which is described under ADDRESSES, and is 
identified as ``Clethodim: Human Health Risk Assessment for Proposed 
Uses on Herb Sugbroup 19A, Leafy Greens......and Flax seed, dated 03/
07/2007'' in that docket.

[[Page 26312]]

    Additionally, clethodim toxicological data are discussed in the 
final rule published in the Federal Register of March 14, 2001(66 FR 
14829) (FRL-6770-8).

B. Toxicological Endpoints

    For hazards that have a threshold below which there is no 
appreciable risk, the toxicological level of concern (LOC) is derived 
from the highest dose at which NOAELs are observed in the toxicology 
study identified as appropriate for use in risk assessment. However, if 
a NOAEL cannot be determined, the LOAEL of concern identified is 
sometimes used for risk assessment. Uncertainty/safety factors (UF) are 
used in conjunction with the LOC to take into account uncertainties 
inherent in the extrapolation from laboratory animal data to humans and 
in the variations in sensitivity among members of the human population 
as well as other unknowns. Safety is assessed for acute and chronic 
risks by comparing aggregate exposure to the pesticide to the acute 
population adjusted dose (aPAD) and chronic population adjusted dose 
(cPAD). The aPAD and cPAD are calculated by dividing the LOC by all 
applicable uncertainty/safety factors. Short-term, intermediate-term, 
and long-term risks are evaluated by comparing aggregate exposure to 
the LOC to ensure that the margin of exposure (MOE) called for by the 
product of all applicable uncertainty/safety factors is not exceeded.
    For non-threshold risks, the Agency assumes that any amount of 
exposure will lead to some degree of risk and estimates risk in terms 
of the probability of occurrence of additional adverse cases. 
Generally, cancer risks are considered non-threshold. For more 
information on the general principles EPA uses in risk characterization 
and a complete description of the risk assessment process, see http://www.epa.gov/fedrgstr/EPA-PEST/1997/November/Day-26/p30948.htm
.

    A summary of the toxicological endpoints for clethodim used for 
human risk assessment can be found at http://www.regulations.gov in document 

``Clethodim: Human Health Risk Assessment for Proposed Uses on Herb 
Sugbroup 19A, Leafy Greens......and Flax seed, dated 03/07/2007'' at 
page 14 in Docket ID EPA-HQ-OPP-2005-0535.

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. In evaluating dietary 
exposure to clethodim, EPA considered exposure under the petitioned-for 
tolerances as well as all existing clethodim tolerances in (40 CFR 
180.458). EPA assessed dietary exposures from clethodim in food as 
follows:
    i. Acute exposure. Quantitative acute dietary exposure and risk 
assessments are performed for a food-use pesticide, if a toxicological 
study has indicated the possibility of an effect of concern occurring 
as a result of a 1-day or single exposure. No such effects were 
identified in the toxicological studies for clethodim; therefore, a 
quantitative acute dietary exposure assessment is unnecessary.
    ii. Chronic exposure. In conducting the chronic dietary (food and 
water) exposure assessment, EPA used the food consumption data from the 
U.S. Department of Agriculture's (USDA) Nationwide Continuing Surveys 
of Food Intake by Individuals (CSFII) from 1994-1996 and 1998. The 
chronic dietary exposure assessment was based on the assumption of 
tolerance-level residues for existing and proposed tolerances; and 
incorporated percent crop treated (PCT) information for certain 
registered uses.
    iii. Cancer. Clethodim was negative for carcinogenicity in feeding 
studies in rats and mice and was classified as ``not likely'' to be a 
human carcinogen. Therefore, a quantitative exposure assessment to 
evaluate cancer risk is unnecessary.
    iv. Anticipated residue and PCT information. Section 408(b)(2)(F) 
of FFDCA states that the Agency may use data on the actual percent of 
food treated for assessing chronic dietary risk only if:
    a. The data used are reliable and provide a valid basis to show 
what percentage of the food derived from such crop is likely to contain 
such pesticide residue;
    b. The exposure estimate does not underestimate exposure for any 
significant subpopulation group; and
    c. Data are available on pesticide use and food consumption in a 
particular area, the exposure estimate does not understate exposure for 
the population in such area. In addition, the Agency must provide for 
periodic evaluation of any estimates used. To provide for the periodic 
evaluation of the estimate of PCT as required by section 408(b)(2)(F) 
of FFDCA, EPA may require registrants to submit data on PCT.
    The Agency used PCT information as follows:

----------------------------------------------------------------------------------------------------------------
                 Commodity                               Percent of Crop Treated (Weighted Average)
----------------------------------------------------------------------------------------------------------------
Beets                                                                                                          1
----------------------------------------------------------------------------------------------------------------
Broccoli                                                                                                      10
----------------------------------------------------------------------------------------------------------------
Cabbage                                                                                                        1
----------------------------------------------------------------------------------------------------------------
Cantaloupes                                                                                                    1
----------------------------------------------------------------------------------------------------------------
Carrots                                                                                                       10
----------------------------------------------------------------------------------------------------------------
Celery                                                                                                         5
----------------------------------------------------------------------------------------------------------------
Cotton                                                                                                         1
----------------------------------------------------------------------------------------------------------------
Cucumbers                                                                                                      1
----------------------------------------------------------------------------------------------------------------
Dry beans                                                                                                      5
----------------------------------------------------------------------------------------------------------------
Lettuce                                                                                                        1
----------------------------------------------------------------------------------------------------------------
Onions                                                                                                        10
----------------------------------------------------------------------------------------------------------------
Peanuts                                                                                                        5
----------------------------------------------------------------------------------------------------------------

[[Page 26313]]

Potatoes                                                                                                       5
----------------------------------------------------------------------------------------------------------------
Pumpkins                                                                                                       5
----------------------------------------------------------------------------------------------------------------
Soybeans                                                                                                       5
----------------------------------------------------------------------------------------------------------------
Squash                                                                                                         5
----------------------------------------------------------------------------------------------------------------
Strawberries                                                                                                   1
----------------------------------------------------------------------------------------------------------------
Sugar beets                                                                                                   45
----------------------------------------------------------------------------------------------------------------
Sunflowers                                                                                                    20
----------------------------------------------------------------------------------------------------------------
Sweet potatoes                                                                                                 1
----------------------------------------------------------------------------------------------------------------
Tomatoes                                                                                                       1
----------------------------------------------------------------------------------------------------------------
Watermelons                                                                                                    5
----------------------------------------------------------------------------------------------------------------

    EPA uses an average PCT for chronic dietary risk analysis. The 
average PCT figure for each existing use is derived by combining 
available federal, state, and private market survey data for that use, 
averaging by year, averaging across all years, and rounding up to the 
nearest multiple of five percent except for those situations in which 
the average PCT is less than one. In those cases < 1% is used as the 
average and < 2.5% is used as the maximum. EPA uses a maximum PCT for 
acute dietary risk analysis. The maximum PCT figure is the single 
maximum value reported overall from available federal, state, and 
private market survey data on the existing use, across all years, and 
rounded up to the nearest multiple of five percent. In most cases, EPA 
uses available data from USDA/National Agricultural Statistics Service 
(NASS), Proprietary Market Surveys, and the National Center for Food 
and Agriculture Policy (NCFAP) for the most recent six years.
    The Agency believes that the three conditions listed above have 
been met. With respect to Condition 1, PCT estimates are derived from 
sources as discussed above including Federal and private market survey 
data, which are reliable and have a valid basis. The Agency is 
reasonably certain that the percentage of the food treated is not 
likely to be an underestimation. As to Conditions 2 and 3, regional 
consumption information and consumption information for significant 
subpopulations is taken into account through EPA's computer-based model 
for evaluating the exposure of significant subpopulations including 
several regional groups. Use of this consumption information in EPA's 
risk assessment process ensures that EPA's exposure estimate does not 
understate exposure for any significant subpopulation group and allows 
the Agency to be reasonably certain that no regional population is 
exposed to residue levels higher than those estimated by the Agency. 
Other than the data available through national food consumption 
surveys, EPA does not have available information on the regional 
consumption of food to which clethodim may be applied in a particular 
area.
    2. Dietary exposure from drinking water.The Agency lacks sufficient 
monitoring data to complete a comprehensive dietary exposure analysis 
and risk assessment for clethodim in drinking water. Because the Agency 
does not have comprehensive monitoring data, drinking water 
concentration estimates are made by reliance on simulation or modeling 
taking into account data on the environmental fate characteristics of 
clethodim. Further information regarding EPA drinking water models used 
in pesticide exposure assessment can be found at http://www.epa.gov/oppefed1/models/water/index.htm
.

    Surface water and ground water contamination may occur from the 
sulfoxide and sulfone degradates of clethodim, as well as from parent 
clethodim. However, the risk of water contamination is primarily 
associated with clethodim sulfone and clethodim sulfoxide rather than 
parent clethodim based on greater persistence and mobility for these 
degradates. Parent clethodim may move from the treated field to surface 
water or ground water through run-off or leaching which occurs shortly 
after application (e.g. rainfall). Also, the sulphoxide and sulphone 
degradates may migrate by runoff or leaching for longer periods of time 
since they are more persistent. All residues of clethodim (parent and 
degradates) are very mobile in soil.
    The only significant routes of dissipation of clethodim are 
microbial degradation in soil and movement by leaching or runoff. 
Parent clethodim is moderately persistent to hydrolysis at pH 5 with 
half-lives of 26-42 days and stable at pH 7 and 9 with half-lives 
greater than 300 days. Even though acceptable water and soil photolysis 
studies show half-lives of 1.5 to 9.3 days, this may not be an 
important route of dissipation because of suspended sediment and 
shading. Photolysis is only an important route of dissipation in 
shallow, well-mixed surface water with no shading. The half-lives in 
aerobic soil are 2-3 days for parent clethodim, and 30-38 days for 
total toxic residues (parent + sulphoxide + sulphone). The sulphoxide 
and sulphone metabolites are more persistent than parent clethodim and 
are formed in significant quantities in soil. All residues of clethodim 
(parent and metabolites) are very mobile in soil with five out of six 
soil desorption coefficients (Kd) less than one. The field dissipation 
studies show that parent clethodim was only found at levels at or near 
the quantitation limit of 0.02 ppm, which is consistent with the rapid 
degradation in soil. Clethodim sulphoxide had an apparent half-life of 
2.5 to 3.7 days, indicating that movement from the treated field may 
have been an important route of dissipation.
    In surface water, parent clethodim may move from the treated field 
to surface water or ground water through run-off or leaching which 
occurs shortly after application (e.g. rainfall). Also, the sulphoxide 
and sulphone degradates may migrate by runoff or leaching for longer 
periods of time since they are

[[Page 26314]]

more persistent. All residues of clethodim (parent and degradates) are 
very mobile in soil.
    In ground water, parent clethodim is mobile, but has a short 
metabolic half-life in soil under aerobic conditions. Therefore, parent 
compound should not be a ground water concern in most environments. 
While it is expected that parent clethodim can be transformed to 
sulphoxide or sulphone products quickly by soil metabolism (t[frac12] = 
1 - 3 days), it may be more persistent since it is leached below the 
more biologically active top soil. In such instances (i.e., leaching 
rainfall shortly after application) parent clethodim concentrations may 
be higher than estimated and correspondingly, the concentration of the 
degradates sulphoxide and sulphone would be lower. In the event that 
parent clethodim did reach ground water, the available routes of 
disappearance would be dilution, some metabolism to persistent 
degradates, and slow hydrolysis with the rate depending on the pH of 
the ground water. Estimates are provided for both parent clethodim and 
total toxic clethodim (parent + sulphoxide + sulphone).
    Based on the (FQPA Index Reservoir Screening Tool (FIRST)) model, 
Tier 1 surface water concentrations for parent clethodim and total 
toxic residues (parent + sulphoxide + sulphone) were estimated in 
drinking water. These estimates are based on a maximum application rate 
of 0.5 lb ai/acre per year (2 applications). The peak FIRST estimated 
environmental concentration (EEC) for clethodim and it's degradates, 
sulphoxide and sulphone for acute exposures are estimated to be 38.9 
parts per billion (ppb) for surface water. The EECs for chronic 
exposures are estimated to be 7.6 ppb for surface water. For drinking 
water derived from ground water, the Screening Concentration in Ground 
water (SCI-GROW) model estimates a total toxic clethodim concentration 
of 1.39 ug/L sources were not included, as the EEC's for this water 
source are minimal in comparison to surface water.
    Modeled estimates of drinking water concentrations were directly 
entered into the dietary exposure model. For acute dietary risk 
assessment, the water concentration value of 38.9 ppb was used to 
access the contribution to drinking water. For chronic dietary risk 
assessment, the water concentration of value 7.6 ppb was used to access 
the contribution to drinking water.
    3. From non-dietary exposure. The term ``residential exposure'' is 
used in this document to refer to non-occupational, non-dietary 
exposure (e.g., for lawn and garden pest control, indoor pest control, 
termiticides, and flea and tick control on pets).
    Although clethodim is registered for use in non-crop areas and for 
commercial use on ornamentals, no residential exposure is expected from 
these uses because these uses are clearly intended for commercial and 
institutional applications on commercially grown ornamentals and not 
for ornamentals in a residential setting. Therefore, non-occupational 
exposure assessment of clethodim was not performed.
    4. Cumulative effects from substances with a common mechanism of 
toxicity. Section 408(b)(2)(D)(v) of the FFDCA requires that, when 
considering whether to establish, modify, or revoke a tolerance, the 
Agency consider ``available information'' concerning the cumulative 
effects of a particular pesticide's residues and ``other substances 
that have a common mechanism of toxicity.''
    Unlike other pesticides for which EPA has followed a cumulative 
risk approach based on a common mechanism of toxicity, EPA has not made 
a common mechanism of toxicity finding as to clethodim and any other 
substances and clethodim does not appear to produce a toxic metabolite 
produced by other substances. For the purposes of this tolerance 
action, therefore, EPA has not assumed that clethodim has a common 
mechanism of toxicity with other substances. For information regarding 
EPA's efforts to determine which chemicals have a common mechanism of 
toxicity and to evaluate the cumulative effects of such chemicals, see 
the policy statements released by EPA's Office of Pesticide Programs 
concerning common mechanism determinations and procedures for 
cumulating effects from substances found to have a common mechanism on 
EPA's website at http://www.epa.gov/pesticides/cumulative.

D. Safety Factor for Infants and Children

    1. In general. Section 408 of FFDCA provides that EPA shall apply 
an additional (10X) tenfold margin of safety for infants and children 
in the case of threshold effects to account for prenatal and postnatal 
toxicity and the completeness of the data based on toxicity and 
exposure unless EPA determines based on reliable data that a different 
margin of safety will be safe for infants and children. This additional 
margin of safety is commonly referred to as the FQPA safety factor. In 
applying this provision, EPA either retains the default value of 10X 
when reliable data do not support the choice of a different factor, or, 
if reliable data are available, EPA uses a different additional FQPA 
safety factor value based on the use of traditional uncertainty/safety 
factors and/or special FQPA safety factors, as appropriate.
    2. Prenatal and postnatal sensitivity. There is no evidence of 
susceptibility following in utero and/or postnatal exposure to 
clethodim in the developmental toxicity studies in rats or rabbits, and 
in the 2-generation rat reproduction study.
    There are no residual uncertainties concerning pre- and postnatal 
toxicity and no neurotoxicity concerns.
    3. Conclusion. EPA has determined that reliable data show that it 
would be safe for infants and children to reduce the FQPA safety factor 
to 1X. That decision is based on the following findings:
    i. The toxicity data base for clethodim is complete.
    ii. There is no indication that clethodim is a neurotoxic chemical 
and there is no need for a developmental neurotoxicity study or 
additional uncertainty factors to account for neurotoxicity.
    iii. There is no evidence that clethodim results in increased 
susceptibility in in utero rats or rabbits in the prenatal 
developmental studies or in young rats in the two-generation 
reproduction study.
    iv. There are no residual uncertainties identified in the exposure 
databases. The dietary (food and drinking water) exposure assessment 
will not underestimate the potential exposure for infants, children, 
and/or women of childbearing age. There is no potential for residential 
exposure.

E. Aggregate Risks and Determination of Safety

    Safety is assessed for acute and chronic risks by comparing 
aggregate exposure to the pesticide to the aPAD and cPAD). The aPAD and 
cPAD are calculated by dividing the LOC by all applicable uncertainty/
safety factors. For linear cancer risks, EPA calculates the probability 
of additional cancer cases given aggregate exposure. Short-term, 
intermediate, and long-term risks are evaluated by comparing aggregate 
exposure to the LOC to ensure that the margin of exposure MOE called 
for by the product of all applicable uncertainty/safety factors is not 
exceeded.
    1. Acute risk. There were no effects observed in oral toxicity 
studies including developmental toxicity studies in rats and rabbits 
that could be attributable to a single dose (exposure).

[[Page 26315]]

Therefore, clethodim is not expected to pose an acute risk.
    2. Chronic risk. Using the exposure assumptions described in this 
unit for chronic exposure, EPA has concluded that exposure to clethodim 
from food and water will utilize 29% of the cPAD for the general U.S. 
population group and 84% of the cPAD for children 1-2 years old, the 
subpopulation group with greatest exposure. There are no residential 
uses for clethodim that result in chronic residential exposure to 
clethodim.
    3. Short-term risk. Short-term aggregate exposure takes into 
account residential exposure plus chronic exposure to food and water 
(considered to be a background exposure level).
    Clethodim is not registered for use on any sites that would result 
in residential exposure. Therefore, the aggregate risk is the sum of 
the risk from food and water which do not exceed the Agency's level of 
concern.
    4. Intermediate-term risk. Intermediate-term aggregate exposure 
takes into account residential exposure plus chronic exposure to food 
and water (considered to be a background exposure level).
    Clethodim is not registered for use on any sites that would result 
in residential exposure. Therefore, the aggregate risk is the sum of 
the risk from food and water, which do not exceed the Agency's level of 
concern.
    5. Aggregate cancer risk for U.S. population. Clethodim is 
classified as a ``not likely'' to be carcinogenic in humans based on 
the results of a carcinogenicity study in mice and the combined chronic 
toxicity and carcinogenicity study in the rat. Therefore, clethodim is 
not expected to pose a cancer risk to humans.
    6. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
to the general population, or to infants and children from aggregate 
exposure to clethodim residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    For plants, 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 
commodities that are the subject of this action was RM-26B-3 (a 
modification of RM-26B-2) or RE 45601 (also adapted from Valent (the 
registrant) 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. 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). The concurrent recoveries of clethodim (DME 
and DME-OH) for the submitted trials were generally within the accepted 
range of 70-120%. An exception was the concurrent recovery of DME-OH in 
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.
    For livestock, Analytical Method RM-26B-3 (a modification of RM-
26B-2) has been successfully validated for use with livestock 
commodities and has been submitted to the FDA for publication in PAM 
II.
    IR-4 (petitioner) has previously submitted data 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 sulphoxide, 
and 5-OH clethodim sulphone have been obtained under FDA's multiresidue 
protocols.
    Accordingly, EPA concludes that Adequate enforcement methodology 
(GC/FPD-S) is available to enforce the tolerance expression. The method 
may be requested from: Chief, Analytical Chemistry Branch, 
Environmental Science Center, 701 Mapes Rd., Ft. Meade, MD 20755-5350; 
telephone number: (410) 305-2905; e-mail address: 
residuemethods@epa.gov.

B. International Residue Limits

    There are currently Codex MRLs established for 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, in or on bean, dry 
at 2 ppm; beans, except broad bean and soya bean at 0.5 ppm; field peas 
(dry) at 2 ppm; and soya bean (dry) at 10 ppm. Based on newly submitted 
field trial data, the Agency is establishing a new crop group 
tolerance, i.e., on vegetables, legume, group (crop group 6), except 
soybean. Because the Agency is establishing the tolerances on legume 
vegetables as a crop group, it cannot harmonize the crop group 
tolerance with the varying Codex MRLs for individual legume vegetables.
    There are established Canadian MRLs for clethodim residues and its 
metabolites containing the 2-cyclohex-1-enone moiety on soybean at 10.0 
ppm, beans, 0.5, chickpea at 0.5 ppm; lentils at 0.5 ppm; pea, dry at 
0.5 ppm and flax seed at 0.3 ppm. In addition, Mexican MRLs are 
established for clethodim on bean, kidney at 2.0 ppm and soya bean at 
10 ppm. Harmonization with Canadian and Mexican MRLs is not possible 
based on the MRL calculations of the newly submitted data.

V. Conclusion

    The Agency has revised the proposed tolerance expression to make it 
consistent with the existing tolerance expression in 40 CFR 180.458 
(a)(3). Clethodim is defined as the combined residues of clethodim and 
its metabolites containing the 5-(2-ethylthiopropyl)cyclohexen-3-one 
and 5-(2-ethylthiopropyl)-5-hydroxycyclohexen-3-one moieties and their 
sulphoxides and sulphones. In addition, the Agency revised tolerance 
levels proposed by IR-4 for certain commodities to reflect tolerance 
levels supported by current data bases.
    Therefore, tolerances are established 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 5-(2-
ethylthiopropyl)cyclohexen-3-one and 5-(2-ethylthiopropyl)-5-
hydroxycyclohexen-3-one moieties and their sulphoxides and sulphones in 
or on flax, seed at 0.6 ppm; herb, subgroup 19A at 12.0 ppm; asparagus 
at 1.7 ppm; hop, dried cones at 0.5 ppm; leafy greens subgroup 4A at 
2.0 ppm; and sesame, seed at 0.35 ppm; vegetable, legume group 6, 
except soybean at 3.5 ppm; safflower, meal at 10.0 ppm; and safflower, 
seed at 5.0 ppm.

VI. Statutory and Executive Order Reviews

    This final rule establishes a tolerance under section 408(d) of 
FFDCA in response to a petition submitted to the Agency. The Office of 
Management and Budget (OMB) has exempted these types of actions from 
review under Executive Order 12866, entitled Regulatory Planning and 
Review (58 FR 51735, October 4, 1993). Because this rule has been 
exempted from review under Executive Order 12866, this rule is not

[[Page 26316]]

subject to Executive Order 13211, Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use (66 FR 28355, 
May 22, 2001) or Executive Order 13045, entitled Protection of Children 
from Environmental Health Risks and Safety Risks (62 FR 19885, April 
23, 1997). This final rule does not contain any information collections 
subject to OMB approval under the Paperwork Reduction Act (PRA), 44 
U.S.C. 3501 et seq., nor does it require any special considerations 
under Executive Order 12898, entitled Federal Actions to Address 
Environmental Justice in Minority Populations and Low-Income 
Populations (59 FR 7629, February 16, 1994).
    Since tolerances and exemptions that are established on the basis 
of a petition under section 408(d) of FFDCA, such as the tolerance in 
this final rule, do not require the issuance of a proposed rule, the 
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et 
seq.) do not apply.
    This final rule directly regulates growers, food processors, food 
handlers and food retailers, not States or tribes, nor does this action 
alter the relationships or distribution of power and responsibilities 
established by Congress in the preemption provisions of section 
408(n)(4) of FFDCA. As such, the Agency has determined that this action 
will not have a substantial direct effect on States or tribal 
governments, on the relationship between the national government and 
the States or tribal governments, or on the distribution of power and 
responsibilities among the various levels of government or between the 
Federal Government and Indian tribes. Thus, the Agency has determined 
that Executive Order 13132, entitled Federalism (64 FR 43255, August 
10, 1999) and Executive Order 13175, entitled Consultation and 
Coordination with Indian Tribal Governments (65 FR 67249, November 6, 
2000) do not apply to this rule. In addition, This rule does not impose 
any enforceable duty or contain any unfunded mandate as described under 
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA) (Public Law 
104-4).
    This action does not involve any technical standards that would 
require Agency consideration of voluntary consensus standards pursuant 
to section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (NTTAA), Public Law 104-113, section 12(d) (15 U.S.C. 272 
note).

VII. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report to each House of the Congress and to 
the Comptroller General of the United States. EPA will submit a report 
containing this rule and other required information to the U.S. Senate, 
the U.S. House of Representatives, and the Comptroller General of the 
United States prior to publication of this final rule in the Federal 
Register. This final rule is not a ``major rule'' as defined by 5 
U.S.C. 804(2).

List of Subjects in 40 CFR Part 180

    Environmental protection, Administrative practice and procedure, 
Agricultural commodities, Pesticides and pests, Reporting and 
recordkeeping requirements.

    Dated: May 1, 2007.
Lois Rossi,
Director, Registration Division, Office of Pesticide Programs.

0
Therefore, 40 CFR chapter I is amended as follows:

PART 180--[AMENDED]

0
1. The authority citation for part 180 continues to read as follows:

    Authority: 21 U.S.C. 321(q), 346a and 371.

0
2. Section 180.458 is amended by alphabetically adding the following 
commodities to the table in paragraph (a)(3) to read as follows:

Sec.  180.458  Clethodim; tolerances for residues.

    (a) * * *
    (3) * * *

------------------------------------------------------------------------
                   Commodity                        Parts per million
------------------------------------------------------------------------
Asparagus......................................                      1.7
------------------------------------------------------------------------
                                * * * * *
Flax seed......................................                      0.6
------------------------------------------------------------------------
                                * * * * *
Herb subgroup 19A..............................                     12.0
------------------------------------------------------------------------
                                * * * * *
Hop, dried cones...............................                      0.5
------------------------------------------------------------------------
                                * * * * *
Leafy greens subgroup 4A.......................                      2.0
------------------------------------------------------------------------
                                * * * * *
Safflower, meal................................                     10.0
------------------------------------------------------------------------
Safflower, seed................................                      5.0
------------------------------------------------------------------------
Sesame, seed...................................                     0.35
------------------------------------------------------------------------
                                * * * * *
Vegetable, legume group 6, except soybean......                      3.5
------------------------------------------------------------------------

* * * * *
[FR Doc. E7-8938 Filed 5-8-07; 8:45 am]

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