Document ID: EPA-HQ-OPP-2006-0321-0003
Agency: epa
Document Type: Rule
Title: Sethoxydim; Pesticide Tolerance
Posted Date: 2007-02-28T05:00Z

[Federal Register: February 28, 2007 (Volume 72, Number 39)]
[Rules and Regulations]               
[Page 8916-8923]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr28fe07-9]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2006-0321; FRL-8115-8]

 
Sethoxydim; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes tolerances for combined residues 
of sethoxydim {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-
hydroxy-2-cyclohexen-1-one {time} and its metabolites containing the 2-
cyclohexen-1-one moiety (calculated as sethoxydim) in or on buckwheat 
grain, buckwheat flour, okra, borage seed, borage meal, fresh dillweed 
leaves, radish tops, turnip greens, and vegetable, root and tuber, 
group 1. Interregional Research Project No. 4 (IR-4) requested these 
tolerances under the Federal Food, Drug, and Cosmetic Act (FFDCA), as 
amended by the Food Quality Protection Act of 1996 (FQPA).

DATES: This regulation is effective February 28, 2007. Objections and 
requests for hearings must be received on or before April 30, 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-2006-0321. All documents in the 
docket are listed in the index for the docket. 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 Building), 2777 S. Crystal Drive, 
Arlington, VA. The Docket Facility is open from 8:30 a.m. to 4 p.m., 
Monday through Friday,

[[Page 8917]]

excluding legal holidays. The Docket telephone number is (703) 305-
5805.

FOR FURTHER INFORMATION CONTACT: Barbara Madden, Registration Division 
(7505P), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone 
number: (703) 305-6463; e-mail address: Madden.Barbara@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:
     Crop production (NAICS 111), e.g., agricultural workers; 
greenhouse, nursery, and floriculture workers; farmers.
     Animal production (NAICS 112), e.g., cattle ranchers and 
farmers, dairy cattle farmers, livestock farmers.
     Food manufacturing (NAICS 311), e.g., agricultural 
workers; farmers; greenhouse, nursery, and floriculture workers; 
ranchers; pesticide applicators.
     Pesticide manufacturing (NAICS 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 provides 
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 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 40 CFR part 180 through the 
Government Printing Office's pilot e-CFR site at http://www.gpoaccess.gov/ecfr.
 To access the OPPTS Harmonized Guidelines 

referenced in this document, go directly to the guidelines at http://www.epa.gpo/opptsfrs/home/guidelin.htm
.

C. Can I File an Objection or Hearing Request?

    Under section 408(g) of the FFDCA, as amended by the FQPA, any 
person may file an objection to any aspect of this regulation and may 
also request a hearing on those objections. The EPA procedural 
regulations which govern the submission of objections and requests for 
hearings appear in 40 CFR part 178. 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-2006-0321 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 on or 
before April 30, 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 your copies, identified by docket ID 
number EPA-HQ-OPP-2006-0321, 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 
Building), 2777 S. Crystal Drive, 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. Background and Statutory Findings

    In the Federal Register of July 5, 2006 (71 FR 38154) (FRL-8074-7), 
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 0E6204 and 
4E6885) by IR-4, 500 College Road East, Suite 201 W, Princeton, NJ 
08540. The petitions requested that 40 CFR 180.412 be amended by 
establishing tolerances for combined residues of the herbicide 
sethoxydim {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-
2-cyclohexen-1-one{time}  and its metabolites containing the 2-
cyclohexen-1-one moiety in or on turnip tops at 5.0 parts per million 
(ppm) (PP 0E6204) and buckwheat, grain at 20 ppm; buckwheat, flour at 
20 ppm; borage; seed at 5.0 ppm; borage, meal at 40 ppm; borage, oil at 
40 ppm; dill, fresh leaves at 10 ppm; dill, dried leaves at 10 ppm; 
okra at 4.0 ppm; vegetable root, except sugar beet, group 1B at 4.0 
ppm; and radish tops at 5.0 ppm (4E6885). That notice referenced a 
summary of the petition prepared by BASF Corporation, the registrant, 
that is available in EPA's electronic docket. There were no comments 
received in response to the notice of filing.
    Upon completing review of the current sethoxydim database, the 
Agency concluded that the appropriate tolerance levels and preferred 
commodity terms for sethoxydim residues in or on pending crops should 
be established as follows: Buckwheat, grain at 19 ppm; buckwheat, flour 
at 25 ppm; okra at 2.5 ppm; borage, seed at 6.0 ppm; borage, meal at 10 
ppm; dillweed, fresh leaves at 10 ppm; radish, tops at 4.5 ppm; turnip, 
greens at 5.0 ppm and Vegetable, root and tuber, group 1 at 4.0 ppm. 
Vegetable, root and tuber, group 1 incorporates both the request for 
vegetable root, except sugar beet, group 1B at 4.0 ppm and existing 
tolerances for carrot, roots at 1.0 ppm; horseradish at 4.0 ppm; beet, 
garden at 1.0 ppm; beet, sugar, root at 1.0 ppm; and tuberous and corm 
vegetable subgroup 1D at 4.0 ppm. Turnip, greens replaces the term 
turnip tops. In addition, the proposed tolerance for borage oil was 
withdrawn because no separate tolerance is required since oil is 
covered by the borage seed tolerance and the proposed tolerance for 
dill, dried leaves was withdrawn because no separate tolerance is 
required since dried dillweed is covered by the fresh dillweed 
tolerance.
    EPA is also deleting several established tolerances in section 
180.412(a) that are no longer needed as a result of this action. The 
revisions to section 180.412(a) are as follows: Delete beet, garden at 
1.0 ppm; beet, sugar, roots at 1.0 ppm; carrot, roots at 1.0 ppm; 
horseradish at 4.0 ppm; and tuberous and corm vegetable crop subgroup 
at 4.0 ppm. All of these tolerances are replaced with vegetable, root 
and tuber, group 1 at 4.0 ppm.
    Section 408(b)(2)(A)(i) of FFDCA allows EPA to establish a 
tolerance (the

[[Page 8918]]

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 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 
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. . . .''
    EPA performs a number of analyses to determine the risks from 
aggregate exposure to pesticide residues. For further discussion of the 
regulatory requirements of section 408 of the FFDCA and a complete 
description of the risk assessment process, see http://www.epa.gov/fedrgstr/EPA-PEST/1997/November/Day-26/p30948.htm and http://

://

III. Aggregate Risk Assessment and Determination of Safety

    Consistent with section 408(b)(2)(D) of FFDCA, 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, consistent with section 
408(b)(2) of FFDCA, for tolerances for combined residues of sethoxydim 
and its metabolites containing the 2-cyclohexen-1-one moiety on 
buckwheat, grain at 19 ppm; buckwheat, flour at 25 ppm; okra at 2.5 
ppm; borage, seed at 6.0 ppm; borage, meal at 10 ppm; dillweed, fresh 
leaves at 10 ppm; radish, tops at 4.5 ppm; turnip, greens at 5.0 ppm 
and vegetable, root and tuber, group 1 at 4.0 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 its 
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 toxic effects caused by sethoxydim as well as the no-observed-
adverse-effect-level (the NOAEL) and the lowest-observed-adverse-
effect-level (the LOAEL) from the toxicity studies can be found in the 
final rule published in the Federal Register of September 29, 2003 (68 
FR 55858) (http://www.epa.gov/EPA-PEST/2003/September/Day-29/p24562.htm
).

B. Toxicological Endpoints

    For hazards that have a threshold below which there is no 
appreciable risk, the dose at which the (NOAEL) from the toxicology 
study identified as appropriate for use in risk assessment is used to 
estimate the toxicological level of concern (LOC). However, the (LOAEL) 
of concern are identified is sometimes used for risk assessment if no 
NOAEL was achieved in the toxicology study selected. An uncertainty 
factor (UF) is applied to reflect 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.
    The linear default risk methodology (Q*) is the primary method 
currently used by the Agency to quantify non-threshold hazards such as 
cancer. The Q* approach assumes that any amount of exposure will lead 
to some degree of cancer risk, estimates risk in terms of the 
probability of occurrence of additional cancer cases. More information 
can be found on the general principles EPA uses in risk 
characterization at be found on the general principles EPA uses in risk 
characterization at http://www.epa.gov/pesticides/health/human.htm.

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

0003 (page 9) in Docket ID EPA-HQ-OPP-2006-0321. To locate this 
information on the Regulations.gov website follow these steps:
    Select ``Advanced Search'', then ``Docket Search.''
    In the ``Keyword'' field type the chemical name or insert the 
applicable ``Docket ID number.'' (example: EPA-HQ-OPP-2005-9999).
    Click the ``Submit''button.
    Follow the instructions on the regulations.gov web site to view the 
index for the docket and access available documents.

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. Tolerances have been 
established (40 CFR 180.412) for the combined residues of sethoxydim 
and its 2-cyclohexen-1-one moiety containing metabolites, in or on a 
variety of raw agricultural commodities. Tolerances have also been 
established for combined residues of sethoxydim in or on milk, egg, and 
fat, meat, and meat byproducts of cattle, goat, hog, horse, poultry and 
sheep. Risk assessments were conducted by EPA to assess dietary 
exposures from sethoxydim 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 one-day or single exposure.
    In conducting the acute dietary exposure assessment EPA used the 
Dietary Exposure Evaluation Model software with the Food Commodity 
Intake Database (DEEM-FCID\TM\), which incorporates food consumption 
data as reported by respondents in the USDA 1994-1996 and 1998 
Nationwide Continuing Surveys of Food Intake by Individuals (CSFII), 
and accumulated exposure to the chemical for each commodity. The 
following assumptions were made for the acute exposure assessments: For 
all proposed new uses and for all commodities in Vegetable, root and 
tuber, group 1, tolerance level residues and 100 percent crop treated 
(PCT) were assumed. For the remaining crops with existing tolerances 
available maximum PCT values were used. Tolerance level residues were 
assumed for most crops except for grapes, oranges, potatoes, tomatoes, 
strawberries, apples, pears and other pome fruits where anticipated 
residues were calculated through the incorporation of field trial data. 
Empirical processing data for apples, grapes, tomatoes, potatoes and 
oranges were used, and were sometimes translated to other members of 
the crop group. For livestock commodities, the available PCT 
information was incorporated into the dietary burden calculation and 
the feeding studies were used to determine the appropriate residue 
level, however at least one food item in each diet was assumed to be 
100 PCT. PCT information was incorporated into the acute exposure and 
risk assessments through use of probabilistic risk assessment model.
    ii. Chronic exposure. In conducting the chronic dietary exposure 
assessment EPA used the DEEM\TM\ software with the Food Commodity 
Intake Database, which incorporates food consumption data as reported 
by respondents in the United States Department of Agriculture

[[Page 8919]]

(USDA) 1994-1996 and 1998 Nationwide Continuing Surveys of Food Intake 
by Individuals (CSFII), and accumulated exposure to the chemical for 
each commodity. The following assumptions were made for the chronic 
exposure assessments: For the proposed new uses and all commodities in 
Vegetable, root and tuber, group 1 tolerance level residues and 100% CT 
were assumed. For most of the crops with existing tolerances, tolerance 
level residues and average PCT values were assumed. PCT data for some 
livestock feeds were incorporated into the calculations of the 
theoretical dietary burdens for livestock, which were then used in 
conjunction with the available feeding studies to determine the 
anticipated residues in livestock commodities.
    iii. Cancer. The Agency has classified sethoxydim as not likely to 
be a human carcinogen based on lack of evidence of carcinogenicity in 
rats and mice. Therefore, a cancer dietary exposure assessment was not 
performed
    iv. Anticipated residue and PCT information. Section 408(b)(2)(E) 
of the FFDCA authorizes EPA to use available data and information on 
the anticipated residue levels of pesticide residues in food and the 
actual levels of pesticide chemicals that have been measured in food. 
If EPA relies on such information, EPA must pursuant to section 
408(f)(1) require that data be provided 5 years after the tolerance is 
established, modified, or left in effect, demonstrating that the levels 
in food are not above the levels anticipated. Following the initial 
data submission, EPA is authorized to require similar data on a time 
frame it deems appropriate. For the present action, EPA will issue such 
Data Call-Ins for information relating to anticipated residues as are 
required by FFDCA section 408(b)(2)(E) and authorized under FFDCA 
section 408(f)(1). Such Data Call-Ins will be required to be submitted 
no later than 5 years from the date of issuance of this tolerance.
    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 the Agency can make the following findings: Condition 1, 
that 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; Condition 2, that the exposure estimate does not 
underestimate exposure for any significant subpopulation group; and 
Condition 3, if 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 for the chronic dietary risk 
assessment as follows: 1% apples, 1% apricots, 6% globe artichokes, 5% 
asparagus, 14% dry beans, 9% lima beans, 8% snap beans, 5% garden beet 
tops, 1% broccoli, 5% cabbage, 8% cantaloupes, 2% cauliflower, 1% 
cherries, 2% collards, 1% corn, 1% cotton, 8% cranberries, 6% 
cucumbers, 5% eggplants, 38% flax, 1% grapes, 1% grapefruits, 5% 
lemons, 1% lettuce, 1% nectarines, 3% oranges, 2% succulent peas, 14% 
dry peas, 1% peaches, 5% peanuts, 1% pears, 3% bell peppers, 6% nonbell 
peppers, 4% potatoes, 8% pumpkins, 4% rapeseed, 6% rhubarb, 2% 
soybeans, 1% spinach, 8% summer squash, 5% strawberry, 14% sunflower, 
4% tomatoes, 5% turnip greens, and 12% watermelons.
    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 United States Department of Agriculture/
National Agricultural Statistics Service (USDA/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 III.C.1.iv. 
have been met. With respect to Condition 1, PCT estimates are derived 
from 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 sethoxydim may 
be applied in a particular area.
    2. Dietary exposure from drinking water. The Agency lacks 
sufficient monitoring exposure data to complete a comprehensive dietary 
exposure analysis and risk assessment for sethoxydim 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 physical 
characteristics of sethoxydim. 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.

    Based on the First Index Screening Tool Reservoir (FIRST) and 
Screening Concentration in Groundwater (SCI-GROW) models, the estimated 
environmental concentrations (EECs) of sethoxydim for acute exposures 
are estimated to be 130 parts per billion (ppb) for surface water and 
1.5 ppb for ground water. The EECs for chronic exposures are estimated 
to be 16 ppb for surface water and 1.5 ppb for ground 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 130 ppb was used to assess 
the contribution to drinking water. For chronic dietary risk 
assessment, the water concentration value of 16 ppb was used to assess 
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).
    Sethoxydim is currently registered for use on the following 
residential non-dietary sites: Ornamentals and flowering

[[Page 8920]]

plants, recreational areas, rights-of-way, along fences and hedgerows, 
and public and commercial buildings/structures (non-agricultural-
outdoors). The risk assessment was conducted using the following 
residential exposure assumptions: Homeowners who apply sethoxydim to 
ornamental gardens and turf may be exposed for short-term (up to 30 
days) durations via the dermal and inhalation routes. Short-term post 
application exposures to children may result from incidental oral 
contact via hand-to-mouth, turf-to-mouth, and soil-to-mouth activities 
with treated turf. No dermal toxicity endpoints were identified, 
therefore, only exposure from inhalation (adult handlers) and 
incidental ingestion (children) were assessed. For short-term and 
intermediate-term aggregate exposure, the inhalation exposures 
estimated for adult handlers cannot be combined with dietary exposure 
due to lack of common toxicity via the oral [transitory clinical signs: 
Irregular gait at doses of 650 milligrams/kilogram (mg/kg) and 1,000 
mg/kg and inhalation (hepatotoxicity)] routes of exposure. Therefore, 
only short-term aggregate exposures from incidental ingestion for 
children via hand-to-mouth, turf-to-mouth, and soil-to-mouth activities 
with treated turf were assessed.
    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 sethoxydim and any other 
substances and sethoxydim 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 sethoxydim 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 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 base on toxicity and exposure 
unless EPA determines based on reliable data that a different margin of 
safety will be safe for infants and children. Margins of safety are 
incorporated into EPA risk assessments either directly through use of a 
MOE analysis or through using uncertainty (safety) factors in 
calculating a dose level that poses no appreciable risk to humans. 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 safety 
factor value based on the use of traditional uncertainty factors and/or 
special FQPA safety factors, as appropriate.
    2. Prenatal and postnatal sensitivity. Since there is evidence of 
increased susceptibility of the young following exposure to sethoxydim 
in the rat developmental study and the rat reproduction study, the EPA 
performed a Degree of Concern Analysis to: 1. Determine the level of 
concern for the effects observed when considered in the context of all 
available toxicity data; and 2. Identify any residual uncertainties 
after establishing toxicity endpoints and traditional uncertainty 
factors to be used in the risk assessment of this chemical. If residual 
uncertainties are identified, EPA examines whether these residual 
uncertainties can be addressed by a special FQPA safety factor and, if 
so, the size of the factor needed. The results of Degree of Concern 
analysis for sethoxydim are presented as follows:
    The degree of concern is low for the fetal effects in the 
developmental rat study since the fetal anomalies were seen only at the 
high dose (650 mg/kg/day) which is close to the Limit Dose (1,000 mg/
kg/day), they were seen in the presence of maternal toxicity (irregular 
gait) and clear NOAELs/LOAELs were established for maternal and 
developmental toxicities.
    EPA has determined that the degree of concern was low for prenatal 
and/or postnatal toxicity resulting from exposure to sethoxydim 
toxicity.
    3. Conclusion. In the final rule published in the Federal Register 
of September 29, 2003 (68 FR 55858) (FRL-7328-6) (http://www.epa.gov/EPA-PEST/2003/September/Day-29/p24562.htm
). EPA retained the additional 

10X FQPA safety factor in the form of a Data base Uncertainty Factor 
because EPA had required submission of subchronic and developmental 
neurotoxicity studies due to various clinical signs in the rat 
developmental study and evidence of developmental abnormalities in the 
rat developmental and reproductive studies. In December of 2004, the 
EPA revisited the requirement for the subchronic and developmental 
neurotoxicity studies and determined that the evidence does not support 
the need for neurotoxicity studies for the reasons discussed below.
    First, EPA concluded that the clinical signs seen in the rat 
developmental study were not neurotoxicity. The clinical signs 
following sethoxydim exposure in that study were irregular gait, 
decreased activity, excessive salivation, and anogenital staining. 
These effects were only observed in animals receiving very high doses 
of sethoxydim (650 mg/kg/day and 1,000 mg/kg/day). Irregular gait was 
observed in 12/24 dams at 650 mg/kg/day and 10/10 dams at 1,000 mg/kg/
day on the first day of dosing, after 3 doses the signs began to 
dissipate. Decreased activity was noted in 1/34 dams at 650 mg/kg/day 
and in 4/10 dams at 1,000 mg/kg/day and reversed after several days. 
Excessive salivation was noted in 23/34 dams at 650 mg/kg/day and 10/10 
dams at 1,000 mg/kg/day. Anogenital staining was documented in 13/34 
dams at 650 mg/kg/day and 7/10 dams at 1,000 mg/kg/day. All clinical 
signs reported were transient, with the exception of the anogenital 
staining which did not reverse. Because the clinical signs occurred 
shortly after dosing, only occurred at very high treatment doses (over 
one half the limit dose) and were transitory, it is unlikely that the 
signs observed are the result of a primary systemic effect on the 
nervous system but, rather, are reflective of the general toxicity at 
the high dose. It should be noted that clinical signs indicative of 
nervous system effects were not observed in any other standard toxicity 
study for sethoxydim. Although none of these other studies dosed up to 
650 and 1,000 mg/kg/day, a maximum tested dose was reached because of 
evidence of other toxicities (e.g., liver effects or body weight 
reductions).
    Second, EPA found that there were no developmental effects seen in 
the rat and rabbit prenatal studies indicative of an effect on the 
nervous system. The main effect seen in the rat and rabbit prenatal 
studies was an increased incidence of fetal skeletal variations due

[[Page 8921]]

to delayed ossification. In the rat prenatal study, tail abnormalities 
(filamentous tail or lack of a tail) were noted. These abnormalities 
were observed at a very low incidence (10 fetuses in 7 litters, 650 
milligrams/kilogram/body weight/day (mg/kg/bwt/day and at high 
treatment doses (650 and 1,000 mg/kg/day). In the 2-generation 
reproduction study in rat, a tail anomaly (short, thread-like tail, no 
anal opening, hindlimbs curved toward central midline) was found in one 
pup in the F2b generation (1/344 total pups; in 1/4 litters). Tail 
abnormalities are sometimes thought to relate to central nervous system 
(CNS) malformations; however, in this case, these tail abnormalities 
are not likely to be the result of a primary neurotube effect. In the 
rat prenatal study, there is no description of any effect on neural 
tube derived structures. Furthermore, the class of compounds, 
cyclohexones (which sethoxydim is a member), do not demonstrate 
neurotoxicity or developmental malformations of the nervous system.
    Therefore, after a weight-of-evidence examination of all the 
toxicological studies available in the data base, the previous 
requirement for a neurotoxicity studies have been waived.
    In light of its finding that neurotoxicity studies are not needed, 
EPA has now 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:
    1. The toxicity database for sethoxydim is complete.
    2. There is no indication that sethoxydim is a neurotoxic chemical 
and there is no need for a developmental neurotoxicity study or 
additional uncertainty factors to account for neurotoxicity.
    3. Although there is qualitative evidence of increased 
susceptibility in the prenatal developmental studies in rats and 
rabbits, the risk assessment team did not identify any residual 
uncertainties after establishing toxicity endpoints and traditional 
uncertainty factors to be used in the risk assessment for sethoxydim. 
The degree of concern for pre-and/or postnatal toxicity is low.
    4. There are no residual uncertainties identified in the exposure 
databases. The dietary food exposure assessments were performed based 
on tolerance level residues and 100 PCT for all proposed new uses and 
for all commodities in Vegetable, root and tuber, group 1. For most of 
the remaining crops available maximum PCT treated values were used for 
acute dietary assessment and average PCT values were assumed for 
chronic dietary assessment. Tolerance level residues were assumed for 
crops with existing tolerances or anticipated residues were calculated 
through the incorporation of field trial data. Conservative ground and 
surface water modeling estimates were used. Similarly conservative 
Residential SOPs were used to assess post-application exposure to 
children as well as incidental oral exposure of toddlers. These 
assessments will not underestimate the exposure and risks posed by 
sethoxydim.

E. Aggregate Risks and Determination of Safety

    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. 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. Using the exposure assumptions discussed in this 
unit for acute exposure, the acute dietary exposure from food and water 
to sethoxydim will occupy 11% of the aPAD for the U.S. population, 7.2% 
of the aPAD for females 13 years and older, 14% of the aPAD for all 
infants (< 1 year old), and 20% of the aPAD for children 1-2 years old, 
the subpopulation at greatest exposure
    2. Chronic risk. Using the exposure assumptions described in this 
unit for chronic exposure, EPA has concluded that exposure to 
sethoxydim from food and water will utilize 6.9% of the cPAD for the 
U.S. population, 15% of the cPAD for all infants (< 1 year old), and 16% 
of the cPAD for children 1-2 years old, the subpopulation at greatest 
exposure. Based on the use pattern, chronic residential exposure to 
residues of sethoxydim is not expected.

    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). Sethoxydim is currently 
registered for use that could result in short-term residential exposure 
and the Agency has determined that it is appropriate to aggregate 
chronic food and water and short-term exposures for sethoxydim.
    Using the exposure assumptions described in this unit for short-
term exposures, EPA has concluded that food, water and residential 
exposures aggregated result in aggregate MOEs of 5,700 for children/
toddlers 1-2 years of age. Since this is the subpopulation with the 
highest estimated food and water exposures and the calculated MOE of 
5,700 is substantially greater than the target MOE of 100 EPA has no 
concern for short-term aggregate risk for other subpopulations as well.
    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).
    Though residential exposure could occur with the use of sethoxydim 
intermediate-term exposures are not expected. Only risks associated 
with short-term exposures of up to 30 days were assessed.
    5. Aggregate cancer risk for U.S. population. The Agency has 
classified sethoxydim as not likely to be a human carcinogen based on 
lack of evidence of carcinogenicity in rats and mice. Sethoxydim is not 
expected to pose a cancer risk.
    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, and to infants and children from aggregate 
exposure to sethoxydim residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    Adequate enforcement methodology (gas-liquid chromatography with 
flame photometric detection in the sulfur mode) is available BASF 
Wyandotte Corporations' (BWCs) Method No. 30, 3/15/82; MRID 44864501; 
Method I, PAM II to enforce the tolerance expression for the purpose of 
this request.

B. International Residue Limits

    There are currently no Codex maximum residue levels for sethoxydim.

V. Conclusion

    Therefore, the tolerance is established for combined residues of 
sethoxydim {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-
2-cyclohexen-1-one{time} and its metabolites containing the 2-
cyclohexen-1-one moiety (calculated as sethoxydim), in or on buckwheat, 
grain at 19 ppm; buckwheat, flour at 25 ppm; okra at 2.5 ppm; borage, 
seed at 6.0 ppm; borage, meal at 10 ppm; dillweed, fresh leaves

[[Page 8922]]

at 10 ppm; radish, tops at 4.5 ppm; turnip, greens at 5.0 ppm and 
vegetable, root and tuber, group 1 at 4.0 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 due to its lack of 
significance, this rule is not subject to Executive Order 13211, 
Actions Concerning Regulations That Significantly Affect Energy Supply, 
Distribution, or Use (66 FR 28355, May 22, 2001). 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., or 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). 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); or OMB review or any Agency action under Executive 
Order 13045, entitled Protection of Children from Environmental Health 
Risks and Safety Risks (62 FR 19885, April 23, 1997). 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). 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. In addition, the Agency has determined that this 
action will not have a substantial direct effect on States, on the 
relationship between the national government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government, as specified in Executive Order 13132, entitled Federalism 
(64 FR 43255, August 10, 1999). Executive Order 13132 requires EPA to 
develop an accountable process to ensure ``meaningful and timely input 
by State and local officials in the development of regulatory policies 
that have federalism implications.'' ``Policies that have federalism 
implications'' is defined in the Executive Order to include regulations 
that have ``substantial direct effects on the States, on the 
relationship between the national government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government.'' This final rule directly regulates growers, food 
processors, food handlers and food retailers, not States. This action 
does not alter the relationships or distribution of power and 
responsibilities established by Congress in the preemption provisions 
of section 408(n)(4) of FFDCA. For these same reasons, the Agency has 
determined that this rule does not have any ``tribal implications'' as 
described in Executive Order 13175, entitled Consultation and 
Coordination with Indian Tribal Governments (65 FR 67249, November 6, 
2000). Executive Order 13175, requires EPA to develop an accountable 
process to ensure ``meaningful and timely input by tribal officials in 
the development of regulatory policies that have tribal implications.'' 
``Policies that have tribal implications'' is defined in the Executive 
Order to include regulations that have ``substantial direct effects on 
one or more Indian tribes, on the relationship between the Federal 
Government and the Indian tribes, or on the distribution of power and 
responsibilities between the Federal Government and Indian tribes.'' 
This rule will not have substantial direct effects on tribal 
governments, on the relationship between the Federal Government and 
Indian tribes, or on the distribution of power and responsibilities 
between the Federal Government and Indian tribes, as specified in 
Executive Order 13175. Thus, Executive Order 13175 does not apply to 
this rule.

VII. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
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: February 13, 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 180.412 is amended in paragraph (a), in the table, by 
removing the commodities ``Beet, garden'', ``Beet, sugar, roots'', 
``Carrot, roots'' ``Horseradish'', and ``Tuberous and corm vegetable 
crop subgroup''; and alphabetically adding commodities to read as 
follows:

Sec. 180.412  Sethoxydim: Tolerances for residues.

    (a) * * *

------------------------------------------------------------------------
              Commodity                        Parts per million
------------------------------------------------------------------------
                                * * * * *
Borage, meal........................                                  10
Borage, seed........................                                 6.0
Buckwheat, flour....................                                  25
Buckwheat, grain....................                                  19
                                * * * * *
Dillweed, fresh leaves..............                                  10
                                * * * * *
Okra................................                                 2.5

[[Page 8923]]

                                * * * * *
Radish, tops........................                                 4.5
                                * * * * *
Turnip, greens......................                                 5.0
                                * * * * *
Vegetable, root and tuber, group 1..                                 4.0
------------------------------------------------------------------------

[FR Doc. E7-3010 Filed 2-27-07; 8:45 am]

BILLING CODE 6560-50-S