Document ID: EPA-HQ-OPP-2009-0009-0004
Agency: epa
Document Type: Rule
Title: Pesticide Tolerances: Chlorimuron Ethyl
Posted Date: 2009-12-18T05:00Z

[Federal Register: December 18, 2009 (Volume 74, Number 242)]
[Rules and Regulations]               
[Page 67082-67088]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr18de09-7]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2009-0009; FRL-8798-1]

 
Chlorimuron Ethyl; Pesticide Tolerances

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes tolerances for residues of 
chlorimuron ethyl, including its metabolites and degradates, in or on 
corn, field, forage; corn, field grain; corn, field, stover; grain, 
aspirated fractions; soybean, forage; and soybean, hay. In addition, 
the presently established tolerance term, ``soybean'' is being revised 
to ``soybean, seed.'' E.I. du Pont de Nemours and Company requested 
these tolerances under the Federal Food, Drug, and Cosmetic Act 
(FFDCA).

DATES: This regulation is effective December 18, 2009. Objections and 
requests for hearings must be received on or before February 16, 2010, 
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-2009-0009. All documents in the 
docket are listed in the docket index available at http://
www.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 Facility telephone number is (703) 
305-5805.

FOR FURTHER INFORMATION CONTACT: Beth Benbow, Registration Division 
(7505P), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone 
number: (703) 347-8072; e-mail address: benbow.bethany@epa.gov.

[[Page 67083]]

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).
     Animal production (NAICS code 112).
     Food manufacturing (NAICS code 311).
     Pesticide manufacturing (NAICS code 32532).
    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 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 electronically available documents 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 e-CFR cite 
at http://www.gpoaccess.gov/ecfr.

C. Can I File an Objection or Hearing Request?

    Under section 408(g) of FFDCA, 21 U.S.C. 346a, 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-2009-0009 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 February 16, 2010.
    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-2009-0009, 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 Facility'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 Facility telephone number is (703) 305-5805.

II. Petition for Tolerance

    In the Federal Register of April 8, 2009 (74 FR 15971) (FRL-8407-
4), 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 (PPs 
8F7430 and 8F7439) by E.I. du Pont de Nemours and Company, Laurel Run 
Plaza, P.O. Box 80038, Wilmington, DE 19880-0038. The petitions 
requested that 40 CFR 180.429 be amended by establishing tolerances for 
residues of the herbicide chlorimuron ethyl, ethyl 2-[[[[(4-chloro-6-
methoxypyrimidin-2yl)amino]carbonyl]sulfonyl]benzoate], in or on (PP 
8F7430) corn, field grain at 0.01 parts per million (ppm); corn, field, 
forage at 0.5 ppm; corn, field, stover at 2.0 ppm; corn, field, meal at 
0.014 ppm; corn, field, flour at 0.015 ppm; corn, aspirated grain 
fractions at 1.28 ppm; and (PP 8F7439) soybean, seed at 0.01 ppm; 
soybean, forage at 0.45 ppm; soybean, hulls at 0.04 ppm; soybean, 
aspirated grain fractions at 2.79 ppm; and soybean, hay at 1.8 ppm. 
That notice referenced a summary of the petition prepared by E.I. du 
Pont de Nemours and Company, 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 
determined that tolerances are not needed for residues of chlorimuron 
ethyl on the following: Corn, field, meal; corn, field, flour; and 
soybean, hulls. EPA has also determined that the presently established 
tolerance of 0.05 ppm is appropriate for soybean in lieu of the 
proposed tolerance of 0.01 ppm for soybean, seed. Because soybean, seed 
is the designated EPA term for soybeans, the existing soybean tolerance 
is being amended to use that term. Additionally, EPA has determined 
that a single tolerance of 3.0 ppm should be established for grain, 
aspirated fractions in lieu of the proposed separate tolerances on 
corn, aspirated grain fractions; and soybean, aspirated grain 
fractions. EPA has also revised the tolerance expression for 
chlorimuron ethyl to clarify the chemical moieties that are covered by 
the tolerances and specify how compliance with the tolerances is to be 
measured. The reasons for these changes are explained in Unit IV.C.

III. Aggregate Risk Assessment and Determination of Safety

    Section 408(b)(2)(A)(i) of 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 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. . . 
.''
    Consistent with section 408(b)(2)(D) of FFDCA, and the factors 
specified in 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 for the petitioned-for 
tolerances for residues of chlorimuron ethyl, including its metabolites 
and degradates on corn, field forage at 0.5 ppm; corn, field, grain at 
0.01 ppm; corn, field, stover at 2.0 ppm; grain, aspirated fractions at 
3.0 ppm; soybean,

[[Page 67084]]

forage at 0.45 ppm; and soybean, hay at 1.8 ppm. EPA's assessment of 
exposures and risks associated with establishing tolerances 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.
    Chlorimuron ethyl has low or minimal acute toxicity via the oral, 
dermal and inhalation routes of exposure. It is mildly irritating to 
the eye and non-irritating to the skin; it is not a skin sensitizer.
    In subchronic toxicity studies with chlorimuron ethyl: No adverse 
effects were observed up to the limit dose tested in mice; decreased 
body weight gain and liver pathology (margination of hepatocyte 
cytoplasmic content in the centrilobular areas) were observed in rats 
(males only); and mild hemolytic anemia, atrophy of the thymus and 
prostate and increased liver weights were seen in dogs. Chronic 
exposure of dogs to chlorimuron ethyl also led to mild anemia 
(decreased erythrocyte count, hematocrit, and hemoglobin 
concentration), but atrophy of the thymus and prostate were not seen. 
In rats, treatment-related effects observed were limited to decreased 
body weight and body weight gain in both sexes after long-term 
exposure. Prostatitis (males) and fatty replacement in the pancreas 
(both sexes) were also observed but considered incidental occurrences. 
Biliary hyperplasia/fibrosis seen in females was attributed to aging. 
In mice, there were no treatment-related effects observed up to the 
highest dose tested (216 milligrams/kilograms/day (mg/kg/day)). There 
were no treatment-related increases in tumors in rat and mouse 
carcinogenicity studies after exposure to chlorimuron ethyl. 
Chlorimuron ethyl is classified as ``Not Likely to be Carcinogenic to 
Humans.''
    In the developmental toxicity studies, decreases in maternal body 
weight gain and delayed ossification in fetuses were observed in rats 
at the same dose (150 mg/kg/day). In rabbits, decreases in maternal 
body weight gain were seen at 300 mg/kg/day, while delayed ossification 
was seen in fetuses at a lower dose of 48 mg/kg/day, indicating 
increased quantitative susceptibility. In a guideline 2-generation 
reproduction study in rats, decreased body weight and histopathology in 
the cerebellum (cellular changes in the internal granular and external 
germinal layers) were seen in pups at 177 mg/kg/day. These effects were 
seen in the absence of maternal toxicity, indicating potential 
increased quantitative susceptibility of the pups to chlorimuron ethyl. 
However, these effects were not associated with any neurotoxicity or 
neurobehavioral changes and were not observed in other reproduction 
studies in rats. In a non-guideline reproduction toxicity study (1-
generation) in rats, decreased body weight (females) and liver 
histopathology (males) were seen in parental animals at 173 mg/kg/day, 
along with decreases in litter weights. In another reproduction study 
(1-year interim sacrifice) in rats, decreases in maternal and pup body 
weights were observed at 195 mg/kg/day.
    There is no indication of neurotoxicity in the toxicity database 
for chlorimuron ethyl. In a 2-generation reproduction study in rats, 
histopathological alterations were seen in the cerebellum (cellular 
changes in the internal granular and external germinal layers) of F2 
pups at 177 mg/kg/day; however, these findings were not associated with 
any neurobehavioral changes or any indications of neurotoxicity. In 
addition, these histopathological alterations were not observed in two 
other reproduction studies, and there was no evidence of neurotoxicity 
observed in other rat toxicity studies or toxicity studies in other 
species (rabbits, mice, or dogs).
    Hematological changes (indicative of mild anemia) and atrophy of 
the thymus were observed in dogs after subchronic exposure. However, 
atrophy of the thymus was not associated with any histopathology and 
not seen after chronic exposure. No other potential immunotoxic effects 
were observed in the toxicology database.
    Specific information on the studies received and the nature of the 
adverse effects caused by chlorimuron ethyl 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 in document ``Chlorimuron ethyl. Human Health Risk 
Assessment for Proposed Uses on Field Corn and Soybean, PPs 8F7430 and 
8F7439,'' page 45 in docket ID number EPA-HQ-OPP-2009-0009.

B. Toxicological Endpoints

    For hazards that have a threshold below which there is no 
appreciable risk, a toxicological point of departure (POD) is 
identified as the basis for derivation of reference values for risk 
assessment. The POD may be defined as the highest dose at which no 
adverse effects are observed (the NOAEL) in the toxicology study 
identified as appropriate for use in risk assessment. However, if a 
NOAEL cannot be determined, the lowest dose at which adverse effects of 
concern are identified (the LOAEL) or a Benchmark Dose (BMD) approach 
is sometimes used for risk assessment. Uncertainty/safety factors (UFs) 
are used in conjunction with the POD 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 
dietary risks by comparing aggregate food and water 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 POD by all applicable UFs. Aggregate short-, intermediate-
, and chronic-term risks are evaluated by comparing food, water, and 
residential exposure to the POD to ensure that the margin of exposure 
(MOE) called for by the product of all applicable UFs is not exceeded. 
This latter value is referred to as the Level of Concern (LOC).
    For non-threshold risks, the Agency assumes that any amount of 
exposure will lead to some degree of risk. Thus, the Agency estimates 
risk in terms of the probability of an occurrence of the adverse effect 
greater than that expected in a lifetime. 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/
pesticides/factsheets/riskassess.htm.
    A summary of the toxicological endpoints for chlorimuron ethyl used 
for human risk assessment can be found at http://www.regulations.gov in 
document ``Chlorimuron ethyl. Human Health Risk Assessment for Proposed 
Uses on Field Corn and Soybean, PPs 8F7430 and 8F7439,'' page 20 in 
docket ID number EPA-HQ-OPP-2009-0009.

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. In evaluating dietary 
exposure to chlorimuron ethyl, EPA considered exposure under the 
petitioned-for tolerances as well as all existing chlorimuron ethyl 
tolerances in 40 CFR 180.429. EPA assessed dietary exposures from 
chlorimuron ethyl 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

[[Page 67085]]

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 chlorimuron ethyl; therefore, a quantitative acute dietary 
exposure assessment is unnecessary.
    ii. Chronic exposure. In conducting the chronic dietary exposure 
assessment EPA used the food consumption data from the USDA 1994-1996 
and 1998 Continuing Surveys of Food Intakes by Individuals (CSFII). As 
to residue levels in food, EPA assumed tolerance-level residues and 100 
percent crop treated (PCT) for all existing and new uses of chlorimuron 
ethyl.
    iii. Cancer. Based on the results of carcinogenicity studies in 
rats and mice, EPA classified chlorimuron ethyl as ``Not Likely to be 
Carcinogenic to Humans.'' Therefore, an exposure assessment for 
evaluating cancer risk is not needed for this chemical.
    2. Dietary exposure from drinking water. The Agency used screening 
level water exposure models in the dietary exposure analysis and risk 
assessment for chlorimuron ethyl in drinking water. These simulation 
models take into account data on the physical, chemical, and fate/
transport characteristics of chlorimuron ethyl. 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 Reservoir Screening Tool (FIRST) and 
Screening Concentration in Ground Water (SCI-GROW) models, the 
estimated drinking water concentrations (EDWCs) of chlorimuron ethyl 
were determined for acute exposures and chronic exposures for non-
cancer assessments assuming a maximum seasonal use rate of 0.25 lb 
chlorimuron ethyl per acre. EDWCs for acute exposures are estimated to 
be 11.98 parts per billion (ppb) for surface water and 6.99 ppb for 
ground water. EDWCs for chronic exposures for non-cancer assessments 
are estimated to be 5.02 ppb for surface water and 6.99 ppb for ground 
water.
    Modeled estimates of drinking water concentrations were directly 
entered into the dietary exposure model. For chronic dietary risk 
assessment, the most conservative water concentration value of 6.99 ppb 
was used to assess the contribution to chlorimuron ethyl dietary 
exposure from drinking water. Acute dietary risk assessments were not 
conducted since no toxicological endpoint attributable to a single dose 
of chlorimuron ethyl has been identified. Cancer dietary risk 
assessments were not conducted since there is no cancer concern for 
chlorimuron ethyl.
    In a summary of results from a pilot monitoring program conducted 
by the U.S. Geological Survey, data show that chlorimuron ethyl has 
been detected in drinking water of water supply reservoirs, but only at 
maximum concentrations magnitudes lower than those predicted by the 
FIRST model.
    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). Chlorimuron ethyl is 
not registered for any specific use patterns that would result in 
residential exposure.
    4. Cumulative effects from substances with a common mechanism of 
toxicity. Section 408(b)(2)(D)(v) of 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.''
    EPA has not found chlorimuron ethyl to share a common mechanism of 
toxicity with any other substances, and chlorimuron ethyl does not 
appear to produce a toxic metabolite produced by other substances. For 
the purposes of this tolerance action, therefore, EPA has assumed that 
chlorimuron ethyl does not have 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 EPA's website at http://
www.epa.gov/pesticides/cumulative.

D. Safety Factor for Infants and Children

    1. In general. Section 408(b)(2)(C) of FFDCA provides that EPA 
shall apply an additional tenfold (10X) 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 database 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 SF. In 
applying this provision, EPA either retains the default value of 10X, 
or uses a different additional safety factor when reliable data 
available to EPA support the choice of a different factor.
    2. Prenatal and postnatal sensitivity. The prenatal and postnatal 
toxicity database for chlorimuron ethyl includes guideline rat and 
rabbit developmental toxicity studies and a 2-generation reproduction 
toxicity study in rats, as well as two additional non-guideline 
reproduction studies in rats (a 1-generation study and 1-year interim 
sacrifice study). No evidence of increased prenatal or postnatal 
susceptibility was seen in the developmental toxicity study in rats or 
in the non-guideline reproduction toxicity studies in rats. In the 
rabbit developmental study, delayed ossification was observed in 
fetuses at 48 mg/kg/day, while maternal effects (decreased body weight 
gain) were seen at 300 mg/kg/day, suggesting increased quantitative 
susceptibility of fetuses. In the 2-generation rat reproduction study, 
decreased body weight and histopathology findings in the cerebellum 
were observed in pups at 177/214 mg/kg/day (male/female) in the absence 
of maternal toxicity, also suggesting increased quantitative 
susceptibility of the pups.
    Although the data suggest increased quantitative susceptibility in 
the developmental rabbit study and the 2-generation rat reproduction 
study, there are no residual uncertainties with regard to prenatal 
toxicity following in utero exposure of rats or rabbits or prenatal 
and/or postnatal exposures of rats. The fetal effect seen in rabbits 
was limited to delayed ossification, and, although effects 
(histopathology in the cerebellum) were seen in a rat reproduction 
study, there was no evidence of increased susceptibility observed in 
two additional reproduction studies in rats. Additionally, there are 
clear NOAELs for the offspring effects seen in rabbits (NOAEL=13 mg/kg/
day) and rats (17 mg/kg/day). Finally, the NOAEL (9 mg/kg/day) used to 
establish the chronic Reference Dose of 0.09 mg/kg/day is considered 
protective of potential developmental effects observed at the higher 
doses. Considering the overall toxicity database and doses selected for 
risk assessment, the degree of concern for the effects observed in the 
studies is low.
    3. Conclusion. EPA has determined that reliable data show the 
safety of infants and children would be adequately protected if the 
FQPA SF were reduced to 1X. That decision is based on the following 
findings:
    The toxicity database for chlorimuron ethyl is adequate to 
characterize potential prenatal and postnatal risk for infants and 
children. Acceptable/guideline studies for developmental toxicity in 
rats and rabbits and reproduction toxicity in rats are available for 
FQPA assessment.

[[Page 67086]]

    On December 26, 2007, EPA began requiring functional immunotoxicity 
testing and acute and subchronic neurotoxicity testing of all food and 
non-food use pesticides. These studies are not yet available for 
chlorimuron ethyl. In the absence of specific immunotoxicity and 
neurotoxicity studies, EPA has evaluated the available chlorimuron 
ethyl toxicity data and determined that an additional uncertainty 
factor is not required to account for the lack of these studies. The 
reasons for this determination are explained below:
    i. Hematological changes (indicative of mild anemia) and atrophy of 
the thymus were observed in dogs following subchronic exposure to 
chlorimuron-ethyl at a dose of 45.8/42.7 (M/F) mg/kg/day, indicating 
potential immunotoxicity. However, atrophy of the thymus was not 
associated with any histopathology and was not seen after chronic 
exposure; and no other potential immunotoxic effects were observed in 
the toxicology database. Therefore, EPA does not believe that 
conducting immunotoxicity testing will result in a NOAEL less than the 
NOAEL of 9 mg/kg/day already established for chlorimuron ethyl, and an 
additional factor (UFDB) for database uncertainties is not needed to 
account for potential immunotoxicity.
    ii. There is no indication in the toxicity database that 
chlorimuron ethyl is a neurotoxic chemical. No signs indicative of 
neurotoxicity were seen in subchronic and chronic studies conducted 
with dogs, mice and rats. In a 2-generation reproduction study in rats, 
histopathological alterations were seen in the cerebellum of F2 pups at 
the high dose (177 mg/kg/day). However, these findings were not 
associated with any neurobehavioral changes or any other indications of 
neurotoxicity. In addition, these histopathological alterations were 
not observed in two other reproduction studies with chlorimuron ethyl. 
Based on these considerations, EPA does not believe that a 
developmental neurotoxicity study is warranted at this time and there 
is no need for an additional UF to account for the lack of acute and 
subchronic neurotoxicity studies.
    iii. Although there is evidence of increased quantitative 
susceptibility in the developmental rabbit study and the 2-generation 
rat reproduction study, the degree of concern for the effects observed 
in the studies is low, and there are no residual uncertainties with 
regard to prenatal toxicity following in utero exposure of rats or 
rabbits or prenatal and/or postnatal exposures of rats.
    iv. There are no residual uncertainties identified in the exposure 
databases. The food exposure assessments were performed based on the 
assumptions of 100 PCT and tolerance-level residues. EPA made 
conservative (protective) assumptions in the ground and surface water 
modeling used to assess exposure to chlorimuron ethyl in drinking 
water. Chlorimuron ethyl is not registered for residential use. These 
assessments will not underestimate the exposure and risks posed by 
chlorimuron ethyl.

E. Aggregate Risks and Determination of Safety

    EPA determines whether acute and chronic pesticide exposures are 
safe by comparing aggregate exposure estimates to the aPAD and cPAD. 
The aPAD and cPAD represent the highest safe exposures, taking into 
account all appropriate SFs. EPA calculates the aPAD and cPAD by 
dividing the POD by all applicable UFs. For linear cancer risks, EPA 
calculates the probability of additional cancer cases given the 
estimated aggregate exposure. Short-, intermediate-, and chronic-term 
risks are evaluated by comparing the estimated aggregate food, water, 
and residential exposure to the POD to ensure that the MOE called for 
by the product of all applicable UFs is not exceeded.
    1. Acute risk. An acute aggregate risk assessment takes into 
account exposure estimates from acute dietary consumption of food and 
drinking water. No adverse effect resulting from a single-oral exposure 
was identified and no acute dietary endpoint was selected. Therefore, 
chlorimuron ethyl 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 chronic exposure to 
chlorimuron ethyl from food and water will utilize 1% or less of the 
cPAD for the general population and all population subgroups, including 
infants and small children. There are no residential uses for 
chlorimuron ethyl.
    3. Short/intermediate-term risk. Short-term and intermediate-term 
aggregate exposure take into account short-term or intermediate-term 
residential exposure plus chronic exposure from food and water 
(considered to be a background exposure level). Chlorimuron ethyl is 
not registered for any use patterns that would result in residential 
exposure. Therefore, the short-term or intermediate-term aggregate risk 
is the sum of the risk from exposure to chlorimuron ethyl through food 
and water and will not be greater than the chronic aggregate risk.
    4. Aggregate cancer risk for U.S. population. Based on a lack of 
evidence for carcinogenicity in mice and rats following long-term 
dietary administration, chlorimuron ethyl is not expected to pose a 
cancer risk.
    5. 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 chlorimuron ethyl residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    Adequate enforcement methodology (high performance liquid 
chromatography (HPLC) using a photoconductivity detector with a method 
limit of quantitation (LOQ) of 0.01 ppm (AMR-459-85)) 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 no established or proposed Codex or Mexican maximum 
residue limits (MRLs) for residues of chlorimuron ethyl for corn or 
soybean commodities; however, there is a Canadian MRL for soybeans 
(0.05 mg/kg), which harmonizes with the current U.S. tolerance on 
soybeans.

C. Revisions to Petitioned-For Tolerances

    EPA has determined that tolerances are not needed for the 
following: Corn, field, meal; corn, field, flour; and soybean, hulls. 
Tolerances for the processed commodities of corn, field, meal and corn, 
field, flour are not needed because these commodities are not expected 
to have residues greater than the tolerance on the raw agricultural 
commodity, field corn grain. EPA has also determined that tolerances 
for corn and soybean aspirated grain fractions will not be listed 
individually, but will be combined under the single tolerance, grain, 
aspirated fractions at 3.0 ppm based on the soybean aspirated grain 
fraction data. The current tolerance for residues of chlorimuron ethyl 
on soybeans at 0.05 ppm is not being amended as requested. Although 
adequate residue data are available indicating that residues on soybean 
were less than 0.01 ppm in/on all seed samples following an application 
at the R1-R2 stage, the existing 0.05 ppm

[[Page 67087]]

tolerance will cover this use and is additionally required for 
harmonization purposes with the Canadian MRL. However, the soybean 
tolerance is being amended to change the commodity name to ``soybean, 
seed'' which is the current EPA designated term for this commodity. A 
tolerance for residues in/on soybean, hulls is not required as this 
commodity will be covered by the existing 0.05 ppm tolerance on 
soybean, seed.
    Finally, EPA is revising the tolerance expression for all new and 
existing commodities to clarify the chemical moieties that are covered 
by the tolerances and specify how compliance with the tolerances is to 
be measured. The revised tolerance expression makes clear that the 
tolerances cover ``residues of chlorimuron ethyl, including its 
metabolites and degradates'' and that compliance with the tolerance 
levels will be determined by measuring only chlorimuron ethyl, ethyl 2-
[[[[(4-chloro-6-methoxypyrimidin-2yl)amino]carbonyl]sulfonyl]benzoate]. 
EPA has determined that it is reasonable to make this change final 
without prior proposal and opportunity for comment, because public 
comment is not necessary, in that the change has no substantive effect 
on the tolerance, but rather is merely intended to clarify the existing 
tolerance expression.

V. Conclusion

    Therefore, tolerances are established for residues of chlorimuron 
ethyl, including its metabolites and degradates, in or on corn, field 
grain at 0.01 ppm; corn, field, forage at 0.5 ppm; corn, field, stover 
at 2.0 ppm; soybean, forage at 0.45 ppm; soybean, hay at 1.8 ppm, and 
grain, aspirated fractions at 3.0 ppm. In addition, the presently 
established tolerance term, ``Soybean'' is being revised to ``Soybean, 
seed.'' Compliance with the tolerance levels will be determined by 
measuring only chlorimuron ethyl, ethyl 2-[[[[(4-chloro-6-
methoxypyrimidin-2yl)amino]carbonyl]sulfonyl]benzoate], in or on the 
commodity.

VI. Statutory and Executive Order Reviews

    This final rule establishes tolerances 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 final rule has been 
exempted from review under Executive Order 12866, this final rule is 
not subject to Executive Order 13211, entitled 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 9, 2000) do not apply to this final rule. In addition, 
this final 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: December 8, 2009.
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 180.429 is amended by revising the introductory text to 
paragraph (a), revising the tolerance term ``Soybean'' to read 
``Soybean, seed'' and alphabetically adding the following commodities 
to the table in paragraph (a) to read as follows:

Sec.  180.429  Chlorimuron ethyl; tolerances for residues.

    (a) General. Tolerances are established for residues of the 
herbicide chlorimuron ethyl, including its metabolites and degradates, 
in or on the commodities in the table below. Compliance with the 
tolerance levels specified in the following table is to be determined 
by measuring only chlorimuron ethyl, ethyl 2-[[[[(4-chloro-6-
methoxypyrimidin-2yl)amino]carbonyl]sulfonyl]benzoate] in or on the 
following commodities:

------------------------------------------------------------------------
                      Commodity                        Parts per million
------------------------------------------------------------------------
                                * * * * *
Corn, field, forage..................................                0.5
Corn, field, grain...................................               0.01
Corn, field, stover..................................                2.0
Grain, aspirated fractions...........................                3.0
                                * * * * *
Soybean, forage......................................               0.45
Soybean, hay.........................................                1.8
Soybean, seed........................................               0.05
------------------------------------------------------------------------

[[Page 67088]]

* * * * *

[FR Doc. E9-30032 Filed 12-17-09; 8:45 am]

BILLING CODE 6560-50-S