[Federal Register Volume 67, Number 107 (Tuesday, June 4, 2002)]
[Rules and Regulations]
[Pages 38407-38418]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-13982]


-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-2002-0087; FRL-7178-5]


Cyhalofop-butyl; Time-Limited Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This regulation establishes a time-limited tolerance for 
combined residues of cyhalofop (cyhalofop-butyl plus cyhalofop-acid) 
and the di-acid metabolite in or on rice grain and rice straw. Dow 
AgroSciences, LLC requested this tolerance under the Federal Food, 
Drug, and Cosmetic Act, as amended by the Food Quality Protection Act 
of 1996. The tolerance will expire on June 1, 2007.

DATES: This regulation is effective June 4, 2002. Objections and 
requests for hearings, identified by docket ID number OPP-2002-0087, 
must be received on or before August 5, 2002.

ADDRESSES: Written objections and hearing requests may be submitted by 
mail, in person, or by courier. Please follow the detailed instructions 
for each method as provided in Unit VI. of the SUPPLEMENTARY 
INFORMATION. To ensure proper receipt by EPA, your objections and 
hearing requests must identify docket ID number OPP-2002-0087 in the 
subject line on the first page of your response.

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

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

    You may be affected by this action if you are an agricultural 
producer, food manufacturer, or pesticide manufacturer. Potentially 
affected categories and entities may include, but are not limited to:

------------------------------------------------------------------------
                                                          Examples of
           Categories                 NAICS codes         potentially
                                                       affected entities
------------------------------------------------------------------------
Industry                          111                  Crop production
                                  112...............  Animal production
                                  311...............  Food manufacturing
                                  32532.............   Pesticide
                                                       manufacturing
------------------------------------------------------------------------

    This listing is not intended to be exhaustive, but rather provides 
a guide for readers regarding entities likely to be affected by this 
action. Other types of entities not listed in the table could also be 
affected. The North American Industrial Classification System (NAICS) 
codes have been provided to assist you and others in determining 
whether or not this action might apply to certain entities. If you have 
questions regarding the applicability of this action to a particular 
entity, consult the person listed under FOR FURTHER INFORMATION 
CONTACT.

B. How Can I Get Additional Information, Including Copies of this 
Document and Other Related Documents?

    1. Electronically.You may obtain electronic copies of this 
document, and certain other related documents that might be available 
electronically, from the EPA Internet Home Page at http://www.epa.gov/. 
To access this document, on the Home Page select ``Laws and 
Regulations,'' ``Regulations and Proposed Rules,''and then look up the 
entry for this document under the ``Federal Register--Environmental 
Documents.'' You can also go directly to the Federal Register listings 
at http://www.epa.gov/fedrgstr/. A frequently updated electronic 
version of 40 CFR part 180 is available at http://www.access.gpo.gov/nara/cfr/cfrhtml_00/Title_40/40cfr180_00.html, a beta site currently 
under development. To access the OPPTS Harmonized Guidelines referenced 
in this document, go directly to the guidelines at http://www.epa.gov/opptsfrs/home/guidelin.htm.
    2. In person. The Agency has established an official record for 
this action under docket ID number OPP-2002-0087. The official record 
consists of the documents specifically referenced in this action, and 
other information related to this action, including any information 
claimed as Confidential Business Information (CBI). This official 
record includes the documents that are physically located in the 
docket, as well as the documents that are referenced in those 
documents. The public version of the official record does not include 
any information claimed as CBI. The public version of the official 
record, which includes printed, paper versions of any electronic 
comments submitted during an applicable comment period is available for 
inspection in the Public Information and Records Integrity Branch 
(PIRIB), Rm. 119, Crystal Mall 2, 1921 Jefferson Davis Hwy., 
Arlington, VA, from 8:30 a.m. to 4 p.m., Monday through Friday, 
excluding legal holidays. The PIRIB telephone number is (703) 305-5805.

II. Background and Statutory Findings

    In the Federal Register of April 25, 2001 (66 FR 20808) (FRL-6774-
7), EPA issued a notice pursuant to section 408 of the Federal Food, 
Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a, as amended by the Food 
Quality Protection Act of 1996 (FQPA) (Public Law 104-

[[Page 38408]]

170), announcing the filing of a pesticide petition (PP 0F6089) by Dow 
AgroSciences, LLC, 9330 Zionsville Road, Indianapolis, IN 46268. This 
notice included a summary of the petition prepared by Dow AgroSciences, 
LLC, theregistrant. There were no comments received in response to the 
notice of filing.
    The petition requested that 40 CFR part 180 be amended by 
establishing tolerances for combined residues of the herbicide 
cyhalofop-butyl (cyhalofop-butyl, cyhalofop-acid and cyhalofop-diacid) 
in or on rice grain, rice hull, rice bran and polished rice at 0.03 
parts per million (ppm) and rice straw at 8.0 ppm.
    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) 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) 
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 and a complete description of 
the risk assessment process, see the final rule on Bifenthrin Pesticide 
Tolerances (62 FR 62961, November 26, 1997) (FRL-5754-7).

III. Aggregate Risk Assessment and Determination of Safety

    Consistent with 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, consistent with section 
408(b)(2), for a tolerance for combined residues of cyhalofop 
(cyhalofop-butyl plus cyhalofop acid) and the di-acid metabolite in or 
on rice grain at 0.03 ppm and rice straw at 8.0 ppm. Tolerances are not 
required for rice processed fractions or for animal commodities. 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. The nature of the toxic effects caused by cyhalofop-butyl are 
discussed in the following Table 1 and Table 2 as well as the no 
observed adverse effect level (NOAEL) and the lowest observed adverse 
effect level (LOAEL) from the toxicity studies reviewed.

          Table 1.--Acute Toxicity of Cyhalofop-butyl Technical
------------------------------------------------------------------------
          Guideline No.               Study Type            Results
------------------------------------------------------------------------
870.1100                          Acute Oral (Rat)    LD50 >5000 mg/kg
                                                       (limit test)
                                                      There was no
                                                       evidence of
                                                       toxicity.
                                                      Toxicity Category
                                                       IV
------------------------------------------------------------------------
870.1100                          Acute Oral (Mice)   LD50 >5000 mg/kg
                                                       (limit test)
                                                      There was no
                                                       evidence of
                                                       toxicity.
                                                      Toxicity Category
                                                       IV
------------------------------------------------------------------------
870.1200                          Acute Dermal (Rat)  LD50 >5000 mg/kg
                                                       (2.5 x the limit
                                                       dose)
                                                      Chromodacryorrhea
                                                       was observed in 2/
                                                       5 males on day 2
                                                       only. Delayed
                                                       weight gain was
                                                       observed in all
                                                       rats, with the
                                                       females being
                                                       most affected.
                                                       There was no
                                                       dermal
                                                       irritation.
                                                      Toxicity Category
                                                       IV
------------------------------------------------------------------------
870.1300                          Acute Inhalation    LC50 >5.63 mg/L
                                   (Rat)               (2.8 x the limit
                                                       concentration)
                                                      Bradypnea was
                                                       noted in all rats
                                                       with recovery
                                                       within two hours
                                                       following
                                                       exposure.
                                                       Abnormal
                                                       respiratory
                                                       sounds were noted
                                                       in all rats after
                                                       exposure with
                                                       recovery by day
                                                       1. Reddish
                                                       adhesive
                                                       materials in the
                                                       nasorostral and
                                                       periocular
                                                       regions were
                                                       noted from all
                                                       test rats after
                                                       exposure with
                                                       recovery by day
                                                       2. No gross
                                                       abnormalities.
                                                      Two control rats
                                                       had reddish
                                                       adhesive
                                                       materials in the
                                                       nasorostral
                                                       region after
                                                       exposure with
                                                       recovery within
                                                       two hours.
                                                      Toxicity Category
                                                       IV
------------------------------------------------------------------------
870.2400                          Primary Eye         Minimally
                                   Irritation -        irritating
                                   Rabbit             Toxicity Category
                                                       IV
------------------------------------------------------------------------
870.2500                          Primary Skin        Essentially
                                   Irritation -        nonirritating
                                   Rabbit             Toxicity Category
                                                       IV
------------------------------------------------------------------------
870.2600                          Dermal              Not a dermal
                                   Sensitization -     sensitizer
                                   Guinea Pig
------------------------------------------------------------------------


[[Page 38409]]


                                Table 2.--Subchronic, Chronic, and Other Toxicity
----------------------------------------------------------------------------------------------------------------
             Guideline No.                       Study Type                            Results
----------------------------------------------------------------------------------------------------------------
870.3100                                 Subchronic (4 and 13 Week)  NOAEL (male)[]400 mg/kg/
                                          Feeding (Rat)               day (Highest Dose Tested [HDT] in male)
                                                                     NOAEL (female) = 400 mg/kg/day
                                                                     LOAEL (female) = 800 mg/kg/day
                                                                     (HDT in female) based on perineal soiling
                                                                      and reduced body weights and body weight
                                                                      gain.
----------------------------------------------------------------------------------------------------------------
870.3100                                 Subchronic Feeding (Rat)    NOAEL = 60.5/65.3 mg/kg/day,M/F
                                                                     LOAEL = 189.5/199.6 mg/kg/day, M/F (HDT)
                                                                      based on kidney toxicity (lipofuscin
                                                                      pigment deposition in proximal tubule
                                                                      cells) in both sexes, and possible liver
                                                                      toxicity (hepatocyte eosinophilic
                                                                      granules) in males.
----------------------------------------------------------------------------------------------------------------
870.3100                                 Subchronic Feeding (Mice)   NOAEL (male)[]30 mg/kg/
                                                                      day (HDT in male)
                                                                     NOAEL (female)[]100 mg/kg/
                                                                      day (HDT in female)
----------------------------------------------------------------------------------------------------------------
870.3100                                 Subchronic Feeding (Mice)   NOAEL (male) []37.5 mg/kg/
                                                                      day (HDT)
                                                                     NOAEL (female) = 4.3 mg/kg/day
                                                                     LOAEL (female) = 14.1 mg/kg/daybased on
                                                                      enlarged kidneys (20% absolute and
                                                                      relative) accompanied by swelling of the
                                                                      proximal tubule cells (4/12 mice).
----------------------------------------------------------------------------------------------------------------
870.3150                                 Subchronic Feeding (Dog)    NOAEL = 14.7 / 15.6 mg/kg/day, M/F
                                                                     LOAEL = 75.2 / 79.4 mg/kg/day, M/F (HDT)
                                                                      based on brown and/or atrophied thymuses,
                                                                      and decreased thymus weight.
----------------------------------------------------------------------------------------------------------------
870.3200                                 21-Day Dermal (Rat)         Systemic NOAEL []1000 mg/
                                                                      kg/day (limit dose)
                                                                     Dermal NOAEL []1000 mg/kg/
                                                                      day (limit dose)
----------------------------------------------------------------------------------------------------------------
870.3700                                 Gavage Developmental        Maternal NOAEL =1000 mg/kg/day (limit dose)
                                          Toxicity (Rat)             Developmental NOAEL []1000 mg/kg/day (limit dose)
----------------------------------------------------------------------------------------------------------------
870.3700                                 Gavage Developmental        Maternal NOAEL = 40 mg/kg/day
                                          Toxicity (Rabbit)          Maternal LOAEL = 200 mg/kg/day based on
                                                                      maternal death
                                                                     Developmental NOAEL []1000 mg/kg/day (limit dose)
----------------------------------------------------------------------------------------------------------------
870.3800                                 Feeding Reproductive        Systemic NOAEL (males) = 100 ppm (4.85-
                                          Toxicity (Rat)              13.75 mg/kg/day)
                                                                     Systemic LOAEL (males) = 1000 ppm (50.0-
                                                                      138.7 mg/kg/day) based on kidney lesions
                                                                      (slight tubular cell swelling) in F0 and
                                                                      F1 male rats.
                                                                     Systemic NOAEL (females) []1000 ppm (69.2-147.7 mg/kg/day, HDT)
                                                                     Reproductive NOAEL []1000
                                                                      ppm (50.1-138.7 mg/kg/day for males; 69.2-
                                                                      147.7 mg/kg/day for females)
                                                                     Offspring NOAEL []1000
                                                                      ppm (50-147.7 mg/kg/day)
----------------------------------------------------------------------------------------------------------------
870.4100                                 Chronic Feeding Toxicity    NOAEL []46.7 / 45.9 mg/kg/
                                          (Dog)                       day; M/F (HDT)
----------------------------------------------------------------------------------------------------------------
870.4200                                 Carcinogenicity Feeding     NOAEL = 0.99 mg/kg/day
                                          (Mouse)                    LOAEL = 10.06 / 10.28 mg/kg/day, M/F (HDT)
                                                                      based on effects on the kidney including
                                                                      tubular dilatation, chronic
                                                                      glomerulonephritis, and hyaline casts in
                                                                      females, and hyperplasia of the stomach
                                                                      mucosal epithelium in males. There was no
                                                                      evidence of carcinogenic potential under
                                                                      the conditions of this study. Dosing was
                                                                      too low to elicit frank toxicity and
                                                                      inadequate to assess carcinogenic
                                                                      potential.
----------------------------------------------------------------------------------------------------------------
870.4300                                 Chronic Feeding Toxicity /  NOAEL = 0.823 mg/kg/day in males and 2.475
                                          Carcinogenicity (Rat)       mg/kg/day in females
                                                                     LOAEL = 3.44 mg/kg/day (HDT in males),
                                                                      24.97 mg/kg/day (HDT in females) based on
                                                                      the early and increased deposition of the
                                                                      pigments lipofuscin and hemosiderin in the
                                                                      renal proximal tubular cells of both
                                                                      sexes, and renal mineralization in female
                                                                      rats. There were no treatment-related
                                                                      increases in tumor incidence, compared to
                                                                      controls. Dosing was too low to elicit
                                                                      frank toxicity and inadequate to assess
                                                                      carcinogenic potential.
----------------------------------------------------------------------------------------------------------------
870.5100                                 Bacterial Reverse Gene      Negative in Salmonella TA strains and E.
                                          Mutation Test (Ames         coli WP2 uvrA.
                                          Assay)
----------------------------------------------------------------------------------------------------------------
870.5300                                 Gene Mutation in Mouse      Negative
----------------------------------------------------------------------------------------------------------------
870.5375                                 In Vitro Cheomosomal        Polyploidy was induced when CHL (V79) cells
                                          Aberration in Chinese       were treated for 48 hours in the absence
                                          Hamster Lung                of S9, but there was no clastogenic effect
                                                                      on DNA.
----------------------------------------------------------------------------------------------------------------

[[Page 38410]]

 
870.5395                                 In Vivo Mammalian           Negative
                                          Cytogenetics -
                                          Micronucleus Assay in
                                          Mouse Bone Marrow Cells
----------------------------------------------------------------------------------------------------------------
870.5550                                 Unscheduled DNA Synthesis   Negative
                                          in Rat Hepatocytes
----------------------------------------------------------------------------------------------------------------
870.6200                                 Gavage Acute Neurotoxicity  NOAEL []2000 mg/kg (limit
                                          (Rat)                       dose) based on the absence of clinical
                                                                      signs, a lack of effects on FOB parameters
                                                                      and motor activity, and the absence of
                                                                      neuropathologic lesions.
----------------------------------------------------------------------------------------------------------------
870.6200                                 Feeding Subchronic          NOAEL []75 male/ []250 female mg/kg/day (HDT)
                                                                      based on the absence of clinical signs,
                                                                      lack of effects on FOB parameters and
                                                                      motor activity, and absence of
                                                                      neuropathologic lesions.
----------------------------------------------------------------------------------------------------------------
Special Study                            Pharmacology - Mice and     Mice: A single I.P. dose of 1250 or 5000 mg/
                                          Rabbits                     kg was lethal to all male and female mice
                                                                      within 24 hours. Death occurred as early
                                                                      as three hours at 5000 mg/kg and was
                                                                      preceded by behavioral and motor function
                                                                      abnormalities (e.g., alterations in
                                                                      alertness, visual placing, spontaneous
                                                                      activity, incoordination, decreased muscle
                                                                      tone, and compromised autonomic reflexes),
                                                                      some of which appeared as early as 30
                                                                      minutes postdosing. Male and female mice
                                                                      responded similarly.
                                                                     NOAEL = 78.1 mg/kg
                                                                     LOAEL = 313 mg/kg (based on minimal effects
                                                                      including decreased spontaneous activity,
                                                                      minor alterations in muscle tone, and
                                                                      minor changes in autonomic functions such
                                                                      as slight hyperthermia, and slightly
                                                                      decreasedrespiratory rate).
                                                                     LD[]1250 mg/kg
                                                                     Rabbits: One of three rabbits gavaged at
                                                                      5000 mg/kg showed decreased spontaneous
                                                                      activity, prostration, decreased muscle
                                                                      tone, compromised autonomic reflexes, and
                                                                      decreased respiratory and heart rate at
                                                                      one day after dosing, and died on Day 4.
                                                                      There were no clinically significant
                                                                      findings in the remaining rabbits of the
                                                                      5000 mg/kg dose group or any lower dose
                                                                      groups, and no significant effects on EKGs
                                                                      or blood pressure in any dosed rabbits.
                                                                     NOAEL = 2500 mg/kg
                                                                     LOAEL = 5000 mg/kg (based on the response
                                                                      of one of three test subjects including
                                                                      decreased spontaneous activity,
                                                                      prostration, decreased muscle tone,
                                                                      compromised autonomic reflexes, decreased
                                                                      respiratory and heart rate at one day
                                                                      after dosing, and death on day 4).
----------------------------------------------------------------------------------------------------------------
870.7485                                 Absorption, Metabolism,     No treatment-related adverse effects were
                                          and Excretion (Dog)         reported. Approximately 50% of a single
                                                                      gavage dose was absorbed over several
                                                                      hours. Bloodand plasma radioactivity
                                                                      peaked after 1-2 hours.
                                                                     Clearance from plasma and blood was
                                                                      notespecially rapid but nearly complete at
                                                                      48 hours. Over 168 hours, excretion was
                                                                      42.5-43.9% in the urine, and 48.6-50.6% in
                                                                      the feces. Tissue distribution was not
                                                                      measured. The test article appears to be
                                                                      metabolized primarily by hydrolysis to R-
                                                                      (+)-2-[4-cyano-2-
                                                                      fluorophenoxy)phenoxy]propanoic acid which
                                                                      was found in both the urine and feces.
                                                                      Several other metabolites were also
                                                                      formed, each representing <5% of the
                                                                      administered dose. No parent compound was
                                                                      found in the urine, and only minimal
                                                                      amounts were detected in the feces.
----------------------------------------------------------------------------------------------------------------
870.7485                                 Metabolism and              Absorption of gavaged test article was 93-
                                          Pharmacokinetics (Rat)      100%, and urinary excretion was the major
                                                                      route of elimination regardless of dose,
                                                                      label position, or gender. Over 168-hours,
                                                                      84-100% of the radioactivity was
                                                                      eliminated in urine, with 86-90%
                                                                      eliminated within 24 hours. Fecal
                                                                      excretion was <5%. There was no
                                                                      elimination via expired air. Over a 24-
                                                                      hour period, biliary elimination accounted
                                                                      for 1.7 % and 20.1% of the administered
                                                                      dose in males and females, respectively,
                                                                      in the low-dose [[alpha]-14C]XRD-537 BE
                                                                      group, and 17.0% (males) and 11.6%
                                                                      (females) of the administered dose in the
                                                                      [[beta]14C]XRD-537 BE low-dose group.
                                                                     The greatest radioactivity levels were
                                                                      found in liver, kidneys, plasma, whole
                                                                      blood, heart, lung, and stomach, with the
                                                                      highest tissue levels being found in the
                                                                      liver and kidney at 2 hours. Most tissue
                                                                      levels accounted for <1% of the
                                                                      administered dose. Due to rapid
                                                                      excretion,tissue/organ levels declined to
                                                                      near detection limits by 24 hours in all
                                                                      dose groups.

[[Page 38411]]

 
                                                                     There was a biphasic pattern for both
                                                                      labels with no substantial differences in
                                                                      pharmacokinetic indices (Cmax, tcmax, t1/
                                                                      2, AUC). Time-to-maximum plasma
                                                                      concentration (tcmax of 0.5 to 4 hrs)
                                                                      elimination half-times (t1/2) reflected
                                                                      the relatively rapid absorption. Females
                                                                      had somewhat shorter tcmax and lower Cmax
                                                                      values suggestive ofsaturated absorption
                                                                      processes. The acid metabolite (R-(+)-2-[4-
                                                                      (4-cyano-2-fluoro-
                                                                      phenoxy)phenoxy]propanoic acid) was the
                                                                      most prominent plasma fraction (90-94% of
                                                                      the dose for males and 75-81% for females
                                                                      regardless of dose).
                                                                     No parent compound or other metabolites
                                                                      were detected. The acid metabolite was the
                                                                      most common product in urine and feces 71-
                                                                      87% (urine) and 46-75% (feces) of the
                                                                      administered dose.
----------------------------------------------------------------------------------------------------------------
870.7600                                 Dermal Penetration (Rat)    Dermal absorption was 25-34% for the spray
                                                                      formulation and 11-16% for the EF-1218
                                                                      formulation following a 24 hour dermal
                                                                      dosing. Within 48 hours, excretion was
                                                                      >85% in the urine and <1% in the feces,
                                                                      which is consistent with metabolism to
                                                                      water soluble metabolites and subsequent
                                                                      urinary excretion.
                                                                     Levels tested: Four Fischer 344 rats were
                                                                      dermally dosed for 24 hours with \14\C-
                                                                      labeled DE-537 n-butyl ester and
                                                                      nonlabeled DE-537 n-butyl ester in two
                                                                      formulations 200 mg/mL test article in
                                                                      EF1218 (Clincher EDC with which DE-537 n-
                                                                      butyl ester is normally formulated) and a
                                                                      spray solution at 0.005, 1.0, or 1.8 mg/
                                                                      cm\2\.
----------------------------------------------------------------------------------------------------------------
Special Study                            Hepatocellular              In a subchronic oral toxicity study in rats
                                          Proliferation in Rats       (MRID 45000413), satellite rats dosed for
                                                                      4 weeks had hepatocellular hypertrophy and
                                                                      focal necrosis at all dose levels.
                                                                      Although multiple necrotic foci
                                                                      accompanied by inflammatory cells were
                                                                      graded very slight, and were not
                                                                      considered dose-related, this study was
                                                                      performed to explore these findings.
                                                                     An initial dramatic increase in DNA
                                                                      synthesis during the first week of
                                                                      treatment was followed by hepatocellular
                                                                      hypertrophy at subsequent observations.
                                                                      This was the reason for enlarged livers
                                                                      observed in XRD-537nBu-treated rats.
                                                                     Levels tested: 0, 3.0, 25, 100, or 400 mg/
                                                                      kg/day in the diet with sacrifices at 1,
                                                                      2, 4, and 13 weeks. One week prior to
                                                                      sacrifice, 10 L BrdU/hour was administered
                                                                      via an ALZET osmotic pump implanted
                                                                      subcutaneously. BrdU is a DNA stain used
                                                                      to quantify hepatocellular proliferation.
----------------------------------------------------------------------------------------------------------------

B. Toxicological Endpoints

    The dose at which no adverse effects are observed (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 lowest dose at which adverse effects of concern are 
identified (the LOAEL) 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. An UF of 100 is routinely used, 10X to account for 
interspecies differences and 10X for intra species differences.
    For dietary risk assessment (other than cancer) the Agency uses the 
UF to calculate an acute or chronic reference dose (acute RfD or 
chronic RfD) where the RfD is equal to the NOAEL divided by the 
appropriate UF (RfD = NOAEL/UF). Where an additional safety factor is 
retained due to concerns unique to the FQPA, this additional factor is 
applied to the RfD by dividing the RfD by such additional factor. The 
acute or chronic Population Adjusted Dose (aPAD or cPAD) is a 
modification of the RfD to accommodate this type of FQPA Safety Factor.
    For non-dietary risk assessments (other than cancer) the UF is used 
to determine the LOC. For example, when 100 is the appropriate UF (10X 
to account for interspecies differences and 10X for intraspecies 
differences) the LOC is 100. To estimate risk, a ratio of the NOAEL to 
exposures (margin of exposure (MOE) = NOAEL/exposure) is calculated and 
compared to the LOC.
    The linear default risk methodology (Q*) is the primary method 
currently used by the Agency to quantify carcinogenic risk. The Q* 
approach assumes that any amount of exposure will lead to some degree 
of cancer risk. A Q* is calculated and used to estimate risk which 
represents a probability of occurrence of additional cancer cases 
(e.g., risk is expressed as 1 x 10-\6\ or one in a million). 
Under certain specific circumstances, MOE calculations will be used for 
the carcinogenic risk assessment. In this non-linear approach, a 
``point of departure'' is identified below which carcinogenic effects 
are not expected. The point of departure is typically a NOAEL based on 
an endpoint related to cancer effects though it may be a different 
value derived from the dose response curve. To estimate risk, a ratio 
of the point of departure to exposure (MOEcancer = point of 
departure/exposures) is calculated. A summary of the toxicological 
endpoints for cyhalofop-butyl used for human risk assessment is shown 
in the following Table 3:

   Table 3.--Summary of Toxicological Dose and Endpoints for Cyhalofop-Butyl for Use in Human Risk Assessment
----------------------------------------------------------------------------------------------------------------
          Exposure Scenario                Dose (mg/kg/day)             Endpoint                  Study
----------------------------------------------------------------------------------------------------------------
Acute Dietary                          An appropriate endpoint attributable to a single dose was not identified.
                                                            An acute RfD was not established.
----------------------------------------------------------------------------------------------------------------

[[Page 38412]]

 
Chronic Dietary                        NOAEL (Female) = 0.99    Kidney effects in        Carcinogenicity in Mice
                                       FQPA SF = 1............   females including       MRID 45000418
                                                                 tubular dilatation,
                                                                 chronic
                                                                 glomerulonephritis,
                                                                 and hyaline casts at
                                                                 the LOAEL of 10.06 /
                                                                 10.28 mg/kg/day, M/F.
                                      --------------------------------------------------------------------------
                                        Chronic RfD = NOAEL/UF = 0.99 mg/kg/day/100 []0.01 mg/
                                                                         kg/day
 
                                             Chronic PAD = cRfD/FQPA SF = 0.01 mg/kg/day/1 = 0.01 mg/kg/day
----------------------------------------------------------------------------------------------------------------
Incidental Oral, Short-Term (1-30      NOAEL (Female) = 4.3     Enlarged kidneys in      Subchronic Feeding in
 days)                                 FQPA SF = 1............   females accompanied by   Mice
                                                                 swelling of the         MRID 45014706
                                                                 proximal tubule cells
                                                                 in 4/12 mice at the
                                                                 LOAEL of 14.1 mg/kg/
                                                                 day.
                                                                LOC = 100..............
--------------------------------------
Incidental Oral, Intermediate- Term
 (1-6 months)
----------------------------------------------------------------------------------------------------------------
Dermal, Short-Term (1-30 days)             No hazard has been identified to support quantification ofrisk. No
                                         systemic effects were observed in the 21-day dermal study in therat at
                                          doses up to 1000 mg/kg/day (limit dose). In addition, nodevelopmental
                                              effects were observed in the developmental toxicity studies.
--------------------------------------
 Dermal, Intermediate-Term (1-6
 months)
----------------------------------------------------------------------------------------------------------------
 Dermal, Long-Term\a\(>6 months)       NOAEL (Female) = 0.99    Kidney effects in        Carcinogenicity in Mice
                                       FQPA SF = 1............   females including       MRID 45000418
                                                                 tubular dilatation,
                                                                 chronic
                                                                 glomerulonephritis,
                                                                 and hyaline casts at
                                                                 the LOAEL of 10.06 /
                                                                 10.28 mg/kg/day, M/F.
                                                                LOC = 100..............
----------------------------------------------------------------------------------------------------------------
Inhalation, Short-Term\b\(1-30 days)   NOAEL (Female) = 4.3     Enlarged kidneys in      Subchronic Feeding in
                                       FQPA SF = 1............   females accompanied by   Mice
                                                                 swelling of the         MRID 45014706
                                                                 proximal tubule cells
                                                                 in 4/12 mice at the
                                                                 LOAEL of 14.1 mg/kg/
                                                                 day.
                                                                LOC = 100..............
--------------------------------------
Inhalation, Intermediate-Term\b\(1-6
 months)
----------------------------------------------------------------------------------------------------------------
Inhalation, Long-Term\b\(>6 months)    NOAEL (Female) = 0.99    Kidney effects in        Carcinogenicity in Mice
                                       FQPA SF = 1............   females including       MRID 45000418
                                                                 tubular dilatation,
                                                                 chronic
                                                                 glomerulonephritis,
                                                                 and hyaline casts at
                                                                 the LOAEL of 10.06 /
                                                                 10.28 mg/kg/day, M/F.
                                                                Target MOE = 100.......
----------------------------------------------------------------------------------------------------------------
Cancer                                 This herbicide has not been classified. The rat and mouse carcinogenicity
                                          studies are identified as data gaps. Since the doses tested in these
                                         studies were too low to assess the carcinogenic potential of cyhalofop-
                                            butyl, the cancer dietary risk assessment was conducted using the
                                        potency factor (Q1*) of 2.3 x 10-\1\ for the structural analog diclofop-
                                                                         methyl.
----------------------------------------------------------------------------------------------------------------
\a\Since an oral endpoint was identified, a 34% dermal absorption factor should be used in route-to-route
  extrapolations.
\b\Since an oral endpoint was identified, a default oral: inhalation absorption factor of 1 should be used in
  route-to-route extrapolations.
 
 

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. No tolerances have 
previously been established for the combined residues of cyhalofop-
butyl, in or on raw agricultural commodities. Risk assessments were 
conducted by EPA to assess dietary exposures from cyhalofop-butyl in 
food as follows:
    i. Acute exposure. Acute dietary risk assessments are performed for 
a food-

[[Page 38413]]

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. No toxicological endpoint attributable to a single exposure 
was identified in the available toxicology studies. No appropriate 
study available show any acute dietary effects of concern.
    ii. Chronic exposure. In conducting this chronic dietary risk 
assessment the Dietary Exposure Evaluation Model (DEEM\TM\) analysis 
evaluated the individual food consumption as reported by respondents in 
the USDA insert 1989-1992 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: Residue levels are at the recommended tolerances 
for rice and 100% of the crop rice is treated with cyhalofop-butyl. All 
sub-populations had dietary exposure values which represented <1% of 
the cPAD.
    iii. Cancer. The cancer dietary risk assessment was conducted using 
the potency factor (Q1*) of 2.3 x 10-\1\ for the structural 
analog diclofop-methyl since the dose levels in the rat and mouse 
carcinogenicity studies were too low to assess the carcinogenic 
potential of cyhalofop-butyl. In cancer studies with diclofop-methyl 
there are tumors at doses similar to those doses which caused no tumors 
in the cyhalofop-butyl studies. Hypothetical rat and mouse Q1* values 
were calculated on the assumption that tumor incidence might rapidly 
escalate at doses greater than those actually used in the submitted 
studies. When a hypothetical Q1* was calculated for cyhalofop-butyl by 
assigning increased tumors at doses above those actually tested, the 
results came out slightly less potent than the Q1* for diclofop-methyl 
. For risk assessment purposes the diclofop-methyl Q1* will not 
underestimate any possible cancer risk. A refined (Tier 3) 
deterministic cancer risk assessment was conducted. Inputs to the 
dietary exposure assessment included the anticipated residues of 0.0066 
ppm for rice grain from field trials and estimates that a maximum of 
17.6% of rice will be treated with cyhalofop-butyl. Based on the 
anticipated residue and the percent of the crop treated, the refined 
dietary cancer risk from residues in food is 6.2 x 10 -\8\.
    Section 408(b)(2)(E) 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 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. As required by section 408(b)(2)(E), EPA will 
issue a data call-in for information relating to anticipated residues 
to be submitted no later than 5 years from the date of issuance of this 
tolerance.
    Section 408(b)(2)(F) 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 percent crop 
treated (PCT) as required by section 408(b)(2)(F), EPA may require 
registrants to submit data on PCT.
    The Agency used percent crop treated (PCT) information in Table 4 
and Table 5 as follows.

                                              Table 4.--Southern States Estimated Percent Rice Crop Treated
--------------------------------------------------------------------------------------------------------------------------------------------------------
                Year                          2002                    2003                    2004                   2005                   2006
--------------------------------------------------------------------------------------------------------------------------------------------------------
EPA Estimate                         2                       4.3                     4.3                    5.02                   5.6
--------------------------------------------------------------------------------------------------------------------------------------------------------


                                                Table 5.--California Estimated Percent Rice Crop Treated
--------------------------------------------------------------------------------------------------------------------------------------------------------
                Year                          2002                    2003                    2004                   2005                   2006
--------------------------------------------------------------------------------------------------------------------------------------------------------
EPA Estimate                         6.7                     12.7                    13.2                   15.6                   17.6
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The Agency believes that the three conditions 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 market share was for cyhalofop-butyl on rice was projected based on 
current percent of crop treated with the existing alternative controls. 
The Agency is reasonably certain that the percentage of the food 
treated is not likely to be an underestimation. More importantly, EPA 
has taken steps to ensure this market share projection is not exceeded 
by imposing, as a condition of registration for cyhalofop-butyl under 
Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), 7 U.S.C. 
136 et seq., a production limit corresponding to the projection. As to 
Conditions 2 and 3, regional consumption information and consumption 
information for significant sub-populations is taken into account 
through EPA's computer-based model for evaluating the exposure of 
significant sub-populations 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 sub-population 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 cyhalofop-
butyl 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 cyhalofop-butyl in drinking 
water. Because the Agency does not have comprehensive monitoring data,

[[Page 38414]]

drinking water concentration estimates are made by reliance on 
simulation or modeling taking into account data on the physical 
characteristics of cyhalofop-butyl.
    The GENEEC model is not adequate for predicting the estimated 
environmental concentrations (EECs) for pesticide applications to rice. 
The Agency developed a model using available chemical and physical 
property data, to calculate the EECs for the use of cyhalofop-butyl on 
rice. The model was based on a hypothetical rice paddy, 1 hectare in 
size, flooded to a depth of 10 cm, with a sediment interaction zone of 
1 cm. Based on these dimensions there are one million liters of water 
and 100 cubic meters of active sediment in the paddy. The sediment is 
assumed to weigh 135,000 kg based on a bulk density of 1.35g/cc. This 
model was used for both dry and water seeded rice.
    The peak drinking water concentrations for the Gulf Coast and 
California are 137 and 36 ppb, respectively. The resulting chronic EECs 
(annual averages in Index Reservoir) are 14.2 and 3.7 ppb, 
respectively. The peak drinking water concentration for the Mississippi 
Valley is 119 ppb, and the chronic EEC annual average is 12.4 ppb. If 
the (normal) release is on day 78 (90 days from seedling), the peak is 
25 ppb and the annual average is 2.6 ppb.
    Based on this model and the SCI-GROW model the estimated 
environmentalconcentrations (EECs) of for acute exposures are estimated 
to be: In a water-seeded paddy 36 parts per billion (ppb) , and in a 
dry-seeded paddy 25 ppb for surface water and 0.16 ug/L ppb for ground 
water. The EECs for chronic exposures are estimated to be 3.7 ppb for 
water-seeded rice and 2.6 ppb for dry-seeded rice.
    None of these models include consideration of the impact processing 
(mixing, dilution, or treatment) of raw water for distribution as 
drinking water would likely have on the removal of pesticides from the 
source water. The primary use of these models by the Agency at this 
stage is to provide a coarse screen for sorting out pesticides for 
which it is highly unlikely that drinking water concentrations would 
ever exceed human health levels of concern.
    Since the models used are considered to be screening tools in the 
risk assessment process, the Agency does not use estimated 
environmental concentrations (EECs) from these models to quantify 
drinking water exposure and risk as a %RfD or %PAD. Instead drinking 
water levels of comparison (DWLOCs) are calculated and used as a point 
of comparison against the model estimates of a pesticide's 
concentration in water. DWLOCs are theoretical upper limits on a 
pesticide's concentration in drinking water in light of total aggregate 
exposure to a pesticide in food, and from residential uses. Since 
DWLOCs address total aggregate exposure to cyhalofop-butyl they are 
further discussed in the aggregate risk sections.
    Because EECs calculated using the above models exceeded the DWLOC 
regarding potential cancer risk, EPA undertook a further analysis of 
this estimate. It was determined that there was not sufficient reliable 
data to further refine these estimates. Therefore, the Agency required 
that the FIFRA label for cyhalofop-butyl mandate a holding time of 
seven days before the treated paddy water may be released to the 
environment. This 7-day holding time will result in the concentration 
of cyhalofop-butyl, expressed as an annual average (conc/365), falling 
below 0.15 ppb.
    3. From non-dietary exposure. The term ``residentialexposure'' 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).
    Cyhalofop-butyl is not registered for use on any sites that would 
result in residential exposure.
    4. Cumulative exposure to substances with a common mechanism 
oftoxicity. Section 408(b)(2)(D)(v) 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 does not have, at this time, available data to determine 
whether cyhalofop-butyl has a common mechanism of toxicity with other 
substances or how to include this pesticide in a cumulative risk 
assessment. Unlike other pesticides for which EPA has followed a 
cumulative risk approach based on a common mechanism of toxicity, 
cyhalofop-butyl 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 cyhalofop-butyl 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 final rule for Bifenthrin Pesticide Tolerances (62 FR 62961, 
November 26, 1997) (FRL-5754-7).

D. Safety Factor for Infants and Children

    1.In general. FFDCA section 408 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 that a different margin of safety will be safe 
for infants andchildren. Margins of safety are incorporated into EPA 
risk assessments either directly through use of a margin of exposure 
(MOE) analysis or through using uncertainty (safety) factors in 
calculating a dose level that poses no appreciable risk to humans.
    2. Prenatal and postnatal sensitivity. There is no indication of 
quantitative or qualitative increased susceptibility of rats or rabbits 
to in utero or postnatal exposure.
    3. Conclusion. There is a complete toxicity data base for 
cyhalofop-butyl and exposure data are complete or are estimated based 
on data that reasonably accounts for potential exposures. EPA 
determined that the 10X safety factor should be reduced to 1x in 
assessing the risk posed by this chemical because: (1) There is no 
indication of quantitative or qualitative increased susceptibility; (2) 
a developmental neurotoxicity study (DNT) is notrequired; (3) the 
dietary food and drinking water exposure assessments will not 
underestimate the potential exposures for infants and children; (4) 
there currently no registered or proposed residential (non-
occupational) uses of cyhalofop-butyl, and (5) the database pertaining 
to threshold effects on infants and children is complete.

E. Aggregate Risks and Determination of Safety

    To estimate total aggregate exposure to a pesticide from food, 
drinking water, and residential uses, the Agency calculates DWLOCs 
which are used as a point of comparison against the model estimates of 
a pesticide's concentration in water (EECs). DWLOC values are not 
regulatory standards for drinking water. DWLOCs are theoretical upper 
limits on a pesticide's concentration in drinking water in light of 
total aggregate exposure to a pesticide in food and residential uses. 
In calculating a DWLOC, the Agency determines how much of the 
acceptable exposure (i.e., the PAD) is available for exposure through 
drinking water [e.g., allowable chronic water

[[Page 38415]]

exposure (mg/kg/day) = cPAD - (average food + residential exposure)]. 
This allowable exposure through drinking water is used to calculate a 
DWLOC.
    A DWLOC will vary depending on the toxic endpoint, drinking water 
consumption, and body weights. Default body weights and consumption 
values as used by the USEPA Office of Water are used to calculate 
DWLOCs: 2L/70 kg (adult male), 2L/60 kg (adult female), and 1L/10 kg 
(child). Default body weights and drinking water consumption values 
vary on an individual basis. This variation will be taken into account 
in more refined screening-level andquantitative drinking water exposure 
assessments. Different populations will have different DWLOCs. 
Generally, a DWLOC is calculated for each type of risk assessment used: 
Acute, short-term, intermediate-term, chronic, and cancer.
    When EECs for surface water and groundwater are less than the 
calculatedDWLOCs, OPP concludes with reasonable certainty that 
exposures to the pesticide in drinking water (when considered along 
with other sources of exposure for which OPP has reliable data) would 
not result in unacceptable levels of aggregate human health risk at 
this time. Because OPP considers the aggregate risk resulting from 
multiple exposure pathways associated with apesticide's uses, levels of 
comparison in drinking water may vary as those uses change. If new uses 
are added in the future, OPP will reassess the potential impacts of 
residues of the pesticide in drinking water as a part of the aggregate 
risk assessment process.
    1. Acute risk. An appropriate endpoint attributable to a single 
dose was not identified. Therefore, cyhalofop-butyl is not expected to 
pose an acute risk.
    2. Chronic risk. For all population subgroups, the chronic DWLOC is 
greater than the chronic surface EEC, and there is no expectation of 
migration of cyhalofop-butyl residues to ground water, therefore, 
aggregate chronic (non cancer) exposure to cyhalofop-butyl is not 
expected to exceed the Agency's level of concern. There are no 
residential uses for cyhalofop-butyl that result in chronic residential 
exposure to cyhalofop-butyl. The DWLOCs for chronic risk are shown in 
Table 6 as follows:

                                      Table 6.--Chronic DWLOC Calculations
----------------------------------------------------------------------------------------------------------------
                                                                  Chronic Scenario
                                   -----------------------------------------------------------------------------
                                                              Max Chronic
      Population Subgroup\1\        cPAD mg/kg/    Chronic     Water Exp      Ground      Surface      Chronic
                                        day      Food Exp mg/    mg/kg/     Water EEC    Water EEC    DWLOC (g/
                                                  kg/day\2\      day\3\      (units)     (units)\4\    L)\4/5\
----------------------------------------------------------------------------------------------------------------
U.S. Population                            0.01     0.000007     0.009993                      14.2          350
----------------------------------------------------------------------------------------------------------------
All Infants                                0.01     0.000028     0.009972                      14.2          100
----------------------------------------------------------------------------------------------------------------
Children (1-6 years)                       0.01     0.000015     0.009985                      14.2          100
----------------------------------------------------------------------------------------------------------------
Children (7-12 years)                      0.01     0.000009     0.009991                      14.2          100
----------------------------------------------------------------------------------------------------------------
Females (13-50 years)                      0.01     0.000005     0.009995                      14.2          300
----------------------------------------------------------------------------------------------------------------
Males (13-19 years)                        0.01     0.000005     0.009995                      14.2          350
----------------------------------------------------------------------------------------------------------------
Males (20+ years)                          0.01     0.000006     0.009994                      14.2          350
----------------------------------------------------------------------------------------------------------------
Seniors (55+ years)                        0.01     0.000004     0.009996                      14.2          350
----------------------------------------------------------------------------------------------------------------
Non-hispanic/non-white/non-black           0.01     0.000018     0.009982                      14.2          350
----------------------------------------------------------------------------------------------------------------
\1\The Non-hispanic/non-white/non-black population was included in this table because it has the highest adult
  dietary exposure level. Body weights used to calculate the DWLOCs are 70 kg for adult males; 60 kg for adult
  females, and 10 kg for children <12 years.
\2\The chronic food exposure levels are for rice, the sole crop being considered for registration.
\3\Maximum Chronic Water Exposure (mg/kg/day) = [Chronic PAD (mg/kg/day) - Chronic Dietary Exposure (mg/kg/day)]
\4\This table presents the surface water EECs without taking into account the further reduction achieved by the
  mandated holding period. Even absent the holding period the predicted levels are well within the DWLOCs.
\5\Chronic DWLOC( g/L) = [maximum chronic water exposure (mg/kg/day) x body weight (kg)]/[water consumption (L/
  day)x 10-\3\ mg/ g]

    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).
    Cyhalofop-butyl 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).
    Cyhalofop-butyl 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. Cyhalofop-butyl is 
not registered for use on any sites that would result in residential 
exposure. The cancer dietary risk assessment was conducted using the 
potency factor (Q1*) of 2.3 x 10-\1\ for the structural 
analog diclofop-methyl since the dose levels in the rat and mouse 
carcinogenicity studies were too low to assess the carcinogenic 
potential of cyhalofop-butyl. In cancer studies with diclofop-methyl 
there are tumors at doses similar to those doses which resulted in no 
tumors in the cyhalofop-butyl studies. Hypothetical rat and mouse Q1* 
values were calculated on the assumption that tumor incidence might 
rapidly escalate at doses greater than those actually used in the 
submitted studies. These hypothetical Q1*s came out slightly less 
potent than the Q1* for diclofop-methyl. Thus, given that no data with 
cyhalofop-butyl

[[Page 38416]]

has indicated carcinogenic potential, use of the diclofop-methyl Q1* 
will produce a conservative (health-protective) estimate of cancer 
risk. Based on the anticipated residue and the percent of the crop 
treated, the refined dietary cancer risk from residues in food is 6.2 x 
10 -\8\. The cancer DWLOC for the general population is 
shown in the table below. With a water holding time of 7 days, the 
concentration of cyhalofop-butyl residues in paddy water, expressed as 
an annual average (concentration/365) will be less than 0.15 fg/L. 
Since this value is below the calculated cancer DWLOC of 0.44 fg/L, 
aggregate cancer risk to cyhalofop-butyl is not expected to exceed 
EPA's level of concern.

                                                           Table 7.--Cancer DWLOC Calculations
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                  Target Max        Chronic Food        Max Water
                 Population                        Q*       Negligible Risk   Exposure\2\ mg/kg/  Exposure mg/kg/   Exposure\3\ mg/kg/ Cancer DWLOC\4\(/
                                                                Level\1\             day                day                day                 L)
--------------------------------------------------------------------------------------------------------------------------------------------------------
U.S. Population                                      0.23         3 x 10-\6\       1.3 x 10-\5\         3 x 10-\7\      1.27 x 10-\5\               0.44
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\EPA has traditionally regarded risks in the range of the probability of one in one million as negligible, with risks as high as three in one million
  considered as falling within that range.
\2\ Target Maximum Exposure (mg/kg/day) = [negligible risk/Q*]
\3\ Maximum Water Exposure (mg/kg/day) = Target Maximum Exposure - Chronic Food Exposure (Note: There are no residential uses for this chemical.)
\4\ Cancer DWLOC(g/L) = [maximum water exposure (mg/kg/day) x body weight (kg)]/[water consumption (L) x 10-\3\ mg/g]\2\ Body weight (kg) = 70

    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 cyhalofop-butyl residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    Adequate enforcement methodology (example--gas chromatography) is 
available to enforce the tolerance expression. The method may be 
requested from: Calvin Furlow, PIRIB, IRSD (7502C), Office of Pesticide 
Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460; telephone number: (703) 305-5229; e-mail address: 
[email protected].

B. International Residue Limits

    There are no CODEX, Canadian, or Mexican tolerances/Maximum Residue 
Levelsfor cyhalofop-butyl residues. Thus, harmonization is not an issue 
at this time.

C. Conditions

    The following data gaps must be fulfilled: Subacute (28-day) 
inhalation toxicity study, a carcinogenicity study in rats, and a 
carcinogenicity study in mice.

V. Conclusion

    Therefore, time limited tolerances are established for combined 
residues of cyhalofop (cyhalofop-butyl plus cyhalofop-acid) and the di-
acid metabolite in or on rice grain at 0.03 ppm and rice straw 8.0 ppm.

VI. Objections and Hearing Requests

    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. Although the procedures in those 
regulations require some modification to reflect the amendments made to 
the FFDCA by the FQPA of 1996, EPA will continue to use those 
procedures, with appropriate adjustments, until the necessary 
modifications can be made. The new section 408(g) provides essentially 
the same process for persons to ``object'' to a regulation for an 
exemption from the requirement of a tolerance issued by EPA under new 
section 408(d), as was provided in the old FFDCA sections 408 and 409. 
However, the period for filing objections is now 60 days, rather than 
30 days.

A. What Do I Need to Do to File an Objection or Request a Hearing?

    You must file your objection or request a hearing on this 
regulation in accordance with the instructions provided in this unit 
and in 40 CFR part 178. To ensure proper receipt by EPA, you must 
identify docket ID number OPP-2002-0087 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 August 5, 
2002.
    1. Filing the request. Your objection must specify the specific 
provisions in the regulation that you object to, and the grounds for 
the objections (40 CFR 178.25). If a hearing is requested, the 
objections must include a statement of the factual issues(s) on which a 
hearing is requested, the requestor's contentions on such issues, and a 
summary of any evidence relied upon by the objector (40 CFR 178.27). 
Information submitted in connection with an objection or hearing 
request may be claimed confidential by marking any part or all of that 
information as CBI. Information so marked will not be disclosed except 
in accordance with procedures set forth in 40 CFR part 2. A copy of the 
information that does not contain CBI must be submitted for inclusion 
in the public record. Information not marked confidential may be 
disclosed publicly by EPA without prior notice.
    Mail your written request to: Office of the Hearing Clerk (1900), 
Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460. You may also deliver your request to the Office 
of the Hearing Clerk in Rm. C400, Waterside Mall, 401 M St., SW., 
Washington, DC 20460. The Office of the Hearing Clerk is open from 8 
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The 
telephone number for the Office of theHearing Clerk is (202) 260-4865.
    2. Tolerance fee payment. If you file an objection or request a 
hearing, you must also pay the fee prescribed by 40 CFR 180.33(i) or 
request a waiver of that fee pursuant to 40 CFR 180.33(m). You must 
mail the fee to: EPA Headquarters Accounting Operations Branch, Office 
of Pesticide Programs, P.O. Box 360277M, Pittsburgh, PA 15251. Please 
identify the fee submission by labeling it ``Tolerance Petition Fees.''
    EPA is authorized to waive any fee requirement ``when in the 
judgement of the Administrator such a waiver or refund is equitable and 
not contrary to the purpose of this subsection.'' For additional 
information regarding the waiver of these fees, you maycontact James 
Tompkins by phone at (703) 305-5697, by e-mail at[email protected], 
or by mailing a request for information to Mr. Tompkins

[[Page 38417]]

at Registration Division (7505C), Office of Pesticide Programs, 
Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460.
    If you would like to request a waiver of the tolerance objection 
fees, you must mail your request for such a waiver to: James Hollins, 
Information Resources and Services Division (7502C), Office of 
Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania 
Ave., NW., Washington, DC 20460.
    3. Copies for the Docket. In addition to filing an objection or 
hearing request with the Hearing Clerk as described in Unit VI.A., you 
should also send a copy of your request to the PIRIB for its inclusion 
in the official record that is described in Unit I.B.2. Mail your 
copies, identified by docket ID number OPP-2002-0087, to: Public 
Information and Records Integrity Branch, Information Resources and 
Services Division (7502C), Office of Pesticide Programs, Environmental 
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460. 
In person or by courier, bring a copy to the location of the PIRIB 
described in Unit I.B.2. You may also send an electronic copy of your 
request via e-mail to: [email protected]. Please use an ASCII file 
format and avoid the use of special characters and any form of 
encryption. Copies of electronic objections and hearing requests will 
also be accepted on disks in WordPerfect 6.1/8.0 or ASCII file format. 
Do not include any CBI in your electronic copy. You may also submit an 
electronic copy of your request at many Federal Depository Libraries.

B. When Will the Agency Grant a Request for a Hearing?

    A request for a hearing will be granted if the Administrator 
determines that the material submitted shows the following: There is a 
genuine and substantial issue of fact; there is a reasonable 
possibility that available evidence identified by the requestor would, 
if established resolve one or more of such issues in favor of the 
requestor, taking into account uncontested claims or facts to the 
contrary; and resolution of the factual issues(s) in the manner sought 
by the requestor would be adequate to justify the action requested (40 
CFR 178.32).

VII. Regulatory Assessment Requirements

    This final rule establishes a tolerance under FFDCA section 408(d) 
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 FFDCA section 408(d), 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 FFDCA section 408(n)(4). 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 ormore 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 therelationship 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.

VIII. Submission to Congress and the Comptroller General

    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.



[[Page 38418]]


    Dated: May 23, 2002.
James Jones,
Acting Director, Office of Pesticide Programs.

    Therefore, 40 CFR chapter I is amended as follows:

PART 180--[AMENDED]

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

    Authority: 21 U.S.C. 321(q), 346(a) and 374.

    2. Part 180 is amended by adding Sec. 180.579 to read as follows:


Sec. 180.579  Cyhalofop-butyl; tolerances for residues.

    (a) General. Time-limited tolerances are established for combined 
residues of cyhalofop (cyhalofop-butyl, R-(+)-n-butyl-2-(4(4-cyano-2- 
fluorophenoxy)-phenoxy)propionate, plus cyhalofop acid, R-(+)-2-(4(4-
cyano-2-fluorophenoxy)-phenoxy)propionic acid) and the di-acid 
metabolite, (2R)-4-[4-(1-carboxyethoxy)phenoxy]-3-fluorobenzoic acid, 
from the application of the herbicide cyhalofop-butyl in or on the 
following raw agricultural commodities:

------------------------------------------------------------------------
                                                          Expiration/
            Commodity              Parts per million    Revocation Date
------------------------------------------------------------------------
Rice, grain                       0.03                6/1/2007
Rice, straw                       8.0                 6/1/2007
------------------------------------------------------------------------

    (b) Section 18 emergency exemptions. [Reserved]
    (c) Tolerances with regional registrations. [Reserved]
    (d) Indirect or inadvertent residues. [Reserved]

[FR Doc. 02-13982 Filed 6-3-02; 8:45 am]
BILLING CODE 6560-50-S