[Federal Register Volume 65, Number 121 (Thursday, June 22, 2000)]
[Rules and Regulations]
[Pages 38757-38764]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-15716]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-301010; FRL-6592-4]
RIN 2070-AB78


Cloquintocet-mexyl; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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

SUMMARY: This regulation establishes tolerances for the combined 
residues of the inert ingredient (herbicide safener) cloquintocet-mexyl 
and its acid metabolite in or on wheat grain, forage, hay, and straw. 
Novartis Crop Protection, Inc. requested this tolerance under the 
Federal Food, Drug, and Cosmetic Act, as amended by the Food Quality 
Protection Act of 1996.

DATES: This regulation is effective June 22, 2000. Objections and 
requests for hearings, identified by docket control number OPP-301010, 
must be received by EPA on or before August 21, 2000.

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 control number OPP-301010 in the 
subject line on the first page of your response.

FOR FURTHER INFORMATION CONTACT: By mail: Treva Alston, Registration 
Division (7505C), Office of Pesticide Programs, Environmental 
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460; 
telephone number: 703-308-8373; 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            potentially
                                                       affected entities
------------------------------------------------------------------------
Industry                          111                 Crop production
                                  112                 Animal production
                                  311                 Food manufacturing
                                  32532               Pesticide
                                                       manufacturing
------------------------------------------------------------------------

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

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

    1. Electronically.You may obtain electronic copies of this 
document, and certain other related documents that might be available 
electronically, from the EPA Internet Home Page at http://www.epa.gov/. 
To access this document, on the Home Page select ``Laws and 
Regulations'' and then look up the entry for this document under the 
``Federal Register--Environmental Documents.'' You can also go directly 
to the Federal Register listings at http://www.epa.gov/fedrgstr/.
    2. In person. The Agency has established an official record for 
this action under docket control number OPP-301010. 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

[[Page 38758]]

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 15, 1998 (63 FR 18417) (FRL-5781-
9), 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 104-170) announcing 
the filing of a pesticide petition (PP 7E4920) for tolerances by 
Novartis Crop Protection, Inc., P.O. Box 18300, Greensboro, North 
Carolina 27419. This notice included a summary of the petition prepared 
by Novartis Crop Protection, Inc., the petitioner. The petition was 
subsequently amended to increase the original proposed tolerances and 
an additional notice of filing was published in the Federal Register on 
April 19, 2000 (65 FR 20972). There were no comments received in 
response to the notice of filing.
    The April 19, 2000 (FRL-6554-3) petition requested that 40 CFR part 
180 be amended by establishing tolerances for combined residues of the 
inert ingredient (herbicide safener) cloquintocet-mexyl (acetic acid, 
[(5-chloro-8-quinolinyl)oxy]-, 1-methylhexyl ester) and its acid 
metabolite (5-chloro-8-quinolinoxyacetic acid), in or on wheat, grain 
at 0.1 parts per million (ppm); wheat, forage at 0.1 ppm; and wheat, 
hay at 0.1 ppm and wheat, straw at 0.1 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 cloquintocet-mexyl 
and its acid metabolite) on wheat, grain at 0.1 ppm; wheat, forage at 
0.1 ppm; wheat, hay at 0.1 ppm; and wheat, straw at 0.1 ppm. EPA's 
assessment of exposures and risks associated with establishing the 
tolerance follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its 
validity, completeness, and reliability as well as the relationship of 
the results of the studies to human risk. EPA has also considered 
available information concerning the variability of the sensitivities 
of major identifiable subgroups of consumers, including infants and 
children. The nature of the toxic effects caused by cloquintocet-mexyl 
are discussed in this unit 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.--Subchronic, Chronic and Other Toxicity
------------------------------------------------------------------------
     Guideline No./Study Type                      Results
------------------------------------------------------------------------
870.3100 28-Day Oral in Rodents...  NOAEL = 10 mg/kg/day
                                    LOAEL = 100 mg/kg/day based on
                                     microscopic kidney lesions.
------------------------------------------------------------------------
870.3100 28-Day Oral in Rodents...  NOAEL = 10 mg/kg/day (females only)
                                    LOAEL = 400 mg/kg/day based on
                                     transient decrease in body weight
                                     gain, microscopic alterations of
                                     the pituitary and thyroid and
                                     possible increased SGPT.
------------------------------------------------------------------------
870.3100 90-Day Oral Toxicity       NOAEL = males: 150 ppm (9.7 mg/kg/
 Rodents.                            day), females: 6,000 ppm (407) mg/
                                     kg/day
                                    LOAEL = males: 1000 ppm (63.9 mg/kg/
                                     day); females:  6,000
                                     ppm ( 407 mg/kg/day
                                     based on urinary bladder
                                     hyerplasia, kidney hydronephrosis
                                     and increased serum bilirubin in
                                     males.
------------------------------------------------------------------------
870.3150 90-Day Oral Toxicity in    NOAEL = 100 ppm (2.9 mg/kg/day in
 Nonrodents.                         males and 3.3 mg/kg/day in females)
                                    LOAEL = 1,000 ppm ( 30.2 mg/kg/day
                                     in males and females based on
                                     perivascular mixed inflammatory
                                     cell infiltrates and multicellular
                                     multifocal necrosis of the liver
                                     and thymic atrophy.
------------------------------------------------------------------------
870.3200 28-Day Dermal Toxicity...  NOAEL = 200 mg/kg/day
                                    LOAEL = 1,000 mg/kg/day based on
                                     mottled or reddish livers
                                     accompanied by histopathological
                                     changes including necrosis and
                                     fibrosis.
------------------------------------------------------------------------

[[Page 38759]]

 
870.3700a Prenatal Developmental    Maternal NOAEL = 100 mg/kg/day
 in Rodents.                        LOAEL = 400 mg/kg/day based on
                                     clinical signs and decrease in body
                                     weight gain and food consumption.
                                    Developmental NOAEL = 100 mg/kg/day
                                    LOAEL = 400 mg/kg/day based on the
                                     higher incidence of skeletal
                                     variants and decrease in fetal body
                                     weights in the high dose group.
------------------------------------------------------------------------
870.3700b Prenatal Developmental    Maternal NOAEL = 60 mg/kg/day
 in Nonrodents.                     LOAEL = 300 mg/kg/day based on
                                     maternal toxicity (death) in high
                                     dose group.
                                    Developmental NOAEL = 300 mg/kg/day
                                    LOAEL `` 300 mg/kg/day
------------------------------------------------------------------------
870.3800 Reproduction and           Parental/Systemic NOAEL = 5,000 ppm
 Fertility Effects.                  (males: 370.7 mg/kg/day; females:
                                     442.8 mg/kg/day
                                    LOAEL = 10,000 ppm (males: 721.7 mg/
                                     kg/day; females: 846.9 mg/kg/day
                                     based on decreased body weight,
                                     decreased food consumption, and
                                     pathological changes in the kidney
                                     (dilated renal pelvis, nephrolith,
                                     hydronephrosis, urethral
                                     constrictions) and urinary bladder
                                     (cytoliths, hyperemia, cystitis and
                                     urothelial hyperplasia).
                                    Reproductive NOAEL = 10,000 ppm
                                     (721.7 mg/kg/day)
                                    LOAEL = 10,000 ppm (721.7) mg/kg/
                                     day.
                                    Developmental NOAEL = 5,000 ppm
                                     (442.8) mg/kg/day
                                    LOAEL = 10,000 ppm (846.9 mg/kg/day
                                     based on decreased pup weight and
                                     dilated renal pelvis.
------------------------------------------------------------------------
870.4100b Chronic Toxicity in       NOAEL = 1,500 ppm (males: 43 mg/kg/
 Nonrodents.                         day; females: 45 mg/kg/day
                                    LOAEL = 15,000/10,000 ppm M: 196 F:
                                     216 mg/kg/day based on decreased
                                     body weight/weight gain and food
                                     consumption, anemia, increased
                                     serum iron, protein alterations,
                                     bone marrow hypoplasia and possible
                                     decreased testes/prostate weights
                                     and interstitial nephritis.
------------------------------------------------------------------------
870.4200 Carcinogenicity Mice.....  NOAEL = 1,000 ppm (males: 111 mg/kg/
                                     day; females: 102 mg/kg/day
                                    LOAEL = 5,000 ppm (males: 583 mg/kg/
                                     day; females: 520 mg/kg/day based
                                     on decreased body weight/weight
                                     gain in both sexes, urinary bladder
                                     lesions (chronic inflammation,
                                     ulceration, calculus and submucosa
                                     edema) in males and possible
                                     slightly increased water
                                     consumption in both sexes. Negative
                                     for oncogenicity.
------------------------------------------------------------------------
870.4300 Combined Chronic/          NOAEL = females: 100 ppm (4.3 mg/kg/
 oncogenicity in rat.                day); males: 1,000 ppm 36.4 mg/kg/
                                     day).
                                    LOAEL = females: 1,000 ppm (41.2 mg/
                                     kg/day); males: 2,000 ppm (81.5 mg/
                                     kg/day) based on increased
                                     incidence of thyroid follicular
                                     epithelial hyperplasia in females
                                     and based on lymphoid hyperplasis
                                     of the thymus in males.
------------------------------------------------------------------------
870.5100 Gene Mutation............  Testing up to 5,000 g/plate
                                     with or without S9 microsomes
                                     produces no evidence that
                                     cloquintocet-mexyl technical
                                     induced a mutagenic effect in any
                                     strain. Negative mutagen.
------------------------------------------------------------------------
 870.5200 Gene Mutation...........  There was no evidence of any
                                     mutagenic effect at any dose (up to
                                     500 g/plate) with or
                                     without S9 activation. Negative
                                     mutagen.
------------------------------------------------------------------------
870.5375 Human Lymphocytes in       Human lymphocytes were exposed in
 vitro.                              vitro up to 75 g/mL with
                                     or without S9 activation showed no
                                     evidence of inducing a cytogenetic
                                     effect at any dose. Negative
                                     mutagen.
------------------------------------------------------------------------
870.5395 Micronucleus Test........  Chinese hamsters dosed from 625 to
                                     2,000 mg/kg showed no evidence of
                                     inducing a clastogenic or aneugenic
                                     effect in either sex at any dose or
                                     sacrifice time. Negative mutagen.
------------------------------------------------------------------------
870.5550 DNA Repair Human           Cultured human fibrocytes were
 Fibroblasts.                        exposed in vitro to up to 60 g/mL for 5 hrs. and scored for
                                     silver grains in the nucleus. There
                                     was no evidence that cloquintocet-
                                     mexyl technical in the absence of
                                     S9 activation induced a genotoxic
                                     response.
------------------------------------------------------------------------
870.5550 DNA Repair Rat             Primary rat hepatocytes exposed to
 Hepatocytes.                        200 g/mL for 16-18 hours
                                     and scored for nuclear grain showed
                                     no evidence that cloquintocet-mexyl
                                     technical induced a genotoxic
                                     response. Negative mutagen.
------------------------------------------------------------------------
870.7485 Metabolism and             Absorption after a single low oral
 pharmcokinetics.                    dose (50 mg/kg bw), was between
                                     40.2% (males) and 35.6% (females).
                                     The major metabolite in the 0 to 24
                                     hour fecal and urinary pools was
                                     determined to be quinolinoxy acetic
                                     acid, accounting for approximately
                                     95% of the recovered radioactivity.
------------------------------------------------------------------------
870.7485 Metabolism and              The major metabolic pathway was
 pharmacokinetics.                   determined to be hydrolysis of the
                                     ester group, resulting in the
                                     formation of 5-chloro-8-quinolinoxy
                                     acetic acid. The major metabolic
                                     pathway was not significantly
                                     affected by sex, dose level or
                                     dosing regime.
------------------------------------------------------------------------

B. Toxicological Endpoints

    The dose at which no observed 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

[[Page 38760]]

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 intraspecies 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  106 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.

  Table 2.--Summary of Toxicological Dose and Endpoints for Cloquintocet-mexyl for Use in Human Risk Assessment
----------------------------------------------------------------------------------------------------------------
                                                                 FQPA SF \1\ and Level
          Exposure Scenario               Dose Used in Risk       of Concern for Risk    Study and Toxicological
                                            Assessment, UF             Assessment                Effects
----------------------------------------------------------------------------------------------------------------
Acute Dietary females 13-50 years of   NOAEL = 100 mg/kg/day.   FQPA SF = 1x             Developmental toxicity
 age.                                  UF =100................  aPAD = acute RfD/FQPA..   study in rats.
                                       Acute RfD = 1.0 mg/kg/   SF = 1.0 mg/kg/day.....  LOAEL = 400 mg/kg/day
                                        day.                                              based on higher
                                                                                          incidence of skeletal
                                                                                          variants and decrease
                                                                                          in fetal body weights.
----------------------------------------------------------------------------------------------------------------
Acute Dietary general population       None                     Not applicable           Not applicable.
 including infants and children.
----------------------------------------------------------------------------------------------------------------
Chronic Dietary all populations......  NOAEL = 4.3 mg/kg/day.   FQPA SF = 1x             Chronic/Oncogenicity
                                       UF = 100...............  cPAD = chronic RfD/FQPA   Toxicity-Rats LOAEL =
                                       Chronic RfD = 0.04 mg/   SF = 0.04 mg/kg/day....   41.2 mg/kg/day based
                                        kg/day.                                           on observation of
                                                                                          thyroid hyperplasia in
                                                                                          females.
----------------------------------------------------------------------------------------------------------------
Short-Term Dermal (1 to 7 days)......  Dermal NOAEL = 200 mg/   LOC for MOE = 100.       28-Day Dermal Toxicity-
                                        kg/day.                                           Rats.
                                                                                         LOAEL = 1,000 mg/kg/day
                                                                                          based on mottled or
                                                                                          reddish livers
                                                                                          accompanied by
                                                                                          histopatho- logical
                                                                                          changes including
                                                                                          necrosis and fibrosis
                                                                                          in two of five female
                                                                                          rats.
----------------------------------------------------------------------------------------------------------------
Intermediate-Term Dermal (1 week to    Dermal NOAEL = 200 mg/   LOC for MOE = 100.       28-Day Dermal Toxicity-
 several months).                       kg/day.                                           Rats LOAEL = 1,000 mg/
                                                                                          kg/day based on
                                                                                          mottled or reddish
                                                                                          livers accompanied by
                                                                                          histopathological
                                                                                          changes including
                                                                                          necrosis and fibrosis
                                                                                          in two of five female
                                                                                          rats.
----------------------------------------------------------------------------------------------------------------
Long-Term Dermal (several months to    None                     Not applicable           Based on the current
 lifetime).                                                                               use pattern, no long-
                                                                                          term dermal exposure
                                                                                          is expected to occur.
----------------------------------------------------------------------------------------------------------------
Short-Term Inhalation (1 to 7 days)..  Oral NOAEL = 100 mg/kg/  LOC for MOE = 100.       Developmental toxicity
                                        day.                                              study in rats LOAEL =
                                       absorption rate = 100%.                            400 mg/kg/day based on
                                                                                          higher incidence of
                                                                                          skeletal variants and
                                                                                          decrease in fetal body
                                                                                          weights in the high
                                                                                          dose group.
----------------------------------------------------------------------------------------------------------------
Intermediate-Term Inhalation (1 week   Oral NOAEL = 4.3 mg/kg/  LOC for MOE = 100        Chronic/Oncogenicity
 to several months).                    day.                                              Toxicity Rat.
                                       absorption rate = 100%.                           LOAEL = 41.2 mg/kg/day
                                                                                          based on observation
                                                                                          of thyroid hyperplasia
                                                                                          in females.
----------------------------------------------------------------------------------------------------------------
Long-Term Inhalation (several months   None                     Not applicable           Based on the current
 to lifetime).                                                                            use pattern, no long-
                                                                                          term inhalation
                                                                                          exposure is expected
                                                                                          to occur.
----------------------------------------------------------------------------------------------------------------
\1\ The reference to the FQPA Safety Factor refers to any additional safety factor retained due to concerns
  unique to the FQPA.

    In accordance with the Proposed EPA Weight-of-the-Evidence 
Categories, August 1999, the Agency classified cloquintocet-mexyl as 
``not likely to be a human carcinogen''. Carcinogenicity studies in 
rats and mice did not show increased incidence of spontaneous tumor 
formation. With negative mutagenicity test battery, it is suggested 
that cloquintocet-mexyl is not likely to be a human carcinogen.

[[Page 38761]]

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. No tolerances have 
previously been established for the combined residues of cloquintocet-
mexyl and its acid metabolite 5-chloro-8-quinolinoxyacetic acid. A risk 
assessment was conducted by EPA to assess dietary exposures from 
cloquintocet-mexyl and its acid metabolite in food as follows:
    i. Acute exposure. Acute dietary risk assessments are performed for 
a food-use pesticide if a toxicological study has indicated the 
possibility of an effect of concern occurring as a result of a one day 
or single exposure. The Agency has conducted Tier 1 acute food exposure 
assessments for cloquintocet-mexyl using the Dietary Exposure 
Evaluation Model (DEEM). This model incorporates consumption data 
generated in USDA's Continuing Surveys of Food Intakes by Individuals 
(CSFII), 1989-1992. For this acute food risk assessment, the entire 
distribution of single day food consumption events is combined with a 
single residue level (deterministic analysis ) to obtain a distribution 
of exposure in mg/kg/day. For a Tier 1 analysis, the Agency considers 
exposure at the 95th percentile of exposure. The following assumptions 
were made for the Tier 1 acute exposure assessment: (1) Residues of 
cloquintocet-mexyl and its acid metabolite would be present in/on wheat 
at the tolerance level (0.1 ppm); and (2) 100% of the wheat crop would 
be treated.
    ii. Chronic exposure. In conducting this chronic dietary risk 
assessment the Dietary Exposure Evaluation Model (DEEM) analysis 
evaluated the individual food consumption as reported by respondents in 
the USDA 1989-1992 nationwide Continuing Surveys of Food Intake by 
Individuals (CSFII) and accumulated exposure to the chemical for each 
commodity. For chronic food risk assessments, the three-day average of 
consumption for each sub-population is combined with residues in 
commodities to determine average exposure in mg/kg/day. The following 
assumptions were made for the chronic exposure assessments: (1) 
Residues of cloquintocet-mexyl and its acid metabolite would be present 
in/on wheat at the tolerance level (0.1 ppm); and (2) 100% of the wheat 
crop would be treated.
    2. Dietary exposure from drinking water. The Agency lacks 
sufficient monitoring exposure data to complete a comprehensive dietary 
exposure analysis and risk assessment for cloquintocet-mexyl and its 
acid metabolite 5-chloro-8-quinolinoxyacetic acid in drinking water. 
Because the Agency does not have comprehensive monitoring data, 
drinking water concentration estimates are made by reliance on 
simulation or modeling taking into account data on the physical 
characteristics of cloquintocet-mexyl and its acid metabolite.
    The Agency uses the Generic Estimated Environmental Concentration 
(GENEEC) to estimate pesticide concentrations in surface water and SCI-
GROW, which predicts pesticide concentrations in groundwater. In 
general, EPA will use GENEEC (a Tier 1 model) before using PRZM/EXAMS 
(a Tier 2 model) for a screening-level assessment for surface water. 
The GENEEC model is a subset of the PRZM/EXAMS model that uses a 
specific high-end runoff scenario for pesticides. GENEEC incorporates a 
farm pond scenario.
    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 cloquintocet-mexyl and its 
acid metabolite 5-chloro-quinolinoxyacetic acid they are further 
discussed in the aggregate risk sections below.
    Based on the GENEEC and SCI-GROW models the estimated environmental 
concentrations (EECs) of cloquintocet-mexyl in surface water and ground 
water for acute exposures are estimated to be 0.038 parts per billion 
(ppb) for surface water and 0.0060 ppb for ground water. The EECs for 
chronic exposures are estimated to be 0.0053 ppb for surface water and 
0.0060 ppb for ground water. The EECs for ground water for the acid 
metabolite for acute and chronic exposures are estimated to be 0.00017 
ppb. The EEC for surface water for acute exposure for the acid 
metabolite is estimated to be 0.031 ppb, while the chronic exposure is 
estimated to be 0.017 ppb for surface water.
    3. From non-dietary exposure. The term ``residential exposure'' is 
used in this document to refer to non-occupational, non-dietary 
exposure (e.g., for lawn and garden pest control, indoor pest control, 
termiticides, and flea and tick control on pets). Cloquintocet-mexyl is 
not registered for use on any sites that would result in residential 
exposure.
    4.Cumulative exposure to substances with a common mechanism of 
toxicity. 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 cloquintocet-mexyl 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, 
cloquintocet-mexyl 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 cloquintocet-mexyl 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).

D. Safety Factor for Infants and Children

    1. Safety factor for infants and children--i. 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 and children. 
Margins of safety are incorporated into EPA risk assessments either 
directly through use of a margin of exposure (MOE) analysis or through

[[Page 38762]]

using uncertainty (safety) factors in calculating a dose level that 
poses no appreciable risk to humans.
    ii. Prenatal and postnatal sensitivity. There was no evidence of 
developmental or reproductive toxicity for cloquintocet-mexyl. The data 
demonstrate no increased sensitivity of rats or rabbits to in utero or 
early post-natal exposure to cloquintocet-mexyl. NOAELs for maternal/
parental toxicity were either less than or equal to the NOAELs for 
fetal or reproductive toxicity.
    iii. Conclusion. There is a complete toxicity data base for 
cloquintocet-mexyl. Exposure data are complete or are estimated based 
on data that reasonably accounts for potential exposures. EPA has 
determined that the 10X safety factor to protect infants and children 
should be removed (i.e., reduced to 1X) because the toxicology database 
(i.e., developmental toxicity studies in rats and rabbits; 2-generation 
reproduction study in rats) is complete, and there is no indication of 
quantitative or qualitative increased susceptibility of rats or rabbits 
in the available toxicity data.

E. Aggregate Risks and Determination of Safety

    The following text is based on the assumption that water models 
were used to estimate residues in drinking water. If exposure to 
residues in drinking water is not expected, delete the following three 
paragraphs. If exposure is based on monitoring data, the text must be 
revised.
    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 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 and quantitative 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 
calculated DWLOCs, 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 a pesticide'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. Using the exposure assumptions discussed in this 
unit for acute exposure, the acute dietary exposure from food to 
cloquintocet-mexyl and its acid metabolite will occupy  1.0 % of the 
aPAD for females 13-50 years. In addition, there is potential for acute 
dietary exposure to cloquintocet-mexyl and its acid metabolite in 
drinking water. The acute DWLOC for the population subgroups females of 
child-bearing age is 30,000 ppb. After calculating the acute DWLOC and 
comparing the EECs for surface and ground water, EPA does not expect 
the aggregate exposure to exceed 100% of the aPAD since the DWLOC 
greatly exceeds the EEC.
    2. Chronic risk. Using the exposure assumptions described in this 
unit for chronic exposure, EPA has concluded that exposure to 
cloquintocet-mexyl and its acid metabolite from food will utilize  1 % 
of the cPAD for the U.S. population, infants ( 1 year), and male and 
female adult populations. Exposure from food will utilize 1 % of the 
cPAD for children (1-6) and (7-12 years). There are no residential uses 
for cloquintocet-mexyl that result in chronic residential exposure.

          Table 3.-- Aggregate Risk Assessment for Chronic (Non-Cancer) Exposure to cloquintocet-mexyl
----------------------------------------------------------------------------------------------------------------
                                                                             Surface       Ground
            Population Subgroup \1\              cPAD mg/kg/     % cPAD     Water EEC    Water EEC     Chronic
                                                     day         (Food)       (ppb)        (ppb)     DWLOC (ppb)
----------------------------------------------------------------------------------------------------------------
U.S. Population................................         0.04          1.0       0.0053       0.0060        1,400
Children 1-6...................................         0.04          1.0       0.0053       0.0060          400
Females 13+ Nursing............................         0.04          1.0       0.0053       0.0060        1,200
Males 13-19....................................         0.04          1.0       0.0053       0.0060       1,400
----------------------------------------------------------------------------------------------------------------
\1\ For all population subgroups, EPA does not expect the aggregate exposure to exceed 100% of a cPAD since the
  DWLOC greatly exceeds the EEC.

    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).
    Cloquintocet-mexyl 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). There are no 
established residential uses for cloquintocet-mexyl.
    Cloquintocet-mexyl 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.Cloquintocet-mexyl is 
classified as ``not likely'' to be a human carcinogen. Therefore, 
cloquintocet-

[[Page 38763]]

mexyl is not expected to pose a cancer risk.
    6. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
to the general population, and to infants and children from aggregate 
exposure to residues of cloquintocet-mexyl and its acid metabolite.

IV. Other Considerations

A. Analytical Enforcement Methodology

    The petitioner has proposed residue analytical methods for 
tolerance enforcement that use high performance liquid chromatography 
with UV detection (HPLC-UV). These methods are currently being 
validated by the Analytical Chemistry Branch laboratories, BEAD 
(7503C), Office of Pesticide Programs. Upon successful completion of 
the EPA validation, these methods will be forwarded to FDA for 
publication in a future revision of the Pesticide Analytical Manual. 
Vol-II (PAM-II). Prior to publication in PAM-II and upon request, the 
methods will be available prior to the harvest season from the 
Analytical Chemistry Branch (ACB), BEAD (7503C), Environmental Science 
Center, 701 Mapes Road, Fort George G. Meade, MD 20755-5350; contact 
Francis D. Griffith, Jr., telephone (410) 305-2905, e-mail 
griffith.francis @epa.gov. The analytical standards for these methods 
are also available from the EPA National Pesticide Standard Repository 
at the same location.

B. International Residue Limits

    There are no Codex, Canadian, or Mexican tolerances for 
cloquintocet-mexyl on wheat. Therefore, no compatibility issues exist.

C. Conditions

    The following residue chemistry data gaps have been identified for 
cloquintocet mexyl: (1) additional wheat metabolism data; (2) 
additional information on meat, milk, poultry, and egg analyses; (3) 
storage stability data; and (4) additional field trial residue studies. 
Because of these deficiencies, the Agency incorporated several 
conservative assumptions into the risk assessment for cloquintocet-
mexyl. The Agency believes that the available data and risk assessment 
support the determination that there is a reasonable certainty of no 
harm and the establishment of permanent tolerances for cloquintocet-
mexyl.
    Cloquintocet-mexyl will be used with the active ingredient, 
clodinafop-propargyl. The registration of clodinafop-propargyl will be 
time-limited and conditional upon submission of additional information/
data to satisfy certain toxicology, residue chemistry, ecological 
effects, and environmental fate data deficiencies. Several guideline 
requirements are either data gaps or are only partially fulfilled, and 
the additional information is required to confirm and/or refine the 
parameters of the Agency's risk assessment. The required data for both 
cloquintocet-mexyl and clodinafop-propargyl must be submitted to 
maintain this registration.

V. Conclusion

    Therefore, the tolerances are established for combined residues of 
cloquintocet-mexyl (acetic acid, [(5-chloro-8-quinolinyl)oxy]-, 1-
methylhexyl ester) and its acid metabolite (5-chloro-8-quinolinoxy 
acetic acid), in or on wheat, grain at 0.1 ppm (parts per million); 
wheat, forage at 0.1 ppm; wheat, hay at 0.1 ppm; and wheat, straw at 
0.1 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 control number OPP-301010 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 
21, 2000.
    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 the Hearing 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 
judgment 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 may contact James 
Tompkins by phone at (703) 305-5697, by e-mail at [email protected], 
or by mailing a request for information to Mr. Tompkins 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.

[[Page 38764]]

    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 control number OPP-301010, 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 file format 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). 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 prior consultation as specified by Executive Order 
13084, entitled Consultation and Coordination with Indian Tribal 
Governments (63 FR 27655, May 19, 1998); special considerations as 
required by Executive Order 12898, entitled Federal Actions to Address 
Environmental Justice in Minority Populations and Low-Income 
Populations (59 FR 7629, February 16, 1994); or require 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).

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.

    Dated: June 6, 2000.
Susan B. Hazen
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), (346a) and 371.


    2. Section 180.560 is added to read as follows:


Sec. 180.560  Cloquintocet-mexyl; tolerances for residues.

    (a) General. Tolerances are established for the combined residues 
of cloquintocet-mexyl (acetic acid, [(5-chloro-8-quniolinyl)oxy]-, 1-
methylhexyl ester)(CAS Reg. No. 99607-70-2) and its acid metabolite (5-
chloro-8-quinlinoxyacetic acid) when used as an inert ingredient 
(safener) in pesticide formulations containing the herbicide, 
clodinafop-propargyl in a 1:4 ratio of safener to active ingredient in 
or on the following food commodities:

------------------------------------------------------------------------
                                                               Parts per
                          Commodity                             million
------------------------------------------------------------------------
Wheat, forage................................................        0.1
Wheat, straw.................................................        0.1
Wheat, hay...................................................        0.1
Wheat, grain.................................................        0.1
------------------------------------------------------------------------

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

[FR Doc. 00-15716 Filed 6-21-00; 8:45 am]
BILLING CODE 6560-50-F