Cloquintocet-mexyl; Pesticide Tolerance

Note: EPA no longer updates this information, but it may be useful as a reference or resource.

[Federal Register: June 22, 2000 (Volume 65, Number 121)]
[Rules and Regulations]
[Page 38757-38764]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr22jn00-15]

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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.

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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:
alston.treva@epa.gov.

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 µg/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 µg/plate) with or
without S9 activation. Negative
mutagen.
------------------------------------------------------------------------
870.5375 Human Lymphocytes in Human lymphocytes were exposed in
vitro. vitro up to 75 µg/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 µg/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 tompkins.jim@epa.gov,
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: opp-docket@epa.gov. 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

Cloquintocet-mexyl; Pesticide Tolerance

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