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Fluroxypyr - Pesticide Tolerance 7/98

ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-300688; FRL-6018-4]
RIN 2070-AB78
Fluroxypyr 1-Methylheptyl Ester; Pesticide Tolerances for
Emergency Exemptions
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes time-limited tolerances for the
combined residues of fluroxypyr 1-methylheptyl ester and its metabolite
fluroxypyr in or on wheat, barley, field corn, and sweet corn. This
action is in response to EPA's granting of emergency exemptions under
section 18 of the Federal Insecticide, Fungicide, and Rodenticide Act
authorizing use of the pesticide on wheat, barley, field corn, and
sweet corn. This regulation establishes a maximum permissible level for
residues of fluroxypyr 1-methylheptyl ester and its metabolite
fluroxypyr in these food commodities pursuant to section 408(l)(6) of
the Federal Food, Drug, and Cosmetic Act, as amended by the Food
Quality Protection Act of 1996. These tolerances will expire and are
revoked on December 1, 1999.

DATES: This regulation is effective August 5, 1998. Objections and
requests for hearings must be received by EPA on or before October 5,
1998.

ADDRESSES: Written objections and hearing requests, identified by the
docket control number, [OPP-300688], must be submitted to: Hearing
Clerk (1900), Environmental Protection Agency, Rm. M3708, 401 M St.,
SW., Washington, DC 20460. Fees accompanying objections and hearing
requests shall be labeled "Tolerance Petition Fees" and forwarded to:
EPA Headquarters Accounting Operations Branch, OPP (Tolerance Fees),
P.O. Box 360277M, Pittsburgh, PA 15251. A copy of any objections and
hearing requests filed with the Hearing Clerk identified by the docket
control number, [OPP-300688], must also be submitted to: Public
Information and Records Integrity Branch, Information Resources and
Services Division (7502C), Office of Pesticide Programs, Environmental
Protection Agency, 401 M St., SW., Washington, DC 20460. In person,
bring a copy of objections and hearing requests to Rm. 119, CM #2, 1921
Jefferson Davis Hwy., Arlington, VA.

[[Page 41728]]

    A copy of objections and hearing requests filed with the Hearing
Clerk may also be submitted electronically by sending electronic mail
(e-mail) to: opp-docket@epamail.epa.gov. Copies of objections and
hearing requests must be submitted as an ASCII file avoiding the use of
special characters and any form of encryption. Copies of objections and
hearing requests will also be accepted on disks in WordPerfect 5.1/6.1
file format or ASCII file format. All copies of objections and hearing
requests in electronic form must be identified by the docket control
number [OPP-300688]. No Confidential Business Information (CBI) should
be submitted through e-mail. Electronic copies of objections and
hearing requests on this rule may be filed online at many Federal
Depository Libraries.

FOR FURTHER INFORMATION CONTACT: By mail: Andrew Ertman, Registration
Division (7505C), Office of Pesticide Programs, Environmental
Protection Agency, 401 M St., SW., Washington, DC 20460. Office
location, telephone number, and e-mail address: Crystal Mall #2, 1921
Jefferson Davis Hwy., Arlington, VA, (703) 308-9367, e-mail:
ertman.andrew@epamail.epa.gov.

SUPPLEMENTARY INFORMATION: EPA, on its own initiative, pursuant to
section 408(e) and (l)(6) of the Federal Food, Drug, and Cosmetic Act
(FFDCA), 21 U.S.C. 346a(e) and (l)(6), is establishing tolerances for
the combined residues of the herbicide fluroxypyr 1-methylheptyl ester
and its metabolite fluroxypyr, in or on wheat and barley, grain at 0.5
parts per million (ppm); wheat, forage at 12.0 ppm; wheat and barley,
hay at 20.0 ppm; wheat and barley, straw at 12.0 ppm; aspirated grain
fractions at 0.6 ppm; corn, sweet, K + CWHR at 0.05 ppm; corn, sweet,
forage at 2.0 ppm; corn, sweet, stover at 2.5 ppm; corn, field, grain
at 0.05 ppm; corn, field, forage at 2.0 ppm; corn, field, stover at 2.5
ppm; meat, fat, and meat byproducts (except kidney) of cattle, goats,
hogs, horses, and sheep 0.1 ppm; kidney of cattle, goats, hogs, horses,
and sheep 0.5 ppm; milk 0.1 ppm. These tolerances will expire and are
revoked on December 1, 1999. EPA will publish a document in the Federal
Register to remove the revoked tolerances from the Code of Federal
Regulations.

I. Background and Statutory Authority

    The Food Quality Protection Act of 1996 (FQPA) (Pub. L. 104-170)
was signed into law August 3, 1996. FQPA amends both the Federal Food,
Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 301 et seq., and the Federal
Insecticide, Fungicide, and Rodenticide Act (FIFRA), 7 U.S.C. 136 et
seq. The FQPA amendments went into effect immediately. Among other
things, FQPA amends FFDCA to bring all EPA pesticide tolerance-setting
activities under a new section 408 with a new safety standard and new
procedures. These activities are described below and discussed in
greater detail in the final rule establishing the time-limited
tolerance associated with the emergency exemption for use of
propiconazole on sorghum (61 FR 58135, November 13, 1996)(FRL-5572-9).
    New 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. . . ."
    Section 18 of FIFRA authorizes EPA to exempt any Federal or State
agency from any provision of FIFRA, if EPA determines that "emergency
conditions exist which require such exemption." This provision was not
amended by FQPA. EPA has established regulations governing such
emergency exemptions in 40 CFR part 166.
    Section 408(l)(6) of the FFDCA requires EPA to establish a time-
limited tolerance or exemption from the requirement for a tolerance for
pesticide chemical residues in food that will result from the use of a
pesticide under an emergency exemption granted by EPA under section 18
of FIFRA. Such tolerances can be established without providing notice
or period for public comment.
    Because decisions on section 18-related tolerances must proceed
before EPA reaches closure on several policy issues relating to
interpretation and implementation of the FQPA, EPA does not intend for
its actions on such tolerance to set binding precedents for the
application of section 408 and the new safety standard to other
tolerances and exemptions.

II. Emergency Exemption for Fluroxypyr 1-Methylheptyl Ester on
Wheat, Barley, Field Corn, and Sweet Corn and FFDCA Tolerances

    Fluroxypyr 1-methylheptyl ester was requested to control volunteer
potatoes. It was stated that volunteer potatoes are one of the main
sources for overwintering of obligate pests of potatoes including late
blight and leafroll virus. The populations of volunteer potatoes are
closely related to the severity of winter temperature conditions. When
soil temperatures reach levels low enough to freeze tubers remaining in
the soil after harvest, volunteer potatoes are generally not a problem.
However, following mild winters, volunteer potatoes are always present
in crops following potatoes in the rotation. Sustained temperatures of
28 deg.F or less are required to kill the tubers and prevent emergence
of volunteers.
    The applicants stated that volunteer potato populations will be
high in 1998 and that volunteer potato plants will act as a source of
infection from both late blight and leafroll virus. EPA has authorized
under FIFRA section 18 the use of fluroxypyr 1-methylheptyl ester on
wheat, barley, field corn, and sweet corn for control of volunteer
potatoes in Idaho, Michigan, Montana, Washington and kochia in North
Dakota, and South Dakota. After having reviewed the submission, EPA
concurs that emergency conditions exist for these States.
    As part of its assessment of this emergency exemption, EPA assessed
the potential risks presented by residues of fluroxypyr 1-methylheptyl
ester in or on wheat, barley, field corn, and sweet corn. In doing so,
EPA considered the new safety standard in FFDCA section 408(b)(2), and
EPA decided that the necessary tolerances under FFDCA section 408(l)(6)
would be consistent with the new safety standard and with FIFRA section
18. Consistent with the need to move quickly on the emergency exemption
in order to address an urgent non-routine situation and to ensure that
the resulting food is safe and lawful, EPA is issuing these tolerances
without notice and opportunity for public comment under section 408(e),
as provided in section 408(l)(6). Although these tolerances will expire
and are revoked on December 1, 1999, under FFDCA section 408(l)(5),
residues of the pesticide not in excess of the amounts specified in the
tolerances remaining in or on wheat, barley, field corn, and sweet corn
after that date will not be unlawful, provided the pesticide is applied
in a manner that was lawful

[[Page 41729]]

under FIFRA, and the residues do not exceed a level that was authorized
by this tolerance at the time of that application. EPA will take action
to revoke these tolerances earlier if any experience with, scientific
data on, or other relevant information on this pesticide indicate that
the residues are not safe.
    Because these tolerances are being approved under emergency
conditions EPA has not made any decisions about whether fluroxypyr 1-
methylheptyl ester meets EPA's registration requirements for use on
wheat, barley, field corn, and sweet corn or whether permanent
tolerances for these uses would be appropriate. Under these
circumstances, EPA does not believe that these tolerances serve as a
basis for registration of fluroxypyr 1-methylheptyl ester by a State
for special local needs under FIFRA section 24(c). Nor do these
tolerances serve as the basis for any State other than Idaho, Michigan,
Montana, Washington, North Dakota, and South Dakota to use this
pesticide on these crops under section 18 of FIFRA without following
all provisions of section 18 as identified in 40 CFR part 166. For
additional information regarding the emergency exemption for fluroxypyr
1-methylheptyl ester, contact the Agency's Registration Division at the
address provided above.

III. Risk Assessment and Statutory Findings

    EPA performs a number of analyses to determine the risks from
aggregate exposure to pesticide residues. First, EPA determines the
toxicity of pesticides based primarily on toxicological studies using
laboratory animals. These studies address many adverse health effects,
including (but not limited to) reproductive effects, developmental
toxicity, toxicity to the nervous system, and carcinogenicity. Second,
EPA examines exposure to the pesticide through the diet (e.g., food and
drinking water) and through exposures that occur as a result of
pesticide use in residential settings.

A. Toxicity

    1. Threshold and non-threshold effects. For many animal studies, a
dose response relationship can be determined, which provides a dose
that causes adverse effects (threshold effects) and doses causing no
observed effects (the "no-observed effect level" or "NOEL").
    Once a study has been evaluated and the observed effects have been
determined to be threshold effects, EPA generally divides the NOEL from
the study with the lowest NOEL by an uncertainty factor (usually 100 or
more) to determine the Reference Dose (RfD). The RfD is a level at or
below which daily aggregate exposure over a lifetime will not pose
appreciable risks to human health. An uncertainty factor (sometimes
called a "safety factor") of 100 is commonly used since it is assumed
that people may be up to 10 times more sensitive to pesticides than the
test animals, and that one person or subgroup of the population (such
as infants and children) could be up to 10 times more sensitive to a
pesticide than another. In addition, EPA assesses the potential risks
to infants and children based on the weight of the evidence of the
toxicology studies and determines whether an additional uncertainty
factor is warranted. Thus, an aggregate daily exposure to a pesticide
residue at or below the RfD (expressed as 100% or less of the RfD) is
generally considered acceptable by EPA. EPA generally uses the RfD to
evaluate the chronic risks posed by pesticide exposure. For shorter
term risks, EPA calculates a margin of exposure (MOE) by dividing the
estimated human exposure into the NOEL from the appropriate animal
study. Commonly, EPA finds MOEs lower than 100 to be unacceptable. This
100-fold MOE is based on the same rationale as the 100-fold uncertainty
factor.
    Lifetime feeding studies in two species of laboratory animals are
conducted to screen pesticides for cancer effects. When evidence of
increased cancer is noted in these studies, the Agency conducts a
weight of the evidence review of all relevant toxicological data
including short-term and mutagenicity studies and structure activity
relationship. Once a pesticide has been classified as a potential human
carcinogen, different types of risk assessments (e.g., linear low dose
extrapolations or MOE calculation based on the appropriate NOEL) will
be carried out based on the nature of the carcinogenic response and the
Agency's knowledge of its mode of action.
    2. Differences in toxic effect due to exposure duration. The
toxicological effects of a pesticide can vary with different exposure
durations. EPA considers the entire toxicity data base, and based on
the effects seen for different durations and routes of exposure,
determines which risk assessments should be done to assure that the
public is adequately protected from any pesticide exposure scenario.
Both short and long durations of exposure are always considered.
Typically, risk assessments include "acute," "short-term,"
"intermediate term," and "chronic" risks. These assessments are
defined by the Agency as follows.
    Acute risk, by the Agency's definition, results from 1-day
consumption of food and water, and reflects toxicity which could be
expressed following a single oral exposure to the pesticide residues.
High end exposure to food and water residues are typically assumed.
    Short-term risk results from exposure to the pesticide for a period
of 1-7 days, and therefore overlaps with the acute risk assessment.
Historically, this risk assessment was intended to address primarily
dermal and inhalation exposure which could result, for example, from
residential pesticide applications. However, since enaction of FQPA,
this assessment has been expanded to include both dietary and non-
dietary sources of exposure, and will typically consider exposure from
food, water, and residential uses when reliable data are available. In
this assessment, risks from average food and water exposure, and high-
end residential exposure, are aggregated. High-end exposures from all
three sources are not typically added because of the very low
probability of this occurring in most cases, and because the other
conservative assumptions built into the assessment assure adequate
protection of public health. However, for cases in which high-end
exposure can reasonably be expected from multiple sources (e.g.
frequent and widespread homeowner use in a specific geographical area),
multiple high-end risks will be aggregated and presented as part of the
comprehensive risk assessment/characterization. Since the toxicological
endpoint considered in this assessment reflects exposure over a period
of at least 7 days, an additional degree of conservatism is built into
the assessment; i.e., the risk assessment nominally covers 1-7 days
exposure, and the toxicological endpoint/NOEL is selected to be
adequate for at least 7 days of exposure. (Toxicity results at lower
levels when the dosing duration is increased.)
    Intermediate-term risk results from exposure for 7 days to several
months. This assessment is handled in a manner similar to the short-
term risk assessment.
    Chronic risk assessment describes risk which could result from
several months to a lifetime of exposure. For this assessment, risks
are aggregated considering average exposure from all sources for
representative population subgroups including infants and children.

[[Page 41730]]

B. Aggregate Exposure

    In examining aggregate exposure, FFDCA section 408 requires that
EPA take into account available and reliable information concerning
exposure from the pesticide residue in the food in question, residues
in other foods for which there are tolerances, residues in groundwater
or surface water that is consumed as drinking water, and other non-
occupational exposures through pesticide use in gardens, lawns, or
buildings (residential and other indoor uses). Dietary exposure to
residues of a pesticide in a food commodity are estimated by
multiplying the average daily consumption of the food forms of that
commodity by the tolerance level or the anticipated pesticide residue
level. The Theoretical Maximum Residue Contribution (TMRC) is an
estimate of the level of residues consumed daily if each food item
contained pesticide residues equal to the tolerance. In evaluating food
exposures, EPA takes into account varying consumption patterns of major
identifiable subgroups of consumers, including infants and children.The
TMRC is a "worst case" estimate since it is based on the assumptions
that food contains pesticide residues at the tolerance level and that
100% of the crop is treated by pesticides that have established
tolerances. If the TMRC exceeds the RfD or poses a lifetime cancer risk
that is greater than approximately one in a million, EPA attempts to
derive a more accurate exposure estimate for the pesticide by
evaluating additional types of information (anticipated residue data
and/or percent of crop treated data) which show, generally, that
pesticide residues in most foods when they are eaten are well below
established tolerances.
    Percent of crop treated estimates are derived from federal and
private market survey data. Typically, a range of estimates are
supplied and the upper end of this range is assumed for the exposure
assessment. By using this upper end estimate of percent of crop
treated, the Agency is reasonably certain that exposure is not
understated for any significant subpopulation group. Further, regional
consumption information is taken into account through EPA's computer-
based model for evaluating the exposure of significant subpopulations
including several regional groups, to pesticide residues. For this
pesticide, the most highly exposed population subgroup (non-nursing
infants <1 year old) was not regionally based.

IV. 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
fluroxypyr 1-methylheptyl ester and to make a determination on
aggregate exposure, consistent with section 408(b)(2), for time-limited
tolerances for combined residues of fluroxypyr 1-methylheptyl ester and
its metabolite fluroxypyr on wheat and barley, grain at 0.5 ppm; wheat,
forage at 12.0 ppm; wheat and barley, hay at 20.0 ppm; wheat and
barley, straw at 12.0 ppm; aspirated grain fractions at 0.6 ppm; corn,
sweet, K + CWHR at 0.05 ppm; corn, sweet, forage at 2.0 ppm; corn,
sweet, stover at 2.5 ppm; corn, field, grain at 0.05 ppm; corn, field,
forage at 2.0 ppm; corn, field, stover at 2.5 ppm; meat, fat, and meat
byproducts (except kidney) of cattle, goats, hogs, horses, and sheep
0.1 ppm; kidney of cattle, goats, hogs, horses, and sheep 0.5 ppm; milk
0.1 ppm. EPA's assessment of the dietary 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 fluroxypyr 1-
methylheptyl ester are discussed below.
    1. Acute toxicity. For acute dietary risk assessment, the Agency is
using a NOEL of 100 milligrams/kilogram/day (mg/kg/day), based on
developmental effects (postimplantation loss) at the lowest effect
level (LEL) of 250 mg/kg/day, from a developmental study in rabbits.
This risk assessment will evaluate acute dietary risk to females 13+
years, the population subgroup of concern. An MOE of 300 is required
because of FQPA considerations.
    2. Short - and intermediate - term toxicity. For short and
intermediate-term risk assessment, the Agency is using a NOEL of 100
mg/kg/day, based on developmental effects (postimplantation loss) at
the LEL of 250 mg/kg/day, from a developmental study in rabbits. An MOE
of 300 is required because of FQPA considerations.
    3. Chronic toxicity. EPA has established the RfD for fluroxypyr 1-
methylheptyl ester at 0.50 mg/kg/day. The RfD was established based on
a 4-week range finding study in dogs with a NOEL of 50 mg/kg/day and an
uncertainty factor of 100 based on histopathological lesions in the
kidneys, decreased testes weight, and increased adrenal weight at the
LEL of 150 mg/kg/day.
    4. Carcinogenicity. Fluroxypyr has been classified as a "not
likely" carcinogenic chemical by the Agency.

B. Exposures and Risks

    1. From food and feed uses. No tolerances have been established for
residues of fluroxypyr 1-methylheptyl ester. Risk assessments were
conducted by EPA to assess dietary exposures and risks from fluroxypyr
1-methylheptyl ester as follows:
    i.  Acute exposure and risk. 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 acute dietary (food only) risk
assessment used the TMRC. The exposure estimate for females (13+ years)
results in a dietary (food only) MOE of 50,000. This should be viewed
as a conservative risk estimate; refinement using anticipated residue
values and percent crop-treated data in conjunction with Monte Carlo
analysis would result in a lower acute dietary exposure estimate.
    ii. Chronic exposure and risk. In conducting this chronic dietary
risk assessment, EPA has made very conservative assumptions -- 100% of
wheat, barley, field corn, and sweet corn and all other commodities
having fluroxypyr 1-methylheptyl ester tolerances will contain
fluroxypyr 1-methylheptyl ester residues and those residues would be at
the level of the tolerance -- which result in an overestimation of
human dietary exposure. Thus, in making a safety determination for this
tolerance, HED is taking into account this conservative exposure
assessment.
    The existing fluroxypyr 1-methylheptyl ester tolerances (published,
pending, and including the necessary section 18 tolerances) result in a
TMRC that is equivalent to the following percentages of the RfD:

------------------------------------------------------------------------
                    Population Subgroup                          %RfD
------------------------------------------------------------------------
U.S. Population (48 States)................................        0.41%
U.S. Population - Fall Season..............................        0.43%
U.S. Population - Winter Season............................        0.43%
Northeast Region...........................................        0.43%
North Central Region.......................................        0.43%
Western Region.............................................        0.44%
Hispanics..................................................        0.48%

[[Page 41731]]

Non-Hispanic Whites........................................        0.42%
Non-Hispanic Others........................................        0.43%
Nursing Infants (<1 year old)..............................        0.39%
Non-Nursing Infants (<1 year old)..........................        1.55%
Children (1-6 years old)...................................        1.06%
Children (7-12 years old)..................................        0.69%
Males (13-19 years old)....................................        0.46%
------------------------------------------------------------------------

    The subgroups listed above are: (1) the U.S. population (48
states); (2) those for infants and children; and, (3) the other
subgroups for which the percentage of the RfD occupied is greater than
that occupied by the subgroup U.S. population (48 states).
    2. From drinking water. In terrestrial and aquatic environments,
fluroxypyr 1-methylheptyl ester is rapidly hydrolyzed to fluroxypyr.
Fluroxypyr is further degraded (although less rapidly) by microbes to
4-amino-3,5-dichloro-6-fluoro-pyridin-2-ol ("pyridinol") and 4-amino-
3,5-dichloro-6-fluoro-2-methoxypyridine ("methoxypyridine"). In
aerobic environments, fluroxypyr, pyridinol, and methoxypyridine are
ultimately degraded to carbon dioxide.
    There are no established Maximum Contaminant Levels for residues of
fluroxypyr 1-methylheptyl ester in drinking water. No health advisory
levels for fluroxypyr 1-methylheptyl ester in drinking water have been
established.
    The assessment used SCI-GROW2 for groundwater assessment and GENEEC
Version 1.2 for acute and chronic surface water assessments. Estimated
environmental concentrations (EEC's) in surface water reflecting 0.25
lb acid equivalents/A/yr applied by air were 11.2 μg/L for
acute and 3.9 μg/L for chronic. EEC's for groundwater were
0.025 μg/L parts per billion (ppb) for acute and chronic. The
computer generated EECs represent conservative estimates and should be
used only for screening.
    i. Acute exposure and risk. OPP has calculated drinking water
levels of concern (DWLOCs) for acute exposure to fluroxypyr in drinking
water for the only relevant population subgroup, females (13+ years):
9,930 μg/L.
    To calculate the DWLOCs for acute exposure relative to an acute
toxicity endpoint, the acute dietary food exposure (from the DRES
analysis) was subtracted from the ratio of the acute NOEL (used for
acute dietary assessments) to the acceptable MOE for aggregate exposure
to obtain the acceptable acute exposure to thiafluamide in drinking
water. DWLOCs were then calculated using default body weights and
drinking water consumption figures.
    Estimated maximum concentrations of fluroxypyr in surface and
ground water are 11.2 ppb and 0.025 ppb, respectively and the DWLOC is
9,930 μg/L. The estimated maximum concentrations of fluroxypyr
in surface and ground water are less than OPP's level of concern for
fluroxypyr in drinking water as a contribution to acute aggregate
exposure.
    Therefore, taking into account present uses and uses proposed in
this action, OPP concludes with reasonable certainty that residues of
fluroxypyr 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.
    ii. Chronic exposure and risk. The "Interim Guidance for
Conducting Drinking Water Exposure and Risk Assessments" issued on 24-
NOV-1997 was followed for this assessment. Thus, the GENEEC model and
the SCI-GROW model were run to produce estimates of fluroxypyr
concentrations in surface and ground water, respectively. The primary
use of these models is to provide a coarse screen for sorting out
pesticides for which OPP has a high degree of confidence that the true
levels of the pesticide in drinking water will be less than the human
health drinking water levels of concern (DWLOCs). A DWLOC is the
concentration of a pesticide in drinking water which would be
acceptable as an upper limit in light of total aggregate exposure to
that chemical from food, water, and non-occupational (residential)
sources.
    The DWLOCchronic is the concentration in drinking water
as a part of the aggregate chronic exposure that occupies no more than
100% of the RfD. The Agency's default body weights and water
consumption values used to calculate DWLOCs are as follows: 70 kg/2L
(adult male), 60 kg/2L (adult female), and 10 kg/1L (child).
    For chronic (non-cancer) exposure to fluroxypyr in surface and
ground water, the drinking water levels of concern are 17,400
μg/L for the U.S. population, 14,900 μg/L for females
(13+ years), and 4,950 μg/L for children (1-6 yrs). To
calculate the DWLOC for chronic (non-cancer) exposure relative to a
chronic toxicity endpoint, the chronic dietary food exposure (from
DRES) was subtracted from the RfD to obtain the acceptable chronic
(non-cancer) exposure to fluroxypyr in drinking water. DWLOCs were then
calculated using default body weights and drinking consumption figures.
    Estimated average concentrations of fluroxypyr in surface and
ground water are 3.9 ppb and 0.025 ppb, respectively. The DWLOCs are
17,400 μg/L for the U.S. population, 14,900 μg/L for
females (13+ years), and 4,950 μg/L for children (1-6 yrs). The
estimated average concentrations of fluroxypyr in surface and ground
water are less than OPP's level of concern for fluroxypyr in drinking
water as a contribution to chronic aggregate exposure.
    3. From non-dietary exposure. There are no registered or proposed
residential uses for fluroxypyr 1-methylheptyl ester or fluroxypyr.
    4. Cumulative exposure to substances with 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." The Agency believes that "available
information" in this context might include not only toxicity,
chemistry, and exposure data, but also scientific policies and
methodologies for understanding common mechanisms of toxicity and
conducting cumulative risk assessments. For most pesticides, although
the Agency has some information in its files that may turn out to be
helpful in eventually determining whether a pesticide shares a common
mechanism of toxicity with any other substances, EPA does not at this
time have the methodologies to resolve the complex scientific issues
concerning common mechanism of toxicity in a meaningful way. EPA has
begun a pilot process to study this issue further through the
examination of particular classes of pesticides. The Agency hopes that
the results of this pilot process will increase the Agency's scientific
understanding of this question such that EPA will be able to develop
and apply scientific principles for better determining which chemicals
have a common mechanism of toxicity and evaluating the cumulative
effects of such chemicals. The Agency anticipates, however, that even
as its understanding of the science of common mechanisms increases,
decisions on specific classes of chemicals will be heavily dependent on
chemical specific data, much of which may not be presently available.
    Although at present the Agency does not know how to apply the
information in its files concerning common mechanism issues to most
risk assessments, there are pesticides as to which the common mechanism
issues can be resolved. These pesticides include pesticides that are
toxicologically dissimilar to existing chemical substances (in which
case the

[[Page 41732]]

Agency can conclude that it is unlikely that a pesticide shares a
common mechanism of activity with other substances) and pesticides that
produce a common toxic metabolite (in which case common mechanism of
activity will be assumed).
    EPA does not have, at this time, available data to determine
whether fluroxypyr 1-methylheptyl ester 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, fluroxypyr 1-methylheptyl ester 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 fluroxypyr 1-
methylheptyl ester has a common mechanism of toxicity with other
substances.

C. Aggregate Risks and Determination of Safety for U.S. Population

    1. Acute risk. For the population subgroup of concern, females 13+
years, the calculated Margin of Exposure (MOE) value (food) is 50,000.
The Agency acknowledges the potential for exposure to fluroxypyr 1-
methylheptyl ester in drinking water, but does not expect that exposure
would result in an aggregate MOE (food plus water) that would exceed
the Agency's level of concern for acute dietary exposure.
    2. Chronic risk. Using the TMRC exposure assumptions described
above, EPA has concluded that aggregate exposure to fluroxypyr 1-
methylheptyl ester from food will utilize 0.41% of the RfD for the U.S.
population. The major identifiable subgroup with the highest aggregate
exposure is discussed below. EPA generally has no concern for exposures
below 100% of the RfD because the RfD represents the level at or below
which daily aggregate dietary exposure over a lifetime will not pose
appreciable risks to human health. Despite the potential for exposure
to fluroxypyr 1-methylheptyl ester in drinking water and from non-
dietary, non-occupational exposure, EPA does not expect the aggregate
exposure to exceed 100% of the RfD. EPA concludes that there is a
reasonable certainty that no harm will result from aggregate exposure
to fluroxypyr 1-methylheptyl ester residues.
    3. Short- and intermediate-term risk. Short- and intermediate-term
aggregate exposure takes into account chronic dietary food and water
(considered to be a background exposure level) plus indoor and outdoor
residential exposure. There are no proposed residential uses for
fluroxypyr. Therefore, the short and intermediate aggregate risks are
adequately addressed by the chronic aggregate dietary risk assessment.

D. Aggregate Cancer Risk for U.S. Population

    Fluroxypyr has been classified as a "not likely" carcinogenic
chemical by the Agency.

E. Aggregate Risks and Determination of Safety for Infants and Children

    1. Safety factor for infants and children-- i. In general. In
assessing the potential for additional sensitivity of infants and
children to residues of fluroxypyr 1-methylheptyl ester, EPA considered
data from developmental toxicity studies in the rat and rabbit and a
two-generation reproduction study in the rat. This is generally the
case -- edit if different studies. The developmental toxicity studies
are designed to evaluate adverse effects on the developing organism
resulting from maternal pesticide exposure during gestation.
Reproduction studies provide information relating to effects from
exposure to the pesticide on the reproductive capability of mating
animals and data on systemic toxicity.
    FFDCA section 408 provides that EPA shall apply an additional 10-
fold margin of safety for infants and children in the case of threshold
effects to account for pre- and post-natal toxicity and the
completeness of the data base 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 analysis or through using
uncertainty (safety) factors in calculating a dose level that poses no
appreciable risk to humans. In either case, EPA generally defines the
level of appreciable risk as exposure that is greater than 1/100 of the
no observed effect level in the animal study appropriate to the
particular risk assessment. This 100-fold uncertainty (safety) factor/
margin of exposure (safety) is designed to account for inter-species
extrapolation and intra-species variability. HED believes that reliable
data support using the 100-fold margin/factor, rather than the 1,000-
fold margin/factor, when EPA has a complete data base under existing
guidelines, and when the severity of the effect in infants or children,
the potency or unusual toxic properties of a compound, or the quality
of the exposure data do not raise concerns regarding the adequacy of
the standard margin/factor.
    ii. Developmental toxicity studies. In the developmental study in
rats, the maternal (systemic) NOEL was 125 mg/kg/day, based on clinical
signs at the lowest observed effect level (LOEL) of 250 mg/kg/day. The
developmental (fetal) NOEL was 250 mg/kg/day, based on reduced
ossification at the LOEL of 500 mg/kg/day.
    In the developmental toxicity study in rabbits, the maternal
(systemic) NOEL was 250 mg/kg/day, based on maternal deaths at the LOEL
of 400 mg/kg/day. The developmental (pup) NOEL was 125 mg/kg/day, based
on increased postimplantation loss at the LOEL of 250 mg/kg/day.
    iii. Reproductive toxicity study. In the 2-generation reproductive
toxicity study in rats, the maternal (systemic) NOEL was 100 mg/kg/day,
based on increased kidney weights and kidney histopathology at the LOEL
of 500 mg/kg/day. The developmental (pup) NOEL was 500 mg/kg/day, based
on decreased body weight at the LOEL of 1,000 mg/kg/day. The
reproductive NOEL was 1,000 mg/kg/day HDT.
    iv. Pre- and post-natal sensitivity. The toxicological data base
for evaluating pre- and post-natal toxicity for fluroxypyr is complete
with respect to current data requirements. Based on the results of the
rabbit developmental toxicity study for fluroxypyr there does appear to
be an extra sensitivity for pre-natal effects.
    v. Conclusion. Based on the above, EPA concludes that reliable data
support use of a 300-fold margin of exposure/uncertainty factor, rather
than the standard 1000-fold margin/factor, to protect infants and
children.
    2. Acute risk. The acute dietary MOE (food) was calculated to be
6,666 for infants (<1 year), 10,000 for children (1-6 years), and
50,000 females 13+ years (accounts for both maternal and fetal
exposure). These MOE calculations were based on the developmental NOEL
in rabbits of 100 mg/kg/day. This risk assessment assumed 100% crop-
treated with tolerance level residues on all treated crops consumed,
resulting in a significant over estimation of dietary exposure. The
large acute dietary MOE calculated for females 13+ years and the
infants <1 year subgroup (lowest MOE) provides assurance that there is
a reasonable certainty of no harm for females 13+ years, infants, and
children.
    EPA acknowledges the potential for exposure to fluroxypyr 1-
methylheptyl ester in drinking water, but does not expect that exposure
would result in aggregate MOEs (food plus water) that

[[Page 41733]]

would exceed the Agency's level of concern for acute dietary exposure.
    3. Chronic risk. Using the conservative exposure assumptions
described above, EPA has concluded that aggregate exposure to
fluroxypyr 1-methylheptyl ester from food ranges from 0.39% of the RfD
for nursing infants (<1 year old) up to 1.55% of the RfD for non-
nursing infants (<1 year old). EPA generally has no concern for
exposures below 100% of the RfD because the RfD represents the level at
or below which daily aggregate dietary exposure over a lifetime will
not pose appreciable risks to human health. Despite the potential for
exposure to fluroxypyr 1-methylheptyl ester in drinking water and from
non-dietary, non-occupational exposure, EPA does not expect the
aggregate exposure to exceed 100% of the RfD. EPA concludes that there
is a reasonable certainty that no harm will result to infants and
children from aggregate exposure to fluroxypyr 1-methylheptyl ester
residues.
    4. Short- or intermediate-term risk. Short- and intermediate-term
aggregate exposure takes into account chronic dietary food and water
(considered to be a background exposure level) plus indoor and outdoor
residential uses. There are no proposed residential uses for
fluroxypyr. Therefore, the short and intermediate aggregate risks are
adequately addressed by the chronic aggregate dietary risk assessment.

V. Other Considerations

A. Metabolism In Plants and Animals

    The nature of the residue in plants and animals is adequately
understood. The residues of concern in plants and animals are
fluroxypyr 1-methylheptyl ester and its metabolite fluroxypyr, free and
conjugated, all expressed as fluroxypyr.

B. Analytical Enforcement Methodology

    Adequate enforcement methodology is available for plants (GC/MS and
capillary gas chromatography/MS) to enforce the tolerance expression.
The petitioner validated the limit of quantitation at 0.01 ppm for
cereal grains and 0.05 ppm for forage, straw, and hay of cereal grains.
    Adequate enforcement methodology is available for livestock (GC/ECD
and capillary gas chromatography with mass selective detection) to
enforce the tolerance expression. The petitioner validated the limit of
quantitation of Method GRM 96.03 at 0.01 ppm for all animal substrates.

C. Magnitude of Residues

    Residues of fluroxypyr 1-methylheptyl ester and fluroxypyr are not
expected to exceed the following levels in RAC's and processed
commodities of wheat, barley, sweet corn, field corn, and animal
commodities as a result of this section 18 use. For this section 18
only, EPA will permit the sweet corn residue data to be translated to
field corn.

------------------------------------------------------------------------
                                                              Parts per
                         Commodity                             million
------------------------------------------------------------------------
Aspirated grain fractions..................................      0.6 ppm
Corn, field, forage........................................      2.0 ppm
Corn, field, grain.........................................     0.05 ppm
Corn, field, stover........................................      2.5 ppm
Corn, sweet, forage........................................      2.0 ppm
Corn, sweet, K + CWHR......................................     0.05 ppm
Corn, sweet, stover........................................      2.5 ppm
Kidney of cattle, goats, hogs, horses, and sheep...........      0.5 ppm
Meat, fat, and meat byproducts (except kidney) of cattle,
 goats, hogs, horses, and sheep............................      0.1 ppm
Milk.......................................................      0.1 ppm
Wheat and barley, grain....................................      0.5 ppm
Wheat and barley, hay......................................     20.0 ppm
Wheat and barley, straw....................................     12.0 ppm
Wheat, forage..............................................     12.0 ppm
------------------------------------------------------------------------

D. International Residue Limits

    There are no CODEX, Canadian, or Mexican tolerances for residues of
fluoroxypyr 1-methylheptyl ester on wheat, barley, sweet corn, or field
corn.

E. Rotational Crop Restrictions

    A confined rotational crop study was conducted in which fluroxypyr
was applied at the rate of 8.8 oz ae/A. Residues in crops planted 120
days after soil treatment were 0.01 to 0.08 ppm; however, based on this
study and the section 18 use rates, residues of fluroxypyr 1-
methylheptyl ester and fluroxypyr are not expected to occur in
rotational crops at levels >0.01 ppm at the 120-day plant-back
interval. The statement "Observe a 120-day plant-back interval" is
needed on the Section 18 label, based on the confined rotational crop
study.

VI. Conclusion

    Therefore, the tolerance is established for combined residues of
fluroxypyr 1-methylheptyl ester and its metabolite fluroxypyr in wheat
and barley, grain at 0.5 ppm; wheat, forage at 12.0 ppm; wheat and
barley, hay at 20.0 ppm; wheat and barley, straw at 12.0 ppm; aspirated
grain fractions at 0.6 ppm; corn, sweet, K + CWHR at 0.05 ppm; corn,
sweet, forage at 2.0 ppm; corn, sweet, stover at 2.5 ppm; corn, field,
grain at 0.05 ppm; corn, field, forage at 2.0 ppm; corn, field, stover
at 2.5 ppm; meat, fat, and meat byproducts (except kidney) of cattle,
goats, hogs, horses, and sheep 0.1 ppm; kidney of cattle, goats, hogs,
horses, and sheep 0.5 ppm; milk 0.1 ppm.

VII. Objections and Hearing Requests

    The new FFDCA section 408(g) provides essentially the same process
for persons to "object" to a tolerance regulation issued by EPA under
new section 408(e) and (l)(6) as was provided in the old section 408
and in section 409. However, the period for filing objections is 60
days, rather than 30 days. EPA currently has procedural regulations
which govern the submission of objections and hearing requests. These
regulations will require some modification to reflect the new law.
However, until those modifications can be made, EPA will continue to
use those procedural regulations with appropriate adjustments to
reflect the new law.
    Any person may, by October 5, 1998, file written objections to any
aspect of this regulation and may also request a hearing on those
objections. Objections and hearing requests must be filed with the
Hearing Clerk, at the address given above (40 CFR 178.20). A copy of
the objections and/or hearing requests filed with the Hearing Clerk
should be submitted to the OPP docket for this rulemaking. The
objections submitted must specify the provisions of the regulation
deemed objectionable and the grounds for the objections (40 CFR
178.25). Each objection must be accompanied by the fee prescribed by 40
CFR 180.33(i). If a hearing is requested, the objections must include a
statement of the factual issues on which a hearing is requested, the
requestor's contentions on such issues, and a summary of any evidence
relied upon by the requestor (40 CFR 178.27). A request for a hearing
will be granted if the Administrator determines that the material
submitted shows the following: There is 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 in the manner sought by the requestor would be adequate
to justify the action requested (40 CFR 178.32). 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

[[Page 41734]]

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.

VIII. Public Record and Electronic Submissions

    EPA has established a record for this rulemaking under docket
control number [OPP-300688] (including any comments and data submitted
electronically). A public version of this record, including printed,
paper versions of electronic comments, which does not include any
information claimed as CBI, is available for inspection from 8:30 a.m.
to 4 p.m., Monday through Friday, excluding legal holidays. The public
record is located in Room 119 of the Public Information and Records
Integrity Branch, Information Resources and Services Division (7502C),
Office of Pesticide Programs, Environmental Protection Agency, Crystal
Mall #2, 1921 Jefferson Davis Highway, Arlington, VA.
    Electronic comments may be sent directly to EPA at:
    opp-docket@epamail.epa.gov.

    Electronic comments must be submitted as an ASCII file avoiding the
use of special characters and any form of encryption.
    The official record for this rulemaking, as well as the public
version, as described above will be kept in paper form. Accordingly,
EPA will transfer any copies of objections and hearing requests
received electronically into printed, paper form as they are received
and will place the paper copies in the official rulemaking record which
will also include all comments submitted directly in writing. The
official rulemaking record is the paper record maintained at the
Virginia address in "ADDRESSES" at the beginning of this document.

IX. Regulatory Assessment Requirements

    This final rule establishes tolerances under FFDCA section
408(l)(6). 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) (Pub. L. 104-4). Nor does it require any prior consultation as
specified by Executive Order 12875, entitled Enhancing the
Intergovernmental Partnership (58 FR 58093, October 28, 1993), or
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 in accordance with Executive Order 13045,
entitled Protection of Children from Environmental Health Risks and
Safety Risks (62 FR 19885, April 23, 1997).
    In addition, since these tolerances and exemptions that are
established under FFDCA section 408 (l)(6), such as the tolerances 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. Nevertheless, the Agency has previously assessed
whether establishing tolerances, exemptions from tolerances, raising
tolerance levels or expanding exemptions might adversely impact small
entities and concluded, as a generic matter, that there is no adverse
economic impact. The factual basis for the Agency's generic
certification for tolerance acations published on May 4, 1981 (46 FR
24950), and was provided to the Chief Counsel for Advocacy of the Small
Business Administration.

X. 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 the rule in the Federal Register. This 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: July 16, 1998.

James Jones,

Director, Registration Division, 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. 346a and 371.

    2. Section 180.535 is added to read as follows:

Sec. 180.535   Fluroxypyr 1-methylheptyl ester; tolerances for
residues.

    (a) General. [Reserved]
    (b) Section 18 emergency exemptions. Time-limited tolerances are
established for the combined residues of fluroxypyr 1-methylheptyl
ester and its metabolite fluroxypyr, in connection with use of the
pesticide under section 18 emergency exemptions granted by EPA. The
tolerances will expire and are revoked on the dates specified in the
following table.

------------------------------------------------------------------------
                                                  Parts
                   Commodity                       per      Expiration/
                                                 million  RevocationDate
------------------------------------------------------------------------
Aspirated grain fractions......................      0.6        12/1/99
Barley, grain..................................      0.5        12/1/99
Barley, hay....................................     20.0        12/1/99
Barley, straw..................................     12.0        12/1/99
Cattle, fat....................................      0.1        12/1/99
Cattle, kidney.................................      0.5        12/1/99
Cattle, mbyp...................................      0.1        12/1/99
Cattle meat....................................      0.1        12/1/99
Corn, field, forage............................      2.0        12/1/99
Corn, field, grain.............................     0.05        12/1/99
Corn, field, stover............................      2.5        12/1/99
Corn, sweet, forage............................      2.0        12/1/99
Corn, sweet, K + CWHR..........................     0.05        12/1/99
Corn, sweet, stover............................      2.5        12/1/99
Goats, fat.....................................      0.1        12/1/99
Goats, kidney..................................      0.5        12/1/99
Goats, mbyp....................................      0.1        12/1/99
Goats, meat....................................      0.1        12/1/99
Hogs, fat......................................      0.1        12/1/99
Hogs, kidney...................................      0.5        12/1/99
Hogs, mbyp.....................................      0.1        12/1/99
Hogs, meat.....................................      0.1        12/1/99
Horses, fat....................................      0.1        12/1/99
Horses, kidney.................................      0.5        12/1/99
Horses, mbyp...................................      0.1        12/1/99
Horses, meat...................................      0.1        12/1/99
Milk...........................................      0.1        12/1/99
Sheep, fat.....................................      0.1        12/1/99
Sheep, kidney..................................      0.5        12/1/99
Sheep, mbyp....................................      0.1        12/1/99
Sheep meat.....................................      0.1        12/1/99
Wheat, forage..................................     12.0        12/1/99
Wheat, grain...................................      0.5        12/1/99
Wheat, hay.....................................     20.0        12/1/99

[[Page 41735]]

Wheat, straw...................................     12.0        12/1/99
------------------------------------------------------------------------

    (c) Tolerances with regional registrations. [Reserved]
    (d) Indirect or inadvertent residues. [Reserved]

[FR Doc. 98-20905 Filed 8-4-98; 8:45 am]
BILLING CODE 6560-50-F