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diflufenzopyr Pesticide Tolerance 8/02


ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-2002-0220; FRL-7195-8]

Diflufenzopyr; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes tolerances for combined residues
of diflufenzopyr in or on corn, sweet, forage; corn, sweet, kernel plus
cob with husks removed; and corn, sweet, stover at 0.05 part per
million (ppm); corn, pop, grain and corn, pop, stover at 0.05 ppm;
grass, forage at 22 ppm; and grass, hay at 7.0 ppm. This regulation
also establishes time-limited tolerances for combined residues of
diflufenzopyr in or on cattle, goat, hog, horse, and sheep meat at 0.60
ppm; cattle, goat, hog, horse, and sheep kidney at 4.0 ppm; cattle,
goat, hog, horse, and sheep meat byproducts, except kidney at 0.50 ppm;
cattle, goat, hog, horse, and sheep fat at 0.30 ppm; and milk at 3.0
ppm. The Interregional Research Project Number 4 (IR-4) requested these
tolerances under the Federal Food, Drug, and Cosmetic Act (FFDCA), as
amended by the Food Quality Protection Act (FQPA) of 1996.

DATES: This regulation is effective August 29, 2002. Objections and
requests for hearings, identified by docket ID number OPP-2002-0220,
must be received on or before October 28, 2002.

ADDRESSES: Written objections and hearing requests may be submitted by
mail, in person, or by courier. Please follow the detailed instructions
for each method as provided in Unit VI. of the SUPPLEMENTARY
INFORMATION. To ensure proper receipt by EPA, your objections and
hearing requests must identify docket ID number OPP-2002-0220 in the
subject line on the first page of your response.

FOR FURTHER INFORMATION CONTACT: By mail: Shaja R. Brothers,
Registration Division (7505C), Office of Pesticide Programs,
Environmental Protection Agency, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460; telephone number: (703) 308-3194; e-mail address:
brothers.shaja@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 codes         potentially
                                                       affected entities
------------------------------------------------------------------------
Industry                          111                 Crop production
                                  112                 Animal production
                                  311                 Food manufacturing
                                  32532               Pesticide
                                                       manufacturing
------------------------------------------------------------------------

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

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

    1. Electronically. You may obtain electronic copies of this
document, and certain other related documents that might be available
electronically, from the EPA Internet Home Page at http://www.epa.gov/.
To access this document, on the Home Page select "Laws and
Regulations," "Regulations and Proposed Rules," and then look up the
entry for this document under the "Federal Register--Environmental
Documents." You can also go directly to the Federal Register listings
at http://www.epa.gov/fedrgstr/. A frequently updated electronic
version of 40 CFR part 180 is available at http://www.access.gpo.gov/
nara/cfr/cfrhtml--00/Title--40/40cfr180--00.html, a beta site currently
under development. To access the OPPTS Harmonized Guidelines referenced
in this document, go directly to the guidelines at http://www.epa.gov/opptsfrs/home/guidelin.htm.
    2. In person. The Agency has established an official record for
this action under docket ID number OPP-2002-0220. The official record
consists of the documents specifically referenced in this action, and
other information related to this action, including any information
claimed as Confidential Business Information (CBI). This official
record includes the documents that are physically located in the
docket, as well as the documents that are referenced in those
documents. The public version of the official record does not include
any information claimed as CBI. The public version of the official
record, which includes printed, paper versions of any electronic
comments submitted during an applicable comment period is available for
inspection in the Public Information and Records Integrity Branch
(PIRIB), Rm. 119, Crystal Mall ι2, 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 December 12, 2001 (66 FR 64257) (FRL-
6812-7), and June 12, 2002 (67 FR 40292) (FRL-7181-2), EPA issued
notices pursuant to section 408 of the FFDCA, 21 U.S.C. 346a, as
amended by the FQPA of 1996 (Public Law 104-170), announcing the filing
of a pesticide petition (PP 0E6185) by IR-4, 681 U.S. Highway
ι1 South, North Brunswick, NJ 08902-3390. These notices
included a summary of the petition prepared by BASF Corporation, the
registrant. There were no comments received in response to the notices
of filing.
    The petition requested that 40 CFR 180.549 be amended by
establishing tolerances for the combined residues of the herbicide
diflufenzopyr in or on corn, sweet, forage; corn, sweet, kernel plus
cob with husks removed; and corn, sweet, stover at 0.05 ppm; corn, pop,
grain, and corn, pop, stover at 0.05 ppm; grass, forage at 22 ppm; and
grass, hay at 7.0 ppm. The petition was subsequently revised to request
that 40 CFR 180.549 be amended by establishing time-limited tolerances
for residues of the herbicide diflufenzopyr, 2-(1-(3,5-
difluorophenylamino) carbonyl)hydrazono)ethyl)(-3-pyridinecarboxylic
acid, its metabolites convertible to 8-methylpyrido[2,3-d]pyridazin-
5(6H)-one, and free and acid-released 8-hydroxymethylpyrido[2,3-d]
pyridazine-2,5(1H,6H)-dione, expressed as diflufenzopyr, in or on
cattle, goat, hog, horse, and sheep meat at 0.60 ppm; cattle, goat,
hog, horse, and sheep kidney at 4.0 ppm; cattle, goat, hog, horse, and
sheep meat byproducts, except kidney at 0.50 ppm; cattle, goat, hog,
horse, and sheep fat at 0.30 ppm; and milk at 3.0 ppm.
    Section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a
tolerance (the legal limit for a pesticide chemical residue in or on a
food) only if EPA determines that the tolerance is "safe." Section
408(b)(2)(A)(ii) defines "safe" to mean that "there is a reasonable
certainty that no harm will result from aggregate exposure to the
pesticide chemical residue, including all anticipated dietary exposures
and all other exposures for which there is reliable information." This
includes exposure through drinking water and in residential settings,
but does not include occupational exposure. Section 408(b)(2)(C)
requires EPA to give special consideration to exposure of infants and
children to the pesticide chemical residue in establishing a tolerance
and to "ensure that there is a reasonable certainty that no harm will
result to infants and children from aggregate exposure to the pesticide
chemical residue. . . ."
    EPA performs a number of analyses to determine the risks from
aggregate exposure to pesticide residues. For further discussion of the
regulatory requirements of section 408 and a complete description of
the risk assessment process, see the final rule on Bifenthrin Pesticide
Tolerances November 26, 1997 (62 FR 62961) (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
these actions. EPA has sufficient data to assess the hazards of and to
make a determination on aggregate exposure, consistent with section
408(b)(2), for tolerances for the combined residues of diflufenzopyr on
corn, sweet, forage; corn, sweet, kernel plus cob with husks removed;
corn, sweet, stover at 0.05 ppm; corn, pop, grain; and corn, pop,
stover at 0.05 ppm; grass, forage at 22 ppm; grass, hay at 7.0 ppm;
cattle, goat, hog, horse, and sheep fat at 0.30 ppm; cattle, goat, hog,
horse, and sheep kidney at 4.0 ppm; cattle, goat, hog, horse, and sheep
meat byproducts, except kidney at 0.50 ppm; cattle, goat, hog, horse,
and sheep meat at 0.60 ppm;, and milk at 3.0 ppm. EPA's assessment of
exposures and risks associated with establishing tolerances follow.

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 diflufenzopyr is
discussed in Unit III.A. of the Final Rule on Diflufenzopyr Pesticide
Tolerance published in the Federal Register of January 28, 1999 (64 FR
4301) (FRL-6053-8).

B. Toxicological Endpoints

    The dose at which no adverse effects are observed (the NOAEL) from
the toxicology study identified as appropriate for use in risk
assessment is used to estimate the toxicological level of concern
(LOC). However, the lowest dose at which adverse effects of concern
are identified (the LOAEL) is sometimes used for risk assessment if no
NOAEL was achieved in the toxicology study selected. An uncertainty
factor (UF) is applied to reflect uncertainties inherent in the
extrapolation from laboratory animal data to humans and in the
variations in sensitivity among members of the human population as well
as other unknowns. An UF of 100 is routinely used, 10X to account for
interspecies differences and 10X for 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 10-6 or one in a million).
Under certain specific circumstances, MOE calculations will be used for
the carcinogenic risk assessment. In this non-linear approach, a
"point of departure" is identified below which carcinogenic effects
are not expected. The point of departure is typically a NOAEL based on
an endpoint related to cancer effects though it may be a different
value derived from the dose response curve. To estimate risk, a ratio
of the point of departure to exposure (MOE-cancer = point of
departure/exposures) is calculated. A summary of the toxicological
endpoints for diflufenzopyr used for human risk assessment is shown in
the following Table 1:
Table 1.--Summary of Toxicological Dose and Endpoints for diflufenzopyr for Use in Human Risk Assessment
Exposure Scenario
Dose Used in Risk Assessment,
UF
FQPA SF* and Level of
Concern for Risk Assessment
Study and Toxicological Effects
Acute dietary (females 13–50 years of age) NOAEL = 100 milligrams/
kilogram/day
(mg/kg/day)
UF = 100
Acute RfD = 1.0 mg/kg/
day
FQPA SF = 1X
aPAD = acute RfD
FQPA SF = 1.0 mg/kg/
day
Rabbit Developmental
LOAEL = 300 mg/kg/day based on extra ribs and other skeletal variations in the rabbit developmental study. These effects can occur from a single dose and
females 13–50 are the population subgroup of concern. The developmental findings occurred at a level of severe maternal toxicity.
Acute dietary (general population
including infants
and children)
None None An appropriate endpoint attributable to a single exposure for this population subgroup was not identified in the oral toxicity studies including the maternal effects in rat and rabbit developmental
studies.
Chronic dietary (all populations) NOAEL = 26 mg/kg/day
UF = 100
Chronic RfD = 0.26 mg/
kg/day
FQPA SF = 1X
cPAD = chronic RfD
FQPA SF = 0.26 mg/kg/
day
52–Week feeding study in dogs
LOAEL = 299 mg/kg/day based on compensated
hemolytic anemia in both
sexes of dogs
Short-term, and intermediate-
term dermal (Residential)
None None No dermal or systemic toxicity was seen
at 1,000 mg/kg/day in the 21–day dermal
toxicity study in rabbits. Therefore,
these risk assessments were not performed.
Long-term dermal
(Residential)
None None The use pattern does not indicate a concern
for potential residential dermal exposure.
Therefore, this risk assessment
was not performed.
Short-intermediate, and
long-term inhalation
(Residential)
None None The use pattern does not indicate a concern
for potential residential inhalation exposure. Therefore, this risk assessment was not performed.
Cancer (oral, dermal, inhalation) None None In accordance with the 1996 Proposed
Guidelines for Carcinogenicity Risk Assessments,
diflufenzopyr was classified as "Not Likely" to be a human carcinogen. This classification is based on the lack of evidence of carcinogenicity in mice and rats when tested at doses that were judged to be adequate to assess
carcinogenicity.
* The reference to the FQPA Safety Factor refers to any additional safety factor retained due to concerns unique to the FQPA.
C. Exposure Assessment

    1. Dietary exposure from food and feed uses. Tolerances have been
established (40 CFR 180.549) for the combined residues of
diflufenzopyr, in or on a variety of raw agricultural commodities.
Time-limited tolerances are currently being established for cattle,
goat, hog, horse, and sheep meat, kidney, liver, fat, and milk. Risk
assessments were conducted by EPA to assess dietary exposures from
diflufenzopyr 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 1-day or
single exposure. The Dietary Exposure Evaluation Model
(DEEMTM) analysis evaluated the individual food consumption
as reported by respondents in the U.S. Department of Agriculture (USDA)
1989-1992 nationwide Continuing Surveys of Food Intake by Individuals
(CSFII) and accumulated exposure to the chemical for each commodity.
The following assumptions were made for the acute exposure assessments:
An appropriate endpoint attributable to a single exposure for the
general U.S. population (including infants and children) population
subgroup was not identified in the oral toxicity studies including the
maternal effects in rat and rabbit developmental studies. However, a
Tier 1 acute dietary exposure assessment was performed for females 13-
50 years old using recommended tolerance level residues (livestock) and
total residues of concern (plants; parent and metabolites). Default
DEEMTM concentration factors and 100% crop treated
information were used for all commodities.
    ii. Chronic exposure. In conducting this chronic dietary risk
assessment, the DEEMTM analysis evaluated the individual
food consumption as reported by respondents in the USDA 1989-1992
nationwide CSFII and accumulated exposure to the chemical for each
commodity. The following assumptions were made for the chronic exposure
assessments: The chronic dietary exposure analysis was performed for
the general U.S. population and all population subgroups using
recommended tolerance level residues (livestock) and total residues of
concern (plants; parent and metabolites). Default DEEMTM
concentration factors and 100% crop treated information were used for
all commodities.
    iii. Cancer. In accordance with the 1996 Proposed Guidelines for
Carcinogenicity Risk Assessments, diflufenzopyr was classified as "not
likely" to be a human carcinogen, therefore, a cancer exposure
assessment was not performed.
    2. Dietary exposure from drinking water. The Agency lacks
sufficient monitoring exposure data to complete a comprehensive dietary
exposure analysis and risk assessment for diflufenzopyr 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 diflufenzopyr.
    The Agency uses the Generic Estimated Environmental Concentration
(GENEEC) or the Pesticide Root Zone Model/Exposure Analysis Modeling
System (PRZM/EXAMS) to estimate pesticide concentrations in surface
water and SCI-GROW, which predicts pesticide concentrations in ground
water. 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, while PRZM/EXAMS incorporate an
index reservoir environment in place of the previous pond scenario. The
PRZM/EXAMS model includes a percent crop area factor as an adjustment
to account for the maximum percent crop coverage within a watershed or
drainage basin.
    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 screen for sorting out pesticides for which it is
highly unlikely that drinking water concentrations would 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 diflufenzopyr, they are further
discussed in the aggregate risk sections in Unit III.E. Diflufenzopyr
is not very stable and mobile. Based upon proposed uses, fate
characteristics, and model predictions, the Agency does not expect
diflufenzopyr to reach drinking water resources in significant
quantities.
    Based on the GENEEC and SCI-GROW models, the EECs of diflufenzopyr
for acute exposures are estimated to be 3.80 parts per billion (ppb) for
surface water and 0.006 ppb for ground water. The EECs for chronic
exposures are estimated to be 0.65 ppb for surface water and 0.006 ppb
for ground 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). Diflufenzopyr is not
registered for use on any sites that would result in residential
exposure, therefore, a residential exposure assessment was not
performed.
    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 diflufenzopyr 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,
diflufenzopyr 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 diflufenzopyr 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. 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 using uncertainty (safety) factors in
calculating a dose level that poses no appreciable risk to humans.
    2. Prenatal and postnatal sensitivity. Developmental NOAEL and the
lowest observed adverse effect level (LOAEL) for both rats and rabbits
occurred at either the same dose levels or were above the NOAELs and
LOAELs for maternal toxicity. The NOAEL for pup effects in the 2-
generation rat reproduction study occurred at dose levels above the
NOAEL for parental findings. Based on these data, EPA determined that
there was no evidence of increased sensitivity for infants and
children.
    3. Conclusion. There is a complete toxicity data base for
diflufenzopyr and exposure data are complete or are estimated based on
data that reasonably accounts for potential exposures. EPA determined
that the 10X safety factor to protect infants and children should be
reduced to 1X. The FQPA safety factor is reduced because: (1) The
toxicology data base is complete; (2) there is no indication of
increased susceptibility of rats and rabbits fetuses to in utero, and/
or postnatal exposure in the developmental and reproductive toxicity
data; (3) unrefined (tier 1) dietary exposure estimates used in the
risk assessment are protective since they will exaggerate dietary
exposure estimates; (4) modeling data are used for ground and surface
source drinking water exposure assessments resulting in estimates
considered to be upper-bound concentrations; and (5) there are
currently no registered residential uses for diflufenzopyr.

E. Aggregate Risks and Determination of Safety

    To estimate total aggregate exposure to a pesticide from food,
drinking water, and residential uses, the Agency calculates DWLOCs
which are used as a point of comparison against the model estimates of
a pesticide's concentration in water (EECs). DWLOC values are not
regulatory standards for drinking water. DWLOCs are theoretical upper
limits on a pesticide's concentration in drinking water in light of
total aggregate exposure to a pesticide in food and residential uses.
In calculating a DWLOC, the Agency determines how much of the
acceptable exposure (i.e., the PAD) is available for exposure through
drinking water (e.g., allowable chronic water 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 EPA 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 ground water are less than the
calculated DWLOCs, EPA concludes with reasonable certainty that
exposures to the pesticide in drinking water (when considered along
with other sources of exposure for which EPA has reliable data) would
not result in unacceptable levels of aggregate human health risk at
this time. Because EPA 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, EPA will reassess the potential impacts
of residues of the pesticide in drinking water as a part of the
aggregate risk assessment process.
    1. Acute risk. An appropriate endpoint attributable to a single
exposure for the general U.S. population (including infants and
children) population subgroup was not identified. Therefore, the data
do not indicate any adverse effect to the U.S. population subgroup as a
result of acute dietary exposure. The acute dietary exposure assessment
was performed for females 13-50 years old using tolerance level
residues (livestock) and total residues of concern (plants; parent and
metabolites). Using the exposure assumptions discussed in this unit for
acute exposure, the acute dietary exposure from food to diflufenzopyr
will occupy 4% of the aPAD for females 13 years and older. In addition,
there is potential for acute dietary exposure to diflufenzopyr in
drinking water. After calculating DWLOCs and comparing them to the EECs
for surface and ground water, EPA does not expect the aggregate
exposure to exceed 100% of the aPAD, as shown in the following Table 2:
Table 2.--Aggregate Risk Assessment for Acute Exposure to diflufenzopyr
Population Subgroup
aPAD (mg/
kg)
%aPAD
(Food)
Surface
Water EEC
(ppb)
Ground
Water EEC
(ppb)
Acute
DWLOC
(ppb)
Females (13–50 years old) 1.0 4 3.80 0.006 29,000
    2. Chronic risk. Using the exposure assumptions described in this
unit for chronic exposure, EPA has concluded that exposure to
diflufenzopyr from food will utilize 9% of the cPAD for the U.S.
population and all population subgroups. The most highly exposed
population subgroup was children 1-6 years old utilizing 32% of the
cPAD. There are no residential uses for diflufenzopyr that result in
chronic residential exposure to diflufenzopyr. In addition, there is
potential for chronic dietary exposure to diflufenzopyr in drinking
water. After calculating DWLOCs and comparing them to the EECs for
surface water and ground water, EPA does not expect the aggregate
exposure to exceed 100% of the cPAD, as shown in the following Table 3:
Table 3.--Aggregate Risk Assessment for Chronic (Non-Cancer) Exposure to diflufenzopyr
Population Subgroup
cPAD (mg/
kg)
%cPAD
(Food)
Surface
Water EEC
(ppb)
Ground
Water EEC
(ppb)
Chronic
DWLOC
(ppb)
U.S. population 0.26 9 0.65 0.006 8,300
Females (13–50 years old) 0.26 5 0.65 0.006 7,400
Children (1–6 years old) 0.26 32 0.65 0.006 1,800
All infants (less than 1–year) 0.26 14 0.65 0.006 2,200
    3. Short-term and intermediate-term risk. Short-term and
intermediate-term aggregate exposures take into account residential
exposure plus chronic exposure to food and water (considered to be a
background exposure level). Short-term and intermediate-term aggregate
risk assessments were not performed since there are no registered or
proposed residential uses for diflufenzopyr. Therefore, short-term and
intermediate-term exposure is not expected.
    4. Aggregate cancer risk for U.S. population. In accordance with
the 1996 Proposed Guidelines for Carcinogenicity Risk Assessments,
diflufenzopyr was classified as "not likely" to be a human
carcinogen. This classification is based on the lack of evidence of
carcinogenicity in mice and rats when tested at doses that were judged
to be adequate to assess carcinogenicity. The Agency concludes that
pesticidal uses of diflufenzopyr are not likely to pose a carcinogenic
risk to humans.
    5. Determination of safety. Based on these risk assessments, EPA
concludes that there is a reasonable certainty that no harm will result
to the general population, and to infants and children from aggregate
exposure to diflufenzopyr residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    1. Plants. An adequate enforcement method is available for
enforcement of the proposed tolerances for sweet corn and pop corn. The
Agency has conducted a successful petition method validation (PMV) of
method, and will be forwarded to the Food and Drug Administration (FDA)
for inclusion in Pesticide Analytical Method Volume (PAM) Vol. II. The
method may be requested from: Francis Griffith, Analytical Chemistry
Branch, Environmental Science Center, Environmental Protection Agency,
701 Mapes Road, Fort George G. Mead, MD 20755-5350; telephone number:
(410) 305-20905; e-mail address: griffith.francis@epa.gov.
    2. Livestock. BASF Corporation has submitted an analytical method
for livestock commodities, which has undergone independent laboratory
validation.

B. International Residue Limits

    There are currently no established Codex, Mexican maximum residue
limits (MRLs) for residues of diflufenzopyr in/on plant or livestock
commodities. A Canadian MRL of 0.05 ppm for residues of diflufenzopyr,
expressed as the parent and metabolites convertible to M1, has been
established for corn. No compatibility issues exist with regard to the
existing and proposed U.S. tolerances.

C. Conditions

    The registrant submitted a meat and milk magnitude of residue study
in lactating dairy cows. Registration for use of diflufenzopyr on sweet
corn, pop corn, forage, and hay grasses will be conditional pending the
outcome of the Agency's review of the submitted study.

V. Conclusion

    Therefore, the tolerances are established for combined residues of
diflufenzopyr, 2-(1-[([3,5-difluorophenylamino]
carbonyl)hydrazono]ethyl)-3-pyridinecarboxylic acid, and its
metabolites convertible to 8-methylpyrido[2,3-d]pyridazin-5(6H)-one,
expressed as diflufenzopyr, in or on corn, sweet, forage; corn, sweet,
kernel plus cob with husks removed; and corn, sweet, stover at 0.05
ppm; corn, pop, grain, and corn, pop, stover at 0.05 ppm; forage, grass
at 22 ppm; and forage, hay at 7.0 ppm.
    Time-limited tolerances are also established for combined residues
of diflufenzopyr, 2-(1-[([3,5-difluorophenylamino]
carbonyl)hydrazono]ethyl)-3-pyridinecarboxylic acid, its metabolites
convertible to 8-methylpyrido[2,3-d]pyridazin-5(6H)-one, and free and
acid-released 8-hydroxymethylpyrido[2,3-d]pyridazine-
2,5(1H,6H)-dione, expressed as diflufenzopyr, in or on cattle, goat,
hog, horse, and sheep meat at 0.60 ppm; cattle, goat, hog, horse, and
sheep kidney at 4.0 ppm; cattle, goat, hog, horse, and sheep meat
byproducts, except kidney at 0.50 ppm; cattle, goat, hog, horse, and
sheep fat at 0.30 ppm; and milk at 3.0 ppm.

VI. Objections and Hearing Requests

    Under section 408(g) of the FFDCA, as amended by the FQPA, any
person may file an objection to any aspect of this regulation and may
also request a hearing on those objections. The EPA procedural
regulations which govern the submission of objections and requests for
hearings appear in 40 CFR part 178. Although the procedures in those
regulations require some modification to reflect the amendments made to
the FFDCA by the FQPA of 1996, EPA will continue to use those
procedures, with appropriate adjustments, until the necessary
modifications can be made. The new section 408(g) provides essentially
the same process for persons to "object" to a regulation for an
exemption from the requirement of a tolerance issued by EPA under new
section 408(d), as was provided in the old FFDCA sections 408 and 409.
However, the period for filing objections is now 60 days, rather than
30 days.

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

    You must file your objection or request a hearing on this
regulation in accordance with the instructions provided in this unit
and in 40 CFR part 178. To ensure proper receipt by EPA, you must
identify docket ID number OPP-2002-0220 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 October
28, 2002.
    1. Filing the request. Your objection must specify the specific
provisions in the regulation that you object to, and the grounds for
the objections (40 CFR 178.25). If a hearing is requested, the
objections must include a statement of the factual issues(s) on which a
hearing is requested, the requestor's contentions on such issues, and a
summary of any evidence relied upon by the objector (40 CFR 178.27).
Information submitted in connection with an objection or hearing
request may be claimed confidential by marking any part or all of that
information as CBI. Information so marked will not be disclosed except
in accordance with procedures set forth in 40 CFR part 2. A copy of the
information that does not contain CBI must be submitted for inclusion
in the public record. Information not marked confidential may be
disclosed publicly by EPA without prior notice.
    Mail your written request to: Office of the Hearing Clerk (1900C),
Environmental Protection Agency, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460. You may also deliver your written request to the
Office of the Hearing Clerk in Rm. 104, Crystal Mall ι 2, 1921
Jefferson Davis Hwy., Arlington, VA. 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
(703) 603-0061.
    2. Tolerance fee payment. If you file an objection or request a
hearing, you must also pay the fee prescribed by 40 CFR 180.33(i) or
request a waiver of that fee pursuant to 40 CFR 180.33(m). You must
mail the fee to: EPA Headquarters Accounting Operations Branch, Office
of Pesticide Programs, P.O. Box 360277M, Pittsburgh, PA 15251. Please
identify the fee submission by labeling it "Tolerance Petition Fees."
    EPA is authorized to waive any fee requirement "when in the
judgement of the Administrator such a waiver or refund is equitable and
not contrary to the purpose of this subsection." For additional
information regarding the waiver of these fees, you 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.
    3. Copies for the Docket. In addition to filing an objection or
hearing request with The Hearing Clerk as described in Unit VI.A., you
should also send a copy of your request to the PIRIB for its inclusion
in the official record that is described in Unit I.B.2. Mail your
copies, identified by docket ID number OPP-2002-0220, 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 or ASCII file format.
Do not include any CBI in your electronic copy. You may also submit an
electronic copy of your request at many Federal Depository Libraries.

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

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

VII. Regulatory Assessment Requirements

    This final rule establishes a tolerance under FFDCA section 408(d)
in response to a petition submitted to the Agency. The Office of
Management and Budget (OMB) has exempted these types of actions from
review under Executive Order 12866, entitled Regulatory Planning and
Review (58 FR 51735, October 4, 1993). Because this rule has been
exempted from review under Executive Order 12866 due to its lack of
significance, this rule is not subject to Executive Order 13211,
Actions Concerning Regulations That Significantly Affect Energy Supply,
Distribution, or Use (66 FR 28355, May 22, 2001). This final rule does
not contain any information collections subject to OMB approval under
the Paperwork Reduction Act (PRA), 44 U.S.C. 3501 et seq., or impose
any enforceable duty or contain any unfunded mandate as described under
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA) (Public Law
104-4). Nor does it require any special considerations under Executive
Order 12898, entitled Federal Actions to Address Environmental Justice
in Minority Populations and Low-Income Populations (59 FR 7629,
February 16, 1994); or OMB review or any Agency action under Executive
Order 13045, entitled Protection of Children from Environmental Health
Risks and Safety Risks (62 FR 19885, April 23, 1997). This action does
not involve any technical standards that would require Agency consideration
of voluntary consensus standards pursuant to section 12(d) of the National
Technology Transfer and Advancement Act of 1995 (NTTAA), Public Law
104-113, section 12(d) (15 U.S.C. 272 note). Since tolerances and
exemptions that are established on the basis of a petition under FFDCA
section 408(d), such as the tolerance in this final rule, do not
require the issuance of a proposed rule, the requirements of the
Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et seq.) do not apply.
In addition, the Agency has determined that this action will not have a
substantial direct effect on States, on the relationship between the
national government and the States, or on the distribution of power and
responsibilities among the various levels of government, as specified
in Executive Order 13132, entitled Federalism (64 FR 43255, August 10,
1999). Executive Order 13132 requires EPA to develop an accountable
process to ensure "meaningful and timely input by State and local
officials in the development of regulatory policies that have
federalism implications." "Policies that have federalism
implications" is defined in the Executive Order to include regulations
that have "substantial direct effects on the States, on the
relationship between the national government and the States, or on the
distribution of power and responsibilities among the various levels of
government." This final rule directly regulates growers, food
processors, food handlers and food retailers, not States. This action
does not alter the relationships or distribution of power and
responsibilities established by Congress in the preemption provisions
of FFDCA section 408(n)(4). For these same reasons, the Agency has
determined that this rule does not have any "tribal implications" as
described in Executive Order 13175, entitled Consultation and
Coordination with Indian Tribal Governments (65 FR 67249, November 6,
2000). Executive Order 13175, requires EPA to develop an accountable
process to ensure "meaningful and timely input by tribal officials in
the development of regulatory policies that have tribal implications."
"Policies that have tribal implications" is defined in the Executive
Order to include regulations that have "substantial direct effects on
one or more Indian tribes, on the relationship between the Federal
Government and the Indian tribes, or on the distribution of power and
responsibilities between the Federal Government and Indian tribes."
This rule will not have substantial direct effects on tribal
governments, on the relationship between the Federal Government and
Indian tribes, or on the distribution of power and responsibilities
between the Federal Government and Indian tribes, as specified in
Executive Order 13175. Thus, Executive Order 13175 does not apply to
this rule.

VIII. Submission to Congress and the Comptroller General

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. EPA will submit a report containing this rule and other
required information to the U.S. Senate, the U.S. House of
Representatives, and the Comptroller General of the United States prior
to publication of this final rule in the Federal Register. This final
rule is not a "major rule" as defined by 5 U.S.C. 804(2).

List of Subjects in 40 CFR Part 180

    Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and
recordkeeping requirements.

    Dated: August 20, 2002.
Debra Edwards,
Acting 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. 321(q), 346(a) and 374.

    2. Section 180.549 is amended by revising paragraph (a) to read as
follows:

Sec. 180.549  Diflufenzopyr, tolerances for residues.

    (a) General. Tolerances are established for combined residues of
diflufenzopyr, 2-(1-[([3,5-difluorophenylamino]carbonyl)
hydrazono]ethyl)-3-pyridinecarboxylic acid, and its metabolites
convertible to 8-methylpyrido[2,3-d]pyridazin-5(6H)-one, expressed as
diflufenzopyr, in or on the following raw agricultural commodities:

----------------------------------------------------------------------------------------------------------------
                       Commodity Parts per million
----------------------------------------------------------------------------------------------------------------
Corn, field, forage................................... 0.05
Corn, field, grain.................................... 0.05
Corn, field, stover................................... 0.05
Corn, pop, grain...................................... 0.05
Corn, pop, stover..................................... 0.05
Corn, sweet, forage................................... 0.05
Corn, sweet, kernel plus cob with husks removed....... 0.05
Corn, sweet, stover................................... 0.05
Grass, forage......................................... 22.0
Grass, hay............................................ 7.0
----------------------------------------------------------------------------------------------------------------

    (2) Time-limited tolerances are established for combined residues
of diflufenzopyr, 2-(1-[([3,5-difluorophenylamino]carbonyl)
hydrazono]ethyl)-3- pyridinecarboxylic acid, its metabolites
convertible to 8-methylpyrido[2,3-d]pyridazin- 5(6H)-one, and free and
acid-released 8-hydroxymethylpyrido[2,3-d]pyridazine-2,5(1H,6H)-dione,
expressed as diflufenzopyr, in or on the following raw agricultural
commodities:

----------------------------------------------------------------------------------------------------------------
                Commodity                          Parts per million Expiration/Revocation Date
----------------------------------------------------------------------------------------------------------------
Cattle, fat............................. 0.30                             7/31/05
Cattle, kidney.......................... 4.0                             7/31/05
Cattle, meat............................ 0.60                             7/31/05
Cattle, meat byproducts, except kidney..            0.50 7/31/05
Goat, fat............................... 0.30                             7/31/05
Goat, kidney............................ 4.0                             7/31/05
Goat, meat.............................. 0.60                             7/31/05
Goat, meat byproducts, except kidney....            0.50 7/31/05
Hog, fat................................ 0.30                             7/31/05
Hog, kidney............................. 4.0                             7/31/05
Hog, meat............................... 0.60                             7/31/05
Hog, meat byproducts, except kidney.....             0.50 7/31/05
Horse, fat.............................. 0.30                             7/31/05
Horse, kidney........................... 4.0                             7/31/05
Horse, meat............................. 0.60                             7/31/05
Horse, meat byproducts, except kidney...             0.50 7/31/05
Milk.................................... 3.0                             7/31/05
Sheep, fat.............................. 0.30                             7/31/05
Sheep, kidney........................... 4.0                             7/31/05
Sheep, meat............................. 0.60                             7/31/05
Sheep, meat byproducts, except kidney...             0.50 7/31/05
----------------------------------------------------------------------------------------------------------------

* * * * *
[FR Doc. 02-22092 Filed 8-28-02; 8:45 a.m.]
BILLING CODE 6560-50-S