Diflubenzuron (IR-4; Uniroyal). Sept 19, 2002. 11 more Pesticide tolerances despite the fact that scientific issues raised by NRDC have not been resolved. Final Rule. Federal Register.

FLUORIDE ACTION NETWORK PESTICIDE PROJECT

Diflubenzuron (IR-4; Uniroyal). September 19, 2002. 11 more Pesticide Tolerances despite the fact that scientific issues raised by NRDC have not been resolved. Final Rule. Federal Register.

http://www.epa.gov/fedrgstr/EPA-PEST/2002/September/Day-19/p23818.htm

[Federal Register: September 19, 2002 (Volume 67, Number 182)]
[Rules and Regulations]
[Page 59006-59017]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr19se02-14]

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

ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-2002-0224; FRL-7200-4]

Diflubenzuron; Pesticide Tolerances

AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.

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

SUMMARY: This regulation establishes tolerances for the combined
residues of the insecticide diflubenzuron (N-[[4-chlorophenyl)amino]-
carbonyl]-2,6-difluorobenzamide) and its metabolites, 4-
chlorophenylurea (CPU) and 4-chloroaniline (PCA) in or on the following
raw agricultural commodities: Grass, forage, fodder, and hay group 17
at 6.0 ppm; pepper at 1.0 ppm; stone fruit group 12 (except cherries)
at 0.07 ppm; nut, tree, group 14 at 0.06 ppm; almond, hulls at 6.0 ppm;
pistachio at 0.06 ppm; cattle, meat byproducts at 0.15 ppm; goat, meat
byproducts at 0.15 ppm; hog, meat byproducts at 0.15 ppm; horse, meat
byproducts at 0.15 ppm; sheep, meat byproducts at 0.15 ppm. This
regulation is increasing the tolerance level for meat byproducts of
cattle, goat, hog, horse, and sheep. This regulation is also changing
the tolerance on pasture grass to grass, forage, fodder, and hay group
17. Interregional Research Project Number 4 (IR-4), and Uniroyal
Chemical Company requested these tolerances under the Federal Food,
Drug, and Cosmetic Act, as amended by the Food Quality Protection Act
of 1996.

DATES: This regulation is effective September 19, 2002. Objections and
requests for hearings, identified by docket control number OPP-2002-
0224, must be received on or before November 18, 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 control number OPP-2002-0224 in
the subject line on the first page of your response.

FOR FURTHER INFORMATION CONTACT: By mail: Rita Kumar, Registration
Division (7505C), Office of Pesticide Programs, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW.,Washington, DC 20460;
telephone number: (703) 308-8291; e-mail address: kumar.rita@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 control number OPP-2002-0224. 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

[[Page 59007]]

the official record, which includes printed, paper versions of any
electronic comments submitted during an applicable comment period is
available for inspection in the Public Information and Records
Integrity Branch (PIRIB), Rm. 119, Crystal Mall #2, 1921
Jefferson Davis Hwy., Arlington, VA, from 8:30 a.m. to 4 p.m., Monday
through Friday, excluding legal holidays. The PIRIB telephone number is
(703) 305-5805.

II. Background and Statutory Findings

In the Federal Register of December 14, 2001 (66 FR 64823) (6813-
2), EPA issued a notice pursuant to section 408 of the Federal Food,
Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a, as amended by the Food
Quality Protection Act of 1996 (FQPA) (Public Law 104-170), announcing
the filing of pesticide petitions (PP 1E6347 and 1F6235) by
Interregional Research Project Number 4 (IR-4), and Uniroyal Chemical
Company Inc., 681 US Highway 1 South, North Brunswick, NJ 08902, and
Middlebury, CT 06749. This notice included a summary of the petitions
prepared by IR-4 and Uniroyal Chemical Company, the registrants. There
were no comments received in response to the notice of filing.
The petitions requested that 40 CFR 180.377 be amended by
establishing a tolerance for the combined residues of the insecticide
diflubenzuron (N-[[4-chlorophenyl)amino]-carbonyl]-2,6-
difluorobenzamide) and its metabolites, 4-chlorophenylurea (CPU) and 4-
chloroaniline (PCA), in or on grass, forage, fodder, and hay, group 17
at 6.0 part per million (ppm); pepper at 1.0 ppm; stone fruit group
(except cherries) at 0.05 ppm; tree nut group at 0.05 ppm; almond,
hulls at 5.0 ppm; pistachio at 0.05 ppm; and meat byproducts at 0.15
ppm.
Section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a
tolerance (the legal limit for a pesticide chemical residue in or on a
food) only if EPA determines that the tolerance is ``safe.'' Section
408(b)(2)(A)(ii) defines ``safe'' to mean that ``there is a reasonable
certainty that no harm will result from aggregate exposure to the
pesticide chemical residue, including all anticipated dietary exposures
and all other exposures for which there is reliable information.'' This
includes exposure through drinking water and in residential settings,
but does not include occupational exposure. Section 408(b)(2)(C)
requires EPA to give special consideration to exposure of infants and
children to the pesticide chemical residue in establishing a tolerance
and to ``ensure that there is a reasonable certainty that no harm will
result to infants and children from aggregate exposure to the pesticide
chemical residue.''
EPA performs a number of analyses to determine the risks from
aggregate exposure to pesticide residues. For further discussion of the
regulatory requirements of section 408 and a complete description of
the risk assessment process, see the final rule on Bifenthrin Pesticide
Tolerances (62 FR 62961, November 26, 1997) (FRL-5754-7).

III. Aggregate Risk Assessment and Determination of Safety

Consistent with section 408(b)(2)(D), EPA has reviewed the
available scientific data and other relevant information in support of
this action. EPA has sufficient data to assess the hazards of and to
make a determination on aggregate exposure, consistent with section
408(b)(2), for a tolerance for residues of the insecticide
diflubenzuron (N-[[4-chlorophenyl)amino]-carbonyl]-2,6-
difluorobenzamide) and its metabolites, 4-chlorophenylurea (CPU) and 4-
chloroaniline (PCA) on grass, forage, fodder, and hay group at 6.0 ppm;
pepper at 1.0 ppm; stone fruit group (except cherries) at 0.07 ppm;
tree nut group at 0.06 ppm; almond hulls at 6.0 ppm; pistachio at 0.06
ppm; cattle, meat byproducts at 0.15 ppm; goat, meat byproducts at 0.15
ppm; hog, meat byproducts at 0.15 ppm; horse, meat byproducts at 0.15
ppm; sheep, meat byproducts at 0.15 ppm.
EPA's assessment of exposures and risks associated with
establishing the tolerances 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 diflubenzuron are
discussed in the following Table 1 as well as the no observed adverse
effect level (NOAEL) and the lowest observed adverse effect level
(LOAEL) from the toxicity studies reviewed.

Table 1.--Subchronic, Chronic, and Other Toxicity
----------------------------------------------------------------------------------------------------------------
Guideline No. Study Type Results
----------------------------------------------------------------------------------------------------------------
870.3100 90-Day oral toxicity NOAEL < 8 mg/kg/day
rodents LOAEL = 8 mg/kg/day based on increased
methemoglobinemia, and signs of hemolytic
anemia, erythrocyte destruction in the
spleen and liver and regeneration of
erythrocytes in the bone marrow.
----------------------------------------------------------------------------------------------------------------
870.3150 90-Day oral toxicity in NOAEL = 2 mg/kg/day
nonrodents LOAEL = 6.24 mg/kg/day based on
methemoglobinemia.
----------------------------------------------------------------------------------------------------------------
870.3200 21/28-Day dermal toxicity NOAEL = 500 mg/kg/day
LOAEL = 1,000 mg/kg/day based on
methemoglobinemia (limit dose).
----------------------------------------------------------------------------------------------------------------
870.3465 28-Day inhalation toxicity NOAEL = 20.3 mg/kg/day highest dose tested
(HDT)
LOAEL was not established.
----------------------------------------------------------------------------------------------------------------
870.3700 Prenatal developmental in Maternal NOAEL = 1,000 mg/kg/day (Limit
rodents Dose)
LOAEL was not established.
Developmental NOAEL = 1,000 mg/kg/day
(Limit Dose)
LOAEL was not established.
----------------------------------------------------------------------------------------------------------------

[[Page 59008]]

870.3700 Prenatal developmental in Maternal NOAEL = 1,000 mg/kg/day (Limit
nonrodents Dose)
LOAEL was not established.
Developmental NOAEL = 1,000 mg/kg/day
(Limit Dose)
LOAEL was not established.
----------------------------------------------------------------------------------------------------------------
870.3800 Reproduction and fertility Parental/Systemic NOAEL < 36 mg/kg/day
effects (LDT)
LOAEL = 36 mg/kg/day based on dose-related
decreased hematocrit, hemoglobin
concentration, red blood cell count and an
increase in percent methemoglobin, changes
in cell morphology and brown pigment in
Kupffer cells.
Reproductive NOAEL> 4254 mg/kg/day (HDT)
LOAEL was not established.
Offspring NOAEL = 427 mg/kg/day
LOAEL = 4254 mg/kg/day based on Significant
decrease in F-1 pup weights on day 4, 8
and 21 of lactation.
----------------------------------------------------------------------------------------------------------------
870.4100 Chronic toxicity dogs NOAEL = 2 mg/kg/day
LOAEL = 10 mg/kg/day based on
methemoglobinemia and sulfhemoglobinemia.
----------------------------------------------------------------------------------------------------------------
870.4200 Carcinogenicity rats NOAEL was not established
LOAEL = 7.8 mg/kg/day based on histological
evidence of erythrocyte destruction and
compensatory regeneration.
No evidence of carcinogenicity
----------------------------------------------------------------------------------------------------------------
870.4300 Carcinogenicity mice NOAEL = 2.4 mg/kg/day LOAEL = 12 mg/kg/day
based on increased methemoglobin and
sulfhemoglobin levels.
No evidence of carcinogenicity
----------------------------------------------------------------------------------------------------------------
870.5100 Gene Mutation Salmonella strains TA98, TA100, TA1535,
TA1537 and TA1538 exposed to diflubenzuron
in DMSO at doses of 0 to 1,000 [mu]g/plate
both in the presence and absence of S9 did
not induce mutations.
----------------------------------------------------------------------------------------------------------------
870.5375 Cytogenetics Chinese hamster ovary cells in vitro
exposure to diflubenzuron in DMSO at dose
levels of 200 to 250 [mu]g/mL both in the
presence and absence of S9 did not induce
an increase in chromosomal aberrations.
----------------------------------------------------------------------------------------------------------------
870.5550 Other Effects In the UDS assay primary rat hepatocytes
exposed to diflubenzuron in DMSO at dose
levels of 0.1 to 333 [mu]g/mL did not
induce unscheduled DNA syntheses.
----------------------------------------------------------------------------------------------------------------
870.7485 Metabolism and [\14\C-anilino]-diflubenzuron was
pharmacokinetics completely absorbed and 87% of
radioactivity was recovered in the urine
and feces as parent, diflubenzuron by 96
hours post-dosing. Diflubenzuron did not
metabolize to 4-chloroaniline (CPA), or
chlorophenylurea (CPU); the former was
associated with methemoglobin formation
and tumor formation in rats and mice in
the NTP study.
[U-\14\C-phenyl]-chlorophenylurea (CPU) was
completely absorbed and 91% of the dose
was eliminated in urine and feces by 144
hours. Unmetabolized CPU was not
identified in urine or feces. Most of
urinary/fecal metabolites were sulfate or
glucuronide conjugates of CPU.
----------------------------------------------------------------------------------------------------------------
870.7600 Dermal penetration Dermal application of \14\C) diflubenzuron
at either 0.005 or 0.05 mg/cm.sq. resulted
in less than 0.5% absorption at any dose
level after 1, 4 or 10 hours of exposure.
----------------------------------------------------------------------------------------------------------------
N/A Special studies In acute oral toxicity study in rats CPA at
62 mg/kg caused significant increase in
methemoglobinemia while CPU at 200 mg/kg
did not cause methemoglobinemia.
----------------------------------------------------------------------------------------------------------------

B. Toxicological Endpoints

The dose at which 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
the LOAEL is sometimes used for risk assessment if no NOAEL was
achieved in the toxicology study selected. An uncertainty factor (UF)
is applied to reflect uncertainties inherent in the extrapolation from
laboratory animal data to humans and in the variations in sensitivity
among members of the human population as well as other unknowns. An UF
of 100 is routinely used, 10X to account for interspecies differences
and 10X for intra species differences.
The FQPA Safety Factor Committee (SFC) recommended that the FQPA
safety factor used in human health risk assessments (as required by
FQPA of August 3, 1996) be removed (reduced to 1x) in assessing the
risk posed by this chemical. Consequently, the current cRfD and cPAD
values are equivalent (0.02 mg/kg/day). This decision was based on the
following:
1. There is no indication of quantitative or qualitative increased
susceptibility of rats or rabbits to in utero or postnatal exposure;
2. A developmental neurotoxicity study (DNT) with diflubenzuron is
not required;
3. Food and drinking water exposure assessments will not
underestimate the potential exposure for infants and children; and
4. There are currently no registered or proposed residential (non-
occupational) uses of diflubenzuron. Although there are no registered
homeowner uses, there

[[Page 59009]]

is potential for professional applications to outdoor residential and
recreational areas to control mosquitos, moths, and other insects.
However, the potential for post-application residential exposures are
expected to be limited. Due to the low dermal absorption rate (0.5%) of
diflubenzuron, and since it is only applied to the tree canopy, minimal
bystander contact is expected.
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 diflubenzuron and its metabolites used for human risk
assessment is shown in the following Table 2:

Table 2.--Summary of Toxicological Dose and Endpoints for Diflubenzuron and its Metabolites for Use in Human
Risk Assessment\1\.
----------------------------------------------------------------------------------------------------------------
Dose Used in Risk FQPA SF** and LOC for Study and Toxicological
Exposure Scenario Assessment, UF Risk Assessment Effects
----------------------------------------------------------------------------------------------------------------
Acute Dietary all populations Not Applicable Not Applicable No appropriate endpoint
attributable to single
exposure was available
in oral studies.
Therefore, a risk
assessment is not
required.
----------------------------------------------------------------------------------------------------------------
Chronic Dietary (All populations) NOAEL= 2 mg/kg/day FQPA SF = 1x Chronic Toxicity Study
UF = 100............... cPAD = chronic RfD/FQPA Dog
Chronic RfD = 0.02 mg/ SF. LOAEL = 10 mg/kg/day
kg/day. = 0.02 mg/kg/day....... based on
methemoglobinemia and
sulfhemoglobinemia
----------------------------------------------------------------------------------------------------------------
Short- and Intermediate- Term Not applicable Not applicable These endpoints were
Incidental Oral (1 day-6 months) not evaluated. There
(Residential) are no registered uses
of diflubenzuron which
result in significant
residential exposure.
----------------------------------------------------------------------------------------------------------------
Short- Term Dermal (1-30 days) NOAEL = 500 mg/kg/day LOC for MOE = 100 21-Day dermal rat
(Occupational) LOAEL = 1,000 mg/kg/day
based on
methemoglobinemia
----------------------------------------------------------------------------------------------------------------
Intermediate-Term Dermal (1-6 months) NOAEL = 2 mg/kg/day LOC for MOE = 100 13 - week oral dog
(Occupational) LOAEL = 6.4 mg/kg/day
based on
methemoglobinemia
----------------------------------------------------------------------------------------------------------------
Long- Term Dermal (Longer than 6 NOAEL = 2 mg/kg/day LOC for MOE = 100 Chronic Toxicity Study
months) (Occupational) Dog
LOAEL = 10 mg/kg/day
based on
methemoglobinemia and
sulfhemoglobinemia
----------------------------------------------------------------------------------------------------------------
Short- Term Inhalation (1-30 days) NOAEL = 20.30\2\ mg/kg/ LOC for MOE = 100 28-day Inhalation
(Occupational) day Toxicity Study - Rat/
21-day Inhalation
Toxicity Study - Rat
LOAEL = 0.12 mg/L based
on methemoglobinemia
(21-day study)
----------------------------------------------------------------------------------------------------------------
Intermediate-Term Inhalation (1-6 NOAEL = 20.30\2\ mg/kg/ LOC for MOE = 100 28-day Inhalation
months) (Occupational) day Toxicity Study - Rat/
21-day Inhalation
Toxicity Study - Rat
LOAEL = 0.12 mg/L based
on methemoglobinemia
(21-day study)
----------------------------------------------------------------------------------------------------------------
Long - Term Inhalation (Longer than 6 NOAEL = 2 mg/kg/day LOC for MOE = 100 Chronic Toxicity Study
months) (Occupational) (Occupational) Dog
LOAEL = 10 mg/kg/day
based on
methemoglobinemia and
sulfhemoglobinemia
----------------------------------------------------------------------------------------------------------------
Cancer (Oral, dermal, inhalation) Diflubenzuron Not Not Applicable Acceptable oral rat and
Required mouse carcinogenicity
studies; no evidence
of carcinogenic or
mutagenic potential.
Group E evidence of
non-carcinogenicity
for humans.
----------------------------------------------------------------------------------------------------------------

[[Page 59010]]

Cancer (Oral, dermal, inhalation) PCA Group B2 probably Not Applicable NTP Oral mouse study
human carcinogen Q1*
1.12 x 1-\1\ (mg/kg/
day)-\1\
----------------------------------------------------------------------------------------------------------------
Cancer (Oral, dermal, inhalation) CPU Q₁* based on Not Applicable NTP Oral rat study
monuron a structural
analog and the Q₁*1.52
x 10-\2\
----------------------------------------------------------------------------------------------------------------
\1\UF = uncertainty factor, FQPA SF = FQPA safety factor, NOAEL = no observed adverse effect level, LOAEL =
lowest observed adverse effect level, cPAD = chronic population adjusted dose, RfD = reference dose, MOE =
margin of exposure, LOC = level of concern.
\2\Conversion from mg/L to oral dose (mg/kg/day)
* 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 180.377) for the combined residues of the
insecticide diflubenzuron (N-[[4-chlorophenyl)amino]-carbonyl]-2,6-
difluorobenzamide and its metabolites, in or on a variety of raw
agricultural commodities. Risk assessments were conducted by EPA to
assess dietary exposures from diflubenzuron and its metabolites in food
as follows:
i. Acute exposure. Acute dietary risk assessments are performed for
a food-use pesticide if a toxicological study has indicated the
possibility of an effect of concern occurring as a result of a one day
or single exposure. Acute doses and endpoints were not selected for the
general U.S. population (including infants and children) or the females
13-50 years old population subgroup for diflubenzuron; therefore, an
acute dietary exposure analysis was not performed.
ii. Chronic exposure. In conducting this chronic dietary risk
assessment the Dietary Exposure Evaluation Model (DEEM\TM\) analysis
evaluated the individual food consumption as reported by respondents in
the USDA 1989-1992 nationwide Continuing Surveys of Food Intake by
Individuals (CSFII) and accumulated exposure to the chemical for each
commodity. The following assumptions were made for the chronic exposure
assessments:
For the chronic analysis, anticipated residue (AR) information
based on field trial data and percent crop treated (%CT) information
for some commodities were used. Dietary exposure estimates for
representative population subgroups are presented in Table 3. Chronic
exposure estimates are expressed in mg/kg bw/day and as a percent of
the cPAD. The chronic dietary risk assessment also indicates that for
all included commodities, the chronic dietary risk estimates are below
Agency's level of concern (<100% cPAD) for the general U.S. population
(<1.0% of the cPAD) and all population subgroups. The chronic dietary
exposure estimate for the highest exposed population subgroup (all
infants (<1 year old)) is 5.5% of the cPAD.

Table 3.--Results of Chronic Dietary Exposure Analysis.
----------------------------------------------------------------------------------------------------------------
Population Subgroup cPAD (mg/kg/day) Exposure (mg/kg/day) % cPAD
----------------------------------------------------------------------------------------------------------------
U.S. Population (Total) 0.02 0.000153 < 1.0
----------------------------------------------------------------------------------------------------------------
All Infants (> 1 year old) 0.02 0.001109 5.5
----------------------------------------------------------------------------------------------------------------
Children 1-6 years old 0.02 0.000248 1.2
----------------------------------------------------------------------------------------------------------------
Children 7-12 years old 0.02 0.000199 1.0
----------------------------------------------------------------------------------------------------------------
Females 13-50 years old 0.02 0.000112 < 1.0
----------------------------------------------------------------------------------------------------------------
Males 13-19 years old 0.02 0.000065 < 1.0
----------------------------------------------------------------------------------------------------------------
Males 20+ years old 0.02 0.000124 < 1.0
----------------------------------------------------------------------------------------------------------------
Seniors 55+ years old 0.02 0.000144 < 1.0
----------------------------------------------------------------------------------------------------------------

iii. Cancer. In 1995, based on the available evidence, which
included carcinogenicity studies in rats and mice, and battery of
negative mutagenicity studies, diflubenzuron was classified as Group E,
evidence of non-carcinogenicity for humans. Rat metabolism data
generated at this time also indicated that diflubenzuron was
metabolized to PCA and CPU and estimated to be about 2% of in vivo
conversion.
At that time, EPA also considered the carcinogenicity of PCA, a
known diflubenzuron metabolite, that was tested by the NTP in 1989 for
carcinogenicity in rats and mice as a hydrochloride form. In rats
treated with PCA, a treatment-related increased incidence of uncommon
sarcomas of the spleen was observed in males and included
fibrosarcomas, hemangiosarcomas, and osteosarcomas, many of which
metastasized to other sites. In addition, in treated females, one
fibrosarcoma and one osteosarcoma were also observed. Furthermore,
there

[[Page 59011]]

was a marginally-increased incidence of pheochromocytomas in the
adrenal glands in both males and females at the HDT. In mice treated
with PCA, a treatment-related increased incidence of combined
hepatocellular adenomas/carcinomas was observed in males. The increase
in combined tumors was primarily due to a dose-related increase in
hepatocellular carcinomas. Many of these tumors metastasized to the
lungs. An increased incidence of hemangiosarcomas in the spleen and/or
liver of the male mice was also observed at the HDT. The incidence was
higher than the historical control mean for male mice. There was no
evidence of a carcinogenic response in female mice. On this basis PCA
was classified as a Group B2, probable human carcinogen.
Recently submitted tier 2 rat metabolism data indicate that
diflubenzuron does not metabolize to PCA or CPU nor is CPU converted to
PCA. The Agency concluded that a 2% in vivo conversion factor for
diflubenzuron to PCA or CPU should be dropped. It was recommended that
non-carcinogenic risk assessment should include parent, CPU and PCA;
and cancer risk for CPU and PCA should be assessed individually.
The Q₁* (estimated unit risk) for PCA, based on male
mouse liver adenoma and/or carcinoma combined tumor rates was
calculated to be 1.12 x 10-\1\ (mg/kg/day)-\1\ in
human equivalents.
CPU is structurally related to monuron (N,N-dimethyl-CPU), a
compound producing tumors of the kidney and liver in male rats. Given
that there is no accepted mechanism of carcinogenicity for monuron and
that CPU is major metabolite of monuron in rats, a Q₁* was
calculated for monuron and applied to CPU. The most potent
Q₁* for monuron, based on male rat liver neoplastic nodule
and/or carcinoma combined tumor rats, was calculated to be 1.52 x
10-\2\ (mg/kg/day)-\1\ in human equivalents.
Although CPU is structurally related to monuron, there is no need to
assess aggregate or cumulative risk scenarios using monuron because
monuron is no longer a registered pesticide active ingredient.
a. Cancer risk from consumption of PCA and CPU. Based on the
submitted metabolism studies, there are two possible sources for
dietary exposure to PCA and CPU: Residues in plants/fungi (mushrooms)
and residues in animal commodities (milk and liver).
b. Mushrooms/Milk/Liver. EPA used results from metabolism studies
to determine the percent of the total radioactive residue (TRR) present
as PCA+CPU in mushrooms, milk and liver. For milk and liver, ARs were
calculated from the results of the ruminant feeding study using
tolerance level residues in livestock feed items and adjusting for
percent crop treated. The total levels of PCA+CPU were estimated by
multiplying the ratio of (PCA+CPU)/Diflubenzuron by the diflubenzuron
consumption (from DEEM). The U.S. population exposure to PCA and CPU is
given in Table 4 as follows.

Table 4.--Dietary Cancer Exposure (to PCA and CPU).
--------------------------------------------------------------------------------------------------------------------------------------------------------
(PCA+CPU)/ Diflubenzuron PCA+CPU
Commodity Diflubenzuron Consumption mg/kg/ Consumption mg/kg/ CPU/(PCA+CPU) PCA Consumption mg/ CPU Consumption mg/
Ratio day day Ratio kg/day kg/day
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mushrooms 3.45 0.0000018 0.0000062 0.33\1\ 0.0000042 0.00000205
--------------------------------------------------------------------------------------------------------------------------------------------------------
Milk 1.33 0.0000003 0.0000004 1.02 0 0.0000004
--------------------------------------------------------------------------------------------------------------------------------------------------------
Liver 0.21 0.0000008 0.00000017 0.97 5 x 10-\9\ 0.00000016
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total 0.0000068 0.0000042 0.0000026
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\Worst case ratio.
Overall U.S. exposure to PCA (Table 4): 0.0000042 mg/kg/day
Carcinogenic Risk: 4.7 x 10-\7\ (0.0000042 mg/kg/day x 0.112 (mg/kg/day)-\1\)
Overall U.S. exposure to CPU (Table 4): 0.0000026 mg/kg/day
Carcinogenic Risk: 3.9 x 10-\87\ (0.0000026 mg/kg/day x 0.0152 (mg/kg/day)-\1\)

The Agency does not consider the cancer dietary risk from either
PCA or CPU to exceed the Agency's level of concern (generally, in the
range of 10-\6\).
iv. Anticipated residue and percent crop treated information.
Section 408(b)(2)(E) authorizes EPA to use available data and
information on the anticipated residue levels of pesticide residues in
food and the actual levels of pesticide chemicals that have been
measured in food. If EPA relies on such information, EPA must require
that data be provided 5 years after the tolerance is established,
modified, or left in effect, demonstrating that the levels in food are
not above the levels anticipated. Following the initial data
submission, EPA is authorized to require similar data on a time frame
it deems appropriate. As required by section 408(b)(2)(E), EPA will
issue a data call-in for information relating to anticipated residues
to be submitted no later than 5 years from the date of issuance of this
tolerance.
Section 408(b)(2)(F) states that the Agency may use data on the
actual percent of food treated for assessing chronic dietary risk only
if the Agency can make the following findings: Condition 1, that the
data used are reliable and provide a valid basis to show what
percentage of the food derived from such crop is likely to contain such
pesticide residue; Condition 2, that the exposure estimate does not
underestimate exposure for any significant subpopulation group; and
Condition 3, if data are available on pesticide use and food
consumption in a particular area, the exposure estimate does not
understate exposure for the population in such area. In addition, the
Agency must provide for periodic evaluation of any estimates used. To
provide for the periodic evaluation of the estimate of percent crop
treated (PCT) as required by section 408(b)(2)(F), EPA may require
registrants to submit data on PCT.
The Agency used percent crop treated (PCT) information as follows.
Dietary exposure estimates were based on the following percent crop
treated (PCT) estimates: Grass, 1%; grapefruit, 8%; mushrooms, 31%;
oranges, 2%; tangerines, 4%; cottonseed oil and meal, 2%; soybean, 1%;
cattle bolus, 5%, walnuts 50%. Other commodities were assumed to be 100
percent treated. Anticipated residue levels for diflubenzuron were
calculated in livestock, citrus and mushroom commodities. Anticipated
residue estimates for diflubenzuron were not calculated for other raw
agricultural commodities. Percent crop treated data were utilized where
available.

[[Page 59012]]

The Agency believes that the three conditions listed above
regarding percent crop treated information have been met. With respect
to Condition 1, PCT estimates are derived from Federal and private
market survey data, which are reliable and have a valid basis. EPA uses
a weighted average PCT for chronic dietary exposure estimates. This
weighted average PCT figure is derived by averaging State-level data
for a period of up to 10 years, and weighting for the more robust and
recent data. A weighted average of the PCT reasonably represents a
person's dietary exposure over a lifetime, and is unlikely to
underestimate exposure to an individual because of the fact that
pesticide use patterns (both regionally and nationally) tend to change
continuously over time, such that an individual is unlikely to be
exposed to more than the average PCT over a lifetime. For acute dietary
exposure estimates, EPA uses an estimated maximum PCT. The exposure
estimates resulting from this approach reasonably represent the highest
levels to which an individual could be exposed, and are unlikely to
underestimate an individual's acute dietary exposure. The Agency is
reasonably certain that the percentage of the food treated is not
likely to be an underestimation. As to Conditions 2 and 3, regional
consumption information and consumption information for significant
subpopulations is taken into account through EPA's computer-based model
for evaluating the exposure of significant subpopulations including
several regional groups. Use of this consumption information in EPA's
risk assessment process ensures that EPA's exposure estimate does not
understate exposure for any significant subpopulation group and allows
the Agency to be reasonably certain that no regional population is
exposed to residue levels higher than those estimated by the Agency.
Other than the data available through national food consumption
surveys, EPA does not have available information on the regional
consumption of food to which diflubenzuron may be applied in a
particular area.
2. Dietary exposure from drinking water. The Agency lacks
sufficient monitoring exposure data to complete a comprehensive dietary
exposure analysis and risk assessment for diflubenzuron (N-[[4-
chlorophenyl)amino]-carbonyl]-2,6-difluorobenzamide) and its
metabolites, 4-chlorophenylurea (CPU) and 4-chloroaniline (PCA) 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 diflubenzuron (N-[[4-chlorophenyl)amino]-
carbonyl]-2,6-difluorobenzamide) and its metabolites, 4-
chlorophenylurea (CPU) and 4-chloroaniline (PCA).
The Agency uses the FQPA Index Reservoir Screening Tool (FIRST) or
the Pesticide Root Zone Model/Exposure Analysis Modeling System (PRZM/
EXAMS), to produce estimates of pesticide concentrations in an index
reservoir. The SCI-GROW model is used to predict pesticide
concentrations in shallow groundwater. For a screening-level assessment
for surface water EPA will use FIRST (a tier 1 model) before using
PRZM/EXAMS (a tier 2 model). The FIRST model is a subset of the PRZM/
EXAMS model that uses a specific high-end runoff scenario for
pesticides. While both FIRST and PRZM/EXAMS incorporate an index

reservoir environment, 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 diflubenzuron they are
further discussed in the aggregate risk sections.
Based on the PRZM/EXAMS and SCI-GROW models the estimated
environmental concentrations (EECs) of diflubenzuron and CPU are
estimated to be 0.99 ppb (diflubenzuron) and 8.81 ppb (CPU) for surface
water and 0.0023 ppb (diflubenzuron) and 0.065 ppb (CPU) for ground
water. PCA is not a significant metabolite in the environment.
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). Although there are no
registered homeowner uses for diflubenzuron, there is potential for
professional applications to outdoor residential and recreational areas
to control mosquitos, moths, and other insects. However, due to the low
dermal absorption rate (0.05%) and extremely low dermal and inhalation
toxicity, exposure through these uses is expected to be insignificant,
and residential post-application exposure was not quantitatively
evaluated.
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 diflubenzuron 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,
diflubenzuron 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 diflubenzuron 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

[[Page 59013]]

safety will be safe for infants and children. Margins of safety are
incorporated into EPA risk assessments either directly through use of a
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. Based on the developmental
and reproductive toxicity studies summarized in Table 1, there is no
indication of quantitative or qualitative increased susceptibility of
rats or rabbits to in utero or postnatal exposure.
3. Conclusion. There is a complete toxicity data base for
diflubenzuron and exposure data are complete or are estimated based on
data that reasonably accounts for potential exposures. Based on the
developmental and reproductive data available, EPA determined that the
10X safety factor to protect infants and children (as required by FQPA)
should be removed. This decision was based on the following:
i. There is no indication of quantitative or qualitative increased
susceptibility of rats or rabbits to in utero or postnatal exposure;
ii. A developmental neurotoxicity study (DNT) with diflubenzuron is
not required;
iii. Food and drinking water exposure assessments will not
underestimate the potential exposure for infants and children; and
iv. There are currently no registered or proposed residential (non-
occupational) uses of diflubenzuron for homeowners. Although there are
no registered homeowner uses, there is potential for professional
applications to outdoor residential and recreational areas to control
mosquitos, moths, and other insects. However, the potential for post-
application residential exposures are expected to be limited. Due to
the low dermal absorption rate (0.5%) of diflubenzuron, and since it is
only applied to the tree canopy to control gypsy moths and mosquitoes,
minimal bystander contact is expected.
Recently, EPA has received objections to a tolerance it established
for residues of diflubenzuron in or on pears. The objections were filed
by the Natural Resources Defense Council (NRDC) and raised several
issues regarding aggregate exposure estimates and the additional safety
factor for the protection of infants and children.
NRDC's objections raise complex legal, scientific, policy, and
factual matters and EPA has initiated a public comment period on them
in the Federal Register of June 19, 2002 (67 FR 41628) (FRL-7167-7),
which ends on September 17, 2002. Although that proceeding remains
ongoing, prior to acting on this current tolerance action, EPA reviewed
the diflubenzuron-specific objections raised by NRDC and has addressed
them below.
NRDC claims datagaps include missing residue chemistry and
toxicology data for two diflubenzuron metabolites, deemed necessary by
EPA to justify an unconditional registration.
EPA determined that the toxicology database for diflubenzuron is
complete for assessment of increased susceptibility to infants and
children as required by the Food Quality Protection Act (FQPA) . There
are no data gaps for the assessment of the effects of diflubenzuron
following in utero and/or postnatal exposure. There was no evidence
that diflubenzuron targets the nervous system; neither clinical signs
indicative of neurotoxicity nor neuropathology were seen in any of the
acute, subchronic or chronic studies. There are reliable data that
indicate there are (residual) concerns for pre-and/or post-natal
toxicity. There was no evidence (quantitative or qualitative) of
increased susceptibility following in utero exposure to rats or rabbits
or to postnatal exposure to rats. In the prenatal developmental
toxicity studies in rats and rabbits, no developmental toxicity was
seen at the Limit Dose (1,000 mg/kg/day) and in the two-generation
reproduction study in rats toxicity in the offspring was manifested as
decreased body weight at approximately 4,000 mg/kg/day (4 times the
Limit Dose). Based on the lack of evidence of neurotoxic potential and
increased susceptibility, EPA determined that a developmental
neurotoxicity study in rats was not required.
The Agency believes that it has sufficient data for the
metabolites, PCA and CPU because the rate of metabolism of
diflubenzuron to PCA or CPU in plants, ruminants, and the environment
is low and, thus, exposure to these metabolites will be minimal.
Adequate data are available to assess the cancer risks for both PCA and
CPU. Even using the most conservative cancer risk assessment model,
which is the low dose linear model, risk is negligible. EPA's
experience is that a risk assessment using a low dose linear cancer
assessment will be the most sensitive risk endpoint indicating that
additional hazard testing for these metabolites will not lead to a more
protective regulatory decision.
NRDC also claims that by relying on anticipated residue estimates
for diflubenzuron on certain crops EPA vastly underestimates dietary
exposure. This underestimation occurs, according to NRDC because EPA
does not take into account that a significant number of consumers buy
produce at farm stands. Even assuming that exposure as a result of
purchases at farm stands constitute more than a negligible exposure,
NRDC's claims here are inaccurate. Anticipated residues are based on
data from crop field trials using application rates and procedures that
will produce maximum residues under the currently-approved pesticide
label at the time of harvest. As such, they are likely to overstate not
understate residue levels of crops at farm stands.
Finally, NRDC asserts that EPA has underestimated aggregate
exposure to diflubenzuron because EPA concluded that application of
diflubenzuron to tree canopies would result in negligible residential
exposure to diflubenzuron. After review, however, EPA reaffirms that
these potential exposures are expected to be limited. The label states
that ``applications should be made during periods of minimal use.'' and
requires users to ``Notify persons using recreational facilities or
living in the area to be sprayed before application.'' Diflubenzuron is
only applied by commercial applicators to the tree canopy for control
of gypsy moths and mosquitoes. Generally applied by helicopter, these
sprays are not aerosols or ultra low volume sprays designed as space
sprays, but are rather directed to the tree canopy and designed to
impinge on the tree tops where they would be effective in pest control.
The sprays designed for application to tree canopies utilize much
larger droplet sizes which are essentially nonrespirable; therefore,
minimal inhalation exposure to bystanders is expected. Additionally,
due to a low dermal absorption rate (0.5%), the potential for dermal
exposure to bystanders is expected to be minimal.
In any event, EPA would note that the results of the chronic
dietary analysis indicated that the estimated chronic dietary risk
associated with the proposed use of diflubenzuron was well below the
Agency's level of concern for the general U.S. population. In fact, the
highest exposed population subgroup (all infants < 1 years of age) is
5.5% of the PAD. The PAD is the Population Adjusted Dose, which is the
Reference Dose (RfD) divided by the FQPA Safety Factor. The Agency's
level of concern is for exposures in excess of 100% of the PAD. An
acute dietary exposure risk assessment was not conducted since no
hazard was identified for any population, including infants and
children, following a single exposure to diflubenzuron (i.e., no hazard
was

[[Page 59014]]

identified, therefore, quantification of risk is not required).

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 USEPA Office of Water are used to calculate
DWLOCs: 2L/70 kg (adult male), 2L/60 kg (adult female), and 1L/10 kg
(child). Default body weights and drinking water consumption values
vary on an individual basis. This variation will be taken into account
in more refined screening-level and quantitative drinking water
exposure assessments. Different populations will have different DWLOCs.
Generally, a DWLOC is calculated for each type of risk assessment used:
Acute, short-term, intermediate-term, chronic, and cancer.
When EECs for surface water and groundwater are less than the
calculated DWLOCs, OPP concludes with reasonable certainty that
exposures to the pesticide in drinking water (when considered along
with other sources of exposure for which OPP has reliable data) would
not result in unacceptable levels of aggregate human health risk at
this time. Because OPP considers the aggregate risk resulting from
multiple exposure pathways associated with a pesticide's uses, levels
of comparison in drinking water may vary as those uses change. If new
uses are added in the future, OPP will reassess the potential impacts
of residues of the pesticide in drinking water as a part of the
aggregate risk assessment process.
1. Acute risk. There is no risk from acute dietary exposure (1 day)
to diflubenzuron as there is no toxic endpoint identified.
2. Chronic risk. Using the exposure assumptions described in this
unit for chronic exposure, EPA has concluded that exposure to
diflubenzuron and its metabolite CPU from food will utilize 1% of the
cPAD for the U.S. population, 5.5% of the cPAD for infants and 1.2% of
the cPAD for children 1-6 years old. Based on the use pattern, chronic
residential exposure to residues of diflubenzuron is not expected. In
addition, there is potential for chronic dietary exposure to
diflubenzuron and its metabolite CPU 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 cPAD, as shown in Table 5 below.
For the chronic analysis, ARs and %CT information for some
commodities were used (Tier 3). The results of the chronic analysis for
diflubenzuron indicate that the estimated chronic dietary risk
associated with the proposed use of diflubenzuron is below HED's level
of concern. The EECs generated by EFED are less than HED's DWLOCs.
Thus, chronic non-cancer aggregate risk estimates are below HED's level
of concern. Table 5 summarizes the chronic non-cancer aggregate
exposure to diflubenzuron residues.

Table 5.--Aggregate Risk Assessment for Chronic (Non- Cancer) Exposure to Diflubenzuron and CPU
----------------------------------------------------------------------------------------------------------------
Ground Surface Chronic
Scenario/Population Subgroup cPAD, mg/kg/ %cPAD Water EEC, Water DWLOC\2\,
day (Food) ppb EEC\1\, ppb ppb
----------------------------------------------------------------------------------------------------------------
U.S. population 0.02 <1.0 0.067 9.8 700
----------------------------------------------------------------------------------------------------------------
All infants (<1 year old) 0.02 5.5 0.067 9.8 190
----------------------------------------------------------------------------------------------------------------
Children (1-6 years old) 0.02 1.2 0.067 9.8 200
----------------------------------------------------------------------------------------------------------------
Children (7-1 2 years old) 0.02 1.0 0.067 9.8 200
----------------------------------------------------------------------------------------------------------------
Females (13-50 years old) 0.02 <1.0 0.067 9.8 700
----------------------------------------------------------------------------------------------------------------
Males (13-19 years old) 0.02 <1.0 0.067 9.8 700
----------------------------------------------------------------------------------------------------------------
Males (20+ years old) 0.02 < 1.0 0.067 9.8 700
----------------------------------------------------------------------------------------------------------------
Seniors (55+ years old) 0.02 < 1.0 0.067 9.8 700
----------------------------------------------------------------------------------------------------------------
\1\ EECs for diflubenzuron + CPU resulting from the worst-case water exposure estimate scenario (peppers).
\2\ The chronic DWLOCs were calculated as follows:
DWLOC ([mu]g/L) = maximumwater exposure (mg/kg/day)/consumption (L/day) x 0.001 mg/[mu]g x body weight(kg)

3. Short-term risk. Short-term aggregate exposure takes into
account residential exposure plus chronic exposure to food and water
(considered to be a background exposure level). Diflubenzuron is not
registered for use on any sites that would result in substantial
residential exposure. Therefore, a short-term aggregate risk assessment
was not performed.
4. Intermediate-term risk. Intermediate-term aggregate exposure
takes into account residential exposure plus chronic exposure to food
and water (considered to be a background exposure level). Based on the
use pattern, intermediate-term exposure to diflubenzuron would not be
expected. Therefore, an intermediate-term aggregate risk assessment was
not performed.
5. Aggregate cancer risk for U.S. population. As discussed in the
Exposure Assessment in Unit. III.C. of this document, CPU is the only
metabolite of concern for aggregate cancer risk that is likely to be
found in drinking water. For the chronic analysis, ARs and %CT
information for some

[[Page 59015]]

commodities were used (Tier 3). The results of the cancer analysis
indicate that the estimated cancer dietary risk from CPU associated
with the proposed use of diflubenzuron is below the Agency's level of
concern. Based on a negligible risk in the range of 1-3 x
10-\6\, the DWLOCs were calculated to be in the range of
2.2-6.8 [mu]g/L. The EECs for surface water (8.81 [mu]g/L) slightly
exceed the DWLOCs.
Since PCA is not found in drinking water, the aggregate cancer risk
for PCA is the risk calculated for food only (4.7 x 10-\7\).
The Agency used a screening level model designed to estimate
pesticide concentrations in surface water. Although the cancer DWLOC is
exceeded by the EEC for CPU on peppers, a number of factors lead the
Agency to believe that the actual lifetime exposure through drinking
water from the metabolite CPU will be less than the cancer DWLOC. An
explanation is provided below:
i. The dietary risk for CPU is minimal from mushrooms, milk, and
liver. Therefore, the dietary risk from CPU occurs mostly from exposure
that results from its formation in the environment and leaching into
the surface water as a result of field application.
ii. The PRZM/EXAMS model does not consider the impact of processing
(mixing, dilution, or treatment) of raw water for distribution of
drinking water and removal of pesticides from source water.
iii. In the absence of reliable monitoring data, a default percent
crop area (PCA) factor is applied to the PRZM/EXAMS modeling. Although
the DWLOC is exceeded for peppers, the PCA factor of 87% that was used
in the assessment is likely to be higher than the actual factor that
would be appropriate for peppers in an agricultural watershed.
iv. To address the uncertainties caused by the absence of reliable
monitoring data, the applicant has agreed to conduct edge-of-field
runoff studies for peppers to monitor the actual concentrations of CPU
in surface water. These data, albeit still relevant solely for
estimation of residues in raw water and thus still likely to
overestimate residues in actual drinking water, are likely to lower the
upper bound risk estimate considerably.
6. Determination of safety. Based on these risk assessments, EPA
concludes that there is a reasonable certainty that no harm will result
to the general population, and to infants and children from aggregate
exposure to diflubenzuron residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

Adequate methods are available for the analysis of diflubenzuron,
PCA, and CPU in crops. Three enforcement methods for diflubenzuron are
published in the Pesticide Analytical Method Volume II (PAM II) as
Methods I, II, and III. Method II is a GC/ECD method that can
separately determine residues of diflubenzuron, CPU, and PCA in eggs,
milk, and livestock tissues. All three methods have undergone a
successful petition method validation (PMV) and are acceptable for
enforcement purposes. Individual analyte methods for CPU (limit of
quantitation (LOQ) of 0.001 ppm) and PCA (LOQ of 0.005 ppm) have been
successfully validated by the Analytical Chemistry Branch (ACB).
Multiresidue Method (MRM). The FDA PESTDATA database dated 1/94
(PAM Vol. I, Appendix II) contains no information on diflubenzuron
recovery using MRM PAM, Vol. I Sections 302, 303, and 304. However, the
registrant has submitted Multiresidue testing data that the Agency has
forwarded to the FDA. Also, the results of MRM testing of PCA and CPU
have been submitted and forwarded to FDA. Neither PCA nor CPU were
adequately recovered by any protocols.

B. International Residue Limits

There are no Codex proposals, Canadian, or Mexican limits for
residues of diflubenzuron on rice. A compatibility issue is not
relevant to the proposed tolerances.

C. Conditions

Environmental fate. Edge of field monitoring study for peppers.

V. Conclusion

Therefore, the tolerance is established for combined residues of
the insecticide diflubenzuron (N-[[4-chlorophenyl)amino]-carbonyl]-2,6-
difluorobenzamide) and its metabolites, 4-chlorophenylurea (CPU) and 4-
chloroaniline (PCA), in or on the following raw agricultural
commodities: Grass, forage, fodder, and hay group at 6.0 ppm; pepper at
1.0 ppm; stone fruit group (except cherries) at 0.07 ppm; tree nut
group at 0.06 ppm; almond hulls at 6.0 ppm; pistachio at 0.06 ppm;
cattle, meat byproducts at 0.15 ppm; goat, meat byproducts at 0.15 ppm;
hog, meat byproducts at 0.15 ppm; horse, meat byproducts at 0.15 ppm;
sheep, meat byproducts at 0.15 ppm. The tolerances for pasture grass
and walnut will be deleted, concomitant with the establishment of the
tree nut group and grass, forage, fodder, and hay group tolerances.

VI. Objections and Hearing Requests

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

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

You must file your objection or request a hearing on this
regulation in accordance with the instructions provided in this unit
and in 40 CFR part 178. To ensure proper receipt by EPA, you must
identify docket control number OPP-2002-0224 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 November
18, 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

[[Page 59016]]

Pennsylvania Ave., NW., Washington, DC 20460. You may also deliver your
request to the Office of the Hearing Clerk in Rm. 104, Crystal Mall
#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 control number OPP-2002-0224, 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

[[Page 59017]]

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: September 11, 2002.
Peter Caulkins,
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 180.377 is amended as follows:
i. By removing the entries for ``Cattle, meat byproducts''; ``Goat,
meat byproducts''; ``Hog, meat byproducts''; ``Horse, meat
byproducts''; ``Sheep, meat byproducts''; and ``Walnut'' from the table
in paragraph (a)(1);
ii. By alphabetically adding the entries for ``Almond, hulls'';
``Cattle, meat byproducts''; ``Fruit, stone, group 12, except
cherries''; ``Goat, meat byproducts''; ``Grass, fodder, forage, and
hay, group 17''; ``Hog, meat byproducts''; ``Horse, meat byproducts'';
``Nut, tree, group 14''; ``Pepper''; ``Pistachio''; and ``Sheep, meat
byproducts'' to the table in paragraph (a)(2); and
iii. By removing the text from paragraph (c) and reserving
paragraph (c) with the heading.
The additions and revisions read as follows:

Sec. 180.377 Diflubenzuron; tolerances for residues.

(a) General. (1) * * *
(2) * * *

------------------------------------------------------------------------
Commodity Parts per million
------------------------------------------------------------------------
Almond , hulls 6.0
Cattle, meat byproducts 0.15
Fruit, stone, group 12, except cherries 0.07
Goat, meat byproducts 0.15
Grass, forage, fodder, and hay, group 17 6.0
Hog, meat byproducts 0.15
Horse, meat byproducts 0.15
Nut, tree, group 14 0.06
* * * * *
Pepper 1.0
Pistachio 0.06
* * * * *
Sheep, meat byproducts 0.15
------------------------------------------------------------------------

* * * * *

[FR Doc. 02-23818 Filed 9-18-02; 8:45 am]
BILLING CODE 6560-50-S