[Federal Register Volume 67, Number 182 (Thursday, September 19, 2002)]
[Rules and Regulations]
[Pages 59006-59017]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-23818]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-2002-0224; FRL-7200-4]


Diflubenzuron; Pesticide Tolerances

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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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: [email protected].

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

    You may be affected by this action if you are an agricultural 
producer, food manufacturer, or pesticide manufacturer. Potentially 
affected categories and entities may include, but are not limited to:

------------------------------------------------------------------------
                                                          Examples of
           Categories                 NAICS 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 (MOEcancer = 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 [email protected], 
or by mailing a request for information to Mr. Tompkins at Registration 
Division (7505C), Office of Pesticide Programs, Environmental 
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460.
    If you would like to request a waiver of the tolerance objection 
fees, you must mail your request for such a waiver to: James Hollins, 
Information Resources and Services Division (7502C), Office of 
Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania 
Ave., NW., Washington, DC 20460.
    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: [email protected]. Please use an ASCII file 
format and avoid the use of special characters and any form of 
encryption. Copies of electronic objections and hearing requests will 
also be accepted on disks in WordPerfect 6.1/8.0 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