[Federal Register Volume 64, Number 188 (Wednesday, September 29, 1999)]
[Rules and Regulations]
[Pages 52450-52457]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-25312]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-300921; FRL-6382-1]
RIN 2070-AB78
Diflubenzuron; Pesticide Tolerances for Emergency Exemptions
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes a time-limited tolerance for
residues of diflubenzuron (N-[[4-
[[Page 52451]]
chlorophenyl)amino]-carbonyl]-2,6-difluorobenzamide) and its
metabolites PCA (4-chloroaniline) and CPU (4-chlorophenylurea),
expressed as parent compound in or on pears. This action is in response
to EPA's granting of an emergency exemption under section 18 of the
Federal Insecticide, Fungicide, and Rodenticide Act authorizing use of
the pesticide on pears. This regulation establishes a maximum
permissible level for residues of diflubenzuron in this food commodity.
The tolerance will expire and is revoked on March 31, 2001.
DATES: This regulation is effective September 29, 1999. Objections and
requests for hearings, identified by docket control number OPP-300921,
must be received by EPA on or before November 29, 1999.
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 VII. of the ``SUPPLEMENTARY
INFORMATION'' section. To ensure proper receipt by EPA, your objections
and hearing requests must identify docket control number OPP-300921 in
the subject line on the first page of your response.
FOR FURTHER INFORMATION CONTACT: By mail:Andrea Beard, Registration
Division (7505C), Office of Pesticide Programs, Environmental
Protection Agency, 401 M St., SW., Washington, DC 20460; telephone
number: (703)308-9356; and e-mail address: [email protected].
SUPPLEMENTARY INFORMATION:
I. General Information
A. Does this Action Apply to Me?
You may be potentially affected by this action if you are an
agricultural producer, food manufacturer, or pesticide manufacturer.
Potentially affected categories and entities may include, but are not
limited to:
------------------------------------------------------------------------
Examples of
Categories NAICS Potentially
Affected Entities
------------------------------------------------------------------------
Industry 111 Crop production
112 Animal production
311 Food manufacturing
32532 Pesticide
manufacturing
------------------------------------------------------------------------
This listing is not intended to be exhaustive, but rather provides
a guide for readers regarding entities likely to be affected by this
action. Other types of entities not listed in the table could also be
affected. The North American Industrial Classification System (NAICS)
codes have been provided to assist you and others in determining
whether or not this action might apply to certain entities. If you have
questions regarding the applicability of this action to a particular
entity, consult the person listed in the ``FOR FURTHER INFORMATION
CONTACT'' section.
B. How Can I Get Additional Information, Including Copies of This
Document and Other Related Documents?
1. Electronically.You may obtain electronic copies of this
document, and certain other related documents that might be available
electronically, from the EPA Internet Home Page at http://www.epa.gov/.
To access this document, on the Home Page select ``Laws and
Regulations'' and then look up the entry for this document under the
``Federal Register--Environmental Documents.'' You can also go directly
to the Federal Register listings at http://www.epa.gov/fedrgstr/.
2. In person. The Agency has established an official record for
this action under docket control number OPP-300921. The official record
consists of the documents specifically referenced in this action, and
other information related to this action, including any information
claimed as Confidential Business Information (CBI). This official
record includes the documents that are physically located in the
docket, as well as the documents that are referenced in those
documents. The public version of the official record does not include
any information claimed as CBI. The public version of the official
record, which includes printed, paper versions of any electronic
comments submitted during an applicable comment period is available for
inspection in the Public Information and Records Integrity Branch
(PIRIB), Rm. 119, Crystal Mall 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
EPA, on its own initiative, in accordance with sections 408 (l)(6)
of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a, is
establishing a tolerance for residues of the insecticide diflubenzuron
and its metabolites PCA and CPU, expressed as parent compound, in or on
pears at 0.5 part per million (ppm). This tolerance will expire and is
revoked on March 31, 2001. EPA will publish a document in the Federal
Register to remove the revoked tolerance from the Code of Federal
Regulations.
Section 408(l)(6) of the FFDCA requires EPA to establish a time-
limited tolerance or exemption from the requirement for a tolerance for
pesticide chemical residues in food that will result from the use of a
pesticide under an emergency exemption granted by EPA under section 18
of FIFRA. Such tolerances can be established without providing notice
or period for public comment. EPA does not intend for its actions on
section 18 related tolerances to set binding precedents for the
application of section 408 and the new safety standard to other
tolerances and exemptions.
Section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a
tolerance (the legal limit for a pesticide chemical residue in or on a
food) only if EPA determines that the tolerance is ``safe.'' Section
408(b)(2)(A)(ii) defines ``safe'' to mean that ``there is a reasonable
certainty that no harm will result from aggregate exposure to the
pesticide chemical residue, including all anticipated dietary exposures
and all other exposures for which there is reliable information.'' This
includes exposure through drinking water and in residential settings,
but does not include occupational exposure. Section 408(b)(2)(C)
requires EPA to give special consideration to exposure of infants and
children to the pesticide chemical residue in establishing a tolerance
and to ``ensure that there is a reasonable certainty that no harm will
result to infants and children from aggregate exposure to the pesticide
chemical residue. . . .''
Section 18 of the Federal Insecticide, Fungicide, and Rodenticide
Act (FIFRA) authorizes EPA to exempt any Federal or State agency from
any provision of FIFRA, if EPA determines that ``emergency conditions
exist which require such exemption.'' This provision was not amended by
Food Quality Protection Act (FQPA). EPA has established regulations
governing such emergency exemptions in 40 CFR part 166.
III. Emergency Exemption for Diflubenzuron on Pears and FFDCA
Tolerances
The Oregon and Washington Departments of Agriculture requested use
of diflubenzuron on pears, for control of pear psylla, which had
developed resistance to currently available pesticides, and was
expected to cause significant economic loss if not adequately
controlled. EPA has authorized under FIFRA section 18 the use of
diflubenzuron on pears for
[[Page 52452]]
control of pear psylla in Oregon and Washington. After having reviewed
the submission, EPA concurs that emergency conditions exist for these
states.
As part of its assessment of this emergency exemption, EPA assessed
the potential risks presented by residues of diflubenzuron in or on
pears. In doing so, EPA considered the safety standard in FFDCA section
408(b)(2), and EPA decided that the necessary tolerance under FFDCA
section 408(l)(6) would be consistent with the safety standard and with
FIFRA section 18. Consistent with the need to move quickly on the
emergency exemption in order to address an urgent non-routine situation
and to ensure that the resulting food is safe and lawful, EPA is
issuing this tolerance without notice and opportunity for public
comment as provided in section 408(l)(6). Although this tolerance will
expire and is revoked on March 31, 2001, under FFDCA section 408(l)(5),
residues of the pesticide not in excess of the amounts specified in the
tolerance remaining in or on pears after that date will not be
unlawful, provided the pesticide is applied in a manner that was lawful
under FIFRA, and the residues do not exceed a level that was authorized
by this tolerance at the time of that application. EPA will take action
to revoke this tolerance earlier if any experience with, scientific
data on, or other relevant information on this pesticide indicate that
the residues are not safe.
Because this tolerance is being approved under emergency conditions
EPA has not made any decisions about whether diflubenzuron meets EPA's
registration requirements for use on pears or whether a permanent
tolerance for this use would be appropriate. Under these circumstances,
EPA does not believe that this tolerance serves as a basis for
registration of diflubenzuron by a State for special local needs under
FIFRA section 24(c). Nor does this tolerance serve as the basis for any
State other than Oregon and Washington to use this pesticide on this
crop under section 18 of FIFRA without following all provisions of
EPA's regulations implementing section 18 as identified in 40 CFR part
166. For additional information regarding the emergency exemption for
diflubenzuron, contact the Agency's Registration Division at the
address provided under the ``ADDRESSES'' section.
IV. Aggregate Risk Assessment and Determination of Safety
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) .
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
diflubenzuron and to make a determination on aggregate exposure,
consistent with section 408(b)(2), for a time-limited tolerance for
residues of diflubenzuron and its metabolites PCA and CPU, expressed as
parent compound on pears at 0.5 ppm. EPA's assessment of the dietary
exposures and risks associated with establishing the tolerance follows.
A. Toxicological Profile
EPA has evaluated the available toxicity data and considered its
validity, completeness, and reliability as well as the relationship of
the results of the studies to human risk. EPA has also considered
available information concerning the variability of the sensitivities
of major identifiable subgroups of consumers, including infants and
children. The nature of the toxic effects caused by diflubenzuron are
discussed in this unit.
B. Toxicological Endpoint
1. Acute toxicity. A risk assessment for acute (1-day) dietary
exposure is not necessary. One day single dose oral studies in rats and
mice indicated only marginal effects on methemoglobin levels at a dose
level of 10,000 milligrams/kilogram/day (mg/kg/day).
2. Short- and intermediate-term toxicity. The toxicological
endpoint for short-term occupational or residential exposure (1-7 days)
is sulfhemoglobinemia observed in the 14-day subchronic oral study in
mice dosed with technical grade diflubenzuron. The no observed adverse
effect level (NOAEL) in this study was 40 mg/kg/day, and the lowest
observed adverse effect level (LOAEL) was 200 mg/kg/day.
The toxicological endpoint for intermediate-term occupational or
residential exposure (1 week to several months) is methemoglobinemia
observed in the 13-week subchronic feeding study in dogs. For the
purpose of risk assessments, the NOAEL of 1.64 mg/kg/day in this study
should be rounded up to 2 mg/kg/day, so as to be consistent with the
NOAEL of 2 mg/kg/day in the chronic study used to calculate the
Reference Dose (RfD). The LOAEL in this study was 6.24 mg/kg/day. Since
an oral NOAEL was selected for a dermal endpoint, a dermal absorption
factor of 0.5% should be used for this risk assessment when converting
dermal exposure to oral equivalents. Therefore, the dermal equivalent
dose producing a NOAEL by the oral route is calculated to be 400 mg/kg/
day (2.0 mg/kg/day divided by 0.005 = 400 mg/kg/day).
3. Chronic toxicity. EPA has established the RfD for diflubenzuron
at 0.02 mg/kg/day, based on the NOAEL of 2.0 mg/kg/day from the 52-
week chronic oral study in dogs. Increases in methemoglobin and
sulfhemoglobin were observed at the next higher dose level (LOAEL) of
10.0 mg/kg/day. An uncertainty factor of 100 was applied to account for
the interspecies extrapolation and intraspecies variability.
Diflubenzuron has been reviewed by the FAO/WHO joint committee on
pesticide residues and an Acceptable Daily Intake (ADI) of 0.02 mg/kg/
day was established in 1985. The ADI was based upon the 1- year oral
toxicity study in dogs with a NOAEL of 2.0 mg/kg/day, with a safety
factor of 100 applied to account for inter- and intra- species
variability.
4. Carcinogenicity. Based on the available evidence, which included
adequate carcinogenicity studies in rats and mice, and a battery of
negative mutagenicity studies, diflubenzuron per se has been classified
as Group E (evidence of non- carcinogenicity for humans). However, p-
chloroaniline (PCA), a metabolite of diflubenzuron, was classified as a
Group B2 carcinogen (probable human carcinogen). The classification for
PCA was based on the results of a National Toxicology Program (N.T.P.)
study reported in July 1989, in which PCA-HCL was administered by
gavage to rats and mice for 2 years. In rats, clearly increased
incidences of uncommon sarcomas (fibrosarcomas, hemangiosarcomas, and/
or osteosarcomas) of the spleen were observed in males. In females, two
additional sarcomas of the spleen were also found. Pheochromocytomas of
the adrenal gland may also have been associated with the test material
in male and female rats. In mice, increased incidences of
hepatocellular neoplasms in the liver and of hemangiosarcomas in the
spleen and/or liver were observed in males. In females, no evidence of
carcinogenic activity was observed. The results of several mutagenicity
studies on PCA were also included in the same N.T.P. Report. PCA was
mutagenic in Salmonella strains TA98 and TA100 with metabolic
activation. Gene
[[Page 52453]]
mutations were induced by PCA in cultured mouse lymphoma cells with and
without metabolic activation. In cultured Chinese Hamster Ovary (CHO)
cells, treatment with PCA produced significant increases in sister
chromatic exchanges (SCEs) with and without metabolic activation.
Chromosomal aberrations were also significantly increased in CHO cells
in the presence of metabolic activation.
For the purpose of calculating dietary risk assessments, the
following procedure was used:
i. P-chlorophenylurea (CPU) and p-chloroacetanilide (PCAA),
additional metabolites of diflubenzuron that are closely related to PCA
and for which there are no adequate carcinogenicity data available,
should be considered to be potentially carcinogenic and to have the
same carcinogenic potency (Q1*) as PCA.
ii. The sum of PCA, CPU, and PCAA residues in ingested food should
be used to estimate the dietary exposure of humans to the carcinogenic
metabolites of diflubenzuron.
iii. In addition to ingested residues of these three metabolites,
amounts of PCA, CPU, and/or PCAA formed in vivo following ingestion of
diflubenzuron should also be included when estimating the total
exposure of humans to the carcinogenic metabolites of diflubenzuron.
The in vivo conversion of ingested diflubenzuron to PCA and/or CPU was
estimated to be 2.0%, based on data in the rat metabolism study.
The Q1* (estimated unit risk) for PCA, based upon spleen
sarcoma rates in male rats, was calculated to be 6.38 x 10-2
(mg/kg/day)-1 in human equivalents. It has been determined
that PCAA does not occur in animal or plant tissues in significant
amounts.
C. Exposures and Risks
1. From food and feed uses. Tolerances have been established (40
CFR 180.377) for the residues of diflubenzuron per se, in or on citrus,
artichokes, walnuts, mushrooms, cottonseed, soybean, rice, and
associated livestock commodities. Existing tolerances range from 0.05
ppm in/on soybeans, to 6.0 ppm in/on artichokes. Tolerances of 0.05 ppm
have also been established for residues of diflubenzuron in animal
commodities. Risk assessments were conducted by EPA to assess dietary
exposures and risks from diflubenzuron as follows:
i. Acute exposure and risk. Acute dietary risk assessments are
performed for a food-use pesticide if a toxicological study has
indicated the possibility of an effect of concern occurring as a result
of a 1-day or single exposure. One day single dose oral studies in rats
and mice indicated only marginal effects on methemoglobin levels at a
dose level of 10,000 mg/kg/day. Therefore, this risk assessment is not
needed, as there are no significant acute effects observed.
ii. Chronic exposure and risk. For conducting the chronic dietary
risk assessment, refined residue estimates were used for all
commodities except for pears. Percent of crop treated figures were also
used for certain commodities. The percent of RfD utilized for Non-
Nursing Infants <1 Yr. Old (the most highly exposed subgroup) was 6.1%.
For Nursing Infants, this figure was 2.2%, and for all other population
subgroups, including the overall U.S. Population, the ARC utilized less
than 1% of the RfD.
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 crop treated (PCT) for assessing chronic dietary risk
only if the Agency can make the following findings: 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; that the exposure estimate does not underestimate exposure for
any significant subpopulation group; and 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 PCT as required by section 408(b)(2)(F), EPA may require registrants
to submit data on PCT.
The Agency used PCT information as follows: 1% for grass/rangeland;
3% for cottonseed; 8% for grapefruit; 3.1% for mushrooms; 2% for
oranges; 4% for tangerines; 1% for soybean; and 5% for cattle bolus.
Other commodities were assumed to be 100% treated.
The Agency believes that the three conditions, discussed in section
408 (b)(2)(F) in this unit concerning the Agency's responsibilities in
assessing chronic dietary risk findings, have been met. The PCT
estimates are derived from Federal and private market survey data,
which are reliable and have a valid basis. Typically, a range of
estimates are supplied and the upper end of this range is assumed for
the exposure assessment. By using this upper end estimate of the PCT,
the Agency is reasonably certain that the percentage of the food
treated is not likely to be underestimated. The 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. From drinking water. The Agency currently lacks sufficient
water- related exposure data to complete a comprehensive drinking water
exposure analysis and risk assessment for diflubenzuron. Because the
Agency does not have comprehensive and reliable monitoring data,
drinking water concentration estimates must be made by reliance on some
sort of simulation or modeling. To date, there are no validated
modeling approaches for reliably predicting pesticide levels in
drinking water. The Agency is currently relying on the models GENEEC
and PRZM/EXAMS for surface water, which are used to produce estimates
of pesticide concentrations in a farm pond; and SCI-GROW, which
predicts pesticide concentrations in groundwater. None of these models
include consideration of the impact that processing of raw water, for
distribution as drinking water, would likely have on the removal of
pesticides from the source water. The primary use of these models by
the Agency at this stage is to provide a coarse screen for sorting out
pesticides for which it is highly unlikely
[[Page 52454]]
that drinking water concentrations would ever exceed human health
levels of concern.
In the absence of monitoring data for pesticides, 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 for a pesticide's
concentration in drinking water in light of total aggregate exposure to
a pesticide in food, drinking water, and residential uses. A DWLOC will
vary depending on the toxic endpoint, with drinking water consumption,
and body weights. Different populations will have different DWLOCs.
DWLOCs are used in the risk assessment process as a surrogate measure
of potential exposure associated with pesticide exposure through
drinking water. DWLOC values are not regulatory standards for drinking
water. Since DWLOCs address total aggregate exposure to diflubenzuron
they are further discussed in the aggregate risk sections below.
3. From non-dietary exposure. Diflubenzuron is a restricted use
pesticide and therefore not available for use by homeowners, although
it is possible that non- agricultural uses of diflubenzuron may expose
people in residential locations. However, based on the low dermal
absorption rate (0.5%), and the extremely low dermal and inhalation
toxicity, these uses are expected to result in insignificant risks.
4. Cumulative exposure to substances with common mechanism of
toxicity. Section 408(b)(2)(D)(v) requires that, when considering
whether to establish, modify, or revoke a tolerance, the Agency
consider ``available information'' concerning the cumulative effects of
a particular pesticide's residues and ``other substances that have a
common mechanism of toxicity.''
Diflubenzuron is structurally similar to other substituted
benzoylurea insecticides including triflumuron and flucycloxuron.
However, 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 more 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. Aggregate Risks and Determination of Safety for U.S. Population
1. Acute risk. Since one day single dose oral studies in rats and
mice indicated only marginal effects, this risk assessment is not
needed, as there were no significant acute effects observed.
2. Chronic risk. Using the ARC exposure assumptions described in
this unit, EPA has concluded that aggregate exposure to diflubenzuron
from food will utilize <1 of the RfD for the U.S. population. The major
identifiable subgroup with the highest aggregate exposure is Non-
nursing infants, <1 year old, for which 6.1% of the RfD was utilized.
EPA generally has no concern for exposures below 100% of the RfD
because the RfD represents the level at or below which daily aggregate
dietary exposure over a lifetime will not pose appreciable risks to
human health. The Agency does not have monitoring data available to
perform a quantitative drinking water risk assessment for diflubenzuron
at this time. Based on PRZM/EXAMS modeling, the average annual mean
concentration of diflubenzuron in surface water sources is not expected
to exceed 0.05 ppb. Estimated concentrations of CPU in surface water
sources is not expected to exceed 0.73 ppb. These values reflect the
maximum concentrations for any of the crops treated with diflubenzuron
(including pears). The DWLOCs for chronic (non-cancer) exposure to
diflubenzuron in drinking water for the U.S. population and Non Nursing
Infants (< 1 yr. old), and Females (13+ yrs. old/nursing) are 700, 190,
and 600 ppb, respectively. The estimated maximum concentration of
diflubenzuron in surface and ground water (0.05 ppb) is lower than the
DWLOCs as a contribution to chronic aggregate exposure. Therefore, EPA
concludes that residues of diflubenzuron and its metabolites in
drinking water would not result in an unacceptable estimate of chronic,
non- cancer risk. Despite the potential for exposure to diflubenzuron
in drinking water and from non-dietary, non-occupational exposure, EPA
does not expect the aggregate exposure to exceed 100% of the RfD.
3. Short- and intermediate-term risk. Short- and intermediate-term
aggregate exposure takes into account chronic dietary food and water
(considered to be a background exposure level) plus indoor and outdoor
residential exposure.
As stated earlier, although residential exposure has been
considered possible from, for example, area-wide gypsy moth or mosquito
control, this contribution is anticipated to be negligible. Thus, it
was determined that this risk assessment is not necessary.
4. Aggregate cancer risk for U.S. population. A cancer risk
assessment was conducted for the metabolites of diflubenzuron, PCA and
CPU. As a conservative measure, EPA assumes that PCA/CPU occupied 2% of
diflubenzuron tolerance levels, based upon metabolism studies. Based
upon the ARC estimates described above, the cancer risk for the overall
U.S. population from dietary (food only) was calculated to be 5 x
10-7, which does not exceed EPA's levels of concern. The
DWLOC for cancer risk for the U.S. population is 0.26 ppb. Estimated
drinking water concentrations from PCA/CPU (0.73 ppb) are greater than
the DWLOC of 0.26, for cancer risk. However, EPA believes these
estimates are significantly overstated for several reasons. The PRZM/
EXAMS model used to derive these estimates was designed for ecological
risk assessments, and uses a scenario of a body of water approximating
the size of a 2.5 acre pond. This tends to overstate chronic drinking
water exposure levels for the following reasons. First, surface water
source drinking water generally comes from bodies of water that are
substantially larger. Second, the scenario assumes that the whole basin
receives an application of the pesticide, but in virtually all cases,
basins used for drinking water will contain a substantial portion of
the area that does not receive pesticide application. Third, there is
often at least some flow or turnover of the water, so the persistence
of the pesticide near the drinking water facility is usually
overestimated. Fourth, even assuming that the reservoir is directly
adjacent to an agricultural field, the field may not be used to grow a
crop on which the pesticide in question is registered for use. Fifth,
the PRZM/EXAMS scenario does not take into account reductions in
residue-loading due to applications less than the maximum application
rate or no treatment of the crop at all. Considering these
uncertainties associated with the modeled water estimates noted above,
and the fact that the estimated concentrations are within close range
of the DWLOCs, EPA concludes with reasonable certainty that residues of
diflubenzuron in drinking water will
[[Page 52455]]
not contribute significantly to the aggregate cancer human health risk.
5. Determination of safety. Based on these risk assessments, EPA
concludes that there is a reasonable certainty that no harm will result
from aggregate exposure to diflubenzuron residues.
E. Aggregate Risks and Determination of Safety for Infants and Children
1. Safety factor for infants and children-- i. In general. In
assessing the potential for additional sensitivity of infants and
children to residues of diflubenzuron, EPA considered data from
developmental toxicity studies in the rat and rabbit and a 2-generation
reproduction study in the rat. The developmental toxicity studies are
designed to evaluate adverse effects on the developing organism
resulting from maternal pesticide exposure during gestation.
Reproduction studies provide information relating to effects from
exposure to the pesticide on the reproductive capability of mating
animals and data on systemic toxicity.
FFDCA section 408 provides that EPA shall apply an additional
tenfold margin of safety for infants and children in the case of
threshold effects to account for pre- and post-natal toxicity and the
completeness of the data base unless EPA determines that a different
margin of safety will be safe for infants and children. Margins of
safety are incorporated into EPA risk assessments either directly
through use of a margin of exposure (MOE) analysis or through using
uncertainty (safety) factors in calculating a dose level that poses no
appreciable risk to humans. EPA believes that reliable data support
using the standard MOE and uncertainty factor (usually 100 for combined
inter- and intra-species variability) and not the additional tenfold
MOE/uncertainty factor when EPA has a complete data base under existing
guidelines and when the severity of the effect in infants or children
or the potency or unusual toxic properties of a compound do not raise
concerns regarding the adequacy of the standard MOE/safety factor.
ii. Developmental toxicity studies. In the developmental study in
rats, the maternal (systemic) and the developmental (fetal) NOAEL were
both 1,000 mg/kg/day. No LOAELs were achieved, as no maternal or
developmental toxicity was observed.
In the developmental toxicity study in rabbits, both the maternal
(systemic) and the developmental (fetal) NOAELs were both 1,000 mg/kg/
day. As with the rat study, mentioned above, no LOAELs were achieved,
as no maternal or developmental toxicity was observed.
iii. Reproductive toxicity study. In the 2-generation reproductive
toxicity study in rats, the parental (systemic) NOAEL was considered to
be less than 36 mg/kg/day for males, and less than 42 mg/kg/day for
females based on hematological effects at all dose levels tested. For
offspring effects, the NOAEL was equal to 427 mg/kg/day, and the LOAEL
was equal to 4,254 mg/kg/day, based on statistically significant
decreases in F-1 pup weight on days 4, 8, and 21 of lactation.
iv. Pre- and post-natal sensitivity. The toxicological database for
evaluating pre- and post-natal toxicity for diflubenzuron is completed
with respect to current data requirements. There are no pre- or post-
natal toxicity concerns for infants and children, based upon the result
of the developmental and reproductive studies mentioned above.
v. Conclusion. The OPP FQPA Safety Factor Committee recommended
that the 10X factor for increased susceptibility of infants and
children be reduced to 1X, for diflubenzuron. This decision was based
on the determination that there was no indication of increased
susceptibility of rats or rabbits to in utero and/or postnatal exposure
to diflubenzuron, and because exposure assessments do not indicate a
concern for potential risk to infants and children. There is a complete
toxicity database for diflubenzuron and exposure data is complete or is
estimated based on data that reasonably accounts for potential
exposures.
2. Acute risk. Since one day single dose oral studies in rats and
mice indicated only marginal effects, this risk assessment is not
needed, as there are no significant acute effects observed.
3. Chronic risk. Using the exposure assumptions described in this
unit, EPA has concluded that aggregate exposure to diflubenzuron from
food will utilize 6.1% of the RfD for Non-Nursing Infants < 1 year old,
the most highly exposed infant/children population subgroup. EPA
generally has no concern for exposures below 100% of the RfD because
the RfD represents the level at or below which daily aggregate dietary
exposure over a lifetime will not pose appreciable risks to human
health. Despite the potential for exposure to diflubenzuron in drinking
water and from non-dietary, non-occupational exposure, EPA does not
expect the aggregate exposure to exceed 100% of the RfD.
4. Short- or intermediate-term risk. As stated earlier, although
residential exposure has been considered possible from, for example,
area-wide gypsy moth or mosquito control, this contribution is
anticipated to be negligible. Thus, it was determined that this risk
assessment is not necessary.
5. Determination of safety. Based on these risk assessments, EPA
concludes that there is a reasonable certainty that no harm will result
to infants and children from aggregate exposure to diflubenzuron
residues.
V. Other Considerations
A. Metabolism in Plants and Animals
The nature of the residue in plants and animals is adequately
understood. The residue of concern is diflubenzuron and its metabolites
p-chloroaniline (PCA) and p- chlorophenylurea (CPU), expressed as the
parent compound.
B. Analytical Enforcement Methodology
Adequate methodology for the analysis of diflubenzuron is available
to enforce the tolerance expression. Three analytical methods for
diflubenzuron are published in PAM, Vol. II as Methods I, II, and III.
All three methods have undergone successful Agency validations and are
acceptable for enforcement purposes.
C. Magnitude of Residues
Residues of diflubenzuron and its metabolites are not expected to
exceed 0.5 ppm in/on pears as a result of this use.
D. International Residue Limits
There is a Codex maximum residue limit (MRL) for pears at 1 mg/kg,
a MRL for Mexico at 1.0 mg/kg, and no limits set for Canada for pears.
This tolerance is to be set at a lower level than the MRLs. This is a
time-limited tolerance, established solely in support of this section
18 use. In considering permanent tolerances for pears in the future,
the Agency will take these circumstances into account.
E. Rotational Crop Restrictions
Available data for diflubenzuron indicate that tolerances for
residues in rotational crops will not be required, provided the label
specifies a restriction for the planting of rotational crops of at
least 30 days.
VI. Conclusion
Therefore, the tolerance is established for combined residues of
diflubenzuron and its metabolites PCA and CPU, expressed as parent
compound in pears at 0.5 ppm.
VII. 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
[[Page 52456]]
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-300921 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
29, 1999.
1. Filing the request. Your objection must specify the specific
provisions in the regulation that you object to, and the grounds for
the objections (40 CFR 178.25). If a hearing is requested, the
objections must include a statement of the factual issues(s) on which a
hearing is requested, the requestor's contentions on such issues, and a
summary of any evidence relied upon by the objector (40 CFR 178.27).
Information submitted in connection with an objection or hearing
request may be claimed confidential by marking any part or all of that
information as CBI. Information so marked will not be disclosed except
in accordance with procedures set forth in 40 CFR part 2. A copy of the
information that does not contain CBI must be submitted for inclusion
in the public record. Information not marked confidential may be
disclosed publicly by EPA without prior notice.
Mail your written request to: Office of the Hearing Clerk (1900),
Environmental Protection Agency, 401 M St., SW., Washington, DC 20460.
You may also deliver your request to the Office of the Hearing Clerk in
Room M3708, Waterside Mall, 401 M St., SW., Washington, DC 20460. The
Office of the Hearing Clerk is open from 8 a.m. to 4 p.m., Monday
through Friday, excluding legal holidays. The telephone number for the
Office of the Hearing Clerk is (202) 260-4865.
2. Tolerance fee payment. If you file an objection or request a
hearing, you must also pay the fee prescribed by 40 CFR 180.33(i) or
request a waiver of that fee pursuant to 40 CFR 180.33(m). You must
mail the fee to: EPA Headquarters Accounting Operations Branch, Office
of Pesticide Programs, P.O. Box 360277M, Pittsburgh, PA 15251. Please
identify the fee submission be 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.'' (cite). 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, 401 M St., SW., 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, 401 M St., SW.,
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 VII.A. of
this preamble, 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. of this preamble. Mail your copies, identified by the docket
number OPP-300921, to: Public Information and Records Integrity Branch,
Information Resources and Services Division (7502C), Office of
Pesticide Programs, Environmental Protection Agency, 401 M St., SW.,
Washington, DC 20460. In person or by courier, bring a copy to the
location of the PIRIB described in Unit I.B.2. of this preamble. You
may also send an electronic copy of your request via e-mail to: opp-
[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 5.1/6.1 file format or ASCII file format. Do not include
any CBI in your electronic copy. You may also submit an electronic copy
of your request at many Federal Depository Libraries.
B. When Will the Agency Grant a Request for a Hearing?
A request for a hearing will be granted if the Administrator
determines that the material submitted shows the following: There is a
genuine and substantial issue of fact; there is a reasonable
possibility that available evidence identified by the requestor would,
if established resolve one or more of such issues in favor of the
requestor, taking into account uncontested claims or facts to the
contrary; and resolution of the factual issues(s) in the manner sought
by the requestor would be adequate to justify the action requested (40
CFR 178.32).
VIII. Regulatory Assessment Requirements
This final rule establishes a tolerance under section 408 of the
FFDCA. The Office of Management and Budget (OMB) has exempted these
types of actions from review under Executive Order 12866, entitled
Regulatory Planning and Review (58 FR 51735, October 4, 1993). This
final rule does not contain any information collections subject to OMB
approval under the Paperwork Reduction Act (PRA), 44 U.S.C. 3501 et
seq., or impose any enforceable duty or contain any unfunded mandate as
described under Title II of the Unfunded Mandates Reform Act of 1995
(UMRA) (Public Law 104-4). Nor does it require prior consultation with
State, local, and tribal government officials as specified by Executive
Order 12875, entitled Enhancing the Intergovernmental Partnership (58
FR 58093, October 28, 1993) and Executive Order 13084, entitled
Consultation and Coordination with Indian Tribal Governments (63 FR
27655, May 19,1998), or special consideration of environmental justice
related issues 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 require OMB review in
accordance with Executive Order 13045, entitled Protection of Children
from Environmental Health Risks and Safety Risks (62 FR 19885, April
23, 1997). 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 12612, entitled Federalism (52 FR 41685, October 30,
1987). This action directly regulates growers, food processors, food
handlers and food retailers, not States. This
[[Page 52457]]
action does not alter the relationships or distribution of power and
responsibilities established by Congress in the preemption provisions
of the FFDCA, 21 U.S.C. 346a(n)(4). 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). In addition, since
tolerances and exemptions that are established under FFDCA section
408(l)(6), 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.
IX. 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 rule in the Federal Register. This rule is not a
``major rule'' as defined by 5 U.S.C. 804(2).
List of Subjects in 40 CFR Part 180
Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and
recordkeeping requirements.
Dated: September 14, 1999 .
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 371.
2. In Sec. 180.377, by adding text to paragraph (b) to read as
follows:
Sec. 180.377 Diflubenzuron; tolerances for residues.
* * * * *
(b) Section 18 emergency exemptions. Time-limited tolerances are
established for residues of diflubenzuron and its metabolites, PCA (4-
chloroaniline) and CPU (4-chlorophenylurea), expressed as the parent
diflubenzuron, in connection with use of this pesticide under a section
18 emergency exemption granted by EPA. The tolerances will expire on
the dates specified in the following table.
------------------------------------------------------------------------
Expiration/
Commodity Parts per million revocation date
------------------------------------------------------------------------
Pears........................... 0.5 3/31/00
------------------------------------------------------------------------
* * * * *
[FR Doc. 99-25312 Filed 9-28-99; 8:45 am]
BILLING CODE 6560-50-F