[Federal Register Volume 76, Number 41 (Wednesday, March 2, 2011)]
[Rules and Regulations]
[Pages 11344-11350]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-4370]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[EPA-HQ-OPP-2009-0823; FRL-8864-9]
Difenoconazole; Pesticide Tolerances
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes tolerances for residues of
difenoconazole in or on mango and wax jambu. Syngenta Crop Protection,
Incorporated requested these tolerances under the Federal Food, Drug,
and Cosmetic Act (FFDCA).
DATES: This regulation is effective March 2, 2011. Objections and
requests for hearings must be received on or before May 2, 2011, and
must be filed in accordance with the instructions provided in 40 CFR
part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).
ADDRESSES: EPA has established a docket for this action under docket
identification (ID) number EPA-HQ-OPP-2009-0823. All documents in the
docket are listed in the docket index available at http://www.regulations.gov. Although listed in the index, some information is
not publicly available, e.g., Confidential Business Information (CBI)
or other information whose disclosure is restricted by statute. Certain
other material, such as copyrighted material, is not placed on the
Internet and will be publicly available only in hard copy form.
Publicly available docket materials are available in the electronic
docket at http://www.regulations.gov, or, if only available in hard
copy, at the OPP Regulatory Public Docket in Rm. S-4400, One Potomac
Yard (South Bldg.), 2777 S. Crystal Dr., Arlington, VA. The Docket
Facility is open from 8:30 a.m. to 4 p.m., Monday through Friday,
excluding legal holidays. The Docket Facility telephone number is (703)
305-5805.
FOR FURTHER INFORMATION CONTACT: Tony Kish, Registration Division,
Office of Pesticide Programs, Environmental Protection Agency, 1200
Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone number:
(703) 308-9443; 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 entities may include, but are not limited to those
engaged in the following activities:
Crop production (NAICS code 111).
Animal production (NAICS code 112).
Food manufacturing (NAICS code 311).
Pesticide manufacturing (NAICS code 32532).
This listing is not intended to be exhaustive, but rather to
provide a guide for readers regarding entities likely to be affected by
this action. Other types of entities not listed in this unit could also
be affected. The North American Industrial Classification System
(NAICS) codes have been provided to assist you and others in
determining whether this action might apply to certain entities. If you
have any 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 electronic access to other related information?
You may access a frequently updated electronic version of EPA's
tolerance regulations at 40 CFR part 180 through the Government
Printing Office's e-CFR site at http://www.gpoaccess.gov/ecfr.
C. How can I file an objection or hearing request?
Under FFDCA section 408(g), 21 U.S.C. 346a, any person may file an
objection to any aspect of this regulation and may also request a
hearing on those objections. You must file your objection or request a
hearing on this regulation in accordance with the instructions provided
in 40 CFR part 178. To ensure proper receipt by EPA, you must identify
docket ID number EPA-HQ-OPP-2009-0823 in the subject line on the first
page of your submission. All objections and requests for a hearing must
be in writing, and must be received by the Hearing Clerk on or before
May 2, 2011. Addresses for mail and hand delivery of objections and
hearing requests are provided in 40 CFR 178.25(b).
In addition to filing an objection or hearing request with the
Hearing Clerk as described in 40 CFR part 178, please submit a copy of
the filing that does not contain any CBI for inclusion in the public
docket. Information not marked confidential pursuant to 40 CFR part 2
may be disclosed publicly by EPA without prior notice. Submit a copy of
your non-CBI objection or hearing request, identified by docket ID
number EPA-HQ-OPP-2009-0823, by one of the following methods:
Federal eRulemaking Portal: http://www.regulations.gov.
Follow the on-line instructions for submitting comments.
Mail: Office of Pesticide Programs (OPP) Regulatory Public
Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania
Ave., NW., Washington, DC 20460-0001.
Delivery: OPP Regulatory Public Docket (7502P),
Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South
Bldg.), 2777 S. Crystal Dr., Arlington, VA. Deliveries are only
accepted during the Docket Facility's normal hours of operation (8:30
a.m. to 4 p.m., Monday through Friday, excluding legal holidays).
Special arrangements should be made for deliveries of boxed
information. The Docket Facility telephone number is (703) 305-5805.
II. Summary of Petitioned-For Tolerances
In the Federal Register of January 6, 2010 (75 FR 864) (FRL-8801-
5), EPA issued a notice pursuant to section 408(d)(3) of FFDCA, 21
U.S.C. 346a(d)(3), announcing the filing of a pesticide petition (PP
9E7573) by Syngenta Crop Protection, Inc., P. O. Box 18300, Greensboro,
NC 27419. The petition requested that 40 CFR 180.475 be amended by
establishing tolerances for residues of the fungicide, difenoconazole,
[1-[2-[2-chloro-4-(4-chlorophenoxy)phenyl]-4-methyl-1,3-dioxolan-2-
ylmethyl]-1H-1,2,4-triazole], in or on mango at 0.09 parts per
million(ppm) and waxapple at 1.5 ppm. That notice referenced a summary
of the petition prepared by Syngenta Crop Protection, Inc., the
registrant, which is available in the docket, http://www.regulations.gov.
There were no comments received in response to the notice of
filing.
Based upon review of the data supporting the petition, EPA has
revised the proposed tolerance for mango, fruit from 0.09 ppm to 0.07
ppm to reflect the Agency's recommended tolerance level. Additionally,
EPA corrected commodity definitions from ``mango, fruit'' to ``mango''
and ``waxapple'' to ``wax jambu'' to reflect prescribed terminology.
The reasons for these changes are explained in Unit IV.D.
[[Page 11345]]
III. Aggregate Risk Assessment and Determination of Safety
Section 408(b)(2)(A)(i) of 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) of FFDCA 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) of FFDCA 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, * *
*.''
Consistent with section 408(b)(2)(D) of FFDCA, and the factors
specified in section 408(b)(2)(D) of FFDCA, 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 for difenoconazole including
exposure resulting from the tolerances established by this action.
EPA's assessment of exposures and risks associated with difenoconazole
follows.
A. Toxicological Profile
EPA has evaluated the available toxicity data and considered their
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.
Difenoconazole possesses low acute toxicity by the oral, dermal and
inhalation routes of exposure. It is not considered to be an eye or
skin irritant and is not a dermal sensitizer.
In an acute neurotoxicity study in rats, reduced fore-limb grip
strength was observed on day 1 in males and clinical signs of
neurotoxicity in females at the limit dose of 2,000 milligrams/kilogram
(mg/kg). This effect in males is considered as transient since it was
not observed at later observation points and toxicity in females was
observed only at doses exceeding the limit dose. In a subchronic
neurotoxicity study in rats decreased hind limb strength was observed
only in males, which was considered as nonspecific in nature.
Difenoconazole is not a developmental or reproductive toxicant.
Chronic effects in mice and rat studies are seen as cumulative
decreases in body weight gains.
Difenoconazole is not mutagenic. Evidence for carcinogenicity was
seen only in the mice study, where liver tumors were induced at
excessively high doses for carcinogenicity testing. Liver tumors were
observed in mice at 300 ppm and higher. Based on excessive toxicity
observed at the two highest doses of 2,500 and 4,500 ppm, the absence
of tumors at two lower doses of 10 and 30 ppm, as well as, the absence
of genotoxic effects, the Agency classified difenoconazole as a Group
C, possible human carcinogen with a non-linear margin-of-exposure (MOE)
approach for human risk characterization.
Specific information on the studies received and the nature of the
adverse effects caused by difenoconazole as well as the no-observed-
adverse-effects-level (NOAEL) and the lowest-observed-adverse-effects-
level (LOAEL) from the toxicity studies can be found at http://www.regulations.gov in the document entitled, ``Difenoconazole FQPA
Human Health Risk Assessment to Support the Establishment of Import
Tolerances on Mango and Waxapple (also known as Wax jambu),'' at pages
28-35, dated January 28, 2010, Document No. EPA-HQ-OPP-2009-0823-003.
B. Toxicological Points of Departure/Levels of Concern
Once a pesticide's toxicological profile is determined, EPA
identifies toxicological points of departure (POD) and levels of
concern to use in evaluating the risk posed by human exposure to the
pesticide. For hazards that have a threshold below which there is no
appreciable risk, the toxicological POD is used as the basis for
derivation of reference values for risk assessment. PODs are developed
based on a careful analysis of the doses in each toxicological study to
determine the dose at which no adverse effects are observed (the NOAEL)
and the lowest dose at which adverse effects of concern are identified
(the LOAEL). Uncertainty/safety factors are used in conjunction with
the POD to calculate a safe exposure level--generally referred to as a
population-adjusted dose (PAD) or a reference dose (RfD)--and a safe
margin of exposure (MOE). For non-threshold risks, the Agency assumes
that any amount of exposure will lead to some degree of risk. Thus, the
Agency estimates risk in terms of the probability of an occurrence of
the adverse effect expected in a lifetime. For more information on the
general principles EPA uses in risk characterization and a complete
description of the risk assessment process, see http://www.epa.gov/pesticides/factsheets/riskassess.htm.
A summary of the toxicological endpoints for difenoconazole used
for human risk assessment is shown in the following Table.
Table--Summary of Toxicological Doses and Endpoints for Difenoconazole for Use in Human Health Risk Assessment
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Point of departure and
Exposure/scenario uncertainty/safety RfD, PAD, LOC for risk Study and toxicological
factors assessment effects
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Acute dietary (All populations).... NOAEL = 25 mg/kg/day.. aRfD = 0.25 mg/kg/day. Acute Neurotoxicity Study
UFA = 10x............. aPAD = 0.25 mg/kg/day. in rats LOAEL = 200 mg/kg/
UFH = 10x............. day in males based on
FQPA SF = 1x.......... reduced fore-limb grip
strength in males on day
1.
Chronic dietary (All populations).. NOAEL = 0.96 mg/kg/day cRfD = 0.01 mg/kg/day. Combined chronic toxicity/
UFA = 10x............. cPAD = 0.01 mg/kg/day. carcinogenicity (rat;
UFH = 10x............. dietary) LOAEL = 24.1/32.8
FQPA SF = 1x.......... mg/kg/day (M/F) based on
cumulative decreases in
body-weight gains.
[[Page 11346]]
Dermal short-term (1 to 30 days) Oral NOAEL = 1.25 mg/ Residential LOC for Reproduction and fertility
and intermediate-term (1 to 6 kg/day (dermal MOE = < 100. effects (rat; dietary)
months). absorption factor = Offspring LOAEL = 12.5 mg/
15.3%). kg/day based on reduction
UFA = 10x............. in body weight of F0
UFH = 10x............. females prior to mating,
FQPA SF = 1x.......... gestation and lactation.
Inhalation short-term (1 to 30 Oral NOAEL= 1.25 mg/kg/ Residential LOC for Reproduction and fertility
days) and Intermediate-term day inhalation MOE < 100. effects (rat; dietary)
Inhalation (1 to 6 months). absorption rate = Offspring LOAEL = 12.5 mg/
assumed as 100% kg/day based on reduction
UFA = 10x............. in body weight of F0
UFH = 10x............. females prior to mating,
FQPA SF = 1x.......... gestation and lactation.
----------------------------------------------------------------------------------------------------------------
Cancer (Oral, dermal, inhalation).. Difenoconazole is classified as a Group C, possible human carcinogen with a
non-linear (MOE) approach for human risk characterization.
----------------------------------------------------------------------------------------------------------------
UFA = extrapolation from animal to human (interspecies). UFH = potential variation in sensitivity among members
of the human population (intraspecies). FQPA SF = Food Quality Protection Act Safety Factor. PAD = population
adjusted dose (a = acute, c = chronic). RfD = reference dose. MOE = margin of exposure. LOC = level of
concern.
C. Exposure Assessment
1. Dietary exposure from food and feed uses. In evaluating dietary
exposure to difenoconazole, EPA considered exposure under the
petitioned-for tolerances as well as all existing difenoconazole
tolerances in 40 CFR 180.475. EPA assessed dietary exposures from
difenoconazole in food as follows:
i. Acute exposure. Quantitative acute dietary exposure and 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.
Such effects were identified for difenoconazole. In estimating
acute dietary exposure, EPA used food consumption information from the
United States Department of Agriculture (USDA) 1994-1996 and 1998
Nationwide Continuing Surveys of Food Intake by Individuals (CSFII). As
to residue levels in food, EPA assumed tolerance-level residues, 100
percent crop treated (PCT), and the available empirical or Dietary
Exposure Evaluation Model (DEEMTM) (ver. 7.81) default
processing factors.
ii. Chronic exposure. In conducting the chronic dietary exposure
assessment EPA used the food consumption data from the USDA 1994-1996
and 1998 CSFII. As to residue levels in food, EPA assumed tolerance-
level residues for some commodities, average field trial residues for
the majority of commodities, the available empirical or
DEEMTM (ver. 7.81) default processing factors, and 100 PCT.
iii. Cancer. No evidence of carcinogenicity was seen in rats.
Evidence for carcinogenicity was seen in mice, where liver tumors were
induced at doses which were considered to be excessively high for
carcinogenicity testing. Liver tumors were observed in mice at 300 ppm
and higher; however, based on excessive toxicity observed at the two
highest doses of 2,500 and 4,500 ppm (females terminated after 2 weeks
due to excessive toxicity resulting in moribundity and death), the
absence of tumors at two lower doses of 10 and 30 ppm and the absence
of genotoxic effects, the Agency classified difenoconazole as a Group
C, possible human carcinogen with a non-linear MOE approach for human
risk characterization. A MOE approach in risk assessment was chosen
utilizing the NOAEL of 30 ppm (4.7 and 5.6 mg/kg/day in males and
females, respectively) and the LOAEL of 300 ppm (46 and 58 mg/kg/day in
males and females, respectively) from the mouse study using only those
biological endpoints which were relevant to tumor development (i.e.,
hepatocellular hypertrophy, liver necrosis, fatty changes in the liver
and bile stasis). However, EPA determined that a quantitative cancer
exposure assessment is unnecessary since the NOAEL (4.7 and 5.6 mg/kg/
day in males and females, respectively) to assess cancer risk is higher
than the NOAEL (0.96 and 1.27 mg/kg/day in males and females,
respectively) to assess chronic risks. Therefore, the chronic dietary
risk estimate will be protective of potential cancer risk.
iv. Anticipated residues and percent crop treated (PCT)
information. EPA did not use PCT information in the dietary assessment
of difenoconazole. EPA used anticipated residues including average
field trial residues for the majority of commodities, the available
empirical or DEEMTM (ver. 7.81) default processing factors;
and 100 PCT information in the chronic dietary assessment for
difenoconazole.
Section 408(b)(2)(E) of FFDCA authorizes EPA to use available data
and information on the anticipated residue levels of pesticide residues
in food and the actual levels of pesticide residues that have been
measured in food. If EPA relies on such information, EPA must require,
pursuant to FFDCA section 408(f)(1), 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. For the present action, EPA will issue such data call-ins
as are required by FFDCA section 408(b)(2)(E) and authorized under
FFDCA section 408(f)(1). Data will be required to be submitted no later
than 5 years from the date of issuance of these tolerances.
2. Dietary exposure from drinking water. Although the subject
petition is for import tolerances and therefore does not result in
drinking water exposure, there are existing uses of difenoconazole
registered in the United States. The drinking water assessment was
conducted for parent compound only. The fate and transport database for
difenoconazole were sufficient to conduct the drinking water
assessment.
The Agency used screening level water exposure models in the
dietary exposure analysis and risk assessment for difenoconazole in
drinking water. These simulation models take into
[[Page 11347]]
account data on the physical, chemical, and fate/transport
characteristics of difenoconazole. Further information regarding EPA
drinking water models used in pesticide exposure assessment can be
found at http://www.epa.gov/oppefed1/models/water/index.htm.
Based on the Pesticide Root Zone Model/Exposure Analysis Modeling
System (PRZM/EXAMS) and Screening Concentration in Ground Water (SCI-
GROW) models, the estimated drinking water concentrations (EDWCs) of
difenoconazole for acute exposures are estimated to be 15.8 parts per
billion (ppb) for surface water and 0.0128 ppb for ground water.
Chronic exposures for non-cancer assessments are estimated to be
10.4 ppb for surface water and 0.0128 ppb for ground water.
Modeled estimates of drinking water concentrations were directly
entered into the dietary exposure model.
For acute dietary risk assessment, the water concentration value of
15.8 ppb was used to assess the contribution to drinking water.
For chronic dietary risk assessment, the water concentration of
value 10.4 ppb was used to assess the contribution to drinking water.
3. From non-dietary exposure. The term ``residential exposure'' is
used in this document to refer to non-occupational, non-dietary
exposure (e.g., for lawn and garden pest control, indoor pest control,
termiticides, and flea and tick control on pets).
Difenoconazole is currently registered for the following uses that
could result in residential exposures: Ornamentals. EPA assessed
residential exposure using the following assumptions: Adults may be
exposed to difenoconazole from its currently registered use on
ornamentals. Residential pesticide handlers may be exposed to short-
term duration (1-30 days) only. The dermal and inhalation (short-term)
residential exposure was assessed for ``homeowners'' mixer/loader/
applicator wearing short pants and short-sleeved shirts as well as
shoes plus socks using garden hose-end sprayer, ``pump-up'' compressed
air sprayer, and backpack sprayer.
No post-application exposure is expected. Further information
regarding EPA standard assumptions and generic inputs for residential
exposures may be found at http://www.epa.gov/pesticides/trac/science/trac6a05.pdf.
4. Cumulative effects from substances with a common mechanism of
toxicity. Section 408(b)(2)(D)(v) of FFDCA 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.''
Difenoconazole is a member of the triazole-containing class of
pesticides. Although conazoles act similarly in plants (fungi) by
inhibiting ergosterol biosynthesis, there is not necessarily a
relationship between their pesticidal activity and their mechanism of
toxicity in mammals. Structural similarities do not constitute a common
mechanism of toxicity. Evidence is needed to establish that the
chemicals operate by the same, or essentially the same, sequence of
major biochemical events. In conazoles, however, a variable pattern of
toxicological responses is found. Some are hepatotoxic and
hepatocarcinogenic in mice. Some induce thyroid tumors in rats. Some
induce developmental, reproductive, and neurological effects in
rodents. Furthermore, the conazoles produce a diverse range of
biochemical events including altered cholesterol levels, stress
responses, and altered DNA methylation. It is not clearly understood
whether these biochemical events are directly connected to their
toxicological outcomes. Thus, there is currently no evidence to
indicate that conazoles share common mechanisms of toxicity and EPA is
not following a cumulative risk approach based on a common mechanism of
toxicity for the conazoles. For information regarding EPA's procedures
for cumulating effects from substances found to have a common mechanism
of toxicity, see EPA's Web site at http://www.epa.gov/pesticides/cumulative.
Difenoconazole is a triazole-derived pesticide. This class of
compounds can form the common metabolite 1,2,4-triazole and two
triazole conjugates (triazolylalanine and triazolylacetic acid). To
support existing tolerances and to establish new tolerances for
triazole-derivative pesticides, including difenoconazole, EPA conducted
a human health risk assessment for exposure to 1,2,4-triazole,
triazolylalanine, and triazolylacetic acid resulting from the use of
all current and pending uses of any triazole-derived fungicide. The
risk assessment is a highly conservative, screening-level evaluation in
terms of hazards associated with common metabolites (e.g., use of a
maximum combination of uncertainty factors) and potential dietary and
non-dietary exposures (i.e., high end estimates of both dietary and
non-dietary exposures). In addition, the Agency retained the additional
10X FQPA safety factor for the protection of infants and children. The
assessment includes evaluations of risks for various subgroups,
including those comprised of infants and children. The Agency's
complete risk assessment is found in the propiconazole reregistration
docket at http://www.regulations.gov, Docket Identification (ID) Number
EPA-HQ-OPP-2005-0497.
D. Safety Factor for Infants and Children
1. In general. Section 408(b)(2)(C) of FFDCA provides that EPA
shall apply an additional tenfold (10X) 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 database on toxicity
and exposure unless EPA determines based on reliable data that a
different margin of safety will be safe for infants and children. This
additional margin of safety is commonly referred to as the FQPA Safety
Factor (SF). In applying this provision, EPA either retains the default
value of 10X, or uses a different additional safety factor when
reliable data available to EPA support the choice of a different
factor.
2. Prenatal and postnatal sensitivity. EPA determined that the
available data indicated no increased susceptibility of rats or rabbits
to in utero and/or postnatal exposure to difenoconazole. In the
prenatal developmental toxicity studies in rats and rabbits and the 2-
generation reproduction study in rats, toxicity to the fetuses/
offspring, when observed, occurred at equivalent or higher doses than
in the maternal/parental animals. In the prenatal developmental
toxicity study in rats, maternal toxicity was manifested as decreased
body weight gain and food consumption at the LOAEL of 85 mg/kg/day; the
NOAEL was 16 mg/kg/day. The developmental toxicity was manifested as
alterations in fetal ossifications at 171 mg/kg/day; the developmental
NOAEL was 85 mg/kg/day. In a developmental toxicity study in rabbits,
maternal and developmental toxicity were seen at the same dose level
(75 mg/kg/day). Maternal toxicity in rabbits were manifested as
decreased body weight gain and decreased food consumption, while
developmental toxicity was manifested as decreased fetal weight. In a
2-generation reproduction study in rats, there were decreases in
maternal body weight gain and decreases in body weights of
F1 males at the LOAEL of 12.5 mg/kg/day; the parental
systemic and off spring toxicity NOAEL was 1.25 mg/kg/day.
3. Conclusion. EPA has determined that reliable data show the
safety of infants and children would be adequately protected if the
FQPA SF
[[Page 11348]]
were reduced to 1x. That decision is based on the following findings:
i. The toxicity database is adequate for conducting a FQPA risk
assessment. At this time, an immunotoxicity study is not available.
However, the toxicology database for difenocanazole does not show any
evidence of treatment-related effects on the immune system. The overall
weight of evidence suggests that this chemical does not directly target
the immune system. An immunotoxicity study is now required as a part of
new data requirements in the 40 CFR part 158 for conventional pesticide
registration; however, the Agency does not believe that conducting a
functional immunotoxicity study will result in a lower point of
departure (POD) than that currently in use for overall risk assessment,
and therefore, a database uncertainty factor (UFDB) is not needed to
account for lack of this study.
ii. The acute and subchronic neurotoxicity studies in rats are
available. These data show that difenoconazole exhibits some evidence
of neurotoxicity in the database, but the effects are transient or
occur at doses exceeding the limit dose. EPA concluded that
difenoconazole is not a neurotoxic compound. Based on the toxicity
profile, and lack of neurotoxicity, a developmental neurotoxicity study
in rats is not required nor is an additional database uncertainty
factor needed to account for the lack of this study.
iii. There is no evidence that difenoconazole results in increased
susceptibility of rats or rabbit fetuses to in utero and/or postnatal
exposure in the developmental and reproductive toxicity data.
iv. There are no residual uncertainties identified in the exposure
databases. A conservative dietary food exposure assessment was
conducted. Acute dietary food exposure assessments were performed based
on tolerance-level residues, 100 PCT, and the available empirical or
DEEMTM (ver. 7.81) default processing factors. Chronic
dietary exposure assessments were based on tolerance-level residues for
some commodities, average field trial residues for the majority of
commodities, the available empirical or DEEMTM (ver. 7.81)
default processing factors, and 100 PCT. These are conservative
approaches and are unlikely to understate the residues in food
commodities.
EPA also made conservative (protective) assumptions in the ground
water and surface water modeling used to assess exposure to
difenoconazole in drinking water. Post-application exposure of children
as well as incidental oral exposure of toddlers is not expected. These
assessments will not underestimate the exposure and risks posed by
difenoconazole.
E. Aggregate Risks and Determination of Safety
EPA determines whether acute and chronic dietary pesticide
exposures are safe by comparing aggregate exposure estimates to the
acute PAD (aPAD) and chronic PAD (cPAD). For linear cancer risks, EPA
calculates the lifetime probability of acquiring cancer given the
estimated aggregate exposure. Short-, intermediate-, and chronic-term
risks are evaluated by comparing the estimated aggregate food, water,
and residential exposure to the appropriate PODs to ensure that an
adequate MOE exists. Cancer risk was assessed using the same exposure
estimates as discussed in Unit III.C.1.ii., ``chronic exposure.''
1. Acute risk. Using the exposure assumptions discussed in this
unit for acute exposure, the acute dietary exposure from food and water
to difenoconazole will occupy 16% of the aPAD for children 1 to 2 years
old, the population group receiving the greatest exposure.
2. Chronic risk. Using the exposure assumptions described in this
unit for chronic exposure, EPA has concluded that chronic exposure to
difenoconazole from food and water will utilize 45% of the cPAD for
children 1 to 2 years old, the population group receiving the greatest
exposure. Based on the explanation in Unit III.C.3., regarding
residential use patterns, chronic residential exposure to residues of
difenoconazole is not expected.
3. Short-term risk. Short-term aggregate exposure takes into
account short-term residential exposure plus chronic exposure to food
and water (considered to be a background exposure level).
Difenoconazole is currently registered for ornamentals that could
result in short-term residential exposure, and the Agency has
determined that it is appropriate to aggregate chronic exposure through
food and water with short-term residential exposures to difenoconazole.
Using the exposure assumptions described in this unit for short-
term exposures, EPA has concluded that the combined short-term food,
water, and residential exposures result in aggregate MOEs of 180 or
greater. Because EPA's level of concern for difenoconazole is a MOE of
100 or below, these MOEs resulting from short-termed exposure to
difenoconazole are not of concern.
4. Intermediate-term risk. Intermediate-term aggregate exposure
takes into account intermediate-term residential exposure plus chronic
exposure to food and water (considered to be a background exposure
level).
An intermediate-term adverse effect was identified; however,
difenoconazole is not registered for any use patterns that would result
in intermediate-term residential exposure. Intermediate-term risk is
assessed based on intermediate-term residential exposure plus chronic
dietary exposure. Because there is no intermediate-term residential
exposure and chronic dietary exposure has already been assessed under
the appropriately protective cPAD (which is at least as protective as
the POD used to assess intermediate-term risk), no further assessment
of intermediate-term risk is necessary, and EPA relies on the chronic
dietary risk assessment for evaluating intermediate-term risk for
difenoconazole.
5. Aggregate cancer risk for U.S. population. As discussed in Unit
III.C.1.iii., the chronic dietary risk assessment is protective of any
potential cancer effects.
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, or to infants and children from aggregate
exposure to difenoconazole residues.
IV. Other Considerations
A. Analytical Enforcement Methodology
An adequate tolerance enforcement method, method AG-575B, is
available to enforce the tolerance expression. The method determines
residues of difenoconazole per se in or on crop commodities by gas
chromatography with nitrogen-phosphorus detection (GC/NPD). The
method's limits of quantitation (LOQs) are 0.01-0.05 ppm. A
confirmatory GC method with mass-selective detection (MSD) is also
available for crop commodities. Samples from the submitted crop field
trials were analyzed for residues of difenoconazole using a high
performance liquid chromatography method with tandem mass spectrometry
detection (LC/MS/MS), Syngenta REM 147.08, or a similar method. The
methods are adequate for data collection based on acceptable concurrent
method recoveries. The LOQ was 0.01 ppm for difenoconazole in mango and
wax jambu.
The method may be requested from: Chief, Analytical Chemistry
Branch, Environmental Science Center, 701 Mapes Rd., Ft. Meade, MD
20755-5350; telephone number: (410) 305-2905; e-mail address:
[email protected].
[[Page 11349]]
B. International Residue Limits
In making its tolerance decisions, EPA seeks to harmonize U.S.
tolerances with international standards whenever possible, consistent
with U.S. food safety standards and agricultural practices. EPA
considers the international maximum residue limits (MRLs) established
by the Codex Alimentarius Commission (Codex), as required by FFDCA
section 408(b)(4). The Codex Alimentarius is a joint U.N. Food and
Agriculture Organization/World Health Organization food standards
program, and it is recognized as an international food safety
standards-setting organization in trade agreements to which the United
States is a party. EPA may establish a tolerance that is different from
a Codex MRL; however, FFDCA section 408(b)(4) requires that EPA explain
the reasons for departing from the Codex level.
The Codex has established a MRL for difenoconazole in or on mango
at 0.07 ppm. This MRL is the same as the tolerance established by this
action for difenoconzole in the United States. Canadian and Mexican
MRLs have been established for difenoconazole; however, no MRLs have
been established for mango. No Codex, Canadian, and Mexican MRLs have
been established for residues of difenoconazole in or on wax jambu.
C. Response to Comments
There were no public comments received on the Notice of Filing.
D. Revisions to Petitioned-For Tolerances
EPA has revised the tolerance levels proposed in the notice of
filing for mango from 0.09 ppm to 0.07 ppm. The modification was made
based on the available data supporting the use of difenoconazole on
mango and to achieve harmonization with the established Codex MRL of
0.07 ppm residues in or on mango.
Also, the Agency corrected the commodities named in the notice from
``mango fruit'' to ``mango'' and ``waxapple'' to ``wax jambu'' to
reflect EPA's prescribled terminology for these crops.
V. Conclusion
Therefore, tolerances are established for residues of
difenoconazole, 1-[2-[2-chloro-4-(4-chlorophenoxy)phenyl]-4-methyl-1,3-
dioxolan-2-ylmethyl]-1H-1,2,4-triazole, in or on mango at 0.07 ppm and
wax jambu at 1.5 ppm.
VI. Statutory and Executive Order Reviews
This final rule establishes tolerances under section 408(d) of
FFDCA 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 final rule has been
exempted from review under Executive Order 12866, this final rule is
not subject to Executive Order 13211, entitled Actions Concerning
Regulations That Significantly Affect Energy Supply, Distribution, or
Use (66 FR 28355, May 22, 2001) or Executive Order 13045, entitled
Protection of Children from Environmental Health Risks and Safety Risks
(62 FR 19885, April 23, 1997). 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., 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).
Since tolerances and exemptions that are established on the basis
of a petition under section 408(d) of FFDCA, 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.
This final rule directly regulates growers, food processors, food
handlers, and food retailers, not States or Tribes, nor does this
action alter the relationships or distribution of power and
responsibilities established by Congress in the preemption provisions
of section 408(n)(4) of FFDCA. As such, the Agency has determined that
this action will not have a substantial direct effect on States or
Tribal governments, on the relationship between the national government
and the States or Tribal governments, or on the distribution of power
and responsibilities among the various levels of government or between
the Federal Government and Indian Tribes. Thus, the Agency has
determined that Executive Order 13132, entitled Federalism (64 FR
43255, August 10, 1999) and Executive Order 13175, entitled
Consultation and Coordination with Indian Tribal Governments (65 FR
67249, November 9, 2000) do not apply to this final rule. In addition,
this final rule does not impose any enforceable duty or contain any
unfunded mandate as described under Title II of the Unfunded Mandates
Reform Act of 1995 (UMRA) (Pub. L. 104-4).
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).
VII. Congressional Review Act
The Congressional Review Act, 5 U.S.C. 801 et seq., generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report 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: February 18, 2011.
Daniel J. Rosenblatt,
Acting Director, Registration Division, Office of Pesticide Programs.
Therefore, 40 CFR chapter I is amended as follows:
PART 180--[AMENDED]
0
1. The authority citation for part 180 continues to read as follows:
Authority: 21 U.S.C. 321(q), 346a and 371.
0
2. Section 180.475 is amended by alphabetically adding the following
commodities to the table in paragraph (a)(1) to read as follows:
Sec. 180.475 Difenoconazole; tolerance for residues.
(a) * * *
(1) * * *
------------------------------------------------------------------------
Parts per
Commodity million
------------------------------------------------------------------------
* * * * *
Mango \1\................................................. 0.07
* * * * *
Wax jambu \1\............................................. 1.5
------------------------------------------------------------------------
[[Page 11350]]
* * * * *
[FR Doc. 2011-4370 Filed 3-1-11; 8:45 am]
BILLING CODE 6560-50-P