Tebuconazole; Pesticide Tolerances, 54127-54133 [2011-22138]
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Federal Register / Vol. 76, No. 169 / Wednesday, August 31, 2011 / Rules and Regulations
ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Part 180
[ EPA–HQ–OPP–2011–0120; FRL–8885–4]
Tebuconazole; Pesticide Tolerances
Environmental Protection
Agency (EPA).
ACTION: Final rule.
AGENCY:
This regulation establishes
tolerances for residues of tebuconazole
in or on wheat, grain; oats, grain; wheat,
shorts; and wheat, germ. Bayer
CropScience requested these tolerances
under the Federal Food, Drug, and
Cosmetic Act (FFDCA).
DATES: This regulation is effective
August 31, 2011. Objections and
requests for hearings must be received
on or before October 31, 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–2011–0120. All documents in the
docket are listed in the docket index
available at https://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
https://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:
Tracy Keigwin, Registration Division
(7505P), Office of Pesticide Programs,
Environmental Protection Agency, 1200
Pennsylvania Ave., NW., Washington,
DC 20460–0001; telephone number:
(703) 305–6605; e-mail address:
keigwin.tracy@epa.gov.
SUPPLEMENTARY INFORMATION:
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SUMMARY:
I. General Information
A. Does this action apply to me?
You may be potentially affected by
this action if you are an agricultural
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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 https://ecfr.gpoaccess.gov/cgi/t/
text/text-idx?&c=ecfr&tpl=/ecfrbrowse/
Title40/40tab_02.tpl.
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–2011–0120 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 October 31, 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
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54127
request, identified by docket ID number
EPA–HQ–OPP–2011–0120, by one of
the following methods:
• Federal eRulemaking Portal: https://
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
Tolerance
In the Federal Register of March 29,
2011 (76 FR 17374) (FRL–8867–4), 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 0F7792 by Bayer
CropScience, 2 T.W. Alexander Drive,
P.O. Box 12014, Research Triangle Park,
NC 27709. The petition requested that
40 CFR 180.474 be amended by revising
tolerances for residues of the fungicide
tebuconazole in or on wheat, grain; and
oats, grain to 0.15 ppm in order to
harmonize with MRLs established in
Canada by PMRA. That notice
referenced a summary of the petition
prepared by Bayer CropScience, the
registrant, which is available in the
docket, https://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
determined that tolerances on the
following processed forms of wheat and
oats are needed also: Wheat, shorts and
wheat, germ, each at 0.20 ppm.
Additionally, the Agency is establishing
tolerances for tebuconazole of 0.20 ppm
in shorts and germ of wheat. The
reasons these additional tolerances are
needed is explained in Unit IV.C.
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
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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 tebuconazole
including exposure resulting from the
tolerances established by this action.
EPA’s assessment of exposures and risks
associated with tebuconazole 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.
Tebuconazole has low acute toxicity
by the oral or dermal route of exposure,
and moderate toxicity by the inhalation
route. It is not a dermal sensitizer or a
dermal irritant; however, it is slightly to
mildly irritating to the eye. With
repeated dosing, the primary target
organs of tebuconazole toxicity are the
liver, the adrenals, the hematopoetic
system and the nervous system. Effects
on these target organs were seen in both
rodent and non-rodent species. In
addition, ocular lesions were seen in
dogs (including lenticular degeneration
and increased cataract formation)
following subchronic or chronic
exposure. Oral administration of
tebuconazole caused developmental
toxicity in all species evaluated (rat,
rabbit and mouse), with the most
prominent effects in the nervous system.
The developmental toxicity studies,
including the developmental
neurotoxicity study, demonstrated an
increase in susceptibility in developing
fetuses both quantitatively and
qualitatively.
Tebuconazole was classified as a
Group C possible human carcinogen
based on an increase in the incidence of
hepatocellular adenomas, carcinomas,
and combined adenomas/carcinomas in
male and female mice. Mutagenicity
data did not demonstrate any evidence
of mutagenic potential for tebuconazole.
Specific information on the studies
received and the nature of the adverse
effects caused by tebuconazole as well
as the no-observed-adverse-effect-level
(NOAEL) and the lowest-observedadverse-effect-level (LOAEL) from the
toxicity studies can be found at https://
www.regulations.gov in document
entitled ‘‘Tebuconazole: Human Health
Risk Assessment to harmonize
Tolerances of Tebuconazole in/on Oats
and Wheat with Canada,’’ pp. 32–37 in
docket ID number EPA–HQ–OPP–2011–
0120.
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 https://
www.epa.gov/pesticides/factsheets/
riskassess.htm.
A summary of the toxicological
endpoints for tebuconazole used for
human risk assessment is shown in the
Table of this unit.
TABLE—SUMMARY OF TOXICOLOGICAL DOSES AND ENDPOINTS FOR TEBUCONAZOLE FOR USE IN HUMAN HEALTH RISK
ASSESSMENT
Exposure/scenario
Point of departure and
uncertainty/safety factors
RfD, PAD, LOC for risk
assessment
Study and toxicological effects
Acute dietary (General population including infants
and children) (Females
13–50 years of age).
LOAEL = 8.8 mg/kg/day ....
UF = 300
UFA = 10x
UFH = 10x
FQPA (UFL) = 3x
LOAEL = 8.8 mg/kg/day ....
UF = 300
UFA = 10x
UFH = 10x
FQPA (UFL) = 3x
LOAEL = 8.8 mg/kg/day ....
UF = 300
UFA = 10x
UFH = 10x
FQPA (UFL) = 3x
Acute RfD = 0.029 mg/kg/
day.
aPAD = 0.029 mg/kg/day
Developmental Neurotoxicity Study—Rat. LOAEL =
8.8 mg/kg/day based on decreases in body weights,
absolute brain weights, brain measurements and
motor activity in offspring.
Chronic RfD = 0.029 mg/
kg/day.
cPAD = 0.029 mg/kg/day
Developmental Neurotoxicity Study—Rat.
LOAEL = 8.8 mg/kg/day based on decreases in body
weights, absolute brain weights, brain measurements and motor activity in offspring.
Residential LOC for MOE
= 300.
Developmental Neurotoxicity Study—Rat. LOAEL =
8.8 mg/kg/day based on decreases in body weights,
absolute brain weights, brain measurements and
motor activity in offspring.
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Chronic dietary (All populations).
Incidental oral short-term/Intermediate term (1 to 30
days/1 to 6 months).
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TABLE—SUMMARY OF TOXICOLOGICAL DOSES AND ENDPOINTS FOR TEBUCONAZOLE FOR USE IN HUMAN HEALTH RISK
ASSESSMENT—Continued
Exposure/scenario
Dermal short-term/Intermediate term (1 to 30
days/1 to 6 months).
Inhalation short-term/Intermediate term (1 to 30
days/1 to 6 months).
Cancer (Oral, dermal, inhalation).
Point of departure and
uncertainty/safety factors
LOAEL = 8.8 mg/kg/day ....
UF = 300
UFA = 10x
UFH = 10x
UFL = 3x
DAF = 23.1%
LOAEL = 8.8 mg/kg/day ....
UF = 300
UFA = 10x
UFH = 10x
UFL = 3x
Inhalation and oral absorption are assumed to be
equivalent.
RfD, PAD, LOC for risk
assessment
Study and toxicological effects
Residential LOC for MOE
= 300.
Developmental Neurotoxicity Study—Rat.
LOAEL = 8.8 mg/kg/day based on decreases in body
weights, absolute brain weights, brain measurements and motor activity in offspring.
Residential LOC for MOE
= 300.
Developmental Neurotoxicity Study—Rat.
LOAEL = 8.8 mg/kg/day based on decreases in body
weights, absolute brain weights, brain measurements and motor activity in offspring.
Classification: Group C—possible human carcinogen based on statistically significant increase in the incidence of
hepatocellular adenoma, carcinoma, and combined adenoma/carcinomas in both sexes of NMRI mice. Considering that there was no evidence of carcinogenicity in rats, there was no evidence of genotoxicity for
tebuconazole, and tumors were only seen at a high and excessively toxic dose in mice, EPA concluded that the
chronic RfD would be protective of any potential carcinogenic effect. The chronic RfD value is 0.029 mg/kg/day
which is approximately 9,600 fold lower than the dose that would induce liver tumors (279 mg/kg/day).
UFA = extrapolation from animal to human (interspecies). UFH = potential variation in sensitivity among members of the human population
(intraspecies). UFL = use of a LOAEL to extrapolate a NOAEL. UFS = use of a short-term study for long-term risk assessment. UFDB = to account
for the absence of data or other data deficiency. 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. DAF = dermal absorption factor.
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C. Exposure Assessment
1. Dietary exposure from food and
feed uses. In evaluating dietary
exposure to tebuconazole, EPA
considered exposure under the
petitioned-for tolerances as well as all
existing tebuconazole tolerances in 40
CFR 180.474. EPA assessed dietary
exposures from tebuconazole 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.
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, anticipated residues for
bananas, grapes, raisins, nectarines,
peaches, and peanut butter were derived
using the 2002–2006 USDA Pesticide
Data Program (PDP) monitoring data.
Anticipated residues for all other
registered food commodities were based
on field trial data. For uses associated
with PP 0F7792, 100 percent crop
treated (PCT) was assumed. DEEM (ver.
7.81) default processing factors were
assumed for processed commodities
associated with petition 0F7792. For
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several other uses EPA used PCT data as
specified in Unit III.C.1.iv.
ii. Chronic exposure. In conducting
the chronic dietary exposure
assessment, EPA used the same data
sources as stated in Unit III. C. 1. i. for
acute exposure.
iii. Cancer. As explained in Unit
III.B., the chronic risk assessment is
considered to be protective of any
cancer effects; therefore, a separate
quantitative cancer dietary risk
assessment was not conducted.
iv. Anticipated residue and PCT
information. 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.
Section 408(b)(2)(F) of FFDCA states
that the Agency may use data on the
actual percent of food treated for
assessing chronic dietary risk only if:
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• Condition a: 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 the pesticide residue.
• Condition b: The exposure estimate
does not underestimate exposure for any
significant subpopulation group.
• Condition c: 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 FFDCA section 408(b)(2)(F),
EPA may require registrants to submit
data on PCT.
The Agency estimated the PCT for
existing uses as follows:
Grapes: 25% acute assessment, 15%
chronic assessment; grape, raisin: 25%
acute assessment, 15% chronic
assessment; nectarine: 25% acute
assessment, 20% chronic assessment;
peach: 20% acute assessment, 15%
chronic assessment; and peanuts: 45%
acute assessment, 15% chronic
assessment.
In most cases, EPA uses available data
from United States Department of
Agriculture/National Agricultural
Statistics Service (USDA/NASS),
proprietary market surveys, and the
National Pesticide Use Database for the
chemical/crop combination for the most
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recent 6–7 years. EPA uses an average
PCT for chronic dietary risk analysis.
The average PCT figure for each existing
use is derived by combining available
public and private market survey data
for that use, averaging across all
observations, and rounding to the
nearest 5%, except for those situations
in which the average PCT is less than
one. In those cases, 1% is used as the
average PCT and 2.5% is used as the
maximum PCT. EPA uses a maximum
PCT for acute dietary risk analysis. The
maximum PCT figure is the highest
observed maximum value reported
within the recent 6 years of available
public and private market survey data
for the existing use and rounded up to
the nearest multiple of 5%.
The Agency also used PCT
information for tebuconazole on the
following recently approved uses:
Apples, apricots, cherries (preharvest),
sweetcorn, hops, plums, and turnips.
The PCT for each crop is as follows:
Apples, acute assessment 44%, chronic
assessment 41%; Apricots, acute
assessment 56%, chronic assessment
43%; Cherries, preharvest, acute
assessment 42%, chronic assessment
37%; Corn, sweet, acute assessment
22%, chronic assessment 14%; Hops,
acute assessment 64%, chronic
assessment 64%; Plum, acute
assessment 26%, chronic assessment
24%; Turnip, acute assessment 68%,
chronic assessment 44%. EPA estimates
PCT for a new pesticide use by
assuming that its actual PCT during the
initial five years of use on a specific use
site will not exceed the recent PCT of
the market leader (i.e. ,the one with the
greatest PCT) on that site. An average
market leader PCT, based on three
recent surveys of pesticide usage, if
available, is used for chronic risk
assessment, while the maximum PCT
from the same three recent surveys, if
available, is used for acute risk
assessment. The average and maximum
market leader PCTs may each be based
on one or two surveys if three are not
available. Comparisons are only made
among pesticides of the same pesticide
type (i.e., the leading fungicide on the
use site is selected for comparison with
the new fungicide). The market leader
PCTs used to determine the average and
the maximum may be each for the same
pesticide or for different pesticides
since the same or different pesticides
may dominate for each year. Typically,
EPA uses USDA/NASS as the source for
raw PCT data because it is publicly
available. When a specific use site is not
surveyed by USDA/NASS, EPA uses
other sources including proprietary
data.
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An estimated PCT, based on the
average PCT of the market leaders, is
appropriate for use in chronic dietary
risk assessment, and an estimated
projected percent crop treated (PPCT),
based on the maximum PCT of the
market leaders, is appropriate for use in
acute dietary risk assessment. This
method of estimating PCTs for a new
use of a registered pesticide or a new
pesticide produces high-end estimates
that are unlikely, in most cases, to be
exceeded during the initial five years of
actual use. Predominant factors that
bear on whether the PCTs could be
exceeded may include PCTs of similar
chemistries, pests controlled by
alternatives, pest prevalence in the
market and other factors. Based on these
factors, EPA has adjusted upward the
estimates for three crops: Cherries postharvest, hops and turnip greens.
The Agency believes that the three
conditions discussed in Unit III.C.1.iv.
have been met. With respect to
Condition a, PCT estimates are derived
from Federal and private market survey
data, which are reliable and have a valid
basis. The Agency is reasonably certain
that the percentage of the food treated
is not likely to be an underestimation.
As to Conditions b and c, 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 reliable information on
the regional consumption of food to
which tebuconazole may be applied in
a particular area.
2. Dietary exposure from drinking
water. The Agency used screening level
water exposure models in the dietary
exposure analysis and risk assessment
for tebuconazole in drinking water.
These simulation models take into
account data on the physical, chemical,
and fate/transport characteristics of
tebuconazole. Further information
regarding EPA drinking water models
used in pesticide exposure assessment
can be found at https://www.epa.gov/
oppefed1/models/water/index.htm.
Surface water estimated drinking
water concentrations (EDWCs) resulting
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from the Pesticide Root Zone Model/
Exposure Analysis Modeling System
(PRZM/EXAMS) were used in the
dietary assessment, since they were
higher than the EDWCs resulting from
the Screening Concentration in Ground
Water (SCI GROW). A distribution of 30year daily surface water concentrations
was estimated for the EDWCs of
tebuconazole for acute exposures. The
EDWC for chronic, noncancer exposure
is estimated to be 59.0 μg/L for surface
water.
3. From non-dietary exposure. The
term ‘‘residential exposure’’ is used in
this document to refer to nonoccupational, non-dietary exposure
(e.g., for lawn and garden pest control,
indoor pest control, termiticides, and
flea and tick control on pets).
Tebuconazole has currently registered
uses that could result in residential
exposures. Short-term dermal and
inhalation exposures are possible for
residential adult handlers mixing,
loading, and applying tebuconazole
products outdoors to ornamental plants.
Short- and intermediate-term dermal
postapplication exposures are also
possible to golfers from treated golf turf
and to adults and children from contact
to treated wood structures. Children
may also be exposed via the incidental
oral route when playing on treated
wood structures. Long-term exposure is
not expected. As a result, risk
assessments have been completed for
residential handler scenarios as well as
residential post-application scenarios.
Further information regarding EPA
standard assumptions and generic
inputs for residential exposures may be
found at https://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.’’
Tebuconazole is a member of the
triazoles (and more specifically,
triazole-derivative fungicides). Although
triazoles 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 triazole-
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derivative fungicides, however, a
variable pattern of toxicological
responses is found: Some are
hepatotoxic and hepatocarcinogenic in
mice; some induce thyroid tumors in
rats; and some induce developmental,
reproductive, and neurological effects in
rodents. Furthermore, the triazoles
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
triazole-derivative fungicides share
common mechanisms of toxicity and
EPA is not following a cumulative risk
approach based on a common
mechanism of toxicity for the triazolederivative fungicides. 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 https://
www.epa.gov/pesticides/cumulative.
However, the triazole-derivative
fungicides can form the common
metabolites 1,2,4-triazole and
conjugated triazole metabolites. To
support existing tolerances and to
establish new tolerances for triazolederivative fungicides, including
tebuconazole, 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-derivative 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 at https://www.regulations.gov,
docket ID number EPA–HQ–OPP–2011–
0120 in the document entitled
‘‘Common Triazole Metabolites:
Updated Dietary (Food + Water)
Exposure and Risk Assessment to
Address the Amended Metconazole
Section 3 Registration to Add Uses on
Tuberous and Corm Vegetables (Group
1C) and Bushberry Subgroup 13–07B’’.
This document updates another EPA
risk assessment on triazole-derived
pesticides which can be found in the
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reregistration docket for propiconazole
at https://www.regulations.gov, docket 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.
The toxicity database for tebuconazole
includes prenatal developmental
toxicity studies in three species (mouse,
rat, and rabbit), a reproductive toxicity
study in rats, acute and subchronic
neurotoxicity studies in rats, and a
developmental neurotoxicity study in
rats. The data from prenatal
developmental toxicity studies in mice
and a developmental neurotoxicity
study in rats indicated an increased
quantitative and qualitative
susceptibility following in utero
exposure to tebuconazole. The NOAELs/
LOAELs for developmental toxicity in
these studies were found at dose levels
less than those that induce maternal
toxicity or in the presence of slight
maternal toxicity. There was no
indication of increased quantitative
susceptibility in the rat and rabbit
developmental toxicity studies, the
NOAELs for developmental toxicity
were comparable to or higher than the
NOAELs for maternal toxicity. In all
three species, however, there was
indication of increased qualitative
susceptibility. For most studies,
minimal maternal toxicity was seen at
the LOAEL (consisting of increases in
hematological findings in mice,
increased liver weights in rabbits and
rats, and decreased body weight gain/
food consumption in rats) and did not
increase substantially in severity at
higher doses; however, there was more
concern for the developmental effects at
each LOAEL which included increases
in runts, increased fetal loss, and
malformations in mice, increased
skeletal variations in rats, and increased
fetal loss and frank malformations in
rabbits. Additionally, more severe
developmental effects (including frank
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54131
malformations) were seen at higher
doses in mice, rats and rabbits. In the
developmental neurotoxicity study,
maternal toxicity was seen only at the
high dose (decreased body weights,
body weight gains, and food
consumption, prolonged gestation with
mortality, and increased number of dead
fetuses), while offspring toxicity
(including decreases in body weight,
brain weight, brain measurements and
functional activities) was seen at all
doses.
Available data indicated greater
sensitivity of the developing organism
to exposure to tebuconazole, as
demonstrated by increases in qualitative
sensitivity in prenatal developmental
toxicity studies in rats, mice, and
rabbits, and by increases in both
qualitative and quantitative sensitivity
in the developmental neurotoxicity
study in rats with tebuconazole.
However, the degree of concern is low
because the toxic endpoints in the
prenatal developmental toxicity studies
were well characterized with clear
NOAELs established and the most
sensitive endpoint, which is found in
the developmental neurotoxicity study,
has been used for overall risk
assessments. Therefore, there are no
residual uncertainties for pre- and/or
postnatal susceptibility.
3. Conclusion. The Agency has
determined that reliable data show the
safety of infants and children would be
adequately protected if the FQPA SF
were reduced to 3x for all potential
exposure scenarios. The decision is
based on the following findings:
i. The toxicity database for
tebuconazole is complete with the
exception of an immunotoxicity study
requirement under the new 40 CFR part
158 guidelines for toxicity data. The
available guideline studies do not
suggest that tebuconazole directly
targets the immune system. A peerreviewed developmental neurotoxicity/
immunotoxicity literature study found
in high dose groups (60 mg/kg/day)
increased spleen weights and alterations
in splenic lymphocyte subpopulations.
At the same dose there were no effects
seen in the T-cell dependent antibody
response to sheep red blood cells
(SRBC) and natural killer (NK) cell
activity indicating that tebuconazole did
not alter the functional immune
response in rats. Based on guideline and
open literature, the overall weight of
evidence suggests that tebuconazole
does not directly target the immune
system. The Agency does not believe
that conducting a functional
immunotoxicity study will result in a
lower POD than currently used for
overall risk assessment; therefore, a
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database uncertainty factor (UFDB) is
not needed to account for the lack of the
study.
ii. Although there is qualitative
evidence of increased susceptibility in
the prenatal developmental studies in
rats, the Agency did not identify any
residual uncertainties after establishing
toxicity endpoints and traditional UFs
to be used in the risk assessment of
tebuconazole. The degree of concern for
residual uncertainties for prenatal and/
or postnatal toxicity is low.
iii. A 3x FQPA safety factor is needed
to address the failure to achieve a
NOAEL in the developmental
neurotoxicity (DNT) study. Reduction of
the FQPA safety factor from 10x to 3x
is based on a Benchmark Dose (BMD)
analysis of the datasets relevant to the
adverse offspring effects (decreased
body weight, decreases in absolute brain
weights, changes in brain morphometric
parameters, and decreases in motor
activity) seen at the LOAEL in the DNT
study. The BMD analysis models or
estimates the dose (BMD) associated
with a specified measure or change (e.g.
a dose representing a 10% change) of a
biological effect over the control. All of
the BMDLs (the lower limit of a onesided 95% confidence interval on the
BMD) modeled successfully on
statistically significant effects are 1–2x
lower than the LOAEL. The results
indicate that the use of the FQPA safety
factor of 3x would not underestimate
risk. Using a 3x FQPA safety factor in
the risk assessment (8.8 mg/kg/day ÷ 3x
= 2.9 mg/kg/day) is further supported by
the NOAELs established in other studies
in the tebuconazole toxicity database
[i.e., 3 and 2.9 mg/kg/day, from a DNT
study in mice and a chronic toxicity
study in dogs, respectively (respective
LOAELs 10 and 4.5 mg/kg/day)].
iv. There are no residual uncertainties
identified in the exposure databases.
Although the acute and chronic food
exposure assessments are refined, EPA
believes that the assessments are based
on reliable data and will not
underestimate exposure/risk. The
drinking water estimates were derived
from conservative screening models.
The residential exposure assessment
utilizes reasonable high-end variables
set out in EPA’s Occupational/
Residential Exposure SOPs (Standard
Operating Procedures). The aggregate
assessment is based upon reasonable
worst-case residential assumptions, and
is also not likely to underestimate
exposure/risk to any subpopulation,
including those comprised of infants
and children.
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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.
1. Acute risk. Using the exposure
assumptions discussed in this unit for
acute exposure, the acute dietary
exposure from food and water to
tebuconazole will occupy 33% of the
aPAD for the U.S. population and 62%
of the aPAD for the population group
(children 3–5 years old) 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 tebuconazole
from food and water will utilize 8.8% of
the cPAD for the U.S. population and
16% of the cPAD for the most highly
exposed population group (all infants (<
1 year old).
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). Tebuconazole is
currently registered for uses 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 tebuconazole.
Using the exposure assumptions
described in this unit for short term
exposures, EPA has concluded that the
short-term aggregate MOE from dietary
exposure (food + drinking water) and
non-occupational/residential handler
exposure for adults using a hose-end
sprayer on ornamentals is 370. The
short-term aggregate MOE from dietary
exposure and exposure from golfing is
1,900. The likelihood of a residential
handler treating ornamentals with
tebuconazole and then playing golf on a
tebuconazole-treated course is
considered low; therefore, each scenario
is considered separately with
background dietary exposure. The shortterm aggregate MOE to children from
dietary exposure and exposure from
wood surfaces treated at the above
ground use rate is 470. The short-term
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aggregate MOE to children from dietary
exposure and exposure to wood surfaces
treated at the below ground use rate is
220. The combined and aggregate MOEs
for wood treated for below ground uses
are lower than the target MOE (300) and
thus indicate a potential risk of concern.
However, the combined MOE for wood
treated for above-ground uses is not
lower than the target MOE, and
therefore is not of concern. Exposure to
above-ground wood is expected to more
closely represent actual exposures to
children. Frequency of exposures to
above-ground wood should greatly
exceed any exposures to below-ground
wood, and exposures to below ground
wood would be minimal, or negligible.
It is unrealistic to expect a full duration
of exposure to below ground wood.
Therefore, EPA concludes that there is
not a concern for short-term aggregate
risk.
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).
Tebuconazole is currently registered for
uses that could result in intermediateterm residential exposure, and the
Agency has determined that it is
appropriate to aggregate chronic
exposure through food and water with
intermediate-term residential exposures
to tebuconazole. Since the POD,
relevant exposure scenarios and
exposure assumptions used for
intermediate-term aggregate risk
assessments are the same as those used
for short-term aggregate risk
assessments, the short-term aggregate
risk assessments represent and are
protective of both short and
intermediate-term exposure durations.
5. Aggregate cancer risk for U.S.
population. As discussed in this unit,
the chronic risk assessment is
considered to be protective of any
cancer effects; therefore, because the
chronic risk assessment indicates
exposure is lower than the cPAD,
tebuconazole does not pose a cancer risk
of concern.
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 tebuconazole
residues.
IV. Other Considerations
A. Analytical Enforcement Methodology
Adequate gas chromatography/
nitrogen phosphorous detector (GC/
NPD) and liquid chromatography/mass
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spectrometry/mass spectrometry (LC/
MS/MS) methods are available for both
collecting and enforcing tolerances for
tebuconazole and its metabolites in
plant commodities, livestock matrices
and processing studies. The methods
have been adequately validated by an
independent laboratory in conjunction
with a previous petition. 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; email address: residuemethods@epa.gov.
B. International Residue Limits
Codex and Canada have established
maximum residue limits (MRLs) for
tebuconazole in/on a variety of plant
and livestock commodities. The
tolerance expression for tebuconazole is
harmonized between U.S., Codex, and
Canada. The proposed tolerances will
harmonize established U.S. tolerances
on oat and wheat with current Canadian
MRLs.
There are currently no Codex MRLs
for wheat and oats.
C. Revisions to Petitioned-For
Tolerances
The Agency concluded that residues
of tebuconazole do not concentrate in
wheat bran, flour or middlings, but do
concentrate in shorts and germ (2.5X).
As a result, a tolerance in/on wheat,
shorts and wheat, germ, each at 0.20
ppm (highest average field trial (HAFT)
value = 0.08 ppm), is required.
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V. Conclusion
Therefore, tolerances are established
for residues of tebuconazole, in or on
wheat, grain, and oat, grain at 0.15 ppm
and wheat, shorts, and wheat, germ at
0.20 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).
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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
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Representatives, and the Comptroller
General of the United States prior to
publication of this final rule in the
Federal Register. This final rule is not
a ‘‘major rule’’ as defined by 5 U.S.C.
804(2).
List of Subjects in 40 CFR Part 180
Environmental protection,
Administrative practice and procedure,
Agricultural commodities, Pesticides
and pests, Reporting and recordkeeping
requirements.
Dated: August 17, 2011.
Lois Rossi,
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), 346a and 371.
2. Section 180.474, paragraph (a)(1) is
amended by:
■ i. Revising the introductory text;
■ ii. Revising the entries for ‘‘oat, grain’’
and ‘‘wheat, grain’’ in the table; and
■ iii. Alphabetically adding entries for
‘‘wheat, shorts’’ and ‘‘wheat, germ’’ to
the table.
The amendments read as follows:
■
§ 180.474 Tebuconazole; tolerances for
residues.
(a) * * *
(1) Tolerances are established for
residues of tebuconazole, alpha-[2-(4chlorophenyl)ethyl]-alpha-(1,1dimethylethyl)-1H-1,2,4-triazole-1ethanol, including its metabolites and
degradates, in or on the commodities in
the table below. Compliance with the
tolerance levels specified below is to be
determined by measuring only
tebuconazole [a-[2-(4-chlorophenyl)
ethyl]-a-(1,1-dimethylethyl)-1H-1,2,4triazole-1-ethanol], in or on the
commodity.
Parts
per
million
Commodity
*
*
*
*
Oat, grain ......................................
Wheat, grain .................................
Wheat, shorts ...............................
Wheat, germ .................................
*
*
*
*
*
*
*
*
*
[FR Doc. 2011–22138 Filed 8–30–11; 8:45 am]
BILLING CODE 6560–50–P
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0.15
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0.20
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Agencies
[Federal Register Volume 76, Number 169 (Wednesday, August 31, 2011)]
[Rules and Regulations]
[Pages 54127-54133]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-22138]
[[Page 54127]]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[ EPA-HQ-OPP-2011-0120; FRL-8885-4]
Tebuconazole; Pesticide Tolerances
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: This regulation establishes tolerances for residues of
tebuconazole in or on wheat, grain; oats, grain; wheat, shorts; and
wheat, germ. Bayer CropScience requested these tolerances under the
Federal Food, Drug, and Cosmetic Act (FFDCA).
DATES: This regulation is effective August 31, 2011. Objections and
requests for hearings must be received on or before October 31, 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-2011-0120. All documents in the
docket are listed in the docket index available at https://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 https://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: Tracy Keigwin, Registration Division
(7505P), Office of Pesticide Programs, Environmental Protection Agency,
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone
number: (703) 305-6605; e-mail address: keigwin.tracy@epa.gov.
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 https://ecfr.gpoaccess.gov/cgi/t/text/text-idx?&c=ecfr&tpl=/ecfrbrowse/Title40/40tab_02.tpl.
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-2011-0120 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
October 31, 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-2011-0120, by one of the following methods:
Federal eRulemaking Portal: https://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 Tolerance
In the Federal Register of March 29, 2011 (76 FR 17374) (FRL-8867-
4), 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 0F7792
by Bayer CropScience, 2 T.W. Alexander Drive, P.O. Box 12014, Research
Triangle Park, NC 27709. The petition requested that 40 CFR 180.474 be
amended by revising tolerances for residues of the fungicide
tebuconazole in or on wheat, grain; and oats, grain to 0.15 ppm in
order to harmonize with MRLs established in Canada by PMRA. That notice
referenced a summary of the petition prepared by Bayer CropScience, the
registrant, which is available in the docket, https://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
determined that tolerances on the following processed forms of wheat
and oats are needed also: Wheat, shorts and wheat, germ, each at 0.20
ppm. Additionally, the Agency is establishing tolerances for
tebuconazole of 0.20 ppm in shorts and germ of wheat. The reasons these
additional tolerances are needed is explained in Unit IV.C.
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
[[Page 54128]]
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 tebuconazole including
exposure resulting from the tolerances established by this action.
EPA's assessment of exposures and risks associated with tebuconazole
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.
Tebuconazole has low acute toxicity by the oral or dermal route of
exposure, and moderate toxicity by the inhalation route. It is not a
dermal sensitizer or a dermal irritant; however, it is slightly to
mildly irritating to the eye. With repeated dosing, the primary target
organs of tebuconazole toxicity are the liver, the adrenals, the
hematopoetic system and the nervous system. Effects on these target
organs were seen in both rodent and non-rodent species. In addition,
ocular lesions were seen in dogs (including lenticular degeneration and
increased cataract formation) following subchronic or chronic exposure.
Oral administration of tebuconazole caused developmental toxicity in
all species evaluated (rat, rabbit and mouse), with the most prominent
effects in the nervous system. The developmental toxicity studies,
including the developmental neurotoxicity study, demonstrated an
increase in susceptibility in developing fetuses both quantitatively
and qualitatively.
Tebuconazole was classified as a Group C possible human carcinogen
based on an increase in the incidence of hepatocellular adenomas,
carcinomas, and combined adenomas/carcinomas in male and female mice.
Mutagenicity data did not demonstrate any evidence of mutagenic
potential for tebuconazole.
Specific information on the studies received and the nature of the
adverse effects caused by tebuconazole as well as the no-observed-
adverse-effect-level (NOAEL) and the lowest-observed-adverse-effect-
level (LOAEL) from the toxicity studies can be found at https://www.regulations.gov in document entitled ``Tebuconazole: Human Health
Risk Assessment to harmonize Tolerances of Tebuconazole in/on Oats and
Wheat with Canada,'' pp. 32-37 in docket ID number EPA-HQ-OPP-2011-
0120.
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 https://www.epa.gov/pesticides/factsheets/riskassess.htm.
A summary of the toxicological endpoints for tebuconazole used for
human risk assessment is shown in the Table of this unit.
Table--Summary of Toxicological Doses and Endpoints for Tebuconazole for Use in Human Health Risk Assessment
----------------------------------------------------------------------------------------------------------------
Point of departure and
Exposure/scenario uncertainty/safety RfD, PAD, LOC for risk Study and toxicological
factors assessment effects
----------------------------------------------------------------------------------------------------------------
Acute dietary (General population LOAEL = 8.8 mg/kg/day. Acute RfD = 0.029 mg/ Developmental Neurotoxicity
including infants and children) UF = 300.............. kg/day. Study--Rat. LOAEL = 8.8 mg/
(Females 13-50 years of age). UFA = 10x............. aPAD = 0.029 mg/kg/day kg/day based on decreases
UFH = 10x............. in body weights, absolute
FQPA (UFL) = 3x....... brain weights, brain
measurements and motor
activity in offspring.
Chronic dietary (All populations).. LOAEL = 8.8 mg/kg/day. Chronic RfD = 0.029 mg/ Developmental Neurotoxicity
UF = 300.............. kg/day. Study--Rat.
UFA = 10x............. cPAD = 0.029 mg/kg/day LOAEL = 8.8 mg/kg/day based
UFH = 10x............. on decreases in body
FQPA (UFL) = 3x....... weights, absolute brain
weights, brain
measurements and motor
activity in offspring.
Incidental oral short-term/ LOAEL = 8.8 mg/kg/day. Residential LOC for Developmental Neurotoxicity
Intermediate term (1 to 30 days/1 UF = 300.............. MOE = 300. Study--Rat. LOAEL = 8.8 mg/
to 6 months). UFA = 10x............. kg/day based on decreases
UFH = 10x............. in body weights, absolute
FQPA (UFL) = 3x....... brain weights, brain
measurements and motor
activity in offspring.
[[Page 54129]]
Dermal short-term/Intermediate term LOAEL = 8.8 mg/kg/day. Residential LOC for Developmental Neurotoxicity
(1 to 30 days/1 to 6 months). UF = 300.............. MOE = 300. Study--Rat.
UFA = 10x............. LOAEL = 8.8 mg/kg/day based
UFH = 10x............. on decreases in body
UFL = 3x.............. weights, absolute brain
DAF = 23.1%........... weights, brain
measurements and motor
activity in offspring.
Inhalation short-term/Intermediate LOAEL = 8.8 mg/kg/day. Residential LOC for Developmental Neurotoxicity
term (1 to 30 days/1 to 6 months). UF = 300.............. MOE = 300. Study--Rat.
UFA = 10x............. LOAEL = 8.8 mg/kg/day based
UFH = 10x............. on decreases in body
UFL = 3x.............. weights, absolute brain
Inhalation and oral weights, brain
absorption are measurements and motor
assumed to be activity in offspring.
equivalent..
----------------------------------------------------------------------------
Cancer (Oral, dermal, inhalation).. Classification: Group C--possible human carcinogen based on statistically
significant increase in the incidence of hepatocellular adenoma,
carcinoma, and combined adenoma/carcinomas in both sexes of NMRI mice.
Considering that there was no evidence of carcinogenicity in rats, there
was no evidence of genotoxicity for tebuconazole, and tumors were only
seen at a high and excessively toxic dose in mice, EPA concluded that the
chronic RfD would be protective of any potential carcinogenic effect. The
chronic RfD value is 0.029 mg/kg/day which is approximately 9,600 fold
lower than the dose that would induce liver tumors (279 mg/kg/day).
----------------------------------------------------------------------------------------------------------------
UFA = extrapolation from animal to human (interspecies). UFH = potential variation in sensitivity among members
of the human population (intraspecies). UFL = use of a LOAEL to extrapolate a NOAEL. UFS = use of a short-term
study for long-term risk assessment. UFDB = to account for the absence of data or other data deficiency. 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. DAF = dermal absorption factor.
C. Exposure Assessment
1. Dietary exposure from food and feed uses. In evaluating dietary
exposure to tebuconazole, EPA considered exposure under the petitioned-
for tolerances as well as all existing tebuconazole tolerances in 40
CFR 180.474. EPA assessed dietary exposures from tebuconazole 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.
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, anticipated residues
for bananas, grapes, raisins, nectarines, peaches, and peanut butter
were derived using the 2002-2006 USDA Pesticide Data Program (PDP)
monitoring data. Anticipated residues for all other registered food
commodities were based on field trial data. For uses associated with PP
0F7792, 100 percent crop treated (PCT) was assumed. DEEM (ver. 7.81)
default processing factors were assumed for processed commodities
associated with petition 0F7792. For several other uses EPA used PCT
data as specified in Unit III.C.1.iv.
ii. Chronic exposure. In conducting the chronic dietary exposure
assessment, EPA used the same data sources as stated in Unit III. C. 1.
i. for acute exposure.
iii. Cancer. As explained in Unit III.B., the chronic risk
assessment is considered to be protective of any cancer effects;
therefore, a separate quantitative cancer dietary risk assessment was
not conducted.
iv. Anticipated residue and PCT information. 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.
Section 408(b)(2)(F) of FFDCA states that the Agency may use data
on the actual percent of food treated for assessing chronic dietary
risk only if:
Condition a: 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 the pesticide residue.
Condition b: The exposure estimate does not underestimate
exposure for any significant subpopulation group.
Condition c: 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 FFDCA section 408(b)(2)(F), EPA may require
registrants to submit data on PCT.
The Agency estimated the PCT for existing uses as follows:
Grapes: 25% acute assessment, 15% chronic assessment; grape,
raisin: 25% acute assessment, 15% chronic assessment; nectarine: 25%
acute assessment, 20% chronic assessment; peach: 20% acute assessment,
15% chronic assessment; and peanuts: 45% acute assessment, 15% chronic
assessment.
In most cases, EPA uses available data from United States
Department of Agriculture/National Agricultural Statistics Service
(USDA/NASS), proprietary market surveys, and the National Pesticide Use
Database for the chemical/crop combination for the most
[[Page 54130]]
recent 6-7 years. EPA uses an average PCT for chronic dietary risk
analysis. The average PCT figure for each existing use is derived by
combining available public and private market survey data for that use,
averaging across all observations, and rounding to the nearest 5%,
except for those situations in which the average PCT is less than one.
In those cases, 1% is used as the average PCT and 2.5% is used as the
maximum PCT. EPA uses a maximum PCT for acute dietary risk analysis.
The maximum PCT figure is the highest observed maximum value reported
within the recent 6 years of available public and private market survey
data for the existing use and rounded up to the nearest multiple of 5%.
The Agency also used PCT information for tebuconazole on the
following recently approved uses: Apples, apricots, cherries
(preharvest), sweetcorn, hops, plums, and turnips. The PCT for each
crop is as follows: Apples, acute assessment 44%, chronic assessment
41%; Apricots, acute assessment 56%, chronic assessment 43%; Cherries,
preharvest, acute assessment 42%, chronic assessment 37%; Corn, sweet,
acute assessment 22%, chronic assessment 14%; Hops, acute assessment
64%, chronic assessment 64%; Plum, acute assessment 26%, chronic
assessment 24%; Turnip, acute assessment 68%, chronic assessment 44%.
EPA estimates PCT for a new pesticide use by assuming that its actual
PCT during the initial five years of use on a specific use site will
not exceed the recent PCT of the market leader (i.e. ,the one with the
greatest PCT) on that site. An average market leader PCT, based on
three recent surveys of pesticide usage, if available, is used for
chronic risk assessment, while the maximum PCT from the same three
recent surveys, if available, is used for acute risk assessment. The
average and maximum market leader PCTs may each be based on one or two
surveys if three are not available. Comparisons are only made among
pesticides of the same pesticide type (i.e., the leading fungicide on
the use site is selected for comparison with the new fungicide). The
market leader PCTs used to determine the average and the maximum may be
each for the same pesticide or for different pesticides since the same
or different pesticides may dominate for each year. Typically, EPA uses
USDA/NASS as the source for raw PCT data because it is publicly
available. When a specific use site is not surveyed by USDA/NASS, EPA
uses other sources including proprietary data.
An estimated PCT, based on the average PCT of the market leaders,
is appropriate for use in chronic dietary risk assessment, and an
estimated projected percent crop treated (PPCT), based on the maximum
PCT of the market leaders, is appropriate for use in acute dietary risk
assessment. This method of estimating PCTs for a new use of a
registered pesticide or a new pesticide produces high-end estimates
that are unlikely, in most cases, to be exceeded during the initial
five years of actual use. Predominant factors that bear on whether the
PCTs could be exceeded may include PCTs of similar chemistries, pests
controlled by alternatives, pest prevalence in the market and other
factors. Based on these factors, EPA has adjusted upward the estimates
for three crops: Cherries post-harvest, hops and turnip greens.
The Agency believes that the three conditions discussed in Unit
III.C.1.iv. have been met. With respect to Condition a, PCT estimates
are derived from Federal and private market survey data, which are
reliable and have a valid basis. The Agency is reasonably certain that
the percentage of the food treated is not likely to be an
underestimation. As to Conditions b and c, 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 reliable information on the regional consumption of
food to which tebuconazole may be applied in a particular area.
2. Dietary exposure from drinking water. The Agency used screening
level water exposure models in the dietary exposure analysis and risk
assessment for tebuconazole in drinking water. These simulation models
take into account data on the physical, chemical, and fate/transport
characteristics of tebuconazole. Further information regarding EPA
drinking water models used in pesticide exposure assessment can be
found at https://www.epa.gov/oppefed1/models/water/index.htm.
Surface water estimated drinking water concentrations (EDWCs)
resulting from the Pesticide Root Zone Model/Exposure Analysis Modeling
System (PRZM/EXAMS) were used in the dietary assessment, since they
were higher than the EDWCs resulting from the Screening Concentration
in Ground Water (SCI GROW). A distribution of 30-year daily surface
water concentrations was estimated for the EDWCs of tebuconazole for
acute exposures. The EDWC for chronic, noncancer exposure is estimated
to be 59.0 [mu]g/L for surface 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).
Tebuconazole has currently registered uses that could result in
residential exposures. Short-term dermal and inhalation exposures are
possible for residential adult handlers mixing, loading, and applying
tebuconazole products outdoors to ornamental plants. Short- and
intermediate-term dermal postapplication exposures are also possible to
golfers from treated golf turf and to adults and children from contact
to treated wood structures. Children may also be exposed via the
incidental oral route when playing on treated wood structures. Long-
term exposure is not expected. As a result, risk assessments have been
completed for residential handler scenarios as well as residential
post-application scenarios.
Further information regarding EPA standard assumptions and generic
inputs for residential exposures may be found at https://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.''
Tebuconazole is a member of the triazoles (and more specifically,
triazole-derivative fungicides). Although triazoles 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 triazole-
[[Page 54131]]
derivative fungicides, however, a variable pattern of toxicological
responses is found: Some are hepatotoxic and hepatocarcinogenic in
mice; some induce thyroid tumors in rats; and some induce
developmental, reproductive, and neurological effects in rodents.
Furthermore, the triazoles 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
triazole-derivative fungicides share common mechanisms of toxicity and
EPA is not following a cumulative risk approach based on a common
mechanism of toxicity for the triazole-derivative fungicides. 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 https://www.epa.gov/pesticides/cumulative.
However, the triazole-derivative fungicides can form the common
metabolites 1,2,4-triazole and conjugated triazole metabolites. To
support existing tolerances and to establish new tolerances for
triazole-derivative fungicides, including tebuconazole, 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-derivative 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 at https://www.regulations.gov, docket
ID number EPA-HQ-OPP-2011-0120 in the document entitled ``Common
Triazole Metabolites: Updated Dietary (Food + Water) Exposure and Risk
Assessment to Address the Amended Metconazole Section 3 Registration to
Add Uses on Tuberous and Corm Vegetables (Group 1C) and Bushberry
Subgroup 13-07B''. This document updates another EPA risk assessment on
triazole-derived pesticides which can be found in the reregistration
docket for propiconazole at https://www.regulations.gov, docket 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. The toxicity database for
tebuconazole includes prenatal developmental toxicity studies in three
species (mouse, rat, and rabbit), a reproductive toxicity study in
rats, acute and subchronic neurotoxicity studies in rats, and a
developmental neurotoxicity study in rats. The data from prenatal
developmental toxicity studies in mice and a developmental
neurotoxicity study in rats indicated an increased quantitative and
qualitative susceptibility following in utero exposure to tebuconazole.
The NOAELs/LOAELs for developmental toxicity in these studies were
found at dose levels less than those that induce maternal toxicity or
in the presence of slight maternal toxicity. There was no indication of
increased quantitative susceptibility in the rat and rabbit
developmental toxicity studies, the NOAELs for developmental toxicity
were comparable to or higher than the NOAELs for maternal toxicity. In
all three species, however, there was indication of increased
qualitative susceptibility. For most studies, minimal maternal toxicity
was seen at the LOAEL (consisting of increases in hematological
findings in mice, increased liver weights in rabbits and rats, and
decreased body weight gain/food consumption in rats) and did not
increase substantially in severity at higher doses; however, there was
more concern for the developmental effects at each LOAEL which included
increases in runts, increased fetal loss, and malformations in mice,
increased skeletal variations in rats, and increased fetal loss and
frank malformations in rabbits. Additionally, more severe developmental
effects (including frank malformations) were seen at higher doses in
mice, rats and rabbits. In the developmental neurotoxicity study,
maternal toxicity was seen only at the high dose (decreased body
weights, body weight gains, and food consumption, prolonged gestation
with mortality, and increased number of dead fetuses), while offspring
toxicity (including decreases in body weight, brain weight, brain
measurements and functional activities) was seen at all doses.
Available data indicated greater sensitivity of the developing
organism to exposure to tebuconazole, as demonstrated by increases in
qualitative sensitivity in prenatal developmental toxicity studies in
rats, mice, and rabbits, and by increases in both qualitative and
quantitative sensitivity in the developmental neurotoxicity study in
rats with tebuconazole. However, the degree of concern is low because
the toxic endpoints in the prenatal developmental toxicity studies were
well characterized with clear NOAELs established and the most sensitive
endpoint, which is found in the developmental neurotoxicity study, has
been used for overall risk assessments. Therefore, there are no
residual uncertainties for pre- and/or postnatal susceptibility.
3. Conclusion. The Agency has determined that reliable data show
the safety of infants and children would be adequately protected if the
FQPA SF were reduced to 3x for all potential exposure scenarios. The
decision is based on the following findings:
i. The toxicity database for tebuconazole is complete with the
exception of an immunotoxicity study requirement under the new 40 CFR
part 158 guidelines for toxicity data. The available guideline studies
do not suggest that tebuconazole directly targets the immune system. A
peer-reviewed developmental neurotoxicity/immunotoxicity literature
study found in high dose groups (60 mg/kg/day) increased spleen weights
and alterations in splenic lymphocyte subpopulations. At the same dose
there were no effects seen in the T-cell dependent antibody response to
sheep red blood cells (SRBC) and natural killer (NK) cell activity
indicating that tebuconazole did not alter the functional immune
response in rats. Based on guideline and open literature, the overall
weight of evidence suggests that tebuconazole does not directly target
the immune system. The Agency does not believe that conducting a
functional immunotoxicity study will result in a lower POD than
currently used for overall risk assessment; therefore, a
[[Page 54132]]
database uncertainty factor (UFDB) is not needed to account for the
lack of the study.
ii. Although there is qualitative evidence of increased
susceptibility in the prenatal developmental studies in rats, the
Agency did not identify any residual uncertainties after establishing
toxicity endpoints and traditional UFs to be used in the risk
assessment of tebuconazole. The degree of concern for residual
uncertainties for prenatal and/or postnatal toxicity is low.
iii. A 3x FQPA safety factor is needed to address the failure to
achieve a NOAEL in the developmental neurotoxicity (DNT) study.
Reduction of the FQPA safety factor from 10x to 3x is based on a
Benchmark Dose (BMD) analysis of the datasets relevant to the adverse
offspring effects (decreased body weight, decreases in absolute brain
weights, changes in brain morphometric parameters, and decreases in
motor activity) seen at the LOAEL in the DNT study. The BMD analysis
models or estimates the dose (BMD) associated with a specified measure
or change (e.g. a dose representing a 10% change) of a biological
effect over the control. All of the BMDLs (the lower limit of a one-
sided 95% confidence interval on the BMD) modeled successfully on
statistically significant effects are 1-2x lower than the LOAEL. The
results indicate that the use of the FQPA safety factor of 3x would not
underestimate risk. Using a 3x FQPA safety factor in the risk
assessment (8.8 mg/kg/day / 3x = 2.9 mg/kg/day) is further supported by
the NOAELs established in other studies in the tebuconazole toxicity
database [i.e., 3 and 2.9 mg/kg/day, from a DNT study in mice and a
chronic toxicity study in dogs, respectively (respective LOAELs 10 and
4.5 mg/kg/day)].
iv. There are no residual uncertainties identified in the exposure
databases. Although the acute and chronic food exposure assessments are
refined, EPA believes that the assessments are based on reliable data
and will not underestimate exposure/risk. The drinking water estimates
were derived from conservative screening models. The residential
exposure assessment utilizes reasonable high-end variables set out in
EPA's Occupational/Residential Exposure SOPs (Standard Operating
Procedures). The aggregate assessment is based upon reasonable worst-
case residential assumptions, and is also not likely to underestimate
exposure/risk to any subpopulation, including those comprised of
infants and children.
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.
1. Acute risk. Using the exposure assumptions discussed in this
unit for acute exposure, the acute dietary exposure from food and water
to tebuconazole will occupy 33% of the aPAD for the U.S. population and
62% of the aPAD for the population group (children 3-5 years old)
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
tebuconazole from food and water will utilize 8.8% of the cPAD for the
U.S. population and 16% of the cPAD for the most highly exposed
population group (all infants (< 1 year old).
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). Tebuconazole
is currently registered for uses 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 tebuconazole.
Using the exposure assumptions described in this unit for short
term exposures, EPA has concluded that the short-term aggregate MOE
from dietary exposure (food + drinking water) and non-occupational/
residential handler exposure for adults using a hose-end sprayer on
ornamentals is 370. The short-term aggregate MOE from dietary exposure
and exposure from golfing is 1,900. The likelihood of a residential
handler treating ornamentals with tebuconazole and then playing golf on
a tebuconazole-treated course is considered low; therefore, each
scenario is considered separately with background dietary exposure. The
short-term aggregate MOE to children from dietary exposure and exposure
from wood surfaces treated at the above ground use rate is 470. The
short-term aggregate MOE to children from dietary exposure and exposure
to wood surfaces treated at the below ground use rate is 220. The
combined and aggregate MOEs for wood treated for below ground uses are
lower than the target MOE (300) and thus indicate a potential risk of
concern. However, the combined MOE for wood treated for above-ground
uses is not lower than the target MOE, and therefore is not of concern.
Exposure to above-ground wood is expected to more closely represent
actual exposures to children. Frequency of exposures to above-ground
wood should greatly exceed any exposures to below-ground wood, and
exposures to below ground wood would be minimal, or negligible. It is
unrealistic to expect a full duration of exposure to below ground wood.
Therefore, EPA concludes that there is not a concern for short-term
aggregate risk.
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). Tebuconazole is currently registered for uses that could result
in intermediate-term residential exposure, and the Agency has
determined that it is appropriate to aggregate chronic exposure through
food and water with intermediate-term residential exposures to
tebuconazole. Since the POD, relevant exposure scenarios and exposure
assumptions used for intermediate-term aggregate risk assessments are
the same as those used for short-term aggregate risk assessments, the
short-term aggregate risk assessments represent and are protective of
both short and intermediate-term exposure durations.
5. Aggregate cancer risk for U.S. population. As discussed in this
unit, the chronic risk assessment is considered to be protective of any
cancer effects; therefore, because the chronic risk assessment
indicates exposure is lower than the cPAD, tebuconazole does not pose a
cancer risk of concern.
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 tebuconazole residues.
IV. Other Considerations
A. Analytical Enforcement Methodology
Adequate gas chromatography/nitrogen phosphorous detector (GC/NPD)
and liquid chromatography/mass
[[Page 54133]]
spectrometry/mass spectrometry (LC/MS/MS) methods are available for
both collecting and enforcing tolerances for tebuconazole and its
metabolites in plant commodities, livestock matrices and processing
studies. The methods have been adequately validated by an independent
laboratory in conjunction with a previous petition. 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: residuemethods@epa.gov.
B. International Residue Limits
Codex and Canada have established maximum residue limits (MRLs) for
tebuconazole in/on a variety of plant and livestock commodities. The
tolerance expression for tebuconazole is harmonized between U.S.,
Codex, and Canada. The proposed tolerances will harmonize established
U.S. tolerances on oat and wheat with current Canadian MRLs.
There are currently no Codex MRLs for wheat and oats.
C. Revisions to Petitioned-For Tolerances
The Agency concluded that residues of tebuconazole do not
concentrate in wheat bran, flour or middlings, but do concentrate in
shorts and germ (2.5X). As a result, a tolerance in/on wheat, shorts
and wheat, germ, each at 0.20 ppm (highest average field trial (HAFT)
value = 0.08 ppm), is required.
V. Conclusion
Therefore, tolerances are established for residues of tebuconazole,
in or on wheat, grain, and oat, grain at 0.15 ppm and wheat, shorts,
and wheat, germ at 0.20 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: August 17, 2011.
Lois Rossi,
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 180.474, paragraph (a)(1) is amended by:
0
i. Revising the introductory text;
0
ii. Revising the entries for ``oat, grain'' and ``wheat, grain'' in the
table; and
0
iii. Alphabetically adding entries for ``wheat, shorts'' and ``wheat,
germ'' to the table.
The amendments read as follows:
Sec. 180.474 Tebuconazole; tolerances for residues.
(a) * * *
(1) Tolerances are established for residues of tebuconazole, alpha-
[2-(4-chlorophenyl)ethyl]-alpha-(1,1-dimethylethyl)-1H-1,2,4-triazole-
1-ethanol, including its metabolites and degradates, in or on the
commodities in the table below. Compliance with the tolerance levels
specified below is to be determined by measuring only tebuconazole
[[alpha]-[2-(4-chlorophenyl) ethyl]-[alpha]-(1,1-dimethylethyl)-1H-
1,2,4-triazole-1-ethanol], in or on the commodity.
------------------------------------------------------------------------
Parts
Commodity per
million
------------------------------------------------------------------------
* * * * *
Oat, grain................................................... 0.15
Wheat, grain................................................. 0.15
Wheat, shorts................................................ 0.20
Wheat, germ.................................................. 0.20
* * * * *
------------------------------------------------------------------------
* * * * *
[FR Doc. 2011-22138 Filed 8-30-11; 8:45 am]
BILLING CODE 6560-50-P