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Tebuconazole; Pesticide Tolerances for Emergency Exemptions
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
[Federal Register: December 2, 1998 (Volume 63, Number 231)]
[Rules and Regulations]
[Page 66449-66456]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr02de98-18]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-300745; FRL-6036-3]
RIN 2070-AB78
Tebuconazole; Pesticide Tolerances for Emergency Exemptions
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes a time-limited tolerance for
residues of tebuconazole in or on hops. This action is in response to
EPA's granting of an emergency exemption under section 18 of the
Federal Insecticide, Fungicide, and Rodenticide Act authorizing use of
the pesticide on hops. This regulation establishes a maximum
permissible level for residues of tebuconazole in this food commodity
pursuant to section 408(l)(6) of the Federal Food, Drug, and Cosmetic
Act, as amended by the Food Quality Protection Act of 1996. The
tolerance will expire and is revoked on December 31, 2,000.
DATES: This regulation is effective December 2, 1998. Objections and
requests for hearings must be received by EPA on or before February 1,
1999.
ADDRESSES: Written objections and hearing requests, identified by the
docket control number, [OPP-300745], must be submitted to: Hearing
Clerk (1900), Environmental Protection Agency, Rm. M3708, 401 M St.,
SW., Washington, DC 20460. Fees accompanying objections and hearing
requests shall be labeled ``Tolerance Petition Fees'' and forwarded to:
EPA Headquarters Accounting Operations Branch, OPP (Tolerance Fees),
P.O. Box 360277M, Pittsburgh, PA 15251. A copy of any objections and
hearing requests filed with the Hearing Clerk identified by the docket
control number, [OPP-300745], must also be submitted to: Public
Information and Records Integrity Branch, Information Resources and
Services Division (7502C), Office of Pesticide Programs, Environmental
Protection Agency, 401 M St., SW., Washington, DC 20460. In person,
bring a copy of objections and hearing requests to Rm. 119, Crystal
Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA.
A copy of objections and hearing requests filed with the Hearing
Clerk may also be submitted electronically by sending electronic mail
(e-mail) to: opp-docket@epamail.epa.gov. Copies of objections and
hearing requests must be submitted as an ASCII file avoiding the use of
special characters and any form of encryption. Copies of objections and
hearing requests will also be accepted on disks in WordPerfect 5.1/6.1
file format or ASCII file format. All copies of objections and hearing
requests in electronic form must be identified by the docket control
number [OPP-300745]. No Confidential Business Information (CBI) should
be submitted through e-mail. Electronic copies of objections and
hearing requests on this rule may be filed online at many Federal
Depository Libraries.
FOR FURTHER INFORMATION CONTACT: By mail: Barbara A. Madden,
Registration Division 7505C, Office of Pesticide Programs,
Environmental Protection Agency, 401 M St., SW., Washington, DC 20460.
Office location, telephone number, and e-mail address: Crystal Mall #2,
1921 Jefferson Davis Hwy., Arlington, VA, (703) 305-6463, e-mail:
madden.barbara@epamail.epa.gov.
SUPPLEMENTARY INFORMATION: EPA, on its own initiative, pursuant to
sections 408(e) and (l)(6) of the Federal Food, Drug, and Cosmetic Act
(FFDCA), 21 U.S.C. 346a(e) and (l)(6), is establishing a tolerance for
residues of the fungicide tebuconazole in or on hops at 4.0 part per
million (ppm). This tolerance will expire and is revoked on December
31, 2,000. EPA will publish a document in the Federal Register to
remove the revoked tolerance from the Code of Federal Regulations.
I. Background and Statutory Authority
The Food Quality Protection Act of 1996 (FQPA) (Pub. L. 104-170)
was signed into law August 3, 1996. FQPA amends both the Federal Food,
Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 301 et seq., and the Federal
Insecticide, Fungicide, and Rodenticide Act (FIFRA), 7 U.S.C. 136 et
seq. The FQPA amendments went into effect immediately. Among other
things, FQPA amends FFDCA to bring all EPA pesticide tolerance-setting
activities under a new section 408 with a new
[[Page 66450]]
safety standard and new procedures. These activities are described
below and discussed in greater detail in the final rule establishing
the time-limited tolerance associatedwith the emergency exemption for
use of propiconazole on sorghum (61 FR 58135, November 13, 1996)(FRL-
5572-9).
New section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a
tolerance (the legal limit for a pesticide chemical residue in or on a
food) only if EPA determines that the tolerance is ``safe.'' Section
408(b)(2)(A)(ii) defines ``safe'' to mean that ``there is a reasonable
certainty that no harm will result from aggregate exposure to the
pesticide chemical residue, including all anticipated dietary exposures
and all other exposures for which there is reliable information.'' This
includes exposure through drinking water and in residential settings,
but does not include occupational exposure. Section 408(b)(2)(C)
requires EPA to give special consideration to exposure of infants and
children to the pesticide chemical residue in establishing a tolerance
and to ``ensure that there is a reasonable certainty that no harm will
result to infants and children from aggregate exposure to the pesticide
chemical residue....''
Section 18 of FIFRA authorizes EPA to exempt any Federal or State
agency from any provision of FIFRA, if EPA determines that ``emergency
conditions exist which require such exemption.'' This provision was not
amended by FQPA. EPA has established regulations governing such
emergency exemptions in 40 CFR part 166.
Section 408(l)(6) of the FFDCA requires EPA to establish a time-
limited tolerance or exemption from the requirement for a tolerance for
pesticide chemical residues in food that will result from the use of a
pesticide under an emergency exemption granted by EPA under section 18
of FIFRA. Such tolerances can be established without providing notice
or period for public comment.
Because decisions on section 18-related tolerances must proceed
before EPA reaches closure on several policy issues relating to
interpretation and implementation of the FQPA, EPA does not intend for
its actions on such tolerances to set binding precedents for the
application of section 408 and the new safety standard to other
tolerances and exemptions.
II. Emergency Exemption for tebuconazole on hops and FFDCA
Tolerances
The States of Idaho, Oregon, and Washington availed themselves of
the authority to declare a crisis exemption to use tebuconazole for
control of Powdery mildew (Sphaerotheca macularis) on hops. Powdery
mildew is a serious hop disease in many hop growing areas in the world.
The elimination of commercial hop production in New York during the
early part of this century is largely blamed on this disease. Since
this disease has not been observed in the Pacific Northwest until very
recently, no effective fungicides are registered for use on hops to
control it. Sulfur is the only pesticide available, but does not
provide effective control. The pathogen is airborne and spreads
quickly, primarily during the months of July and August, which are
critical to hop production. EPA has authorized under FIFRA section 18
the use of tebuconazole on hops for control of Powdery mildew
(Sphaerotheca macularis) in Idaho, Oregon, and Washington. After having
reviewed the submission, EPA concurs that emergency conditions exist
for this state.
As part of its assessment of this emergency exemption, EPA assessed
the potential risks presented by residues of tebuconazole in or on
hops. In doing so, EPA considered the safety standard in FFDCA section
408(b)(2), and EPA decided that the necessary tolerance under FFDCA
section 408(l)(6) would be consistent with the safety standard and with
FIFRA section 18. Consistent with the need to move quickly on the
emergency exemption in order to address an urgent non-routine situation
and to ensure that the resulting food is safe and lawful, EPA is
issuing this tolerance without notice and opportunity for public
comment under section 408(e), as provided in section 408(l)(6).
Although this tolerance will expire and is revoked on December 31,
2,000, under FFDCA section 408(l)(5), residues of the pesticide not in
excess of the amounts specified in the tolerance remaining in or on
hops after that date will not be unlawful, provided the pesticide is
applied in a manner that was lawful under FIFRA, and the residues do
not exceed a level that was authorized by this tolerance at the time of
that application. EPA will take action to revoke this tolerance earlier
if any experience with, scientific data on, or other relevant
information on this pesticide indicate that the residues are not safe.
Because this tolerance is being approved under emergency conditions
EPA has not made any decisions about whether tebuconazole meets EPA's
registration requirements for use on hops or whether a permanent
tolerance for this use would be appropriate. Under these circumstances,
EPA does not believe that this tolerance serves as a basis for
registration of tebuconazole by a State for special local needs under
FIFRA section 24(c). Nor does this tolerance serve as the basis for any
State other than Idaho, Oregon, and Washington to use this pesticide on
this crop under section 18 of FIFRA without following all provisions of
EPA's regulations implementing section 18 as identified in 40 CFR part
166. For additional information regarding the emergency exemption for
tebuconazole, contact the Agency's Registration Division at the address
provided above.
III. Aggregate Risk Assessment and Determination of Safety
EPA performs a number of analyses to determine the risks from
aggregate exposure to pesticide residues. For further discussion of the
regulatory requirements of section 408 and a complete description of
the risk assessment process, see the Final Rule on Bifenthrin Pesticide
Tolerances (62 FR 62961, November 26, 1997)(FRL-5754-7) .
Consistent with section 408(b)(2)(D), EPA has reviewed the
available scientific data and other relevant information in support of
this action EPA has sufficient data to assess the hazards of
tebuconazole and to make a determination on aggregate exposure,
consistent with section 408(b)(2), for a time-limited tolerance for
residues of tebuconazole on hops at 4.0 ppm. EPA's assessment of the
dietary exposures and risks associated with establishing the tolerance
follows.
A. Toxicological Profile
EPA has evaluated the available toxicity data and considered its
validity, completeness, and reliability as well as the relationship of
the results of the studies to human risk. EPA has also considered
available information concerning the variability of the sensitivities
of major identifiable subgroups of consumers, including infants and
children. The nature of the toxic effects caused by tebuconazole are
discussed below.
1. Acute toxicity. The acute reference dose (acute RfD) of 0.1
milligrams/kilogram/day (mg/kg/day) for tebuconazole was established
based on a developmental toxicity study in mice with a No-Observed-
Adverse-Effect-Level (NOAEL) of 10 mg/kg/day for developmental
toxicity. At the Lowest-Observed-Adverse-Effect-Level (LOAEL) of 30 mg/
kg/day, an increased incidence of runts (fetuses weighing less than 1.3
gram) were observed. An uncertainty
[[Page 66451]]
factor of 100 (10X for inter-species extrapolation and 10X for intra-
species variability) was applied to the NOAEL of 10 mg/kg/day to
calculate the acute RfD of 0.1 mg/kg/day. EPA has determined that the
10X factor to account for enhanced susceptibility of infants and
children (as required by FQPA) should be retained. This determination
is based on the results of the developmental toxicity study in mice
used to establish the acute RfD, other developmental toxicity studies
in mice, rats and rabbits and the structural relationship of
tebuconazole to several other triazole pesticides which also have been
shown to induce developmental toxicity in rats and/or rabbits. For
acute dietary exposure, EPA determined that the 10X safety factor is
applicable to the subpopulations females (13+ years old), as well as
infants and children because the effects seen were developmental and
are presumed to occur following ``acute'' exposures. For subpopulations
other than females (13+ years old), infants and children, a
toxicological endpoint was not identified. Application of the 10X
safety factor for enhanced susceptibility of infants and children to
the acute RfD of 0.1 mg/kg/day results in an acceptable acute dietary
exposure (food plus water) of 10% or less of the acute RfD.
2. Short- and intermediate-term toxicity. Toxicological endpoints
for short- or intermediate-term dermal toxicity were not identified.
Adverse systemic effects were not observed in dermal developmental
toxicity studies in mice or rats at the limit dose of 1,000 mg/kg/day
or in a 21-day dermal toxicity study in rabbits at the limit dose of
1,000 mg/kg/day. Therefore, risk assessments for short- or
intermediate-term dermal exposure were not conducted.
A NOAEL of 0.0106 mg/liter/day (equivalent to 2.9 mg/kg/day) was
identified as the toxicological endpoint for short- and intermediate-
term (and chronic) inhalation toxicity based on a 21-day inhalation
toxicity study in rats. At the LOAEL of 0.1558 mg/liter/day,
piloerection and increased liver O-demethylase and N-demethylase
activity were observed in both males and females. EPA determined that
the 10X safety factor to account for enhanced susceptibility of infants
and children (as required by FQPA) is not applicable for inhalation
toxicity for the currently registered residential exposures to
tebuconazole. A Margin of Exposure (MOE) of 100 or more for short- or
intermediate-term non-dietary risk is acceptable for all
subpopulations.
3. Chronic toxicity. EPA has established a chronic RfD for
tebuconazole at 0.03 mg/kg/day. This RfD is based on a 1-year chronic
feeding study in dogs in which the NOAEL was 100 ppm (2.96 mg/kg/day in
males and 2.94 mg/kg/day in females) and the LOAEL was 150 ppm (4.39
mg/kg/day in males and 4.45 mg/kg/day in females), based on
histopathological changes in the adrenal gland (hypertrophy of the zona
fasciculata and fatty changes in the zona glomerulosa in both sexes and
lipid hyperplasia in the cortex in males). An uncertainty factor of 100
was used to account for inter-species extrapolation and intra-species
variability. EPA determined that the 10X factor for enhanced
susceptibility of infants and children (as required by FQPA) is not
applicable for chronic dietary exposure. A chronic dietary exposure
(food plus water) of 100% or less of the Chronic RfD is acceptable for
all subpopulations.
4. Carcinogenicity. Tebuconazole is classified as a Group C
(possible human) carcinogen. This decision was primarily based on
results in a 91-week carcinogenicity study in mice in which the
following effects were observed:
i. A statistically significant increase in the incidence of
hepatocellular adenomas, carcinomas and combined adenomas/carcinomas in
male mice at the highest dose tested (279 mg/kg/day).
ii. A statistically significant increase in the incidence of
hepatocellular carcinomas and combined adenomas/carcinomas in female
mice at the highest dose tested (366 mg/kg/day).
In addition, tebuconazole is structurally related to several other
triazole pesticides that produce similar liver tumors in mice. For the
purpose of carcinogenic risk assessment, the RfD methodology is used to
estimate human risk.
B. Exposures and Risks
1. From food and feed uses. Tolerances have been established (40
CFR 180.474) for the residues of tebuconazole, in or on a variety of
raw agricultural commodities. Tolerances have been established for milk
and meat byproducts in connection with use of tebuconazole under a
previous section 18. Risk assessments were conducted by EPA to assess
dietary exposures and risks from tebuconazole as follows:
i. Acute exposure and risk. Acute dietary risk assessments are
performed for a food-use pesticide if a toxicological study has
indicated the possibility of an effect of concern occurring as a result
of a 1 day or single exposure. An acute dietary endpoint of concern was
identified for subpopulations females (13+ years old), as well as
infants and children. For acute dietary exposure, EPA determined that
the 10X safety factor for enhanced susceptibility of infants and
children (as required by FQPA) is applicable to all of these
subpopulations. Application of the 10X safety factor for enhanced
susceptibility of infants and children to the acute RfD of 0.1 mg/kg/
day results in an acceptable acute dietary exposure (food plus water)
of 10% or less of the acute RfD.
An acute dietary (food only) probablistic risk analysis submitted
in conjunction with another action was used to estimate acute dietary
risk. The following assumptions were utilized in the Monte Carlo
analysis: (a) Percent crop treated data were used for all commodities;
(b) maximum residue levels from crop field trials for single serving
commodities such as bananas and peaches were utilized; (c) average
residue levels from crop field trials were used for blended commodities
such as fruit juices, grains and oils; (d) anticipated residue levels
for ruminant commodities were calculated using a livestock diet
constructed using anticipated residue levels for livestock feed items.
This analysis should be considered highly refined. This analysis was
run with 2,000 iterations. The results of the Monte Carlo analysis
indicate that the percent of acute RfD for all children and infants
subgroups as well as females 13+ years old are all below 10% of the
RfD: nursing infants (< 1 year old), 7%; non-nursing infants (< 1 year
old), 7%; children (1 to 6 years old) 9%, children (7 to 12 years old)
3%; all infants (< 1 year old), 7%; females (13 years plus old), 3%.
ii. Chronic exposure and risk. The Agency conducted a chronic
dietary exposure analysis and risk assessment. The analysis evaluated
individual food consumption as reported by respondents in the USDA
1977-78 Nationwide Food Consumption Survey (NFCS) and accumulates
exposure to the chemical for each commodity. In conducting the chronic
dietary risk assessment, the Agency made very conservative assumptions
(100% of hops, pistachios and wheat and all other commodities having
tebuconazole tolerances will contain residues and those residues will
be at tolerance level) which results in an overestimation of human
dietary exposure. Thus, in making a safety determination for these
tolerances, the Agency is taking into account this conservative
exposure assessment.
The existing tebuconazole tolerances (published, pending, and
including the necessary section 18 tolerance(s)) result
[[Page 66452]]
in a Theoretical Maximum Residue Contribution (TMRC) that is equivalent
to percentages of the RfD below 100% for all subgroups (i.e., U.S.
population, 11% and non-nursing infants (< 1 year old), the most highly
exposed subgroup, 37%).
2. From drinking water. Based on present data in the Agency files,
tebuconazole is persistent and relatively immobile. There are no
established Maximum Contaminant Level or health advisory levels for
residues of tebuconazole in drinking water. Monitoring data for
residues of tebuconazole in surface and ground water are not available.
Tebuconazole is not included in the Pesticides in Ground Water Database
(USEPA, 1992), and it was not an analyte in the National Pesticide
Survey (USEPA, 1990).
EPA estimated exposure for tebuconazole for both surface and ground
water based on available modeling. Environmental concentrations for
surface water were estimated using modeling from GENEEC (Generic
Estimated Environmental Concentration). For surface water, the maximum
concentrations were used for acute risk calculations, the annual means
(1-10 years old) for chronic risk calculations. Current Agency policy
allows that a factor of 3 be applied to GENEEC model values when
determining whether or not a level of concern has been exceeded. If the
GENEEC model value is <gr-thn-eq> 3 times the drinking water level of
concern (DWLOC), the pesticide is considered to have passed the screen.
Acute and chronic ground water concentrations were estimated using the
SCI-GROW (Screening Concentration in Ground Water) model. For the
purposes of the screening level assessment, the maximum and average
annual concentrations in ground water are not believed to vary
significantly. DWLOCs will be compared directly to values.
i. Acute exposure and risk. DWLOCs were calculated for acute
exposures to tebuconazole in surface and ground water for females 13+
years old and children (1-6 years old). Relative to an acute toxicity
endpoint, the acute dietary food exposure (from the probablistic
analysis) was subtracted from the ratio of the acute NOAEL to the
appropriate percentage acute RfD to obtain the acceptable acute
exposure to tebuconazole in drinking water. DWLOCs were then calculated
from this acceptable exposure using default body weights (60 kg for
females and 10 kg for children) and drinking water consumption figures
(2 liters for females and 1 liter for children). Based on these
calculations EPA's DWLOC for acute dietary risk is 14 parts per billion
(ppb) for children (1-6 years old) and 200 ppb for females 13+ years
old.
Maximum concentrations of tebuconazole in surface and ground water
are estimated to be 14 ppb and 0.3 ppb, respectively. The maximum
estimated concentrations of tebuconazole in surface and ground water
are less than EPA's levels of concern for acute exposure in drinking
water for the females 13+ and children.
ii. Chronic exposure and risk. EPA has calculated DWLOCs for
chronic exposures to tebuconazole in surface and ground water. To
calculate the DWLOC for chronic exposures relative to a chronic
toxicity endpoint, the chronic dietary food exposure was subtracted
from the chronic RfD (0.03 mg/kg/day) to obtain the acceptable chronic
exposure to tebuconazole in drinking water. DWLOCs were then calculated
from this exposure using default body weights (70 kg for U.S.
population, 60 kg for females and 10 kg for children) and drinking
water consumption figures (2 liters U.S. population and females and 1
liter children). Based on these calculations EPA's DWLOCs for chronic
risk are 950 ppb for the U.S. population, 780 ppb for females and 190
ppb for non-nursing infants (< 1 year old).
Estimated annual average concentrations of tebuconazole in surface
water and ground water are 10 ppb and 0.3 ppb, respectively. The
estimated annual average concentrations of tebuconazole in surface and
ground water are less than EPA's levels of concern for chronic exposure
in drinking water.
3. From non-dietary exposure. No short- or intermediate-term dermal
toxicological endpoints were identified. Tebuconazole's registered
residential uses are for the formulation of wood-based composite
products, wood products for in-ground contact, plastics, exterior
paints, glues and adhesives. Currently, the only residential end-use
products on the market are for exterior treated wood use. Exposure via
incidental ingestion (by children) and inhalation are not a concern for
these products which are used outdoors. No paints or other end-use
products containing tebuconazole are available for interior use.
Accordingly, residential exposure is not expected at this time.
4. Cumulative exposure to substances with common mechanism of
toxicity. Section 408(b)(2)(D)(v) requires that, when considering
whether to establish, modify, or revoke a tolerance, the Agency
consider ``available information'' concerning the cumulative effects of
a particular pesticide's residues and ``other substances that have a
common mechanism of toxicity.''
EPA does not have, at this time, available data to determine
whether tebuconazole has a common mechanism of toxicity with other
substances or how to include this pesticide in a cumulative risk
assessment. Unlike other pesticides for which EPA has followed a
cumulative risk approach based on a common mechanism of toxicity,
tebuconazole does not appear to produce a toxic metabolite produced by
other substances. For the purposes of this tolerance action, therefore,
EPA has not assumed that tebuconazole has a common mechanism of
toxicity with other substances. For more information regarding EPA's
efforts to determine which chemicals have a common mechanism of
toxicity and to evaluate the cumulative effects of such chemicals, see
the Final Rule for Bifenthrin Pesticide Tolerances (62 FR 62961,
November 26, 1997).
C. Aggregate Risks and Determination of Safety for U.S. Population
1. Acute risk. A toxicological endpoint was identified for acute
dietary risk assessments for subpopulations females (13+ years old),
infants and children. The 10X safety factor for enhanced susceptibility
of infants and children as required by FQPA is applicable for all of
these subgroups. Therefore, 10% or less of the acute RfD of 0.1 mg/kg/
day results in an acceptable acute dietary exposure (food plus water).
An acute dietary (food only) probablistic risk analysis resulted in
3% of the acute RfD utilized for females (13+ years old). The maximum
estimated concentrations of tebuconazole in surface and ground water
are less than EPA's levels of concern for acute exposure in drinking
water for the females 13+. Currently the only residential end-use
products on the market are for exterior treated wood use. Exposure via
incidental ingestion (by children) and inhalation are not a concern for
these products which are used outdoors. No paints or other end-use
products containing tebuconazole are available for interior use.
Accordingly residential exposure is not expected with these uses.
Therefore, EPA concludes with reasonable certainty that residues of
tebuconazole do not contribute significantly to the aggregate acute
risk at the present time.
2. Chronic risk. Using the TMRC exposure assumptions described
above, EPA has concluded that aggregate exposure to tebuconazole from
food will utilize 11% of the RfD for the U.S. population. The major
identifiable
[[Page 66453]]
subgroup with the highest aggregate exposure from food is Non-Nursing
Infants (< 1 year old), discussed below. EPA generally has no concern
for exposures below 100% of the RfD because the RfD represents the
level at or below which daily aggregate dietary exposure over a
lifetime will not pose appreciable risks to human health. As stated
above, residential exposure to tebuconazole is not expected for the
currently registered uses. Despite the potential for exposure to
tebuconazole in drinking water, EPA does not expect the aggregate
exposure to exceed 100% of the RfD. Therefore, EPA concludes with
reasonable certainty that residues of tebuconazole do not contribute
significantly to the aggregate chronic risk at the present time.
3. Short- and intermediate-term risk. Short- and intermediate-term
aggregate exposure takes into account chronic dietary food and water
(considered to be a background exposure level) plus indoor and outdoor
residential exposure. No short- or intermediate-term dermal
toxicological endpoints were identified. Also, no residential exposure
is expected from the current residential uses. Thus, no risk
assessments were conducted for residential exposure. Therefore, EPA
concludes with reasonable certainty that tebuconazole does not
contribute significantly to the aggregate short- and intermediate-term
risk at the present time.
4. Aggregate cancer risk for U.S. population. Tebuconazole is
classified as a Group C (possible human) carcinogen. Since, for the
purpose of carcinogenic risk assessment the RfD methodology was used,
the discussion for Chronic risk (11% of RfD utilized) in Unit III.D.2
above applies to cancer risk as well. Therefore, EPA concludes with
reasonable certainty that tebuconazole does not contribute
significantly to the aggregate cancer risk at the present time.
5. Determination of safety. Based on these risk assessments, EPA
concludes that there is a reasonable certainty that no harm will result
from aggregate exposure to tebuconazole residues.
D. Aggregate Risks and Determination of Safety for Infants and Children
1. Safety factor for infants and children-- i. In general. In
assessing the potential for additional sensitivity of infants and
children to residues of tebuconazole, EPA considered data from
developmental toxicity studies in the rat and rabbit and a 2-generation
reproduction study in the rat. The developmental toxicity studies are
designed to evaluate adverse effects on the developing organism
resulting from maternal pesticide exposure during gestation.
Reproduction studies provide information relating to effects from
exposure to the pesticide on the reproductive capability of mating
animals and data on systemic toxicity.
FFDCA section 408 provides that EPA shall apply an additional
tenfold margin of safety for infants and children in the case of
threshold effects to account for pre-and post-natal toxicity and the
completeness of the database unless EPA determines that a different
margin of safety will be safe for infants and children. Margins of
safety are incorporated into EPA risk assessments either directly
through use of a margin of exposure (MOE) analysis or through using
uncertainty (safety) factors in calculating a dose level that poses no
appreciable risk to humans. EPA believes that reliable data support
using the standard MOE and uncertainty factor (usually 100 for combined
inter- and intra-species variability)) and not the additional tenfold
MOE/uncertainty factor when EPA has a complete data base under existing
guidelines and when the severity of the effect in infants or children
or the potency or unusual toxic properties of a compound do not raise
concerns regarding the adequacy of the standard MOE/safety factor.
ii. Developmental toxicity studies. In two associated oral
developmental toxicity studies in mice, the maternal NOAEL was 10 mg/
kg/day and the LOAEL was 20 mg/kg/day, based on decreased hematocrit
and effects in the liver. The developmental toxicity NOAEL was 10 mg/
kg/day and the LOAEL was 30 mg/kg/day, based on increased numbers of
runts (fetuses weighing less than 1.3 grams). In addition, at 100 mg/
kg/day, frank malformations in the skull, brain and spinal column and a
reduced rate of ossification in the cranium were observed. In a dermal
developmental toxicity study in mice, no toxicologically significant
maternal toxicity or developmental toxicity was observed at the limit
dose of 1,000 mg/kg/day.
In an oral developmental toxicity study in rats, the maternal
NOAEL was 30 mg/kg/day and the LOAEL was 60 mg/kg/day, based on
increased liver weight. The developmental toxicity NOAEL was 30 mg/kg/
day and the LOAEL was 60 mg/kg/day, based on delayed ossification of
several bones and increased numbers of fetuses with supernumerary ribs.
In addition, at 120 mg/kg/day, increased resorptions, decreased fetal
body weights and frank malformations in two fetuses (missing tail,
agnatha, microtomia and anophthalmia) were observed. In a dermal
developmental toxicity study in rats, no toxicologically significant
maternal toxicity or developmental toxicity was observed at the limit
dose of 1,000 mg/kg/day.
In an oral developmental toxicity study in rabbits, the maternal
NOAEL was 30 mg/kg/day and the LOAEL was 100 mg/kg/day, based on
decreased body weight gain and decreased food consumption during the
dosing period. The de velopmental toxicity NOAEL was 30 mg/kg/day and
the LOAEL was 100 mg/kg/day, based on increased postimplantation loss,
increased frank malformations, hydrocephalus and delayed ossification
of bones. In another oral developmental toxicity study in rabbits, the
maternal NOAEL was < 10 mg/kg/day and the LOAEL was 10 mg/kg/day, based
on increased incidences of single cell necrosis (minimal severity) in
liver cells. The maternal NOAEL from this study was not used to
determine the acute RfD because single cell necrosis was not considered
to result from a single exposure. The developmental toxicity NOAEL was
30 mg/kg/day and the LOAEL was 100 mg/kg/day, based on increased
postimplantation loss, decreased fetal body weights, increased
percentage of fetuses with abnormalities (including runts,
hemidiaphragm, limb abnormalities and neural tube defects characterized
as meningocoele and spina bifida) and delayed ossification of bones.
iii. Reproductive toxicity study. In a 2-generation reproduction
study in rats, the parental (systemic) toxicity NOAEL was 15 mg/kg/day
and the LOAEL was 50 mg/kg/day, based on loss of hair, decreased body
weights, decreased food consumption, increased severity of spleen
hemosiderosis and decreased liver and kidney weights. For offspring
toxicity, the NOAEL was 15 mg/kg/day and the LOAEL was 50 mg/kg/day,
based on decreased pup body weights from birth through weeks 3-4 in all
litter groups.
iv. Pre- and post-natal sensitivity. The above studies meet the
standard toxicology data requirements, as required for a food-use
chemical, in 40 CFR part 158. However, after evaluation of the findings
in these studies, particularly with respect to effects on the fetal
nervous system, together with a consideration of neurotoxic effects
observed in several other developmental toxicity studies on
structurally related triazole pesticides, the Agency requested a
postnatal developmental neurotoxicity study in rats (Guideline 83-6) be
conducted. The EPA notes effects on the nervous system of fetuses in
studies on tebuconazole occurred only at doses of 100 mg/kg/day or
[[Page 66454]]
higher--i.e. at doses at least tenfold higher than the developmental
toxicity NOAEL (10 mg/kg/day) to be used for the assessment of acute
dietary risk.
On the basis of comparative NOAELs and LOAELs, it was determined
there was no indication of increased susceptibility of the offspring of
mice, rats or rabbits resulting from prenatal and/or postnatal exposure
to tebuconazole. However, the maternal effects observed in the
developmental toxicity studies at the LOAEL were of minimal concern and
did not increase substantially in severity at higher doses, whereas the
developmental effects at the LOAEL were pronounced and at higher doses
were quite severe (including frank malformations) in mice (at 100 mg/
kg/day), rats (at 120 mg/kg/day) and rabbits (at 100 mg/kg/day). Based
on a consideration of all the above findings, the Agency retained the
10X factor for enhanced susceptibility to infants and children. The 10X
factor is applicable to acute dietary exposures for the subpopulations
females (13+ years old), infants and children. The 10x factor for
enhanced sensitivity of infants and children is not applicable to
chronic exposure analysis.
v. Conclusion. There is a complete toxicity data base for
tebuconazole and exposure data is complete or is estimated based on
data that reasonably accounts for potential exposures.
2. Acute risk. An acute dietary (food only) probablistic risk
analysis resulted in the following percentages for the acute RfD:
nursing infants (< 1 year old), 7%; non-nursing infants (< 1 year old),
7%; children (1 to 6 years old) 9%, children (7 to 12 years old) 3%;
and all infants (< 1 year old), 7%. The maximum estimated
concentrations of tebuconazole in surface and ground water are less
than EPA's levels of concern for acute exposure in drinking water for
children. Currently the only residential end-use products on the market
are for exterior treated wood use. Exposure via incidental ingestion
(by children) and inhalation are not a concern for these products which
are used outdoors. No paints or other end-use products containing
tebuconazole are available for interior use. Accordingly residential
exposure is not expected with these uses. Therefore, EPA concludes with
reasonable certainty that residues of tebuconazole do not contribute
significantly to the aggregate acute risk at the present.
3. Chronic risk. Using the exposure assumptions described above,
EPA has concluded that aggregate exposure to tebuconazole from food
will utilize up to 37% of the RfD for infants and children. EPA
generally has no concern for exposures below 100% of the RfD because
the RfD represents the level at or below which daily aggregate dietary
exposure over a lifetime will not pose appreciable risks to human
health. As stated above, residential exposure to tebuconazole is not
expected for the currently registered uses. Despite the potential for
exposure to tebuconazole in drinking water, EPA does not expect the
aggregate exposure to exceed 100% of the RfD. Therefore, EPA concludes
with reasonable certainty that residues of tebuconazole do not
contribute significantly to the aggregate chronic risk at the present
time.
4. Short- or intermediate-term risk. As stated above, residential
exposure to tebuconazole is not expected for the currently registered
uses.
5. Determination of safety. Based on these risk assessments, EPA
concludes that there is a reasonable certainty that no harm will result
to infants and children from aggregate exposure to tebuconazole
residues.
IV. Other Considerations
A. Metabolism In Plants
The metabolism of tebuconazole in or on grapes, wheat, and peanuts
have been reviewed. The nature of the residue in wheat is adequately
understood. For the purposes of this section 18, the nature of the
residue in hops is considered to be adequately understood (by
translation from grapes, wheat and peanuts). The residue of concern in
plants is tebuconazole per se.
B. Analytical Enforcement Methodology
Adequate enforcement methodology is available to enforce the
tolerance expression. The method entitled ``Gas Chromatographic Method
[GLC/TSD] for Determination of Residues of Tebuconazole in Crops,
Processed Products, Soil and Water'' ( PP #9F3724) is adequate to
enforce time-limited tolerances for residues of tebuconazole in or on
hops. The method may be requested from: Calvin Furlow, PRRIB, IRSD
(7502C), Office of Pesticide Programs, Environmental Protection Agency,
401 M St., SW., Washington, DC 20460. Office location and telephone
number: Rm 101FF, Crystal Mall #2, 1921 Jefferson Davis Hwy.,
Arlington, VA 22202, (703-305-5229).
C. Magnitude of Residues
Residues of tebuconazole per se are not expected to exceed 4.0 ppm
in or on dried hops cones as a result of this section 18 use.
D. International Residue Limits
There are no Codex, Canadian, or Mexican maximum residue limits
for residues of tebuconazole in or on dried hops cones. International
harmonization is thus not an issue for this time-limited tolerance.
E. Rotational Crop Restrictions
A plantback interval of 120 days after last application for crops
not listed on the label is required. However, rotation restrictions are
not applicable to hops as these crops are not normally rotated.
V. Conclusion
Therefore, the tolerance is established for residues of
tebuconazole in hops at 4.0 ppm.
VI. Objections and Hearing Requests
The new FFDCA section 408(g) provides essentially the same process
for persons to ``object'' to a tolerance regulation issued by EPA under
new section 408(e) and (l)(6) as was provided in the old section 408
and in section 409. However, the period for filing objections is 60
days, rather than 30 days. EPA currently has procedural regulations
which govern the submission of objections and hearing requests. These
regulations will require some modification to reflect the new law.
However, until those modifications can be made, EPA will continue to
use those procedural regulations with appropriate adjustments to
reflect the new law.
Any person may, by February 1, 1999, file written objections to any
aspect of this regulation and may also request a hearing on those
objections. Objections and hearing requests must be filed with the
Hearing Clerk, at the address given above (40 CFR 178.20). A copy of
the objections and/or hearing requests filed with the Hearing Clerk
should be submitted to the OPP docket for this rulemaking. The
objections submitted must specify the provisions of the regulation
deemed objectionable and the grounds for the objections (40 CFR
178.25). Each objection must be accompanied by the fee prescribed by 40
CFR 180.33(i). If a hearing is requested, the objections must include a
statement of the factual issues on which a hearing is requested, the
requestor's contentions on such issues, and a summary of any evidence
relied upon by the requestor (40 CFR 178.27). A request for a hearing
will be granted if the Administrator determines that the material
submitted shows the following: There is genuine and substantial issue
of fact; there is a reasonable possibility that available evidence
identified by the requestor would, if established, resolve one or more
of such issues in favor of the requestor, taking into account
uncontested claims or facts to the
[[Page 66455]]
contrary; and resolution of the factual issues in the manner sought by
the requestor would be adequate to justify the action requested (40 CFR
178.32). Information submitted in connection with an objection or
hearing request may be claimed confidential by marking any part or all
of that information as CBI. Information so marked will not be disclosed
except in accordance with procedures set forth in 40 CFR part 2. A copy
of the information that does not contain CBI must be submitted for
inclusion in the public record. Information not marked confidential may
be disclosed publicly by EPA without prior notice.
VII. Public Record and Electronic Submissions
EPA has established a record for this rulemaking under docket
control number [OPP-300745] (including any comments and data submitted
electronically). A public version of this record, including printed,
paper versions of electronic comments, which does not include any
information claimed as CBI, is available for inspection from 8:30 a.m.
to 4 p.m., Monday through Friday, excluding legal holidays. The public
record is located in Room 119 of the Public Information and Records
Integrity Branch, Information Resources and Services Division (7502C)
Office of Pesticide Programs, Environmental Protection Agency, Crystal
Mall #2, 1921 Jefferson Davis Highway, Arlington, VA.
Electronic comments may be sent directly to EPA at:
opp-docket@epamail.epa.gov.
Electronic comments must be submitted as an ASCII file avoiding the
use of special characters and any form of encryption.
The official record for this rulemaking, as well as the public
version, as described above will be kept in paper form. Accordingly,
EPA will transfer any copies of objections and hearing requests
received electronically into printed, paper form as they are received
and will place the paper copies in the official rulemaking record which
will also include all comments submitted directly in writing. The
official rulemaking record is the paper record maintained at the
Virginia address in ``ADDRESSES'' at the beginning of this document.
VIII. Regulatory Assessment Requirements
A. Certain Acts and Executive Orders
This final rule establishes a tolerance under FFDCA section 408
(l)(6). The Office of Management and Budget (OMB) has exempted these
types of actions from review under Executive Order 12866, entitled
Regulatory Planning and Review (58 FR 51735, October 4, 1993). This
final rule does not contain any information collections subject to OMB
approval under the Paperwork Reduction Act (PRA), 44 U.S.C. 3501 et
seq., or impose any enforceable duty or contain any unfunded mandate as
described under Title II of the Unfunded Mandates Reform Act of 1995
(UMRA) (Pub. L. 104-4). Nor does it require any special considerations
as required by Executive Order 12898, entitled Federal Actions to
Address Environmental Justice in Minority Populations and Low-Income
Populations (59 FR 7629, February 16, 1994), or require OMB review in
accordance with Executive Order 13045, entitled Protection of Children
from Environmental Health Risks and Safety Risks (62 FR 19885, April
23, 1997).
In addition, since tolerances and exemptions that are established
under FFDCA section 408 (l)(6), such as the tolerance in this final
rule, do not require the issuance of a proposed rule, the requirements
of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et seq.) do not
apply. Nevertheless, the Agency has previously assessed whether
establishing tolerances, exemptions from tolerances, raising tolerance
levels or expanding exemptions might adversely impact small entities
and concluded, as a generic matter, that there is no adverse economic
impact. The factual basis for the Agency's generic certification for
tolerance acations published on May 4, 1981 (46 FR 24950), and was
provided to the Chief Counsel for Advocacy of the Small Business
Administration.
B. Executive Order 12875
Under Executive Order 12875, entitled Enhancing the
Intergovernmental Partnership (58 FR 58093, October 28, 1993), EPA may
not issue a regulation that is not required by statute and that creates
a mandate upon a State, local, or tribal government, unless the Federal
government provides the funds necessary to pay the direct compliance
costs incurred by those governments. If the mandate is unfunded, EPA
must provide to OMB a description of the extent of EPA's prior
consultation with representatives of affected State, local, and tribal
governments, the nature of their concerns, copies of any written
communications from the governments, and a statement supporting the
need to issue the regulation. In addition, Executive Order 12875
requires EPA to develop an effective process permitting elected
officials and other representatives of State, local, and tribal
governments ``to provide meaningful and timely input in the development
of regulatory proposals containing significant unfunded mandates.''
Today's rule does not create an unfunded Federal mandate on State,
local, or tribal governments. The rule does not impose any enforceable
duties on these entities. Accordingly, the requirements of section 1(a)
of Executive Order 12875 do not apply to this rule.
C. Executive Order 13084
Under Executive Order 13084, entitled Consultation and Coordination
with Indian Tribal Governments (63 FR 27655, May 19,1998), EPA may not
issue a regulation that is not required by statute, that significantly
or uniquely affects the communities of Indian tribal governments, and
that imposes substantial direct compliance costs on those communities,
unless the Federal government provides the funds necessary to pay the
direct compliance costs incurred by the tribal governments. If the
mandate is unfunded, EPA must provide to OMB, in a separately
identified section of the preamble to the rule, a description of the
extent of EPA's prior consultation with representatives of affected
tribal governments, a summary of the nature of their concerns, and a
statement supporting the need to issue the regulation. In addition,
Executive Order 13084 requires EPA to develop an effective process
permitting elected officials and other representatives of Indian tribal
governments ``to provide meaningful and timely input in the development
of regulatory policies on matters that significantly or uniquely affect
their communities.''
Today's rule does not significantly or uniquely affect the
communities of Indian tribal governments. This action does not involve
or impose any requirements that affect Indian tribes. Accordingly, the
requirements of section 3(b) of Executive Order 13084 do not apply to
this rule.
IX. Submission to Congress and the Comptroller General
The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. EPA will submit a
[[Page 66456]]
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 the rule in the Federal
Register. This rule is not a ``major rule'' as defined by 5 U.S.C.
804(2).
List of Subjects in 40 CFR Part 180
Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and
recordkeeping requirements.
Dated: October 6, 1998.
Arnold E. Layne,
Acting Director, Registration Division, Office of Pesticide Programs.
Therefore, 40 CFR chapter I is amended as follows:
PART 180--[AMENDED]
1. The authority citation for part 180 continues to read as
follows:
Authority: 21 U.S.C. 346a and 371.
2. In Sec. 180.474, in the table to paragraph (b)(1) by adding an
entry for ``Hops'' to read as follows:
Sec. 180.474 Tebuconazole; tolerances for residues.
* * * * *
(b) * * *
------------------------------------------------------------------------
Parts Expiration/
Commodity per Revocation
million Date
------------------------------------------------------------------------
Hops.............................................. 4.0 12/31/00
------------------------------------------------------------------------
* * * * *
[FR Doc. 98-31684 Filed 12-1-98; 8:45 am]
BILLING CODE 6560-50-F