[Federal Register: September 22, 2004 (Volume 69, Number 183)]
[Rules and Regulations]
[Page 56711-56718]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr22se04-15]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-2004-0278; FRL-7679-5]
Tribenuron Methyl; Pesticide Tolerance
AGENCY: Environmental Protection Agency EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes a tolerance for residues of
tribenuron methyl in or on canola, seed; cotton, gin byproducts;
cotton, undelinted seed; and flax, seed. E.I. DuPont De Nemours and
Company requested this tolerance under the Federal Food, Drug, and
Cosmetic Act (FFDCA), as amended by the Food Quality Protection Act of
1996 (FQPA). In addition, this regulatory action is part of the
tolerance reassessment requirements of section 408(q) of the FFDCA 21
U.S.C. 346a(q), as amended by the FQPA of 1996. By law, EPA is required
to reassess 100% of the tolerances in existence on August 2, 1996, by
August 2006. This regulatory action will count for eight reassessments
toward the August 2006 deadline.
DATES: This regulation is effective September 22, 2004. Objections and
requests for hearings must be received on or before November 22, 2004.
ADDRESSES: To submit a written objection or hearing request follow the
detailed instructions as provided in Unit VI. of the SUPPLEMENTARY
INFORMATION. EPA has established a docket for this action under Docket
identification (ID) number OPP-2004-0278. All documents in the docket
are listed in the EDOCKET index at http://www.epa.gov/edocket. Although
listed in the index, some information is not publicly available, i.e.,
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 either electronically
in EDOCKET or in hard copy at the Public Information and Records
Integrity Branch (PIRIB), Rm. 119, Crystal Mall 2, 1801 S.
Bell St., Arlington, VA. This docket facility is open from 8:30 a.m. to
4 p.m., Monday through Friday, excluding legal holidays. The docket
telephone number is (703) 305-5805.
FOR FURTHER INFORMATION CONTACT: James Tompkins, Registration Division
(7505C), Office of Pesticide Programs, Environmental Protection Agency,
1200 Pennsylvania Ave., NW.,Washington, DC 20460-0001; telephone
number: 703-305-5697 e-mail address: tompkins.jim@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:
Crop production (NAICS 111), e.g., agricultural workers;
greenhouse, nursery, and floriculture workers; farmers.
Animal production (NAICS 112), e.g., cattle ranchers and
farmers, dairy cattle farmers, livestock farmers.
Food manufacturing (NAICS 311), e.g., agricultural
workers; farmers; greenhouse, nursery, and floriculture workers;
ranchers; pesticide applicators.
Pesticide manufacturing (NAICS 32532), e.g., agricultural
workers; commercial applicators; farmers; greenhouse, nursery, and
floriculture workers; residential users.
This listing is not intended to be exhaustive, but rather provides
a guide for readers regarding entities likely to be affected by this
action. Other types of entities not listed in 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 Access Electronic Copies of This Document and Other
Related Information?
In addition to using EDOCKET (http://www.epa.gov/edocket/), you may
access this Federal Register document electronically through the EPA
Internet under the ``Federal Register'' listings at http://www.epa.gov/fedrgstr/.
A frequently updated electronic version of 40 CFR part 180
is available at E-CFR Beta Site Two at http://www.gpoaccess.gov/ecfr/.
To access the OPPTS Harmonized Guidelines referenced in this document,
go directly to the guidelines at http://www.epa.gpo/opptsfrs/home/guidelin.htm/
.
II. Background and Statutory Findings
In the Federal Register of July 7, 2004 (69 FR 40909) (FRL-7364-8),
EPA issued a notice pursuant to section 408(d)(3) of FFDCA, 21 U.S.C.
346a(d)(3), announcing the filing of a pesticide petition (PP 0F6135)
by E.I. DuPont de Nemours and Company, DuPont Crop Protection, Barley
Mill Plaza, Wilmington, DE 19880-0038. The petition requested that 40
CFR 180.451 be amended by establishing a tolerance for residues of the
herbicide tribenuron methyl, [methyl 2-[[[[(4-methoxy -6-methyl-1, 3,
5-triazin-2-yl) methylamino] carbobyl]amino]sulfonyl]benzoate], in or
on imazethapyr tolerant canola at 0.02 parts per million (ppm), cotton
gin trash at 0.02 ppm, cotton seed at 0.02 ppm, and Crop Development
Center (CDC) triffid flax at 0.02 ppm. That notice included a summary
of the petition prepared by E. I. DuPont de Nemours and Company, the
registrant. There were no comments received in response to the notice
of filing.
During the course of the review the Agency decided to correct the
Company address and correct the listings for the commodities canola,
cotton and flax. The company address is changed to DuPont Crop
Protection, Stine-Haskell Research Center, Newark, DE 19714. The
listing of the commodities imazethapyr tolerant canola, cotton seed,
cotton gin trash and Crop Development Center (CDC) triffid flax are
corrected to read canola, seed; cotton, undelinted seed; cotton, gin
byproducts and flax, seed; respectively.
Section 408(b)(2)(A)(i) of FFDCA allows EPA to establish a
tolerance (the legal limit for a pesticide chemical residue in or on a
food) only if EPA determines that the tolerance is ``safe.'' Section
408(b)(2)(A)(ii) of FFDCA defines ``safe'' to mean that ``there is a
reasonable certainty that no harm will result from aggregate exposure
to the pesticide chemical residue, including all anticipated dietary
exposures and all other exposures for which there is reliable
information.'' This includes exposure through drinking water and in
residential settings, but does not include occupational exposure.
Section 408(b)(2)(C) of FFDCA requires EPA to give special
consideration to exposure of infants and children to the pesticide
chemical residue in establishing a tolerance and to ``ensure that there
is a reasonable certainty that no harm will result to infants and
children from aggregate exposure to the pesticide chemical residue. * *
*''
EPA performs a number of analyses to determine the risks from
aggregate
[[Page 56712]]
exposure to pesticide residues. For further discussion of the
regulatory requirements of section 408 of FFDCA and a complete
description of the risk assessment process, see the final rule on
Bifenthrin Pesticide Tolerances (62 FR 62961, November 26, 1997) (FRL-
5754-7).
III. Aggregate Risk Assessment and Determination of Safety
Consistent with section 408(b)(2)(D) 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, consistent with section
408(b)(2) of FFDCA, for a tolerance for residues of tribenuron methyl
on canola, seed at 0.02 ppm, cotton, gin byproducts at 0.02 ppm,
cotton, undelinted seed at 0.02 ppm, and flax, seed at 0.02 ppm. EPA's
assessment of 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 tribenuron methyl
are discussed in Table 1 of this unit as well as the no-observed-
adverse-effect-level (NOAEL) and the lowest-observed-adverse-effect-
level (LOAEL) from the toxicity studies reviewed.
Table 1.--Subchronic, Chronic, and Other Toxicity
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Guideline No. Study Type Results
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870.3100 90-Day oral toxicity-- NOAEL = 7 (males and 8 (females) milligrams/
rodents kilogram/day (mg/kg/day)
LOAEL = 118 (males) and 135 (females) mg/kg/
day based on decreased body weight gain,
food consumption and food efficiency;
decreased absolute heart, liver, and
kidney weights; increase relative brain,
heart, liver, kidney, testes, and spleen
weights; decreased serum glucose and
globulin; no histopathologic lesions;
likely cachexia
----------------------------------------
870.3150 90-Day oral toxicity-- NOAEL = > 73.3 (males) and > 78.0 (females)
nonrodents HDT mg/kg/day
----------------------------------------
870.3200 21/28-Day dermal toxicity NOAEL = limit dose, 1,000 mg/kg/day,
resulted in serious toxicity and death. No
NOAEL or LOEAL defined. Toxicity included
treatment site lesions, hypokinesia,
decreased body weights and food
consumption, and kidney pathology, but the
cause of death could not be determined.
Although this study is core supplementary,
another study is not needed. Worker
exposure is expected to be 4 to 5 orders
of magnitude less than limit dose.
----------------------------------------
870.3700 Prenatal developmental-- Maternal NOAEL = 20 mg/kg/day
rodents Maternal LOAEL = 125 mg/kg/day based on
decreased maternal body weight gain and
food consumption
Developmental NOAEL = 20 mg/kg/day
Developmental LOAEL = 125 mg/kg/day based
on decreased body weight. At 500 mg/kg/day
(HDT) there were increased resorption,
fetal deaths, and incomplete ossifications
----------------------------------------
870.3700 Prenatal developmental-- Maternal NOAEL = 20 mg/kg/day
nonrodents Maternal LOAEL = 80 (HDT) mg/kg/day based
on 10% decreased food consumption,
increased abortions
Developmental NOAEL = 20 mg/kg/day
Developmental LOAEL = 80 mg/kg/day based on
HDT-10% decrease in body weight compared
to controls-not statistically
significant). Abortions were increased at
80 mg/kg/day. Teratology was not observed.
----------------------------------------
870.3800 Reproduction and fertility Parental/Systemic NOAEL = 2 mg/kg/day
effects Parental/Systemic LOAEL = 21 mg/kg/day
based on decreased body weight gain in F1a
adult females
Reproductive NOAEL = 2.5 mg/kg/day
Reproductive LOAEL = 25 mg/kg/day based on
decreased body weight gain during
lactation for F1b and F2b pups
Offspring NOAEL = 2.5 mg/kg/day
Offspring LOAEL = 25 mg/kg/day based on
decreased absolute splenic weights
----------------------------------------
870.4100 Chronic toxicity--rodents NOAEL = 0.95 (males)/1.2 (females) mg/kg/
day
LOAEL = 10 (males)/13 (females) mg/kg/day
based on decreased body weight gain in
both sexes.
Statistically significant increase in
mammary gland adenocarcinomas in female
rats at 76 mg/kg/day highest dose tested
(HDT)
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870.4100 Chronic toxicity--dogs NOAEL = 0.79 (males)/8.16 (females) mg/kg/
day
LOAEL = 8.18 (males)/52.02 (females) mg/kg/
day based on elevated serum bilirubin,
AST, and urinary volume, reduced body
weight gain (20%) in females; increased
serum creatinine, bilirubin, AST, and
globulin, decreased body weight gain of
18.2% in males.
----------------------------------------
[[Page 56713]]
870.4200 Carcinogenicity--rats NOAEL = 0.95 (males)/1.2 (females) mg/kg/
day
LOAEL = 10 (males)/13 (females) mg/kg/day
based on decreased body weight gain in
both sexes.
Statistically significant increase in
mammary gland adenocarcinomas in female
rats at 76 mg/kg/day (HDT)
----------------------------------------
870.4300 Supplement-Estrogenic Dose levels: 0 and 390 mg/kg/day for 90
Activity in Rats days.
Weak estrogenic activity was observed in
female rats. The technical and seven
metabolites may be agonists for the
estrogen receptor.
----------------------------------------
870.4300 Carcinogenicity--mice NOAEL = 3 (males) mg/kg/day
LOAEL = 30 mg/kg/day based on bilateral
seminiferous degenertion and oligospermia.
Although frank toxicity was not observed
in the females, HED peer review judged the
dose levels to be adequate.
No evidence of carcinogenicity
----------------------------------------
870.5100 Gene mutation Bacterial negative in Salmonella Typhimurium
----------------------------------------
870.5300 Gene Mutation Mammalian negative in Chinese hamster ovary cells in
in vitro
----------------------------------------
870.5375 Cytogenetics negative for structural chromosomal damage
and when tested in a micronucleus test in
mice
----------------------------------------
870.7485 Metabolism and The major route of excretion in rats is the
pharmacokinetics urine. Urine samples contained two to four
times of the administered radioactivity
than the feces. Tissue levels of
tribenuron methyl and its metabolites
increased with dose, but there was no
concentration of radioactivity in any
particular organ or tissue.
----------------------------------------------------------------------------------------------------------------
B. Toxicological Endpoints
The dose at which no adverse effects are observed (the NOAEL) from
the toxicology study identified as appropriate for use in risk
assessment is used to estimate the toxicological level of concern
(LOC). However, the lowest dose at which adverse effects of concern are
identified (the LOAEL) is sometimes used for risk assessment if no
NOAEL was achieved in the toxicology study selected. An uncertainty
factor (UF) is applied to reflect uncertainties inherent in the
extrapolation from laboratory animal data to humans and in the
variations in sensitivity among members of the human population as well
as other unknowns. An UF of 100 is routinely used, 10X to account for
interspecies differences and 10X for intraspecies differences.
Three other types of safety or uncertainty factors may be used:
``Traditional uncertainty factors;'' the ``special FQPA safety
factor;'' and the ``default FQPA safety factor.'' By the term
``traditional uncertainty factor,'' EPA is referring to those
additional uncertainty factors used prior to FQPA passage to account
for database deficiencies. These traditional uncertainty factors have
been incorporated by the FQPA into the additional safety factor for the
protection of infants and children. The term ``special FQPA safety
factor'' refers to those safety factors that are deemed necessary for
the protection of infants and children primarily as a result of the
FQPA. The ``default FQPA safety factor'' is the additional 10X safety
factor that is mandated by the statute unless it is decided that there
are reliable data to choose a different additional factor (potentially
a traditional uncertainty factor or a special FQPA safety factor).
For dietary risk assessment (other than cancer) the Agency uses the
UF to calculate an acute or chronic reference dose (aRfD or cRfD) where
the RfD is equal to the NOAEL divided by an UF of 100 to account for
interspecies and intraspecies differences and any traditional
uncertainty factors deemed appropriate (RfD = NOAEL/UF). Where a
special FQPA safety factor or the default FQPA safety factor is used,
this additional factor is applied to the RfD by dividing the RfD by
such additional factor. The acute or chronic Population Adjusted Dose
(aPAD or cPAD) is a modification of the RfD to accommodate this type of
safety factor.
For non-dietary risk assessments (other than cancer) the UF is used
to determine the LOC. For example, when 100 is the appropriate UF (10X
to account for interspecies differences and 10X for intraspecies
differences) the LOC is 100. To estimate risk, a ratio of the NOAEL to
exposures (margin of exposure (MOE) = NOAEL/exposure) is calculated and
compared to the LOC.
The linear default risk methodology (Q*) is the primary method
currently used by the Agency to quantify carcinogenic risk. The Q*
approach assumes that any amount of exposure will lead to some degree
of cancer risk. A Q* is calculated and used to estimate risk which
represents a probability of occurrence of additional cancer cases
(e.g., risk). An example of how such a probability risk is expressed
would be to describe the risk as one in one hundred thousand (1 X
10-\5\), one in a million (1 X 10-\6\), or 1 in
10 million (1 X 10-\7\). Under certain specific
circumstances, MOE calculations will be used for the carcinogenic risk
assessment. In this non-linear approach, a ``point of departure'' is
identified below which carcinogenic effects are not expected. The point
of departure is typically a NOAEL based on an endpoint related to
cancer effects though it may be a different value derived from the dose
response curve. To estimate risk, a ratio of the point of departure to
exposure (MOEcancer = point of departure/exposures) is
calculated.
A summary of the toxicological endpoints for tribenuron methyl used
for human risk assessment is shown in the following Table 2:
[[Page 56714]]
Table 2.--Summary of Toxicological Dose and Endpoints for Tribenuron methyl for Use in Human Risk Assessment
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Dose Used in Risk
Assessment, Special FQPA SF and
Exposure Scenario Interspecies and Level of Concern for Study and Toxicological
Intraspecies and any Risk Assessment Effects
Traditional UF
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Chronic Dietary (All populations) NOAEL= 0.8 mg/kg/day Special FQPA SF = 1 Chronic Dog LOAEL = 8.2
UF = 100............... cPAD = chronic RfD / mg/kg/day based on
Chronic RfD = 0.008 mg/ Special FQPA SF = elevated bilirubin,
kg/day. 0.008 mg/kg/day. elevated serum liver
enzymes, increased
urinary volume, and
20% reduction in body
weight gain.
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Cancer (oral, dermal, inhalation) Classified as Group C chronic risk assessment NA
(possible human protective of any
carcinogen) not potential carcinogenic
mutagenic) risk
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C. Exposure Assessment
1. Dietary exposure from food and feed uses. Tolerances have been
established (40 CFR 180.451) for the residues of tribenuron methyl, in
or on a variety of raw agricultural commodities. Tolerances are
established for barley, oats, wheat, and grass forage and hay group. No
tolerances for meat products, eggs, or milk are established. Risk
assessments were conducted by EPA to assess dietary exposures from
tribenuron methyl in food as follows:
i. Acute exposure. Acute dietary risk assessments are performed for
a food-use pesticide, if a toxicological study has indicated the
possibility of an effect of concern occurring as a result of a 1-day or
single exposure.
There are no studies that identify an acute hazard based on toxic
effects observed following a single oral exposure (dose) of tribenuron
methyl. The developmental toxicity rat study in which a 9% reduction in
body weight occurred on the fourth day of dosing (day 9) was
considered. However, this reduction in body weight gain was only slight
and could not be attributed to a single dose since the reduction
occurred on day 4 of dosing. Other effects observed in the
developmental toxicity study such as decreased fetal wight (7.4%) and
increased incidence of fetal resorptions (not statistically
significant) were considered for an endpoint in reproductive females,
but again, effects could not be attributed to a single dose. Since
there was no litter loss or other acute effects, the aRfD is not
appropriate for the assessment.
ii. Chronic exposure. Dietary exposure estimates were conducted
using the Lifeline model (Version 2.0) which incorporates consumption
data from the USDA Continuing Surveys of Food Intakes by Individuals
(CSFII), 1994-96 and 1998. The 1994-96, 1998 data are based on reported
consumption of more than 20,000 individuals over two non-consecutive
survey days. Foods ``as consumed'' are linked to EPA-defined food
commodities using publicly available recipe translation files
(developed jointly by USDA/ARS and EPA). Lifeline models individual
dietary exposures over a season by selecting a new CSFII diary each day
from a set of similar individuals, based on age and season attributes.
The Lifeline chronic dietary exposure estimate is based on an average
daily exposure from a profile of 1,000 individuals over a 1-year
period. Further information regarding the Lifetime model can be found
at the following we site:http://www.Lifeline TMgroup.org.
The following assumptions were made for the chronic exposure
assessments: Tolerance level, 100% crop treated (CT), and default
processing factors were used. Percent crop treated (PCT) or anticipated
residues were not used.
iii. Cancer. Tribenuron methyl is classified as a Group C (Possible
Human Carcinogen). The Agency also concluded that the carcinogenic
response observed may be associated with a hormonal imbalance that may
not occur at doses below a maximum tolerated dose ( MTD). A
quantitative carcinogenic risk assessment for tribenuron methyl is not
considered appropriate because: (1) The increased incidence of mammary
gland tumors was observed in female rats treated at the dose levels
exceeding the (MTD; (2) there was no evidence of genetic toxicity shown
in several studies; (3) structural analogs of tribenuron methyl were
not associated with carcinogenic responses in rats and mice. In
conclusion the Agency considers the chronic risk assessment, making use
of the cPAD, to be protective of any potential carcinogenic risk.
2. Dietary exposure from drinking water. The Agency lacks
sufficient monitoring exposure data to complete a comprehensive dietary
exposure analysis and risk assessment for tribenuron methyl in drinking
water. Because the Agency does not have comprehensive monitoring data,
drinking water concentration estimates are made by reliance on
simulation or modeling taking into account data on the physical
characteristics of tribenuron methyl.
The Agency uses the FQPA Index Reservoir Screening Tool (FIRST) or
the Pesticide Root Zone Model/Exposure Analysis Modeling System (PRZM/
EXAMS), to produce estimates of pesticide concentrations in an index
reservoir. The SCI-GROW model is used to predict pesticide
concentrations in shallow ground water. For a screening-level
assessment for surface water EPA will use FIRST (a tier 1 model) before
using PRZM/EXAMS (a tier 2 model). The FIRST model is a subset of the
PRZM/EXAMS model that uses a specific high-end runoff scenario for
pesticides. Both FIRST and PRZM/EXAMS incorporate an index reservoir
environment, and both models include a percent crop area factor as an
adjustment to account for the maximum percent crop coverage within a
watershed or drainage basin.
None of these models include consideration of the impact processing
(mixing, dilution, or treatment) of raw water for distribution as
drinking water would likely have on the removal of pesticides from the
source water. The primary use of these models by the Agency at this
stage is to provide a screen for sorting out pesticides for which it is
unlikely that drinking water concentrations would exceed human health
levels of concern.
Since the models used are considered to be screening tools in the
risk assessment process, the Agency does not use estimated
environmental concentrations (EECs), which are the model estimates of a
pesticide's concentration in water. EECs derived from these models are
used to quantify drinking water exposure and risk as a %RfD or %PAD.
Instead, drinking water levels of comparison (DWLOCs) are
[[Page 56715]]
calculated and used as a point of comparison against the model
estimates of a pesticide's concentration in water. DWLOCs are
theoretical upper limits on a pesticide's concentration in drinking
water in light of total aggregate exposure to a pesticide in food, and
from residential uses. Since DWLOCs address total aggregate exposure to
tribenuron methyl they are further discussed in the aggregate risk Unit
III.E.
Based on the FIRST, and SCI-GROW models, the EECs of tribenuron
methyl for chronic exposures are estimated to be .413 ppb for surface
water and 0.000006 ppb for ground 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).
Tribenuron methyl is not registered for use on any sites that would
result in residential exposure.
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.''
Unlike other pesticides for which EPA has followed a cumulative
risk approach based on a common mechanism of toxicity, EPA has not made
a common mechanism of toxicity finding as to tribenuron methyl and any
other substances and tribenuron methyl 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 tribenuron methyl
has a common mechanism of toxicity with other substances. For
information regarding EPA's efforts to determine which chemicals have a
common mechanism of toxicity and to evaluate the cumulative effects of
such chemicals, see the policy statements released by EPA's Office of
Pesticide Programs (OPP) concerning common mechanism determinations and
procedures for cumulating effects from substances found to have a
common mechanism on EPA's web site at http://www.epa.gov/pesticides/cumulative/
.
D. Safety Factor for Infants and Children
1. In general. Section 408 of FFDCA provides that EPA shall apply
an additional 10-fold 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. Margins of safety are
incorporated into EPA risk assessments either directly through use of a
maragin of exposure (MOE) analysis or through using uncertainty
(safety) factors in calculating a dose level that poses no appreciable
risk to humans. In applying this provision, EPA either retains the
default value of 10X when reliable data do not support the choice of a
different factor, or, if reliable data are available, EPA uses a
different additional safety factor value based on the use of
traditional uncertainty factors and/or special FQPA safety factors, as
appropriate.
2. Prenatal and postnatal sensitivity. Developmental and
reproductive toxicity studies indicated no increased susceptibility of
offspring to tribenuron methyl. However, increased number of
resorptions (not statistically significant) and fetal deaths were
observed at the highest dose tested when administered during the
critical gestation period of pregnancy, in both the rat and the rabbit.
The resorptions and fetal deaths indicate an effect due to maternal
toxicity. In a two-generation reproduction study, reproductive effects
of tribenuron methyl were limited to decreased body weight gain during
lactation.
3. Conclusion. There is a complete toxicity database for tribenuron
methyl and exposure data are complete or are estimated based on data
that reasonably accounts for potential exposures. The impact of
tribenuron methyl on the nervous system has not been specifically
evaluated in neurotoxicity studies. However, there was no evidence of
neurotoxicity or neuropathology seen in either acute, subchronic,
chronic, or reproductive studies, and there are no concerns for
potential developmental neurotoxicity. Therefore, neurotoxicity data
are not required for tribenuron methyl. EPA determined that the 10X SF
to protect infants and children should be removed. The FQPA factor is
removed because of the completeness of the toxicity and exposure
database and because the available data provided no indication of
increased susceptibility (quantitative or qualitative) to rats or
rabbits following in utero exposure to tribenuron methyl, or to
prenatal and/or postnatal exposure in rat reproduction studies and
there are no concerns for potential developmental neurotoxicity.
E. Aggregate Risks and Determination of Safety
To estimate total aggregate exposure to a pesticide from food,
drinking water, and residential uses, the Agency calculates DWLOCs
(drinking water level of concern) which are used as a point of
comparison against EECs. DWLOC values are not regulatory standards for
drinking water. DWLOCs are theoretical upper limits on a pesticide's
concentration in drinking water in light of total aggregate exposure to
a pesticide in food and residential uses. In calculating a DWLOC, the
Agency determines how much of the acceptable exposure (i.e., the PAD)
is available for exposure through drinking water e.g., allowable
chronic water exposure (mg/kg/day) = cPAD - (average food + residential
exposure). This allowable exposure through drinking water is used to
calculate a DWLOC.
A DWLOC will vary depending on the toxic endpoint, drinking water
consumption, and body weights. Default body weights and consumption
values as used by the EPA's Office of Water are used to calculate
DWLOCs: 2 liter (L)/70 kg (adult male), 2L/60 kg (adult female), and
1L/10 kg (child). Default body weights and drinking water consumption
values vary on an individual basis. This variation will be taken into
account in more refined screening-level and quantitative drinking water
exposure assessments. Different populations will have different DWLOCs.
Generally, a DWLOC is calculated for each type of risk assessment used:
Acute, short-term, intermediate-term, chronic, and cancer.
When EECs for surface water and ground water are less than the
calculated DWLOCs, OPP concludes with reasonable certainty that
exposures to the pesticide in drinking water (when considered along
with other sources of exposure for which OPP has reliable data) would
not result in unacceptable levels of aggregate human health risk at
this time. Because OPP considers the aggregate risk resulting from
multiple exposure pathways associated with a pesticide's uses, levels
of comparison in drinking water may vary as those uses change. If new
uses are added in the future, OPP will reassess the potential impacts
of residues of the pesticide in drinking water as a part of the
aggregate risk assessment process.
1. Acute risk. An acute risk assessment was not performed; there
were no studies that identify an acute hazard based on toxic effects
observed following a single oral exposure (dose) of tribenuron methyl.
[[Page 56716]]
2. Chronic risk. Using the exposure assumptions described in this
unit for chronic exposure, EPA has concluded that exposure to
tribenuron methyl from food will utilize < 1% of the cPAD for the U.S.
population, < 1% of the cPAD for all infants < 1 year old, and < 1% of the
cPAD for children 3 to 5 years old. There are no residential uses for
tribenuron methyl that result in chronic residential exposure to
tribenuron methyl. In addition, there is potential for chronic dietary
exposure to tribenuron methyl in drinking water. After calculating
DWLOCs and comparing them to the EECs for surface and ground water, EPA
does not expect the aggregate exposure to exceed 100% of the cPAD, as
shown in the following Table 3:
Table 3.--Aggregate Risk Assessment for Chronic (Non-Cancer) Exposure to Tribenuron Methyl
----------------------------------------------------------------------------------------------------------------
Surface Ground
Population Subgroup cPAD mg/kg/ % cPAD Water EEC Water EEC Chronic
day (Food) (ppb) (ppb) DWLOC (ppb)
----------------------------------------------------------------------------------------------------------------
U. S. Population 0.008 < 1 .413 .000006 300
------------------------------------------------
All infants < 1 year old 0.008 < 1 .413 .000006 100
------------------------------------------------
Children 1-2 years old 0.008 < 1 .413 .000006 100
------------------------------------------------
Children 3-5 years old 0.008 < 1 .413 .000006 100
------------------------------------------------
Females 13-49 years old 0.008 < 1 .413 .000006 200
----------------------------------------------------------------------------------------------------------------
3. Short-term risk. Short-term aggregate exposure takes into
account residential exposure plus chronic exposure to food and water
(considered to be a background exposure level).
Tribenuron methyl is not registered for use on any sites that would
result in residential exposure. Therefore, the aggregate risk is the
sum of the risk from food and water, which do not exceed the Agency's
level of concern.
4. Intermediate-term risk. Intermediate-term aggregate exposure
takes into account residential exposure plus chronic exposure to food
and water (considered to be a background exposure level).
Tribenuron methyl is not registered for use on any sites that would
result in residential exposure. Therefore, the aggregate risk is the
sum of the risk from food and water, which do not exceed the Agency's
level of concern.
5. Aggregate cancer risk for U.S. population. The Agency considers
the chronic aggregate risk assessment, making use of the cPAD, to be
protective of any aggregate cancer risk. See Table 3, Unit III.E.2.
Therefore, the aggregate risk is not expected to exceed the Agency`s
level 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, and to infants and children from aggregate
exposure to tribenuron methyl residues.
IV. Other Considerations
A. Analytical Enforcement Methodology
Adequate analytical methodology including liquid chromatography
with a photoconductivity detector; high-performance liquid
chromatography with UV detection (HPLC/UV); and gas chromatography
using mass spectral detection (GC/MS) are available for enforcement of
reassessed tolerances. These methods are published in PAM II.
Adequate enforcement methodology --liquid chromatography with
detection via electospray mass spectroscopy is available to enforce the
tolerance expression for canola, flax, and cotton. 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
The maximum residue level (MRL) in Canada for tribenuron methyl on
canola is 0.1 ppm. Available residue data and use pattern support a
U.S. tolerance of 0.02 ppm. No Mexican or Codex MRLs exist for
tribenuron methyl on canola. There are no Canadian, Mexican, or Codex
MRLs for tribenuron methyl on cotton or flax.
C. Conditions
Based on the tolerance reassessment for barley, oats, and wheat,
residue data are required for barley, hay; oat forage and hay; and
wheat forage and hay. Submission of this data and proposal of
appropriate tolerances will be required. There are no conditions of
registration for the establishment of tolerances on canola, cotton, or
flax.
V. Conclusion
Therefore, the tolerance is established for residues of tibenuron
methyl, methyl 2-[[[[(4-methoxy-6-methyl-1, 3, 5-triazin-2-yl)
methylamino]carbobyl]amino] sulfonyl]benzoate, in or on canola, seed at
0.02 ppm; cotton, gin byproducts at 0.02 ppm; cotton, undelinted seed
at 0.02 ppm, and flax, seed at 0.02 ppm. This action results in the
reassessment of 8 tolerances as follows: barley, grain at 0.05 ppm;
barley, straw at 0.10 ppm; oat, grain at 0.05 ppm; oat, straw at 0.1
ppm; wheat, grain at 0.05 ppm; wheat, straw at 0.10 ppm; and tolerances
with regional registration for grass, forage, fodder, and hay group
(except bermudagrass); forage at 0.10 ppm; and grass, forage, fodder,
and hay group (except bermudagrass); hay at 0.10 ppm listed in 40 CFR
180.451. Also, even though many of the tolerancs for the current
commodities listed in Sec. 180.451 have not been changed and only
tolerances for canola, seed; cotton, gin byproducts; cotton, undelinted
seed; and flax, seed are being added, EPA is printing Sec. 180.451 in
its entirety to restructure the section so that it matched the other
sections in subpart C.
VI. Objections and Hearing Requests
Under section 408(g) of FFDCA, as amended by FQPA, any person may
file an objection to any aspect of this regulation and may also request
a hearing on those objections. The EPA procedural regulations which
govern the submission of objections and requests for hearings appear in
40 CFR part 178. Although the procedures in those regulations require
some modification to reflect the amendments made to FFDCA by FQPA, EPA
will continue to use those procedures, with appropriate adjustments,
until the necessary modifications can be made. The new section 408(g)
of FFDCA provides essentially the same process for persons to
``object'' to a regulation for an exemption from the requirement of a
[[Page 56717]]
tolerance issued by EPA under new section 408(d) of FFDCA, as was
provided in the old sections 408 and 409 of FFDCA. However, the period
for filing objections is now 60 days, rather than 30 days.
A. What Do I Need to Do To File an Objection or Request a Hearing?
You must file your objection or request a hearing on this
regulation in accordance with the instructions provided in this unit
and in 40 CFR part 178. To ensure proper receipt by EPA, you must
identify docket ID number OPP-2004-0278. in the subject line on the
first page of your submission. All requests must be in writing, and
must be mailed or delivered to the Hearing Clerk on or before November
22, 2004.
1. Filing the request. Your objection must specify the specific
provisions in the regulation that you object to, and the grounds for
the objections (40 CFR 178.25). If a hearing is requested, the
objections must include a statement of the factual issues(s) on which a
hearing is requested, the requestor's contentions on such issues, and a
summary of any evidence relied upon by the objector (40 CFR 178.27).
Information submitted in connection with an objection or hearing
request may be claimed confidential by marking any part or all of that
information as CBI. Information so marked will not be disclosed except
in accordance with procedures set forth in 40 CFR part 2. A copy of the
information that does not contain CBI must be submitted for inclusion
in the public record. Information not marked confidential may be
disclosed publicly by EPA without prior notice.
Mail your written request to: Office of the Hearing Clerk (1900L),
Environmental Protection Agency, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460-0001. You may also deliver your request to the
Office of the Hearing Clerk in Suite 350, 1099 14th St., NW.,
Washington, DC 20005. The Office of the Hearing Clerk is open from 8
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The
telephone number for the Office of the Hearing Clerk is (202) 564-6255.
2. Copies for the Docket. In addition to filing an objection or
hearing request with the Hearing Clerk as described in Unit VI.A., you
should also send a copy of your request to the PIRIB for its inclusion
in the official record that is described in ADDRESSES. Mail your
copies, identified by docket ID number OPP-2004-0278, to: Public
Information and Records Integrity Branch, Information Resources and
Services Division (7502C), Office of Pesticide Programs, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001. In person or by courier, bring a copy to the location of the
PIRIB described in ADDRESSES. You may also send an electronic copy of
your request via e-mail to: opp-docket@epa.gov. Please use an ASCII
file format and avoid the use of special characters and any form of
encryption. Copies of electronic objections and hearing requests will
also be accepted on disks in WordPerfect 6.1/8.0 or ASCII file format.
Do not include any CBI in your electronic copy. You may also submit an
electronic copy of your request at many Federal Depository Libraries.
B. When Will the Agency Grant a Request for a Hearing?
A request for a hearing will be granted if the Administrator
determines that the material submitted shows the following: There is a
genuine and substantial issue of fact; there is a reasonable
possibility that available evidence identified by the requestor would,
if established resolve one or more of such issues in favor of the
requestor, taking into account uncontested claims or facts to the
contrary; and resolution of the factual issues(s) in the manner sought
by the requestor would be adequate to justify the action requested (40
CFR 178.32).
VII. Statutory and Executive Order Reviews
This final rule establishes a tolerance 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 rule has been
exempted from review under Executive Order 12866 due to its lack of
significance, this rule is not subject to Executive Order 13211,
Actions Concerning Regulations That Significantly Affect Energy Supply,
Distribution, or Use (66 FR 28355, May 22, 2001). This final rule does
not contain any information collections subject to OMB approval under
the Paperwork Reduction Act (PRA), 44 U.S.C. 3501 et seq., or impose
any enforceable duty or contain any unfunded mandate as described under
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA) (Public Law
104-4). Nor does it require any special considerations under Executive
Order 12898, entitled Federal Actions to Address Environmental Justice
in Minority Populations and Low-Income Populations (59 FR 7629,
February 16, 1994); or OMB review or any Agency action under Executive
Order 13045, entitled Protection of Children from Environmental Health
Risks and Safety Risks (62 FR 19885, April 23, 1997). This action does
not involve any technical standards that would require Agency
consideration of voluntary consensus standards pursuant to section
12(d) of the National Technology Transfer and Advancement Act of 1995
(NTTAA), Public Law 104-113, section 12(d) (15 U.S.C. 272 note). Since
tolerances and exemptions that are established on the basis of a
petition under 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. In addition, the Agency has determined that this
action will not have a substantial direct effect on States, on the
relationship between the national government and the States, or on the
distribution of power and responsibilities among the various levels of
government, as specified in Executive Order 13132, entitled Federalism
(64 FR 43255, August 10, 1999). Executive Order 13132 requires EPA to
develop an accountable process to ensure ``meaningful and timely input
by State and local officials in the development of regulatory policies
that have federalism implications.'' ``Policies that have federalism
implications'' is defined in the Executive order to include regulations
that have ``substantial direct effects on the States, on the
relationship between the national government and the States, or on the
distribution of power and responsibilities among the various levels of
government.'' This final rule directly regulates growers, food
processors, food handlers and food retailers, not States. This action
does not alter the relationships or distribution of power and
responsibilities established by Congress in the preemption provisions
of section 408(n)(4) of FFDCA. For these same reasons, the Agency has
determined that this rule does not have any ``tribal implications'' as
described in Executive Order 13175, entitled Consultation and
Coordination with Indian Tribal Governments (65 FR 67249, November 6,
2000). Executive Order 13175, requires EPA to develop an accountable
process to ensure ``meaningful and timely input by tribal officials in
the development of regulatory policies that have tribal implications.''
``Policies that have tribal implications'' is defined in the Executive
order to include regulations that have ``substantial direct effects on
one or more Indian tribes, on the
[[Page 56718]]
relationship between the Federal Government and the Indian tribes, or
on the distribution of power and responsibilities between the Federal
Government and Indian tribes.'' This rule will not have substantial
direct effects on tribal governments, on the relationship between the
Federal Government and Indian tribes, or on the distribution of power
and responsibilities between the Federal Government and Indian tribes,
as specified in Executive Order 13175. Thus, Executive Order 13175 does
not apply to this rule.
VIII. Congressional Review Act
The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. EPA will submit a report containing this rule and other
required information to the U.S. Senate, the U.S. House of
Representatives, and the Comptroller General of the United States prior
to publication of this final rule in the Federal Register. This final
rule is not a ``major rule'' as defined by 5 U.S.C. 804(2).
List of Subjects in 40 CFR Part 180
Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and
recordkeeping requirements.
Dated: September 10, 2004.
Lois Rossi,
Director, Registration Division, Office of Pesticide Programs.
0
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 180.451 is revised to read as follows:
Sec. 180.451 Tribenuron methyl; tolerances for residues.
(a) General. Tolerances are established for the residues of the
herbicide tribenuron methyl (methyl-2-[[[[N-(4-methoxy-6-methyl-1,3,5-
triazin-2-yl) methylamino] carbonyl]amino]sulfonyl] benzoate) in or on
the following raw agricultural commodities:
------------------------------------------------------------------------
Parts per
Commodity million
------------------------------------------------------------------------
Barley, grain.............................................. 0.05
Barley, straw.............................................. 0.10
Canola, seed............................................... 0.02
Cotton, gin byproducts..................................... 0.02
Cotton, undelinted seed.................................... 0.02
Flax, seed................................................. 0.02
Oat, grain................................................. 0.05
Oat, straw................................................. 0.10
Wheat, grain............................................... 0.05
Wheat, straw............................................... 0.10
------------------------------------------------------------------------
(b) Section 18 emergency exemptions. [Reserved]
(c) Tolerances with regional registrations. Tolerances with
regional registration, as defined in Sec. 180.1(n) are established for
residues of the herbicide tribenuron methyl (methyl-2-[[[[N-(4-methoxy-
6-methyl-1,3,5-triazin-2-yl) methylamino] carbonyl]amino]sulfonyl]
benzoate) in or on the following raw agricultural commodities:
------------------------------------------------------------------------
Parts per
Commodity million
------------------------------------------------------------------------
Grass, forage, fodder and hay, group (except Bermudagrass); 0.10
forage....................................................
Grass, forage, fodder and hay, group (except Bermudagrass); 0.10
hay.......................................................
------------------------------------------------------------------------
(d) Indirect or inadvertent residues. [Reserved]
[FR Doc. 04-20982 Filed 9-21-04; 8:45 am]
BILLING CODE 6560-50-S