Federal Register: August 2, 2001 (Volume 66, Number 149)
DOCID: FR Doc 01-19325
ENVIRONMENTAL PROTECTION AGENCY
Environmental Protection Agency
CFR Citation: 40 CFR Part 180
RIN ID: RIN 2070-AB78
OPP ID: [OPP-301148; FRL-6791-7]
NOTICE: RULES
ACTION: Pesticides; tolerances in food, animal feeds, and raw agricultural commodities:
DOCUMENT ACTION: Final rule.
SUBJECT CATEGORY:
Tepraloxydim; Pesticide Tolerance
DATES: This regulation is effective August 2, 2001. Objections and requests for hearings, identified by docket control number OPP301148, must be received by EPA on or before October 1, 2001.
DOCUMENT SUMMARY:
This regulation establishes a tolerance for combined residues
of tepraloxydim (2[1[[[(2E)3chloro2propenyl]oxy]imino]propyl]3 hydroxy5(tetrahydro2Hpyran4yl)cyclohexene1one) and its
metabolites convertible to GP (3 (tetrahydropyran4yl)pentane1,5
dioic acid) and OHGP (3hydroxy3(tetrahydropyran4yl)pentane1,5
dioic acid), calculated as tepraloxydim, in or on canola, seed; [[Page 40142]]
cotton, undelinted seed; cotton, gin byproducts; soybean, seed;
soybean, hulls; and soybean, aspirated grain fractions; and the
combined residues of tepraloxydim and its metabolites convertible to
GP, OHGP, and GL (3(2oxotetrahydropyran4yl)pentane1,5dioic
acid), calculated as tepraloxydim, in or on milk; meat of cattle,
goats, hogs, horses, and sheep; meat byproduct (except kidney) of
cattle, goats, hogs, horses, and sheep; kidney of cattle, goats, hogs,
horses, and sheep; fat of cattle, goats, hogs, horses, and sheep;
poultry, meat; poultry, meat byproducts (except liver), poultry, fat;
poultry, liver, and eggs. Nippon Soda Company, Ltd requested this
tolerance under the Federal Food, Drug, and Cosmetic Act, as amended by
the Food Quality Protection Act of 1996.
SUMMARY:
Tepraloxydim,
SUPPLEMENTAL INFORMATION
I. General Information
A. Does this Action Apply to Me?
You may be affected by this action if you are an agricultural producer, food manufacturer, or pesticide manufacturer. Potentially affected categories and entities may include, but are not limited to: Examples of Potentially Categories NAICS Affected Entities Industry 111 Crop production 112 Animal production 311 Food manufacturing 32532 Pesticide manufacturing
This listing is not intended to be exhaustive, but rather provides
a guide for readers regarding entities likely to be affected by this
action. Other types of entities not listed in the table could also be
affected. The North American Industrial Classification System (NAICS)
codes have been provided to assist you and others in determining
whether or not this action might apply to certain entities. If you have
questions regarding the applicability of this action to a particular
entity, consult the person listed under FOR FURTHER INFORMATION CONTACT.
B. How Can I Get Additional Information, Including Copies of this Document and Other Related Documents?
1. Electronically.You may obtain electronic copies of this document, and certain other related documents that might be available electronically, from the EPA Internet Home Page at http://www.epa.gov/. To access this document, on the Home Page select ``Laws and Regulations'', ``Regulations and Proposed Rules,'' and then look up the entry for this document under the ``Federal RegisterEnvironmental Documents.'' You can also go directly to the Federal Register listings at http://www.epa.gov/fedrgstr/. To access the OPPTS Harmonized Guidelines referenced in this document, go directly to the guidelines at http://www.epa.gov/opptsfrs/home/guidelin.htm. A frequently updated electronic version of 40 CFR part 180 is available at http:// www.access.gpo.gov/nara/cfr/cfrhtml_180/Title_40/40cfr180_00.html, a beta site currently under development.
2. In person. The Agency has established an official record for this action under docket control number OPP301148. The official record consists of the documents specifically referenced in this action, and other information related to this action, including any information claimed as Confidential Business Information (CBI). This official record includes the documents that are physically located in the docket, as well as the documents that are referenced in those documents. The public version of the official record does not include any information claimed as CBI. The public version of the official record, which includes printed, paper versions of any electronic comments submitted during an applicable comment period is available for inspection in the Public Information and Records Integrity Branch (PIRIB), Rm. 119, Crystal Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA, from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The PIRIB telephone number is (703) 3055805. II. Background and Statutory Findings
In the Federal Register of December 22, 1999 64 FR 71774) (FRL 63986), EPA issued a notice pursuant to section 408 of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a as amended by the Food Quality Protection Act of 1996 (FQPA) (Public Law 104170) announcing the filing of a pesticide petition (PP 8F4945) for tolerance by BASF Corporation, acting as agent for Nippon Soda Company, Ltd., P.O. Box 13528, Research Triangle Park, NC 277093528. This notice included a summary of the petition prepared by Nippon Soda, the registrant. There were no comments received in response to the notice of filing.
The petition requested that 40 CFR part 180 be amended by
establishing a tolerance for combined residues of the herbicide
tepraloxydim, (2[1[[[(2E)3chloro2propenyl]oxy]imino]propyl]3 hydroxy5(tetrahydro2Hpyran4yl)cyclohexene1one) and its
metabolites convertible to GP (3(tetrahydropyran4yl)pentane1,5
dioic acid) and OHGP (3hydroxy3(tetrahydropyran4yl)pentane1,5
dioic acid) (calculated as the herbicide) in or on the raw agricultural
commodities cotton, seed at 0.2 part per million (ppm); cotton meal at
0.2 ppm, cotton gin trash at 3.0 ppm; soybean seed at 5.0 ppm; soybean
hulls, poultry meat and fat at 0.5 ppm; and poultry, liver at 1.0 ppm; and eggs at 0.2 ppm.
During the course of the review, the Agency determined that the
available data support the following tolerances: tepraloxydim (2[1
[[[(2E)3chloro2propenyl]oxy]imino]propyl]3hydroxy5(tetrahydro
2Hpyran4yl)cyclohexene1one) and its metabolites convertible to GP
(3(tetrahydropyran4yl)pentane1,5dioic acid) and OHGP (3hydroxy 3(tetrahydropyran4yl)pentane1,5dioic acid), calculated as
tepraloxydim, in or on cotton, undelinted seed at 0.2 ppm; cotton, gin
byproducts at 3.0 ppm; soybean, seed at 6.0 ppm; soybean, hulls at 8.0
ppm; and soybean, aspirated grain fractions at 1200 ppm; and the
combined residues of tepraloxydim and its metabolites convertible to
GP, OHGP, and GL (3(2oxotetrahydropyran4yl)pentane1,5dioic
acid), calculated as tepraloxydim, in or on milk at 0.1 ppm; meat of
cattle, goats, hogs, horses, and sheep at 0.2 ppm; meat byproduct
(except kidney) of cattle, goats, hogs, horses, and sheep at 0.2 ppm;
kidney of cattle, goats, hogs, horses, and sheep at 0.5 ppm; fat of
cattle, goats, hogs, horses, and sheep at 0.15 ppm; poultry, meat at 0.2 ppm; poultry, meat byproducts (except liver)
[[Page 40143]]
at 0.2 ppm; poultry, fat at 0.3 ppm; poultry, liver at 1.0 ppm; and
eggs at 0.20 ppm. The available data also support the establishment of
a tolerance with regional registration, as defined in Sec. 180.1(n) for
the combined residues of tepraloxydim and its metabolites convertible
to GP and OHGP, calculated as tepraloxydim in or on the raw agricultural commodity canola, seed at 0.5 ppm.
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....''
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) (FRL57547).
III. Aggregate Risk Assessment and Determination of Safety
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 and to
make a determination on aggregate exposure, consistent with section
408(b)(2), for a tolerance[s] for the combined residues of tepraloxydim (2[1[[[(2E)3chloro2 propenyl]oxy]imino]propyl]3hydroxy5
(tetrahydro2Hpyran4yl)cyclohexene1one) and its metabolites
convertible to GP (3(tetrahydropyran4yl)pentane1,5dioic acid) and OHGP (3hydroxy3(tetrahydropyran4yl)pentane1,5dioic acid),
calculated as tepraloxydim, in or on cotton, undelinted seed at 0.2
ppm; cotton, gin byproducts at 3.0 ppm; soybean, seed at 6.0 ppm;
soybean, hulls at 8.0 ppm; soybean, aspirated grain fractions at 1200
ppm; and the combined residues of tepraloxydim and its metabolites
convertible to GP, OHGP, and GL (3(2oxotetrahydropyran4yl)pentane
1,5 dioic acid), calculated as tepraloxydim, in or on milk at 0.1 ppm;
meat of cattle, goats, hogs, horses, and sheep at 0.2 ppm; meat
byproduct (except kidney) of cattle, goats, hogs, horses, and sheep at
0.2 ppm; kidney of cattle, goats, hogs, horses, and sheep at 0.5 ppm;
fat of cattle, goats, hogs, horses, and sheep at 0.15 ppm; poultry,
meat at 0.2 ppm; poultry, meat byproducts (except liver) at 0.2 ppm;
poultry, fat at 0.3 ppm; poultry, liver at 1.0 ppm; and eggs at 0.20
ppm; and a tolerance with regional registration, as defined in
Sec. 180.1(n) for the combined residues of tepraloxydim and its
metabolites convertible to GP and OHGP, calculated as tepraloxydim, in
or on the raw agricultural commodity canola, seed at 0.5 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 tepraloxydim are
discussed in the following Table 1 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
Guideline No. Study Type Results
870.3100 90Day oral toxicity in NOAEL = M=22, F=26 mg/kg/day rats
LOAEL = M=223, F=257 mg/kg/day based on
decreased body weight/body weight gain,
changes in kidney proximal tubule, and
changes in clinical chemistry parameters
indicative of liver and kidney impairment.
870.3150 90Day oral toxicity in NOAEL = M=12.9, F=14.3 mg/kg/day dogs
LOAEL = M=63.3, F=68.0 mg/kg/day based on
increased liver and thyroid weights and
histopathology of spleen.
870.3200 28Day dermal toxicity in NOAEL = 1,000 mg/kg/day (limit dose) rats
LOAEL = Not determined.
870.3700a Prenatal developmental in Maternal NOAEL = 120 mg/kg/day rats
LOAEL = 360 mg/kg/day based on decreased
body weight and food consumption.
Developmental NOAEL = 40 mg/kg/day
LOAEL = 120 mg/kg/day based on decreased
fetal body weight, retarded ossification,
and hydroureter.
870.3700b Prenatal developmental in Maternal NOAEL = 60 mg/kg/day; LOAEL = 180
rabbits mg/kg/day based on decreased body weight
and food consumption.
Developmental NOAEL = 180 mg/kg/day (HTD)
LOAEL = >180 mg/kg/day based on no
developmental effects at the HTD.
870.3800 Reproduction and fertility Parental/Systemic NOAEL = M=50.6, F=55.0 mg/
effects in rats kg/day [[Page 40144]]
LOAEL = M= 260.0, F= 276.0 mg/kg/day based
on decreased body weight/ weight gain and
food consumption.
Reproductive NOAEL = 260 mg/kg/day
LOAEL = > 260 mg/kg/day based on no
reproductive effects.
Offspring NOAEL = M=50.6, F=55.0 mg/kg/day
LOAEL = M= 260.0, F= 276.0 mg/kg/day based
on reduced pup body weight gain and lower
pup body weight during lactation.
870.4100b Chronic toxicity in dogs NOAEL = M=11.5, F=12.5 mg/kg/day
LOAEL = M=56.0, F=60.6 mg/kg/day based on
reduced epididymal and prostate
activities, transitional epithelial
hyperplasia of the urinary bladder, and
abnormal liver function and liver foci.
870.4200 Carcinogenicity in rats NOAEL = M=5, F=38 mg/kg/day
LOAEL = M=30, F=272 mg/kg/day based on
hepatic lesions in both sexes, increased
incidences of hepatocellular adenoma/
carcinoma in females, adrenal medullary
tumors in females, and uterine schwannoma
in females.
Some evidence of carcinogenicity in females
870.4300 Carcinogenicity in mice NOAEL = M=37, F=52 mg/kg/day
LOAEL = M=332, F=490 mg/kg/day based on
decreased body weight/gain, increased
relative liver weight in males, and
uterine sclerosis.
Female mice developed liver tumors at an
excessively toxic dose.
870.5100 Gene Mutation Ames test: Negative at all doses; cytotoxic
at HTD of 5,000
LOAEL = 500 mg/kg based on decreased motor
activity.
870.6200b Subchronic neurotoxicity NOAEL = M=103, F=124 mg/kg/day
screening battery (unacceptable)
LOAEL = M=428, F=513 mg/kg/day based on
increased motor activity, and decreased
body weight, food consumption, food
efficiency.
870.7485 Metabolism and In pharmacokinetics/metabolism studies in
pharmacokinetics the rat, tepraloxydim was readily and
almost completely absorbed after oral
administration (single dose of 30 or 300
mg/kg), but was rapidly excreted mainly
via the urine (6580%). Excretion was
nearly 23 fold higher in the bile than
the feces, which suggests enterohepatic
recirculation. The rat plasma half life of
radiolabeled tepraloxydim is nearly 4.4
and 10 hours at the low and high dose,
respectively. No accumulation of
radioactivity was observed in any tissue
at 120 hours postdosing. A large number
of metabolites were detected in the urine,
feces, and bile; the main metabolic
pathway being oxidation at the pyran ring
to the lactone via a hydroxy metabolite,
and cleavage of the oxime ether group with
the imine and oxazol as products. At near
plasma t
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
[[Page 40145]]
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 intra species differences.
For dietary risk assessment (other than cancer) the Agency uses the UF to calculate an acute or chronic reference dose (acute RfD or chronic RfD) where the RfD is equal to the NOAEL divided by the appropriate UF (RfD = NOAEL/UF). Where an additional safety factor is retained due to concerns unique to the FQPA, 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 FQPA Safety Factor.
For nondietary 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 is expressed as 1 x 10\6\ or one in a million).
Under certain specific circumstances, MOE calculations will be used for
the carcinogenic risk assessment. In this nonlinear 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 (MOE
Table 2. Summary of Toxicological Dose and Endpoints for tepraloxydim for Use in Human Risk Assessment
Dose (mg/kg/day), Population (if Study and Toxicological
Exposure Scenario Uncertainty Factor (UF) applicable); Endpoint Effects
Acute Dietary NOAEL = 40; UF = 100; Females 1350: Reduced Developmental Toxicity
FQPA* = 3X; Females 13 fetal body weight, Rat
50 ONLY. reduced ossification
indicative of delayed
maturation, and the
occurrence of
hydroureter at 120 mg/
kg/day (LOAEL).
General Population:
This risk assessment
is not required. No
appropriate single
dose endpoint.
Acute RfD = 0.4 mg/kg
Acute PAD = 0.13 mg/kg/
day (Females 1350
ONLY)
Chronic Dietary NOAEL = 5 UF = 100; NOAEL = 100 ppm (5 mg/ CarcinogenicityRat
FQPA = 1X kg/day) based on male
liver microscopic
lesions (eosinophilic
foci) at 600 ppm (30
mg/kg/day).
Chronic RfD = 0.05 mg/
kg/day
Incidental Oral, ShortTerm NOAEL = 120; FQPA = 1X Reduced maternal body Developmental Toxicity
weight gain and food Rat
consumption at 360 mg/
kg/day (LOAEL).
Incidental Oral, IntermediateTerm NOAEL = 22; FQPA = 1X NOAEL = 300 ppm (males Subchronic Oral
22, females 26 mg/kg/ ToxicityRat
day) based on reduced
body weight/body
weight gain, proximal
tubule kidney changes
in males, and clinical
chemistry changes
indicative of hepatic
and kidney impairment
in both sexes at 3000
ppm (223 and 257 mg/kg/
day.
Dermal, Short and IntermediateTerm NOAEL = 40 Reduced fetal body Developmental Toxicity
weight, reduced Rat
ossification
indicative of delayed
maturation, and the
occurrence of
hydroureter at 120 mg/
kg/day (LOAEL). The
dermal absorption
factor of 36% should
be used for routeto
route extrapolation.
Dermal, LongTerm NOAEL= N/A This risk assessment N/A
is not required due to
the seasonal use of
the chemical.
Inhalation, Shortand Intermediate NOAEL= 40 Reduced fetal body Developmental Toxicity
Term weight, reduced Rat
ossification
indicative of delayed
maturation, and the
occurrence of
hydroureter at 120 mg/
kg/day (LOAEL). Use
routetoroute
extrapolation and a
100% absorption rate
(default value).
Inhalation, LongTerm NOAEL = N/A This risk assessment N/A
is not required due to
the seasonal use of
the chemical.
\*\ The reference to the FQPA Safety Factor refers to any additional safety factor retained due to concerns unique to the FQPA.
[[Page 40146]]
C. Exposure Assessment
1. Dietary exposure from food and feed uses. Tolerances have been
not established (40 CFR part 180) for the combined residues of
tepraloxydim and its metabolites, in or on a variety of raw
agricultural commodities. Risk assessments were conducted by EPA to
assess dietary exposures from tepraloxydim in food as follows:
i. Acute exposure. Acute dietary risk assessments are performed
for a fooduse 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. The Dietary Exposure Evaluation Model (DEEM
In conducting this acute dietary risk assessment, the Agency has made highly conservative assumptions. Default concentration factors were used for the processed commodities. One hundred percent of the proposed crops are assumed to be treated with tepraloxydim and residues were assumed to be at tolerance levels. This is expected to result in an overestimate of dietary exposure. Therefore, this acute dietary (food only) risk assessment should be viewed as a highly conservative risk estimate. The percent aPAD that would be above EPA`s level of concern would be 100%. Percent crop treated (PCT) and/or anticipated residues were not used. A DEEM acute analysis was performed using proposed and recommended tolerance levels for the combined residues of tepraloxydim and its metabolites for females (1350 years old). Based on the results of this analysis, exposure to tepraloxydim from food will utilize 4.4% of aPAD for females (1350 years old), the only population subgroup of concern.
ii. Chronic exposure. In conducting this chronic dietary risk
assessment the DEEM
In conducting this chronic dietary risk assessment, the Agency has made highly conservative assumptions which result in an overestimate of human dietary exposure. A DEEM chronic exposure analysis was performed using the proposed tolerance level residues and 100% of the crop treated to estimate the exposure for the general population and subgroups of interest. This is expected to result in an overestimate of dietary risk. Therefore, this chronic dietary (food only) risk assessment should be viewed as a highly conservative risk estimate. Thus, in making a safety determination for these tolerances, EPA takes into account this highly conservative exposure assessment. The Agency is generally concerned with chronic exposures that exceed 100% of the cPAD or chronic RfD. Percent crop and/or anticipated residues were not used. Based on this analysis the exposure to tepraloxydim from food will utilize 6.8% cPAD for the general population, 31% cPAD for all infants (>1 year old), 15% cPAD for children (16 old), 10% cPAD for children (712 old), 7.4% cPAD for males (1319 old), and 5.0% for females (1350 old) and males (20+ years old).
iii. Cancer. Tepraloxydim has been reviewed by the Agency for carcinogenicity classification. In accordance with the EPA Draft Guidelines for Carcinogenic Risk Assessment (July, 1999), the Agency has classified tepraloxydim as data are inadequate for an assessment of human carcinogenic potential because some evidence is suggestive of carcinogenic effects, but other equally pertinent evidence does not confirm a concern. The Agency concluded that quantification of human cancer risk is not required because although there was some evidence of carcinogenicity in female rats based on an increased incidence of liver tumors at the high dose, this finding was not supported by the results of the chronic study. The Agency also concluded that female mice developed liver tumors at an excessively toxic dose, and although male mice had nonneoplastic liver changes similar to or exceeding those seen in female mice at the same dose, there was no increase in liver tumor incidence in males. Further more tepraloxydim was not mutagenic in a battery of assays. Therefore a cancer risk assessment was not performed.
2. Dietary exposure from drinking water. The Agency lacks sufficient monitoring exposure data to complete a comprehensive dietary exposure analysis and risk assessment for tepraloxydim 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 tepraloxydim.
The Agency uses the Generic Estimated Environmental Concentration (GENEEC) or the Pesticide Root Zone/Exposure Analysis Modeling System (PRZM/EXAMS) to estimate pesticide concentrations in surface water and SCIGROW, which predicts pesticide concentrations in groundwater. In general, EPA will use GENEEC (a tier 1 model) before using PRZM/EXAMS (a tier 2 model) for a screeninglevel assessment for surface water. The GENEEC model is a subset of the PRZM/EXAMS model that uses a specific highend runoff scenario for pesticides. GENEEC incorporates a farm pond scenario, while PRZM/EXAMS incorporate an index reservoir environment in place of the previous pond scenario. The PRZM/EXAMS model includes 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 coarse screen for sorting out pesticides for which it is highly unlikely that drinking water concentrations would ever 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) from these models to quantify
drinking water exposure and risk as a %RfD or %PAD. Instead, drinking water levels of
[[Page 40147]]
comparison (DWLOCs) are calculated and used as a point of comparison
against the model estimates of a pesticide's concentration in water.
DWLOCs are theoretical upper limits 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 tepraloxydim they are further discussed in the aggregate risk sections below.
Based on the GENEEC and SCIGROW models the EECs of tepraloxydim
for acute exposures are estimated to be 17.6
3. From nondietary exposure. The term ``residential exposure'' is used in this document to refer to nonoccupational, nondietary exposure (e.g., for lawn and garden pest control, indoor pest control, termiticides, and flea and tick control on pets).
Tepraloxydim is not registered for use on any sites that would result in residential exposure.
4. Cumulative exposure to substances with a 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 tepraloxydim 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, tepraloxydim 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 tepraloxydim 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 final rule for Bifenthrin Pesticide Tolerances (62 FR 62961, November 26, 1997). D. Safety Factor for Infants and Children
1. Safety factor for infants and childrenIn general. 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 prenatal and postnatal toxicity and the completeness of the database on toxicity and exposure 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.
2. Prenatal and postnatal sensitivity. Based on the available data, both quantitative and qualitative evidence of increased susceptibility was observed following in utero tepraloxydim exposure to rats. In the prenatal rat developmental toxicity study, the developmental toxicity NOAEL/LOAEL is below the maternal toxicity NOAEL/LOAEL. Additionally, the developmental effects observed (reduced fetal body weights, retarded ossification indicative of delayed maturation, and the occurrence of hydroureter) were considered to be more severe than those observed in maternal animals (decreased body weight gain and food consumption). No evidence of increased susceptibility was seen following pre/post natal exposure in the 2generation reproduction study.
3. Conclusion. The toxicology database for tepraloxydim is complete
except for a developmental neurotoxicity study which is required due to
evidence of neurotoxicity (effects on motor activity and grip strength)
observed in acute and subchronic neurotoxicity studies with adult
animals and a 28day inhalation toxicity study is required because
there is no inhalation toxicity available for risk assessment. The
exposure data are complete or are estimated based on data that
reasonably accounts for potential exposures. EPA determined that the
10X safety factor to protect infants and children should be reduced to
3x for tepraloxydim. The Agency concluded that a safety factor is
required for tepraloxydim since there is evidence of increased
susceptibility of the young demonstrated in the prenatal developmental
study in rats. The Committee recommended that the FQPA safety factor be
reduced to 3x because: the toxicology database is complete; the
requirement of a developmental neurotoxicity study is not based on
criteria reflecting special concern for the developing fetuses or young
which are generally used for requiring a DNT study and a safety
factor (e.g.: neuropathy in adult animals; CNS malformations following
prenatal exposure; brain weight or sexual maturation changes in
offspring; and/or functional changes in offspring) and therefore does
not warrant an FQPA safety factor\1\; the dietary (food and drinking
water) exposure assessments will not underestimate the potential
exposures for infants and children; and there are currently no residential uses.
\1\ This is an interim step towards accordance with the proposed
OPP Policy on Determination of the Appropriate FQPA Safety Factor(s)
for Use in the ToleranceSetting Process' which was presented to the
FIFRA SAP meeting in May, 1999 and placed in the Docket for Public Comment (64 FR 37001, July 8, 1999; Docket No. 37001).
The FQPA safety factor for tepraloxydim is applicable to only
Females 1350 years population subgroup for acute dietary risk
assessment (there are currently no residential exposure scenarios),
since there is concern for increased susceptibility of the young
demonstrated in the prenatal developmental study in rats. The
developmental effects are presumed to occur following a single exposure
of females of childbearing age and, therefore, are appropriate for risk assessment for females aged 1350 years old.
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 which are used as a point of comparison against the model estimates of a pesticide's concentration in water (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 USEPA Office of Water are used to calculate
DWLOCs: 2L/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 screeninglevel and quantitative
[[Page 40148]]
drinking water exposure assessments. Different populations will have
different DWLOCs. Generally, a DWLOC is calculated for each type of
risk assessment used: acute, shortterm, intermediateterm, chronic, and cancer.
When EECs for surface water and groundwater are less than the calculated DWLOCs, the Office of Pesticide Programs 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. Using the exposure assumptions discussed in this
unit for acute exposure, the acute dietary exposure from food to
tepraloxydim will occupy 4.4% of the aPAD for females 13 years and
older. In addition, there is potential for acute dietary exposure to
tepraloxydim 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 aPAD, as shown in the following Table 3:
Table 3. Aggregate Risk Assessment for Acute Exposure to Tepraloxydim
Surface Ground Water
aPAD (mg/ % aPAD Water EEC EEC (
2. Chronic risk. Using the exposure assumptions described in this
unit for chronic exposure, EPA has concluded that exposure to
teparloxydim from food will utilize 6.8% of the cPAD for the U.S.
population, 31% of the cPAD for all infants (< 1 year old and 15% of
the cPAD for children (16 years old) and 5.0% of the cPAD for females
(1350 years old). There are no residential uses for tepraloxydim that
result in chronic residential exposure to tepraloxydim. In addition,
there is potential for chronic dietary exposure to tepraloxydim 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 4:
Table 4. Aggregate Risk Assessment for Chronic (NonCancer) Exposure to Tepraloxydim
Surface Ground Water Chronic
cPAD mg/kg/ % cPAD Water EEC EEC (
3. Shortterm risk. Shortterm aggregate exposure takes into account residential exposure plus chronic exposure to food and water (considered to be a background exposure level).
Tepraloxydim 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. Intermediateterm risk. Intermediateterm aggregate exposure takes into account residential exposure plus chronic exposure to food and water (considered to be a background exposure level).
Tepraloxydim 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. Tepraloxydim has been
reviewed by the Agency for carcinogenicity classification. In
accordance with the EPA Draft Guidelines for Carcinogenic Risk
Assessment (July, 1999), the Agency has classified tepraloxydim as data
are inadequate for an assessment of human carcinogenic potential
because some evidence is suggestive of carcinogenic effects, but other
equally pertinent evidence does not confirm a concern. The Agency
concluded that quantification of human cancer risk is not required
because although there was some evidence of carcinogenicity in female
rats based on an increased incidence of liver tumors at the high dose,
this finding was not supported by the results of the chronic study. The
Agency also concluded that female mice developed liver tumors at an
excessively toxic dose, and although male mice had nonneoplastic liver
changes similar to or exceeding those seen in female mice at the same
dose, there was no increase in liver tumor incidence in males. Further
more, tepraloxydim was not mutagenic in a battery of assays. Therefore a cancer risk assessment was not performed.
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 tepraloxydim residues.
IV. Other Considerations
A. Analytical Enforcement Methodology
Analytical methods (gas chromotography (GC/MS (selected ion
monitoring)) have been proposed as analytical enforcement methods by
the petitioner for raw agricultural, processed, and livestock
commodities. These methods have been validated by the petitioner for
gathering residue data. The initial raw agricultural commodity method
has a longer completion time than currently permitted by current EPA
Guidelines. A shorter, improved method for agricultural commodities and the
[[Page 40149]]
livestock commodity methods are being evaluated by EPA`s Analytical
Chemistry Branch. Prior to publication in PAM II and upon request, the
analytical methods will be available from the Analytical Chemistry
Branch (ACB), Biological and Economic Analysis Division (BEAD),
Environmental Sciences Center, 701 Mapes Road, Fort George C. Meade, MD
207555350, contact Frances D. Griffith Jr., telephone (4103052905,
email griffith,frances@epa.gov. The analytical standards for these
methods are also available from EPA`s National Pesticide Standard
Repository at the same location. Successful completion of method trials
for proposed analytical methods are a condition of registration B. International Residue Limits
There are no Codex, Canadian, or Mexican maximum residue limits
(MRLs) established for tepraloxydim. Harmonization is not an issue at this time.
C. Conditions
The following are conditions of registration.
1. Successful completion of method trials for the proposed analytical enforcement methods.
2. A regional registration for canola in the states of Minnesota, Montana, North Dakota, and South Dakota.
3. Submission of additional storage stability data are needed to support the ruminant feeding study (samples stored for 217337 days) and Agency review of storage stability data currently under review.
4. Submission of a developmental neurotoxicity study.
5. Submission of a 28day inhalation toxicity study. V. Conclusion
Therefore, the tolerance is established for combined residues of
tepraloxydim (2[1[[[(2E)3chloro2propenyl]oxy]imino]propyl]3 hydroxy5(tetrahydro2Hpyran4yl)cyclohexene1one) and its
metabolites convertible to GP (3(tetrahydropyran4yl)pentane1,5
dioic acid) and OHGP (3hydroxy3 (tetrahydropyran4yl)pentane1,5
dioic acid), calculated as tepraloxydim, in or on cotton, undelinted
seed at 0.2 ppm; cotton, gin byproducts at 3.0 ppm; soybean, seed at
6.0 ppm; soybean, hulls at 8.0 ppm; soybean, aspirated grain fractions
at 1,200 ppm; and the combined residues of tepraloxydim and its
metabolites convertible to GP, OHGP, and GL (3(2oxotetrahydropyran
4yl)pentane1,5dioic acid), calculated as tepraloxydim, in or on milk
at 0.1 ppm; meat of cattle, goats, hogs, horses, and sheep at 0.2 ppm;
meat byproduct (except kidney) of cattle, goats, hogs, horses, and
sheep at 0.2 ppm; kidney of cattle, goats, hogs, horses, and sheep at
0.5 ppm; fat of cattle, goats, hogs, horses, and sheep at 0.15 ppm;
poultry, meat at 0.2 ppm; poultry, meat byproducts (except liver) at
0.2 ppm; poultry, fat at 0.3 ppm; poultry, liver at 1.0 ppm; and eggs
at 0.20 ppm; and a tolerance with regional registration, as defined in
Sec. 180.1 (n) for the combined residues of tepraloxydim and its
metabolites convertible to GP and OHGP, calculated as tepraloxydim, in
or on the raw agricultural commodity canola, seed at 0.5 ppm. VI. Objections and Hearing Requests
Under section 408(g) of the FFDCA, as amended by the FQPA, any
person may file an objection to any aspect of this regulation and may
also request a hearing on those objections. The EPA procedural
regulations which govern the submission of objections and requests for
hearings appear in 40 CFR part 178. Although the procedures in those
regulations require some modification to reflect the amendments made to
the FFDCA by the FQPA of 1996, EPA will continue to use those
procedures, with appropriate adjustments, until the necessary
modifications can be made. The new section 408(g) provides essentially
the same process for persons to ``object'' to a regulation for an
exemption from the requirement of a tolerance issued by EPA under new
section 408(d), as was provided in the old FFDCA sections 408 and 409.
However, the period for filing objections is now 60 days, rather than 30 days.
A. What Do I Need to Do to File an Objection or Request a Hearing?
You must file your objection or request a hearing on this regulation in accordance with the instructions provided in this unit and in 40 CFR part 178. To ensure proper receipt by EPA, you must identify docket control number OPP301148 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 October 1, 2001.
1. Filing the request. Your objection must specify the specific provisions in the regulation that you object to, and the grounds for the objections (40 CFR 178.25). If a hearing is requested, the objections must include a statement of the factual issues(s) on which a hearing is requested, the requestor's contentions on such issues, and a summary of any evidence relied upon by the objector (40 CFR 178.27). Information submitted in connection with an objection or hearing request may be claimed confidential by marking any part or all of that information as CBI. Information so marked will not be disclosed except in accordance with procedures set forth in 40 CFR part 2. A copy of the information that does not contain CBI must be submitted for inclusion in the public record. Information not marked confidential may be disclosed publicly by EPA without prior notice.
Mail your written request to: Office of the Hearing Clerk (1900), Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460. You may also deliver your request to the Office of the Hearing Clerk in Rm. C400, Waterside Mall, 401 M St., SW., Washington, DC 20460. The Office of the Hearing Clerk is open from 8 a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Office of the Hearing Clerk is (202) 2604865.
2. Tolerance fee payment. If you file an objection or request a hearing, you must also pay the fee prescribed by 40 CFR 180.33(i) or request a waiver of that fee pursuant to 40 CFR 180.33(m). You must mail the fee to: EPA Headquarters Accounting Operations Branch, Office of Pesticide Programs, P.O. Box 360277M, Pittsburgh, PA 15251. Please identify the fee submission by labeling it ``Tolerance Petition Fees.''
EPA is authorized to waive any fee requirement ``when in the judgement of the Administrator such a waiver or refund is equitable and not contrary to the purpose of this subsection.'' For additional information regarding the waiver of these fees, you may contact James Tompkins by phone at (703) 3055697, by email at tompkins.jim@epa.gov, or by mailing a request for information to Mr. Tompkins at Registration Division (7505C), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460.
If you would like to request a waiver of the tolerance objection fees, you must mail your request for such a waiver to: James Hollins, Information Resources and Services Division (7502C), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460.
3. Copies for the Docket. In addition to filing an objection or
hearing request with the Hearing Clerk as described in Unit 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 Unit I.B.2. Mail your
copies, identified by docket control number OPP301148, to: Public
Information and Records Integrity Branch, Information Resources and [[Page 40150]]
Services Division (7502C), Office of Pesticide Programs, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460.
In person or by courier, bring a copy to the location of the PIRIB
described in Unit I.B.2. You may also send an electronic copy of your
request via email to: oppdocket@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 issue(s) in the manner sought by the requestor would be adequate to justify the action requested (40 CFR 178.32).
VII. Regulatory Assessment Requirements
This final rule establishes a tolerance under FFDCA section 408(d) 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). 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 1044). Nor does it require any special considerations under Executive Order 12898, entitled Federal Actions to Address Environmental Justice in Minority Populations and LowIncome 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 104113, section 12(d) (15 U.S.C. 272 note). Since tolerances and exemptions that are established on the basis of a petition under FFDCA section 408(d), 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 def
FOR FURTHER INFORMATION CONTACT
By mail: Jim Tompkins, Registration
Division (7505C), Office of Pesticide Programs, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW.,Washington, DC 20460; telephone number: (703) 3055697 ; and email address:
tompkins.jim@epa.gov.