Tebuconazole; Pesticide Tolerance

Note: EPA no longer updates this information, but it may be useful as a reference or resource.
 [Federal Register: January 8, 1999 (Volume 64, Number 5)]
[Rules and Regulations]               
[Page 1132-1138]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08ja99-17]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-300768; FRL 6050-5]
RIN 2070-AB78

 
Tebuconazole; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes tolerances for residues of 
tebuconazole in or on grapes, grass forage, grass hay, grass seed 
screenings, grass straw, milk, meat by-products of cattle, goats, 
horses and sheep. Bayer Corporation requested these tolerances under 
the Federal Food, Drug and Cosmetic Act (FFDCA), as amended by the Food 
Quality Protection Act of 1996 (Pub. L. 104-170).
DATES: This regulation is effective January 8, 1999. Objections and 
requests for hearings must be received by EPA on or before March 9, 
1999.

ADDRESSES: Written objections and hearing requests, identified by the 
docket control number, [OPP-300768], must be submitted to: Hearing 
Clerk (1900), Environmental Protection Agency, Rm. M3708, 401 M St., 
SW., Washington, DC 20460. Fees accompanying objections and hearing 
requests shall be labeled ``Tolerance Petition Fees'' and forwarded to: 
EPA Headquarters Accounting Operations Branch, OPP (Tolerance Fees), 
P.O. Box 360277M, Pittsburgh, PA 15251. A copy of any objections and 
hearing requests filed with the Hearing Clerk identified by the docket 
control number, [OPP-300768], must also be submitted to: Public 
Information and Records Integrity Branch, Information Resources and 
Services Division (7502C), Office of Pesticide Programs, Environmental 
Protection Agency, 401 M St., SW., Washington, DC 20460. In person, 
bring a copy of objections and hearing requests to Rm. 119, Crystal 
Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA.
    A copy of objections and hearing requests filed with the Hearing 
Clerk may also be submitted electronically by sending electronic mail 
(e-mail) to: opp-docket@epamail.epa.gov. Copies of objections and 
hearing requests must be submitted as an ASCII file avoiding the use of 
special characters and any form of encryption. Copies of objections and 
hearing requests will also be accepted on disks in WordPerfect 5.1/6.1 
or ASCII file format. All copies of objections and hearing requests in 
electronic form must be identified by the docket control number [OPP-
300768]. No Confidential Business Information (CBI) should be submitted 
through e-mail. Electronic copies of objections and hearing requests on 
this rule may be filed online at many Federal Depository Libraries.

FOR FURTHER INFORMATION CONTACT: By mail: Mary Waller, Registration 
Division (7505C), Office of Pesticide Programs, Environmental 
Protection Agency, 401 M St., SW., Washington, DC 20460. Office 
location, telephone number, and e-mail address: Crystal Mall #2, 1921 
Jefferson Davis Hwy., Arlington, VA, (703) 308-9354; e-mail: 
waller.mary@epamail.epa.gov.

SUPPLEMENTARY INFORMATION: In the Federal Register of February 2, 1997, 
(62 FR 16590) (5F4577) and of March 5, 1997, (62 FR 10047) (6F4669), 
EPA issued notices pursuant to section 408 of the Federal Food, Drug, 
and Cosmetic Act (FFDCA), 21 U.S.C. 346a(e) announcing the filing of 
pesticide petitions (PP) for tolerances by Bayer Corporation, 8400 
Hawthorne Road, Kansas City, MO, 64120-0013 (amended in a letter from 
Bayer Corporation to EPA dated September 18, 1998). These notices 
included summaries of the petitions prepared by Bayer Corporation, the 
registrant. There were no comments received in response to the notice 
of filing.
    The petitions requested that 40 CFR 180.474 be amended by 
establishing tolerances for residues of the fungicide, tebuconazole 
(alpha-[2-(4-chlorophenyl)-ethyl]-alpha-(1,1-dimethylethyl)-1H-1,2,4-
triazole-1-ethanol) in or on grapes at 5 parts per million (ppm), grass 
forage at 8 ppm, grass hay at 25 ppm, grass seed screenings at 55 ppm, 
grass straw at 30 ppm, and by establishing tolerances for the combined 
residues of tebuconazole and its 1-(4-chlorophenyl)-4,4-dimethyl-3-(1H-
1,2,4-triazole-1-yl-methyl)-pentane-3,5-diol metabolite (HWG 2061), 
hereafter referred to in this document as tebuconazole, in milk at 0.1 
ppm, and meat by-products of cattle, horses, goats and sheep at 0.2 
ppm.

I. Risk Assessment and Statutory Findings

    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) (FRL-5754-7).

II. 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 
tebuconazole and to make a determination on aggregate exposure, 
consistent with section 408(b)(2), for tolerances for residues of 
tebuconazole in or on grapes, grass forage, grass hay, grass seed 
screenings, grass straw, milk, meat by-products of cattle, horses, 
goats and sheep. EPA's assessment of the dietary exposures and risks 
associated with establishing the tolerance follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its 
validity, completeness, and reliability as well as the relationship of 
the results of the studies to human risk. EPA has also considered 
available information concerning the variability of the

[[Page 1133]]

sensitivities of major identifiable subgroups of consumers, including 
infants and children. The nature of the toxic effects caused by 
tebuconazole is discussed below.
    1. Acute toxicity. Tebuconazole exhibits moderate toxicity. The rat 
acute oral LD<INF>50</INF> = 3,933 milligram/kilogram (mg/kg) (category 
III); the rabbit acute dermal LD<INF>50</INF>>5,000 mg/kg (category 
IV); and the rat acute inhalation LC<INF>50</INF>>0.371 milligram/Liter 
(mg/L) (category II). Technical tebuconazole was slightly irritating to 
the eye (category III) and was not a skin irritant (category IV) in 
rabbits. Tebuconazole was not a dermal sensitizer.
    2. Subchronic toxicity--i. In a 90-day oral feeding study, rats 
were administered technical tebuconazole at levels of 0, 100, 400, or 
1,600 ppm (0, 8, 34.8, or 171.7 mg/kg/day for males or 0, 10.8, 46.5, 
or 235.2 mg/kg/day for females). In males, the no observed adverse 
effect level (NOAEL) was 34.8 mg/kg/day and the lowest observed adverse 
effect level (LOAEL) was 171.7 mg/kg/day based on decreased body weight 
and decreased body weight gain, adrenal vacuolation and spleen 
hemosiderosis. In females, the NOAEL was 10.8 mg/kg/day and the LOAEL 
of 46.5 mg/kg/day was based on adrenal vacuolation.
    ii. In a 90-day oral feeding study, Beagle dogs were administered 
technical tebuconazole at levels of 0, 200, 1,000, or 5,000 ppm (0, 74, 
368, or 1,749 mg/kg/day for males or 0, 73, 352, or 1,725 mg/kg/day for 
females). In females, the NOAEL was 73 mg/kg/day and the LOAEL was 352 
mg/kg/day based on decreased body weight and decreased body weight 
gain, decreased food consumption and increased liver N-demethylase 
activity. At the highest dose tested (HDT), lens opacity was seen in 
all males and in one female and cataracts were seen in three females.
     iii. In a 21-day dermal toxicity study, rabbits were exposed 
dermally to technical tebuconazole 5 days a week at doses of 0, 50, 
250, or 1,000 mg/kg/day. No significant systemic effects were seen. The 
systemic NOAEL > 1,000 mg/kg/day.
     iv. In a 21-day inhalation toxicity study, rats were exposed to 
technical tebuconazole (15 exposures - 6 hours/day for 3 weeks) at 
airborne concentrations of 0, 0.0012, 0.0106, or 0.1558 mg/L/day. The 
NOAEL was 0.0106 mg/L/day and the LOAEL was 0.1558 mg/L/day based on 
piloerection and induction of liver N-demethylase.
    3. Chronic toxicity--i. In a 2-year combined chronic feeding/
carcinogenicity study, rats were administered technical tebuconazole at 
levels of 0, 100, 300, or 1,000 ppm (0, 5.3, 15.9, or 55 mg/kg/day for 
males or 0, 7.4, 22.8, or 86.3 mg/kg/day for females). In males, the 
NOAEL was 5.3 mg/kg/day and the LOAEL was 15.9 mg/kg/day based on C-
cell hyperplasia in the thyroid gland. In females, the NOAEL was 7.4 
mg/kg/day and the LOAEL was 22.8 mg/kg/day based on body weight 
depression, decreased hemoglobin, hematocrit, mean corpuscular volume 
and mean corpuscular hemoglobin concentration and increased liver 
microsomal enzymes. No evidence of carcinogenicity was found at the 
levels tested.
     ii. In a 1-year chronic feeding study, Beagle dogs were 
administered technical tebuconazole at levels of 0, 40, 200, or 1,000 
(weeks 1-39) and 2,000 ppm (weeks 40-52) (0, 1, 5 or 25/50 mg/kg/day 
for males and females). The NOAEL was 1 mg/kg/day and the LOAEL was 5 
mg/kg/day based on ocular lesions (lenticular and corneal opacity) and 
hepatic toxicity (changes in the appearance of the liver and increased 
siderosis).
     iii. In a 1-year chronic feeding study, Beagle dogs were 
administered technical tebuconazole at levels of 0, 100, or 150 ppm (0, 
3.0, or 4.4 mg/kg/day for males or 0, 3.0 or 4.5 mg/kg/day for 
females). The NOAEL was 3.0 mg/kg/day and the LOAEL was 4.4 mg/kg/day 
based on adrenal affects in both sexes. In males there was hypertrophy 
of adrenal zona fasciculata cells amounting to 4/4 at 150 ppm and to 0/
4 at 100 ppm and in controls. Other adrenal findings in males included 
fatty changes in the zona glomerulosa (3/4) and lipid hyperplasia in 
the cortex (2/4) at 150 ppm vs. (1/4) for both effects at 100 ppm and 
control dogs. In females there was hypertrophy of zona fasciculata 
cells of the adrenal amounting to 4/4 at 150 ppm and to 0/4 at 100 ppm 
and 1/4 in controls. Fatty changes in the zona glomerulosa of the 
female adrenal amounted to 2/4 at 150 ppm and to 1/4 at 100 ppm and in 
controls.
    4. Carcinogenicity. In a 91-week carcinogenicity study, mice were 
administered technical tebuconazole at levels of 0, 500, or 1,500 ppm 
(0, 84.9, or 279 mg/kg/day for males or 0, 103.1, or 365.5 mg/kg/day 
for females). Neoplastic histopathology consisted of statistically 
significant increased incidences of hepatocellular neoplasms; adenomas 
(35.4%) and carcinomas (20.8%) at 1,500 ppm in males and carcinomas 
(26.1%) at 1,500 ppm in females. Statistically significant decreased 
body weights and increased food consumption were reported that were 
consistent with decreased food efficiency at 500 and 1,500 ppm in males 
and at 1,500 ppm in females. Clinical chemistry values (dose-dependent 
increases in plasma GOT, GPT and Alkaline Phosphatase) for both sexes 
were consistent with hepatotoxic effects at both 500 and 1,500 ppm. 
Relative liver weight increases reached statistical significance at 
both 500 and 1,500 ppm in males and at 1,500 ppm in females. Non-
neoplastic histopathology included dose-dependent increases in hepatic 
pancinar fine fatty vacuolation, statistically significant at 500 and 
1,500 ppm in males and at 1,500 ppm in females. Other histopathology 
included significant oval cell proliferation in both sexes and dose-
dependent ovarian atrophy that was statistically significant at 500 and 
1,500 ppm. The Maximum Tolerated Dose (MTD) was achieved at or around 
500 ppm.
    5. Developmental toxicity--i. In a developmental toxicity study, 
pregnant female rats were gavaged with technical tebuconazole at levels 
of 0, 30, 60, or 120 mg/kg/day between days 6 and 15 of gestation. The 
maternal NOAEL was 30 mg/kg/day and the maternal LOAEL was 60 mg/kg/day 
based on increased absolute and relative liver weights. The 
developmental NOAEL was 30 mg/kg/day and the developmental LOAEL was 60 
mg/kg/day based on delayed ossification of thoracic, cervical and 
sacral vertebrae, sternum and limbs plus an increase in supernumerary 
ribs.
     ii. In a developmental toxicity study, pregnant female rabbits 
were gavaged with technical tebuconazole at levels of 0, 10, 30, or 100 
mg/kg/day between days 6 and 18 of gestation. The maternal NOAEL was 30 
mg/kg/day and the maternal LOAEL was 100 mg/kg/day based on minimal 
depression of body weight gains and food consumption. The developmental 
NOAEL was 30 mg/kg/day and the developmental LOAEL was 100 mg/kg/day 
based on increased postimplantation losses, malformations in 8 fetuses 
out of 5 litters (including peromelia in 5 fetuses/4 litters; 
palatoschisis in 1 fetus/1 litter), hydrocephalus and delayed 
ossification.
     iii. In a developmental toxicity study, pregnant female mice were 
gavaged with technical tebuconazole at levels of 0, 10, 30, or 100 mg/
kg/day between days 6 and 15 of gestation (part 1 of study) or at 
levels of 0, 10, 20, 30, or 100 mg/kg/day between days 6 and 15 of 
gestation (part 2 of study). The maternal NOAEL was 10 mg/kg/day and 
the maternal LOAEL was 20 mg/kg/day. Maternal toxicity (hepatocellular 
vacuolation and elevations in AST, ALP and alkaline phosphatase) 
occurred at

[[Page 1134]]

all dose levels but was minimal at 10 mg/kg/day. Reduction in mean 
corpuscular volume in parallel with reduced hematocrit occurred at 
doses greater than or equal to 20 mg/kg/day. The liver was the target 
organ. The developomental NOAEL was 10 mg/kg/day and the developmental 
LOAEL was 30 mg/kg/day based on an increase in the number of runts.
    iv. In a developmental toxicity study, pregnant female mice were 
administered dermal doses of technical tebuconazole applied at levels 
of 0, 100, 300, or 1,000 mg/kg/day between days 6 and 15 of gestation. 
Equivocal maternal toxicity was observed 1,000 mg/kg/day.The maternal 
NOAEL was <nearly-eq> 1,000 mg/kg/day. The developmental NOAEL was 
1,000 mg/kg/day.
    v. In a 2-generation reproduction study, rats were fed technical 
tebuconazole at levels of 0, 100, 300, or 1,000 ppm, (0, 5, 15, or 50 
mg/kg/day, males and females). The parental maternal NOAEL was 15 mg/
kg/day and the parental LOAEL was 50 mg/kg/day based on depressed body 
weights, increased spleen hemosiderosis and decreased liver and kidney 
weights. The reproductive NOAEL was 15 mg/kg/day and the reproductive 
LOAEL of 50 mg/kg/day based on decreased pup body weights from birth 
through 3 - 4 weeks.
    6. Mutagenicity. An Ames test with Salmonella sp., a mouse 
micronucleus assay, a sister chromatid exchange assay with Chinese 
hamster ovary cells, and an unscheduled DNA synthesis assay with rat 
hepatocytes provided no evidence of mutagenicity.
    7. Dermal penetration. Radio-labeled technical tebuconazole in 
ethanol was applied dermally to rats in doses of 0.604, 5.85, 52.4, or 
547 micrograms per square centimeter (<greek-m>g/cm<SUP>2</SUP>). The 
percent of dose absorbed after 24 hours amounted to 27.77, 27.06, 
23.01, and 6.38% of the applied dose, respectively. The amount which 
remained on the application site after soap and water wash increased 
with the dose and amounted at 24 hours to 24.7, 24.4, 32.02, and 53.11% 
of the above applied doses, respectively. The percent of the dose 
absorbed after 8 hours was 49.9% at the dose of 0.604 <greek-m>g/
cm<SUP>2</SUP>. The ethanol used as a solvent may have led to an 
overestimate of absorption.
    8. Neurotoxicity. No acute or subchronic neurotoxicity studies are 
available for tebuconazole. In a battery of subchronic and chronic 
studies, there were no indications of treatment-related effects on the 
central or peripheral nervous system of experimental animals. In the 
prenatal developmental toxicity studies, however, several effects on 
the fetal nervous system were noted. These effects included alterations 
in the development of the fetal nervous system in mice (increased 
malformations of the brain and spinal column, and exencephaly), in rats 
(anophthalmia), and in rabbits (neural tubule defects characterized as 
meningocoele and spina bifida, and hydrocephalus).
    9. General metabolism. Rats were gavaged with 1 or 20 mg/kg radio-
labeled technical tebuconazole. 98.1 % of the oral dose was absorbed. 
Within 72 hours of dosing, over 87% of the dose was excreted in urine 
and feces. At sacrifice (72 hours post dosing), total residue (-GI 
tract) amounted to 0.63% of the dose. A total of 10 compounds were 
identified in the excreta. A large fraction of the identified 
metabolites corresponded to successive oxidations steps of a methyl 
group of the test material. At 20 mg/kg, changes in detoxication 
patterns may be occurring.

B. Toxicological Endpoints

    1. Acute toxicity. EPA selected the NOAEL of 10 mg/kg/day from a 
developmental toxicity study in mice based on an increased incidence of 
runts observed at the LOAEL of 30 mg/kg/day. The population subgroups 
of concern are females (13+ years), infants, and children. An 
Uncertainty Factor of 100 was used to account for inter-species 
extrapolation and intra-species variability. On this basis, the acute 
Reference dose (RfD) for tebuconazole was calculated to be 0.10 mg/kg/
day. EPA determined that a 10 x FQPA safety factor is applicable to the 
subpopulations females (13+ years), as well as infants and children 
because the effects seen were developmental, the severity of observed 
effects and the effects are presumed to occur following ``acute'' 
exposures. A dose and toxicity endpoint were not identified for the 
general population.
     2. Short - and intermediate - term toxicity. No short - 
intermediate - or long-term dermal toxicity endpoints were identified. 
For short - intermediate - and long-term inhalation toxicity, the NOAEL 
of 0.0106 mg/L/day from the 21-day rat inhalation toxicity study was 
selected for risk assessment. The LOAEL of 0.1558 mg/L/day was based on 
induction of liver microsomal enzymes and piloerection.
    3. Chronic toxicity. EPA established the RfD for tebuconazole at 
0.03 mg/kg/day. The RfD is based on a 1-year feeding study in dogs in 
which the NOAEL was 3.0 mg/kg/day and the LOAEL was 4.4 mg/kg/day based 
on histopathological changes in the adrenal gland. An Uncertainty 
Factor of 100 was used to account for inter-species extrapolation and 
intra-species variability.
    4. Carcinogenicity. EPA concluded that tebuconazole should be 
classified as a Group C - possible human carcinogen and determined that 
the RfD approach be used to estimate human risk. A statistically 
significant increase in the incidence of hepatocellular adenomas, 
carcinomas and combined adenoma/carcinomas was observed in male mice at 
the highest dose tested; a statistically significant increase in the 
incidence of hepatocellular carcinomas and combined adenomas/carcinomas 
was observed in female mice at the highest dose tested; and 
tebuconazole was determined to be structurally related to at least six 
other triazole fungicides that also produce hepatocellular tumors in 
male and/or female mice.

C. Exposures and Risks

    1.  From food and feed uses. Tolerances are established under 40 
CFR Sec. 180.474(a) for residues of the fungicide tebuconazole in or on 
bananas at 0.05 ppm, barley forage, hay and straw at 0.10, barley grain 
at 0.05 ppm, cherries at 4.0 ppm, oat forage, hay and straw at 0.10 
ppm, oat grain at 0.05 ppm, peaches (includes nectarines) at 1.0 ppm, 
peanuts at 0.1 ppm, peanut hulls at 4.0 ppm, wheat forage, hay, and 
straw at 0.10 ppm, and wheat grain at 0.05 ppm. Time-limited tolerances 
for section 18 emergency exemptions are established under 40 CFR 
Sec. 180.474(b)(1) for residues of the fungicide tebuconazole in or on 
barley grain at 2.0 ppm, barley hay and straw at 20 ppm; pistachios at 
1.0 ppm, wheat hay at 15 ppm, and wheat straw at 2.0 ppm. Time-limited 
tolerances for section 18 emergency exemptions are established under 40 
CFR Sec. 180.474(b)(2) for residues of the fungicide tebuconazole in or 
on milk at 0.1 ppm; cattle, goats, hogs, horses, poultry, and sheep 
meat byproducts at 0.2 ppm. Risk assessments were conducted by EPA to 
assess dietary exposures from tebuconazole as follows.
     Section 408(b)(2)(E) authorizes EPA to use available data and 
information on the anticipated residue levels of pesticide residues in 
food and the actual levels of pesticide chemicals that have been 
measured in food. If EPA relies on such information, EPA must require 
that data be provided 5 years after the tolerance is established, 
modified, or left in effect, demonstrating that the levels in food are 
not above the levels anticipated. Following the initial data 
submission, EPA is authorized to require similar data on a time frame 
it deems appropriate. As required by

[[Page 1135]]

section 408(b)(2)(E), EPA will issue a data call-in for information 
relating to anticipated residues to be submitted no later than 5 years 
from the date of issuance of this tolerance.
    i.  Acute exposure and risk. Acute dietary risk assessments are 
performed for a food-use pesticide if a toxicological study has 
indicated the possibility of an effect of concern occurring as a result 
of a one day or single exposure. The acute dietary (food only) risk 
assessment used a highly refined Monte Carlo analysis based on the 
following assumptions: percent crop treated data were used for all 
commodities; maximum residue levels from crop field trials for single 
serving commodities such as bananas and peaches were utilized; average 
residue levels from crop field trials were used for blended commodities 
such as fruit juices, grains and oils; anticipated residue levels for 
ruminant commodities were calculated using a livestock diet constructed 
from anticipated residue levels for livestock feed items. Application 
of the 10 x safety factor to the Acute RfD of 0.10 mg/kg/day results in 
an acceptable acute dietary risk of 10% or less of the Acute RfD for 
the following subpopulations of concern: 8.5% for children (1 to 6 
years); 7.4% for non-nursing infants (<1 year); 7% for all infants (<1 
year); 6.7% for nursing infants (<1 year); and 3.3% for children (7 to 
12 years) and females (13+ years). Application of the 10 x safety 
factor to the Acute RfD results in an acceptable acute dietary exposure 
of 10% or less of the Acute RfD.
    ii. Chronic exposure and risk. The chronic dietary (food only) risk 
assessment used the RfD of 0.03 mg/kg/day. EPA used the Dietary 
Exposure Evaluation Model (DEEM) which utilized data from the USDA 
1989-91 Continuing Survey of Food Intake by Individuals (CSFII). The 
risk assessment is very conservative and uses the Theoretical Maximum 
Residue Concentration (TMRC) which assumes that 100% of all treated 
food and/or feed commodities having tebuconazole tolerances will 
contain tebuconazole residues at the tolerance level. EPA generally has 
no concern for exposures below 100% of the chronic RfD (when the FQPA 
factor has been removed) because this RfD represents the level at or 
below which daily aggregate dietary exposure over a lifetime will not 
pose appreciable risks to human health. The Agency has estimated that 
chronic dietary exposure to tebuconazole from food only will utilize 
12% of the chronic RfD for the population subgroup, U.S. Population, 
and the maximum percent of the chronic RfD (41%) is utilized by 
children (1-6 years).
    2. From drinking water. There are no monitoring data for residues 
of tebuconazole in ground water. No health advisory levels or Maximum 
Contaminant Levels for residues of tebuconazole in drinking water have 
been established. Tebuconazole is persistent and relatively immobile in 
water.
     The Agency used the Screening Concentration in Ground Water (SCI-
GROW) screening model to determine the Estimated Environmental 
Concentration (EEC) of 0.3 <greek-m>g/L of tebuconazole in ground water 
for both chronic and acute analysis. SCI-GROW is an empirical model 
based upon actual ground water monitoring data collected from the 
registration of a number of pesticides that serve as benchmarks for the 
model. SCI-GROW provides realistic estimates of pesticide 
concentrations in shallow, highly vulnerable ground water sites (i.e., 
sites with sand soils and depth to ground water of 10 to 20 feet). EPA 
compares drinking water levels of concern (DWLOC) directly with the 
SCI-GROW model values.
     The Agency used the Generic Estimated Environmental Concentration 
(GENEEC) screening model to determine the surface water acute EEC of 14 
<greek-m>g/L (peak) and the surface water chronic EEC of 10 <greek-m>g/
L (avg 56-day concentration). GENEEC is used to estimate pesticide 
concentrations in surface water for up to 56 days after a single runoff 
event. GENEEC provides an upper-bound concentration value and can 
substantially overestimate (by a <ls-thn-eq> 3-fold factor) true 
pesticide concentrations in drinking water. EPA applies a factor of 3 
to GENEEC model values when determining whether or not a level of 
concern has been exceeded. If the GENEEC model value is <ls-thn-eq> 3 
times the DWLOC, the pesticide is considered to have passed the screen 
and no further assessment is needed.
    i. Acute exposure and risk. The acute DWLOC is 200 <greek-m>g/L for 
females (13+ years old) and 14 <greek-m>g/L for infants/children. The 
EEC's for acute analysis of water are 0.3 <greek-m>g/L (ground water) 
and 14 <greek-m>g/L (surface water). EPA does not expect the acute 
aggregate exposure to exceed 10% of the acute RfD. Therefore, EPA 
concludes with reasonable certainty that no harm will result to the 
subpopulations of concern, females (13+ years old), or infants and 
children from aggregate exposure to residues of tebuconazole.
    ii. Chronic exposure and risk. The chronic DWLOC is 910 <greek-m>g/
L for the U.S. population, 720 <greek-m>g/L for females (13+ years, 
nursing), and 190 <greek-m>g/L for infants/children. The EEC's for 
chronic analysis of water are 0.3 <greek-m>g/L (ground water) and 10 
<greek-m>g/L (surface water). EPA does not expect the chronic aggregate 
exposure to exceed 100% of the chronic RfD. Therefore, EPA concludes 
with reasonable certainty that no harm will result from chronic (non-
cancer) aggregate exposure to tebuconazole residues.
    3. From non-dietary exposure. Tebuconazole is currently registered 
for use on the following residential non-food sites: the formulation of 
wood-based composite products, wood products for in-ground contact, 
plastics, exterior paints, glues and adhesives. Exposure via incidental 
ingestion (by children) and inhalation are not a concern for these 
products which are used outdoors. No paints or other end-use products 
containing tebuconazole are available for interior use. Thus, no risk 
is expected for residential nonfood sites.
    4. Cumulative exposure to substances with common mechanism of 
toxicity. Section 408(b)(2)(D)(v) requires that, when considering 
whether to establish, modify, or revoke a tolerance, the Agency 
consider ``available information'' concerning the cumulative effects of 
a particular pesticide's residues and ``other substances that have a 
common mechanism of toxicity.''
    EPA does not have, at this time, available data to determine 
whether tebuconazole has a common mechanism of toxicity with other 
substances or how to include this pesticide in a cumulative risk 
assessment. Unlike other pesticides for which EPA has followed a 
cumulative risk approach based on a common mechanism of toxicity, 
tebuconazole does not appear to produce a toxic metabolite produced by 
other substances. For the purposes of this tolerance action, therefore, 
EPA has not assumed that tebuconazole has a common mechanism of 
toxicity with other substances. For 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. Aggregate Risks and Determination of Safety for U.S. Population

    1. Acute risk. Application of the 10x safety factor for enhanced 
susceptibility of infants and children to the Acute RfD of 0.1 mg/kg/
day results in an acceptable acute dietary exposure of 10% or less of 
the Acute RfD for the subpopulations of concern, females (13+ years), 
infants and children. The acute

[[Page 1136]]

DWLOC for females (13+ years) is 200 <greek-m>g/L and for infants/
children is 14 <greek-m>g/L. These values are higher than the SCI-GROW 
EEC value of 0.3 <greek-m>g/L for ground water and the GENEEC acute EEC 
of 14 <greek-m>g/L for surface water (peak value) when divided by 
three. Therefore, EPA concludes with reasonable certainty that the 
potential risks from aggregate acute exposure (food & water) would not 
exceed the Agency's level of concern.
    2. Chronic risk. Using the TMRC exposure assumptions described 
above, EPA has concluded that aggregate exposure to tebuconazole from 
food will utilize 12% of the RfD for the U.S. population. The major 
identifiable subgroup with the highest aggregate exposure is children 
1-6 years old, as discussed below. EPA generally has no concern for 
exposures below 100% of the RfD because the RfD represents the level at 
or below which daily aggregate dietary exposure over a lifetime will 
not pose appreciable risks to human health. Despite the potential for 
exposure to tebuconazole in drinking water and from non-dietary, non-
occupational exposure, EPA does not expect the aggregate exposure to 
exceed 100% of the RfD. EPA concludes that there is reasonable 
certainty that no harm will result from aggregate exposure to 
tebuconazole residues.
    3. Aggregate cancer risk for U.S. population. EPA classified 
tebuconazole as a Group C - possible human carcinogen and determined 
that the RfD approach be used to estimate the carcinogenic risk to 
humans. Risk concerns for carcinogenicity due to long-term consumption 
of tebuconazole residues are adequately addressed by the aggregate 
chronic exposure analysis using the chronic RfD. Therefore, EPA 
concludes that there is reasonable certainty that no harm will result 
from aggregate exposure to tebuconazole residues.
    4. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
from aggregate exposure to tebuconazole residues.

E. Aggregate Risks and Determination of Safety for Infants and Children

    1. Safety factor for infants and children--i. In general. In 
assessing the potential for additional sensitivity of infants and 
children to residues of tebuconazole, EPA considered data from 
developmental toxicity studies in mice, rats, rabbits and a 2-
generation reproduction study in the rat. The developmental toxicity 
studies are designed to evaluate adverse effects on the developing 
organism resulting from maternal pesticide exposure during gestation. 
Reproduction studies provide information relating to effects from 
exposure to the pesticide on the reproductive capability of mating 
animals and data on systemic toxicity.
    FFDCA section 408 provides that EPA shall apply an additional 
tenfold margin of safety for infants and children in the case of 
threshold effects to account for pre-and post-natal toxicity ecies 
variability) and not the additional tenfold MOE/uncertainty factor when 
EPA has a complete data base under existing guidelines and when the 
severity of the effect in infants or children or the potency or unusual 
toxic properties of a compound do not raise concerns regarding the 
adequacy of the standard MOE/safety factor.
    ii. Pre- and post-natal sensitivity. Pre-natal developmental 
toxicity studies indicated several effects on the fetal nervous system. 
These effects included alterations in the development of the fetal 
nervous system in mice (increased malformations of the brain and spinal 
column, and exencephaly), in rats (anophthalmia), and in rabbits 
(neural tubule defects characterized as meningocoele and spina bifida, 
and hydrocephalus). On the basis of comparable developmental and 
maternal NOAEL's and LOAEL's, EPA determined that there was no 
indication of increased sensitivity of the offspring of mice, rats, or 
rabbits to pre-natal or post-matal exposure to tebuconazole. However, 
EPA does note that there is increased sensitivity in the pups based on 
the more severe developmental effects observed at the developmental 
LOAEL's and at higher doses as compared to the maternal effects 
observed at the maternal LOAEL's and at higher doses. EPA also notes 
that tebuconazole is structurally related to several other triazole 
fungicides which have demonstrated a developmental LOAEL below the 
maternal LOAEL in rats and/or rabbits.
    iii. Conclusion. EPA determined that based on the observed fetal 
nervous system effects and the fact that data on several other 
structurally related triazole fungicides indicate neurotoxic effects, a 
developmental neurotoxicity study will be required. Otherwise, there is 
a complete toxicity database for tebuconazole and exposure data is 
complete or is estimated based on data that reasonably accounts for 
potential exposures. EPA determined that the 10x safety factor be 
retained because of the increased sensitivity of pups as demonstrated 
by the severity of the observed developmental effects, evidence of 
alterations in the development of the fetal nervous system, the 
structural relationship of tebuconazole to several other triazole 
fungicides which have been shown to cause developmental effects, and 
the fact that a developmental neurotoxicity study will be required.
    2. Acute risk. EPA determined that the 10x factor to account for 
enhanced sensitivity of infants and children be retained . Application 
of the 10x safety factor to the Acute RfD of 0.10 mg/kg/day results in 
an acceptable acute dietary risk of 10% or less of the Acute RfD for 
the following subpopulations of concern: 8.5% for children (1 to 6 
years); 7.4% for non-nursing infants (<1 year); 7% for all infants (<1 
year); 6.7% for nursing infants (<1 year); and 3.3% for children (7 to 
12 years) and females (13+ years). EPA concludes with reasonable 
certainty that the potential risks from aggregate acute exposure (food 
& water) would not exceed the Agency's level of concern.
    3. Chronic risk. Using the exposure assumptions described above, 
EPA has concluded that the highest aggregate exposure to tebuconazole 
from food will utilize 41% of the RfD for children (1-6 years). EPA 
generally has no concern for exposures below 100% of the RfD because 
the RfD represents the level at or below which daily aggregate dietary 
exposure over a lifetime will not pose appreciable risks to human 
health. Despite the potential for exposure to tebuconazole in drinking 
water and from non-dietary, non-occupational exposure, EPA does not 
expect the aggregate exposure to exceed 100% of the RfD.
    4. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
to infants and children from aggregate exposure to tebuconazole 
residues.

III. Other Considerations

A. Metabolism In Plants and Animals

    The nature of the residue in plants and animals is adequately 
understood. The residue of concern in plants is tebuconazole. The 
residues of concern in animals are the parent compound, tebuconazole, 
and its 1-(4-chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4-triazole-1-yl-
methyl)-pentane-3,5-diol metabolite. Tolerances on animal commodities 
milk at 0.1 ppm, and meat by-products of cattle, horses, goats and 
sheep at 0.2 ppm are required in conjunction with this use.

B. Analytical Enforcement Methodology

     Adequate enforcement methodology (gas chromatography) is available 
to enforce the tolerance expression. The method may be requested from: 
Calvin

[[Page 1137]]

Furlow, PIRIB, IRSD (7502C), Office of Pesticide Programs, 
Environmental Protection Agency, 401 M St., SW., Washington, DC 20460. 
Office location and telephone number: Rm 101FF, Crystal Mall #2, 1921 
Jefferson Davis Hwy., Arlington, VA 22202, (703-305-5229).

C. Magnitude of Residues

    EPA has concluded that residue data submitted in support of the 
tolerances for grapes at 5 ppm, grass forage at 8 ppm, grass hay at 25 
ppm, grass seed screenings at 55 ppm, grass straw at 30 ppm, milk at 
0.1 ppm, and meat by-products of cattle, horses, goats and sheep at 0.2 
ppm indicate that the tolerances requested by the petitioner are 
adequate.

D. International Residue Limits

    There are no established Codex, Canadian, or Mexican MRLs 
established for tebuconazole. A Codex MRL is proposed for residues of 
tebuconazole in or on grapes at 2.0 ppm. There are no proposed MRLs for 
tebuconazole in or on grapes in Canada and Mexico. Tolerance 
compatibility problems do not exist with respect to Mexico or Canada, 
but do exist with respect to the Codex MRL. The submitted residue data 
support a U.S. tolerance level of 5.0 ppm for tebuconazole in/on 
grapes, and it is not possible to harmonize the proposed tolerance for 
residues of tebuconazole in or on grapes with Codex. The higher 
residues in the U.S. may be due to different agricultural practices 
and/or climatic conditions.

E. Rotational Crop Restrictions

    Rotational crop restrictions are not required as rotation to other 
crops in conjunction with the production of grapes and grass grown for 
seed is not considered significant.

IV. Conclusion

    Therefore, the tolerances are established for residues of 
tebuconazole in or on grapes at 5 ppm, grass forage at 8 ppm, grass hay 
at 25 ppm, grass seed screenings at 55 ppm, grass straw at 30 ppm, and 
tolerances are established for the combined residues of tebuconazole, 
and its 1-(4-chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4-triazole-1-yl-
methyl)-pentane-3,5-diol metabolite in milk at 0.1 ppm, and meat by-
products of cattle, horses, goats and sheep at 0.2 ppm.

V. Objections and Hearing Requests

    The new FFDCA section 408(g) provides essentially the same process 
for persons to ``object'' to a tolerance regulation issued by EPA under 
new section 408(e) and (l)(6) as was provided in the old section 408 
and in section 409. However, the period for filing objections is 60 
days, rather than 30 days. EPA currently has procedural regulations 
which govern the submission of objections and hearing requests. These 
regulations will require some modification to reflect the new law. 
However, until those modifications can be made, EPA will continue to 
use those procedural regulations with appropriate adjustments to 
reflect the new law.
    Any person may, by March 9, 1999, file written objections to any 
aspect of this regulation and may also request a hearing on those 
objections. Objections and hearing requests must be filed with the 
Hearing Clerk, at the address given above (40 CFR 178.20). A copy of 
the objections and/or hearing requests filed with the Hearing Clerk 
should be submitted to the OPP docket for this rulemaking. The 
objections submitted must specify the provisions of the regulation 
deemed objectionable and the grounds for the objections (40 CFR 
178.25). Each objection must be accompanied by the fee prescribed by 40 
CFR 180.33. If a hearing is requested, the objections must include a 
statement of the factual issues on which a hearing is requested, the 
requestor's contentions on such issues, and a summary of any evidence 
relied upon by the requestor (40 CFR 178.27). A request for a hearing 
will be granted if the Administrator determines that the material 
submitted shows the following: There is genuine and substantial issue 
of fact; there is a reasonable possibility that available evidence 
identified by the requestor would, if established, resolve one or more 
of such issues in favor of the requestor, taking into account 
uncontested claims or facts to the contrary; and resolution of the 
factual issues in the manner sought by the requestor would be adequate 
to justify the action requested (40 CFR 178.32). Information submitted 
in connection with an objection or hearing request may be claimed 
confidential by marking any part or all of that information as CBI. 
Information so marked will not be disclosed except in accordance with 
procedures set forth in 40 CFR part 2. A copy of the information that 
does not contain CBI must be submitted for inclusion in the public 
record. Information not marked confidential may be disclosed publicly 
by EPA without prior notice.

VI. Public Record and Electronic Submissions

    EPA has established a record for this rulemaking under docket 
control number [OPP-300768] (including any comments and data submitted 
electronically). A public version of this record, including printed, 
paper versions of electronic comments, which does not include any 
information claimed as CBI, is available for inspection from 8:30 a.m. 
to 4 p.m., Monday through Friday, excluding legal holidays. The public 
record is located in Room 119 of the Public Information and Records 
Integrity Branch, Information Resources and Services Division (7502C), 
Office of Pesticide Programs, Environmental Protection Agency, Crystal 
Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA.
    Electronic comments may be sent directly to EPA at:
    opp-docket@epamail.epa.gov.


    Electronic comments must be submitted as an ASCII file avoiding the 
use of special characters and any form of encryption.
    The official record for this rulemaking, as well as the public 
version, as described above will be kept in paper form. Accordingly, 
EPA will transfer any copies of objections and hearing requests 
received electronically into printed, paper form as they are received 
and will place the paper copies in the official rulemaking record which 
will also include all comments submitted directly in writing. The 
official rulemaking record is the paper record maintained at the 
Virginia address in ``ADDRESSES'' at the beginning of this document.

VII. Regulatory Assessment Requirements

A. Certain Acts and Executive Orders

    This final rule establishes tolerances 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) (Pub. L. 104-4). Nor does 
it require any prior consultation as specified by Executive Order 
12875, entitled Enhancing the Intergovernmental Partnership (58 FR 
58093, October 28, 1993), or special considerations as required by 
Executive Order 12898, entitled Federal Actions to

[[Page 1138]]

Address Environmental Justice in Minority Populations and Low-Income 
Populations (59 FR 7629, February 16, 1994), or require OMB review in 
accordance with Executive Order 13045, entitled Protection of Children 
from Environmental Health Risks and Safety Risks (62 FR 19885, April 
23, 1997).
    In addition, since tolerances and exemptions that are established 
on the basis of a petition under FFDCA section 408(d), such as the 
tolerances in this final rule, do not require the issuance of a 
proposed rule, the requirements of the Regulatory Flexibility Act (RFA) 
(5 U.S.C. 601 et seq.) do not apply. Nevertheless, the Agency has 
previously assessed whether establishing tolerances, exemptions from 
tolerances, raising tolerance levels or expanding exemptions might 
adversely impact small entities and concluded, as a generic matter, 
that there is no adverse economic impact. The factual basis for the 
Agency's generic certification for tolerance actions published on May 
4, 1981 (46 FR 24950) and was provided to the Chief Counsel for 
Advocacy of the Small Business Administration.

B. Executive Order 12875

    Under Executive Order 12875, entitled Enhancing the 
Intergovernmental Partnership (58 FR 58093, October 28, 1993), EPA may 
not issue a regulation that is not required by statute and that creates 
a mandate upon a State, local, or tribal government, unless the Federal 
government provides the funds necessary to pay the direct compliance 
costs incurred by those governments. If the mandate is unfunded, EPA 
must provide to OMB a description of the extent of EPA's prior 
consultation with representatives of affected State, local, and tribal 
governments, the nature of their concerns, copies of any written 
communications from the governments, and a statement supporting the 
need to issue the regulation. In addition, Executive Order 12875 
requires EPA to develop an effective process permitting elected 
officials and other representatives of State, local, and tribal 
governments ``to provide meaningful and timely input in the development 
of regulatory proposals containing significant unfunded mandates.''
    Today's rule does not create an unfunded Federal mandate on State, 
local, or tribal governments. The rule does not impose any enforceable 
duties on these entities. Accordingly, the requirements of section 1(a) 
of Executive Order 12875 do not apply to this rule.

C. Executive Order 13084

    Under Executive Order 13084, entitled Consultation and Coordination 
with Indian Tribal Governments (63 FR 27655, May 19,1998), EPA may not 
issue a regulation that is not required by statute, that significantly 
or uniquely affects the communities of Indian tribal governments, and 
that imposes substantial direct compliance costs on those communities, 
unless the Federal government provides the funds necessary to pay the 
direct compliance costs incurred by the tribal governments. If the 
mandate is unfunded, EPA must provide to OMB, in a separately 
identified section of the preamble to the rule, a description of the 
extent of EPA's prior consultation with representatives of affected 
tribal governments, a summary of the nature of their concerns, and a 
statement supporting the need to issue the regulation. In addition, 
Executive Order 13084 requires EPA to develop an effective process 
permitting elected officials and other representatives of Indian tribal 
governments ``to provide meaningful and timely input in the development 
of regulatory policies on matters that significantly or uniquely affect 
their communities.''
    Today's rule does not significantly or uniquely affect the 
communities of Indian tribal governments. This action does not involve 
or impose any requirements that affect Indian tribes. Accordingly, the 
requirements of section 3(b) of Executive Order 13084 do not apply to 
this rule.

VIII. Submission to Congress and the Comptroller General

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. EPA will submit a report containing this rule and other 
required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of the rule in the Federal Register. This rule is not a 
``major rule'' as defined by 5 U.S.C. 804(2).

List of Subjects in 40 CFR Part 180

    Environmental protection, Administrative practice and procedure, 
Agricultural commodities, Pesticides and pests, Reporting and 
recordkeeping requirements.

    Dated: December 21, 1998.

James Jones,
Director, Registration Division, Office of Pesticide Programs.
    Therefore, 40 CFR chapter I is amended as follows:

PART 180 -- [AMENDED]

    1. The authority citation for part 180 continues to read as 
follows:

    Authority: 21 U.S.C. 346a and 371.


    2. In Sec. 180.474, in paragraph (a), by designating the text after 
the heading as paragraph (a)(1) and alphabetically adding the following 
commodities to the table and by adding a new paragraph (a)(2) to read 
as follows:


Sec. 180.474  Tebuconazole; tolerances for residues.

    (a)(1) * * *


------------------------------------------------------------------------
                 Commodity                        Parts per million
------------------------------------------------------------------------
                          *    *    *    *    *

Grapes....................................  5.0

Grass, forage.............................  8.0

Grass, hay................................  25.0

Grass, seed screenings....................  55.0

Grass, straw..............................  30.0

                          *    *    *    *    *
------------------------------------------------------------------------

    (a)(2) Tolerances are established for the combined residues of the 
fungicide, tebuconazole and its 1-(4-chlorophenyl)-4,4-dimethyl-3-(1H-
1,2,4-triazole-1-yl-methyl)-pentane-3,5-diol metabolite.


------------------------------------------------------------------------
                 Commodity                        Parts per million
------------------------------------------------------------------------
Cattle, mbyp..............................  0.2

Goats, mbyp...............................  0.2

Horses, mbyp..............................  0.2

Milk......................................  0.1

Sheep, mbyp...............................  0.2
------------------------------------------------------------------------

* * * * *
[FR Doc. 99-319 Filed 1-7-99; 8:45 am]
BILLING CODE 6560-50-F
Tebuconazole; Pesticide Tolerance

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