[Federal Register Volume 62, Number 119 (Friday, June 20, 1997)]
[Rules and Regulations]
[Pages 33550-33557]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-16216]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-300506; FRL-5725-7]
RIN 2070-AB78


Tebuconazole; Pesticide Tolerance for Emergency Exemption

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes time-limited tolerances for 
residues of the fungicide tebuconazole in or on barley grain, barley 
hay, barley straw, wheat hay, wheat straw, pistachios, milk, and meat 
byproducts of cattle, goats, hogs, horses, poultry and sheep in 
connection with EPA's granting of emergency exemptions under section 18 
of the Federal Insecticide, Fungicide, and Rodenticide Act. These 
tolerances will expire and are revoked on June 30, 1998.
DATES: This regulation becomes effective June 20, 1997. Objections and 
requests for hearings must be received by EPA on or before August 19, 
1997.

ADDRESSES: Written objections and hearing requests, identified by the 
docket control number, [OPP-300506], 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-300506], must be submitted to: Public Information 
and Records Integrity Branch, Information Resources and Services 
Division (7506C), 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. 1132, CM #2, 
1921 Jefferson Davis Hwy., Arlington, VA.
    A copy of objections and hearing requests filed with the Hearing 
Clerk

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may also be submitted electronically by sending electronic mail (e-
mail) to: [email protected]. 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 file format 
or ASCII file format. All copies of objections and hearing requests in 
electronic form must be identified by the docket control number [OPP-
300506]. 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: Stephen Schaible, 
Registration Division (7505W), Office of Pesticide Programs, 
Environmental Protection Agency, 401 M St., SW., Washington, DC 20460. 
Office location, telephone number, and e-mail: Second Floor, Crystal 
Mall #2, Rm. 267, 1921 Jefferson Davis Highway, Arlington, VA 22202. 
(703) 308-9362, e-mail: [email protected].

SUPPLEMENTARY INFORMATION: EPA, on its own initiative, pursuant to 
section 408(e) and (l)(6) of the Federal Food, Drug, and Cosmetic Act 
(FFDCA), 21 U.S.C. 346a(e) and (l)(6), is establishing tolerances for 
the residues of the fungicide tebuconazole (alpha-[2-(4-chlorophenyl)-
ethyl]-alpha-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol) in or on 
barley grain at 2.0 parts per million (ppm), barley hay at 20 ppm, 
barley straw at 20 ppm, wheat hay at 15 ppm, wheat straw at 2.0 ppm, 
and pistachios at 1.0 ppm; the currently established tolerance of 0.05 
ppm for wheat grain is adequate to cover any residues in wheat grain 
expected from these section 18 uses. EPA is 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 
(HGW 2061), hereafter referred to in this document as tebuconazole, in 
milk at 0.1 ppm and in meat byproducts of cattle, goats, hogs, horses, 
poultry and sheep at 0.2 ppm. These tolerances will expire and are 
revoked on June 30, 1998. After June 30, 1998, EPA will publish a 
document in the Federal Register to remove the revoked tolerance from 
the Code of Federal Regulations.

I. Background and Statutory Authority

    The Food Quality Protection Act of 1996 (FQPA) (Pub. L. 104-170) 
was signed into law August 3, 1996. FQPA amends both the FFDCA, 21 
U.S.C. 301 et seq., and the Federal Insecticide, Fungicide, and 
Rodenticide Act (FIFRA), 7 U.S.C. 136 et seq. Among other things, FQPA 
amends FFDCA to bring all EPA pesticide tolerance-setting activities 
under section 408 with a new safety standard and new procedures. These 
activities are described below and discussed in greater detail in the 
final rule establishing the time-limited tolerance associated with the 
emergency exemption for use of propiconazole on sorghum (61 CFR 58135, 
November 13, 1996) (FRL-5572-9).
    New section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a 
tolerance (the legal limit for a pesticide chemical residue in or on a 
food) only if EPA determines that the tolerance is ``safe.'' Section 
408(b)(2)(A)(ii) defines ``safe'' to mean that ``there is a reasonable 
certainty that no harm will result from aggregate exposure to the 
pesticide chemical residue, including all anticipated dietary exposures 
and all other exposures for which there is reliable information.'' This 
includes exposure through drinking water and in residential settings, 
but does not include occupational exposure. Section 408(b)(2)(C) 
requires EPA to give special consideration to exposure of infants and 
children to the pesticide chemical residue in establishing a tolerance 
and to ``ensure that there is a reasonable certainty that no harm will 
result to infants and children from aggregate exposure to the pesticide 
chemical residue * * *.''
    Section 18 of FIFRA authorizes EPA to exempt any Federal or State 
agency from any provision of FIFRA, if EPA determines that ``emergency 
conditions exist which require such exemption.'' This provision was not 
amended by FQPA. EPA has established regulations governing such 
emergency exemptions in 40 CFR part 166. Section 408(l)(6) of the FFDCA 
requires EPA to establish a time-limited tolerance or exemption from 
the requirement for a tolerance for pesticide chemical residues in food 
that will result from the use of a pesticide under an emergency 
exemption granted by EPA under section 18 of FIFRA. Such tolerances can 
be established without providing notice or period for public comment.
    Because decisions on section 18-related tolerances must proceed 
before EPA reaches closure on several policy issues relating to 
interpretation and implementation of the FQPA, EPA does not intend for 
its actions on such tolerance to set binding precedents for the 
application of section 408 and the new safety standard to other 
tolerances and exemptions.

II. Emergency Exemptions for Tebuconazole on Barley, Pistachios, 
and Wheat and FFDCA Tolerances

    On April 16, 1997, the Louisiana Department of Agriculture and 
Forestry availed of itself the authority to declare the existence of a 
crisis situation within its state, thereby authorizing use under FIFRA 
section 18 of tebuconazole on wheat to control rust. On April 21 and 
April 25, the Mississippi Department of Agriculture and Commerce and 
the Arkansas State Plant Board, respectively, followed suit by 
declaring crisis situations within their states for the same pest. 
Unusually wet and cool weather this year are to blame for this disease 
outbreak. Triadimefon is registered for use on wheat, but existing 
stocks have been depleted; other registered alternatives, including 
tebuconazole, do not allow application at a sufficiently late stage to 
control rust. These emergency exemptions allow application later in the 
growth stage of wheat than is currently specified on the existing 
label. The Washington Department of Agriculture has requested a 
specific exemption for the use of tebuconazole on wheat to control 
stripe rust; a similar situation exists in which application of 
registered alternatives is not allowed at the later growth stages 
needed to control the disease. The Oregon, Washington and Idaho 
Departments of Agriculture have requested specific exemptions for the 
use of tebuconazole on barley to control rust, and North Dakota and 
Minnesota have requested use of this chemical on this crop to control 
head blight. The California Environmental Protection Agency, Department 
of Pesticide Regulation, has requested a specific exemption for the use 
of tebuconazole on pistachios to control late blight. After having 
reviewed these submissions, EPA concurs that emergency conditions exist 
for these states.
    As part of its assessment of these emergency exemptions, EPA 
assessed the potential risks presented by residues of tebuconazole in 
or on wheat, barley, and pistachios, as well as potential risks 
presented by secondary residues in milk and meat byproducts of cattle, 
goats, hogs, horses, poultry and sheep. In doing so, EPA considered the 
new safety standard in FFDCA section 408(b)(2), and EPA decided that 
the necessary tolerances under FFDCA section 408(l)(6) would be 
consistent with the new safety standard and with FIFRA section 18. 
These tolerances will permit the marketing of these commodities treated 
in accordance with the provisions of the section 18 emergency 
exemptions. Consistent with the need to

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move quickly on these emergency exemptions in order to address urgent 
non-routine situations and to ensure that the resulting food is safe 
and lawful, EPA is issuing these tolerances without notice and 
opportunity for public comment under section 408(e), as provided in 
section 408(l)(6). Although these tolerances will expire and are 
revoked on June 30, 1998, under FFDCA section 408(l)(5), residues of 
the pesticide not in excess of the amounts specified in the tolerances 
remaining in or on these commodities after that date will not be 
unlawful, provided the pesticide is applied in a manner that is lawful 
under FIFRA. EPA will take action to revoke these tolerances earlier if 
any experience with, scientific data on, or other relevant information 
on this pesticide indicate that the residues are not safe.
    Because these tolerances are being approved under emergency 
conditions, EPA has not made any decisions about whether tebuconazole 
meets EPA's registration requirements for use on barley, wheat, or 
pistachios or whether permanent tolerances for these uses would be 
appropriate. Under these circumstances, EPA does not believe that these 
tolerances serve as a basis for registration of tebuconazole by a State 
for special local needs under FIFRA section 24(c). Nor do these 
tolerances serve as the basis for any States other than those listed 
above to use this pesticide on these crops under section 18 of FIFRA 
without following all provisions of section 18 as identified in 40 CFR 
part 166. For additional information regarding these emergency 
exemptions for tebuconazole, contact the Agency's Registration Division 
at the address provided above.

III. Risk Assessment and Statutory Findings

    EPA performs a number of analyses to determine the risks from 
aggregate exposure to pesticide residues. First, EPA determines the 
toxicity of pesticides based primarily on toxicological studies using 
laboratory animals. These studies address many adverse health effects, 
including (but not limited to) reproductive effects, developmental 
toxicity, toxicity to the nervous system, and carcinogenicity. Second, 
EPA examines exposure to the pesticide through the diet (e.g., food and 
drinking water) and through exposures that occur as a result of 
pesticide use in residential settings.

A. Toxicity

    1. Threshold and non-threshold Effects. For many animal studies, a 
dose response relationship can be determined, which provides a dose 
that causes adverse effects (threshold effects) and doses causing no 
observed effects (the ``no-observed effect level'' or ``NOEL'').
    Once a study has been evaluated and the observed effects have been 
determined to be threshold effects, EPA generally divides the NOEL from 
the study with the lowest NOEL by an uncertainty factor (usually 100 or 
more) to determine the Reference Dose (RfD). The RfD is a level at or 
below which daily aggregate exposure over a lifetime will not pose 
appreciable risks to human health. An uncertainty factor (sometimes 
called a ``safety factor'') of 100 is commonly used since it is assumed 
that people may be up to 10 times more sensitive to pesticides than the 
test animals, and that one person or subgroup of the population (such 
as infants and children) could be up to 10 times more sensitive to a 
pesticide than another. In addition, EPA assesses the potential risks 
to infants and children based on the weight of the evidence of the 
toxicology studies and determines whether an additional uncertainty 
factor is warranted. Thus, an aggregate daily exposure to a pesticide 
residue at or below the RfD (expressed as 100 percent or less of the 
RfD) is generally considered acceptable by EPA. EPA generally uses the 
RfD to evaluate the chronic risks posed by pesticide exposure. For 
shorter term risks, EPA calculates a margin of exposure (MOE) by 
dividing the estimated human exposure into the NOEL from the 
appropriate animal study. Commonly, EPA finds MOEs lower than 100 to be 
unacceptable. This hundredfold margin of exposure is based on the same 
rationale as the hundredfold uncertainty factor.
    Lifetime feeding studies in two species of laboratory animals are 
conducted to screen pesticides for cancer effects. When evidence of 
increased cancer is noted in these studies, the Agency conducts a 
weight of the evidence review of all relevant toxicological data 
including short term and mutagenicity studies and structure activity 
relationship. Once a pesticide has been classified as a potential human 
carcinogen, different types of risk assessments (e.g., linear low dose 
extrapolations or margin of exposure calculation based on the 
appropriate NOEL) will be carried out based on the nature of the 
carcinogenic response and the Agency's knowledge of its mode of action.
    2. Differences in toxic effect due to exposure duration. The 
toxicological effects of a pesticide can vary with different exposure 
durations. EPA considers the entire toxicity data base, and based on 
the effects seen for different durations and routes of exposure, 
determines which risk assessments should be done to assure that the 
public is adequately protected from any pesticide exposure scenario. 
Both short and long durations of exposure are always considered. 
Typically, risk assessments include ``acute'', ``short-term'', 
``intermediate term'', and ``chronic''. These assessments are defined 
by the Agency as follows.
    Acute risk, by the Agency's definition, results from 1-day 
consumption of food and water, and reflects toxicity which could be 
expressed following a single oral exposure to the pesticide residues. 
High end exposure to food and water residues are typically assumed.
    Short-term risk results from exposure to the pesticide for a period 
of 1 to 7 days, and therefore overlaps with the acute risk assessment. 
Historically, this risk assessment was intended to address primarily 
dermal and inhalation exposure which could result, for example, from 
residential pesticide applications. However, since enaction of FQPA, 
this assessment has been expanded to include both dietary and non-
dietary sources of exposure, and will typically consider exposure from 
food, water, and residential uses when reliable data are available. In 
this assessment, risks from average food and water exposure, and high-
end residential exposure, are aggregated. High-end exposures from all 
three sources are not typically added because of the very low 
probability of this occurring in most cases, and because the other 
conservative assumptions built into the assessment assure adequate 
protection of public health. However, for cases in which high-end 
exposure can reasonably be expected from multiple sources (e.g. 
frequent and widespread homeowner use in a specific geographical area), 
multiple high-end risks will be aggregated and presented as part of the 
comprehensive risk assessment/characterization. Since the toxicological 
endpoint considered in this assessment reflects exposure over a period 
of at least 7 days, an additional degree of conservatism is built into 
the assessment; i.e., the risk assessment nominally covers 1 to 7 days 
exposure, and the toxicological endpoint/NOEL is selected to be 
adequate for at least 7 days of exposure. (Toxicity results at lower 
levels when the dosing duration is increased.)
    Intermediate-term risk results from exposure for 7 days to several 
months. This assessment is handled in a manner

[[Page 33553]]

similar to the short-term risk assessment.
    Chronic risk assessment describes risk which could result from 
several months to a lifetime of exposure. For this assessment, risks 
are aggregated considering average exposure from all sources for 
representative population subgroups including infants and children.

B. Aggregate Exposure

    In examining aggregate exposure, FFDCA section 408 requires that 
EPA take into account available and reliable information concerning 
exposure from the pesticide residue in the food in question, residues 
in other foods for which there are tolerances, residues in groundwater 
or surface water that is consumed as drinking water, and other non-
occupational exposures through pesticide use in gardens, lawns, or 
buildings (residential and other indoor uses). Dietary exposure to 
residues of a pesticide in a food commodity are estimated by 
multiplying the average daily consumption of the food forms of that 
commodity by the tolerance level or the anticipated pesticide residue 
level. The Theoretical Maximum Residue Contribution (TMRC) is an 
estimate of the level of residues consumed daily if each food item 
contained pesticide residues equal to the tolerance. In evaluating food 
exposures, EPA takes into account varying consumption patterns of major 
identifiable subgroups of consumers, including infants and children. 
The TMRC is a ``worst case'' estimate since it is based on the 
assumptions that food contains pesticide residues at the tolerance 
level and that 100 percent of the crop is treated by pesticides that 
have established tolerances. If the TMRC exceeds the RfD or poses a 
lifetime cancer risk that is greater than approximately one in a 
million, EPA attempts to derive a more accurate exposure estimate for 
the pesticide by evaluating additional types of information 
(anticipated residue data and/or percent of crop treated data) which 
show, generally, that pesticide residues in most foods when they are 
eaten are well below established tolerances.
    Percent of crop treated estimates are derived from Federal and 
private market survey data. Typically, a range of estimates are 
supplied and the upper end of this range is assumed for the exposure 
assessment. By using this upper end estimate of percent of crop 
treated, the Agency is reasonably certain that exposure is not 
understated for any significant subpopulation group. Further, regional 
consumption information is taken into account through EPA's computer-
based model for evaluating the exposure of significant subpopulations 
including several regional groups, to pesticide residues. For this 
pesticide, the most highly exposed population subgroup (non-nursing 
infants < 1 year old) was not regionally based.

IV. 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 
these actions. Tebuconazole is already registered by EPA for numerous 
food uses. For the purpose of these emergency exemptions, EPA has 
sufficient data to assess the hazards of tebuconazole and to make a 
determination on aggregate exposure, consistent with 408(b)(2), for 
time-limited tolerances for residues of tebuconazole on barley grain at 
2.0 ppm, barley hay at 20 ppm, barley straw at 20 ppm, wheat hay at 15 
ppm, wheat straw at 2.0 ppm, pistachios at 1.0 ppm, milk at 0.1 ppm, 
and meat byproducts of cattle, goats, hogs, horses, poultry and sheep 
at 0.2 ppm. EPA's assessment of the dietary exposures and risks 
associated with establishing these tolerances follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its 
validity, completeness, and reliability as well as the relationship of 
the results of the studies to human risk. EPA has also considered 
available information concerning the variability of the sensitivities 
of major identifiable subgroups of consumers, including infants and 
children. The nature of the toxic effects caused by tebuconazole are 
discussed below.
    1. Acute toxicity. For acute dietary risk assessment, OPP 
recommended use of the developmental NOEL of 10 mg/kg/day from the 
developmental toxicity study in mice. Effects observed at the lowest 
observed effect level (LOEL) of 30 mg/kg/day are an increased number of 
runts and fetuses with malformations of the skull, brain, and spinal 
cord. The population subgroup of concern for this acute dietary risk 
assessment is females (13+ years).
    2. Short- and intermediate-term toxicity. OPP has determined that 
short- and intermediate-term inhalation risk assessments and short-term 
dermal risk assessments are appropriate for non-occupational, non-
dietary routes of exposure. OPP recommends that the NOEL of 1,000 mg/
kg/day, taken from the dermal developmental toxicity study in mice, be 
used for the short-term dermal MOE calculations. This NOEL was the 
highest dose tested in the study. For short- and intermediate-term 
inhalation MOE calculations, OPP recommends using the NOEL of 0.0106 
mg/L/day (1.75 mg/kg/day), based on liver toxicity and piloerection at 
the LOEL of 0.1558 mg/L/day (25.7 mg/kg/day) in the 3-week inhalation 
rat toxicity study.
    3. Chronic toxicity. The RfD of 0.03 mg/kg/day was established 
based on the NOEL of 2.96 mg/kg/day from a 1-year dog feeding study. 
Adrenal effects (fatty change and hypertrophy) were observed at the 
LOEL of 4.39 mg/kg/day. An Uncertainty Factor (UP) of 100 was applied 
to account for both interspecies and intraspecies variability.
    4. Carcinogenicity. OPP's Cancer Peer Review Committee (CPRC) has 
determined that tebuconazole is a Group C (possible human carcinogen) 
chemical, based on mouse liver tumors in both sexes (adenomas and 
carcinomas in males and carcinomas in females) at 280 mg/kg/day, the 
highest dose tested. OPP recommends using the RfD approach for 
quantification of human risk. Therefore, the RfD is deemed protective 
of all chronic human health effects, including cancer.

B. Aggregate Exposure

    Tolerances have been established (40 CFR 180.474) for parent 
tebuconazole (alpha-[2-(4-chlorophenyl)-ethyl]-alpha-(1,1-
dimethylethyl)-1H-1,2,4-triazole-1-ethanol), in or on a variety of raw 
agricultural commodities at levels ranging from 0.05 ppm in barley, oat 
and wheat grain to 4.0 ppm in cherries and peanut hulls. Time-limited 
tolerances for wheat commodities are based on residue data provided 
with the section 18 submission; time-limited tolerances for barley 
commodities are based on residue data submitted with tolerance petition 
PP#9F3724; and the time-limited tolerance for pistachios is based on 
residue data submitted with tolerance petition PP#3F4222. Time-limited 
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 (HGW 2061) will be established to address potential 
secondary residues of tebuconazole in milk and meat byproducts of 
cattle, goats, hogs, horses, poultry and sheep.
    For the purpose of assessing potential chronic dietary exposure 
from tebuconazole, EPA assumed tolerance level residues and 100% of 
crop treated to estimate the Theoretical Maximum Residue Contribution 
(TMRC) for major identifiable subgroups of consumers,

[[Page 33554]]

including infants and children, from the proposed and existing food 
uses of tebuconazole. These same assumptions were made in assessing 
acute dietary exposure as well.
    In examining aggregate exposure, FQPA directs EPA to consider 
available information concerning exposures from the pesticide residue 
in food and all other non-occupational exposures. The primary non-food 
sources of exposure the Agency looks at include drinking water (whether 
from groundwater or surface water), and exposure through pesticide use 
in gardens, lawns, or buildings (residential and other indoor uses).
    There are no groundwater data for tebuconazole available in OPP's 
One-Liner Data Base. No Maximum Concentration Level and no Health 
Advisory Level has been established for residues of tebuconazole in 
drinking water.
    Because the Agency lacks sufficient water-related exposure data to 
complete a comprehensive drinking water risk assessment for many 
pesticides, EPA has commenced and nearly completed a process to 
identify a reasonable yet conservative bounding figure for the 
potential contribution of water related exposure to the aggregate risk 
posed by a pesticide. In developing the bounding figure, EPA estimated 
residue levels in water for a number of specific pesticides using 
various data sources. The Agency then applied the estimated residue 
levels, in conjunction with appropriate toxicological endpoints (RfD's 
or acute dietary NOEL's) and assumptions about body weight and 
consumption, to calculate, for each pesticide, the increment of 
aggregate risk contributed by consumption of contaminated water. While 
EPA has not yet pinpointed the appropriate bounding figure for exposure 
from contaminated water, the ranges the Agency is continuing to examine 
are all below the level that would cause exposure from tebuconazole to 
exceed the RfD if the tolerance being considered in this document were 
granted. The Agency has therefore concluded that the potential 
exposures associated with tebuconazole in water, even at the higher 
levels the Agency is considering as a conservative upper bound, would 
not prevent the Agency from determining that there is a reasonable 
certainty of no harm if the tolerance is granted.
    Tebuconazole is not currently registered for indoor or outdoor 
residential use. Thus, no non-dietary, non-occupational exposure is 
expected.

C. Cumulative Exposure to Substances With Common Mechanism of Toxicity

    Tebuconazole is a member of the triazole class of systemic 
fungicides (The Pesticide Book, 4th ed., 1994). Other triazoles include 
bitertanol, cyproconazole, diclobutrazole, difenoconazole, 
diniconazole, fenbuconazole, flusilazole, hexaconazole, myclobutanil, 
penconazole, propiconazole, tetraconazole, triadimefon, and 
triadimenol.
    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.'' The Agency believes that ``available 
information'' in this context might include not only toxicity, 
chemistry, and exposure data, but also scientific policies and 
methodologies for understanding common mechanisms of toxicity and 
conducting cumulative risk assessments. For most pesticides, although 
the Agency has some information in its files that may turn out to be 
helpful in eventually determining whether a pesticide shares a common 
mechanism of toxicity with any other substances, EPA does not at this 
time have the methodologies to resolve the complex scientific issues 
concerning common mechanism of toxicity in a meaningful way. EPA has 
begun a pilot process to study this issue further through the 
examination of particular classes of pesticides. The Agency hopes that 
the results of this pilot process will increase the Agency's scientific 
understanding of this question such that EPA will be able to develop 
and apply scientific principles for better determining which chemicals 
have a common mechanism of toxicity and evaluating the cumulative 
effects of such chemicals. The Agency anticipates, however, that even 
as its understanding of the science of common mechanisms increases, 
decisions on specific classes of chemicals will be heavily dependent on 
chemical specific data, much of which may not be presently available.
    Although at present the Agency does not know how to apply the 
information in its files concerning common mechanism issues to most 
risk assessments, there are pesticides as to which the common mechanism 
issues can be resolved. These pesticides include pesticides that are 
toxicologically dissimilar to existing chemical substances (in which 
case the Agency can conclude that it is unlikely that a pesticide 
shares a common mechanism of activity with other substances) and 
pesticides that produce a common toxic metabolite (in which case common 
mechanism of activity will be assumed).
    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.

D. Aggregate Risks and Determination of Safety for U.S. Population

    1. Acute risk. EPA has concluded that for the population subgroup 
of concern, females (13+ years), acute aggregate exposure to 
tebuconazole from existing and proposed food uses will result in an MOE 
of 1,000. Despite the potential for exposure to tebuconazole in 
drinking water, EPA does not expect the aggregate exposure to exceed 
the level of concern for acute dietary exposure. EPA concludes that 
there is a reasonable certainty that no harm will result from aggregate 
exposure to tebuconazole residues.
    2. Chronic risk. EPA has concluded that aggregate exposure to 
tebuconazole from food will utilize 6% of the RfD for the U.S. 
population. The major identifiable subgroup with the highest aggregate 
exposure is non-nursing infants less than 1 year old (discussed below). 
EPA generally has no concern for exposures below 100 percent 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, EPA does not expect the aggregate exposure to exceed 
100% of the RfD. 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

    In assessing the potential for additional sensitivity of infants 
and children to residues of tebuconazole, EPA considered data from 
developmental toxicity studies in the rat, rabbit, and mouse and a 2-

[[Page 33555]]

 generation reproduction study in the rat. The developmental toxicity 
studies are designed to evaluate adverse effects on the developing 
organism resulting from pesticide exposure during prenatal development 
to one or both parents. Reproduction studies provide information 
relating to effects from exposure to the pesticide on the reproductive 
capability of mating animals and data on systemic toxicity.
    The pre- and post-natal toxicology data base for tebuconazole is 
complete with respect to current toxicological data requirements. The 
data base does not indicate a potential for increased sensitivity from 
pre- and post-natal exposure.
    From the rat developmental study, the maternal NOEL was 30 mg/kg/
day, based on increased liver weight at the LOEL of 60 mg/kg/day. The 
developmental NOEL was 30 mg/kg/day, based on delayed ossification and 
supernumerary ribs at the developmental LOEL of 60 mg/kg/day. In the 
rabbit developmental study, the maternal NOEL was 30 mg/kg/day, based 
on decreased weight gain and food consumption at the maternal LOEL of 
100 mg/kg/day. The developmental NOEL was 30 mg/kg/day, based on 
increased resorptions due to post-implantation loss at the 
developmental LOEL of 100 mg/kg/day. The maternal NOEL in the mouse 
study was 10 mg/kg/day, with reduced hematocrit occurring at the 
maternal LOEL of 30 mg/kg/day in the oral developmental toxicity study. 
The developmental NOEL was 10 mg/kg/day, with effects at the LOEL of 30 
mg/kg/day being an increased number of runts, and fetuses with 
malformations of the skull, brain and spinal cord.
    In the 2-generation rat reproduction study, the parental NOEL was 
15 mg/kg/day, based on decreased body weight and increased spleen 
weight at the LOEL of 50 mg/kg/day. The reproductive NOEL was 15 mg/kg/
day, with decreased body weight of neonates being the effect at the 
LOEL of 50 mg/kg/day.
    FDCA section 408 provides that EPA shall apply an additional 
tenfold margin of safety for infants and children in the case of 
threshold effects to account for pre-and post-natal toxicity and the 
completeness of the database unless EPA determines that a different 
margin of safety will be safe for infants and children. Margins of 
safety are incorporated into EPA risk assessments either directly 
through use of a margin of exposure analysis or through using 
uncertainty (safety) factors in calculating a dose level that poses no 
appreciable risk to humans. EPA believes that reliable data support 
using the standard margin of exposure and uncertainty factor (usually 
100 for combined inter- and intra-species variability)) and not the 
additional tenfold margin of exposure/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 margin of exposure/safety factor.
    Neither the rat, rabbit, and mouse developmental studies nor the 
rat reproduction study seem to demonstrate any special pre- or post-
natal sensitivity for infants and children, since the NOELs and LOELs 
were the same for both parental and pup toxicity in all of these 
studies. This demonstrates that developmental or reproductive toxicity 
to pups occurs only in the presence of maternal effects. EPA therefore 
concludes that reliable data support use of the standard hundredfold 
uncertainty factor and that an additional safety factor is not needed 
to protect infants and children.
    1. Acute risk. The acute dietary MOE for females (13+ years), the 
subpopulation of concern for developmental toxicity, is 1,000. 
Generally, MOEs of greater than 100 are of no concern to the Agency. 
Despite the potential for exposure to tebuconazole in drinking water, 
EPA does not expect the aggregate exposure to infants or children to 
exceed the level of concern for acute dietary exposure. EPA concludes 
that there is a reasonable certainty that no harm will result to 
infants and children from aggregate exposure to tebuconazole residues.
    2. Chronic risk. Using the conservative exposure assumptions 
described above, EPA has concluded that aggregate exposure to 
tebuconazole from food will utilize 32% of the RfD for non-nursing 
infants and 14% of the RfD for children 1 through 6 years old. EPA 
generally has no concern for exposures below 100 percent 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, EPA does not expect the aggregate exposure to exceed 
100% of the RfD. EPA concludes that there is a reasonable certainty 
that no harm will result to infants and children from chronic aggregate 
exposure to tebuconazole residues.

V. Other Considerations

    The nature of tebuconazole residues in plants and animals is 
adequately understood. The residue of concern in plants is tebuconazole 
per se. In ruminants and poultry, the residue of concern is the parent 
compound and its 1-(4-chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4-triazole-
1-yl-methyl)-pentane-3,5-diol metabolite (HGW 2061). Adequate 
enforcement methodology is available to enforce the tolerance 
expressions. For the pistachio, barley and wheat tolerances, a gas 
chromatographic method is available with the Agency, associated with 
PP#9F3724; for the meat byproduct and milk tolerances, a gas 
chromatographic method for determining residues of tebuconazole and its 
metabolite HGW 2061 is available with the Agency, also associated with 
PP#9F3724. Residues of tebuconazole per se are not expected to exceed 
2.0 ppm in/on barley grain, 20 ppm in/on barley hay, 20 ppm in/on 
barley straw, 15 ppm in/on wheat hay, 2.0 ppm in/on wheat straw, and 
1.0 ppm in/on pistachios as a result of these section 18 uses. Combined 
residues of tebuconazole and its metabolite HGW 2061 are not expected 
to exceed 0.1 ppm in/on milk, and 0.2 ppm in/on meat byproducts of 
cattle, goats, hogs, horses, poultry and sheep as a result of these 
section 18 uses.
    Codex maximum residue limits (MRLs) exist for residues of 
tebuconazole per se in/on barley grain at 0.2 ppm; barley straw and dry 
fodder at 10 ppm; wheat grain at 0.05 ppm; wheat straw and dry fodder 
at 10 ppm; milk (cattle) at 0.01 ppm; cattle edible offal at 0.05 ppm; 
and chicken edible offal at 0.05 ppm. These Codex MRLs are not in 
harmony with those of the United States with respect to: (a) the 
tolerance expression for animal commodities; (b) the definitions of the 
tolerated commodities; and, (c) the tolerance levels. These disparities 
can not be harmonized for purposes of these section 18 actions.
    OPP suggests that, once permanent tolerances and section 3 
registrations are established for the uses on barley and wheat, the 
registrant consider providing all relevant studies to Codex in order 
that Codex MRLs may be amended to accommodate U.S. use needs.
    There is no Canadian MRL established for use of tebuconazole on 
barley. There is a Mexican MRL of 0.2 ppm for residues of tebuconazole 
per se in/on barley (grain); the use pattern of these section 18s does 
not permit harmonization to that tolerance level.

[[Page 33556]]

    There is a Canadian MRL established for tebuconazole on ``wheat 
seed'' at 0.1 ppm. There is no Mexican MRL.
    There are no Codex, Canadian or Mexican MRLs for residues of 
tebuconazole in or on pistachios. International harmonization is not an 
issue for this section 18 use.

VI. Conclusion

    Therefore, tolerances in connection with the FIFRA section 18 
emergency exemptions are established for residues of tebuconazole in or 
on barley grain at 2.0 ppm, barley hay at 20 ppm, barley straw at 20 
ppm, wheat hay at 15 ppm, wheat straw at 2.0 ppm, and pistachios at 1.0 
ppm. 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 (HGW 2061) in milk at 
0.1 ppm and in meat byproducts of cattle, goats, hogs, horses, poultry 
and sheep at 0.2 ppm. These tolerances will expire and are revoked on 
June 30, 1998.

VII. 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 August 19, 1997, file written objections to any 
aspect of this regulation and may also request a hearing on those 
objections. Objections and hearing requests must be filed with the 
Hearing Clerk, at the address given above (40 CFR 178.20). A copy of 
the objections and/or hearing requests filed with the Hearing Clerk 
should be submitted to the OPP docket for this rulemaking. The 
objections submitted must specify the provisions of the regulation 
deemed objectionable and the grounds for the objections (40 CFR 
178.25). Each objection must be accompanied by the fee prescribed by 40 
CFR 180.33(i). If a hearing is requested, the objections must include a 
statement of the factual issues on which a hearing is requested, the 
requestor's contentions on such issues, and a summary of any evidence 
relied upon by the requestor (40 CFR 178.27). A request for a hearing 
will be granted if the Administrator determines that the material 
submitted shows the following: There is genuine and substantial issue 
of fact; there is a reasonable possibility that available evidence 
identified by the requestor would, if established, resolve one or more 
of such issues in favor of the requestor, taking into account 
uncontested claims or facts to the 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.

VIII. Public Docket

    The official record for this rulemaking, as well as the public 
version, has been established for this rulemaking under docket control 
number [OPP-300506] (including comments and data submitted 
electronically as described below). 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 official rulemaking record is located at the Virginia 
address in ADDRESSES at the beginning of this document.

    Electronic comments can be sent directly to EPA at:
    [email protected]

    Electronic comments must be submitted as an ASCII file avoiding the 
use of special characters and any form of encryption. Comment and data 
will also be accepted on disks in Wordperfect 5.1 file format or ASCII 
file format. All comments and data in electronic form must be 
identified by the docket control number [OPP-300506]. Electronic 
comments on this rule may be filed online at many Federal Depository 
Libraries.

IX. Regulatory Assessment Requirements

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this 
action is not a ``significant regulatory action'' and, since this 
action does not impose any information collection requirements as 
defined by the Paperwork Reduction Act, 44 U.S.C. 3501 et seq., it is 
not subject to review by the Office of Management and Budget. In 
addition, this action does not impose any enforceable duty or contain 
any unfunded mandate as described in the Unfunded Mandates Reform Act 
of 1995 (Pub. L. 104-4), or require prior consultation with State 
officials as specified by Executive Order 12875 (58 FR 58093, October 
28, 1993), or special considerations as required by Executive Order 
12898 (59 FR 7629, February 16, 1994).
    Because FFDCA section 408(l)(6) permits establishment of this 
regulation without a notice of proposed rulemaking, the regulatory 
flexibility analysis requirements of the Regulatory Flexibility Act, 5 
U.S.C. 604(a), do not apply. Nonetheless, the Agency has previously 
assessed whether establishing tolerances or exemptions from tolerance, 
raising tolerance levels, or expanding exemptions adversely impact 
small entities and concluded, as a generic matter, that there is no 
adverse impact. (46 FR 24950) (May 4, 1981).
    Under 5 U.S.C. 801(a)(1)(A) of the Small Business Regulatory 
Enforcement Fairness Act of 1996 (Title II of Pub. L. 104-121, 110 
Stat. 847), EPA submitted 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 General Accounting 
Office prior to publication of the rule in today's 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: June 9, 1997.

James Jones,

Acting Director, Registration Division, Office of Pesticide Programs.

    Therefore, 40 CFR Chapter I is amended as follows:

PART 180 [AMENDED]

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

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

    2. Section 180.474 is amended as follows:
    i. The section heading is revised to read as set forth below.

[[Page 33557]]

    ii. The existing text is designated as paragraph (a) ``General''.
    iii. Paragraphs (b), (c), and (d) are added as follows:


Sec. 180.474   Tebuconazole; tolerances for residues.

    (a) General. *  *  *
*    *    *    *    *
    (b) Section 18 emergency exemptions--(1) Use on grains, hay and 
other plant products. Time-limited tolerances are established for 
residues of the fungicide tebuconazole (alpha-[2-(4-chlorophenyl)-
ethyl]-alpha-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol) in 
connection with use of the pesticide under section 18 emergency 
exemptions granted by EPA. The tolerances will expire and are revoked 
on the dates specified in the following table.

------------------------------------------------------------------------
                                     Parts per    Expiration/Revocation 
             Commodity                million              Date         
------------------------------------------------------------------------
Barley, grain.....................      2.0           June 30, 1998     
Barley, hay.......................      20.0               Do.          
Barley, straw.....................      20.0               Do.          
Pistachios........................      1.0                Do.          
Wheat, hay........................      15.0               Do.          
Wheat, straw......................      2.0                Do.          
------------------------------------------------------------------------

    (2) Use on meat and meat byproducts. Time-limited 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 (HGW 2061) in connection with use of the 
pesticide under section 18 emergency exemptions granted by EPA. The 
tolerances will expire and are revoked on the dates specified in the 
following table.

------------------------------------------------------------------------
                                     Parts per    Expiration/Revocation 
             Commodity                million              Date         
------------------------------------------------------------------------
Milk..............................      0.1           June 30, 1998     
Cattle, meat byproducts...........      0.2                Do.          
Goats, meat byproducts............      0.2                Do.          
Hogs, meat byproducts.............      0.2                Do.          
Horses, meat byproducts...........      0.2                Do.          
Poultry, meat byproducts..........      0.2                Do.          
Sheep, meat byproducts............      0.2                Do.          
------------------------------------------------------------------------

    (c) Tolerances with regional registrations. [Reserved]
    (d) Indirect or inadvertent residues. [Reserved]

[FR Doc. 97-16216 Filed 6-19-97; 8:45 am]
BILLING CODE 6560-50-F