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Myclobutanil - Pesticide Tolerances for Emergency Exemptions 6/98

[Federal Register: July 10, 1998 (Volume 63, Number 132)]
[Rules and Regulations]
[Page 37289-37295]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr10jy98-14]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-300678; FRL-5798-6]
RIN 2070-AB78
Myclobutanil; Pesticide Tolerances for Emergency Exemptions
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes a time-limited tolerance for
combined residues of myclobutanil in or on caneberries, and in or on
dried hop cones. This action is in response to EPA's granting of an
emergency exemption under section 18 of the Federal Insecticide,
Fungicide, and Rodenticide Act authorizing use of the pesticide on
caneberries in Oregon, and use of the pesticide on hops in Idaho,
Oregon, and Washington. This regulation establishes a maximum
permissible level for residues of myclobutanil in these food
commodities pursuant to section 408(l)(6) of the Federal Food, Drug,
and Cosmetic Act, as amended by the Food Quality Protection Act of
1996. The tolerances will expire and be revoked on December 31, 1999.

DATES: This regulation is effective July 10, 1998. Objections and
requests for hearings must be received by EPA on or before September 8,
1998.

ADDRESSES: Written objections and hearing requests, identified by the
docket control number, [OPP-300678], 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-300678], 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, CM #2, 1921
Jefferson Davis Hwy., Arlington, VA.
    A copy of objections and hearing requests filed with the Hearing
Clerk may also be submitted electronically by sending electronic mail
(e-mail) to: opp-docket@epamail.epa.gov. Copies of objections and
hearing requests must be submitted as an ASCII file avoiding the use of
special characters and any form of encryption. Copies of objections and
hearing requests will also be accepted on disks in WordPerfect 5.1/6.1
file format or ASCII file format. All copies of objections and hearing
requests in electronic form must be identified by the docket control
number [OPP-300678]. 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: David Deegan, 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) 308-9358, e-mail:
deegan.dave@epamail.epa.gov.

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 a tolerance for
combined residues of the fungicide myclobutanil α-butyl-
α-(4-chlorophenyl)-1H-1,2,4-triazole-1-propanenitrile plus its
alcohol metabolite α-(3-hydroxybutyl)-α-(4-
chlorophenyl)-1H-1,2,4-triazole-1-propanenitrile (free and bound), in
or on caneberries at 1.0 part per million (ppm), and in or on dried hop
cones at 5.0 ppm. These tolerances will expire and be revoked on
December 31, 1999. EPA will publish a document in the Federal Register
to remove the revoked tolerance from the Code of Federal Regulations.

I. Background and Statutory Authority

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

[[Page 37290]]

II. Emergency Exemptions for Myclobutanil on Caneberries and Hops
and FFDCA Tolerances

    On March 25, 1998, EPA received a request from the state of Oregon
for an exemption, as allowed under provisions of FIFRA section 18, to
authorize the use of the fungicide myclobutanil [Rally 40W Fungicide,
manufactured by Rohm & Haas Company] to control orange rust on
caneberries (blackberries, Boysenberries, and black raspberries). The
basis of the claimed emergency situation is that orange rust is a new
pest for growers of caneberries in the Willamette Valley of Oregon, and
that without use of this chemical (in combination with other, non-
chemical control measures) this disease would be likely to become
widespread throughout the Willamette Valley and other agricultural
areas of Oregon and potentially neighboring states. Under FIFRA section
18 provisions, on May 22, 1998 EPA authorized the use of myclobutanil
on caneberries for control of orange rust in Oregon. EPA's
authorization allows up to five ground applications of the product at a
rate of 0.125 lbs. active ingredient (5 oz. product) on 730 acres. The
exemption expires on November 1, 1998.
     On January 9, 1998, EPA received a regional request from the
states of Idaho, Oregon, and Washington for an exemption, as allowed
under provisions of FIFRA section 18, to authorize the use of the
fungicide myclobutanil [Rally 40WSP, Manufactured by Rohm & Haas
Company] to control powdery mildew on hops. The emergency situation
described was that powdery mildew is a new pest for hops in the
applicant states, and the disease has very rapidly become established
and has not been controlled adequately by non-chemical measures, and
that there are no other products registered for use on hops to control
powdery mildew. On May 5, 1998 EPA authorized the use of myclobutanil
on hops for control of powdery mildew in Idaho, Oregon, and Washington.
EPA's authorization allows up to eight ground or aerial applications of
the product at a rate of 0.05 - 0.25 lbs. active ingredient (2 - 10 oz.
product) on 44,730 acres within the three states. These exemptions
expire on October 1, 1998.
    As part of its assessment of this emergency exemption, EPA assessed
the potential risks presented by residues of myclobutanil in or on
caneberries and in or on hops. In doing so, EPA considered the new
safety standard in FFDCA section 408(b)(2), and EPA decided that the
necessary tolerance under FFDCA section 408(l)(6) would be consistent
with the new safety standard and with FIFRA section 18. Consistent with
the need to move quickly on the emergency exemption in order to address
an urgent non-routine situation and to ensure that the resulting food
is safe and lawful, EPA is issuing this tolerance without notice and
opportunity for public comment under section 408(e), as provided in
section 408(l)(6). Although these tolerances will expire and be revoked
on December 31, 1999, under FFDCA section 408(l)(5), residues of the
pesticide not in excess of the amounts specified in the tolerance
remaining in or on caneberries or dried hop cones after that date will
not be unlawful, provided the pesticide is applied in a manner that was
lawful under FIFRA, and the residues do not exceed a level that was
authorized by this tolerance at the time of that application. EPA will
take action to revoke this tolerance earlier if any experience with,
scientific data on, or other relevant information on this pesticide
indicate that the residues are not safe.
    Because this tolerance is being approved under emergency conditions
EPA has not made any decisions about whether myclobutanil meets EPA's
registration requirements for use on caneberries or hops, or whether
permanent tolerances for these uses would be appropriate. Under these
circumstances, EPA does not believe that this tolerance serves as a
basis for registration of myclobutanil by a State for special local
needs under FIFRA section 24(c). Nor does this tolerance serve as the
basis for any State other than 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 the emergency exemption for
myclobutanil, 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 MOE 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 MOE calculation based on the appropriate NOEL) will
be carried out based on the nature of the

[[Page 37291]]

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" risks. 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 1-7 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 1-7 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 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% 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
this action, EPA has sufficient data to assess the hazards of
myclobutanil and to make a determination on aggregate exposure,
consistent with section 408(b)(2), for a time-limited tolerance for
combined residues of myclobutanil on caneberries at 1.0 ppm and for
combined residues of myclobutanil on dried hop cones at 5.0 ppm. EPA's
assessment of the dietary exposures and risks associated with
establishing the tolerance follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its
validity, completeness, and reliability as well as the relationship of
the results of the studies to human risk. EPA has also considered
available information concerning the variability of the sensitivities
of major identifiable subgroups of consumers, including infants and
children. The nature of the toxic effects caused by myclobutanil are
discussed below.
    1. Acute toxicity. None. For acute dietary risk assessment, EPA has
not recommended an acute dietary endpoint.
    2. Chronic toxicity. EPA has established the RfD for myclobutanil
at 0.025 milligrams/kilogram/day (mg/kg/day). This RfD is based on the
NOEL from the chronic feeding study in the rat (2.49 mg/kg/day) and a
safety factor of 100 (10 for intraspecies and 10 for interspecies). The
LOEL for the chronic rat feeding study is 9.84 mg/kg/day based on
decreased testicular weight and increased testicular atrophy. EPA's
assessment notes that the dose of 2.49 mg/kg/day established in the
above study is supported by the Parental Systemic Toxicity NOEL and
LOEL established in the Two-Generation reproduction study in rats. In
that study the NOEL was 2.5 mg/kg/day and the LOEL was 10 mg/kg/day.
EPA has determined that the 10X factor to

[[Page 37292]]

account for enhanced sensitivity of infants and children (as required
by FQPA) should be removed. A safety factor of 100 is adequate because
of the following:
    i. Developmental toxicity studies showed no increased sensitivity
in fetuses as compared to maternal animals following in utero exposures
in rats and rabbits.
    ii. A two generation reproduction toxicity study in rats showed no
increased sensitivity in pups that were compared to adults.
    iii. The toxicology data base is complete and there are no data
gaps.
    3. Carcinogenicity. Myclobutanil is classified as Category E: not
carcinogenic in two acceptable animal studies. Q1* is not
applicable.

B. Exposures and Risks

    1. From food and feed uses. Tolerances have been established (40
CFR 180.443) for the combined residues of myclobutanil, in or on a
variety of raw agricultural commodities. Tolerances have been
established for the residues of myclobutanil α-butyl-α-
(4-chlorophenyl)-1H-1,2,4-triazole-1-propanenitrile and its metabolite
α-(3-hydroxybutyl)-α-(4-chlorophenyl)-1H-1,2,4-
triazole-1-propanenitrile (free and bound), expressed as myclobutanil,
in or on a variety of raw agricultural commodities and processed
commodities at levels ranging from 0.02 ppm in cottonseed to 25.0 ppm
in raisin waste. Meat, milk, poultry and egg tolerances have been
established at levels ranging from 0.02 ppm to 1.0 ppm. Risk
assessments were conducted by EPA to assess dietary exposures and risks
from myclobutanil as follows:
    i.  Acute exposure and risk. If applicable. 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. In performing its
assessment of the risks from residues of myclobutanil, EPA has not
recommended an acute dietary toxicological endpoint, so an acute
dietary risk assessment is not required.
    ii. Chronic exposure and risk. In conducting this chronic dietary
(food only) risk assessment, EPA has made somewhat conservative
assumptions. This results in an overestimate of human dietary exposure.
Percent crop-treated estimates were utilized for selected commodities
included in the assessment. Thus, in making a safety determination for
this tolerance, EPA is taking into account this partially refined
exposure assessment.
    The existing myclobutanil tolerances (published, pending, and
including the necessary section 18 tolerances) result in an Anticipated
Residue Contribution (ARC) that is equivalent to the following
percentages of the RfD, ranging from 17% (U.S. population, 48 states)
to 75% (non-nursing infants, < 1 year old).
    2. From drinking water--chronic exposure and risk. Based on
information available to EPA, myclobutanil is persistent and not
considered mobile in soils with the exception of sandy soils. Data are
not available for its metabolite alpha-(3-hydroxybutyl)-alpha-(4-
chlorophenyl)-1H-1,2,4-triazole-1-propanenitrile. There is no
established Maximum Contaminant Level for residues of myclobutanil in
drinking water. No Health Advisory Levels for myclobutanil in drinking
water have been established. The "Pesticides in Groundwater Database"
(EPA 734-12-92-001, September 1992) has no information concerning
myclobutanil.
    EPA has estimated ground and surface water concentrations for
myclobutanil based on the label rate of 0.65 lbs a.i./acre and assuming
15 applications per season. (These numbers were based on turf uses.)
    Surface water EEC: Acute = 145.96 ppb (0.14596 ppm or milligrams/
liter (mg/l))(maximum initial concentration)
    Chronic = 118.6 ppb (0.1186 ppm or mg/l)(average 56-day
concentration)
    Ground water EEC: 3.6 ppb (0.0036 ppm or mg/l) (use for both acute
and chronic)
    EPA has calculated drinking water levels of concern (DWLOCs) for
chronic (non-cancer) exposure to be 0.7 ppm for U.S. population, 0.6
ppm for Hispanics, and 0.06 ppm for non-nursing infants (< 1 year old).
    The estimated average concentration of myclobutanil in surface
water is 0.04 ppm. Chronic concentrations in ground water are not
expected to be higher than the acute concentrations. The estimated
average concentrations of myclobutanil in surface water are less than
EPA's levels of concern for myclobutanil in drinking water as a
contribution to chronic aggregate exposure. Therefore, taking into
account the present uses and uses proposed in this action, EPA
concludes with reasonable certainty that residues of myclobutanil in
drinking water (when considered along with other sources of exposure
for which EPA has reliable data) would not result in unacceptable
levels of aggregate human health risk at this time.
    EPA bases this determination on a comparison of estimated
concentrations of myclobutanil in surface waters and ground waters to
back-calculated "levels of concern" for myclobutanil in drinking
water. These levels of concern in drinking water were determined after
EPA has considered all other non-occupational human exposures for which
it has reliable data, including all current uses, and uses considered
in this action. The estimates of myclobutanil in surface waters are
derived from water quality models that use conservative assumptions
(health-protective) regarding the pesticide transport from the point of
application to surface and ground water. Because EPA considers the
aggregate risk resulting from multiple exposure pathways associated
with a pesticide's uses, levels of concern in drinking water may vary
as those uses change. If new uses are added in the future, EPA will
reassess the potential impacts of myclobutanil on drinking water as a
part of the aggregate risk assessment process.
    3. From non-dietary exposure. Myclobutanil is currently registered
for use on the following residential non-food sites: outdoor
residential and greenhouse use on annuals, perennials, turf, shrubs,
trees, and flowers.
    Short- and intermediate-term exposure and risk.  EPA has determined
that these uses do not constitute a chronic exposure scenario, but may
constitute a short- to intermediate-term exposure scenario. The
intermediate-term potential exposure would come from Post-application
(dermal for adult; and dermal + ingestion of soil only, due to the
persistence of the pesticide in soil, for toddlers). Other
intermediate-term exposure scenarios are unlikely as dissipation is
strongly influenced by the growth of the grass which needs weekly
mowing (more frequently in spring) and most dissipation studies on
lawns show considerable tailing off of residues by day 3 or 4; thus,
the expectation of significant residues is very unlikely.
    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." 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

[[Page 37293]]

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 myclobutanil 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,
myclobutanil 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 myclobutanil has a common mechanism of
toxicity with other substances.

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

    1. Chronic risk. Using the partially refined exposure assumptions
described above, EPA has concluded that aggregate exposure (food,
water, and residential) to myclobutanil will not exceed EPA's level of
concern. For the U.S. population, 17% of the RfD is occupied by dietary
(food) exposure. The estimated average concentrations of myclobutanil
in surface and ground water are less than EPA's levels of concern for
myclobutanil in drinking water as a contribution to chronic aggregate
exposure. Therefore, EPA concludes with reasonable certainty that
residues of myclobutanil in drinking water do not contribute
significantly to the aggregate chronic human health risk at the present
time considering the present uses and uses proposed in this action. EPA
has determined that the outdoor registered uses of myclobutanil would
not fall under a chronic exposure scenario. EPA concludes that there is
a reasonable certainty that no harm will result from aggregate chronic
exposure to myclobutanil residues.
    2. Short- and intermediate-term risk. Short- and intermediate-term
aggregate exposure takes into account chronic dietary food and water
(considered to be a background exposure level) plus indoor and outdoor
residential exposure. The short-term NOEL for dermal exposure is based
on a dermal exposure toxicity study. Since the NOEL is based on a
dermal study, oral exposures generally cannot be used directly to
calculate a short-term aggregate exposure. However, as EPA determined
that a dermal absorption factor of 100% should be used for risk
assessment, oral exposures need not be multiplied by a modifying factor
(converted to dermal equivalents) so that they can be compared to the
dermal endpoint. Calculated MOEs were acceptable.
    There is a potential for short-term exposure from drinking water.
However, as estimated average concentrations of myclobutanil in surface
and ground water are less than EPA's levels of concern for drinking
water as a contribution to chronic aggregate and acute aggregate
exposures, contribution to short-term exposure should not exceed EPA's
levels of concern either.
     EPA concludes that short-term aggregate MOEs for adults are
acceptable considering the default assumptions used in the derivation
of exposure estimates and the fact that a LOEL was not identified in
the 28-day rat dermal toxicity study [the HDT was the NOEL in this
study] used to determine the MOE. Chemical-specific dissipation data
and residential use/usage information are required to further refine
these post-application exposure estimates.
    3.  Intermediate-term aggregate risk. There is a potential for
intermediate-term exposure from drinking water. However, as estimated
average concentrations of myclobutanil in surface and ground water are
less than EPA's levels of concern for drinking water as a contribution
to chronic aggregate and acute aggregate exposures, contribution to
intermediate-term exposure should not exceed EPA's levels of concern
either.

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

    1. Safety factor for infants and children-- i. In general. In
assessing the potential for additional sensitivity of infants and
children to residues of myclobutanil, EPA considered data from
developmental toxicity studies in the rat and rabbit and a two-
generation reproduction study in the rat. The developmental toxicity
studies are designed to evaluate adverse effects on the developing
organism resulting from maternal pesticide exposure during gestation.
Reproduction studies provide information relating to effects from
exposure to the pesticide on the reproductive capability of mating
animals and data on systemic toxicity.
    FFDCA section 408 provides that EPA shall apply an additional
tenfold margin of safety for infants and children in the case of
threshold effects to account for pre-and post-natal toxicity and the
completeness of the database unless EPA determines that a different
margin of safety will be safe for infants and children. Margins of
safety are incorporated into EPA risk assessments either directly
through use of a MOE analysis or through using uncertainty (safety)
factors in calculating a dose level that poses no appreciable risk to
humans. EPA believes that reliable data support using the standard MOE
and uncertainty factor (usually 100 for combined inter- and intra-
species variability)) and not the additional tenfold MOE/uncertainty
factor when EPA has a complete data base under existing guidelines and
when the severity of the effect in infants or children or the potency
or unusual toxic properties of a compound do not raise concerns
regarding the adequacy of the standard MOE/safety factor.
    ii. Developmental toxicity studies-- a. Rats. In the developmental
study in rats, the maternal (systemic) NOEL was 93.8 mg/kg/day, based
on rough hair coat, and salivation at the LOEL of 312.6 mg/kg/day. The
developmental (fetal) NOEL was 93.8 mg/kg/day based on incidences of
14th rudimentary and 7th cervical ribs at the LOEL of 312.6 mg/kg/day.
    b.  Rabbits. In the developmental toxicity study in rabbits, the
maternal (systemic) NOEL was 60 mg/kg/day, based on reduced weight
gain, clinical signs of toxicity and abortions at the

[[Page 37294]]

LOEL of 200 mg/kg/day. The developmental (fetal) NOEL was 60 mg/kg/day,
based on increases in number of resorptions, decreases in litter size,
and a decrease in the viability index at the LOEL of 200 mg/kg/day.
    iii. Reproductive toxicity study--Rats. In the 2-generation
reproductive toxicity study in rats, the parental (systemic) NOEL was
2.5 mg/kg/day, based on increased liver weights and liver cell
hypertrophy at the LOEL of 10 mg/kg/day. The developmental (pup) NOEL
was 10 mg/kg/day, based on decreased pup body weight during lactation
at the LOEL of 50 mg/kg/day. The reproductive (pup) NOEL was 10 mg/kg/
day, based on the increased incidence of stillborns, and atrophy of the
testes, epididymides, and prostate at the lowest effect level of 50 mg/
kg/day.
    iv. Pre- and post-natal sensitivity.  The pre- and post-natal
toxicology data base for myclobutanil is complete with respect to
current toxicological data requirements. Based on the developmental and
reproductive toxicity studies discussed above, for myclobutanil there
does not appear to be an extra sensitivity for pre- or post-natal
effects.
    v. Conclusion. Based on the above, EPA concludes that reliable data
support use of a hundredfold margin of exposure/uncertainty factor,
rather than the standard thousandfold margin/factor, to protect infants
and children.
    2. Chronic risk. Using the partially refined exposure assumptions
described above, EPA has concluded that the percent of the RfD that
will be utilized by dietary (food only) exposure to residues of
myclobutanil ranges from 25% for nursing infants (< 1 year old) up to
75% for non-nursing infants (< 1 year old). Despite the potential for
exposure to myclobutanil in drinking water, HED does not expect the
chronic 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 aggregate exposure to myclobutanil residues.
    3. Short-term aggregate risk. The short-term NOEL for dermal
exposure is based on a dermal exposure toxicity study. Since the NOEL
is based on a dermal study, oral exposures generally cannot be used
directly to calculate a short-term aggregate exposure. However, as EPA
determined that a dermal absorption factor of 100% should be used for
risk assessment, oral exposures need not be multiplied by a modifying
factor (converted to dermal equivalents) so that they can be compared
to the dermal endpoint.
    The chronic dietary exposure and calculated dietary MOE for infants
(non-nursing, < 1 year old) was acceptable. For the short-term
aggregate risk of the most highly exposed subgroup (non-nursing infants
(< 1 year old)), the calculated MOE is 120. There is a potential for
short-term exposure from drinking water. However, as estimated average
concentrations of myclobutanil in surface and ground water are less
than EPA's levels of concern for drinking water as a contribution to
chronic aggregate and acute aggregate exposures, contribution to short-
term exposure should not exceed EPA's levels of concern either. EPA
concludes that short-term aggregate MOEs for non-nursing infants (< 1
year old) are acceptable.
    4. Intermediate-term aggregate risk. The intermediate-term NOEL for
dermal exposure is based on an oral exposure toxicity study. EPA has
determined that a dermal absorption factor of 100% should be used for
this risk assessment. The chronic dietary exposure from myclobutanil is
0.018836 mg/kg/day. The calculated myclobutanil dietary MOE for non-
nursing infants (< 1 year old) is 530, which is acceptable. There is a
potential for intermediate-term exposure from drinking water. However,
as estimated average concentrations of myclobutanil in surface and
ground water are less than EPA's levels of concern for drinking water
as a contribution to chronic aggregate and acute aggregate exposures,
contribution to intermediate-term exposure should not exceed EPA's
levels of concern either.

V. Other Considerations

A. Metabolism in Plants and Animals

    The nature of the residue in plants is adequately understood. The
residue of concern is myclobutanil plus its alcohol metabolite (free
and bound), as specified in 40 CFR 180.443(a).

B. Analytical Enforcement Methodology

    An adequate enforcement method is available to enforce the
established tolerances. Quantitation is by GLC using an Nitrogen/
Phosphorus detector for myclobutanil and an Electron Capture detector
(Ni63) for residues measured as the alcohol metabolite. A
copy of this method is on file within EPA, using the identification
code of PP 4E4302.

C. Magnitude of Residues

    Six field trials were conducted between 1992 and 1994 in OH (2), WA
(1), MS (1), NJ (1), and OR (1). In all but one trial, eight
applications of rates ranging from 0.15-1.0 oz. ai/A were made. The one
trial had only four applications. Blackberries and raspberries were
harvested at 0, 3, and 7 PHI, except in one raspberry trial in which
the PHIs were 0, 4, and 8 day. The results at 1X show a range of
residues of 0.03-0.39 ppm for parent myclobutanil and < 0.02 for the
alcohol metabolite. Residues of myclobutanil and its alcohol metabolite
are not expected to exceed 1.0 ppm in/on caneberries as a result of
this section 18 use. A time-limited tolerance for the combined residues
of myclobutanil and its alcohol metabolite (free and bound) should be
established at this level.
    Secondary residues are not expected in animal commodities as no
feedstuffs are associated with these section 18 uses. Meat/milk/
poultry/egg tolerances have been established as a result of other
myclobutanil uses.

D. International Residue Limits

    There are no Codex, Canadian or Mexican residue limits established
for myclobutanil and its metabolites on the commodities included in
these section 18 requests. Thus, harmonization is not an issue for
these section 18 actions.

E. Rotational Crop Restrictions

    Information concerning the likelihood of residues in rotational
crops is not available for myclobutanil. As caneberries and hopes are
normally not rotated, issues pertaining to rotational crops are not
applicable to this petition.

VI. Conclusion

    Therefore, the tolerance is established for combined residues of
myclobutanil in caneberries at 1.0 ppm; and for combined residues of
myblobutanil in/on dried hop cones at 5.0 ppm.

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 September 8, 1998, file written objections to
any aspect of this regulation and may also request a hearing on those
objections.

[[Page 37295]]

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
Confidential Business Information (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 and Electronic Submissions

    EPA has established a record for this rulemaking under docket
control number [OPP-300678] (including any comments and data submitted
electronically). A public version of this record, including printed,
paper versions of electronic comments, which does not include any
information claimed as CBI, is available for inspection from 8:30 a.m.
to 4 p.m., Monday through Friday, excluding legal holidays. The public
record is located in Room 119 of the Public Information and Records
Integrity Branch, Information Resources and Services Division (7502C),
Office of Pesticide Programs, Environmental Protection Agency, Crystal
Mall #2, 1921 Jefferson Davis Highway, Arlington, VA.
    Electronic comments may be sent directly to EPA at:
    opp-docket@epamail.epa.gov.

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

IX. Regulatory Assessment Requirements

    This action finalizes a tolerance under FFDCA section 408(e). 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). In addition, 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 Address Environmental Justice in Minority
Populations and Low-Income Populations (59 FR 7629, February 16, 1994),
or require special 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, under the Regulatory Flexibility Act (RFA) (5 U.S.C.
601 et seq.), the Agency 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.

X. 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 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: June 25, 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. 180.443, by adding new entries for caneberries and hop
cones, dried in alphabetical order to the table in paragraph (b), to
read as follows:

 Sec. 180.443   Myclobutanil; tolerances for residues.

*        *        *        *        *
    (b) Section 18 emergency exemptions. *    *    *

------------------------------------------------------------------------
                                                             Expiration/
                   Commodity                     Parts per    Revocation
                                                  million        Date
------------------------------------------------------------------------
Caneberries...................................          1.0     12/31/99

          *            *            *            *            *
Hop cones, dried..............................          5.0     12/31/99

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

*        *        *        *        *

[FR Doc. 98-18278 Filed 7-9-98; 8:45 am]
BILLING CODE 6560-50-F