Myclobutanil; Pesticide Tolerances for Emergency Exemptions

Note: EPA no longer updates this information, but it may be useful as a reference or resource.
 [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 <greek-a>-butyl-
<greek-a>-(4-chlorophenyl)-1H-1,2,4-triazole-1-propanenitrile plus its 
alcohol metabolite <greek-a>-(3-hydroxybutyl)-<greek-a>-(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. Q<INF>1</INF>* 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 <greek-a>-butyl-<greek-a>-
(4-chlorophenyl)-1H-1,2,4-triazole-1-propanenitrile and its metabolite 
<greek-a>-(3-hydroxybutyl)-<greek-a>-(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 
(Ni<SUP>63</SUP>) 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
Myclobutanil; Pesticide Tolerances for Emergency Exemptions

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