Document ID: EPA-HQ-OPP-2006-0282-0003
Agency: epa
Document Type: Rule
Title: Myclobutanil; Pesticide Tolerance
Posted Date: 2006-12-20T05:00Z

[Federal Register: December 20, 2006 (Volume 71, Number 244)]
[Rules and Regulations]               
[Page 76167-76173]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr20de06-13]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2006-0282; FRL-8105-1]

 
Myclobutanil; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes tolerances for combined residues 
of myclobutanil in or on hops, soybean seed, soybean forage, soybean 
hay, aspirated grain fractions, and soybean refined oil. Interregional 
Research Project 4 (IR-4) requested the tolerance for hops and 
Dow AgroSciences requested the tolerances for the soybean commodities 
under the Federal Food, Drug, and Cosmetic Act (FFDCA), as amended by 
the Food Quality Protection Act of 1996 (FQPA).

DATES: This regulation is effective December 20, 2006. Objections and 
requests for hearings must be received on or before February 20, 2007, 
and must be filed in accordance with the instructions provided in 40 
CFR part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).

ADDRESSES:  EPA has established a docket for this action under docket 
identification (ID) number EPA-HQ-OPP-2006-0282. All documents in the 
docket are listed in the index for the docket. Although listed in the 
index, some information is not publicly available, e.g., Confidential 
Business Information (CBI) or other information whose disclosure is 
restricted by statute. Certain other material, such as copyrighted 
material, is not placed on the Internet and will be publicly available 
only in hard copy form. Publicly available docket materials are 
available in the electronic docket at http://www.regulations.gov, or, 

if only available in hard copy, at the OPP Regulatory Public Docket in 
Rm. S-4400, One Potomac Yard (South Building), 2777 S. Crystal Drive, 
Arlington, VA. The Docket Facility is open from 8:30 a.m. to 4 p.m., 
Monday through Friday, excluding legal holidays. The Docket telephone 
number is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: Barbara Madden, Registration Division 
(7505P), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone 
number: (703) 305-6463; e-mail address: madden.barbara@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

    You may be potentially affected by this action if you are an 
agricultural producer, food manufacturer, or pesticide manufacturer. 
Potentially affected entities may include, but are not limited to:
     Crop production (NAICS 111), e.g., agricultural workers; 
greenhouse, nursery, and floriculture workers; farmers.
     Animal production (NAICS 112), e.g., cattle ranchers and 
farmers, dairy cattle farmers, livestock farmers.
     Food manufacturing (NAICS 311), e.g., agricultural 
workers; farmers; greenhouse, nursery, and floriculture workers; 
ranchers; pesticide applicators.
     Pesticide manufacturing (NAICS 32532), e.g., agricultural 
workers; commercial applicators; farmers; greenhouse, nursery, and 
floriculture workers; residential users.
    This listing is not intended to be exhaustive, but rather provides 
a guide for readers regarding entities likely to be affected by this 
action. Other types of entities not listed in this unit could also be 
affected. The North American Industrial Classification System (NAICS) 
codes have been provided to assist you and others in determining 
whether this action might apply to certain entities. If you have any 
questions regarding the applicability of this action to a particular 
entity, consult the person listed under FOR FURTHER INFORMATION 
CONTACT.

B. How Can I Access Electronic Copies of this Document?

    In addition to accessing an electronic copy of this Federal 
Register document through the electronic docket at http://www.regulations.gov
, you may access this Federal Register document 

electronically through the EPA Internet under the ``Federal Register'' 
listings at http://www.epa.gov/fedrgstr. You may also access a 

frequently updated electronic version of 40 CFR part 180 through the 
Government Printing Office's pilot e-CFR site at http://www.gpoaccess.gov/ecfr
.

C. Can I File an Objection or Hearing Request?

    Under section 408(g) of the FFDCA, as amended by the FQPA, any 
person may file an objection to any aspect of this regulation and may 
also request a hearing on those objections. The EPA procedural 
regulations which govern the submission of objections and requests for 
hearings appear in 40 CFR part 178. You must file your objection or 
request a hearing on this regulation in accordance with the 
instructions provided in 40 CFR part 178. To ensure proper receipt by 
EPA, you must identify docket ID number EPA-HQ-OPP-2006-0282 in the 
subject line on the first page of your submission. All requests must be 
in writing, and must be mailed or delivered to the Hearing Clerk on or 
before February 20, 2007.
    In addition to filing an objection or hearing request with the 
Hearing Clerk as described in 40 CFR part 178, please submit a copy of 
the filing that does not contain any CBI for inclusion in the public 
docket that is described in ADDRESSES. Information not marked 
confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA 
without prior notice. Submit your copies, identified by docket ID 
number EPA-HQ-OPP-2006-0282, by one of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov. 

Follow the on-line instructions for submitting comments.

[[Page 76168]]

     Mail: Office of Pesticide Programs (OPP) Regulatory Public 
Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania 
Ave., NW., Washington, DC 20460-0001.
     Delivery: OPP Regulatory Public Docket (7502P), 
Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South 
Building), 2777 S. Crystal Drive, Arlington, VA. Deliveries are only 
accepted during the Docket's normal hours of operation (8:30 a.m. to 4 
p.m., Monday through Friday, excluding legal holidays). Special 
arrangements should be made for deliveries of boxed information. The 
Docket telephone number is (703) 305-5805.

II. Background and Statutory Findings

    In the Federal Register of April 12, 2006 (71 FR 18740) (FRL-7773-
9), EPA issued a notice pursuant to section 408(d)(3) of FFDCA, 21 
U.S.C. 346a(d)(3), announcing the filing of a pesticide petition (PP 
1E6265) by Interregional Research Project No. 4 (IR-4), 500 College 
Road East, Suite 201 W, Princeton, NJ 08540. The petition requested 
that 40 CFR 180.443 be amended by establishing a tolerance for combined 
residues of the fungicide myclobutanil, alpha-butyl-alpha-(4-
chlorophenyl)-1H-1,2,4-triazole-1-propanenitrile and its alcohol 
metabolite (alpha-(3-hydroxybutyl)-alpha-(4-chlorophenyl)-1H-1,2,4-
triazole-1-propanenitrile (free and bound), in or on hop, dried cones 
at 10 parts per million (ppm). That notice included a summary of the 
petition prepared by Dow AgroSciences, the registrant. There were no 
comments received in response to the notice of filing.
    In the Federal Register of August 23, 2006 (71 FR 49448) (FRL-8073-
2), EPA issued a notice pursuant to section 408(d)(3) of FFDCA, 21 
U.S.C. 346a(d)(3), announcing the filing of a pesticide petition (PP 
5F6997) by Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN 
46268. The petition requested that 40 CFR 180.443 be amended by 
establishing tolerances for combined residues of the fungicide 
myclobutanil, alpha-butyl-alpha-(4-chlorophenyl)-1H-1,2,4-triazole-1-
propanenitrile and its alcohol metabolite (alpha-(3-hydroxybutyl)-
alpha-(4-chlorophenyl)-1H-1,2,4-triazole-1-propanenitrile (free and 
bound), in or on soybean, aspirated grain fractions at 1.1 ppm; 
soybean, forage at 5.0 ppm; soybean, hay at 13.0 ppm; soybean, hulls at 
0.06 ppm; soybean, meal at 0.03 ppm; soybean, oil at 0.1 ppm; and 
soybean, seed at 0.05 ppm. That notice included a summary of the 
petition prepared by Dow AgroSciences, the registrant. There were no 
comments received in response to the notice of filing.
    Upon completing review of the current myclobutanil database, the 
Agency concluded that the appropriate tolerance levels for myclobutanil 
residues in or on pending crops should be established as follows: Hop, 
dried cones at 10 ppm; soybean, seed at 0.25 ppm; soybean, forage at 
3.5 ppm; soybean, hay at 15 ppm; aspirated grain fractions at 35 ppm; 
and soybean, refined oil at 0.40 ppm. In addition, the proposed 
tolerances for soybean, hulls and soybean, meal were withdrawn because 
based on available processing data, tolerances for these commodities 
are not needed.
    EPA is also deleting several established tolerances in 40 CFR 
180.443(b) that are no longer needed as a result of this action. The 
tolerance deletions under 40 CFR 180.443(b) are time-limited tolerances 
established under section 18 emergency exemptions that are superseded 
by the establishment of general tolerances for myclobutanil and its 
metabolites under 40 CFR 180.443(a).
    The revisions to 40 CFR 180.443(b) are as follows:
    Delete the time-limited tolerance for hop, dried cone at 5.0 ppm. A 
tolerance for hop, dried cones at 10 ppm is established by this action 
under 40 CFR 180.443(a).
    Delete the time-limited tolerance for soybean at 0.05 ppm. A 
tolerance for soybean, seed at 0.25 ppm is established by this action 
under 40 CFR 180.443(a).
    Section 408(b)(2)(A)(i) of 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) of FFDCA 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) of FFDCA requires EPA to give special 
consideration to exposure of infants and children to the pesticide 
chemical residue in establishing a tolerance and to ``ensure that there 
is a reasonable certainty that no harm will result to infants and 
children from aggregate exposure to the pesticide chemical 
residue....''
    EPA performs a number of analyses to determine the risks from 
aggregate exposure to pesticide residues. For further discussion of the 
regulatory requirements of section 408 of the FFDCA and a complete 
description of the risk assessment process, see http://www.epa.gov/fedrgstr/EPA-PEST/1997/November/Day-26/p30948.htm
.

III. Aggregate Risk Assessment and Determination of Safety

    Consistent with section 408(b)(2)(D) of FFDCA, EPA has reviewed the 
available scientific data and other relevant information in support of 
this action. EPA has sufficient data to assess the hazards of and to 
make a determination on aggregate exposure, consistent with section 
408(b)(2) of FFDCA, for tolerances for combined residues of 
myclobutanil alpha-butyl-alpha-(4-chlorophenyl)-1H-1,2,4-triazole-1-
propanenitrile and its alcohol metabolite (alpha-(3-hydroxybutyl)-
alpha-(4-chlorophenyl)-1H-1,2,4-triazole-1-propanenitrile (free and 
bound), in or on hop, dried cones at 10 ppm; soybean, seed at 0.25 ppm; 
soybean, forage at 3.5 ppm; soybean, hay at 15 ppm; grain, aspirated 
fractions at 35 ppm; and soybean, refined oil at 0.40 ppm. EPA's 
assessment of exposures and risks associated with establishing these 
tolerances follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its 
validity, completeness, and reliability as well as the relationship of 
the results of the studies to human risk. EPA has also considered 
available information concerning the variability of the sensitivities 
of major identifiable subgroups of consumers, including infants and 
children. Specific information on the studies received and the nature 
of the toxic effects caused by myclobutanil as well as the no-observed-
adverse-effect-level (NOAEL) and the lowest-observed-adverse-effect-
level (LOAEL) from the toxicity studies can be found at http://www.epa.gov/fedrgstr/EPA-PEST/2000/May/Day-10/p11571.htm
 (Federal 

Register of May 10, 2000 (65 FR 29963) (FRL-6555-5).

B. Toxicological Endpoints

    For hazards that have a threshold below which there is no 
appreciable risk, the NOAEL from the toxicology study identified as 
appropriate for use in risk assessment is used to estimate the 
toxicological level of concern (LOC). However, the LOAEL is sometimes 
used for risk assessment if no NOAEL was achieved in the toxicology 
study selected. An uncertainty factor (UF) is applied to reflect 
uncertainties inherent in the extrapolation from laboratory

[[Page 76169]]

animal data to humans and in the variations in sensitivity among 
members of the human population as well as other unknowns.
    The linear default risk methodology (Q*) is the primary method 
currently used by the Agency to quantify non-threshold hazards such as 
cancer. The Q* approach assumes that any amount of exposure will lead 
to some degree of cancer risk, estimates risk in terms of the 
probability of occurrence of additional cancer cases. More information 
can be found on the general principles EPA uses in risk 
characterization at http://www.epa.gov/pesticides/health/human.htm.

    A summary of the toxicological endpoints for myclobutanil used for 
human risk assessment can be found at http://www.regulations.gov in document 

0002 (pages 6 and 7) in docket ID number EPA-HQ-OPP-2006-0282. To 
locate this information on the Regulations.gov website follow these 
steps:
     Select ``Advanced Search'', then ``Docket Search''
     In the ``Keyword'' field type the chemical name or insert 
the applicable ``Docket ID number.'' (example: EPA-HQ-OPP-2005-9999)
     Click the ``Submit'' button.
     Follow the instructions on the regulations.gov web site to view 
the index for the docket and access available documents.

C. Exposure Assessment

    1. Dietary exposure 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 
also been established for combined residues of myclobutanil in or on 
milk, egg, and fat, liver, meat, and meat byproducts of cattle, goat, 
hog, horse, and sheep as well as fat, meat, and meat byproducts of 
poultry. Risk assessments were conducted by EPA to assess dietary 
exposures from myclobutanil in food as follows:
    i. Acute exposure. Quantitative acute dietary exposure and 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.
    An acute dietary exposure assessment was performed for females 13-
49 years old (no endpoint was identified for the general U.S. 
population or any other population subgroup). In conducting the acute 
dietary exposure assessment EPA used the Dietary Exposure Evaluation 
Model software with the Food Commodity Intake Database (DEEM-FCID\TM\), 
which incorporates food consumption data as reported by respondents in 
the United States Department of Agriculture (USDA) 1994-1996 and 1998 
Nationwide Continuing Surveys of Food Intake by Individuals (CSFII), 
and accumulated exposure to the chemical for each commodity. The 
following assumptions were made for the acute exposure assessments: 
Tolerance-level residues and 100 percent crop treated (PCT) information 
for all registered and proposed uses.
    ii. Chronic exposure. In conducting the chronic dietary exposure 
assessment EPA used the Dietary Exposure Evaluation Model software with 
the Food Commodity Intake Database (DEEM-FCID\TM\), which incorporates 
food consumption data as reported by respondents in the USDA 1994-1996 
and 1998 Nationwide Continuing Surveys of Food Intake by Individuals 
(CSFII), and accumulated exposure to the chemical for each commodity. 
The following assumptions were made for the chronic exposure 
assessments: A partially refined, chronic dietary exposure assessment 
was performed for the general U.S. population and various population 
subgroups using USDA Pesticide Data Program (PDP) monitoring data for 
apple juice, bananas (not plantains) and milk and assuming all other 
commodities covered by registered and proposed tolerances have residues 
at the appropriate tolerance value. Average PCT information was used 
for apple (except juice), apricots, asparagus, blackberry, cantaloupe, 
cherry, cucumber, grape, nectarine, peach, plum, pumpkin, raspberry, 
squash, strawberry, tomato, and watermelon; 100 PCT was assumed for all 
other registered and proposed uses.
    iii. Cancer. The Agency has classified myclobutanil as Group E - 
not likely to be a human carcinogen. Myclobutanil was determined to be 
not carcinogenic in two acceptable animal studies. Therefore, a cancer 
dietary exposure assessment was not performed.
    iv. Anticipated residue and PCT information. Section 408(b)(2)(F) 
of FFDCA states that the Agency may use data on the actual percent of 
food treated for assessing chronic dietary risk only if the Agency can 
make the following findings: Condition 1, that the data used are 
reliable and provide a valid basis to show what percentage of the food 
derived from such crop is likely to contain such pesticide residue; 
Condition 2, that the exposure estimate does not underestimate exposure 
for any significant subpopulation group; and Condition 3, if data are 
available on pesticide use and food consumption in a particular area, 
the exposure estimate does not understate exposure for the population 
in such area. In addition, the Agency must provide for periodic 
evaluation of any estimates used. To provide for the periodic 
evaluation of the estimate of PCT as required by section 408(b)(2)(F) 
of FFDCA, EPA may require registrants to submit data on PCT.
    The Agency used PCT information as follows:
    40% of apples (except juice), 25% of apricots, 5% of asparagus, 15% 
of blackberry, 10 % of cantaloupe, 35 % of cherry, 1% of cucumber, 25% 
of grape, 15% of nectarine, 10% of peach, 10% of plum, 15% of pumpkin, 
25% of raspberry, 10% of squash, 35% of strawberry, 5% of tomato, and 
5% of watermelon.
    EPA uses an average PCT for chronic dietary risk analysis. The 
average PCT figure for each existing use is derived by combining 
available federal, state, and private market survey data for that use, 
averaging by year, averaging across all years, and rounding up to the 
nearest multiple of five percent except for those situations in which 
the average PCT is less than one. In those cases < 1% is used as the 
average and < 2.5% is used as the maximum.
    EPA uses a maximum PCT for acute dietary risk analysis. The maximum 
PCT figure is the single maximum value reported overall from available 
federal, state, and private market survey data on the existing use, 
across all years, and rounded up to the nearest multiple of five 
percent. In most cases, EPA uses available data from USDA/National 
Agricultural Statistics Service (USDA/NASS), Proprietary Market 
Surveys, and the National Center for Food and Agriculture Policy 
(NCFAP) for the most recent six years.
    The Agency believes that the three conditions listed in Unit 
III.C.iv. have been met. With respect to Condition 1, PCT estimates are 
derived from Federal and private market survey data, which are reliable 
and have a valid basis. The Agency is reasonably certain that the 
percentage of the food treated is not likely to be an underestimation. 
As to Conditions 2 and 3, regional consumption information and 
consumption information for significant subpopulations is taken into 
account through EPA's computer-based model for evaluating the exposure 
of significant subpopulations including several regional groups. Use of 
this consumption information in EPA's risk assessment process ensures 
that EPA's exposure estimate does not understate exposure for any 
significant subpopulation group and allows the

[[Page 76170]]

Agency to be reasonably certain that no regional population is exposed 
to residue levels higher than those estimated by the Agency. Other than 
the data available through national food consumption surveys, EPA does 
not have available information on the regional consumption of food to 
which myclobutanil may be applied in a particular area.
    3. Dietary exposure from drinking water. The Agency lacks 
sufficient monitoring exposure data to complete a comprehensive dietary 
exposure analysis and risk assessment for myclobutanil in drinking 
water. Because the Agency does not have comprehensive monitoring data, 
drinking water concentration estimates are made by reliance on 
simulation or modeling taking into account data on the physical 
characteristics of myclobutanil. Further information regarding EPA 
drinking water models used in pesticide exposure assessment can be 
found at http://www.epa.gov/oppefed1/models/water/index.htm.

    Based on the PRZM/EXAMS and SCI-GROW models, the estimated 
environmental concentrations (EECs) of myclobutanil for acute exposures 
are estimated to be 15.3 parts per billion (ppb) for surface water and 
0.35 ppb for ground water. The EECs for chronic exposures are estimated 
to be 8.5 ppb for surface water and 0.35 ppb for ground water.
    Modeled estimates of drinking water concentrations were directly 
entered into the dietary exposure model (DEEM-FCID\TM\). The estimates 
were calculated using the application rate for hops, which has the 
highest use rate among all existing and proposed uses. For acute 
dietary risk assessment the 1- in 10-year peak acute of 15.3 ppb was 
used to assess the contribution to drinking water and for chronic 
dietary risk assessment the 1- in 10-year estimated annual mean of 8.5 
ppb was used to assess the contribution to drinking water.
    4. From non-dietary exposure. The term ``residential exposure'' is 
used in this document to refer to non-occupational, non-dietary 
exposure (e.g., for lawn and garden pest control, indoor pest control, 
termiticides, and flea and tick control on pets).
    Myclobutanil is currently registered for use on the following 
residential non-dietary sites: Turf, ornamentals, and home garden uses 
on fruit trees, nut trees, berries, mint and vegetables. The risk 
assessment was conducted using the following residential exposure 
assumptions:
    The homeowner use with the greatest potential for exposure is 
small-scale lawn application. Since myclobutanil is applied at 7- to 
14-day intervals, only short-term exposure is expected for the 
residential handler. Short- and intermediate-term residential post-
application exposures are also expected.
    The current use patterns and labeling indicate that a variety of 
application equipment could be used by the homeowner to apply 
myclobutanil to ornamental plants, shrubs, fruit trees, home garden 
vegetables and lawns. Therefore, the following scenarios were assessed:
    i. Aerosol Spray Can Application to Ornamentals and Fruit Trees
    ii. Hose End Sprayer Application to Ornamentals and Fruit Trees
    iii. Low-pressure (LP) Handwand Application to Ornamentals
    iv. LP Handwand Application to Vegetables
    v. Ready to use (RTU) Sprayer Application to Vegetables
    vi. Hose End Sprayer Application to Vegetables
    vii. Hose End Sprayer - Mix Your Own - Application to Turf
    viii. Hose End Sprayer - Ready to Use - Application to Turf
    ix. Belly Grinder Application to Turf
    x. Broadcast Spreader Application to Turf
    Unit exposure data were either taken from Pesticide Handler's 
Exposure Database (PHED) or from the home garden and turf application 
studies that were sponsored by the Outdoor Residential Exposure Task 
Force (ORETF).
    Home garden post-application exposures can occur when home 
gardeners perform tasks such as weeding, pruning or hand harvesting 
following application of myclobutanil. In order to address these risks, 
the post-application exposure to home gardens and orchard scenarios 
were assessed based upon the Residential standard operating procedures 
(SOP) 3.0 for Garden Plants and SOP 4.0 for Trees.
    Two dislodgeable foliar residue (DFR) studies on grapes in 
California were used to assess the home garden exposures. The studies 
were performed using airblast sprayers while the proposed home garden 
applications would be made with LP handwand or hose end sprayers. Based 
upon experience with other fungicides, however, it is anticipated that 
DFRs resulting from handwand applications would be similar to DFRs from 
airblast applications. The initial DFR was assumed to be 23% of the 
application rate.
    ``Pick your own'' exposures can occur at commercially operated 
``pick your own'' strawberry farms and orchards where myclobutanil has 
been applied. To address these risks, post-application exposure for 
pick your own strawberries and tree fruit were assessed based upon the 
Residential SOP 15.0 for ``pick your own'' strawberries. The DFR data 
that were used for the home gardener post-application risks were also 
used to assess ``pick your own'' exposures. The exposure estimates used 
for pick your own exposures are considered conservative because that 
scenario is based upon a screening-level transfer coefficient (TC) and 
a dermal absorption factor of 50%.
    The following scenarios were assessed for residential turf post-
application exposures and risks:
    a. Toddlers Playing on Treated Turf
    b. Adults Performing Yard work on Treated Turf
    c. Adults Playing Golf on Treated Turf
    A turf transferable residue (TTR) study was used to assess the turf 
exposures. The field portion of this study was in North Carolina and 
California. The initial TTR for dermal exposures was assumed to be 2.4% 
of the application rate and was based upon an average of the days after 
treatment (DAT) of 0 and DAT of 3 for the California site. The maximum 
application rate for turf of 0.62-0.68 pounds active ingredient per 
acre (lb ai/A) was use to assess the turf exposures.
    Additional information on residential exposure assumptions can be 
found at http://www.regulations.gov (Docket ID number EPA-HQ-OPP-2006-

0282-0005, pages 13 through 17).
    5. Cumulative effects from substances with a common mechanism of 
toxicity. Section 408(b)(2)(D)(v) of the FFDCA 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.''
    Myclobutanil is a member of the triazole-containing class of 
pesticides. Although conazoles act similarly in plants (fungi) by 
inhibiting ergosterol biosynthesis, there is not necessarily a 
relationship between their pesticidal activity and their mechanism of 
toxicity in mammals. Structural similarities do not constitute a common 
mechanism of toxicity. Evidence is needed to establish that the 
chemicals operate by the same, or essentially the same, sequence of 
major biochemical events (EPA, 2002). In conazoles, however, a variable 
pattern of toxicological responses is found. Some are hepatotoxic and 
hepatocarcinogenic in mice. Some induce thyroid tumors in rats. Some

[[Page 76171]]

induce developmental, reproductive, and neurological effects in 
rodents. Furthermore, the conazoles produce a diverse range of 
biochemical events including altered cholesterol levels, stress 
responses, and altered DNA methylation. It is not clearly understood 
whether these biochemical events are directly connected to their 
toxicological outcomes. Thus, there is currently no evidence to 
indicate that conazoles share common mechanisms of toxicity and EPA is 
not following a cumulative risk approach based on a common mechanism of 
toxicity for the conazoles. For information regarding EPA's procedures 
for cumulating effects from substances found to have a common mechanism 
of toxicity, see EPA's website at http://www.epa.gov/pesticides/cumulative
.

    Myclobutanil is a triazole-derived pesticide. This class of 
compounds can form the common metabolite 1,2,4-triazole and two 
triazole conjugates (triazole alanine and triazole acetic acid). To 
support existing tolerances and to establish new tolerances for 
triazole-derivative pesticides, including myclobutanil, U.S. EPA 
conducted a human health risk assessment for exposure to 1,2,4-
triazole, triazole alanine, and triazole acetic acid resulting from the 
use of all current and pending uses of any triazole-derived fungicide. 
The risk assessment is a highly conservative, screening-level 
evaluation in terms of hazards associated with common metabolites 
(e.g., use of a maximum combination of uncertainty factors) and 
potential dietary and non-dietary exposures (i.e., high end estimates 
of both dietary and non-dietary exposures). In addition, the Agency 
retained the additional 10X FQPA safety factor for the protection of 
infants and children. The assessment includes evaluations of risks for 
various subgroups, including those comprised of infants and children. 
The Agency's complete risk assessment is found in the propiconazole 
reregistration docket at http://www.regulations.gov (Docket ID number 

EPA-HQ-OPP-2005-0497).

D. Safety Factor for Infants and Children

    1. In general. Section 408 of FFDCA provides that EPA shall apply 
an additional tenfold margin of safety for infants and children in the 
case of threshold effects to account for prenatal and postnatal 
toxicity and the completeness of the database on toxicity and exposure 
unless EPA determines based on reliable data 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. In 
applying this provision, EPA either retains the default value of 10X 
when reliable data do not support the choice of a different factor, or, 
if reliable data are available, EPA uses a different additional safety 
factor value based on the use of traditional uncertainty factors and/or 
special FQPA safety factors, as appropriate.
    2. Prenatal and postnatal sensitivity. There is no indication of 
quantitative or qualitative increased susceptibility in rats or rabbits 
from in utero and/or postnatal exposure to myclobutanil. In the rat 
developmental toxicity study, maternal toxicity, which included rough 
hair coat and salivation, alopecia, desquamation and red exudate around 
mouth occurs at the same dose level as increases in incidences of 14th 
rudimentary and 7th cervical ribs in the fetuses. The maternal and 
developmental toxicity NOAELs in the rat developmental toxicity study 
were 93.8 mg/kg/day. EPA concludes that there is no evidence 
qualitative susceptibility in rat developmental toxicity study since 
the fetal variations (14th rudimentary ribs and 7th cervical ribs) are 
normal occurance control animals that occurred in the presence severe 
maternal toxicity (red exudate around mouth and salivation). In the 
rabbit developmental toxicity study there is reduced body weight and 
body weight gain during the dosing period, clinical signs of toxicity 
such as bloody urine and bloody urogenital or anal area and a possible 
increase in abortions (blood and/or aborted material in the cage pan) 
in the does at the same dose level as developmental toxicity manifested 
as increased resorptions, decreased litter size and decreased viability 
index. The maternal and developmental toxicity NOAELs in the rabbit 
developmental toxicity study were 93.8 mg/kg/day. EPA concludes that 
there is no evidence qualitative susceptibility in rabbit developmental 
toxicity study since the fetal effects (resorptions, decreased litter 
size and viability) occurred in the presence equally severe maternal 
toxicity (abortions, bloody urine and bloody urogenital or anal area). 
The maternal NOAEL in the 2-generation reproduction study was 50 ppm 
(2.5 mg/kg/day) based on hepatocellular hypertrophy and increased in 
liver weight seen at 200 ppm (10 mg/kg/day; LOAEL). The offspring 
toxicity NOAEL was 200 ppm (10 mg/kg/day) based on decreased in pup 
body weight gain during lactation seen at 1,000 ppm (50 mg/kg/day; 
LOAEL). The reproductive toxicity NOAEL was 200 ppm (10 mg/kg/day) 
based on increased incidences in the number of still born pups and 
atrophy of the testes, epididymides and prostate observed at 1,000 ppm 
(50 mg/kg/day; LOAEL). EPA concludes that there is no evidence on 
increased susceptibility (qualitative or quantitative) in the 2-
generation reproduction study in rats because the offspring and 
reproductive toxicity were observed at a higher dose than the dose that 
caused maternal toxicity.
    3. Conclusion. EPA has determined that reliable data show that it 
would be safe for infants and children to reduce the FQPA safety factor 
to 1X. The decision is base on the following findings:
    i. There is a complete toxicity data base for myclobutanil.
    ii. There was no evidence of increased susceptibility in the 
developmental toxicity studies with rats and rabbits.
    iii. A developmental neurotoxicity study is not required because 
neurotoxic compounds of similar structure were not identified and there 
was no evidence of neurotoxicity in the current toxicity database.
    iv. The exposure assessments will not underestimate the potential 
dietary (food and drinking water) and residential (non-occupational) 
exposures for infants and children from the use of myclobutanil.
    v. The acute dietary food exposure assessment (females 13-49 years 
old only) utilizes existing and proposed tolerance level residues and 
100 PCT information for all commodities. By using these screening-level 
assessments, actual exposures/risks will not be underestimated.
    vi. The chronic dietary food exposure assessment utilizes existing 
and proposed tolerance level residues; USDA Pesticide Data Program 
(PDP) monitoring data for apple juice, bananas (not plantains) and 
milk; average PCT data for some commodities and 100 PCT information for 
all other registered and proposed uses. The chronic assessment is 
somewhat refined and based on reliable data and will not underestimate 
exposure/risk.
    vii. The dietary drinking water assessment utilizes water 
concentration values generated by model and associated modeling 
parameters, which are designed to provide conservative, health 
protective, high-end estimates of water concentrations which will not 
likely be exceeded.
    viii. The residential handler assessment is based upon the 
residential SOPs and utilized unit exposure data

[[Page 76172]]

from the ORETF and the PHED. The residential post-application 
assessment is based upon chemical-specific turf transferable residue 
(TTR) data and DFR data. The chemical-specific study data as well as 
the surrogate study data used are reliable and also are not expected to 
underestimate risk to adults as well as to children. In a few cases 
where chemical-specific data were not available, the SOPs were used 
alone. The residential SOPs are based upon reasonable ``worst-case'' 
assumptions and are not expected to underestimate risk. These 
assessments of exposure are not likely to underestimate the resulting 
estimates of risk from exposure to myclobutanil.

 E. Aggregate Risks and Determination of Safety

    1. Acute risk. Using the exposure assumptions discussed in this 
unit for acute exposure, the acute dietary exposure from food and water 
to myclobutanil will occupy 2.4% of the acute Adjusted Population Dose 
(aPAD) for females 13 years and older. No endpoint was identified for 
the general U.S. population or any other population subgroup. 
Therefore, EPA does not expect the aggregate exposure to exceed 100% of 
the aPAD.
    2. Chronic risk. Using the exposure assumptions described in this 
unit for chronic exposure, EPA has concluded that exposure to 
myclobutanil from food and water will utilize 10% of the chronic 
Population Adjusted Dose (cPAD) for the U.S. population, 17% of the 
cPAD for all infants less that 1 year old, and 25% of the cPAD for 
children 1-2 years old, the subpopulation at greatest exposure. There 
are no residential uses for myclobutanil that result in chronic 
residential exposure. Therefore, chronic residential exposure to 
residues of myclobutanil is not expected. EPA does not expect the 
aggregate exposure to exceed 100% of the cPAD.
    3. Short-term risk. Short-term aggregate exposure takes into 
account residential exposure plus chronic exposure to food and water 
(considered to be a background exposure level). The short-term 
aggregate risk assessments estimate risks likely to result from 1-30 
days of exposure to myclobutanil residues in food, drinking water, and 
residential pesticide uses.
    Myclobutanil is currently registered for uses that could result in 
short-term residential exposure and the Agency has determined that it 
is appropriate to aggregate chronic food, water and short-term 
exposures for myclobutanil.
    Using the exposure assumptions described in this unit for short-
term exposures, EPA has concluded that food, water and residential 
exposures aggregated result in aggregate margin of exposures (MOEs) of 
180 for the general U.S. population for handler exposures; 300 for the 
general U.S. population for home gardens post application exposures; 
110 for the general U.S. population for ``Pick Your Own'' fruit tree 
post application exposures; 130 for the general U.S. population for 
heavy yard work for turf post application exposures; 1,300 for the 
general U.S. population for exposures when playing golf and 130 for 
children 1-2 years old when playing on the lawn post application 
exposures. These aggregate MOEs do not exceed the Agency's LOC for 
aggregate exposure to food, water and residential uses. Therefore, EPA 
does not expect short-term aggregate exposure to exceed the Agency's 
LOC.
    4. Intermediate-term risk. Intermediate-term aggregate exposure 
takes into account residential exposure plus chronic exposure to food 
and water (considered to be a background exposure level). The 
intermediate-term aggregate risk assessment estimates risks likely to 
result from 1 to 6 months exposure to myclobutanil residues in food, 
drinking water, and residential pesticide scenarios.
    Myclobutanil is currently registered for uses that could result in 
intermediate-term residential exposure and the Agency has determined 
that it is appropriate to aggregate chronic food and water and 
intermediate-term exposures for myclobutanil.
    Using the exposure assumptions described in this unit for 
intermediate-term exposures, EPA has concluded that food, water, and 
residential exposures aggregated result in aggregate MOEs of 300 for 
the general U.S. population for home garden post application exposures; 
110 for the general U.S. population for ``Pick Your Own'' fruit tree 
post application exposures; 130 for the general U.S. population for 
heavy yard work for turf post application exposures; 1,300 for the 
general U.S. population for exposures when playing golf and 130 for 
children 1-2 years old when playing on the lawn post application 
exposures. These aggregate MOEs do not exceed the Agency's LOC for 
aggregate exposure to food, water, and residential uses. Therefore, EPA 
does not expect intermediate-term aggregate exposure to exceed the 
Agency's LOC.
    5. Aggregate cancer risk for U.S. population. The Agency has 
classified myclobutanil as Group E - not likely to be a human 
carcinogen. Myclobutanil was determined to be not carcinogenic in two 
acceptable animal studies. Myclobutanil is not expected to pose a 
cancer risk.
    6. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
to the general population, and to infants and children from aggregate 
exposure to myclobutanil residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    An adequate enforcement method is available to enforce the proposed 
tolerances on soybeans and hops. Quantitation is by gas-liquid 
chromatography (GLC) using a nitrogen/phosphorus (N/P) detector for 
myclobutanil and an electron capture detector (Ni63) for residues 
measured as the alcohol metabolite. The EPA has conducted a successful 
method validation of Method 34S-88-10, and the method has been 
forwarded to the Food and Drug Administration (FDA) for inclusion in 
Pesticide Analytical Method Volume II (PAM) Vol. II.
    Enforcement methods for the established tolerances on livestock 
commodities are Methods 34S-88-22, 34S-88-15, 31S-87-02, and 34S-88-21 
These methods have been submitted for publication in PAM II.
    These methods may be requested from: Chief, Analytical Chemistry 
Branch, Environmental Science Center, 701 Mapes Rd., Ft. Meade, MD 
20755-5350; telephone number: (410) 305-2905; e-mail address: 
residuemethods@epa.gov.

B. International Residue Limits

    There are no current Codex, Canadian or Mexican maximum residue 
limits (MRLs) for residues of myclobutanil in/on soybeans. Therefore, 
harmonization is not an issue. There are no current Canadian or Mexican 
maximum residue limits (MRLs) for residues of myclobutanil in/on hops. 
However, there is a Codex MRL of 2 ppm for the parent compound 
myclobutanil in/on hops, dry. EPA has concluded the submitted residue 
chemistry data support a tolerance of 10 ppm for residues of 
myclobutanil and its alcohol metabolite RH-9090 (free and bound). 
Therefore, harmonization with the Codex MRL is not possible.

V. Conclusion

    Therefore, tolerances are established for combined residues of 
myclobutanil alpha-butyl-alpha-(4-chlorophenyl)-1H-1,2,4-triazole-1-
propanenitrile and its alcohol metabolite (alpha-(3-hydroxybutyl)-
alpha-(4-chlorophenyl)-1H-1,2,4-triazole-1-propanenitrile (free

[[Page 76173]]

and bound), in or on hop, dried cones at 10 ppm; soybean, seed at 0.25 
ppm; soybean, forage at 3.5 ppm; soybean, hay at 15 ppm; grain, 
aspirated fractions at 35 ppm; and soybean, refined oil at 0.40 ppm.

VI. Statutory and Executive Order Reviews

    This final rule establishes a tolerance under section 408(d) of 
FFDCA in response to a petition submitted to the Agency. The Office of 
Management and Budget (OMB) has exempted these types of actions from 
review under Executive Order 12866, entitled Regulatory Planning and 
Review (58 FR 51735, October 4, 1993). Because this rule has been 
exempted from review under Executive Order 12866 due to its lack of 
significance, this rule is not subject to Executive Order 13211, 
Actions Concerning Regulations That Significantly Affect Energy Supply, 
Distribution, or Use (66 FR 28355, May 22, 2001). This final rule does 
not contain any information collections subject to OMB approval under 
the Paperwork Reduction Act (PRA), 44 U.S.C. 3501 et seq., or impose 
any enforceable duty or contain any unfunded mandate as described under 
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA) (Public Law 
104-4). Nor does it require any special considerations under Executive 
Order 12898, entitled Federal Actions to Address Environmental Justice 
in Minority Populations and Low-Income Populations (59 FR 7629, 
February 16, 1994); or OMB review or any Agency action under Executive 
Order 13045, entitled Protection of Children from Environmental Health 
Risks and Safety Risks (62 FR 19885, April 23, 1997). This action does 
not involve any technical standards that would require Agency 
consideration of voluntary consensus standards pursuant to section 
12(d) of the National Technology Transfer and Advancement Act of 1995 
(NTTAA), Public Law 104-113, section 12(d) (15 U.S.C. 272 note). Since 
tolerances and exemptions that are established on the basis of a 
petition under section 408(d) of FFDCA, such as the tolerance in this 
final rule, do not require the issuance of a proposed rule, the 
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et 
seq.) do not apply. In addition, the Agency has determined that this 
action will not have a substantial direct effect on States, on the 
relationship between the national government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government, as specified in Executive Order 13132, entitled Federalism 
(64 FR 43255, August 10, 1999). Executive Order 13132 requires EPA to 
develop an accountable process to ensure ``meaningful and timely input 
by State and local officials in the development of regulatory policies 
that have federalism implications.'' ``Policies that have federalism 
implications'' is defined in the Executive order to include regulations 
that have ``substantial direct effects on the States, on the 
relationship between the national government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government.'' This final rule directly regulates growers, food 
processors, food handlers and food retailers, not States. This action 
does not alter the relationships or distribution of power and 
responsibilities established by Congress in the preemption provisions 
of section 408(n)(4) of FFDCA. For these same reasons, the Agency has 
determined that this rule does not have any ``tribal implications'' as 
described in Executive Order 13175, entitled Consultation and 
Coordination with Indian Tribal Governments (65 FR 67249, November 6, 
2000). Executive Order 13175, requires EPA to develop an accountable 
process to ensure ``meaningful and timely input by tribal officials in 
the development of regulatory policies that have tribal implications.'' 
``Policies that have tribal implications'' is defined in the Executive 
order to include regulations that have ``substantial direct effects on 
one or more Indian tribes, on the relationship between the Federal 
Government and the Indian tribes, or on the distribution of power and 
responsibilities between the Federal Government and Indian tribes.'' 
This rule will not have substantial direct effects on tribal 
governments, on the relationship between the Federal Government and 
Indian tribes, or on the distribution of power and responsibilities 
between the Federal Government and Indian tribes, as specified in 
Executive Order 13175. Thus, Executive Order 13175 does not apply to 
this rule.

VII. Congressional Review Act

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

List of Subjects in 40 CFR Part 180

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

    Dated: December 8, 2006.
Donald R. Stubbs,
Acting Director, Registration Division, Office of Pesticide Programs.

0
Therefore, 40 CFR chapter I is amended as follows:

PART 180--[AMENDED]

0
1. The authority citation for part 180 continues to read as follows:

    Authority: 21 U.S.C. 321(q), 346a and 371.

0
2. Section 180.443 is amended:
0
a. In paragraph (a), in the table, by alphabetically adding commodities 
to read as set forth below; and
0
b. In paragraph (b), in the table, by removing the commodities ``Hop, 
dried cone'' and ``Soybean''.

Sec.  180.443   Myclobutanil; tolerances for residues.

    (a) * * *

------------------------------------------------------------------------
                                                              Parts per
                         Commodity                             million
------------------------------------------------------------------------
                                * * * * *
Grain, aspirated fractions.................................           35
                                * * * * *
Hop, dried cones...........................................           10
                                * * * * *
Soybean, forage............................................          3.5
 Soybean, hay..............................................           15
Soybean, refined oil.......................................         0.40
Soybean, seed..............................................         0.25
------------------------------------------------------------------------

* * * * *
[FR Doc. E6-21489 Filed 12-19-06; 8:45 am]

BILLING CODE 6560-50-S