Document ID: EPA-HQ-OPP-2010-0959-0006
Agency: epa
Document Type: Rule
Title: Pesticide Tolerances: Difenoconazole
Posted Date: 2011-12-30T05:00Z

[Federal Register Volume 76, Number 251 (Friday, December 30, 2011)]
[Rules and Regulations]
[Pages 82157-82163]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-33482]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2010-0959; FRL-9328-6]

Difenoconazole; Pesticide Tolerances

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes tolerances for residues of 
difenoconazole in or on oat and rye commodities, and wheat, hay. 
Syngenta Crop Protection, Incorporated requested these tolerances under 
the Federal Food, Drug, and Cosmetic Act (FFDCA).

DATES: This regulation is effective December 30, 2011. Objections and 
requests for hearings must be received on or before February 28, 2012, 
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-2010-0959. All documents in the 
docket are listed in the docket index available at http://www.regulations.gov. 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 Bldg.), 2777 S. Crystal Dr., Arlington, VA. The Docket 
Facility is open from 8:30 a.m. to 4 p.m., Monday through

[[Page 82158]]

Friday, excluding legal holidays. The Docket Facility telephone number 
is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: Tony Kish, Registration Division, 
Office of Pesticide Programs, Environmental Protection Agency, 1200 
Pennsylvania Ave. NW., Washington, DC 20460-0001; telephone number: 
(703) 308-9443; email address: kish.tony@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 those 
engaged in the following activities:
     Crop production (NAICS code 111).
     Animal production (NAICS code 112).
     Food manufacturing (NAICS code 311).
     Pesticide manufacturing (NAICS code 32532).
    This listing is not intended to be exhaustive, but rather to 
provide 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 get electronic access to other related information?

    You may access a frequently updated electronic version of EPA's 
tolerance regulations at 40 CFR part 180 through the Government 
Printing Office's e-CFR site at http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?&c=ecfr&tpl=/ecfrbrowse/Title40/40tab_02.tpl.

C. How can I file an objection or hearing request?

    Under FFDCA section 408(g), 21 U.S.C. 346a, any person may file an 
objection to any aspect of this regulation and may also request a 
hearing on those objections. 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-2010-0959 in the subject line on the first 
page of your submission. All objections and requests for a hearing must 
be in writing, and must be received by the Hearing Clerk on or before 
February 28, 2012. Addresses for mail and hand delivery of objections 
and hearing requests are provided in 40 CFR 178.25(b).
    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. Information not marked confidential pursuant to 40 CFR part 2 
may be disclosed publicly by EPA without prior notice. Submit a copy of 
your non-CBI objection or hearing request, identified by docket ID 
number EPA-HQ-OPP-2010-0959, by one of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov. 
Follow the on-line instructions for submitting comments.
     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 
Bldg.), 2777 S. Crystal Dr., Arlington, VA. Deliveries are only 
accepted during the Docket Facility'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 Facility telephone number is (703) 305-5805.

II. Summary of Petitioned-For Tolerances

    In the Federal Register of Wednesday, July 20, 2011 (76 FR 43231) 
(FRL-8880-1), 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 0F7785) by Syngenta Crop Protection, Inc., P.O. Box 18300, 
Greensboro, NC 27419. The petition requested that 40 CFR 180.475 be 
amended by establishing tolerances for residues of the fungicide, 
difenoconazole, [1-[2-[2-chloro-4-(4-chlorophenoxy)phenyl]-4-methyl-
1,3-dioxolan-2-ylmethyl]-1H-1,2,4-triazole], in or on oats, forage at 
0.1ppm; oats, hay at 0.1 ppm; oats, straw at 0.1 ppm; oats, grain at 
0.1 ppm; rye, forage at 0.1 ppm; rye, straw at 0.1 ppm; rye, grain at 
0.1 ppm; and wheat, hay at 0.1 ppm. That notice referenced a summary of 
the petition prepared by Syngenta Crop Protection, Inc., the 
registrant, which is available in the docket, http://www.regulations.gov.
    One comment on the notice of filing was received from an anonymous 
submitter. EPA's response to these comments is discussed in Unit IV.C.
    Based upon review of the data supporting this petition, EPA has 
revised the proposed tolerance levels for oat, grain; oat, forage; oat, 
hay; oat, straw; rye, grain; rye, forage; rye, straw; and wheat, hay. 
In addition, EPA modified commodity definitions submitted by the 
registrant, Syngenta Crop Protection, Inc. The reasons for these 
changes are explained in Unit IV.D.

III. Aggregate Risk Assessment and Determination of Safety

    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)(ii)(I) 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 * * 
*''.
    Consistent with section 408(b)(2)(D) of FFDCA, and the factors 
specified in 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 for difenoconazole including 
exposure resulting from the tolerances established by this action. 
EPA's assessment of exposures and risks associated with difenoconazole 
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.

[[Page 82159]]

    Difenoconazole possesses low acute toxicity by the oral, dermal and 
inhalation routes of exposure. It is not an eye or skin irritant and is 
not a sensitizer. Subchronic and chronic studies with difenoconazole in 
mice and rats showed decreased body weights, decreased body weight 
gains and effects on the liver. In an acute neurotoxicity study in 
rats, reduced fore-limb grip strength was observed on day 1 in males 
and clinical signs of neurotoxicity were observed in females at the 
limit dose of 2000 milligrams/kilograms (mg/kg). In a subchronic 
neurotoxicity study in rats, decreased hind limb strength was observed 
in males only at the mid- and high-doses. However, the effects observed 
in acute and subchronic neurotoxicity studies are transient, and the 
dose-response is well characterized with identified no-observed-
adverse-effects-levels (NOAELs). No systemic toxicity was observed at 
the limit dose in the most recently submitted 28-day rat dermal 
toxicity study.
    There is no concern for increased qualitative an/or quantitative 
susceptibility after exposure to difenoconazole in developmental 
toxicity studies in rats and rabbits, and a reproduction study in rats 
as fetal/offspring effects occurred in the presence of maternal 
toxicity. There are no indications in the available studies that organs 
associated with immune function, such as the thymus and spleen, are 
affected by difenoconazole.
    In accordance with the Agency's current policy, difenoconazole is 
classified as ``Suggestive Evidence of Carcingenic Potential'' and EPA 
is using the Margin of Exposure (MOE) approach to assess cancer risk. 
Difenoconazole is not mutagenic, and no evidence of carcinogenicity was 
seen in rats. Evidence for carcinogenicity was seen in mice (liver 
tumors), but statistically significant carcinomas tumors were only 
induced at excessively-high doses. Adenomas (benign tumors) and liver 
necrosis only were seen at 300 parts per million (ppm) (46 and 58 mg/
kg/day in males and females, respectively). Based on excessive toxicity 
observed the two highest doses in the study, the presence of only 
benign tumors and necrosis at the mid-dose, the absence of tumors at 
the study's lower doses, and the absence of genotoxic effects, EPA has 
concluded that the chronic point of departure (POD) from the chronic 
mouse study will be protective of any cancer effects. The POD from this 
study is the NOAEL of 30 ppm (4.7 and 5.6 mg/kg/day in males and 
females, respectively) which was chosen based upon only those 
biological endpoints which were relevant to tumor development (i.e., 
hepatocellular hypertrophy, liver necrosis, fatty changes in the liver 
and bile stasis).
    Specific information on the studies received and the nature of the 
adverse effects caused by difenoconazole as well as the NOAEL and the 
lowest-observed-adverse-effect-level (LOAEL) from the toxicity studies 
can be found at http://www.regulations.gov in document entitled, 
``Difenoconazole Human Health Risk Assessment for Amended Section 3 
Registration to Add Seed Treatment Use on Oats and Rye and Establish a 
Tolerance in/on Wheat Hay,'' dated October 27, 2011 at page number 25 
in docket ID number EPA-HQ-OPP-2010-0959-0007.

B. Toxicological Points of Departure/Levels of Concern

    Once a pesticide's toxicological profile is determined, EPA 
identifies toxicological points of departure (POD) and levels of 
concern to use in evaluating the risk posed by human exposure to the 
pesticide. For hazards that have a threshold below which there is no 
appreciable risk, the toxicological POD is used as the basis for 
derivation of reference values for risk assessment. PODs are developed 
based on a careful analysis of the doses in each toxicological study to 
determine the dose at which the NOAEL and the LOAEL. Uncertainty/safety 
factors are used in conjunction with the POD to calculate a safe 
exposure level--generally referred to as a population-adjusted dose 
(PAD) or a reference dose (RfD)--and a safe margin of exposure (MOE). 
For non-threshold risks, the Agency assumes that any amount of exposure 
will lead to some degree of risk. Thus, the Agency estimates risk in 
terms of the probability of an occurrence of the adverse effect 
expected in a lifetime. For more information on the general principles 
EPA uses in risk characterization and a complete description of the 
risk assessment process, see http://www.epa.gov/pesticides/factsheets/riskassess.htm.
    A summary of the toxicological endpoints for difenoconazole used 
for human risk assessment is discussed in Unit III. B. of the final 
rule published in the Federal Register of June 15, 2011 (76 FR 34877) 
(FRL-8876-4).

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. In evaluating dietary 
exposure to difenoconazole, EPA considered exposure under the 
petitioned-for tolerances as well as all existing difenoconazole 
tolerances in 40 CFR 180.475. EPA assessed dietary exposures from 
difenoconazole 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 1-day or single exposure.
    Such effects were identified for difenoconazole. In estimating 
acute dietary exposure, EPA used food consumption information from the 
United States Department of Agriculture (USDA) 1994-1996 and 1998 
Nationwide Continuing Surveys of Food Intake by Individuals (CSFII). As 
to residue levels in food, EPA used tolerance-level residues, 100 
percent crop treated (PCT), and the available empirical or DEEM\TM\ 
(ver. 7.81) default processing factors.
    ii. Chronic exposure. In conducting the chronic dietary exposure 
assessment EPA used the food consumption data from the USDA 1994-1996 
and 1998 CSFII. As to residue levels in food, EPA assumed tolerance-
level residues for some commodities, average field trial residues for 
the majority of commodities, the available empirical or DEEM\TM\ (ver. 
7.81) default processing factors, and 100 PCT.
    iii. Cancer. Based on the data summarized in Unit III.A., EPA has 
concluded that a nonlinear RfD approach is appropriate for assessing 
cancer risk to difenoconazole. A separate quantitative cancer exposure 
assessment is unnecessary since the NOAEL (4.7 and 5.6 mg/kg/day in 
males and females, respectively) to assess cancer risk is higher than 
the NOAEL (0.96 and 1.27 mg/kg/day in males and females, respectively) 
to assess chronic risks and exposure for the purpose of assessing 
cancer risk would be no higher than chronic exposure. Therefore, the 
chronic dietary risk estimate will be protective of potential cancer 
risk.
    iv. Anticipated residue and percent crop treated (PCT) information. 
EPA did not use PCT information in the dietary assessment for 
difenoconazole. EPA used anticipated residues in the form of average 
field trial residues for the majority of commodities.
    Section 408(b)(2)(E) of FFDCA authorizes EPA to use available data 
and information on the anticipated residue levels of pesticide residues 
in food and the actual levels of pesticide residues that have been 
measured in food. If EPA relies on such information, EPA must require 
pursuant to FFDCA section 408(f)(1) that data be provided 5 years after 
the tolerance is established, modified, or left in effect, 
demonstrating

[[Page 82160]]

that the levels in food are not above the levels anticipated. For the 
present action, EPA will issue such data call-ins as are required by 
FFDCA section 408(b)(2)(E) and authorized under FFDCA section 
408(f)(1). Data will be required to be submitted no later than 5 years 
from the date of issuance of these tolerances.
    2. Dietary exposure from drinking water. The Agency used screening 
level water exposure models in the dietary exposure analysis and risk 
assessment for difenoconazole in drinking water. These simulation 
models take into account data on the physical, chemical, and fate/
transport characteristics of difenoconazole. 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 Pesticide Root Zone Model/Exposure Analysis Modeling 
System (PRZM/EXAMS) for the registered and proposed new uses and 
Screening Concentration in Ground Water (SCI-GROW) models, the 
estimated drinking water concentrations (EDWCs) of difenoconazole for 
acute exposures are estimated to be 15.8 parts per billion (ppb) for 
surface water and 0.0128 ppb for ground water.
    For chronic exposures for non-cancer assessments are estimated to 
be 10.4 ppb for surface water and 0.0128 ppb for ground water.
    Modeled estimates of drinking water concentrations were directly 
entered into the dietary exposure model.
    For acute dietary risk assessment, the water concentration value of 
15.8 ppb was used to assess the contribution to drinking water.
    For chronic dietary risk assessment, the water concentration of 
value 10.4 ppb was used to assess the contribution to drinking water.
    3. 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).
    Difenoconazole is currently registered for the following uses that 
could result in residential exposures: Ornamentals. EPA assessed 
residential exposure using the following assumptions: Adults may be 
exposed to difenoconazole from its currently registered use on 
ornamentals. Residential pesticide handlers may be exposed to short-
term duration (1-30 days) only. The dermal and inhalation (short-term) 
residential exposure was assessed for ``homeowners'' mixer/loader/
applicator wearing short pants and short-sleeved shirts as well as 
shoes plus socks using garden hose-end sprayer, ``pump-up'' compressed 
air sprayer, and backpack sprayer.
    Residential post-application exposure may occur from use of 
difenoconozole on golf course turf. Short-term dermal exposure was 
assessed for post-application exposure to golf course turf. Further 
information regarding EPA standard assumptions and generic inputs for 
residential exposures may be found at http://www.epa.gov/pesticides/trac/science/trac6a05.pdf.
    4. Cumulative effects from substances with a common mechanism of 
toxicity. Section 408(b)(2)(D)(v) of 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.''
    Difenoconazole 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 
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 Web sites at: http://www.epa.gov/pesticides/cumulative and http://www.epa.gov/fedrgstr/EPA_PEST/2002/January/Day_16/.
    Difenoconazole is a triazole-derived pesticide. This class of 
compounds can form the common metabolite 1,2,4-triazole and two 
triazole conjugates (triazolylalanine and triazolylacetic acid). To 
support existing tolerances and to establish new tolerances for 
triazole-derivative pesticides, including difenoconazole, EPA conducted 
a human health risk assessment for exposure to 1,2,4-triazole, 
triazolylalanine, and triazolylacetic 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 risk 
assessment is found in the propiconazole reregistration docket at 
http://www.regulations.gov, Docket Identification (ID) Number EPA-HQ-
OPP-2005-0497 and the most recent update that assessed additional new 
commodities for triazoles may be found in docket ID number EPA-HQ-OPP-
2010-0959 in the document titled ``Common Triazole Metabolites: Updated 
Aggregate Human Health Risk Assessment to Address Tolerance Petitions 
for Metconazole'', dated April 27, 2011. The requested amended uses of 
difenoconazole did not result in an increase in dietary exposure 
estimates for free triazole or conjugated triazoles. Therefore, the 
last dietary exposure analyses cited above addresses potential 
exposures resulting from commodities discussed in this action.

D. Safety Factor for Infants and Children

    1. In general. Section 408(b)(2)(C) of FFDCA provides that EPA 
shall apply an additional tenfold (10x) 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. This 
additional margin of safety is commonly referred to as the FQPA Safety 
Factor (SF). In applying this provision, EPA either retains the default 
value of 10x, or uses a different additional safety factor when 
reliable data available to EPA support the choice of a different 
factor.
    2. Prenatal and postnatal sensitivity. EPA determined that the 
available data

[[Page 82161]]

indicated no increased susceptibility of rats or rabbits to in utero 
and/or postnatal exposure to difenoconazole. In the prenatal 
developmental toxicity studies in rats and rabbits and the 2-generation 
reproduction study in rats, toxicity to the fetuses/offspring, when 
observed, occurred at equivalent or higher doses than in the maternal/
parental animals. In the prenatal developmental toxicity study in rats, 
maternal toxicity was manifested as decreased body weight gain and food 
consumption at the LOAEL of 85 mg/kg/day; the NOAEL was 16 mg/kg/day. 
The developmental toxicity was manifested as alterations in fetal 
ossifications at 171 mg/kg/day; the developmental NOAEL was 85 mg/kg/
day. In a developmental toxicity study in rabbits, maternal and 
developmental toxicity were seen at the same dose level (75 mg/kg/day). 
Maternal toxicity in rabbits was manifested as decreased body weight 
gain and decreased food consumption, while developmental toxicity was 
manifested as decreased fetal weight. In a 2-generation reproduction 
study in rats, there were decreases in maternal body weight gain and 
decreases in body weights of F1 males at the LOAEL of 12.5 mg/kg/day; 
the parental systemic and off spring toxicity NOAEL was 1.25 mg/kg/day.
    3. Conclusion. EPA has determined that reliable data show the 
safety of infants and children would be adequately protected if the 
FQPA SF were reduced to 1x . That decision is based on the following 
findings:
    i. The toxicity database is complete except for an immunotoxicity 
study which is now required as a part of new data requirements in the 
40 CFR part 158 for conventional pesticide registration. However, the 
toxicology database for difenoconazole does not show any evidence of 
treatment-related effects on the immune system. The overall weight of 
evidence suggests that this chemical does not directly target the 
immune system. Accordingly, the Agency does not believe that conducting 
a functional immunotoxicity study will result in a lower point of 
departure POD than that currently in use for overall risk assessment, 
and therefore, a database uncertainty factor is not needed to account 
for lack of this study.
    ii. The acute and subchronic neurotoxicity studies in rats are 
available. These data show that difenoconazole exhibits some evidence 
of neurotoxicity, but the effects are transient or occur at the limit 
dose. EPA concluded that difenoconazole is not a neurotoxic compound. 
Based on the toxicity profile, and lack of neurotoxicity, a 
developmental neurotoxicity study in rats is not required.
    iii. There is no evidence that difenoconazole results in increased 
susceptibility of rats or rabbit fetuses to in utero and/or postnatal 
exposure in the developmental and reproductive toxicity data.
    iv. There are no residual uncertainties identified in the exposure 
databases. A conservative dietary food exposure assessment was 
conducted. Acute dietary food exposure assessments were performed based 
on tolerance-level residues, 100 PCT, and the available empirical or 
DEEM (ver. 7.81) default processing factors.
    Chronic dietary exposure assessments were based on tolerance-level 
residues for some commodities, average field trial residues for the 
majority of commodities, the available empirical or DEEM (ver. 7.81) 
default processing factors, and 100 PCT. These are conservative 
approaches and are unlikely to understate the residues in food 
commodities.
    EPA also made conservative (protective) assumptions in the ground 
water and surface water modeling used to assess exposure to 
difenoconazole in drinking water. Post-application residential exposure 
of children is not expected. These assessments will not underestimate 
the exposure and risks posed by difenoconazole.

E. Aggregate Risks and Determination of Safety

    EPA determines whether acute and chronic dietary pesticide 
exposures are safe by comparing aggregate exposure estimates to the 
aPAD and chronic PAD (cPAD). For linear cancer risks, EPA calculates 
the lifetime probability of acquiring cancer given the estimated 
aggregate exposure. Short-, intermediate-, and chronic-term risks are 
evaluated by comparing the estimated aggregate food, water, and 
residential exposure to the appropriate PODs to ensure that an adequate 
MOE exists.
    1. Acute risk. Using the exposure assumptions discussed in this 
unit for acute exposure, the acute dietary exposure from food and water 
to difenoconazole will occupy 19% of the aPAD for children 1 to 2 years 
old, the population group receiving the greatest exposure.
    2. Chronic risk. Using the exposure assumptions described in this 
unit for chronic exposure, EPA has concluded that chronic exposure to 
difenoconazole from food and water will utilize 46% of the cPAD for 
children 1 to 2 years old, the population group receiving the greatest 
exposure. Based on the explanation in Unit III.C.3., regarding 
residential use patterns, chronic residential exposure to residues of 
difenoconazole is not expected.
    3. Short-term risk. Short-term aggregate exposure takes into 
account short-term residential exposure plus chronic exposure to food 
and water (considered to be a background exposure level).
    Difenoconazole is currently registered for uses on ornamentals that 
could result in short-term residential exposure, and the Agency has 
determined that it is appropriate to aggregate chronic exposure through 
food and water with short-term residential exposures to difenoconazole.
    Using the exposure assumptions described in this unit for short-
term exposures, EPA has concluded the combined short-term food, water, 
and residential exposures result in aggregate MOEs of 260 or greater. 
Because EPA's level of concern for difenoconazole is a MOE of 100 or 
below, these MOEs resulting from short-termed exposure to 
difenoconazole are not of concern.
    4. Intermediate-term risk. Intermediate-term aggregate exposure 
takes into account intermediate-term residential exposure plus chronic 
exposure to food and water (considered to be a background exposure 
level).
    An intermediate-term adverse effect was identified; however, 
difenoconazole is not registered for any use patterns that would result 
in intermediate-term residential exposure. Intermediate-term risk is 
assessed based on intermediate-term residential exposure plus chronic 
dietary exposure. Because there is no intermediate-term residential 
exposure and chronic dietary exposure has already been assessed under 
the appropriately protective cPAD (which is at least as protective as 
the POD used to assess intermediate-term risk), no further assessment 
of intermediate-term risk is necessary, and EPA relies on the chronic 
dietary risk assessment for evaluating intermediate-term risk for 
difenoconazole.
    5. Aggregate cancer risk for U.S. population. As discussed in Unit 
III.A., the chronic dietary risk assessment is protective of any 
potential cancer effects.
    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, or to infants and children from aggregate 
exposure to difenoconazole residues.

[[Page 82162]]

IV. Other Considerations

A. Analytical Enforcement Methodology

    An adequate enforcement method, gas chromatography with nitrogen/
phosphorus detection (GC/NPD) method AG-575B, is available for the 
determination of residues of difenoconazole per se in/on plant 
commodities. An adequate enforcement method, liquid chromatography 
coupled with tandem mass spectrometry (LC/MS/MS) method REM 147.07b, is 
available for the determination of residues of difenoconazole and CGA-
205375 in livestock commodities.
    The 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; email address: 
residuemethods@epa.gov.

B. International Residue Limits

    In making its tolerance decisions, EPA seeks to harmonize U.S. 
tolerances with international standards whenever possible, consistent 
with U.S. food safety standards and agricultural practices. EPA 
considers the international maximum residue limits (MRLs) established 
by the Codex Alimentarius Commission (Codex), as required by FFDCA 
section 408(b)(4). The Codex Alimentarius is a joint U.N. Food and 
Agriculture Organization/World Health Organization food standards 
program, and it is recognized as an international food safety 
standards-setting organization in trade agreements to which the United 
States is a party. EPA may establish a tolerance that is different from 
a Codex MRL; however, FFDCA section 408(b)(4) requires that EPA explain 
the reasons for departing from the Codex level.
    Codex maximum residue limits (MRLs) for residues of difenoconazole 
have been established. However, since no Codex MRLs have been 
established for residues of difenoconazole in/on oat commodities, rye 
commodities, and wheat hay, harmonization with Codex is not an issue. 
Canadian MRLs for residues of difenoconazole have been established at 
0.01 ppm for oat grain and 0.01 ppm for rye grain and U.S. tolerances 
for oat grain and rye grain are harmonization with these established 
Canadian MRLs. Mexican MRLs for residues of difenoconazole have been 
established; however, no Mexican MRLs have been established for any of 
the cereal grain commodities.

C. Response to Comments

    One comment was received from a private citizen who opposed 
authorization by EPA to allow pesticide use on oats and other 
petitioned-for uses that would result in any pesticide residue on food. 
The Agency has received this same comment on numerous previous 
occasions and rejects it for the reasons previously stated in the 
Federal Register at 70 FR 1349, January 7, 2005.

D. Revisions to Petitioned-For Tolerances

    EPA determined that the proposed tolerance for oat, grain at 0.1 
ppm should be established at 0.01 ppm. This decision was based on the 
translation and re-evaluation of available barley grain data. No 
detectable residues of difenoconazole are expected in/on oat grain from 
the maximum seed treatment use under consideration. Therefore, the 
tolerance should be established at the limit of quantitation (LOQ) of 
the current enforcement method, 0.01 ppm in/on oat grain. EPA increased 
the proposed tolerance in/on oat, forage from 0.1 ppm to 0.15 ppm based 
on the translation and re-evaluation of available wheat forage data; 
using the Organization for Economic Cooperation and Development (OECD) 
MRL calculator, a tolerance of 0.15 ppm is appropriate. For both oat, 
hay and oat, straw EPA decreased the proposed tolerances of 0.1 ppm to 
0.05 ppm based on the translation and re-evaluation of available wheat 
hay and wheat straw data; residues of difenoconazole are not expected 
to exceed the LOQ of the current enforcement method, 0.05 ppm in/on oat 
straw or hay.
    EPA determined that the proposed tolerance for rye, grain at 0.1 
ppm should be established at 0.01 ppm. This decision was based on the 
translation and re-evaluation of available wheat grain data. No 
detectable residues of difenoconazole are expected in/on rye grain; 
therefore, the tolerance should be established at the LOQ of the 
current enforcement method, 0.01 ppm in/on rye grain. Also, the EPA 
recommended tolerance for rye, grain at 0.01 ppm replaces the existing 
difenoconazole import only tolerance for rye, grain 0.1 ppm. EPA 
increased the proposed tolerance for rye, forage from 0.1 ppm to 0.15 
ppm based on the translation and re-evaluation of available wheat 
forage data; using the OECD MRL calculator, a tolerance of 0.15 ppm is 
appropriate. For rye, straw, EPA decreased the proposed tolerance of 
0.1 ppm to 0.05 ppm based on the translation and re-evaluation of 
available wheat straw data; residues of difenoconazole are not expected 
to exceed the LOQ of the current enforcement method, 0.05 ppm in/on rye 
straw.
    For wheat, hay, EPA decreased the proposed tolerance of 0.1 ppm to 
0.05 ppm based on the re-evaluation of available wheat hay data; 
residues of difenoconazole are not expected to exceed the LOQ of the 
current enforcement method, 0.05 ppm in/on wheat hay.

V. Conclusion

    Therefore, tolerances are established for residues of 
difenoconazole, including its metabolites and degradates, in or on the 
commodities listed in the table at the end of this document. Compliance 
with the tolerance levels specified in the table below is to be 
determined by measuring only difenoconazole, 1-[2-[2-chloro-4-(4-
chlorophenoxy)phenyl]-4-methyl-1,3-dioxolan-2-ylmethyl]-1H-1,2,4-
triazole, in or on oat, forage at 0.15 ppm; oat, grain at 0.01 ppm; 
oat, hay at 0.05 ppm; oat, straw at 0.05 ppm; rye, forage at 0.15 ppm; 
rye, grain at 0.01 ppm; rye, straw at 0.05 ppm; and wheat, hay at 0.05 
ppm.

VI. Statutory and Executive Order Reviews

    This final rule establishes tolerances 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 final rule has been 
exempted from review under Executive Order 12866, this final rule is 
not subject to Executive Order 13211, entitled Actions Concerning 
Regulations That Significantly Affect Energy Supply, Distribution, or 
Use (66 FR 28355, May 22, 2001) or Executive Order 13045, entitled 
Protection of Children from Environmental Health Risks and Safety Risks 
(62 FR 19885, April 23, 1997). 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., 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).
    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.

[[Page 82163]]

    This final rule directly regulates growers, food processors, food 
handlers, and food retailers, not States or tribes, nor does this 
action alter the relationships or distribution of power and 
responsibilities established by Congress in the preemption provisions 
of section 408(n)(4) of FFDCA. As such, the Agency has determined that 
this action will not have a substantial direct effect on States or 
tribal governments, on the relationship between the national government 
and the States or tribal governments, or on the distribution of power 
and responsibilities among the various levels of government or between 
the Federal Government and Indian tribes. Thus, the Agency has 
determined that Executive Order 13132, entitled Federalism (64 FR 
43255, August 10, 1999) and Executive Order 13175, entitled 
Consultation and Coordination with Indian Tribal Governments (65 FR 
67249, November 9, 2000) do not apply to this final rule. In addition, 
this final rule does not 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).
    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).

VII. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report 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 21, 2011.
Lois Rossi,
Director, Registration Division, Office of Pesticide Programs.

    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. In Sec.  180.475 the table to paragraph (a) is amended by 
alphabetically adding oat, forage; oat, grain; oat, hay; oat, straw; 
rye, forage; rye, straw; and wheat, hay and by revising the entry for 
rye, grain to read as follows:

Sec.  180.475  Difenoconazole; tolerance for residues.

    (a) * * *
    (1) * * *

------------------------------------------------------------------------
                                                              Parts per
                         Commodity                             million
------------------------------------------------------------------------
 
                                * * * * *
Oat, forage................................................         0.15
Oat, grain.................................................         0.01
Oat, hay...................................................         0.05
Oat, straw.................................................         0.05
 
                                * * * * *
Rye, forage................................................         0.15
Rye, grain.................................................         0.01
Rye, straw.................................................         0.05
 
                                * * * * *
Wheat, hay.................................................         0.05
------------------------------------------------------------------------

* * * * *
[FR Doc. 2011-33482 Filed 12-29-11; 8:45 am]
BILLING CODE 6560-50-P