[Federal Register Volume 76, Number 115 (Wednesday, June 15, 2011)]
[Rules and Regulations]
[Pages 34877-34883]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-14770]

[[Page 34877]]



40 CFR Part 180

[EPA-HQ-OPP-2010-0296; FRL-8876-4]

Difenoconazole; Pesticide Tolerances

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.


SUMMARY: This regulation establishes tolerances for residues of 
difenoconazole in or on aspirated grain fractions; carrot; chickpea; 
fruits, stone, group 12; soybean, hulls; soybean, seed; strawberry; and 
turnip greens. Syngenta Crop Protection, Inc., requested these 
tolerances under the Federal Food, Drug, and Cosmetic Act (FFDCA). This 
regulation also increases the existing tolerances for cattle, liver; 
goat, liver; hog, liver; horse, liver; sheep, liver; and decreases the 
existing tolererance for egg and revises the tolerance expression for 
animal commodities.

DATES: This regulation is effective June 15, 2011. Objections and 
requests for hearings must be received on or before August 15, 2011, 
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-2010-0296. 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 Friday, 
excluding legal holidays. The Docket Facility telephone number is (703) 

FOR FURTHER INFORMATION CONTACT: Rose Mary Kearns, Registration 
Division (7505P), Office of Pesticide Programs, Environmental 
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001; telephone number: (703) 305-5611; e-mail address: 


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 

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://www.gpoaccess.gov/ecfr.

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-2010-0296 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 
August 15, 2011. 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-2010-0296, 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 Tolerance

    In the Federal Register of August 4, 2010 (75 FR 46924) (FRL-8834-
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 
9F7676) by Syngenta Crop Protection, Inc., P.O. Box 18300, Greensboro, 
NC 27419-8300. The petition requested that 40 CFR 180.475 be amended by 
establishing tolerances for residues of the fungicide difenoconazole, 
in or on carrot at 0.45 parts per million (ppm); chickpeas at 0.05 ppm; 
fruits, stone, group 12 at 2.5 ppm; soybean, seed, at 0.2 ppm; soybean, 
aspirated grain fraction at 95 ppm; strawberry at 2.5 ppm; turnip 
greens at 35 ppm; and increasing the existing milk tolerance from 0.01 
to 0.08 ppm. Comments were received on the notice of filing. EPA's 
response to these comments is discussed in Unit IV.C.
    Based upon review of the data supporting the petition, EPA has: 
Increased the proposed tolerance for carrot from 0.45 ppm to 0.50 ppm, 
and for chickpea from 0.05 ppm to 0.08 ppm; decreased the proposed 
soybean, seed tolerance from 0.20 ppm to 0.15 ppm; established a 
tolerance that was not proposed for soybean, hulls at 0.20 ppm; changed 
the proposed tolerance terminology for ``soybean, aspirated grain 
fractions'' to ``aspirated grain fractions;'' revised the tolerance

[[Page 34878]]

expression for animal commodities; increased the existing animal 
tolerances from 0.20 ppm to 0.40 ppm for the livers of cattle, goat, 
hog, horse, and sheep; decreased the existing tolerance for eggs from 
0.10 ppm to 0.02 ppm; not granted the proposed tolerance increase for 
milk from 0.01 to 0.08 ppm. 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) 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 

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 
    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 2,000 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 
effect level (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 and/or quantitative 
susceptibility after exposure to difenoconazole based on 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 these tumors were only induced at doses which were 
considered to be excessively high for carcinogenicity testing. Based on 
excessive toxicity observed at the two highest doses in the study, 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 ``Difenoconazole 
Human Health Risk Assessment for Amended Section 3 Registration to Add 
Uses on Carrots, Chickpeas, Soybeans, Stone Fruits (Group 12), 
Strawberries, Turnip Greens and Golf Course Turf Grass,'' pp. 13-19 in 
docket ID number EPA-HQ-OPP-2010-0296.

B. Toxicological Points of Departure/Levels of Concern

    Once a pesticide's toxicological profile is determined, EPA 
identifies toxicological 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 lowest dose at which adverse effects of 
concern are identified 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 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 chemical name used for 
human risk assessment is shown in the Table of this unit.

[[Page 34879]]

 Table--Summary of Toxicological Doses and Endpoints for Difenoconazole for Use in Human Health Risk Assessment
                                    Point of departure
        Exposure/scenario            and uncertainty/     RfD, PAD, LOC for     Study and toxicological effects
                                      safety  factors      risk assessment
Acute dietary--General population  NOAEL = 25 mg/kg....  Acute RfD = 0.25 mg/ Acute Neurotoxicity study in Rats
 including infants and children.   UFA = 10x...........   kg/day.              LOAEL = 200 mg/kg/day based on
                                   UFH = 10x...........  aPAD = 0.25 mg/kg/    reduced fore-limb grip strength
                                   FQPA SF = 1x........   day.                 in males on day 1.
Chronic dietary--All populations.  NOAEL= 0.96 mg/kg/    Chronic RfD = 0.01   Combined chronic toxicity/
                                    day.                  mg/kg/day.           carcinogenicity (rat; dietary)
                                   UFA = 10x...........  cPAD = 0.01 mg/kg/    LOAEL = 24.1/32.8 mg/kg/day based
                                   UFH = 10x...........   day.                 on cumulative decreases in body-
                                   FQPA SF = 1x........                        weight gains.
Incidental oral short-term--1 to   NOAEL= 1.25 mg/kg/    LOC for MOE = < 100  Reproduction and fertility Study
 30 days.                           day.                                       (rat; dietary) Parental/Offspring
                                   UFA = 10x...........                        LOAEL = 12.5 mg/kg/day based on
                                   UFH = 10x...........                        decreased pup weight in males on
                                   FQPA SF = 1x........                        day 21 and reduction in body-
                                                                               weight gain of F0 females prior
                                                                               to mating, gestation and
Inhalation short- and              Inhalation (or oral)  LOC for MOE = < 100  Reproduction and fertility study
 intermediate-term inhalation and   study NOAEL = 1.25                         (rat; dietary) Parental/Offspring
 oral absorption assumed            mg/kg/day                                  LOAEL = 12.5 mg/kg/day based on
 equivalent.                        inhalation                                 decreased pup weight in males on
                                    absorption rate =                          day 21 and reduction in body-
                                    100%.                                      weight gain of F0 females prior
                                   UFA = 10x...........                        to mating, gestation and
                                   UFH = 10x...........                        lactation.
                                   FQPA SF = 1x........
Cancer, Oral, dermal, inhalation.        Difenoconazole is classified ``Suggestive Evidence of Carcinogenic
                                             Potential'' with a non-linear (MOE) approach for human risk
POD = A data point or an estimated point that is derived from observed dose-response data and used to mark the
  beginning of extrapolation to determine risk associated with lower environmentally relevant human exposures.
  NOAEL = No observed adverse effect level. LOAEL = lowest observed adverse effect level. UF = uncertainty
  factor. UFA = extrapolation from animal to human (interspecies). UFH = potential variation in sensitivity
  among members of the human population (intraspecies). UFL = use of a LOAEL to extrapolate a NOAEL. UFS = use
  of a short-term study for long-term risk assessment. UFDB = to account for the absence of data or other data
  deficiency. FQPA SF = Food Quality Protection Act Safety Factor. PAD = population adjusted dose (a = acute, c
  = chronic). RfD = reference dose. MOE = margin of exposure. LOC = level of concern.

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 
assumed tolerance-level residues, 100 percent crop treated (PCT), and 
the available empirical or dietary exposure evaluation model 
(DEEMTM) (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 
(i.e., anticipated residues) for the majority of commodities, and the 
available empirical or DEEMTM (ver. 7.81) default processing 
factors, and 100 PCT.
    iii. Cancer. EPA determines whether quantitative cancer exposure 
and risk assessments are appropriate for a food-use pesticide based on 
the weight of the evidence from cancer studies and other relevant data. 
Cancer risk is quantified using a linear or nonlinear approach. If 
sufficient information on the carcinogenic mode of action is available, 
a threshold or non-linear approach is used and a cancer RfD is 
calculated based on an earlier noncancer key event. If carcinogenic 
mode of action data are not available, or if the mode of action data 
determines a mutagenic mode of action, a default linear cancer slope 
factor approach is utilized. Based on the data summarized in Unit 
III.A., EPA has concluded that a nonlinear RfD approach is appropriate 
for assessing cancer risk difenoconazole. However, EPA determined that 
a 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 the cancer 
exposure assessment would not exceed the chronic exposure estimate. 
Therefore, the chronic dietary risk estimate will be protective of 
potential cancer risk.
    Cancer risk was assessed using the same exposure estimates as 
discussed in Unit III.C.1.ii.
    iv. Anticipated residue and percent crop treated (PCT) information. 
EPA did not use PCT information in the dietary assessment of 
difenoconazole. EPA used anticipated residues including average field 
trial residues for the majority of commodities, the available empirical 
or DEEMTM (ver. 7.81) default processing factors; and 100 
PCT information in the chronic dietary assessment for difenoconazole.
    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 that the levels in food are not above the levels 
anticipated. For the present action, EPA will issue such data call-ins

[[Page 34880]]

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) and Screening Concentration in Ground Water (SCI-
GROW) models the estimated drinking water concentrations (EDWCs) of 
difenoconazole for surface water are estimated to be 15.8 parts per 
billion (ppb) for acute exposures and 10.4 ppb for chronic exposures. 
For ground water, the EDWCs are estimated to be 0.0128 ppb for both 
acute and chronic exposures.
    Modeled estimates of drinking water concentrations were directly 
entered into the dietary exposure model. The water concentration of 
15.8 ppb and 10.4 ppb were used to assess the contribution to drinking 
water in the acute and chronic dietary risk assessments, respectively.
    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: Application to ornamentals. There is a potential 
for exposure to difenoconazole during mixing, loading, and application 
activities through the dermal and inhalation routes. Difenoconazole 
products are applied by homeowners using handheld spray equipment. 
Exposure duration is considered short-term (1-30 days). In addition, 
residential post-application exposure to treated golf course turf is 
possible for recreational golfers. 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). With triazole type fungicides 
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 site at http://www.epa.gov/pesticides/cumulative.
    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 
complete risk assessment is found in the 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(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 
    2. Prenatal and postnatal sensitivity. EPA determined that the 
available data 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 were manifested as 
decreased in body weight gain and decreased in 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.

[[Page 34881]]

    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 
    i. The toxicity database for difenoconazole is adequate for 
conducting a FQPA risk assessment. At this time, an immunotoxicity 
study is not available. 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. An immunotoxicity 
study is now required as a part of new data requirements in the 40 CFR 
part 158 for conventional pesticide registration; however, the Agency 
does not believe that conducting a functional immunotoxicity study will 
result in a lower POD than that currently in use for overall risk 
assessment, and therefore, a database uncertainty factor (UFDB) 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 in the database, but the effects are transient or 
occur at doses exceeding 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 nor is an additional database uncertainty 
factor needed to account for the lack of this study.
    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 
DEEMTM (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 DEEMTM 
(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 exposure of children 
as well as incidental oral exposure of toddlers is not expected. These 
assessments will not underestimate the exposure and risks posed by 

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 
acute PAD (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. An acute aggregate risk assessment takes into 
account acute exposure estimates from dietary consumption of food and 
drinking water. 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, 1-2 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 49% of the cPAD for 
children 1-2 years old the population group receiving the greatest 
    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 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. Because 
EPA's level of concern for difenoconazole is a MOE of 100 or below, 
these MOEs are not of concern.
    4. Aggregate cancer risk for U.S. population. Based on the 
discussion in Unit III.A and the toxicological endpoints described in 
Unit III.B, EPA has concluded that the cPAD is protective of possible 
cancer effects; therefore, given the results of the chronic risk 
assessment described in this unit, cancer risk resulting from exposure 
to difenoconazole is not of concern.
    5. 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.

IV. Other Considerations

A. Analytical Enforcement Methodology

    An adequate enforcement method, gas chromatography/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 mass 
spectrometry (LC/MS/MS) method REM 147.07b, is available for the 
determination of residues of difenoconazole and CGA-205375 in livestock 
commodities. Adequate confirmatory methods are also available. This is 
the first difenoconazole petition since the new livestock method 
(147.07b) was approved by the Agency and this new method has lower 
level of quantitation than the previous enforcement method.
    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; e-mail address: 

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)

[[Page 34882]]

requires that EPA explain the reasons for departing from the Codex 
    Codex maximum residue levels (MRLs) for residues of difenoconazole 
per se have been established at 0.2 ppm for carrot; 0.02 ppm for soya 
bean (dry); 0.2 ppm for cherries and plums (including prunes); and 0.5 
ppm for nectarines and peaches. Canadian and Mexican MRLs have been 
established for difenoconazole; however, no MRLs have been established 
for the commodities included in the current petition. Codex MRLs for 
residues of difenoconazole and its metabolite CGA-205375, expressed as 
difenoconazole have been established at 0.2 ppm for edible offal 
(mammalian) and 0.01 for eggs. Also, Canadian MRLs have been 
established for difenoconazole at 0.05 ppm for meat byproducts of 
cattle, goats, hogs, and sheep and at 0.05 ppm in eggs. Based on the 
submitted/available magnitude of the residue data, harmonization with 
established Codex MRLs is not possible for carrots, soya bean (dry), 
cherries, plums (including prunes), nectarines, peaches, edible offal 
(mammalian), and eggs because the Codex MRLs are too low, due to 
differences in the use patterns, called Good Agricultural Practices or 
    Harmonization with the established Canadian MRLs for eggs and meat 
byproducts of cattle, goats, hogs, and sheep is not possible due to 
differences in the regulated residue expression.

C. Response to Comments

    One anonymous comment was received on August 7, 2010. This 
commenter opposes the establishment of any numerical tolerance other 
than zero. No information was submitted to support the commenter's 

D. Revisions to Petitioned-For Tolerances

    1. Tolerances for carrot, chickpea, and soybean, seed were 
corrected to use the recommendation from the EPA tolerance spreadsheet 
(January 2008 version).
    2. No tolerance proposal was made for soybean, hulls, which is a 
regulated commodity. A tolerance is being established for this 
commodity, because difenoconazole residues concentrate in this 
    3. Commodity names for proposed tolerances are being corrected to 
be consistent with EPA's standard commodity vocabulary definitions: 
``Chickpeas'' to ``Chickpea;'' ``Soybean, aspirated grain fractions'' 
to ``Aspirated Grain Fractions;'' ``Fruits, stone, group 12'' to 
``Fruit, stone, group 12''.
    4. The animal commodity tolerance expression is being changed 
slightly to express the metabolite CGA 205375 as a difenoconazole 
stoichoimetric equivalent.
    5. There are a number of livestock feedstuffs associated with the 
proposed uses and currently established livestock tolerances were 
reassessed. Due primarily to the significant change in the beef diet 
from the proposed use on soybeans and the residues of difenoconazole 
found in/on soybean aspirated grain fractions, the tolerance levels for 
residues of concern in liver of cattle, goat, hog, horse, and sheep 
need to be increased from 0.20 ppm to 0.40 ppm.
    6. Although there was little change in the poultry diet from the 
proposed new uses, due to the lower level of quantitation from the new 
animal commodity enforcement analytical method (method 147.07b), the 
tolerance level for residues of concern in egg needs to be decreased 
from 0.10 ppm to 0.02 ppm. Furthermore, the existing commodity name for 
``eggs'' is being corrected to ``egg'' consistent with EPA's standard 
commodity vocabulary definition.
    7. The proposed increased tolerance for milk is not needed because 
the calculations for changes in the dietary burden due to the new uses 
indicate no change is needed.

V. Conclusion

    Therefore, tolerances are established for residues of 
difenoconazole, 1-([2-[2-chloro-4-(4-chlorophenoxy)phenyl]-4-methyl-
1,3-dioxolan-2-yl]methyl)-1H-1,2,4-triazole, in or on: Aspirated grain 
fractions at 95 ppm; carrot at 0.50 ppm; chickpea at 0.08 ppm; fruit, 
stone, group 12 at 2.5 ppm; soybean, hulls at 0.20; soybean, seed at 
0.15; strawberry at 2.5 ppm; turnip greens at 35 ppm. The existing 
animal commodity tolerance expression is being revised, and tolerances 
are being increased for liver of cattle/goat/hog/horse/sheep from 0.20 
ppm to 0.40 ppm. The existing egg tolerance is being decreased from 
0.10 ppm to 0.02 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.
    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 

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

[[Page 34883]]

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: June 7, 2011.
Lois Rossi,
Director, Registration Division, Office of Pesticide Programs.

    Therefore, 40 CFR chapter I is amended as follows:


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

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

2. Section 180.475 is amended as follows:
i. In the table to paragraph (a)(1), by alphabetically adding the 
following commodities; and
ii. In paragraph (a)(2), by revising the introductory text and the 
following commodities in the table.
    The amendments read as follows:

Sec.  180.475  Difenoconazole; tolerances for residues.

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

                                                               Parts per
                          Commodity                             million
                                * * * * *
Aspirated grain fractions...................................       95
                                * * * * *
Carrot......................................................        0.50
Chickpea....................................................        0.08
                                * * * * *
Fruits, stone, group 12.....................................        2.5
                                * * * * *
Soybean, hulls..............................................        0.20
Soybean, seed...............................................        0.15
Strawberry..................................................        2.5
Turnip, greens..............................................       35
                                * * * * *

     (2) Tolerances are established for residues of difenoconazole, 
including its metabolites and degradates, in the commodities in the 
table below. Compliance with the tolerance levels specified below is to 
be determined by measuring the sum of difenoconazole, 1-[2-[2-chloro-4-
triazole, and its metabolite, CGA-205375, 1-[2-chloro-4-(4-chloro-
phenoxy)phenyl]-2-[1,2,4]triazol-1-yl-ethanol, calculated as the 
stoichiometric equivalent of difenoconazole, in the following 

                                                               Parts per
                          Commodity                             million
                                * * * * *
Cattle, liver................................................       0.40
                                * * * * *
Egg..........................................................       0.02
                                * * * * *
Goat, liver..................................................       0.40
                                * * * * *
Hog, liver...................................................       0.40
                                * * * * *
Horse, liver.................................................       0.40
                                * * * * *
Sheep, liver.................................................       0.40
                                * * * * *

* * * * *
[FR Doc. 2011-14770 Filed 6-14-11; 8:45 am]