
[Federal Register: May 28, 2010 (Volume 75, Number 103)]
[Rules and Regulations]               
[Page 29908-29914]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr28my10-11]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2009-0279; FRL-8828--6]

 
Prothioconazole; Pesticide Tolerances

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes tolerances for combined residues 
of prothioconazole and prothioconazole-desthio, calculated as parent in 
or on grain, cereal, group 15 (except sweet corn, sorghum, and rice), 
and grain, cereal, forage, fodder and straw, group 16 (except sweet 
corn, sorghum, and rice) and sweet corn. Bayer CropScience requested 
these tolerances under the Federal Food, Drug, and Cosmetic Act 
(FFDCA).

DATES: This regulation is effective May 28, 2010. Objections and 
requests for hearings must be received on or before July 27, 2010, 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-2009-0279. 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) 
305-5805.

FOR FURTHER INFORMATION CONTACT: Tawanda Maignan, Registration Division 
(7505P), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone 
number: (703) 308-8050; e-mail address: maignan.tawanda@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 cite at http://www.gpoaccess.gov/ecfr. To 
access the harmonized test guidelines referenced in this document 
electronically, please go http://www.epa.gov/ocspp and select ``Test 
Methods and Guidelines.''

C. 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-2009-0279 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 
July 27, 2010. 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 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 this copy, identified by docket ID number 
EPA-HQ-OPP-2009-0279, 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

[[Page 29909]]

(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 19, 2009 (74 FR 41898) (FRL-8426-
7), 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 
8F7485) by Bayer CropScience, P.O. Box 12014, 2 T.W. Alexander Drive, 
Research Triangle Park, NC 27709. The petition requested that 40 CFR 
180.626 be amended by establishing tolerances for residues of the 
fungicide prothioconazole, 2-[2-(1-chlorocyclopropyl)-3-(2-
chlorophenyl)-2-hydroxypropyl]-1,2-dihydro-3H-1,2,4-triazole-3-thion, 
in or on grain, cereal, group 15, except sweet corn, sorghum and rice 
at 0.35 parts per million (ppm); forage, cereal, group 16, except sweet 
corn, sorghum and rice at 8.0 ppm; stover, cereal, group 16, except 
sweet corn, sorghum and rice at 10 ppm; hay, cereal, group 16, except 
sweet corn, sorghum and rice at 7.0 ppm; straw, cereal, group 16, 
except sweet corn, sorghum and rice at 5.0 ppm; corn, sweet, forage at 
7.0 ppm; corn, sweet, stover at 8.0 ppm; and corn, sweet, kernel plus 
cob with husks removed at 0.02 ppm. That notice referenced a summary of 
the petition prepared by Bayer CropScience, the registrant, which is 
available in the docket, http://www.regulations.gov. A comment was 
received on the notice of filing. EPA's response to the comment is 
discussed in Unit IV.C.
    Based upon review of the data supporting the petition, EPA has 
established and increased the proposed tolerance of 0.02 ppm for 
combined residues in/on sweet corn to a higher tolerance of 0.04 ppm. 
Further, EPA has modified crop group terminology and established 
tolerances for grain, cereal, group 15, except sweet corn, sorghum, and 
rice at 0.35 ppm; grain, cereal, group 16, except sorghum and rice; 
forage at 8.0 ppm; grain, cereal, group 16, except sorghum and rice; 
stover at 10 ppm; grain, cereal, group 16, except sorghum and rice; hay 
at 7.0 ppm; grain, cereal, group 16, except sorghum and rice; straw at 
5.0 ppm. With the establishment of the above tolerances, EPA has 
revoked the following tolerances: barley, grain; barley, hay; barley, 
straw; wheat, forage; wheat, grain; wheat, hay; and wheat, straw. EPA 
is also not establishing the proposed tolerances for sweet corn forage 
at 7 ppm and sweet corn stover at 8 ppm because the commodities will be 
covered under grain, cereal, group 16; forage and stover. 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 prothioconazole 
including exposure resulting from the tolerances established by this 
action. EPA's assessment of exposures and risks associated with 
prothioconazole 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. Prothioconazole has low acute toxicity by oral, dermal, and 
inhalation routes. It is not a dermal sensitizer, or a skin or eye 
irritant. Prothioconazole's metabolite, prothioconazole-desthio, also 
has low acute toxicity by oral, dermal, and inhalation routes. It is 
not a dermal sensitizer, or a skin irritant, but it is a slight eye 
irritant. The subchronic and chronic studies show that the target 
organs at the lowest observable adverse effects level (LOAEL) include 
the liver, kidney, urinary bladder, thyroid and blood. In addition, the 
chronic studies showed body weight and food consumption changes. 
Prothioconazole and its metabolites may be primary developmental 
toxicants, producing effects including malformations in the conceptus 
at levels equal to or below maternally toxic levels in some studies, 
particularly those studies conducted using prothioconazole-desthio. 
Reproduction studies in the rat with prothioconazole and 
prothioconazole-desthio suggest that these chemicals may not be primary 
reproductive toxicants. Acute and subchronic neurotoxicity studies were 
conducted in the rat using prothioconazole. A developmental 
neurotoxicity study was conducted in the rat using prothioconazole-
desthio.
    The available data show that the prothioconazole-desthio metabolite 
produces toxicity at lower dose levels in subchronic, developmental, 
reproductive, and neurotoxicity studies as compared with 
prothioconazole and the two additional metabolites that were tested.
    The available carcinogenicity and/or chronic studies in the mouse 
and rat, using both prothioconazole and prothioconazole-desthio, show 
no increase in tumor incidence. Therefore, EPA has concluded that 
prothioconazole and its metabolites are not carcinogenic, and are 
classified as ``Not likely to be Carcinogenic to Humans'' according to 
the 2005 Cancer Guidelines.
    Specific information on the studies received and the nature of the 
adverse effects caused by prothioconazole 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.regulations.gov in document ``Prothioconazole. Human Health Risk 
Assessment for Proposed Section 3 Uses on Crop Group 15 and 16 (Cereal 
Grains and Forage, Fodder and Straw of the Cereal Grains Group Except 
Sweet Corn, Sorghum and Rice) and Sweet Corn,'' pages 14 to 17 in 
docket ID number EPA-HQ-OPP-2009-0279.

B. Toxicological Points of Departure and 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

[[Page 29910]]

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 no adverse effects are observed (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 
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 prothioconazole used 
for human risk assessment is shown in the following Table.

    Table--Summary of Toxicological Doses and Endpoints for Prothioconazole for Use in Human Risk Assessment
----------------------------------------------------------------------------------------------------------------
                                        Point of Departure and
          Exposure/Scenario               Uncertainty/Safety     RfD, PAD, LOC for Risk  Study and Toxicological
                                               Factors                 Assessment                Effects
----------------------------------------------------------------------------------------------------------------
Acute dietary                          NOAEL = 2.0milligrams/   Acute RfD = 0.02 mg/kg/  Developmental Toxicity
(Females 13-49 years of age).........   kilograms/day (mg/kg/    day                      Study in Rabbits
                                        day)                    aPAD = 0.02 mg/kg/day..  LOAEL = 10 mg/kg/day
                                       UFA = 10x..............                            based on structural
                                       UFH = 10x..............                            alterations including
                                       FQPA SF = 1x...........                            malformed vertebral
                                                                                          body and ribs,
                                                                                          arthrogryposis, and
                                                                                          multiple
                                                                                          malformations.
----------------------------------------------------------------------------------------------------------------
Chronic dietary                        NOAEL = 1.1 mg/kg/day    Chronic RfD = 0.01 mg/   Chronic/Oncogenicity
(All populations)....................  UFA = 10x..............   kg/day                   Study in Rats
                                       UFH = 10x..............  cPAD = 0.01 mg/kg/day..  LOAEL = 8.0 mg/kg/day
                                       FQPA SF = 1x...........                            based on liver
                                                                                          histopathology
                                                                                          (hepatocellular
                                                                                          vacuolation and fatty
                                                                                          change (single cell,
                                                                                          centrilobular, and
                                                                                          periportal)).
----------------------------------------------------------------------------------------------------------------
UFA = extrapolation from animal to human (interspecies). UFH = potential variation in sensitivity among members
  of the human population (intraspecies). FQPA SF = Food Quality Protection Act Safety Factor. PAD = population
  adjusted dose (a = acute, c = chronic). RfD = reference dose. Loc = level of concern.

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. In evaluating dietary 
exposure to prothioconazole and its metabolites and/or degradates, EPA 
considered exposure under the petitioned-for tolerances as well as all 
existing prothioconazole tolerances in 40 CFR 180.626. EPA assessed 
dietary exposures from prothioconazole 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.
    In estimating acute dietary exposure, EPA used food consumption 
information from the U.S. Department of Agriculture (USDA) 1994-1996 
and 1998 Nationwide Continuing Surveys of Food Intake by Individuals 
(CSFII). As to residue levels in food, EPA conducted a moderately 
refined acute dietary exposure assessment. Average field trial values 
(because all of the crops included in this assessment are blended food 
forms, except sweet corn), empirical processing factors, and livestock 
maximum residues were incorporated into the refined acute assessment. 
The assessment also assumed 100% crop treated (CT). Since no observed 
effects would be attributable to a single dose exposure for the general 
U.S. population, females 13 to 49 years of age was the only population 
subgroup included in the acute assessment.
    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 conducted a 
moderately refined chronic dietary exposure assessment. Empirical 
processing factors, average field trial residues, and livestock 
commodity residues derived from feeding studies and a reasonably 
balanced dietary burden (RBDB) were incorporated into the chronic 
assessment; 100% crop treated was assumed.
    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 non-linear 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 non-cancer 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 
prothioconazole is classified as ``Not Likely to be Carcinogenic to 
Humans.'' Therefore, a dietary exposure assessment for the purpose of 
assessing cancer risk is unnecessary.
    iv. Anticipated residue and percent crop treated (PCT) information. 
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 
as are required by section 408(b)(2)(E) of FFDCA and authorized under 
section

[[Page 29911]]

408(f)(1) of FFDCA. Data will be required to be submitted no later than 
5 years from the date of issuance of these tolerances. Average residues 
and 100 PCT were assumed for all food commodities.
    2. Dietary exposure from drinking water. The Agency used screening 
level water exposure models in the dietary exposure analysis and risk 
assessment for prothioconazole in drinking water. These simulation 
models take into account data on the physical, chemical, and fate/
transport characteristics of prothioconazole. 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 
prothioconazole for the acute dietary risk assessment, the water 
concentration value of 94.7 parts per billion (ppb) was used to assess 
the contribution to drinking water. For the chronic dietary risk 
assessment, the water concentration value of 84.3 ppb was used to 
assess the contribution to drinking water. Modeled estimates of 
drinking water concentrations were directly entered into the dietary 
exposure model.
    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).
    Prothioconazole is not registered for any specific use patterns 
that would result in residential exposure.
    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.''
    Prothioconazole is a member of the triazole-containing class of 
pesticides, often referred to as the triazoles. EPA is not currently 
following a cumulative risk approach based on a common mechanism of 
toxicity for the conazoles. The conazole pesticides, as a whole, tend 
to exhibit carcinogenic, developmental, reproductive, and/or 
neurological effects in mammals. Additionally, all the members of this 
class of compounds are capable of forming, via environmental and 
metabolic activities, 1,2,4-triazole, triazolylalanine and/or 
triazolylacetic acid. These metabolites have also been shown to cause 
developmental, reproductive, and/or neurological effects. That these 
compounds, however, have structural similarities and share some common 
effects does not alone show 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. A number of 
potential events could contribute to the toxicity of conazoles (e.g., 
altered cholesterol levels, stress responses, altered DNA methylation). 
At this time, there is not sufficient evidence to determine whether 
conazoles share common mechanisms of toxicity. Without such 
understanding, there is no basis to make a common mechanism of toxicity 
finding for the diverse range of effects found. Investigations into the 
conazoles are currently being undertaken by the EPA's Office of 
Research and Development. When the results of this research are 
available, the Agency will make a determination of whether there is a 
common mechanism of toxicity and, therefore, a basis for assessing 
cumulative risk. 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.
    To support existing tolerances and to establish new tolerances for 
conazole pesticides, including prothioconazole, EPA conducted human 
health risk assessments for exposure to 1,2 4-triazole, 
triazolylalanine, and triazolylacetic acid resulting from the use of 
all current and pending uses of triazole-containing pesticides (as of 
9/1/05). The risk assessment is a highly conservative, screening-level 
evaluation in terms of hazards associated with the common metabolites 
(e.g., use of maximum combination of uncertainty factors) and potential 
dietary and non-dietary exposures (i.e., high-end estimates of both 
dietary and non-dietary exposures). Acute and chronic aggregate risk 
estimates associated with these compounds are below the Agency's level 
of concern for all durations of exposure and for all population 
subgroups, including those of infants and children. The Agency's risk 
assessment for these common metabolites is available 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(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. There is evidence of 
increased susceptibility following prenatal/or postnatal exposure in:
    i. Rat developmental toxicity studies with prothioconazole as well 
as its prothioconazole-desthio and sulfonic acid K salt metabolites.
    ii. Rabbit developmental toxicity studies with prothioconazole-
desthio.
    iii. A rat developmental neurotoxicity study with prothioconazole-
desthio; and
    iv. Multi-generation reproduction studies in the rat with 
prothioconazole-desthio. Effects include skeletal structural 
abnormalities, such as cleft palate, deviated snout, malocclusion, 
extra ribs, and developmental delays. Available data also show that the 
skeletal effects such as extra ribs are not completely reversible after 
birth in the rat, but persist as development continues.
    Although increased susceptibility was seen in these studies, the 
Agency concluded that there is a low concern and no residual 
uncertainties for prenatal and/or postnatal toxicity effects of 
prothioconazole because:
     Developmental toxicity NOAELs and LOAELs from prenatal 
exposure are well characterized after oral and dermal exposure;
     The off-spring toxicity NOAELs and LOAELs from postnatal 
exposures are well characterized; and
     The NOAEL for the fetal effect, malformed vertebral body 
and ribs, is used for assessing acute risk of females 13 years and 
older and, because it is lower than the NOAELs in other developmental 
studies, is protective of all potential developmental effects.
    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:

[[Page 29912]]

    i. The toxicity database for prothioconazole is considered 
complete, with the exception of required functional immunotoxicity 
testing. The Agency began requiring functional immunotoxicity testing 
of all food and non-food use pesticides on December 26, 2007. Although 
an immunotoxicity study in the mouse is part of the existing 
prothioconazole toxicity database, this study as reported does not 
satisfy the current guideline requirements for an immunotoxicity study 
(OPPTS 870.7800). As such, EPA is requiring that an immunotoxicity 
study be submitted which meets guideline requirements. EPA has 
evaluated the available prothioconazole toxicity database (including 
the non-guideline study in the mouse) to determine whether an 
additional database uncertainty factor is needed to account for 
potential immunotoxicity. In one chronic study in the rat (but not in 
the mouse or dog), blood leukocyte counts were significantly elevated 
at the high dose level (750 mg/kg/day) along with increased thrombocyte 
counts and decreased hemoglobin. However, this finding is made in the 
presence of toxicity to a broad range of organ systems such as the 
liver, urinary bladder, kidney, thyroid, and decreased body weight 
gains. In a chronic dog study, splenic effects (increased spleen weight 
with pigmentation and/or fibrosiderotic plaques) were seen at 40 mg/kg/
day and above, but these effects are not considered to be indicative of 
immunotoxicity, and occurred in the presence of toxicity to the liver, 
kidney, thyroid, and decreased body weights. Furthermore, no signs of 
immunotoxicity, such as changes in leukocyte counts and albumin/
globulin ratio, changes in thymus and spleen weights, or 
histopathological changes in lymphoid tissues, were observed at dose 
levels up to 400 mg/kg/day in the non-guideline immunotoxicity study in 
the mouse. There appears to be no basis for concern for immunotoxicity, 
particularly at the Points of Departure (POD) for prothioconazole and 
its metabolites which, at 2.0 and 1.1 mg/kg/day (Acute and Chronic 
Reference Dose (aRfD and cRfD), respectively) are two orders of 
magnitude lower than the 400 and 750 mg/kg/day dose levels mentioned in 
this Unit. This finding, along with the absence of immunotoxicity 
observed in the subchronic and chronic studies with prothioconazole and 
its metabolites supports the reduction of the FQPA factor to 1X in the 
interim, pending receipt of an acceptable guideline immunotoxicity 
study.
    ii. There is an acceptable battery of neurotoxicity studies 
including a developmental neurotoxicity study. Although offspring 
neurotoxicity was found, characterized by peripheral nerve lesions in 
the developmental neurotoxicity studies on prothioconazole-desthio, the 
increase was seen only in the highest dose group at 105 mg/kg/day, was 
not considered treatment related, and a clear NOAEL was established for 
this study.
    iii. Although increased susceptibility was seen in the 
developmental and reproduction studies, the Agency concluded that there 
is a low concern and no residual uncertainties for prenatal and/or 
postnatal toxicity effects of prothioconazole for the reasons explained 
in Unit III.D.2.
    iv. There are no residual uncertainties identified in the exposure 
databases. The dietary food exposure assessment utilized empirical 
processing factors, 100% crop treated, average crop field trial residue 
levels, and livestock maximum residues. Results from ruminant feeding 
studies and poultry metabolism studies were used to determine the 
maximum residue levels for livestock commodities. The crop field trials 
were performed using maximum application rates and minimum pre-harvest 
intervals. EPA made conservative (protective) assumptions in the ground 
and surface water modeling used to assess exposure to prothioconazole 
in drinking water. These assessments will not underestimate the 
exposure and risks posed by prothioconazole.

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.
    Based on the proposed and existing crop uses for prothioconazole, 
dietary aggregate exposures (i.e., food plus drinking water) are 
anticipated. There are no residential uses for prothioconazole and, 
therefore, no residential exposures are anticipated. Consequently, only 
dietary (food plus drinking water) exposures were aggregated for this 
assessment.
    1. Acute risk. Using the exposure assumptions discussed in this 
unit for acute exposure, the acute dietary exposure from food and water 
to prothioconazole will occupy 38% of the aPAD for females 13 to 49 
years of age, 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 
prothioconazole from food and water will utilize 21% of the cPAD for 
the general U.S. population and 62% of the cPAD for all infants <1 year 
old, the population group receiving the greatest exposure. There are no 
residential uses for prothioconazole.
    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). Because there 
is no residential exposure, prothioconazole is not expected to pose a 
short-term risk.
    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). Because there is no residential exposure, prothioconazole is 
not expected to pose an intermediate-term risk.
    5. Aggregate cancer risk for U.S. population. Based on the lack of 
evidence of carcinogenicity in two adequate rodent carcinogenicity 
studies, prothioconazole is not expected to pose a cancer risk to 
humans.
    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 prothioconazole residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    Adequate liquid chromatography methods with tandem mass 
spectrometry detection (LC/MS/MS) are available to enforce the 
tolerance expression. The method 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

    In making its tolerance decisions, EPA seeks to harmonize U.S. 
tolerances with

[[Page 29913]]

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.
    The Codex has established MRLs for residues of desthio-
prothioconazole in barley at 0.2 ppm (04/2010), and in oats, rye, and 
wheat at 0.05 ppm each and in the fodder (dry) of cereal grains at 4 
ppm and in the straw (dry) of cereal grains at 5 ppm. There are 
currently no established Mexican MRLs for prothioconazole. Canadian 
MRLs have been established for prothioconazole per se in/on several 
commodities, including barley (0.35 ppm), wheat (0.07 ppm), meat 
byproducts of cattle, goats, horses and sheep (0.2 ppm), meat 
byproducts of hogs (0.05 ppm), liver of poultry (0.02 ppm), meat of 
cattle, goats, horses, and sheep (0.02 ppm), and milk (0.02 ppm). 
Harmonization of the proposed tolerances with the existing Codex for 
prothioconazole is not possible at this time because of differences in 
tolerance expression and use patterns. The MRL expression for Codex is 
prothioconazole-desthio and is thus not compatible with the U.S. 
tolerance definition, the sum of prothiocoanzole and prothioconazole-
desthio. Much of the Codex cereal grain supervised field trial data is 
from Europe, where the use pattern is different resulting in lower 
measured residues. The straw numerical value (5 ppm) is matched between 
the U.S. and Codex.
    The tolerance definition for plant commodities in Canada were 
recently changed (02/10/2010) and is now harmonized with the U.S. 
residue definition. The barley tolerance of Canada agrees with the 
recommended U.S. tolerance for cereal grains (except sweet corn, 
sorghum, and rice) of 0.35 ppm. However, the Canadian tolerance for 
wheat is lower (0.07 ppm) than the recommended U.S. group tolerance. 
The 0.07 ppm value is the current U.S. tolerance value for wheat, but 
will be replaced by the cereal grain group tolerance. Canada does not 
routinely establish animal feed commodity tolerances, and therefore 
there are no harmonization issues with forage, stover, hay, and straw.

C. Response to Comments

    One comment was received from an anonymous source objecting to 
establishment of tolerances and stating that the Agency is not 
protecting human health. The response contained no scientific data or 
evidence to rebut the Agency's conclusion that there is a reasonable 
certainty that no harm will result from aggregate exposure to 
prothioconazole, including all anticipated dietary exposures and other 
exposures for which there is reliable information.

D. Revisions to Petitioned-For Tolerances

    Prothioconazole tolerances for crop commodities listed in 40 CFR 
180.626(a)(1) are expressed in terms of the combined residues of the 
fungicide prothioconazole and prothioconazole-desthio, calculated as 
parent. EPA has also revised the tolerance expression to clarify (1) 
that, as provided in section 408(a)(3) of FFDCA, the tolerance covers 
metabolites and degradates of prothioconazole not specifically 
mentioned; and (2) that compliance with the specified tolerance levels 
is to be determined by measuring only the specific compounds mentioned 
in the tolerance expression.
    Tolerances are established for residues of prothioconazole, 2-[2-
(1-chlorocylcopropyl)-3-(2-chlorophenyl)-2-hydroxypropyl]-1,2-dihydro-
3H-1,2,4-triazole-3-thion, including its metabolites and degradates, in 
or on the commodities in the table below. Compliance with the tolerance 
levels specified below is to be determined by measuring only 
prothioconazole and its metabolite prothioconazole-desthio, or [alpha]-
(1-chlorocyclopropyl)-[alpha]-[(2-chlorophenyl)methyl]-1H-1,2,4-
triazole-1-ethanol, calculated as parent in or on the commodity.
    Tolerances are established for residues of prothioconazole, 2-[2-
(1-chlorocylcopropyl)-3-(2-chlorophenyl)-2-hydroxypropyl]-1,2-dihydro-
3H-1,2,4-triazole-3-thion, including its metabolites and degradates, in 
or on the commodities in the table below. Compliance with the tolerance 
levels specified below is to be determined by measuring only 
prothioconazole and its metabolites prothioconazole-desthio, or 
[alpha]-(1-chlorocyclopropyl)-[alpha]-[(2-chlorophenyl)methyl]-1H-
1,2,4-triazole-1-ethanol, and conjugates that can be converted to these 
two compounds by acid hydrolysis, calculated as parent in or on the 
commodity.
    The proposed tolerance of 0.02 ppm for combined residues in/on 
sweet corn K+CWHR should be increased to 0.04 ppm (reflecting the 
combined limit of quantitation of 0.02 ppm each for prothioconazole and 
prothioconazole-desthio).
    The proposed tolerances of 7 ppm for sweet corn forage and 8 ppm 
for sweet corn stover should be removed. These commodities will be 
covered by the tolerance for group 16 grain, cereal, forage and group 
16, cereal, grain, stover, respectively.
    With the establishment of the requested crop group tolerances for 
group 15 and 16, the established tolerances for the following 
commodities are no longer necessary and should be removed: barley, 
grain; barley, hay; barley, straw; wheat, forage; wheat, grain; wheat, 
hay; and wheat, straw.

V. Conclusion

    Therefore, tolerances are established for residues of 
prothioconazole, 2-[2-(1-chlorocylcopropyl)-3-(2-chlorophenyl)-2-
hydroxypropyl]-1,2-dihydro-3H-1,2,4-triazole-3-thion, including its 
metabolites and degradates, in or on grain, cereal, group 15, except 
sweet corn, sorghum, and rice at 0.35 ppm; grain, cereal, group 16, 
except sorghum and rice; forage at 8.0 ppm; grain, cereal, group 16, 
except sorghum and rice; stover at 10 ppm; grain, cereal, group 16, 
except sorghum and rice; hay at 7.0 ppm; grain, cereal, group 16, 
except sorghum and rice; straw at 5.0 ppm.; corn, sweet, kernel plus 
cob with husks removed at 0.04 ppm.
    Further, the EPA is revoking the following eight existing 
tolerances because they are no longer needed as a result of this rule: 
barley, grain; barley, hay; barley, straw; wheat, forage; wheat, grain; 
wheat, hay; and wheat, straw. The EPA is also revising the 
prothioconazole crop and animal tolerance expressions.

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,

[[Page 29914]]

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) (Public Law 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: May 21, 2010.
Daniel J. Rosenblatt,
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. Amend Sec.  180.626 as follows:
    a. Revise the introductory text to paragraph (a)(1).
    b. Remove from the table in paragraph (a)(1) existing entries for 
barley, grain; barley, hay; barley, straw; wheat, forage; wheat, grain; 
wheat, hay; and wheat, straw.
    c. Add alphabetically new commodities to the table in paragraph 
(a)(1).
    d. Revise the introductory text to paragraph (a)(2).
    The added and revised text read as follows:


Sec.  180.626  Prothioconazole; tolerances for residues.

    (a) * * * (1) Tolerances are established for residues of 
prothioconazole, 2-[2-(1-chlorocylcopropyl)-3-(2-chlorophenyl)-2-
hydroxypropyl]-1,2-dihydro-3H-1,2,4-triazole-3-thion, including its 
metabolites and degradates, in or on the commodities in the table 
below. Compliance with the tolerance levels specified below is to be 
determined by measuring only prothioconazole and its metabolite 
prothioconazole-desthio, or [alpha]-(1-chlorocyclopropyl)-[alpha]-[(2-
chlorophenyl)methyl]-1H-1,2,4-triazole-1-ethanol, calculated as parent 
in or on the commodity.

------------------------------------------------------------------------
                      Commodity                        Parts per million
------------------------------------------------------------------------
                                * * * * *
Corn, sweet, kernel plus cob with husks removed......               0.04
                                * * * * *
Grain, cereal, forage, fodder and straw, group 16,                   8.0
 except sorghum, and rice; forage....................
Grain, cereal, forage, fodder and straw, group 16,                   7.0
 except sorghum, and rice; hay.......................
Grain, cereal, forage, fodder and straw, group 16,                    10
 except sorghum, and rice; stover....................
Grain, cereal, forage, fodder and straw, group 16,                   5.0
 except sorghum, and rice; straw.....................
Grain, cereal, group 15, except sweet corn, sorghum,                0.35
 and rice............................................
                                * * * * *
------------------------------------------------------------------------

    (2) Tolerances are established for residues of prothioconazole, 2-
[2-(1-chlorocylcopropyl)-3-(2-chlorophenyl)-2-hydroxypropyl]-1,2-
dihydro-3H-1,2,4-triazole-3-thion, including its metabolites and 
degradates, in or on the commodities in the table below. Compliance 
with the tolerance levels specified below is to be determined by 
measuring only prothioconazole and its metabolites prothioconazole-
desthio, or [alpha]-(1-chlorocyclopropyl)-[alpha]-[(2-
chlorophenyl)methyl]-1H-1,2,4-triazole-1-ethanol, and conjugates that 
can be converted to these two compounds by acid hydrolysis, calculated 
as parent in or on the commodity.
* * * * *

[FR Doc. 2010-12922 Filed 5-27-10 8:45 am]
BILLING CODE 6560-50-S

