Document ID: EPA-HQ-OPP-2005-0312-0004
Agency: epa
Document Type: Rule
Title: Prothioconazole; Pesticide Tolerance
Posted Date: 2007-03-14T04:00Z

[Federal Register: March 14, 2007 (Volume 72, Number 49)]
[Rules and Regulations]               
[Page 11777-11784]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr14mr07-4]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2005-0312; FRL-8113-6]

 
Prothioconazole; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes tolerances for combined residues 
of prothioconazole and prothioconazole-

[[Page 11778]]

desthio calculated as parent in or on barley, grain/hay/straw; grain, 
aspirated grain fractions; pea and bean, dried shelled, except 
soybeans, subgroup 6C; peanut; peanut hay; rapeseed, seed; wheat, 
grain/forage/hay/straw; and for combined residues of prothioconazole, 
prothioconazole-desthio and conjugates that can be converted to these 
two compounds by acid hydrolysis, calculated as parent in or on cattle, 
meat/meat byproducts/fat/milk; poultry, liver; goat, fat/meat/meat 
byproducts; hog, meat byproducts; horse, fat/meat/meat byproducts; 
sheep, fat/meat/meat byproducts. Bayer CropScience requested tolerances 
under the Federal Food, Drug, and Cosmetic Act (FFDCA), as amended by 
the Food Quality Protection Act of 1996 (FQPA).

DATES: This regulation is effective March 14, 2007. Objections and 
requests for hearings must be received on or before May 14, 2007, and 
must be filed in accordance with the instructions provided in 40 CFR 
part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).

ADDRESSES: EPA has established a docket for this action under docket 
identification (ID) number EPA-HQ-OPP-2005-0312. To access the 
electronic docket, go to http://www.regulations.gov, select ``Advanced 

Search,'' then ``Docket Search.'' Insert the docket ID number where 
indicated and select the ``Submit'' button. Follow the instructions on 
the regulations.gov website to view the docket index or access 
available documents. All documents in the docket are listed in the 
docket index available in 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: Tony Kish, Registration Division 
(7505P), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone 
number: (703) 308-9443; e-mail address: kish.tony@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

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

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

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

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

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

C. Can I File an Objection or Hearing Request?

    Under section 408(g) of FFDCA, as amended by FQPA, any person may 
file an objection to any aspect of this regulation and may also request 
a hearing on those objections. The EPA procedural regulations which 
govern the submission of objections and requests for hearings appear in 
40 CFR part 178. You must file your objection or request a hearing on 
this regulation in accordance with the instructions provided in 40 CFR 
part 178. To ensure proper receipt by EPA, you must identify docket ID 
number EPA-HQ-OPP-2005-0312 in the subject line on the first page of 
your submission. All requests must be in writing, and must be mailed or 
delivered to the Hearing Clerk on or before May 14, 2007.
    In addition to filing an objection or hearing request with the 
Hearing Clerk as described in 40 CFR part 178, please submit a copy of 
the filing that does not contain any CBI for inclusion in the public 
docket that is described in ADDRESSES. Information not marked 
confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA 
without prior notice. Submit your copies, identified by docket ID 
number EPA-HQ-OPP-2005-0312, 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'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. Background and Statutory Findings

    In the Federal Register of November 30, 2005 (70 FR 71831) (FRL-
7747-6), 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 
4F6830) by Bayer CropScience, 2 T.W. Alexander Dr., Research Triangle 
Park, NC 27709. The petition requested that 40 CFR part 180 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-thione, in or on barley, 
grain at 0.2 parts per million (ppm); barley, hay at 7.0 ppm; barley, 
straw at 2.0 ppm; barley, pearled at 0.2 ppm; barley, bran at 0.4 ppm; 
black mustard, seed at

[[Page 11779]]

0.1 ppm; borage, seed at 0.1 ppm; canola, seed at 0.1 ppm; crambe, seed 
at 0.1 ppm; field mustard, seed at 0.1 ppm; flax, seed at 0.1 ppm; 
grain, aspirated fractions at 13.0 ppm; Indian mustard, seed at 0.1 
ppm; Indian rapeseed 0.1 ppm; pea and bean, dried shelled (except 
soybeans) at 0.8; peanut, nutmeat at 0.02 ppm; peanut, hay at 5.0 ppm; 
peanut, meal at 0.3 ppm; rapeseed, seed at 0.1 ppm; rice, grain at 0.25 
ppm; rice, straw at 1.5 ppm; rice, hulls at 1.0 ppm; wheat, grain at 
0.06 ppm; wheat, bran at 1.5 ppm; wheat, forage at 7.0 ppm; wheat, germ 
at 0.15 ppm; wheat, hay at 4.0 ppm; wheat, straw at 2.3 ppm and for 
combined residues of prothioconazole, its desthio and 4-hydroxy 
metabolites, and conjugates of each in cattle, meat at 0.01 ppm; 
cattle, meat byproducts at 1.2 ppm; cattle, fat at 0.1 ppm; and milk at 
0.006 ppm. That notice included a summary of the petition prepared by 
Bayer CropScience, the registrant. Comments were received on the notice 
of filing. EPA's response to these comments is discussed in Unit IV.C.
    For the reasons stated in Unit V., EPA is not establishing at this 
time the following petitioned-for tolerances: Rice; black mustard; 
borage; flax; Indian mustard; barley, pearled barley; barley, bran; 
canola; crambe; field mustard; Indian rapeseed; peanut, meal; wheat, 
bran; and wheat, germ.
    Section 408(b)(2)(A)(i) of FFDCA allows EPA to establish a 
tolerance (the legal limit for a pesticide chemical residue in or on a 
food) only if EPA determines that the tolerance is ``safe.'' Section 
408(b)(2)(A)(ii) of FFDCA defines ``safe'' to mean that ``there is a 
reasonable certainty that no harm will result from aggregate exposure 
to the pesticide chemical residue, including all anticipated dietary 
exposures and all other exposures for which there is reliable 
information.'' This includes exposure through drinking water and in 
residential settings, but does not include occupational exposure. 
Section 408(b)(2)(C) of FFDCA requires EPA to give special 
consideration to exposure of infants and children to the pesticide 
chemical residue in establishing a tolerance and to ``ensure that there 
is a reasonable certainty that no harm will result to infants and 
children from aggregate exposure to the pesticide chemical 
residue....''
    EPA performs a number of analyses to determine the risks from 
aggregate exposure to pesticide residues. For further discussion of the 
regulatory requirements of section 408 of FFDCA and a complete 
description of the risk assessment process, see http://www.epa.gov/oppfead1/trac/science
.

III. Aggregate Risk Assessment and Determination of Safety

    Consistent with section 408(b)(2)(D) of FFDCA, EPA has reviewed the 
available scientific data and other relevant information in support of 
this action. EPA has sufficient data to assess the hazards of and to 
make a determination on aggregate exposure, consistent with section 
408(b)(2) of FFDCA, for a tolerance for combined residues of 
prothioconazole and prothioconazole-desthio, calculated as parent in or 
on barley, grain at 0.35 ppm; barley, hay at 7.0 ppm; barley, straw at 
4.0 ppm; grain, aspirated grain fractions at 11.0 ppm; pea and bean, 
dried shelled, except soybeans, subgroup 6C at 0.9; peanut at 0.02 ppm; 
peanut, hay at 6.0 ppm; rapeseed, seed at 0.15 ppm; wheat, grain at 
0.07 ppm; wheat, forage at 6.0 ppm; wheat, hay at 4.5 ppm; wheat, straw 
at 5.0 ppm and for combined residues of prothioconazole, 
prothioconazole-desthio, and conjugates that can be converted to these 
two compounds by acid hydrolysis, calculated as parent in or on cattle, 
meat at 0.02 ppm; cattle, meat byproducts at 0.2 ppm; cattle, fat at 
0.1 ppm; goat, fat at 0.1 ppm; goat, meat at 0.02 ppm; goat, meat 
byproducts at 0.2 ppm; hog, meat byproducts at 0.05 ppm; horse, fat at 
0.1 ppm; horse, meat at 0.02 ppm; horse, meat byproducts at 0.2 ppm; 
milk at 0.02 ppm; poultry, liver at 0.02 ppm; sheep, fat at 0.1 ppm; 
sheep, meat at 0.02 ppm and sheep, meat byproducts at 0.2 ppm.
    EPA's assessment of exposures and risks associated with 
establishing the tolerance follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its 
validity, completeness, and reliability as well as the relationship of 
the results of the studies to human risk. EPA has also considered 
available information concerning the variability of the sensitivities 
of major identifiable subgroups of consumers, including infants and 
children. Specific information on the studies received and the nature 
of the toxic 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
.

B. Toxicological Endpoints

    For hazards that have a threshold below which there is no 
appreciable risk, the dose at which no adverse effects are observed 
(the NOAEL) from the toxicology study identified as appropriate for use 
in risk assessment is used to estimate the toxicological level of 
concern (LOC). However, the lowest dose at which adverse effects of 
concern are identified (the LOAEL) is sometimes used for risk 
assessment if no NOAEL was achieved in the toxicology study selected. 
An uncertainty factor (UF) is applied to reflect uncertainties inherent 
in the extrapolation from laboratory animal data to humans and in the 
variations in sensitivity among members of the human population as well 
as other unknowns.
    The linear default risk methodology (Q*) is the primary method 
currently used by the Agency to quantify non-threshold hazards such as 
cancer. The Q* approach assumes that any amount of exposure will lead 
to some degree of cancer risk, and estimates risk in terms of the 
probability of occurrence of additional cancer cases. More information 
can be found on the general principles EPA uses in risk 
characterization at:
    1. http://www.epa.gov/oppfead1/trac/science    2. http://www.epa.gov/pesticides/factsheets/riskassess.htm.

.htm.

    Both prothioconazole and prothioconazole-desthio have low acute 
toxicities by oral, dermal, and inhalation routes. Neither compound is 
a dermal sensitizer, nor a skin or eye irritant.
    Subchronic toxicity studies show that the target organs at the 
LOAEL include the liver, kidney, urinary bladder, thyroid, and blood. 
NOAEL/LOAEL values across the family of chemicals (i.e., 
prothioconazole, and metabolites prothioconazole-desthio, and 
prothioconazole sulfonic acid potassium salt) in the toxicity database 
indicate that prothioconazole-desthio is a more toxic chemical.
    The profile of chronic toxicity is similar to that of subchronic 
toxicity, and also includes body weight and food consumption changes, 
and toxicity to the lymphatic and gastrointestintal (GI) systems. The 
relative potency of prothioconazole-desthio is greater than 
prothioconazole.
    The data from developmental toxicity studies indicate that 
prothioconazole and the three metabolites evaluated (i.e., 
prothioconazole-desthio, prothioconazole sulfonic acid potassium salt, 
and prothioconazole-deschloro) variously produce prenatal developmental 
effects at levels equal to or below maternally toxic levels. 
Prothioconazole-desthio is a developmental neurotoxicant,

[[Page 11780]]

producing changes in brain morphometrics and increases in the 
occurrence of peripheral nerve lesions in the neonate. A NOAEL was not 
determined, since these observations were looked for only at the high 
dose level. Prothioconazole-desthio is the most toxic orally or 
dermally, with LOAELs significantly below that of the other chemicals.
    In reproduction studies in the rat, conducted using prothioconazole 
and prothioconazole-desthio, reproductive and offspring toxicities are 
observed only in the presence of parental toxicity. The nature of 
parental toxicity is similar to what was observed in the subchronic 
studies, such as body weight and food consumption changes, liver 
effects, etc. Reproductive effects include decreases in reproductive 
indices such as those that indicate pup survival and growth. Offspring 
toxicity is manifested by decreased pup weights and malformations such 
as cleft palate. The data show that prothioconazole-desthio is more 
toxic by an order of magnitude.
    Acute and subchronic neurotoxicity studies were conducted in the 
rat using prothioconazole. The acute neurotoxicity study produced 
reduced motor and locomotor activity at a relatively high dose level, 
while no neurotoxicity was observed in the subchronic neurotoxicity 
study. As mentioned in the discussion of developmental toxicity, a 
developmental neurotoxicity study was conducted in the rat using 
prothioconazole-desthio, and neurotoxic effects were at the high dose 
level only were included in the report. Judging from these three 
neurotoxicity studies, prothioconazole-desthio is the more potent 
neurotoxicant, which is consistent with its relative potency in other 
areas of toxicity.
    A battery of mutagenicity studies was conducted using both 
prothioconazole and its desthio metabolite. In addition, 
carcinogenicity studies were conducted in rats and mice using these two 
chemicals. The available data indicate that neither of these compounds 
is mutagenic or carcinogenic in the species tested, which mitigates 
against concern for carcinogenicity in humans.
    A summary of the toxicological endpoints for prothioconazole used 
for human risk assessment is shown in Table 1 of this unit:

   Table 1.--Summary of Toxicological Dose and Endpoints for Prothioconazole for Use in Human Risk Assessment
----------------------------------------------------------------------------------------------------------------
                                          Dose used in risk
                                             assessment,        FQPA safety factor (SF)
          Exposure/scenario                interspecies and       and level of concern   Study and toxicological
                                         intraspecies and any     for risk assessment            effects
                                            traditional UF
----------------------------------------------------------------------------------------------------------------
Acute dietary                          NOAEL = 2.0 milligram/   FQPA SF = 10X            Developmental Toxicity
(Females 13-49 years of age).........   kilogram/day (mg/kg/    acute population          study in rabbits
                                        day)                     adjusted dose (aPAD) =  LOAEL = 10 mg/kg/day
                                       UF = 100 X acute          acute RfD/Special FQPA   based on structural
                                        reference dose (RfD) =   SF = 0.002 mg/kg/day.    alterations including
                                        0.002 mg/kg/day.                                  malformed vertebral
                                                                                          body and ribs,
                                                                                          arthrogryposis, and
                                                                                          multiple malformations
----------------------------------------------------------------------------------------------------------------
Chronic dietary                        NOAEL= 1.1 mg/kg/day     FQPA SF = 10X            Chronic/Oncogenicity
(All populations)....................  UF = 100 X chronic RfD   chronic population        study in rats
                                        = 0.001 mg/kg/day.       adjusted dose (cPAD) =  LOAEL = 8.0 mg/kg/day
                                                                 chronic RfD/FQPA SF =    based on liver
                                                                 0.001 mg/kg/day.         histopathology
                                                                                          (hepatocellular
                                                                                          vacuolation and fatty
                                                                                          change (single cell,
                                                                                          centrilobular, and
                                                                                          periportal))
----------------------------------------------------------------------------------------------------------------
Cancer                                  Classification: ``Not likely to be Carcinogenic to Humans'' based on the
(Oral, dermal, inhalation)...........         absence of significant tumor increases in two adequate rodent
                                                                carcinogenicity studies.
----------------------------------------------------------------------------------------------------------------
Note: The toxicity endpoints for prothioconazole-desthio were used for the prothioconazole risk assessment
  because they were slightly more conservative than those for prothioconazole per se.

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. Tolerances have not 
been previously established for the combined residues of 
prothioconazole and prothioconazole-desthio, calculated as parent, in 
or on a variety of raw agricultural commodities and combined residues 
of prothioconazole and prothioconazole-desthio and conjugates that can 
be converted to these two compounds by acid hydrolysis, calculated as 
parent, in or on milk and edible animal products. Risk assessments were 
conducted by EPA to assess 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 conducting the acute dietary exposure assessment EPA used the 
Dietary Exposure Evaluation Model software with the Food Commodity 
Intake Database (DEEM-FCID\TM\, version 2.03), which incorporates food 
consumption data as reported by respondents in the U.S. Department of 
Agriculture (USDA) 1994-1996 and 1998 Nationwide Continuing Surveys of 
Food Intake by Individuals (CSFII), and accumulated exposure to the 
chemical for each commodity. The following assumptions were made for 
the acute exposure assessments: A moderately refined acute dietary 
exposure assessment was conducted for prothioconazole. Empirical 
processing factors (PFs) and livestock maximum residues were 
incorporated, and 100 percent crop treated (PCT) was assumed for the 
acute assessment. Average residue levels were also used, since all of 
the plant commodities included in this assessment are blended food 
forms.
    ii. Chronic exposure. In conducting the chronic dietary exposure 
assessment EPA used DEEM-FCID\TM\, version 2.03, which incorporates 
food consumption data as reported by respondents in the USDA 1994-1996 
and 1998 CSFII, and accumulated exposure to the chemical for each 
commodity. The following assumptions were made for the chronic exposure 
assessments: A moderately refined chronic dietary exposure

[[Page 11781]]

assessment was performed. Empirical PFs, average residues, and 
livestock maximum residues were incorporated into the chronic 
assessment and 100 PCT was assumed.
    iii. Cancer. The Agency classified prothioconazole and/or its 
metabolites as ``Not likely to be Carcinogenic to Humans'' according to 
the 2005 Cancer Guidelines, based on available studies in the mouse and 
rat that showed no increase in tumor incidence. Accordingly, no 
exposure assessment is necessary for assessing cancer risk.
    iv. Anticipated residue and PCT information. For assessment of 
acute dietary risk, empirical PFs and livestock maximum residues were 
incorporated, and 100 PCT was assumed for the acute assessment. Average 
residue levels were also used, since all of the plant commodities 
included in this assessment are blended food forms. Likewise for the 
assessment of chronic dietary risk, empirical PFs, average residues, 
and livestock maximum residues were incorporated into the chronic 
assessment and 100 PCT was also assumed.
    2. Dietary exposure from drinking water. The Agency lacks 
sufficient monitoring exposure data to complete a comprehensive dietary 
exposure analysis and risk assessment for prothioconazole in drinking 
water. Because the Agency does not have comprehensive monitoring data, 
drinking water concentration estimates are made by reliance on 
simulation or modeling taking into account data on the physical 
characteristics of 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 Groundwater (SCI-
GROW) models, the estimated drinking water concentrations (EDWCs) of 
prothioconazole for acute exposures are estimated to be 22 parts per 
billion (ppb) for surface water. The EDWCs for chronic exposures are 
estimated to be 11 ppb for surface water. EPA used the EDWCs for 
surface water in assessing the risk from prothioconazole because the 
EWDCs for ground water are minimal in comparison to surface water.
    3. From non-dietary exposure. The term ``residential exposure'' is 
used in this document to refer to non-occupational, non-dietary 
exposure (e.g., for lawn and garden pest control, indoor pest control, 
termiticides, and flea and tick control on pets).
    Prothioconazole is not registered for use on any sites 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. 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. In conazoles, however, a variable pattern of 
toxicological responses is found. Some are hepatotoxic and 
hepatocarcinogenic in mice. Some induce thyroid tumors in rats. Some 
induce developmental, reproductive, and neurological effects in 
rodents. Furthermore, the conazoles produce a diverse range of 
biochemical events including altered cholesterol levels, stress 
responses, and altered DNA methylation. It is not clearly understood 
whether these biochemical events are directly connected to their 
toxicological outcomes. Thus, there is currently no evidence to 
indicate that conazoles share common mechanisms of toxicity and EPA is 
not following a cumulative risk approach based on a common mechanism of 
toxicity for the conazoles. For information regarding EPA's procedures 
for cumulating effects from substances found to have a common mechanism 
of toxicity, see EPA's website at http://www.epa.gov/pesticides/cumulative
.

    Prothioconazole 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 prothioconazole, 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 UFs) 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 SF for the protection of infants and children. The assessment 
includes evaluations of risks for various subgroups, including those 
comprised of infants and children. The Agency's complete risk 
assessment is found in the propiconazole reregistration docket at 
http://www.regulations.gov, docket ID number EPA-HQ-OPP-2005-0497.

D. Safety Factor for Infants and Children

    1. In general. Section 408 of FFDCA provides that EPA shall apply 
an additional tenfold margin of safety for infants and children in the 
case of threshold effects to account for prenatal and postnatal 
toxicity and the completeness of the database on toxicity and exposure 
unless EPA determines based on reliable data that a different margin of 
safety will be safe for infants and children. Margins of safety are 
incorporated into EPA risk assessments either directly through use of a 
MOE analysis or through using uncertainty (safety) factors in 
calculating a dose level that poses no appreciable risk to humans. In 
applying this provision, EPA either retains the default value of 10X 
when reliable data do not support the choice of a different factor, or, 
if reliable data are available, EPA uses a different additional SF 
value based on the use of traditional UFs and/or special FQPA SFs, as 
appropriate.
    2. Prenatal and postnatal sensitivity--i. Prenatal. Available 
evidence from rat developmental toxicity studies with prothioconazole 
(oral) and its desthio (oral and dermal) and sufonic acid K salt (oral) 
metabolites, rabbit developmental with desthio metabolite (oral), and 
rat developmental neurotoxicity with desthio metabolite (oral), as well 
as a multi-generation reproduction study with the desthio metabolite, 
indicate that there is concern for prenatal toxicity. Effects include 
skeletal structural abnormalities, such as cleft palate, deviated 
snout, malocclusion, and extra ribs; developmental delays; other 
effects include changes in brain morphometry, peripheral nerve lesions, 
and death.
    ii. Postnatal. 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. Data from the developmental 
neurotoxicity study also show that brain morphometry is

[[Page 11782]]

abnormal postnatally, and there is an increased incidence of lesions of 
the peripheral nerves postnatally.
    3. Conclusion. The toxicity database for prothioconazole (and its 
metabolites) is adequate for endpoint selection for exposure risk 
assessment scenarios and for FQPA evaluation, with the exception of 
missing data on brain morphometry at lower does from the developmental 
neurotoxicity study. Effects are seen in the 2-generation reproduction 
studies in rats; developmental studies in rats and rabbits; and a 
developmental neurotoxicity study in rats which suggest that pups are 
more susceptible: Pup effects were seen at levels below the LOAELs for 
maternal toxicity and, in general, were of comparable or greater 
severity compared to the effects observed in adults. Additionally, 
there is uncertainty concerning the LOAEL/NOAEL for developmental 
effects seen in the developmental neurotoxicity study in rats (abnormal 
brain morphometry at high dose) due to a lack of information on brain 
morphometry at lower doses. Given that both quantitative and 
qualitative sensitivity was observed in pups in several studies and in 
more than one species and in at least one of these studies there is 
uncertainty concerning identification of the LOAEL/NOAEL for 
developmental effects, the additional 10X factor for the protection of 
infants and children is being retained.

E. Aggregate Risks and Determination of Safety

    To assess aggregate risk, drinking water estimates were 
incorporated directly into the dietary analysis, rather than using 
back-calculated drinking water levels of comparison (DWLOCs). To better 
evaluate aggregate risk associated with exposure through food and 
drinking water, EPA is no longer comparing EDWCs generated by water 
quality models with DWLOCs. Instead, EPA is now directly incorporating 
the actual water quality model output concentrations into the risk 
assessment. This method of incorporating water concentration into our 
aggregate assessments relies on actual CSFII-reported drinking water 
consumptions and more appropriately reflects the full distribution of 
drinking water concentrations.
    1. Acute risk. Using the exposure assumptions discussed in this 
unit for acute exposure, the acute dietary exposure from food to 
prothioconazole will occupy 11% of the aPAD for females 13 years and 
older, the only population subgroup of concern. In addition, there is 
potential for acute dietary exposure to prothioconazole in drinking 
water. The acute dietary exposure from food plus water to 
prothioconazole will occupy 60% of the aPAD.
    2. Chronic risk. Using the exposure assumptions described in this 
unit for chronic exposure, EPA has concluded that exposure to 
prothioconazole from food will utilize 12% of the cPAD for the U.S. 
population, 17% of the cPAD for all infants (<  1 year old), and 48% of 
the cPAD for children 1-2 years old, the subpopulation at greatest 
exposure. There are no residential uses for prothioconazole that result 
in chronic residential exposure to prothioconazole. In addition, there 
is potential for chronic dietary exposure to prothioconazole in 
drinking water. The chronic dietary exposure for food plus water will 
occupy 86% of the cPAD for all infants (<  1 year old). All other 
population subgroups are lower.
    3. Short-term risk. Short-term aggregate exposure takes into 
account residential exposure plus chronic exposure to food and water 
(considered to be a background exposure level).
    Prothioconazole is not registered for use on any sites that would 
result in residential exposure. Therefore, the aggregate risk is the 
sum of the risk from food and water, which do not exceed the Agency's 
level of concern.
    4. Intermediate-term risk. Intermediate-term aggregate exposure 
takes into account residential exposure plus chronic exposure to food 
and water (considered to be a background exposure level).
    Prothioconazole is not registered for use on any sites that would 
result in residential exposure. Therefore, the aggregate risk is the 
sum of the risk from food and water, which do not exceed the Agency's 
level of concern.
    5. Aggregate cancer risk for U.S. population. The available 
toxicology studies in the mouse and rat showed no increase in tumor 
incidence, and therefore the Agency concluded that prothioconazole or 
its metabolites are not carcinogenic, and classified ``Not Likely to be 
Carcinogenic to Humans'' according to the 2005 Cancer Guidelines. 
Therefore, prothioconazole is not expected to pose a cancer risk.
    6. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
to the general population, and to infants and children from aggregate 
exposure to prothioconazole residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    Adequate enforcement methodologies high performance liquid 
chromatography/tandem mass spectrometry (HPLC-MS/MS) and liquid 
chromatography (with electrospray ionization) and tandem mass 
spectrometry (LC-MS/MS)) is 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

    There are currently no U.S., Canadian, Mexican, or international 
Codex tolerances established for prothioconazole. There are no maximum 
residue limits (MRLs) established for prothioconazole in Codex or in 
Mexico. Maximum residue limits have been established in Canada as a 
result of this Joint Review.

C. Response to Comments

    A private citizen responded to PP 4F6830. Comments were received on 
November 30, 2005, objecting to sale and use of this product. The 
comments further stated that there are not enough long-term testing, 
short-term testing is useless and unreliable and that research is not 
exhaustive enough to support use.
    The Agency response is as follows: The Agency considers the 
database for prothioconazole to be complete and adequate for exposure 
risk assessment, including several long-term studies. The commenter 
submitted no scientific information to support the claims.
    These comments, as well as related comments regarding animal 
testing, have been responded to by the Agency on several occasions. For 
example, 70 FR 1349 (January 7, 2005) (FRL-7691-4) and 69 FR 63083 
(October 29, 2004) (FRL-7681-9).

V. Conclusion

    Therefore, tolerances are established for combined residues of 
prothioconazole, 2-[2-(1-chlorocyclopropyl)-3-(2-chlorophenyl)-2-
hydroxypropyl]-1,2-dihydro-3H-1,2,4-triazole-3-thione, and 
prothioconazole-desthio, [alpha]-(1-chlorocyclopropyl)-[alpha]-[(2-
chlorophenyl)methyl]-1H-1,2,4-triazole-1-ethanol, calculated as parent 
in or on barley, grain at 0.35 ppm; barley, hay at 7.0 ppm; barley, 
straw at 4.0 ppm; grain, aspirated grain fractions at 11.0 ppm; pea and 
bean, dried shelled, except soybeans, subgroup 6C at 0.9; peanut at 
0.02 ppm; peanut, hay at 6.0 ppm; rapeseed, seed at 0.15 ppm; wheat, 
grain at 0.07 ppm; wheat, forage at 6.0 ppm; wheat, hay at 4.5 ppm; 
wheat, straw at 5.0 ppm and for combined residues of prothioconazole, 
2-[2-(1-

[[Page 11783]]

chlorocyclopropyl)-3-(2-chlorophenyl)-2-hydroxypropyl]-1,2-dihydro-3H-
1,2,4-triazole-3-thione, and prothioconazole-desthio, [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 cattle, meat at 0.02 
ppm; cattle, meat byproducts at 0.2 ppm; cattle, fat at 0.1 ppm; goat, 
fat at 0.1 ppm; goat, meat at 0.02 ppm; goat, meat byproducts at 0.2 
ppm; hog, meat byproducts at 0.05 ppm; horse, fat at 0.1 ppm, horse, 
meat at 0.02 ppm; horse, meat byproducts at 0.2 ppm; milk at 0.02 ppm; 
poultry, liver at 0.02 ppm; sheep, fat at 0.1 ppm; sheep, meat at 0.2 
ppm and sheet, meat byproducts at 0.2 ppm.
    Using upper bound residues for water derived from the proposed use 
in rice, acute dietary estimates exceeded the Agency's level of concern 
for food plus water. Further data is needed to resolve uncertainties 
regarding residues of prothioconazole in rice application. Therefore, a 
tolerance for rice is not established at this time.
    Additional crop field trial data are needed to support tolerances 
for black mustard, borage, flax and Indian mustard. Tolerances for 
these commodities are not established at this time.
    Separate tolerances are not needed for barley, pearled barley; 
barley, bran; peanut, meal; wheat, bran; and wheat, germ. As per 40 CFR 
180.1(h), the tolerance for rapeseed will cover the following 
commodities: Canola seed, crambe seed, field mustard seed, and Indian 
rapeseed.

VI. Statutory and Executive Order Reviews

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

VII. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., 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: March 2, 2007.
James Jones,
Director, 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 ollows:

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

0
2. Section 180.626 is added to subpart C to read as follows:

Sec.  180.626  Prothioconazole; tolerances for residues.

    (a) General. (1) Tolerances are established for combined residues 
of the fungicide prothioconazole, 2-[2-(1-chlorocyclopropyl)-3-(2-
chlorophenyl)-

[[Page 11784]]

2-hydroxypropyl]-1,2-dihydro-3H-1,2,4-triazole-3-thione, and 
prothioconazole-desthio, [alpha]-(1-chlorocyclopropyl)-[alpha]-[(2-
chlorophenyl)methyl]-1H-1,2,4-triazole-1-ethanol, calculated as parent 
in or on the following commodities:

----------------------------------------------------------------------------------------------------------------
                       Commodity                                            Parts per million
----------------------------------------------------------------------------------------------------------------
Barley, grain.........................................                                                      0.35
Barley, hay...........................................                                                       7.0
Barley, straw.........................................                                                       4.0
Grain, aspirated grain fractions......................                                                        11
Pea and bean, dried shelled, except soybean, subgroup                                                        0.9
 6C...................................................
Peanut................................................                                                      0.02
Peanut, hay...........................................                                                       6.0
Rapeseed, seed........................................                                                      0.15
Wheat, forage.........................................                                                       6.0
Wheat, grain..........................................                                                      0.07
Wheat, hay............................................                                                       4.5
Wheat, straw..........................................                                                       5.0
----------------------------------------------------------------------------------------------------------------

    (2) Tolerances are established for combined residues of the 
fungicide prothioconazole, 2-[2-(1-chlorocyclopropyl)-3-(2-
chlorophenyl)-2-hydroxypropyl]-1,2-dihydro-3H-1,2,4-triazole-3-thione, 
and prothioconazole-desthio, [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 following commodities:

----------------------------------------------------------------------------------------------------------------
                       Commodity                                            Parts per million
----------------------------------------------------------------------------------------------------------------
Cattle, fat...........................................                                                       0.1
Cattle, meat..........................................                                                      0.02
Cattle, meat byproducts...............................                                                       0.2
Goat, fat.............................................                                                       0.1
Goat, meat............................................                                                      0.02
Goat, meat byproducts.................................                                                       0.2
Hog, meat byproducts..................................                                                      0.05
Horse, fat............................................                                                       0.1
Horse, meat...........................................                                                      0.02
Horse, meat byproducts................................                                                       0.2
Milk..................................................                                                      0.02
Poultry liver.........................................                                                      0.02
Sheep, fat............................................                                                       0.1
Sheep, meat...........................................                                                      0.02
Sheep, meat byproducts................................                                                       0.2
----------------------------------------------------------------------------------------------------------------

    (b) Section 18 emergency exemptions. [Reserved]
    (c) Tolerances with regional registrations. [Reserved]
    (d) Indirect or inadvertent residues. [Reserved]

[FR Doc. E7-4405 Filed 3-13-07; 8:45 am]

BILLING CODE 6560-50-S