Document ID: EPA-HQ-OPP-2006-1026-0005
Agency: epa
Document Type: Rule
Title: Pyrasulfotole; Pesticide Tolerance
Posted Date: 2007-08-15T04:00Z

[Federal Register: August 15, 2007 (Volume 72, Number 157)]
[Rules and Regulations]               
[Page 45643-45649]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr15au07-14]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2006-1026; FRL-8141-8]

 
Pyrasulfotole; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes a tolerance for residues of 
pyrasulfotole in or on small cereal grains, including barley, oats, 
rye, triticale, and wheat; as well as livestock commodities. Bayer 
CropScience requested this tolerance under the Federal Food, Drug, and 
Cosmetic Act (FFDCA).

DATES: This regulation is effective August 15, 2007. Objections and 
requests for hearings must be received on or before October 15, 2007, 
and must be filed in accordance with the instructions provided in 40 
CFR part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).

ADDRESSES: EPA has established a docket for this action under docket 
identification (ID) number EPA-HQ-OPP-2006-1026. 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 web site 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 Building), 2777 S. Crystal Drive, 
Arlington, VA. The Docket Facility is open from 8:30 a.m. to 4 p.m., 
Monday through Friday, excluding legal holidays. The Docket telephone 
number is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: Joanne I. Miller, Registration 
Division (7505P), Office of Pesticide Programs, Environmental 
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001; telephone number: (703) 305-6224; e-mail address: 
miller.joanne@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), 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 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 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 EPA's tolerance regulations at 
40 CFR part 180 through the Government Printing Office's pilot e-CFR 
site at http://www.gpoaccess.gov/ecfr.

C. Can I File an Objection or Hearing Request?

    Under section 408(g) of the FFDCA, any person may file an objection 
to any aspect of this regulation and may also

[[Page 45644]]

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-2006-1026 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 as 
required by 40 CFR part 178 on or before October 15, 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 this copy, identified by docket ID number 
EPA-HQ-OPP-2006-1026, 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 
Building), 2777 S. Crystal Drive, Arlington, VA. Deliveries are only 
accepted during the Docket's normal hours of operation (8:30 a.m. to 4 
p.m., Monday through Friday, excluding legal holidays). Special 
arrangements should be made for deliveries of boxed information. The 
Docket telephone number is (703) 305-5805.

II. Petition for Tolerance

    In the Federal Register of February 7, 2007 (72 FR 5706) (FRL-8111-
8), 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 
6F7059) by Bayer CropScience, 2 T.W. Alexander Drive, Research Triangle 
Park, NC 27709. The petition requested that 40 CFR 180.631 be amended 
by establishing a tolerance for residues of the herbicide pyrasulfotole 
(5-hydroxy-1,3-dimethyl-1H-pyrazol-4-yl)[2-(methylsulfonyl)-4-
(trifluoromethyl)phenyl]methanone, and its metabolite, 5-hydroxy-3-
methyl-1H-pyrazol-4-yl) [2-methylsulfornyl)-4-
(trifluoromethyl)phenyl]methanone, in or on barley, oat, rye, 
triticale, wheat, grain at 0.07 parts per million (ppm), barley, oat, 
rye, wheat, straw and oat, rye, wheat, forage at 0.25 ppm, barley, oat, 
wheat, hay at 0.8 ppm, wheat, aspirated grain fractions at 1.4 ppm. In 
addition, Bayer CropScience has requested permanent tolerances for 
pyrsulfotole per se for cattle, goat, hog, horse, sheep, meat and fat 
at 0.01 ppm, cattle, goat, hog, horse, sheep, meat byproducts at 0.3 
ppm, and milk at 0.005 ppm. That notice referenced a summary of the 
petition prepared by Bayer CropScience, the registrant, which is 
available to the public in the docket, http://www.regulations.gov. 

There were no comments received in response to the notice of filing.
    Based upon review of the data supporting the petition, EPA has 
modified the tolerance levels as follows: aspirated grain fractions at 
0.40 ppm, barley, grain at 0.02 ppm, barley, hay at 0.30 ppm, barley, 
straw at 0.20 ppm, cattle, fat at 0.02 ppm, cattle, liver at 0.35 ppm, 
cattle, meat at 0.02 ppm, cattle, meat byproducts, except liver at 0.06 
ppm, eggs at 0.02 ppm, goat, fat at 0.02 ppm, goat meat at 0.02 ppm, 
goat, meat byproducts, except liver at 0.06 ppm, hog, fat at 0.02 ppm, 
hog, meat at 0.02 ppm, hog, meat byproducts at 0.02 ppm, horse, fat at 
0.02 ppm, horse, liver at 0.35 ppm, horse, meat at 0.02 ppm, horse, 
meat byproducts, except liver at 0.06 ppm, milk at 0.01 ppm, oat, 
forage at 0.10 ppm, oat, grain at 0.08 ppm, oat, hay at 0.50 ppm, oat, 
straw at 0.20 ppm, poultry, fat at 0.02 ppm, poultry, meat at 0.02 ppm, 
poultry, meat byproducts at 0.02 ppm, rye, forage at 0.20 ppm, rye, 
grain at 0.02 ppm, rye, straw at 0.20 ppm, sheep, fat at 0.02 ppm, 
sheep, liver at 0.35 ppm, sheep, meat at 0.02 ppm, sheep, meat 
byproducts, except liver at 0.06 ppm, wheat, forage at 0.20 ppm, wheat, 
grain at 0.02 ppm, wheat, hay at 0.80 ppm, and wheat, straw at 0.20 
ppm.

III. Aggregate Risk Assessment and Determination of Safety

    Section 408(b)(2)(A)(i) of the 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 the 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 the 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....'' These provisions were added to the FFDCA by the Food 
Quality Protection Act (FQPA) of 1996.
    Consistent with FFDCA section 408(b)(2)(D), and the factors 
specified in section 408(b)(2)(D), 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 the petitioned-for tolerance 
for residues of pyrasulfotole and pyrasulfotole-desmethyl on aspirated 
grain fractions at 0.40 ppm, barley, grain at 0.02 ppm, barley, hay at 
0.30 ppm, barley, straw at 0.20 ppm, cattle, fat at 0.02 ppm, cattle, 
liver at 0.35 ppm, cattle, meat at 0.02 ppm, cattle, meat byproducts, 
except liver at 0.06 ppm, eggs at 0.02 ppm, goat, fat at 0.02 ppm, goat 
meat at 0.02 ppm, goat, meat byproducts, except liver at 0.06 ppm, hog, 
fat at 0.02 ppm, hog, meat at 0.02 ppm, hog, meat byproducts at 0.02 
ppm, horse, fat at 0.02 ppm, horse, liver at 0.35 ppm, horse, meat at 
0.02 ppm, horse, meat byproducts, except liver at 0.06 ppm, milk at 
0.01 ppm, oat, forage at 0.10 ppm, oat, grain at 0.08 ppm, oat, hay at 
0.50 ppm, oat, straw at 0.20 ppm, poultry, fat at 0.02 ppm, poultry, 
meat at 0.02 ppm, poultry, meat byproducts at 0.02 ppm, rye, forage at 
0.20 ppm, rye, grain at 0.02 ppm, rye, straw at 0.20 ppm, sheep, fat at 
0.02 ppm, sheep, liver at 0.35 ppm, sheep, meat at 0.02 ppm, sheep, 
meat byproducts, except liver at 0.06 ppm, wheat, forage at 0.20 ppm, 
wheat, grain at 0.02 ppm, wheat, hay at 0.80 ppm, and wheat, straw at 
0.20 ppm. EPA's assessment of exposures and risks associated with 
establishing the tolerance follows.
    For pyrasulfotole, aggregate exposure risk assessments were 
performed for the following scenarios: Acute aggregate exposure (food 
and drinking water), and chronic aggregate exposure (food and drinking 
water). Short- and intermediate-term assessments, which are used to 
evaluate aggregate dietary and residential exposures, were not 
performed because there are no registered or proposed residential non-
food uses. Although pyrasulfotole is classified as ``Suggestive 
Evidence of Carcinogenicity,'' EPA determined that separate 
quantifications of cancer risks is not required noting that the 
progression of non-neoplastic related lesions in both the rats and mice 
was biologically plausible by non-genotoxic

[[Page 45645]]

modes of action for both the corneal tumors and the bladder tumors. 
Therefore, the chronic RfD will be protective of cancer and non-cancer 
effects.
    Pyrasulfotole belongs to a class of herbicides that inhibit the 
liver enzyme 4-hydroxyphenylpyruvate dioxygenase (HPPD), which is 
involved in the catabolism (metabolic breakdown) of tyrosine (an amino 
acid derived from proteins in the diet). Inhibition of HPPD can result 
in elevated tyrosine levels in the blood, a condition called 
tyrosinemia. HPPD-inhibiting herbicides have been found to cause a 
number of toxicities in laboratory animal studies including ocular, 
developmental, liver, and kidney effects. Of these toxicities, it is 
the ocular effect (corneal opacity) that is highly correlated with the 
elevated blood tyrosine levels. In fact, rats dosed with tyrosine alone 
show ocular opacities similar to those seen with HPPD inhibitors. 
Although the other toxicities may be associated with chemically-induced 
tyrosinemia, other mechanisms may also be involved.
    There are marked differences among species in the ocular toxicity 
associated with inhibition of HPPD. Ocular effects following treatment 
with HPPD inhibitor herbicides are seen in the rat but not in the 
mouse. Monkeys also seem to be recalcitrant to the ocular toxicity 
induced by HPPD inhibition. The explanation of this species-specific 
response in ocular opacity is related to the species differences in the 
clearance of tyrosine. A metabolic pathway exists to remove tyrosine 
from the blood that involves a liver enzyme called tyrosine 
aminotransferase (TAT). In contrast to rats where ocular toxicity is 
observed following exposure to HPPD-inhibiting herbicides, mice and 
human are unlikely to achieve the levels of plasma tyrosine necessary 
to produce ocular opacities because the activity of TAT in these 
species is much greater compared to rats. Thus, humans and mice have a 
highly effective metabolic process for handling excess tyrosine.
    HPPD inhibitors (e.g., Nitisinone) are used as an effective 
therapeutic agent to treat patients suffering from rare genetic 
diseases of tyrosine catabolism. Treatment starts in childhood but is 
often sustained throughout patient's lifetime. The human experience 
indicates that a therapeutic dose (1 mg/kg/day dose) of Nitisinone has 
an excellent safety record in infants, children, and adults and that 
serious adverse health outcomes have not been observed in a population 
followed for approximately a decade. Rarely, ocular effects are seen in 
patients with high plasma tyrosine levels; however these effects are 
transient and can be readily reversed upon adherence to a restricted 
protein diet. This indicates that an HPPD inhibitor in it of itself 
cannot easily overwhelm the tyrosine-clearance mechanism in humans.
    Therefore, exposure to environmental residues of HPPD-inhibiting 
herbicides are unlikely to result in the high blood levels of tyrosine 
and ocular toxicity in humans due to an efficient metabolic process to 
handle excess tyrosine. Nonetheless, because EPA has not yet developed 
an alternate risk assessment endpoint, model, or cross-species 
extrapolation method for pyrasulfotole, EPA has assessed chronic risk 
from exposure to pyrasulfotole based on its ocular effects in rats. Due 
to the limited relevance to humans of this endpoint, this approach to 
assessing chronic risk for pyrasulfotole must be regarded as worst 
case. In the future, assessment of HPPD-inhibiting herbicides will 
consider more appropriate models and cross species extrapolation 
methods.

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 adverse effects caused by pyrasulfotole 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.
 The referenced document, entitled ``Pyrasulfotole: 

Human Health Risk Assessment for Proposed Uses on Small Cereal 
Grains,'' is available in the docket established by this action, (EPA-
HQ-OPP-2006-1026).

B. Toxicological Endpoints

    For hazards that have a threshold below which there is no 
appreciable risk, the toxicological level of concern (LOC) is derived 
from the highest dose at which no adverse effects are observed (the 
NOAEL) in the toxicology study identified as appropriate for use in 
risk assessment. However, if a NOAEL cannot be determined, the lowest 
dose at which adverse effects of concern are identified (the LOAEL) is 
sometimes used for risk assessment. Uncertainty/safety factors (UF) are 
used in conjunction with the LOC to take into account 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. Safety is assessed for acute and chronic 
risks by comparing aggregate exposure to the pesticide to the acute 
population adjusted dose (aPAD) and chronic population adjusted dose 
(cPAD). The aPAD and cPAD are calculated by dividing the LOC by all 
applicable uncertainty/safety factors. Short-, intermediate, and long-
term risks are evaluated by comparing aggregate exposure to the LOC to 
ensure that the margin of exposure (MOE) called for by the product of 
all applicable uncertainty/safety factors is not exceeded.
    For non-threshold risks, the Agency assumes that any amount of 
exposure will lead to some degree of risk and estimates risk in terms 
of the probability of occurrence of additional adverse cases. 
Generally, cancer risks are considered non-threshold. 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/fedrgstr/EPA-PEST/1997/November/Day-26/p30948.htm
.

    A summary of the toxicological endpoints for pyrasulfotole used for 
human risk assessment is shown in Table 1. of this unit.

[[Page 45646]]

    Table 1.--Summary of Toxicological Dose and Endpoints for Pyrasulfotole for Use in Human Risk Assessment
----------------------------------------------------------------------------------------------------------------
                                          Dose Used in Risk     Uncertainty/FQPA Safety  Study and Toxicological
          Exposure/Scenario                   Assessment               Factors\1\                Effects
----------------------------------------------------------------------------------------------------------------
Acute Dietary (All populations)        NOAEL = 3.8 mg/kg/day    UFA = 10X                Developmental
                                                                UFH = 10X..............   neurotoxicity (rat;
                                                                UFFQPA = 1X............   dietary) offspring
                                                                                         LOAEL = 37 mg/kg/day
                                                                                          based on delayed
                                                                                          preputial separation
                                                                                          (males), decreased
                                                                                          cerebrum length (PND
                                                                                          21 females), and
                                                                                          decreased cerebellum
                                                                                          height (PND 21 males)
----------------------------------------------------------------------------------------------------------------
Chronic Dietary (All populations)      NOAEL= 1.0 mg/kg/day     UFA = 10X                Combined chronic
                                                                UFH = 10X..............   toxicity/
                                                                UFFQPA = 1X............   carcinogenicity (rat;
                                                                                          dietary)
                                                                                         LOAEL = 10/14 mg/kg/day
                                                                                          (M/F) based on corneal
                                                                                          opacity,
                                                                                          neovascularization of
                                                                                          the cornea,
                                                                                          inflammation of the
                                                                                          cornea, regenerative
                                                                                          corneal hyperplasia,
                                                                                          corneal atrophy, and /
                                                                                          or retinal atrophy
                                                                                          (both sexes), and
                                                                                          hepatocellar
                                                                                          hypertrophy along with
                                                                                          increased serum
                                                                                          cholesterol (males)
----------------------------------------------------------------------------------------------------------------
Incidental Oral Short-and              NOAEL= 2.5 mg/kg/day     UFA = 10X                Reproduction and
 Intermediate-Term (1-30 days and 1-6                           UFH = 10X..............   fertility effects
 months)                                                        UFFQPA = 1X............   (rat; dietary)
                                                                                          offspring
                                                                                         LOAEL = 26.3/32.6 mg/kg
                                                                                          bw/day (M/F) based on
                                                                                          corneal opacity and/or
                                                                                          corneal
                                                                                          neovascularization (F1
                                                                                          and F2 generations)
----------------------------------------------------------------------------------------------------------------
Dermal Short- and Intermediate-Term    NOAEL = 10 mg/kg/day     UFA = 10X                28-day dermal toxicity
 (1-30 days and 1-6 months)                                     UFH = 10X..............   (rat)
                                                                                         LOAEL = 100 mg/kg bw/
                                                                                          day (M/F) based on
                                                                                          focal degeneration of
                                                                                          pancreas (both sexes)
                                                                                          and alteration of
                                                                                          thyroid colloid
                                                                                          (males)
----------------------------------------------------------------------------------------------------------------
Dermal Long-Term (> 6 months)          NOAEL= 1.0 mg/kg/day     UFA = 10X                Combined chronic
                                       Estimated dermal         UFH = 10X..............   toxicity/
                                        absorption factor =                               carcinogenicity (rat;
                                        2.5%.                                             dietary)
                                                                                         LOAEL = 10/14 mg/kg/day
                                                                                          (M/F) based on corneal
                                                                                          opacity,
                                                                                          neovascularization of
                                                                                          the cornea,
                                                                                          inflammation of the
                                                                                          cornea, regenerative
                                                                                          corneal hyperplasia,
                                                                                          corneal atrophy, and/
                                                                                          or retinal atrophy
                                                                                          (both sexes), and
                                                                                          hepatocellular
                                                                                          hypertrophy along with
                                                                                          increased serum
                                                                                          cholesterol (males)
----------------------------------------------------------------------------------------------------------------
Inhalation (All durations)             NOAEL = 1.0 mg/kg/day    UFA = 10X                Combined chronic
                                       100% inhalation asumed.  UFH = 10X..............   toxicity/
                                                                                          carcinogenicity (rat;
                                                                                          dietary)
                                                                                         LOAEL = 10/14 mg/kg/day
                                                                                          (M/F) based on corneal
                                                                                          opacity,
                                                                                          neovascularization of
                                                                                          the cornea,
                                                                                          inflammation of the
                                                                                          cornea, regenerative
                                                                                          corneal hyperplasia,
                                                                                          corneal atrophy, and/
                                                                                          or retinal atrophy
                                                                                          (both sexes), and
                                                                                          hepatocellular
                                                                                          hypertrophy along with
                                                                                          increased serum
                                                                                          cholesterol (males)
----------------------------------------------------------------------------------------------------------------
Cancer (Oral, dermal, inhalation)       Classification: ``Suggestive Evidence of Carcinogenic Potential'' based
                                              on increased incidences of corneal tumors in male rats (oral
                                          carcinogenicity study) and urinary bladder tumors in male and female
                                                            mice (oral carcinogenicity study)
----------------------------------------------------------------------------------------------------------------
\1\UF = Uncertainty factor, UFA = Extrapolation from animal to human (interspecies), UFH = Potential variation
  in sensitivity among members of the human population (intraspecies), and UFFQPA = Food Quality Protection Act
  (FQPA) safety factor.

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. In evaluating dietary 
exposure to pyrasulfotole, EPA assessed dietary exposures from 
pyrasulfotole in food as follows:
    i. Acute exposure. Quantitative acute dietary exposure and risk 
assessments are performed for a food-use pesticide, if a toxicological 
study has indicated the possibility of an effect of concern occurring 
as a result of a one-day or single exposure. In estimating acute 
dietary exposure, EPA used food consumption information from the United 
States Department of Agriculture (USDA) 1994-1996 and 1998 Nationwide 
Continuing Surveys of Food Intake by Individuals (CSFII). As to residue 
levels in food, EPA relied upon tolerance-level residues and assuming 
100% crop treated information for all commodities.
    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 relied upon 
tolerance-level residues and assuming 100% crop treated information for 
all commodities.
    iii. Cancer. Pyrasulfotole has been classified by the EPA as having 
``Suggestive Evidence of Carcinogenic Potential,'' based on increased 
incidences of corneal tumors in male rats at the highest dose tested 
(2,500 ppm) in the chronic toxicity/

[[Page 45647]]

carcinogenicity study in rat and urinary bladder transitional cell 
tumors in male and female mice at the highest dose tested (4,000 ppm) 
in the mouse carcinogenicity study. These tumors were observed at doses 
that were considered excessive due to increased mortality caused by 
urinary bladder stones. EPA noted that the progression of non-
neoplastic related lesions in both the rats and mice was biologically 
plausible by non-genotoxic modes of action for both the corneal tumors 
and the bladder tumors. Therefore, the chronic RfD of 0.01 mg/kg/day, 
based on the rat chronic toxicity/carcinogenicity study (NOAEL= 25 ppm 
(1 mg/kg/day) and LOAEL of 250 ppm (10 mg/kg/day)) would be protective 
of both non-cancer and potential cancer precursor effects. 
Quantifications of separate cancer risk was not required.
    2. Dietary exposure from drinking water. The Agency lacks 
sufficient monitoring data to complete a comprehensive dietary exposure 
analysis and risk assessment for pyrasulfotole 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 environmental 
fate characteristics of pyrasulfotole. 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 FIRST and SCI-GROW models, the estimated drinking 
water environmental concentrations (EDWCs) of pyrasulfotole for acute 
exposures are estimated to be 4.0 parts per billion (ppb) for surface 
water and 1.4 ppb for ground water. The EECs for chronic exposures are 
estimated to be 2.8 ppb for surface water and 1.4 ppb for ground water.
    Modeled estimates of drinking water concentrations were directly 
entered into the dietary exposure model. For acute dietary risk 
assessment, the water concentration value of 4.0 ppb was used to access 
the contribution to drinking water. For chronic dietary risk 
assessment, the water concentration of value 2.8 ppb was used to access 
the contribution to drinking water.
    The pyrasulfotole risk assessment team determined that the residue 
of concern in drinking water for risk assessment purposes is parent 
only. Pyrasulfotole-benzoic acid was identified as the only 
environmental degradate in the soil metabolism and terrestrial field 
dissipation studies. Based on available toxicology studies on 
pyrasulfotole-benzoic acid, EPA determined that it is not of 
toxicological concern, and thus, should not be included in the drinking 
water assessment for pyrasulfotole.
    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). Pyrasulfotole is not 
proposed or 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 the FFDCA requires that, when 
considering whether to establish, modify, or revoke a tolerance, the 
Agency consider ``available information'' concerning the cumulative 
effects of a particular pesticide's residues and ``other substances 
that have a common mechanism of toxicity.''
    Pyrasulfotole belongs to a class of herbicides (including 
mesotrione, isoxaflutole, and topramezone) that inhibit the liver 
enzyme 4-hydroxyphenylpyruvate dioxygenase (HPPD). EPA has concluded 
that the ocular effects caused by these herbicides has limited 
relevance to humans. In the future, assessments of HPPD-inhibiting 
herbicides will consider more appropriate models and cross species 
extrapolation methods.
    For information regarding EPA's efforts to determine which 
chemicals have a common mechanism of toxicity and to evaluate the 
cumulative effects of such chemicals, see EPA's website at http://www.epa.gov/pesticides/cumulative
.

D. Safety Factor for Infants and Children

    1. In general. Section 408 of FFDCA provides that EPA shall apply 
an additional (10X) 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 data base 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. 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 FQPA 
safety factor value based on the use of traditional uncertainty/safety 
factors and/or special FQPA safety factors, as appropriate.
    2. Prenatal and postnatal sensitivity. Increased quantitative 
susceptibility of offspring was observed in the rabbit developmental 
toxicity study, since offspring toxicity (skeletal anomalies/
variations) was observed at a lower dose than maternal toxicity 
(decreased body weight gain, food consumption). No evidence of 
quantitative susceptibility following in utero and/or postnatal 
exposure was observed in the prenatal developmental toxicity study in 
rats, the developmental neurotoxicity (DNT) study in rats, or in the 2-
generation rat reproductive toxicity study. Offspring toxicity 
(skeletal variations; decreased body weight (males)) was observed at 
the same dose as maternal toxicity (clinical signs, decreased body 
weight, enlarged placenta) in the prenatal developmental toxicity study 
in rats. Offspring toxicity (e.g., ocular toxicity, effects on 
learning/memory, effects on brain morphometry) was also observed at the 
same dose as maternal toxicity (ocular opacity) in the DNT study. Last, 
offspring toxicity (ocular toxicity) was observed at the same as or 
higher doses than parental toxicity (thyroid effects) in the 2-
generation rat reproductive toxicity study.
    3. Conclusion. EPA has determined that reliable data show that it 
would be safe for infants and children to reduce the FQPA safety factor 
to 1X. That decision is based on the following findings:
    i. The toxicology database is complete.
    ii. There are no residual uncertainties concerning pre- and 
postnatal toxicity. Clear NOAELs were established for all exposure 
scenarios and these are considered protective of the offspring 
susceptibility observed in the rabbit developmental toxicity study. The 
concern for increased susceptibility seen in rabbit developmental 
toxicity study is low because a) there is well established 
developmental NOAEL in the rabbit developmental toxicity study in 
rabbits protecting fetuses from skeletal anomalies/variations, b) the 
increased succeptibility was not seen in rat developmental toxicity 
study, developmental neurotoxicity study in rats and two generation 
reproduction study in rats, c) the NOAEL of the study chosen for the 
chronic RfD is 10x lower than the rabbit developmental toxicity study 
NOAEL (10 mg/kg/day).
    iii. There are no registered or proposed uses of pyrasulfotole 
which would result in residential exposure.
    iv. There are no residual uncertainties identified in the exposure 
databases. The dietary food exposure assessments were performed based 
on 100% crop treated and tolerance-level residues for

[[Page 45648]]

all proposed commodities. By using this screening-level assessment, the 
acute and chronic exposures/risks will not be underestimated. The 
dietary drinking water assessment (unrefined estimates) utilizes values 
generated by model and associated modeling parameters which are 
designed to provide conservative, health protective, high-end estimates 
of water concentrations.

E. Aggregate Risks and Determination of Safety

    Safety is assessed for acute and chronic risks by comparing 
aggregate exposure to the pesticide to the acute population adjusted 
dose (aPAD) and chronic population adjusted dose (cPAD). The aPAD and 
cPAD are calculated by dividing the LOC by all applicable uncertainty/
safety factors. For linear cancer risks, EPA calculates the probability 
of additional cancer cases given aggregate exposure. Short-, 
intermediate, and long-term risks are evaluated by comparing aggregate 
exposure to the LOC to ensure that the margin of exposure (MOE) called 
for by the product of all applicable uncertainty/safety factors is not 
exceeded.
    1. Acute risk. Using the exposure assumptions discussed in this 
unit for acute exposure, the acute dietary exposure from food and water 
to pyrasulfotole and pyrasulfotole-desmethyl will occupy 2% of the aPAD 
for the general U.S. population and at 4% of the aPAD for children 1-2 
years old, the most highly exposed population subgroup.
    2. Chronic risk. Using the exposure assumptions described in this 
unit for chronic exposure, EPA has concluded that exposure to 
pyrasulfotole and pyrasulfotole-desmethyl from food and water will 
utilize 2% of the cPAD for the general U.S. population and at 7% of the 
cPAD for children 1-2 years old, the most highly exposed population 
subgroup.
    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). Pyrasulfotole 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.
    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). Pyrasulfotole 
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. Pyrasulfotole has 
been classified by EPA as having ``Suggestive Evidence of Carcinogenic 
Potential,'' based on increased incidences of corneal tumors in male 
rats at the highest dose tested (2,500 ppm) in the chronic toxicity/
carcinogenicity study in rat and urinary bladder transitional cell 
tumors in male and female mice at the highest dose tested (4,000 ppm) 
in the mouse carcinogenicity study. The chronic RfD of 0.01 mg/kg/day, 
based on the rat chronic toxicity/carcinogenicity study (NOAEL = 25 ppm 
(1 mg/kg/day) and LOAEL of 250 ppm (10 mg/kg/day)) would be protective 
of both non-cancer and cancer effects.
    6. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
to the general population, or to infants and children from aggregate 
exposure to pyrasulfotole and pyrasulfotole-desmethyl residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    Adequate enforcement methodology high-performance liquid 
chromatography (HPLC)/mass spectrometry (MS)/MS method (Method AI-004-
A05-01) 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 no established Mexican, Canadian, or Codex MRLs for the 
proposed uses. Pyrasulfotole was evaluated as part of a trilateral 
joint review with Canada and Australia. All EPA-recommended tolerances 
are the same as those being established in Canada and Australia. 
Therefore, harmonization is not an issue at this time.

V. Conclusion

    Therefore, the tolerance is established for residues of 
pyrasulfotole and pyrasulfotole-desmethyl, (5-hydroxy-1,3-dimethyl-1H-
pyrazol-4-yl)[2-(methylsulfonyl)-4-(trifluoromethyl)phenyl]methanone, 
and its metabolite, 5-hydroxy-3-methyl-1H-pyrazol-4-yl) [2-
methylsulfornyl)-4-(trifluoromethyl)phenyl]methanone, in or on 
aspirated grain fractions at 0.40 ppm, barley, grain at 0.02 ppm, 
barley, hay at 0.30 ppm, barley, straw at 0.20 ppm, cattle, fat at 0.02 
ppm, cattle, liver at 0.35 ppm, cattle, meat at 0.02 ppm, cattle, meat 
byproducts, except liver at 0.06 ppm, eggs at 0.02 ppm, goat, fat at 
0.02 ppm, goat meat at 0.02 ppm, goat, meat byproducts, except liver at 
0.06 ppm, hog, fat at 0.02 ppm, hog, meat at 0.02 ppm, hog, meat 
byproducts at 0.02 ppm, horse, fat at 0.02 ppm, horse, liver at 0.35 
ppm, horse, meat at 0.02 ppm, horse, meat byproducts, except liver at 
0.06 ppm, milk at 0.01 ppm, oat, forage at 0.10 ppm, oat, grain at 0.08 
ppm, oat, hay at 0.50 ppm, oat, straw at 0.20 ppm, poultry, fat at 0.02 
ppm, poultry, meat at 0.02 ppm, poultry, meat byproducts at 0.02 ppm, 
rye, forage at 0.20 ppm, rye, grain at 0.02 ppm, rye, straw at 0.20 
ppm, sheep, fat at 0.02 ppm, sheep, liver at 0.35 ppm, sheep, meat at 
0.02 ppm, sheep, meat byproducts, except liver at 0.06 ppm, wheat, 
forage at 0.20 ppm, wheat, grain at 0.02 ppm, wheat, hay at 0.80 ppm, 
and wheat, straw at 0.20 ppm.

VI. Statutory and Executive Order Reviews

    This final rule establishes a tolerance under section 408(d) of 
FFDCA in response to a petition submitted to the Agency. The Office of 
Management and Budget (OMB) has exempted these types of actions from 
review under Executive Order 12866, entitled Regulatory Planning and 
Review (58 FR 51735, October 4, 1993). Because this rule has been 
exempted from review under Executive Order 12866, 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) or Executive Order 13045, entitled Protection of Children 
from Environmental Health Risks and Safety Risks (62 FR 19885, April 
23, 1997). This final rule does not contain any information collections 
subject to OMB approval under the Paperwork Reduction Act (PRA), 44 
U.S.C. 3501 et seq., nor does it require any special considerations 
under Executive Order 12898, entitled Federal Actions to Address 
Environmental Justice in Minority Populations and Low-Income 
Populations (59 FR 7629, February 16, 1994).
    Since tolerances and exemptions that are established on the basis 
of a petition under section 408(d) of FFDCA, such as the tolerance in 
this final rule, do not require the issuance of a proposed rule, the 
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et 
seq.) do not apply.

[[Page 45649]]

    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 6, 
2000) do not apply to this rule. In addition, This 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: August 1, 2007.
Debra Edwards,
Director, Office of Pesticide Programs.

0
Therefore, 40 CFR part 180 is amended as follows:

PART 180--[AMENDED]

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

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

0
2. Section 180.631 is added to read as follows:

Sec.  180.631  Pyrasulfotole; tolerances for residues.

    (a) General. Tolerances are established for residues of the 
herbicide pyrasulfotole and pyrasulfotole-desmethyl, (5-hydroxy-1,3-
dimethyl-1H-pyrazol-4-yl)[2-(methylsulfonyl)-4-
(trifluoromethyl)phenyl]methanone, and its metabolite, 5-hydroxy-3-
methyl-1H-pyrazol-4-yl) [2-methylsulfornyl)-4-
(trifluoromethyl)phenyl]methanone, in or on the following agricultural 
commodities:

------------------------------------------------------------------------
                                                              Parts per
                         Commodity                             million
------------------------------------------------------------------------
Aspirated grain fractions..................................         0.40
Barley, grain..............................................         0.02
Barley, hay................................................         0.30
Barley, straw..............................................         0.20
Cattle, fat................................................         0.02
Cattle, liver..............................................         0.35
Cattle, meat...............................................         0.02
Cattle, meat byproducts, except liver......................         0.06
Eggs.......................................................         0.02
Goat, fat..................................................         0.02
Goat, liver................................................         0.35
Goat, meat.................................................         0.02
Goat, meat byproducts, except liver........................         0.06
Hog, fat...................................................         0.02
Hog, meat..................................................         0.02
Hog, meat byproducts.......................................         0.02
Horse, fat.................................................         0.02
Horse, liver...............................................         0.35
Horse, meat................................................         0.02
Horse, meat byproducts, except liver.......................         0.06
Milk.......................................................         0.01
Oat, forage................................................         0.10
Oat, grain.................................................         0.08
Oat, hay...................................................         0.50
Oat, straw.................................................         0.20
Poultry, fat...............................................         0.02
Poultry, meat..............................................         0.02
Poultry, meat byproducts...................................         0.02
Rye, forage................................................         0.20
Rye, grain.................................................         0.02
Rye, straw.................................................         0.20
Sheep, fat.................................................         0.02
Sheep, liver...............................................         0.35
Sheep, meat................................................         0.02
Sheep, meat byproducts, except liver.......................         0.06
Wheat, forage..............................................         0.20
Wheat, grain...............................................         0.02
Wheat, hay.................................................         0.80
Wheat, straw...............................................         0.20
------------------------------------------------------------------------

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

[FR Doc. E7-15698 Filed 8-14-07; 8:45 am]

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