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Penoxsulam (Dow AgroSciences). September 24, 2004. Pesticide tolerance. Final Rule. Federal Register.

Docket identification (ID) number OPP-2004-0286.

http://www.epa.gov/fedrgstr/EPA-PEST/2004/September/Day-24/p21502.htm

[Federal Register: September 24, 2004 (Volume 69, Number 185)]
[Rules and Regulations]
[Page 57188-57197]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr24se04-11]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-2004-0286; FRL-7678-6]

Penoxsulam, 2-(2,2-difluoroethoxy)-N-(5,8-dimethoxy[1,2,4]
triazolo[1,5-c]pyrimidin-2-yl)-6-(trifluoromethyl)benzenesulfonamide;
Pesticide Tolerance
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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[[Page 57189]]
SUMMARY: This regulation establishes a tolerance for residues of
penoxsulam 2-(2,2-difluoroethoxy)-N-(5,8-dimethoxy[1,2,4]triazolo[1,5-
c]pyrimidin-2-yl)-6-(trifluoromethyl)benzenesulfonamide in or on
rice,grain and rice, straw. Dow AgroSciences LLC requested this
tolerance 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 September 24, 2004. Objections and
requests for hearings must be received on or before November 23, 2004.
ADDRESSES: To submit a written objection or hearing request follow the
detailed instructions as provided in Unit VI. of the SUPPLEMENTARY
INFORMATION. EPA has established a docket for this action under Docket
identification (ID) number OPP-2004-0286. All documents in the docket
are listed in the EDOCKET index at http://www.epa.gov/edocket. Although
listed in the index, some information is not publicly available, i.e.,
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 either electronically
in EDOCKET or in hard copy at the Public Information and Records
Integrity Branch (PIRIB), Rm. 119, Crystal Mall #2, 1801 S.
Bell St., Arlington, VA. This 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 (7505C), 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:
• Crop production (NAICS 111), e.g., agricultural workers;
greenhouse, nursery, and floriculture workers; farmers.
• Animal production (NAICS 112), e.g., cattle ranchers and
farmers, dairy cattle farmers, livestock farmers.
• Food manufacturing (NAICS 311), e.g., agricultural
workers; farmers; greenhouse, nursery, and floriculture workers;
ranchers; pesticide applicators.
• Pesticide manufacturing (NAICS 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 and Other
Related Information?
In addition to using EDOCKET (http://www.epa.gov/edocket/), you may
access this Federal Register document electronically through the EPA
Internet under the ``Federal Register'' listings at http://www.epa.gov/
fedrgstr/. A frequently updated electronic version of 40 CFR part 180
is available at E-CFR Beta Site Two at http://www.gpoaccess.gov/ecfr/.
To access the OPPTS Harmonized Guidelines referenced in this
document, go directly to the guidelines at
http://www.epa.gov/opptsfrs/home/guidelin.htm.
II. Background and Statutory Findings
In the Federal Register of August 6, 2003 (68 FR 46609) (FRL-7320-
4), 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
3F6542) by Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN
46268-1054. The petition requested that 40 CFR part 180 be amended by
establishing a tolerance for residues of the herbicide penoxsulam, 2-
(2,2-difluoroethoxy)-N-(5,8-dimethoxy[1,2,4]triazolo[1,5-c]pyrimidin-2-
yl)-6-(trifluoromethyl)benzenesulfonamide, in or on rice, grain at 0.01
parts per million (ppm), rice, straw at 0.5 ppm, rice, hulls at 0.01
ppm, rice, bran at 0.01 ppm, and rice, polished rice at 0.01 ppm. That
notice included a summary of the petition prepared by Dow AgroSciences
LLC, the registrant. There were no comments received in response to the
notice of filing. The tolerance for rice grain was increased to 0.02
ppm to reflect the submitted field residue data. Residues of penoxsulam
do not concentrate in the processed commodities, rice hull, bran, or
polished rice, therefore any residues of penoxsulam on these
commodities will be covered by the tolerance on rice, grain.
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 the final rule on
Bifenthrin Pesticide Tolerances (62 FR 62961, November 26, 1997) (FRL-
5754-7).
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 residues of penoxsulam on rice,
grain at 0.02 ppm and rice, straw at 0.5 ppm. No tolerances were
necessary for the rice process commodities, rice hulls, bran, or
polished rice, because residues will not exceed the established
tolerance in rice, grain. EPA's assessment of exposures and risks
associated with establishing the tolerance follows.
[[Page 57190]]

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. The nature of the toxic effects caused by penoxsulam are
discussed in Table 1 of this unit as well as the no-observed-adverse-
effect-level (NOAEL) and the lowest-observed-adverse-effect-level
(LOAEL) from the toxicity studies reviewed.

Table 1.--Subchronic, Chronic, and Other Toxicity
Guideline No. Study Type Results
870.3100 90-day oral toxicity-rat NOAEL = Male (M): 50/Female (F): 250
milligrams/kilogram/day (mg/kg/day)
LOAEL = M: 250 mg/kg/day based on decease body weight/body weight gain (bw/bwg), decease food consumption, and decease RBC parameters and F:500 mg/kg/day based on increase mineralization and hyperplasia of the kidney pelvic epithelium
870.3100 90-day oral toxicity-mouse NOAEL= M:1027 highest dose tested (HDT)/
F:1029 HDT mg/kg/day
LOAEL= M: Not determined, >1027 HDT/F:>1029
HDT mg/kg/day
870.3150 90-day oral toxicity- dog NOAEL = M: 17.8/F: 19.9 mg/kg/day
LOAEL = M:49.4/F:57.1 mg/kg/day based on histopathologic changes in kidney
870.3200 28-day dermal Test
Material: technical 		NOAEL = M:1,000/F:1,000 mg/kg/day
LOAEL = M:>1,000 HDT/F: >1,000 HDT
870.3200 Test Material: 21.9% formulated GF-443 material, rat NOAEL= M:500/F:1,000 mg/kg/day
LOAEL = M:1,000 mg/kg/day based on very slight hyperplasia at test site and
F:>1,000 HDT mg/kg/day
870.3700 Prenatal developmental-rat Maternal NOAEL = 500 mg/kg/day
Maternal LOAEL = 1,000 mg/kg/day based on decease bwg, decease food consumption, and decease kidney weights
Developmental NOAEL = 1,000 HDT mg/kg/day
Developmental LOAEL = >1,000 HDT
870.3700 Prenatal developmental- Maternal NOAEL = 25 mg/kg/day
rabbit Maternal LOAEL = 75 mg/kg/day based on death, clinical signs, decease bwg, and decease food consumption
Developmental NOAEL = 75 mg/kg/day
Developmental LOAEL = >75 HDT
870.3800 2-Generation Reproduction and fertility effects in rats Parental/Systemic NOAEL = M:100/F:30 mg/kg/ day
Parental/Systemic LOAEL = M:300 mg/kg/day based on decease bw of F1 males
Parental/Systemic LOAEL = F:100 mg/kg/day based on kidney lesions
Reproductive/Offspring NOAEL = 30 mg/kg/day
Reproductive/Offspring LOAEL = 100 mg/kg/day based on delayed preputial separation
870.4100 Chronic toxicity-dogs NOAEL = M:14.7/F:44.8 HDT mg/kg/day
LOAEL = M:46.2 mg/kg/day based on slight
multifocal hyperplasia in the kidney epithelium and F:> 44.8 HDT
870.4100 Chronic toxicity- rats NOAEL = M:50/F:50 mg/kg/day
LOAEL = M:250 mg/kg/day based on decease bw/ bwg, decease RBC parameters, increase BUN, increase urine volume, decease urine specific gravity, increase kidney wt., increase crystals/calculi in kidney and urinary bladder, hyperplasia of kidney pelvis epithelium and urinary bladder mucosa, and increase severity of chronic glomerulonephropathy
870.4200 Carcinogenicity- rats LOAEL = F:250 mg/kg/day based on decease bw/ bwg, increase urine volume, increase crystals/calculi in urinary bladder, hyperplasia of kidney pelvis epithelium and urinary bladder mucosa
870.4200 Carcinogenicity Evidence of carcinogenicity in male rats based on possibly treatment related increase incidence of Large Granular Lymphocyte (LGL) Leukemia at 5, 50, & 250 mg/kg/day. Also increase severity at 250 mg/kg/day.
Female rats - negative for carcinogenicity,
but dosing was only marginally adequate.
870.4300 Carcinogenicity-mice NOAEL = M:>375 HDT/F:>750 HDT mg/kg/day
LOAEL = M:>375 HDT/F:>750 HDT
In males, negative for carcinogenicity at
doses tested. Dosing inadequate.
In females, negative for carcinogenicity at
the doses tested. Dosing adequate (750 mg/
kg/day is sufficiently close to limit dose
of 1,000 mg/kg/day).
870.5100 MUTA-Reverse Gene mutation - S.typhimurium/E. coli activation Negative with and without rat S-9
870.5300 Muta-forward gene mutation (CHO Cells/HGPRT locus) Negative with and without rat S-9
activation
870.5375 Muta-in vitro Mammalian (Chromosomal activiation
aberrations in primary
rat lymphocytes)		 Negative with and without rat S-9
Cytogenetics
870.5395 Muta-in vivo Micronucleus, Mice (bone marrow cells) Negative at oral doses (once per day on two
consecutive days) of up to 2,000 mg/kg
870.6200 Acute neurotoxicity screening battery NOAEL = M/F 2,000 HDT mg/kg/day
LOAEL = M/F >2,000 HDT
870.6200 Chronic neurotoxicity screening battery NOAEL = M/F 250 mg/kg/day
LOAEL = M/F >250 (HDT) mg/kg/day




[[Page 57191]]

B. Toxicological Endpoints
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. An UF of 100 is routinely used, 10X to account for
interspecies differences and 10X for intraspecies differences.
Three other types of safety or uncertainty factors may be used:
``Traditional uncertainty factors;'' the ``special FQPA safety
factor;'' and the ``default FQPA safety factor.'' By the term
``traditional uncertainty factor,'' EPA is referring to those
additional uncertainty factors used prior to FQPA passage to account
for database deficiencies. These traditional uncertainty factors have
been incorporated by the FQPA into the additional safety factor for the
protection of infants and children. The term ``special FQPA safety
factor'' refers to those safety factors that are deemed necessary for
the protection of infants and children primarily as a result of the
FQPA. The ``default FQPA safety factor'' is the additional 10X safety
factor that is mandated by the statute unless it is decided that there
are reliable data to choose a different additional factor (potentially
a traditional uncertainty factor or a special FQPA safety factor).
For dietary risk assessment (other than cancer) the Agency uses the
UF to calculate an acute or chronic reference dose (acute RfD or
chronic RfD) where the RfD is equal to the NOAEL divided by an UF of
100 to account for interspecies and intraspecies differences and any
traditional uncertainty factors deemed appropriate (RfD = NOAEL/UF).
Where a special FQPA safety factor or the default FQPA safety factor is
used, this additional factor is applied to the RfD by dividing the RfD
by such additional factor. The acute or chronic Population Adjusted
Dose (aPAD or cPAD) is a modification of the RfD to accommodate this
type of safety factor.
For non-dietary risk assessments (other than cancer) the UF is used
to determine the LOC. For example, when 100 is the appropriate UF (10X
to account for interspecies differences and 10X for intraspecies
differences) the LOC is 100. To estimate risk, a ratio of the NOAEL to
exposures (margin of exposure (MOE) = NOAEL/exposure) is calculated and
compared to the LOC.
The linear default risk methodology (Q*) is the primary method
currently used by the Agency to quantify carcinogenic risk. The Q*
approach assumes that any amount of exposure will lead to some degree
of cancer risk. A Q* is calculated and used to estimate risk which
represents a probability of occurrence of additional cancer cases
(e.g., risk). An example of how such a probability risk is expressed
would be to describe the risk as one in one hundred thousand (1 X
10-\5\), one in a million (1 X 10-\6\), or one in
ten million (1 X 10\7\). Under certain specific
circumstances, MOE calculations will be used for the carcinogenic risk
assessment. In this non-linear approach, a ``point of departure'' is
identified below which carcinogenic effects are not expected. The point
of departure is typically a NOAEL based on an endpoint related to
cancer effects though it may be a different value derived from the dose
response curve. To estimate risk, a ratio of the point of departure to
exposure (MOEcancer = point of departure/exposures) is
calculated.
A summary of the toxicological endpoints for penoxsulam used for
human risk assessment is shown in Table 2 of this unit:

[[Page 57192]]

Table 2.--Summary of Toxicological Dose and Endpoints for Penoxsulam for Use in Human Risk Assessment
Exposure Scenario Dose Used in Risk Assessment, UF Special FQPA SF* and Level of Concern for Risk Assessment Study and Toxicological Effects
Acute Dietary (all populations) None
UF = N/A		 Not applicable No toxicological endpoint attributable to a single exposure was identified in the available toxicology studies on penoxsulam.
Chronic Dietary (all populations) NOAEL= 14.7 mg/kg/day
UF = 100
Chronic RfD = 0.147 mg/kg/day. 		Special FQPA SF = 1x
cPAD = chronic RfD
Special FQPA SF = 0.147 mg/kg/day. 		1-Year Chronic Feeding Study in Dogs.
LOAEL = 46.2 mg/kg/day based on multifocal hyperplasia of the pelvic epithelium of the kidney.
Incidental Oral Short-Term (1 - 30 days) NOAEL = 17.8 mg/kg/day Residential LOC for MOE = 100
Occupational = NA		 13-Week Feeding Study
in Dogs.
LOAEL = 49.4 mg/kg/day
based on histopathologic
changes in kidneys

Incidental Oral Intermediate-Term (1 - 6 months) 		NOAEL = 17.8 mg/kg/day Residential LOC for MOE = 100
Occupational = NA		 13-Week Feeding Study
in Dogs.
LOAEL = 49.4 mg/kg/day
based on histopathologic
changes in kidneys.
Dermal Short-Term (1 - 30 days)

None Not applicable No dermal, systemic,
neuro or developmental
toxicity concerns.
Dermal Intermediate-Term (1 - 6 months) Oral study
NOAEL= 17.8 mg/kg/day (dermal absorption rate = 50%). 		Residential LOC for MOE = 100
Occupational LOC for MOE = 100. 		13-Week Feeding Study
in Dogs. (dermal absorption LOAEL = 49.4 mg/kg/day
based on histopathologic
changes in kidneys.
Dermal Long-Term > 6 months) Oral study
NOAEL= 14.7 mg/kg/day (dermal absorption rate = 50%).		 Residential LOC for MOE = 100
Occupational LOC for MOE = 100. 		1-Year Chronic Feeding
Study in Dogs.
LOAEL = 46.2 mg/kg/day
based on multifocal
hyperplasia of the pelvic epithelium of the kidney.
Inhalation Short-Term (1 - 30 days) Oral study
NOAEL= 17.8 mg/kg/day (inhalation absorption rate = 100%).		 Residential LOC for MOE = 100
Occupational LOC for MOE = 100. 		13-Week Feeding Study
in Dogs.
LOAEL = 49.4 mg/kg/day based on histopathologic
changes in kidneys.
Inhalation Intermediate-Term (1 - 6 months) Oral study
NOAEL= 17.8 mg/kg/day (inhalation absorption rate = 100%).		 Residential LOC for MOE = 100
Occupational LOC for MOE = 100. 		13-Week Feeding Study
in Dogs.
LOAEL = 49.4 mg/kg/day based on histopathologic changes in kidneys.
Inhalation Long-Term (> 6 months) Oral study
NOAEL= 14.7 mg/kg/day (inhalation absorption rate = 100%). 		Residential LOC for MOE = 100
Occupational LOC for MOE = 100. 		1-Year Chronic Feeding
Study in Dogs.
LOAEL = 46.2 mg/kg/day
based on multifocal
hyperplasia of the pelvic epithelium of the kidney.

Cancer (oral, dermal, inhalation) 		Suggestive evidence of carcinogenicity, but not sufficient to assess
human carcinogenic potential
UF = uncertainty factor, FQPA SF = Special FQPA safety factor, NOAEL = no observed adverse effect level, LOAEL = lowest observed adverse effect level, PAD = population adjusted dose (a = acute, c = chronic) RfD = reference dose, MOE = margin of exposure, LOC = level of concern, N/A = Not Applicable.


C. Exposure Assessment
1. Dietary exposure from food and feed uses. Tolerances have been
established (40 CFR 180.605) for the residues of penoxsulam, in or on a
variety of raw agricultural commodities. Tolerances are established in/
on rice, grain at 0.02 ppm and rice, straw at 0.5 ppm. Risk assessments
were conducted by EPA to assess dietary exposures from penoxsulam in
food as follows:

i. Acute exposure. Acute dietary 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.
EPA did not identify a treatment-related effect observed in any of
the available toxicity studies on penoxsulam that could be considered
to have resulted from a single dose of the test material.

ii. Chronic exposure. In conducting the chronic dietary risk
assessment EPA used the Lifeline\TM\ Model Version 2.0, which uses food
consumption data as reported by respondents in the 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 chronic exposure
assessments: The chronic dietary analysis for penoxsulam was conducted
using tolerance levels and 100% Crop Treated (CT) for the use on rice.
iii. Cancer. The Agency has classified penoxsulam as Suggestive
Evidence of Carcinogenicity, But not sufficient to assess human
carcinogenic potential and, therefore, quantification of human cancer
risk is not required. The weight-
[[Page 57193]]
of-the-evidence for this classification is as follows:

a. Evidence of carcinogenicity (mononuclear cell leukemia (MNCL))
was seen in one sex (males) of one species (rat).

b. There was an increased incidence of MNCL at all dose levels with
all incidences exceeding the laboratory historical control, however,
the dose-response was flat over a wide range of doses.

c. Although MNCL is recognized as a common neoplasm in Fischer
rats, the mechanism of producing MNCL is not completely understood.
Therefore, the significance of MNCL and its biological relevance for
human cancer risk remains uncertain and cannot be discounted.

d. There is no mutagenicity concern for penoxsulam.

e. SAR data are negative for MNCL.

Note: Although dosing in the male mice was not considered to be
adequate, the Agency concluded that an additional mouse
carcinogenicity study was not required. This was based on the following:
1. No treatment-related effects were seen up to the limit dose
of a 1,000 mg/kg/day in a subchronic mouse study;
2. No hyperplasia was seen in the mouse carcinogenicity study at
350 mg/kg/day in males and 750 mg/kg/day in females;
3. No structural alerts were seen with the SAR data;
4. Rat data indicate saturation of absorption at 250 mg/kg/day;
and
5. No mutagenic activity. Based on these data, the CARC
determined that a repeat of the male mouse cancer study would have
no impact on the regulation of penoxsulam.
iv. Anticipated residue and percent crop treated (PCT) information.
For this analysis the tolerance levels and 100% CT for rice commodities
were used.
2. Dietary exposure from drinking water. The Agency lacks
sufficient monitoring exposure data to complete a comprehensive dietary
exposure analysis and risk assessment for penoxsulam 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 penoxsulam.
The standard models used by EPA in assessing potential high end
pesticide levels in surface water are not designed to address the
agricultural practices involved in rice farming. EPA has recently
developed a Tier I Aquatic Exposure Assessment method of estimating
screening level concentrations in surface water to support regulatory
decisions for pesticides used in rice agriculture that require
ecological and human health risk assessments.
Under this method estimated environmental concentrations (EEC's)
and estimated drinking water concentrations (EDWCs) for the use of
pesticides in rice paddies are estimated by applying the total annual
application to the paddy and partitioning the pesticide between the
water and the paddy sediment according to a linear or Kd
partitioning model. The EEC/EDWC ([mu]g. L-\1\) represents
the dissolved concentration occurring in the water column and the
concentration in water released from the paddy. Movement of pesticide
on suspended sediment is not considered. The equation to use for this
calculation is:
EEC = 10\9\ MT/VT +
msedKd
where MT is the total mass of pesticide in kg applied per ha
of paddy, VT is 1.067 x10\6\ L ha-\1\ which is
the volume of water in a paddy 4 inches (10.16 cm) deep, and includes
the pore space in a 1 cm sediment interaction zone. The mass of
sediment, msed, is the amount found in the top 1 cm
interaction zone and is 130,000 kg ha-\1\ when the sediment
bulk density was assumed to be 1.3 kg L-\1\, a standard
assumption for the bulk density of surface horizons of mineral soils
(Brady, Nyle C. 1984. The Nature and Properties of Soils, Ninth
Edition. Macmillan Publishing Company, New York ; Hillel, Daniel. 1982.
Introduction to Soil Physics. Academic Press. Orlando, Florida). The
10\9\ constant converts the units of mass from kg to [mu]g. For
chemicals that have a valid Koc, the Kd can be
calculated using a sediment carbon content of 2% (Koc*0.02).
An organic carbon content of 2% represents a typical value for a high
clay soil that might be used to grow rice in the Mississippi Valley or
Gulf Coast regions. Both Kd and Koc should be
estimated according to the methods recommended for other surface water
models in EFED's Input Parameter Guidance (USEPA, 2002). References can
be viewed on the EPA Pesticide Site at http://www.epa.gov/oppefed1/
models/water/input_guidance2_28_02.htm.
This model is considered conservative, because the residues
calculated by this method are screening estimates and as such are
expected to exceed the true values found in the environment the great
majority of the time. Based on preliminary assessment of rice
monitoring data, predicted pesticide concentrations as derived above
(assuming a 1 cm sediment interaction zone) exceed the observed peak
pesticide concentrations. These EEC's are expected to exceed the
concentrations measured in the paddy, because degradation processes and
dilution with uncontaminated water outside the paddy is not considered.
This calculation does not represent a concentration expected in
drinking water, as it represents paddy discharge water. Rather, it
represents an upper bound on the drinking water concentrations, and is
therefore suitable for use in screening assessments. The concentrations
found at drinking water facilities impacted by rice culture would be
expected to be less than this value (in some cases much less), because
of the aforementioned degradation processes, dilution by water from
areas in the basin not in rice culture, and the fact that in most cases
less than 100% of the rice paddies in a specific area will be treated
with the pesticide.
Based on the methodology to estimate screening level concentrations
of pesticides in rice and SCI-GROW models, the EECs of penoxsulam for
acute and chronic exposures are estimated to be 45 parts per billion
(ppb) for surface water and 5.86 ppb for combined residues of
penoxsulam in ground 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).
Penoxsulam 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.''
Unlike other pesticides for which EPA has followed a cumulative
risk approach based on a common mechanism of toxicity, EPA has not made
a common mechanism of toxicity finding as to penoxsulam and any other
substances and penoxsulam does not appear to produce a toxic metabolite
produced by other substances. For the purposes of this tolerance
action, therefore, EPA has not assumed that penoxsulam has a common
mechanism of toxicity with other substances. 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
the policy statements released by EPA's OPP concerning common mechanism
determinations and procedures for cumulating effects
[[Page 57194]]
from substances found to have a common mechanism on EPA's web site 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 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. 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 safety
factor value based on the use of traditional uncertainty factors and/or
special FQPA safety factors, as appropriate.
2. Prenatal and postnatal sensitivity. There is no quantitative or
qualitative evidence of susceptibility in rats or rabbits following in
utero exposures. No developmental toxicity was seen at the highest dose
tested in either species. Following pre/post-natal exposure in the two-
generation study, offspring toxicity was seen at the same dose that
induced parental toxicity and was not more severe than maternal toxicity.
3. Conclusion. There is a complete toxicity data base for
penoxsulam and exposure data are complete or are estimated based on
data that reasonably accounts for potential exposures. The uncertainty
factor (UF) is 100 based on 10X for interspecies extrapolation and 10X
for intraspecies variability. EPA determined that the 10X safety factor
(SF) to protect infants and children should be removed based on the
following:
i. There was no toxicologically significant evidence observed of
neurotoxicity in either the acute or chronic neurotoxicity study.
ii. No definitive quantitative or qualitative susceptibility was
observed in either of the developmental rat or rabbit studies.
iii. Significant dose-related effects in the two-generation
reproduction study were limited to the delay in preputial separation.
No other endpoints of reproductive toxicity or offspring growth and
survival were affected by treatment.
iv. The chronic dietary food exposure assessment utilizes proposed
tolerance level residues and 100% CT information for all commodities.
By using these conservative assessments, actual and chronic exposures/
risks will not be underestimated.
v. The dietary drinking water assessment (Tier 1 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
To estimate total aggregate exposure to a pesticide from food,
drinking water, and residential uses, the Agency calculates DWLOCs
which are used as a point of comparison against EECs. DWLOC values are
not regulatory standards for drinking water. DWLOCs are theoretical
upper limits on a pesticide's concentration in drinking water in light
of total aggregate exposure to a pesticide in food and residential
uses. In calculating a DWLOC, the Agency determines how much of the
acceptable exposure (i.e., the PAD) is available for exposure through
drinking water e.g., allowable chronic water exposure (mg/kg/day) =
cPAD - (average food + residential exposure). This allowable exposure
through drinking water is used to calculate a DWLOC.
A DWLOC will vary depending on the toxic endpoint, drinking water
consumption, and body weights. Default body weights and consumption
values as used by the EPA's Office of Water are used to calculate
DWLOCs: 2 liter (L)/70 kg (adult male), 2L/60 kg (adult female), and
1L/10 kg (child). Default body weights and drinking water consumption
values vary on an individual basis. This variation will be taken into
account in more refined screening-level and quantitative drinking water
exposure assessments. Different populations will have different DWLOCs.
Generally, a DWLOC is calculated for each type of risk assessment used:
Acute, short-term, intermediate-term, chronic, and cancer.
When EECs for surface water and ground water are less than the
calculated DWLOCs, OPP concludes with reasonable certainty that
exposures to the pesticide in drinking water (when considered along
with other sources of exposure for which OPP has reliable data) would
not result in unacceptable levels of aggregate human health risk at
this time. Because OPP considers the aggregate risk resulting from
multiple exposure pathways associated with a pesticide's uses, levels
of comparison in drinking water may vary as those uses change. If new
uses are added in the future, OPP will reassess the potential impacts
of residues of the pesticide in drinking water as a part of the
aggregate risk assessment process.
1. Acute risk. A quantitative acute exposure/risk assessment was
not performed, because no treatment-related effect was identified in
any of the available toxicity studies on penoxsulam that could be
considered to have resulted from a single dose of penoxsulam.
Penoxsulam is not expected to pose an acute risk.
2. Chronic risk. Using the exposure assumptions described in this
unit for chronic exposure, EPA has concluded that exposure to
penoxsulam from food will utilize < 1 % of the cPAD for the U.S.
population, < 1 % of the cPAD for all infants (< 1 year old), and < 1 % of
the cPAD for all children (1 - 12). There are no residential uses for
penoxsulam that result in chronic residential exposure to penoxsulam.
In addition, there is potential for chronic dietary exposure to
penoxsulam in drinking water. After calculating DWLOCs and comparing
them to the EECs for surface and ground water, EPA does not expect the
aggregate exposure to exceed 100% of the cPAD, as shown in Table 3 of
this unit:

Table 3.--Aggregate Risk Assessment for Chronic (Non-Cancer) Exposure to Penoxsulam
Population Subgroup cPAD mg/kg/ day % cPAD (Food) Surface Water EEC (ppb),/ CHED> Ground Water EEC (ppb) Chronic DWLOC (ppb)
U.S. Population 0.147 < 1 45 5.86 5,100
All Infants < 1 year old 0.147 < 1 45 5.86 1,500
Children 1-2 years old 0.147 < 1 45 5.86 1,500
Children 3-5 years old 0.147 < 1 45 5.86 1,500
Children 6-12 years old 0.147 < 1 45 5.86 1,500
Youth 13-19 years old 0.147 < 1 45 5.86 1,500
Adults 20-49 years old 0.147 < 1 45 5.86 5,100
Females 13-49 years old 0.147 < 1 45 5.86 4,400
Adults 50+ years old 0.147 < 1 45 5.86 5,100

[[Page 57195]]

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).
Penoxsulam 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).
Penoxsulam 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. Penoxsulam is
classified as Suggestive Evidence of Carcinogenicity, but Not
Sufficient to Assess Human Carcinogenic Potential. A human cancer risk
assessment is not required. A rational for this classification has been
provided in Unit.III.C.1.iii. of this document.
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 penoxsulam residues.
IV. Other Considerations
A. Analytical Enforcement Methodology
An analytical methodology (LC/MS/MS method) has been subjected to
an independent laboratory validation, and will be available for use as
an enforcement method.
Adequate enforcement methodology (using 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 no International Residue Limits for penoxsulam use on rice.
C. Conditions
The modifications recommended by the independent laboratory and
EPA's Analytical Chemistry Branch will be made to the final written
enforcement method.
The final report of the ongoing storage stability study must be
submitted in support of any future food uses. Storage stability data
for future uses will require the receipt and acceptance of the final
rice report as well as any data required for the additional use.
V. Conclusion
Therefore, the tolerance is established for residues of penoxsulam,
2-(2,2-difluoroethoxy)-N-(5,8-dimethoxy[1,2,4]
triazolo[1,5-
c]pyrimidin-2-yl)-6-(trifluoromethyl)benzenesulfonamide, in or on rice,
grain at 0.02 ppm and rice, straw at 0.5 ppm. Separate rice processed
commodity tolerances are not needed. Any residues of penoxsulam, per.
se., in/on rice processed commoditites will be covered by the tolerance
on rice, grain at 0.02 ppm.
VI. Objections and Hearing Requests
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. Although the procedures in those regulations require
some modification to reflect the amendments made to FFDCA by FQPA, EPA
will continue to use those procedures, with appropriate adjustments,
until the necessary modifications can be made. The new section 408(g)
of FFDCA provides essentially the same process for persons to
``object'' to a regulation for an exemption from the requirement of a
tolerance issued by EPA under new section 408(d) of FFDCA, as was
provided in the old sections 408 and 409 of FFDCA. However, the period
for filing objections is now 60 days, rather than 30 days.
A. What Do I Need to Do to File an Objection or Request a Hearing?
You must file your objection or request a hearing on this
regulation in accordance with the instructions provided in this unit
and in 40 CFR part 178. To ensure proper receipt by EPA, you must
identify docket ID number OPP-2004-0286 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 November
23, 2004.
1. Filing the request. Your objection must specify the specific
provisions in the regulation that you object to, and the grounds for
the objections (40 CFR 178.25). If a hearing is requested, the
objections must include a statement of the factual issues(s) on which a
hearing is requested, the requestor's contentions on such issues, and a
summary of any evidence relied upon by the objector (40 CFR 178.27).
Information submitted in connection with an objection or hearing
[[Page 57196]]
request may be claimed confidential by marking any part or all of that
information as CBI. Information so marked will not be disclosed except
in accordance with procedures set forth in 40 CFR part 2. A copy of the
information that does not contain CBI must be submitted for inclusion
in the public record. Information not marked confidential may be
disclosed publicly by EPA without prior notice.
Mail your written request to: Office of the Hearing Clerk (1900L),
Environmental Protection Agency, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460-0001. You may also deliver your request to the
Office of the Hearing Clerk in Suite 350, 1099 14th St., NW.,
Washington, DC 20005. The Office of the Hearing Clerk is open from 8
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The
telephone number for the Office of the Hearing Clerk is (202) 564-6255.
2. Tolerance fee payment. If you file an objection or request a
hearing, you must also pay the fee prescribed by 40 CFR 180.33(i) or
request a waiver of that fee pursuant to 40 CFR 180.33(m). You must
mail the fee to: EPA Headquarters Accounting Operations Branch, Office
of Pesticide Programs, P.O. Box 360277M, Pittsburgh, PA 15251. Please
identify the fee submission by labeling it ``Tolerance Petition Fees.''
EPA is authorized to waive any fee requirement ``when in the
judgement of the Administrator such a waiver or refund is equitable and
not contrary to the purpose of this subsection.'' For additional
information regarding the waiver of these fees, you may contact James
Tompkins by phone at (703) 305-5697, by e-mail at tompkins.jim@epa.gov,
or by mailing a request for information to Mr. Tompkins at Registration
Division (7505C), Office of Pesticide Programs, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-0001.
If you would like to request a waiver of the tolerance objection
fees, you must mail your request for such a waiver to: James Hollins,
Information Resources and Services Division (7502C), Office of
Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania
Ave., NW., Washington, DC 20460-0001.
3. Copies for the Docket. In addition to filing an objection or
hearing request with the Hearing Clerk as described in Unit VI.A., you
should also send a copy of your request to the PIRIB for its inclusion
in the official record that is described in ADDRESSES. Mail your
copies, identified by docket ID number OPP-2004-0286, to: Public
Information and Records Integrity Branch, Information Resources and
Services Division (7502C), Office of Pesticide Programs, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460--
0001. In person or by courier, bring a copy to the location of the
PIRIB described in ADDRESSES. You may also send an electronic copy of
your request via e-mail to: opp-docket@epa.gov. Please use an ASCII
file format and avoid the use of special characters and any form of
encryption. Copies of electronic objections and hearing requests will
also be accepted on disks in WordPerfect 6.1/8.0 or ASCII file format.
Do not include any CBI in your electronic copy. You may also submit an
electronic copy of your request at many Federal Depository Libraries.
B. When Will the Agency Grant a Request for a Hearing?
A request for a hearing will be granted if the Administrator
determines that the material submitted shows the following: There is a
genuine and substantial issue of fact; there is a reasonable
possibility that available evidence identified by the requestor would,
if established resolve one or more of such issues in favor of the
requestor, taking into account uncontested claims or facts to the
contrary; and resolution of the factual issues(s) in the manner sought
by the requestor would be adequate to justify the action requested (40
CFR 178.32).
VII. 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. The Agency hereby certifies that this rule will not
have significant negative economic impact on a substantial number of
small entities. 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 (59 FR 22951,
November 6, 2000). Executive Order 13175, requires EPA to develop an
accountable process to ensure
[[Page 57197]]
``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.
VIII. Congressional Review Act
The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
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: September 17, 2004.
James Jones,
Director, Office of Pesticide Programs.

Therefore, 40 CFR chapter I is amended as follows:
PART 180--[AMENDED]
1. The authority citation for part 180 continues to read as follows:
Authority: 21 U.S.C. 321(q), 346a and 371.
2. Section 180.605 is added to read as follows:
Sec. 180.605 Penoxsulam; tolerances for residues.
(a) General. Tolerances are established for the herbicide,
penoxsulam ( 2-(2,2-difluoroethoxy)-N-(5,8-dimethoxy[1,2,4]
triazolo[1,5-c]pyrimidin-2-yl)-6-(trifluoromethyl)benzenesulfonamide)
in/on the following raw agricultural commodities:
------------------------------------------------------------------------
Commodity Parts per million
------------------------------------------------------------------------
Rice, grain.......................................... 0.02
Rice, straw.......................................... 0.50
------------------------------------------------------------------------
(b) Section 18 emergency exemptions. [Reserved]
(c) Tolerances with regional registrations. [Reserved]
(d) Indirect or inadvertent residues. [Reserved]
[FR Doc. 04-21502 Filed 9-23-04; 8:45 am]
BILLING CODE 6560-50-S