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Rimsulfuron - Pesticide Tolerance 4/98

[Federal Register: April 6, 1998 (Volume 63, Number 65)]
[Rules and Regulations]
[Page 16690-16696]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr06ap98-13]
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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-300639; FRL-5784-4]
RIN 2070-AB78

Rimsulfuron (N-((4,6-dimethoxypyrimidin-2-yl)aminocarbonyl)-3-
(ethylsulfonyl)-2-pyridinesulfonamide); Pesticide Tolerance

 AGENCY: Environmental Protection Agency (EPA).

 ACTION: Final rule.

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 SUMMARY: This regulation establishes a time limited tolerance for
residues of rimsulfuroron in or on tomatoes. E.I.duPont de Nemours and
Company, Inc. requested this tolerance under the Federal Food, Drug and
Cosmetic Act (FFDCA), as amended by the Food Quality Protection Act of
1996 (Pub. L. 104-70).

 DATES: This regulation is effective April 6, 1998. Objections and
requests for hearings must be received by EPA on or before June 5,
1998.

 ADDRESSES: Written objections and hearing requests, identified by the
docket control number, [OPP-300639], must be submitted to: Hearing
Clerk (1900), Environmental Protection Agency, Rm. M3708, 401 M St.,
SW., Washington, DC 20460. Fees accompanying objections and hearing
requests shall be labeled "Tolerance Petition Fees" and forwarded to:
EPA Headquarters Accounting Operations Branch, OPP (Tolerance Fees),
P.O. Box 360277M, Pittsburgh, PA 15251. A copy of any objections and
hearing requests filed with the Hearing Clerk identified by the docket
control number, [OPP-300639], must also be submitted to: Public
Information and Records Integrity Branch, Information Resources and
Services Division (7502C), Office of Pesticide Programs, Environmental
Protection Agency, 401 M St., SW., Washington, DC 20460. In person,
bring a copy of objections and hearing requests to Rm. 119, CM #2, 1921
Jefferson Davis Hwy., Arlington, VA.
     A copy of objections and hearing requests filed with the Hearing
Clerk may also be submitted electronically by

[[Page 16691]]

sending electronic mail (e-mail) to: opp-docket@epamail.epa.gov. Copies
of objections and hearing requests must be submitted as an ASCII file
avoiding the use of special characters and any form of encryption.
Copies of objections and hearing requests will also be accepted on
disks in WordPerfect 5.1 file format or ASCII file format. All copies
of objections and hearing requests in electronic form must be
identified by the docket control number [OPP-300639]. No Confidential
Business Information (CBI) should be submitted through e-mail.
Electronic copies of objections and hearing requests on this rule may
be filed online at many Federal Depository Libraries.

 FOR FURTHER INFORMATION CONTACT: By mail: Jim Tompkins, Registration
Division [7505C], Office of Pesticide Programs, Environmental
Protection Agency, 401 M St., SW., Washington, DC 20460. Office
location, telephone number, and e-mail address: Crystal Mall #2, 1921
Jefferson Davis Hwy., Arlington, VA, 703-305-5697, e-mail:
tompkins.jim@epamail.epa.gov.

 SUPPLEMENTARY INFORMATION: In the Federal Register of February 20,
1998 (63 FR 8635-8644)(FRL-5768-9), EPA, issued a notice pursuant to
section 408 of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21
U.S.C. 346a(e) announcing the filing of a pesticide petition (PP)
6F4706 for tolerance by E.I. duPont de Nemours and Company, Inc. This
notice included a summary of the petition prepared by E.I. duPont de
Nemours and Company, Inc., the registrant. There were no comments
received in response to the notice of filing.
     The petition requested that 40 CFR 180.478 be amended by
establishing a tolerance for residues of the herbicide rimsulfuron, in
or on tomatoes at 0.1 ppm. During the course of the review the Agency
determined that the data supported a tolerance of 0.05 ppm, therefore,
the Agency is establishing a tolerance of 0.05 ppm in tomatoes.

 I. Risk Assessment and Statutory Findings

     New 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) 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)
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. First, EPA determines the
toxicity of pesticides based primarily on toxicological studies using
laboratory animals. These studies address many adverse health effects,
including (but not limited to) reproductive effects, developmental
toxicity, toxicity to the nervous system, and carcinogenicity. Second,
EPA examines exposure to the pesticide through the diet (e.g., food and
drinking water) and through exposures that occur as a result of
pesticide use in residential settings.

 A. Toxicity

     1.  Threshold and non-threshold effects. For many animal studies,
a dose response relationship can be determined, which provides a dose
that causes adverse effects (threshold effects) and doses causing no
observed effects (the "no-observed effect level" or "NOEL").
     Once a study has been evaluated and the observed effects have been
determined to be threshold effects, EPA generally divides the NOEL from
the study with the lowest NOEL by an uncertainty factor (usually 100 or
more) to determine the Reference Dose (RfD). The RfD is a level at or
below which daily aggregate exposure over a lifetime will not pose
appreciable risks to human health. An uncertainty factor (sometimes
called a "safety factor") of 100 is commonly used since it is assumed
that people may be up to 10 times more sensitive to pesticides than the
test animals, and that one person or subgroup of the population (such
as infants and children) could be up to 10 times more sensitive to a
pesticide than another. In addition, EPA assesses the potential risks
to infants and children based on the weight of the evidence of the
toxicology studies and determines whether an additional uncertainty
factor is warranted. Thus, an aggregate daily exposure to a pesticide
residue at or below the RfD (expressed as 100% or less of the RfD) is
generally considered acceptable by EPA. EPA generally uses the RfD to
evaluate the chronic risks posed by pesticide exposure. For shorter
term risks, EPA calculates a margin of exposure (MOE) by dividing the
estimated human exposure into the NOEL from the appropriate animal
study. Commonly, EPA finds MOEs lower than 100 to be unacceptable. This
hundredfold MOE is based on the same rationale as the hundredfold
uncertainty factor.
     Lifetime feeding studies in two species of laboratory animals are
conducted to screen pesticides for cancer effects. When evidence of
increased cancer is noted in these studies, the Agency conducts a
weight of the evidence review of all relevant toxicological data
including short-term and mutagenicity studies and structure activity
relationship. Once a pesticide has been classified as a potential human
carcinogen, different types of risk assessments (e.g., linear low dose
extrapolations or MOE calculation based on the appropriate NOEL) will
be carried out based on the nature of the carcinogenic response and the
Agency's knowledge of its mode of action.
     2.  Differences in toxic effect due to exposure duration. The
toxicological effects of a pesticide can vary with different exposure
durations. EPA considers the entire toxicity data base, and based on
the effects seen for different durations and routes of exposure,
determines which risk assessments should be done to assure that the
public is adequately protected from any pesticide exposure scenario.
Both short and long durations of exposure are always considered.
Typically, risk assessments include "acute," "short-term,"
"intermediate term," and "chronic" risks. These assessments are
defined by the Agency as follows.
     Acute risk, by the Agency's definition, results from 1-day
consumption of food and water, and reflects toxicity which could be
expressed following a single oral exposure to the pesticide residues.
High end exposure to food and water residues are typically assumed.
     Short-term risk results from exposure to the pesticide for a
period of 1-7 days, and therefore overlaps with the acute risk
assessment. Historically, this risk assessment was intended to address
primarily dermal and inhalation exposure which could result, for
example, from residential pesticide applications. However, since
enaction of FQPA, this assessment has been expanded to include both
dietary and non-dietary sources of exposure, and will typically
consider exposure from food, water, and residential uses when reliable
data are available. In this assessment, risks from average food and
water exposure, and high-end

[[Page 16692]]

residential exposure, are aggregated. High-end exposures from all three
sources are not typically added because of the very low probability of
this occurring in most cases, and because the other conservative
assumptions built into the assessment assure adequate protection of
public health. However, for cases in which high-end exposure can
reasonably be expected from multiple sources (e.g. frequent and
widespread homeowner use in a specific geographical area), multiple
high-end risks will be aggregated and presented as part of the
comprehensive risk assessment/characterization. Since the toxicological
endpoint considered in this assessment reflects exposure over a period
of at least 7 days, an additional degree of conservatism is built into
the assessment; i.e., the risk assessment nominally covers 1-7 days
exposure, and the toxicological endpoint/NOEL is selected to be
adequate for at least 7 days of exposure. (Toxicity results at lower
levels when the dosing duration is increased.)
     Intermediate-term risk results from exposure for 7 days to several
months. This assessment is handled in a manner similar to the short-
term risk assessment.
     Chronic risk assessment describes risk which could result from
several months to a lifetime of exposure. For this assessment, risks
are aggregated considering average exposure from all sources for
representative population subgroups including infants and children.

 B. Aggregate Exposure

     In examining aggregate exposure, FFDCA section 408 requires that
EPA take into account available and reliable information concerning
exposure from the pesticide residue in the food in question, residues
in other foods for which there are tolerances, residues in groundwater
or surface water that is consumed as drinking water, and other non-
occupational exposures through pesticide use in gardens, lawns, or
buildings (residential and other indoor uses). Dietary exposure to
residues of a pesticide in a food commodity are estimated by
multiplying the average daily consumption of the food forms of that
commodity by the tolerance level or the anticipated pesticide residue
level. The Theoretical Maximum Residue Contribution (TMRC) is an
estimate of the level of residues consumed daily if each food item
contained pesticide residues equal to the tolerance. In evaluating food
exposures, EPA takes into account varying consumption patterns of major
identifiable subgroups of consumers, including infants and children.
The TMRC is a "worst case" estimate since it is based on the
assumptions that food contains pesticide residues at the tolerance
level and that 100% of the crop is treated by pesticides that have
established tolerances. If the TMRC exceeds the RfD or poses a lifetime
cancer risk that is greater than approximately one in a million, EPA
attempts to derive a more accurate exposure estimate for the pesticide
by evaluating additional types of information (anticipated residue data
and/or percent of crop treated data) which show, generally, that
pesticide residues in most foods when they are eaten are well below
established tolerances.
     Percent of crop treated estimates are derived from federal and
private market survey data. Typically, a range of estimates are
supplied and the upper end of this range is assumed for the exposure
assessment. By using this upper end estimate of percent of crop
treated, the Agency is reasonably certain that exposure is not
understated for any significant subpopulation group. Further, regional
consumption information is taken into account through EPA's computer-
based model for evaluating the exposure of significant subpopulations
including several regional groups, to pesticide residues. For this
pesticide, the most highly exposed population subgroup was not
regionally based.

 II. Aggregate Risk Assessment and Determination of Safety

     Consistent with 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
rimsulfiuron (N-((4,6-dimethoxypyrimidin-2-yl)aminocarbonyl)-3-
(ethylsulfonyl)-2-pyridinesulfonaminde) and to make a determination on
aggregate exposure, consistent with section 408(b)(2), for tolerances
for residues of rimsulfuron on tomatoes at 0.05 ppm. EPA's assessment
of the dietary exposures and risks associated with establishing the
tolerance follows.

 A. Toxicological Profile

     EPA has evaluated the available toxicity data and considered its
validity, completeness, and reliability as well as the relationship of
the results of the studies to human risk. EPA has also considered
available information concerning the variability of the sensitivities
of major identifiable subgroups of consumers, including infants and
children. The nature of the toxic effects caused by N-(4,6-
dimethoxypyrimidin-2-yl)aminocarbonyl)-3-(ethylsulfonyl)-2-
pyridinesulfonamide) are discussed below.
    1. Several acute toxicology studies placing technical rimsulfuron
in toxicity category III for acute dermal toxicity and primary eye
irritation and toxicity category IV for acute oral toxicity, acute
inhalation toxicity and primary dermal irritation.
    2. A subchronic feeding study in dogs with a no-observed-effect
level (NOEL) of 9.63 milligrams/kilogram/day (mg/kg/day) in males and
10.6 mg/kg/day in females.
    3. A subchronic feeding study in rats with a NOEL of 102 mg/kg/day
in males and 120 mg/kg/day in females.
    4. A rat developmental study with a developmental NOEL of greater
than 6,000 mg/kg/day, the highest dose tested.
    5. A rabbit developmental study with a developmental NOEL of 500
mg/kg/day.
    6. A two-generation rat reproduction study with a reproductive NOEL
of 165 mg/kg/day for males and 264 mg/kg/day for females.
    7. An in vitro gene mutation assay (CHO/HGPRT) with no evidence of
mutagenicity with or without activation.
    8. An in vitro unscheduled DNA synthesis in primary rat hepatocytes
with no DNA damage or induced repair evident.
    9. A mammalian cell cytogenics (Human Lymphocytes) assay--not
clastogenic in human lymphocytes with or without activation.
    10. An in vivo micronucleus assay in mice--did not induce
micronucleated polychromatic erythrocytes.
    11. An in vivo micronucleus test in mice--no significant
differences in the frequency of micronucleated cells were noted in bone
marrow cells.
    12. A 1-year dog feeding study with a NOEL of 1.6 mg/kg/day in
males and 86.5 mg/kg/day in females. Due to questionable biological
significance of the effects at 81.8 mg/kg/day in males, the Heath
Effects Division`s Hazard Identification Assessment Review committee
determined the dose of 81.8 mg/kg/day to be the NOEL only for risk
assessment purposes.
    13. An 18-month mouse chronic feeding/carcinogenicity study with a
NOEL of 351 mg/kg/day in males and 488 mg/kg/day in females for
systemic effects and with no carcinogenic potential observed under
conditions of the study up to 1,127 mg/kg/day in males and 1,505 mg/kg/
day in females, the highest dose tested.
    14. A 2-year rat chronic feeding/carcinogenicity study with a NOEL
of

[[Page 16693]]

11.8 mg/kg/day in males and 163 mg/kg/day in females for systemic
effects and with no carcinogenic potential observed under conditions of
the study up to 414 mg/kg/day in males and 569 mg/kg/day in females,
the highest dose tested.
    Based on a NOEL of 81.8 mg/kg/day in the 1-year dog feeding study
and a safety factor of 100, the reference dose (RfD) has been set at
0.818 mg/kg/day. This tolerance plus the existing tolerances have a
theoretical maximum residue contribution of 0.00452 mg/kg/day and would
utilize less than 0.19% of the reference dose (RfD) for children 1-6
years old. There are no population subgroups for which the percentage
of the RfD utilized is greater than for children 1-6 years old.

B. Toxicological Endpoints

     1.  Acute toxicity. No toxicological effects attributable to a
single exposure (dose) were identified in any of the studies.
Therefore, this risk assessment is not required.
     2.  Short- and intermediate-term toxicity. EPA has concluded that
available evidence doe not indicate any evidence of significant
toxicity from short and intermediate term exposure.
     3. Chronic toxicity. EPA has established the RfD for N-((4,6-
dimethyloxypyrimidin-2-yl)aminocarbonyl)-3-(ethylsulfonyl)-2-
pyridinesulfonamide at 0.818 mg/kg/day. This RfD is based on the
systemic NOEL of 81.8 mg/kg/day for males in a 1-year toxicity study in
beagle dogs.
     4.  Carcinogenicity. On July 29, 1994 the HED RfD/ Peer Review
classified rimsulfuron as a "Group E" chemical. The HED Hazard
Identification Assessment Review Committee (HIARC) classified
rimsulfuron as "not likely" human carcinogen according to EPA
Proposed Guidelines for Carcinogen Risk Assessment (April 10, 1996).

 C. Exposures and Risks

     1. From food and feed uses. Tolerances have been established (40
CFR 180.478) for the residues of rimsulfuron, in or on corn, field,
fodder; corn, field, forage; corn, field, grain; and potato, tubers at
0.1 ppm. The petitioner has proposed a tolerance of 0.1 ppm for
tomatoes. The Agency has determined that a tolerance of 0.05 ppm is
appropriate. Risk assessments were conducted by EPA to assess dietary
exposures and risks from N-((4,6-dimethoxypyrimidin-2-
yl)aminocarbonyl)-3-(ethylsulfonyl)-2-pyridinesulfonamide as follows:
    i.  Acute exposure and risk. 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 1 day or single exposure. An acute risk assessment is not required
as the available studies did not indicate any evidence of significant
toxicity from acute exposure.
     ii.  Chronic exposure and risk. In conducting this chronic dietary
risk assessment, the Agency has made very conservative assumptions--
100% of tomatoes and all other commodities having rimsulfuron
tolerances will contain rimsulfuron residues and those residues will be
at the level of the tolerance. These assumptions will result is an
overestimate of dietary exposure.
    Thus, in making a safety determination for this tolerance, the
Agency is taking into account this conservative exposure assessment.
    The existing tolerances (published and pending) result in a
Theoretical Maximum Residue Contribution (TMRC) that is equivalent to
less than 1% of the RfD for the U.S. population (48 states). There are
no population subgroups for which the percentage of the RfD occupied is
greater than that occupied by the subgroup U.S. population (48 states).
     2.  From drinking water-- Chronic exposure and risk. Based on the
chronic dietary (food) exposure and using default body weights and
water consumption figures, chronic levels of concern (LOC) for
rimsulfuron in drinking water were calculated. For chronic exposure,
based on an adult body weight of 70 kg and consumption of 2 liters of
water per day, the Agency's level of concern from chronic exposure in
drinking water is 29,000 parts per billion (ppb) for adults. For
children (10 kg and consuming 1 liter of water per day) the level of
concern for drinking water is 8,200 ppb.
    Because all the Agency's estimates for the levels of rimsulfuron in
drinking water were less than 2 ppb, potential residues in drinking
water are not greater than the Agency's level of concern.
     3.  From non-dietary exposure. There is no non-food use of
rimsulfuron currently registered under the Federal Insecticide,
Fungicide and Rodenticide Act, as amended. No non-dietary exposures are
expected for the general population.
     4.  Cumulative exposure to substances with common mechanism of
toxicity. Section 408(b)(2)(D)(v) 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." The Agency believes that "available
information" in this context might include not only toxicity,
chemistry, and exposure data, but also scientific policies and
methodologies for understanding common mechanisms of toxicity and
conducting cumulative risk assessments. For most pesticides, although
the Agency has some information in its files that may turn out to be
helpful in eventually determining whether a pesticide shares a common
mechanism of toxicity with any other substances, EPA does not at this
time have the methodologies to resolve the complex scientific issues
concerning common mechanism of toxicity in a meaningful way. EPA has
begun a pilot process to study this issue further through the
examination of particular classes of pesticides. The Agency hopes that
the results of this pilot process will increase the Agency's scientific
understanding of this question such that EPA will be able to develop
and apply scientific principles for better determining which chemicals
have a common mechanism of toxicity and evaluating the cumulative
effects of such chemicals. The Agency anticipates, however, that even
as its understanding of the science of common mechanisms increases,
decisions on specific classes of chemicals will be heavily dependent on
chemical specific data, much of which may not be presently available.
     Although at present the Agency does not know how to apply the
information in its files concerning common mechanism issues to most
risk assessments, there are pesticides as to which the common mechanism
issues can be resolved. These pesticides include pesticides that are
toxicologically dissimilar to existing chemical substances (in which
case the Agency can conclude that it is unlikely that a pesticide
shares a common mechanism of activity with other substances) and
pesticides that produce a common toxic metabolite (in which case common
mechanism of activity will be assumed).
     EPA does not have, at this time, available data to determine
whether N-((4,6-dimethoxypyrimidin-2-yl)aminocarbonyl)-3-
(ethylsulfonyl)-2-pyridinesulfonamide) has a common mechanism of
toxicity with other substances or how to include this pesticide in a
cumulative risk assessment. Unlike other pesticides for which EPA has
followed a cumulative risk approach based on a common mechanism of
toxicity, N-(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl)-3-
(ethylsulfonyl)-2-pyridinesulfonamide) does not appear

[[Page 16694]]

to produce a toxic metabolite produced by other substances. For the
purposes of this tolerance action, therefore, EPA has not assumed that
N-(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl)-3-(ethylsulfonyl)-2-
pyridinesulfonamide has a common mechanism of toxicity with other
substances.

 D. Aggregate Risks and Determination of Safety for U.S. Population

     1.  Acute risk. An acute risk assessment is not required as the
available studies did not indicate any evidence of significant toxicity
from acute exposure.
     2.  Chronic risk. Using the TMRC exposure assumptions described in
Unit II. C. of this preamble, EPA has concluded that aggregate exposure
to N-((4,6-dimethoxypyrimidin-2-yl)aminocarbonyl)-3-(ethylsulfonyl)-2-
pyridinesulfonamide from food will utilize < 1% of the RfD for the U.S.
population. EPA generally has no concern for exposures below 100% of
the RfD because the RfD represents the level at or below which daily
aggregate dietary exposure over a lifetime will not pose appreciable
risks to human health. Despite the potential for exposure to N-((4,6-
dimethoxypyrimidin-2-yl)aminocarbonyl)-3-(ethylsulfonyl(-2-
pyridinesulfoonamide in drinking water, EPA does not expect the
aggregate exposure to exceed 100% of the RfD. EPA concludes that there
is a reasonable certainty that no harm will result from aggregate
exposure to N-((4,6-dimethoxypyrimidin-2-yl)aminocarbonyl)-3-
(ethylsulfonyl)-2-pyridinesulfonamide residues.
     3.  Short- and intermediate-term risk. Short- and intermediate-
term aggregate exposure takes into account chronic dietary food and
water (considered to be a background exposure level) plus indoor and
outdoor residential exposure. A short and intermediate-term risk
assessment is not required as available studies did not indicate any
evidence of significant toxicity from short or intermediate-term
exposure.

 E. Aggregate Cancer Risk for U.S. Population

     EPA concludes that rimsulfuron does not pose a carcinogenic risk
as available studies did not provide any evidence of carcinogenicity
for rimsulfuron.

 F. Aggregate Risks and Determination of Safety for Infants and
Children

     1. Safety factor for infants and children--i. In general. In
assessing the potential for additional sensitivity of infants and
children to residues of N-((4,6-dimethoxypyrimidin-2-yl)aminocarbonyl)-
3-(ethylsulfonyl)-2-pyridinesulfonamide, EPA considered data from
developmental toxicity studies in the rat and rabbit and a two-
generation reproduction study in the rat. The developmental toxicity
studies are designed to evaluate adverse effects on the developing
organism resulting from maternal pesticide exposure gestation.
Reproduction studies provide information relating to effects from
exposure to the pesticide on the reproductive capability of mating
animals and data on systemic toxicity.
     FFDCA section 408 provides that EPA shall apply an additional
tenfold margin of safety for infants and children in the case of
threshold effects to account for pre-and post-natal toxicity and the
completeness of the database unless EPA determines 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. EPA believes that reliable data support using the standard
uncertainty factor (usually 100 for combined inter- and intra-species
variability)) and not the additional tenfold MOE/uncertainty factor
when EPA has a complete data base under existing guidelines and when
the severity of the effect in infants or children or the potency or
unusual toxic properties of a compound do not raise concerns regarding
the adequacy of the standard MOE/safety factor.
    ii.  Developmental and Reproductive toxicity studies.  The prenatal
developmental toxicity data demonstrated no indication of increased
sensitivity of rabbits to in utero exposure to rimsulfuron. In
addition, the multigeneration reproduction study data did not identify
any increased sensitivity of rats to in utero or postnatal exposure. In
both studies, the maternal LOEL was less than or equivalent to the NOEL
for effects in the offspring.
    For chronic dietary risk assessment, the Agency determined the 10x
factor to account for enhanced sensitivity of infants and children (as
required by FQPA) should be removed. Removal of the 10X is based on a
complete database. The present UF of 100 (10X each for inter-and intra-
species variability) is adequate to ensure protection of these
population subgroups from exposure to rimsulfuron for reasons stated
below:
    a. There is no indication of increased sensitivity to young animals
following pre- and/or post-natal exposure to rimsulfuron.
    b. There is no increased sensitivity to fetuses as compared to
maternal animals following in utero exposures in rats and rabbits.
    c. There is no increased sensitivity to pups as compared to adults
in a multi-generation reproduction toxicity study in rats.
    d. Considering the overall toxicity profile of rimsulfruon, it was
noted that toxic effects were only observed at or near the Limit Dose
with all short- and long-term studies.
     2.  Acute risk. EPA has concluded that there is reasonable
certainity of no harm from acute exposure as the available studies did
not indicate any evidence of significant toxicity from acute exposure.
     3.  Chronic risk. Using the conservative exposure assumptions
described above, EPA has concluded that aggregate exposure to N-((4,6-
dimethoxypyrimidin-2-yl)aminocarbonyl)-3-(ethylsulfonyl)-2-
pyridinesulfonamide from food will utilize < 1% of the RfD for infants
and children. EPA generally has no concern for exposures below 100% of
the RfD because the RfD represents the level at or below which daily
aggregate dietary exposure over a lifetime will not pose appreciable
risks to human health. Despite the potential for exposure to N-((4,6-
dimethoxpyrimidin-2-yl)aminocarbonyl)-3-(ethylsulfonyl)-2-
pyridinesulfonamide in drinking water, EPA does not expect the
aggregate exposure to exceed 100% of the RfD. EPA concludes that there
is a reasonable certainty that no harm will result to infants and
children from aggregate exposure to N-((4,6-dimethoxypyrimidin-2-
yl)aminocarbonyl)-3-(ethylsulfonyl)-2-pyridinesulfonamide residues.
     4.  Short- or intermediate-term risk. EPA has concluded that there
is reasonable certainity of no harm from short or intermediate-term
exposure as the available studies did not indicate any evidence of
significant toxicity from such exposure.

 III. Other Considerations

 A. Metabolism in Plants and Animals

     The Agency has concluded that only rimsulfuron needs to be
regulated and assessed for dietary assessment in tomatoes. The Agency
has previously concluded that the nature of the residue in corn and
potatoes is adequatly understood. Metabolism of rimsulfuron proceeds
primarily by two pathways:
    1. Contraction of the sulfonylurea bridge resulting in the
formation of IN-70941 and minor amounts of IN-70942 is the major route;
and,

[[Page 16695]]

    2. Hydrolysis (cleavage) of the sulfonylurea bridge to yield IN-
J290 and IN-E9260 is the minor route.
    The nature of the residue in animals is adequately understood based
on acceptable ruminant and poultry metabolism studies. The two pathways
of E9636 metabolism in ruminants and poultry are consistent with those
demonstrated in field corn, and potatoes.

 B. Analytical Enforcement Methodology

     An adequate analytical method, high-pressure liquid chromatography
using a UV detector, is available for enforcement purposes. The
analytical method for enforcing these tolerances has been submitted for
publication in the Pesticide Analytical Manual, Vol II (PAM II).
Because of the long lead time from establishing these tolerances to
publication of the enforcement methodology in PAM, the analytical
methodology is being made available in the interim to anyone interested
in pesticide enforcement when requested from: Calvin Furlow, Public
Information and Records Integrity Branch, Information Resources and
Services Division (7502C), Office of Pesticide Programs, Environmental
Protection Agency, 401 M St., SW., Washington, DC 20460. Office
location and telephone number: Rm. 119, CM #2, 1921 Jefferson Davis
Highway, Arlington, VA 22202, (703-305-5973).

 C. Magnitude of Residues

     Based on available field trial results, the appropriate tolerance
level for rimsulfuron residues in or on tomatoes is 0.05 ppm, and no
tolerances for rimsulfuron residues are required for tomato processed
commodities.

 D. International Residue Limits

     There are no established CODEX, Canadian or Mexican residue limits
for rimsulfuron in or tomatoes. Thus, harmonization of the proposed
tolerances with CODEX, Canada and Mexico are not an issue for these
petitions.

 E. Rotational Crop Restrictions

     No tolerances for inadvertent residues of rimsulfuron are required
in rotational crops. The rotational crop restrictions contained on the
proposed Shadeout label (EPA 352-556) are adequate.

 IV. Conclusion

     Therefore, the tolerance is established for residues of
rimsulfuron in/or on tomatoes at 0.05 ppm.

 V. Objections and Hearing Requests

     The new FFDCA section 408(g) provides essentially the same process
for persons to "object" to a tolerance regulation issued by EPA under
new section 408(e) and (l)(6) as was provided in the old section 408
and in section 409. However, the period for filing objections is 60
days, rather than 30 days. EPA currently has procedural regulations
which govern the submission of objections and hearing requests. These
regulations will require some modification to reflect the new law.
However, until those modifications can be made, EPA will continue to
use those procedural regulations with appropriate adjustments to
reflect the new law.
     Any person may, by June 5, 1998, file written objections to any
aspect of this regulation and may also request a hearing on those
objections. Objections and hearing requests must be filed with the
Hearing Clerk, at the address given above (40 CFR 178.20). A copy of
the objections and/or hearing requests filed with the Hearing Clerk
should be submitted to the OPP docket for this rulemaking. The
objections submitted must specify the provisions of the regulation
deemed objectionable and the grounds for the objections (40 CFR
178.25). Each objection must be accompanied by the fee prescribed by 40
CFR 180.33(i). If a hearing is requested, the objections must include a
statement of the factual issues on which a hearing is requested, the
requestor's contentions on such issues, and a summary of any evidence
relied upon by the requestor (40 CFR 178.27). A request for a hearing
will be granted if the Administrator determines that the material
submitted shows the following: There is 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 in the manner sought by the requestor would be adequate
to justify the action requested (40 CFR 178.32). Information submitted
in connection with an objection or hearing 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.

 VI. Public Docket and Electronic Submissions

     EPA has established a record for this rulemaking under docket
control number [OPP-300639] (including any comments and data submitted
electronically). A public version of this record, including printed,
paper versions of electronic comments, which does not include any
information claimed as CBI, is available for inspection from 8:30 a.m.
to 4 p.m., Monday through Friday, excluding legal holidays. The public
record is located in Room 119 of the Public Information and Records
Integrity Branch, Information Resources and Services Division (7502C),
Office of Pesticide Programs, Environmental Protection Agency, Crystal
Mall #2, 1921 Jefferson Davis Highway, Arlington, VA.
     Electronic comments may be sent directly to EPA at:
     opp-docket@epamail.epa.gov.

     Electronic comments must be submitted as an ASCII file avoiding
the use of special characters and any form of encryption.
     The official record for this rulemaking, as well as the public
version, as described above will be kept in paper form. Accordingly,
EPA will transfer any copies of objections and hearing requests
received electronically into printed, paper form as they are received
and will place the paper copies in the official rulemaking record which
will also include all comments submitted directly in writing. The
official rulemaking record is the paper record maintained at the
Virginia address in "ADDRESSES" at the beginning of this document.

 VII. Regulatory Assessment Requirements

     This final rule establishes tolerances under FFDCA section 408(d)
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). 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) (Pub. L.
104-4). Nor does it require any prior consultation as specified by
Executive Order 12875, entitled Enhancing the

[[Page 16696]]

Intergovernmental Partnership (58 FR 58093, October 28, 1993), or
special considerations as required by Executive Order 12898, entitled
Federal Actions to Address Environmental Justice in Minority
Populations and Low-Income Populations (59 FR 7629, February 16, 1994),
or require OMB review in accordance with Executive Order 13045,
entitled Protection of Children from Environmental Health Risks and
Safety Risks (62 FR 19885, April 23, 1997).
     In addition, since these tolerances and exemptions that are
established on the basis of a petition under FFDCA section 408(d), such
as the tolerances 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. Nevertheless, the Agency has
previously assessed whether establishing tolerances, exemptions from
tolerances, raising tolerance levels or expanding exemptions might
adversely impact small entities and concluded, as a generic matter,
that there is no adverse economic impact. The factual basis for the
Agency's generic certification for tolerance actions published on May
4, 1981 (46 FR 24950) and was provided to the Chief Counsel for
Advocacy of the Small Business Administration.

 VIII. Submission to Congress and the General Accounting Office

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Bussiness 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 oher
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 the rule in the Federal Register. This 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: April 1, 1998.

James Jones,

Director, Registration Division, 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. 346a and 371.

     2. Section 180.478 is revised to read as follows:

 Sec. 180.478   Rimsulfuron; tolerances for residues

     (a) General.  Tolerances are established for residues of the
herbicide rimsulfuron (N-((4,6-dimethoxypyrimidin-2-yl)aminocarbonyl)-
3-(ethylsulfonyl)-2-pyridinesulfonamide in or on the following raw
agricultural commodities:

------------------------------------------------------------------------
                                                               Parts per

                          Commodity                             million
------------------------------------------------------------------------
Corn, field, fodder.........................................        0.1
Corn, field, forage.........................................        0.1
Corn, field, grain..........................................        0.1
Potatoes, tubers............................................        0.1
 Tomatoes...................................................        0.05
------------------------------------------------------------------------

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

 [FR Doc. 98-9068 Filed 4-2-98; 1:56 pm]
 BILLING CODE 6560-50-F