[Federal Register Volume 63, Number 65 (Monday, April 6, 1998)]
[Rules and Regulations]
[Pages 16690-16696]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-9068]


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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: [email protected]. 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: 
[email protected].

 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:
     [email protected].

     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