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Metsulfuron Methyl - Pesticide Tolerance 7/02

ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-2002-0160; FRL-7189-2]
Metsulfuron Methyl; Pesticide Tolerance
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes a tolerance for combined residues
of metsulfuron methyl and its metabolite methyl 2-[[[[(4-methoxy-6-
methyl-1,3,5-triazin-2-yl)amino]carbonyl]amino]sulfonyl]-4-
hydroxbenzoate in or on sorghum, grain, grain at 0.1 part per million
(ppm); sorghum, grain, forage and sorghum, grain, stover at 0.2 ppm.
E.I. DuPont de Nemours & Company 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 August 7, 2002. Objections and
requests for hearings, identified by docket ID number OPP-2002-0160,
must be received on or before October 7, 2002.

ADDRESSES: Written objections and hearing requests may be submitted by
mail, in person, or by courier. Please follow the detailed instructions
for each method as provided in Unit VI. of the SUPPLEMENTARY
INFORMATION. To ensure proper receipt by EPA, your objections and
hearing requests must identify docket ID number OPP-2002-0160 in the
subject line on the first page of your response.

FOR FURTHER INFORMATION CONTACT: By mail: James A. Tompkins,
Registration Division (7505C), Office of Pesticide Programs,
Environmental Protection Agency, 1200 Pennsylvania Ave.,
NW.,Washington, DC 20460; telephone number: (703) 305-5697; e-mail
address: Tompkins.jim@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

    You may be affected by this action if you are an agricultural
producer, food manufacturer, or pesticide manufacturer. Potentially
affected categories and entities may include, but are not limited to:

------------------------------------------------------------------------
                                                          Examples of
           Categories                 NAICS Codes         Potentially
                                                       Affected Entities
------------------------------------------------------------------------
Industry                          111                 Crop production
                                  112                 Animal production
                                  311                 Food manufacturing
                                  32532               Pesticide
                                                       manufacturing
------------------------------------------------------------------------

    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 the table could also be
affected. The North American Industrial Classification System (NAICS)
codes have been provided to assist you and others in determining
whether or not this action might apply to certain entities. If you have
questions regarding the applicability of this action to a particular
entity, consult the person listed under FOR FURTHER INFORMATION
CONTACT.

B. How Can I Get Additional Information, Including Copies of this
Document and Other Related Documents?

    1. Electronically. You may obtain electronic copies of this
document, and certain other related documents that might be available
electronically, from the EPA Internet Home Page at http://www.epa.gov/.
To access this document, on the Home Page select "Laws and
Regulations", "Regulations and Proposed Rules," and then look up the
entry for this document under the "Federal Register--Environmental
Documents." You can also go directly to the Federal Register listings
at http://www.epa.gov/fedrgstr/. A frequently updated electronic
version of 40 CFR part 180 is available at http://www.access.gpo.gov/
nara/cfr/cfrhtml_00/Title_40/40cfr180_00.html, a beta site currently
under development. To access the OPPTS Harmonized Guidelines referenced
in this document, go directly to the guidelines at
http://www.epa.gov/opptsfrs/home/guidelin.htm.
    2. In person. The Agency has established an official record for
this action under docket ID number OPP-2002-0160. The official record
consists of the documents specifically referenced in this action, and
other information related to this action, including any information
claimed as Confidential Business Information (CBI). This official
record includes the documents that are physically located in the
docket, as well as the documents that are referenced in those
documents. The public version of the official record does not include
any information claimed as CBI. The public version of the official
record, which includes printed, paper versions of any electronic
comments submitted during an applicable comment period is available for
inspection in the Public Information and Records Integrity Branch
(PIRIB), Rm. 119, Crystal Mall #2, 1921 Jefferson Davis Hwy.,
Arlington, VA, from 8:30 a.m. to 4 p.m., Monday through Friday,
excluding legal holidays. The PIRIB telephone number is (703) 305-5805.

II. Background and Statutory Findings

    In the Federal Register of March 19, 1998 (63 FR 13401) (FRL-5776-
7), EPA issued a notice pursuant to section 408 of FFDCA, 21 U.S.C.
346a, as amended by FQPA (Public Law 104-170), announcing the filing of
a pesticide petition (PP 3F4215) by E.I. du Pont de Nemours & Company,
Agricultural Products, P. O. Box 80038, Wilmington, DE 19880-0038. This
notice included a summary of the petition prepared by E.I. Du Pont de
Nemours & Company, the registrant. There were no comments received in
response to the notice of filing.
    The petition requested that 40 CFR 180.428 be amended by
establishing tolerances for combined residues of the herbicide
metsulfuron methyl, methyl-2-[[[[ (4-methoxy-6- methyl-1,3,5-triazin-
2-yl)amino]carbonyl]amino]sulfonyl] benzoate, in or on sorghum grain
at 0.1 ppm, sorghum forage at 0.2 ppm, and sorghum fodder at 0.2 ppm.
Since the publication of the notice of filing, the name and address of
the registrant has changed to E.I. DuPont de Nemours and Company, Crop
Protection, Stine-Haskell Research Center, P.O. Box 30, Newark, DE
19714-0030. During the course of the review, the Agency determined the
commodity listing for grain sorghum should be defined as sorghum,
grain, forage; sorghum, grain, grain; and sorghum, grain, stover. The
Agency also determined that the metabolite, methyl-2-[[[[ (4-methoxy-6-
methyl-1,3,5-triazin- 2-yl)amino] carbonyl]amino] sulfonyl]-4-
hydroxybenzoate should be included in the tolerance expression for the
sorghum, grain commodities. The Agency is also removing the time-
limited tolerances established under paragraph b for sorghum, fodder at
0.5 ppm, sorghum, forage at 0.3 ppm, and sorghum, grain at 0.4 ppm,
since these will be replaced by these tolerances.
    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. For further discussion of the
regulatory requirements of section 408 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), 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), for tolerances for combined residues of metsulfuron methyl
(methyl 2-[[[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]
carbonyl]amino]sulfonyl]benzoate) and its metabolite methyl 2-[[[[(4-
methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl]amino]sulfonyl]-4-
hydroxybenzoate on sorghum, grain, forage at 0.2 ppm; sorghum, grain,
grain at 0.1 ppm; and sorghum, grain, stover at 0.2 ppm. EPA's
assessment of exposures and risks associated with establishing the
tolerance follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its
validity, completeness, and reliability as well as the relationship of
the results of the studies to human risk. EPA has also considered
available information concerning the variability of the sensitivities
of major identifiable subgroups of consumers, including infants and
children. The nature of the toxic effects caused by metsulfuron methyl
are discussed in the following Table 1 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 rodents NOAEL = 68/64 (M/F) milligrams/kilograms/day (mg/kg/day)
LOAEL = 521/659 (M/F) mg/kg/day based on transient decreases
in body weight gain.
870.3200 21–Day dermal toxicity dermal NOAEL = 125 mg/kg/day
dermal LOAEL = 500 mg/kg/day based on skin lesions characterized
by diffuse/multifocal dermatitis.
systemic NOAEL: 125 mg/kg/day
systemic LOAEL: 500 mg/kg/day based on increased incidence
of diarrhea.
870.3700a Prenatal developmental in rodents Maternal NOAEL = 250 mg/kg/day
LOAEL = 1,000 mg/kg/day based on salivation and decreased
body weight gain-compensatory increase after
dosing stopped.
Developmental NOAEL = 1,000 mg/kg/day highest dose tested
(HDT)
LOAEL > 1000 mg/kg/day HDT.
870.3700b Prenatal developmental in nonrodents Maternal NOAEL = 25 mg/kg/day
LOAEL = 1,000 mg/kg/day based on increased mortality, decreased
body weight gains, and clinical signs of anorexia,
red/orange urine and /or exudate.
Developmental NOAEL = 700 mg/kg/day HDT
LOAEL > 700 mg/kg/day HDT.
870.3800 Reproduction and fertility effects Parental/Systemic NOAEL = 34/43(M/F) mg/kg/day
LOAEL = 342/475 (M/F) mg/kg/day based on decreased
premating body weight gains by F0 males and females.
Reproductive NOAEL = 342/475 (M/F) mg/kg/day HDT
LOAEL > 342/475 (M/F) mg/kg/day HDT.
Offspring NOAEL = 342/475 (M/F) mg/kg/day HDT
LOAEL = 342/475 (M/F) mg/kg/day HDT.
870.4100a Chronic toxicity rodents NOAEL = 25 (M/F) mg/kg/day
LOAEL = 250 (M/F) mg/kg/day based on decreased body
weight and body weight gain.
870.4100b Chronic toxicity dogs NOAEL = 125 (M/F) mg/kg/day HDT
LOAEL = not determined
870.4200 Carcinogenicity rats NOAEL = 25 (M/F) mg/kg/day
LOAEL = 250 (M/F) mg/kg/day based on decreased body
weight and body weight gain.
(no) evidence of carcinogenicity
870.4300 Carcinogenicity mice NOAEL = 666/836 (M/F) mg/kg/day HDT
LOAEL = not determined
(no) evidence of carcinogenicity
870.5100 Gene Mutation Salmo nella
typhimurium
, Ames Test
Not mutagenic under the conditions of this study
870.5375 Cytogenetics In vitro mammalian
chromosome aberrations-CHO cells
(2 studies)
Metsulfuron methyl is not a clastogen under the conditions of
this study.
870.5385 In vivo mammalian chromosome aberrations-
rat bone marrow
Metsulfuron methyl did not induce a significant increase in
chromosome aberrations in bone marrow cells when compared
to the vehicle control group.
870.5395 In vivo mammalian cytogenicsmicronucleusassay
in mice
Metsulfuron methyl is negative at the limit dose for
clastogenic activity in the micronucleus assay in bone marrow
cells.
870.5550 Other Effects UDS assay in primary
rat hepatocytes/ mammalian cell
culture
Metsulfuron methyl tested negatively for UDS in mammalian
hepatocytes in vivo
B. Toxicological Endpoints

    The dose at which 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 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 intra
species differences.
    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 the
appropriate UF (RfD = NOAEL/UF). Where an additional safety factor is
retained due to concerns unique to the FQPA, 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 FQPA 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 is expressed as 1 x 10-6 or one in a million).
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 (MOE-cancer ≤
point of departure/exposures) is calculated. A summary of the
toxicological endpoints for metsulfuron methyl used for human risk
assessment is shown in the following Table 2:
Table 2.--Summary of Toxicological Dose and Endpoints for metsulfuron methyl for Use in Human Risk Assessment
Exposure Scenario
Dose Used in Risk Assessment,
UF
FQPA SF* and Level of
Concern for Risk Assessment
Study and Toxicological Effects
Acute Dietary general population including infants and children NA NA An endpoint attributable to a single dose was not identified.
Quantitation of acute dietary risk is not appropriate
Chronic Dietary all populations NOAEL= 25 mg/kg/day
UF = 100
Chronic RfD = 0.25 mg/kg/
day
FQPA SF = 1
cPAD = 0.25 mg/kg/day
Chronic/oncogenicity study in the rat
LOAEL = 250 mg/kg/day based on decreased
body weight and body weight gain.
Short- and Intermediate-Term
Incidental Oral (1 to 30 days
and 1 month to 6 months)
(Residential)
NOAEL=34 mg/kg/day LOC for MOE = 100 (Residential) 2–generation reproduction study in rats based on decreased premating (F0) body weights in male and female rats; systemic effects were seen up to 13 weeks at the LOAEL of 342 mg/kg/day.
Short-, Intermediate-, and Long-
Term Dermal (1 to 30 days; 1 month to 6 months; and > 6 months) (Residential)
NOAEL= 125 mg/kg/day LOC for MOE = 100 (Residential) 21–day dermal toxicity in rabbits based on an
increased incidence of diarrhea in rabbits at
the LOAEL of 500 mg/kg/day.
Short- and Intermediate-
TermInhalation (1 to 30 days
and 1 month to 6 months)
(Residential)
oral study NOAEL= 34 mg/
kg/day (inhalation absorption rate
= 100%)
LOC for MOE = 100 (Residential) 2–generation reproduction study in rats
LOAEL = 342 mg/kg/day based on decreased
body weights in premating (F0) animals for
up to 13 weeks.
Long-Term Inhalation (6 months
to lifetime) (Residential)
oral study NOAEL = 25 mg/
kg/day (inhalation absorption rate
= 100%)
LOC for MOE = 100 (Residential) Chronic/oncogenicity study in the rat
LOAEL = 250 mg/kg/day based on decreased
body weight and body weight gain.
Cancer (oral, dermal, inhalation)
- not likely to be carcinogenic.

 

* The reference to the FQPA Safety Factor refers to any additional safety factor retained due to concerns unique to the FQPA.
C. Exposure Assessment

    1. Dietary exposure from food and feed uses. Tolerances have been
established (40 CFR 180.428) for the combined residues of metsulfuron
methyl and its metabolite methyl 2-[[[[(4-methoxy-6-methyl-1,3,5-
triazin-2- yl)amino]carbonyl]amino]sulfonyl]-4-hydroxybenzoate, in or
on a variety of raw agricultural commodities. Tolerances have been
established for residues of metsulfuron methyl on fat, meat, and meat
byproducts of cattle, goats, hogs, horses, and sheep at 0.1 ppm; kidney
of cattle, goats, hogs, horse, and sheep at 0.5 ppm, and milk at 0.05
ppm. Risk assessments were conducted by EPA to assess dietary exposures
from metsulfuron methyl 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. No acute dietary endpoint attributable to a single
dose was identified. Therefore, quantification of acute dietary risk
was not performed.
    ii. Chronic exposure. In conducting this chronic dietary risk
assessment the Dietary Exposure Evaluation Model (DEEM)
analysis evaluated the individual food consumption as reported by
respondents in the USDA 1989-1992 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: Tolerance residue levels, 100% crop treated (CT)
for all commodities, and DEEM defaults for all processing
factors. In addition, the chemical iodosulfuron methyl recently
received a favorable recommendation for tolerances on corn, field,
grain at 0.03 ppm, and corn, field, stover and forage at 0.05 ppm.
Since the major metabolite of iodosulfuron methyl is metsulfuron
methyl, these tolerances were included in the dietary exposure
assessment.
    iii. Cancer. Since metsulfuron methyl has been classified as "Not
likely to be a human carcinogen", a cancer risk assessment was not
performed.
    2. Dietary exposure from drinking water. The Agency lacks
sufficient monitoring exposure data to complete a comprehensive dietary
exposure analysis and risk assessment for metsulfuron methyl 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 metsulfuron methyl.
    The Agency uses the First Index Reservoir Screening Tool (FIRST) or
the Pesticide Root Zone/Exposure Analysis Modeling System (PRZM/EXAMS),
to produce estimates of pesticide concentrations in an index reservoir.
The SCI-GROW model is used to predict pesticide concentrations in
shallow ground water. For a screening-level assessment for surface
water EPA will use FIRST (a tier 1 model) before using PRZM/EXAMS (a
tier 2 model). The FIRST model is a subset of the PRZM/EXAMS model that
uses a specific high-end runoff scenario for pesticides.
While both FIRST and PRZM/EXAMS incorporate an index reservoir
environment, the PRZM/EXAMS model includes a percent crop area factor
as an adjustment to account for the maximum percent crop coverage
within a watershed or drainage basin.
    None of these models include consideration of the impact processing
(mixing, dilution, or treatment) of raw water for distribution as
drinking water would likely have on the removal of pesticides from the
source water. The primary use of these models by the Agency at this
stage is to provide a coarse screen for sorting out pesticides for
which it is highly unlikely that drinking water concentrations would
ever exceed human health levels of concern.
    Since the models used are considered to be screening tools in the
risk assessment process, the Agency does not use estimated
environmental concentrations (EECs) from these models to quantify
drinking water exposure and risk as a %RfD or %PAD. Instead drinking
water levels of comparison (DWLOCs) are calculated and used as a point
of comparison against the model estimates of a pesticide's
concentration in 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 from residential uses. Since
DWLOCs address total aggregate exposure to metsulfuron methyl they are
further discussed in the aggregate risk sections in Unit E.
    Based on the PRZM/EXAMS used to estimate the concentration of
metsulfuron methyl in surface water and FIRST to estimate the
concentration of metsulfuron methyl as a metabolite of iodosulfuron
methyl since FIRST has been used in estimating the drinking water
values for corn use with the proposed label for iodosulfuron methyl and
SCI-GROW models the EECs of metsulfuron methyl for acute exposures are
estimated to be 1.37 parts per billion (ppb) for surface water and
0.104 ppb for ground water. The EECs for chronic exposures are
estimated to be 0.332 ppb for surface water and 0.104 ppb for 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).
    Metsulfuron methyl is currently registered for use on the following
residential non-dietary sites: ornamental turf such as lawns, parks,
cemeteries, golf courses (fairways, aprons, tees, and roughs) and
similar non-crop areas, It has been determined that there is a
potential for exposure in residential settings during the application
process for homeowners who purchase and use products containing
metsulfuron methyl. There is also a potential for exposure from
entering areas previously treated with metsulfuron methyl such as turf
(i.e., lawns and parks) and golf courses that could lead to exposures
for adults and children. As a result, risk assessments have been
completed for both residential handler and postapplication scenarios.
Based on the use pattern, short-term exposure is expected. The risk
assessment was conducted using the following residential exposure
assumptions: The assumptions and factors used in the risk calculations
for handler exposure scenarios include:
     Exposure factors used to calculate daily exposures to
handlers are based on applicable data if available. For lack of
appropriate data, values from a scenario deemed similar enough by the
assessor might be used.
     The Agency always considers the maximum application rates
allowed by labels in its risk assessments to consider what is legally
possible based on the label. If additional information such as average
or typical rates are available, these values are also used to allow
risk managers to make a more informed risk management decision.
    The Agency bases calculations for residential risk assessments on
what would reasonably be treated by homeowners such as the size of the
lawn, or the size of a garden. This information was used by the Agency
to define chemical values for handlers which in turn are coupled with
unit exposure to calculate risks.
    Noncancer risk were calculated using the Margins of Exposure (MOE)
for two scenarios, (1) low pressure handwand and (2) hose-end sprayer.
Residential risk assessments apply an additional FQPA safety factor to
the risk when appropriate, which defines the level of concern. In the
case of metsulfuron methyl, no additional safety factor (1x) is
necessary to protect the safety of infants and children in assessing
metsulfuron methyl risks and exposure.
    Children may also be exposed by incidental non-dietary ingestion of
pesticide residues on residential lawns from hand to mouth transfer.
This scenario assumes that pesticide residues are transferred to the
skin of toddlers playing on recreational or residential lawns and turfs
and are subsequently ingested as a result of hand-to-mouth transfer.
The method for estimating postapplication incidental ingestion dose
from pesticide residues on turf is based on the following assumptions.
     On the day of application 5% of the application rate are
available on the turfgrass as dislodgeable residue. The 5% transfer
factor is based on data by Clothier (2000). (Science Advisory Council
for Exposure Policy #12: Recommended Revisions to the Standard
Operating Procedures (SOPs) for Residential Exposure Assessments;
Revised February 22, 2001).
     Postapplication activities are assessed on the same day
the pesticide is applied since it is assumed that toddlers could play
on the lawn immediately after application. For subsequent days after
application, an assumed 10% pesticide dissipation rate is used.
     The median surface area of both hands is 20 cm2
for a toddler. Since the hand-to-mouth has been defined by the February
1999 Science Advisory Panel (SAP) as 1 to 3 fingers (5.7 to 17.1
cm2) a screening level of 20 cm2 was selected
based on the assumption that each hand-to-mouth event equals 3 fingers
(Science Advisory Council for Exposure Policy #12: Recommended
Revisions to the Standard Operating Procedures (SOPs) for Residential
Exposure Assessments; Revised February 22, 2001).
     It is assumed that there is a one-to-one relationship
between the dislodgeable residues on the turf and on the surface area
of the skin after contact.
     The mean rate of hand-to-mouth activity is 20 events/hr
for toddlers age 2 to 5 years old for short-term exposure. The 1999 SAP
recommended the use of the 90th percentile value of 20
events based on reported hourly frequencies of hand-to-mouth events in
pre school children aged 2 to 5 years observations using video tapes by
Reed et al. (Science Advisory Council for Exposure Policy #12:
Recommended Revisions to the Standard Operating Procedures (SOPs) for
Residential Exposure Assessments; Revised February 22, 2001).
     The duration of exposure for toddlers is assumed to be 2
hours per day. This is based on the 75\th\ percentile value (i.e., 120
min/day) for playing on grass for ages 1 to 4 years and 5-11 years
(Tsang and Klepeis 1996 as cited on pag 15-79 of EPA 1997, Exposure
Factors Handbook EFH).
     Toddlers (age 3 years) used to represent the 1 to 6 year
old group, are assumed to weigh 15 kg. This is the mean of the median
values for male and female children (US EPA 1996a).
     A saliva extraction factor of 50% was used (Science
Advisory Council for Exposure Policy # 12: Recommended Revisions to the
Standard Operating Procedures (SOPs) for Residential Exposure Assessments; Revised
February 22, 2001).
    These values were used to calculate the MOE for incidental
ingestion of pesticide residues from hand to mouth transfer.
    Children (toddlers) may be exposed postapplication through
ingestion of pesticide treated turfgrass. This scenario assumes that
turf is ingested by toddlers who play on treated areas (i.e., yards,
playgrounds). The method for estimating postapplication ingestion
exposure to pesticide residues in turfgrass is based on the following
assumptions:
     On the day of application 5% of the application rate are
available to be ingested. This is assumed to represent an upper-
percentile input.
     Postapplication must be assessed on the same day the
pesticide is applied because it is assumed that toddlers could play on
the lawn immediately after application.
     The assumed ingestion rate for grass for toddlers (age 3
years) is 25 cm2/day. This value is intended to represent
the approximate area from which a child may grasp a handful of grass.
This is assumed to represent an upper-percentile input.
     Toddlers (age 3 years), used to represent the 1 to 6 year
old age group, are assumed to weigh 15 kg (U.S. EPA, 1996).
    These values were then used to calculate the MOE for ingestion of
pesticide treated turf. Children may be exposed postapplication through
ingestion of soil from pesticide treated residential areas. This
scenario assumes that pesticide residues in soil are ingested by
toddlers who play on treated areas as a result of normal mouthing
activities. The method for estimating postapplication ingestion
exposure to pesticide residues in soil is based on the following
assumptions:
     On the day of application, it is assumed that 100% of the
application rate are located within the soil's uppermost 1 cm.
     Postapplication must be assessed on the same day the
pesticide is applied because it is assumed that toddlers could play on
the lawn or other outdoor treated area immediately after application.
     The assumed soil ingestion rate for children (ages 1-6) is
100 mg/day. This is the mean soil ingestion rate value recommended by
EPA for use in exposure/risk assessments (U.S. EPA, 1996).
     Toddlers (age 3 years), used to represent the 1 to 6 year
old age group, are assumed to weigh 15 kg (U.S. EPA, 1996).
    These values were then used to calculate the MOE for soil ingestion
of pesticide treated areas.
    4. Cumulative exposure to substances with a 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."
    EPA does not have, at this time, available data to determine
whether metsulfuron methyl 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,
metsulfuron methyl 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 metsulfuron methyl 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 final rule for Bifenthrin Pesticide Tolerances (62
FR 62961, November 26, 1997).

D. Safety Factor for Infants and Children

    1. In general. 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 prenatal and postnatal
toxicity and the completeness of the data base on toxicity and exposure
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.
    2. Prenatal and postnatal sensitivity. There is no quantitative or
qualitative evidence of increased susceptibility in the pre-natal
studies in rat and rabbit or in the multi-generation reproduction study
evaluating pre- and post-natal exposure.
    3. Conclusion. There is a complete toxicity data base for
metsulfuron methyl and exposure data are complete or are estimated
based on data that reasonably accounts for potential exposures. EPA
determined that the 10X safety factor to protect infants and children
should be removed. The FQPA factor is removed because there is no
quantitative or qualitative evidence of increased susceptibility in the
pre-natal studies in rat and rabbit or in the multi-generation
reproduction study evaluating pre- and post-natal exposure; a
developmental neurotoxicity study is not required, and there are no
data deficiencies or residual uncertainties identified in the hazard
and exposure databases for metsulfuron methyl. The only study
outstanding for metsulfuron methyl is a 28-day inhalation (nose only)
study which is required due to the concern for the occupational
exposure via this route based on current use pattern.

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 the model estimates of
a pesticide's concentration in water (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 USEPA Office of Water are used to calculate
DWLOCs: 2L/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, EPA concludes with reasonable certainty that
exposures to the pesticide in drinking water (when considered along with other
sources of exposure for which EPA has reliable data) would not result
in unacceptable levels of aggregate human health risk at this time.
Because EPA 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, EPA 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. Because there was no acute endpoint attributable to
a single dose identified for metsulfuron methyl, EPA does not expect
metsulfuron methyl 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
metsulfuron methyl from food will utilize < 1% of the cPAD for the U.S.
population, < 1% of the cPAD for all infants and <1% of the cPAD for
children 1-6 years old. Based on the use pattern, chronic residential
exposure to residues of metsulfuron methyl is not expected. In
addition, there is potential for chronic dietary exposure to
metsulfuron methyl 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
the following Table 3:
Table 3.--Aggregate Risk Assessment for Chronic (Non-Cancer) Exposure to metsulfuron methyl
Population Subgroup
cPAD mg/
kg/day
% cPAD
(Food)
Surface
Water EEC
(ppb)
Ground
Water EEC
(ppb)
Chronic
DWLOC
(ppb)
U.S. Population
Children 1–6 years
Females 13–50 years
Males 13–19 years
0.25
0.25
0.25
0.25
<1
<1
<1
<1
0.332
0.332
0.332
0.332
0.104
0.104
0.104
0.104
8700
2500
7500
8700
    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).
    Metsulfuron methyl is currently registered for use that could
result in short-term residential exposure and the Agency has determined
that it is appropriate to aggregate chronic food and water and short-
term exposures for metsulfuron methyl.
    Using the exposure assumptions described in this unit for short-
term exposures, EPA has concluded that food and residential exposures
aggregated result in aggregate MOEs of 12,000 for children-short term
aggregate, and 39,000 for adults-short term aggregate. These aggregate
MOEs do not exceed the Agency's level of concern for aggregate exposure
to food and residential uses. In addition, short-term DWLOCs were
calculated and compared to the EECs for chronic exposure of metsulfuron
methyl in ground and surface water. After calculating DWLOCs and
comparing them to the EECs for surface and ground water, EPA does not
expect short-term aggregate exposure to exceed the Agency's level of
concern, as shown in the following Table 4:
Table 4.--Aggregate Risk Assessment for Short-Term Exposure to metsulfuron methyl
Population Subgroup
Aggregate
MOE (Food
+ Residential)
Aggregate Level of
Concern
(LOC)
Surface
Water EEC
(ppb)
Ground
Water EEC
(ppb)
Short-Term
DWLOC
(ppb)
Children
Adult
12,000
39,000
100
100
0.332
0.332
0.104
0.104
3,400
12,000
    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).
    Though residential exposure could occur with the use of metsulfuron
methyl, the potential intermediate-term exposures were not aggregated
with chronic dietary food and water exposures because the short- and
intermediate-term endpoints are the same (NOAEL = 34 mg/kg/day) and the
short-term aggregate risk assessment which includes the same routes of
exposure is worst-case and below the Agency level of concern.
Therefore, based on the best available data and current policies,
potential risks do not exceed the Agency's level of concern.
    5. Aggregate cancer risk for U.S. population. Since metsulfuron
methyl has been classified as "Not likely to be a human carcinogen",
metsulfuron methyl is not expected to pose a cancer risk.
    6. Determination of safety. Based on these risk assessments, EPA
concludes that there is a reasonable certainty that no harm will result
to the general population, and to infants and children from aggregate
exposure to metsulfuron methyl residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    Adequate methods are available for enforcement of tolerances for
residues of metsulfuron methyl in/on plant and animal commodities. PAM
Vol. II lists Methods I and III which are respectively capable of
determining residues of metsulfuron methyl per se (LOQ = 0.02 ppm for
wheat grain; 0.05 ppm for forage and straw) and combined Metabolites A
and A1 (LOQ = ppm for grain and forage; 0.1 ppm for straw); Method II
determines parent compound in ruminant tissues and milk to a lower
limit of 0.02-0.05 ppm.

B. International Residue Limits

    There are currently no Codex, Canadian, or Mexican maximum residue
levels (MRLs) for metsulfuron methyl, thus international harmonization
is not an issue.

C. Conditions

    A 28-day inhalation (nose-only) study is required as a condition of
registration.

V. Conclusion

    Therefore, tolerances are established for combined residues of
metsulfuron methyl, methyl 2-[[[[ (4-methoxy-6-methyl-1,3,5- triazin-2-
yl)amino]carbonyl] amino]sulfonyl]benzoate and its metabolite methyl 2-
[[[[( 4-methoxy-6-methyl-1,3,5-triazin-2-yl)
amino]carbonyl]amino]sulfonyl]- 4-hydroxybenzoate in or on sorghum,
grain, forage at 0.2 ppm; sorghum, grain, grain at 0.1 ppm; and
sorghum, grain, stover at 0.2 ppm. The text of paragraph (b) is removed
and reserved.

VI. Objections and Hearing Requests

    Under section 408(g) of the FFDCA, as amended by the 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
the FFDCA by the FQPA of 1996, EPA will continue to use those
procedures, with appropriate adjustments, until the necessary
modifications can be made. The new section 408(g) 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), as was provided in the old FFDCA sections 408 and 409.
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-2002-0160 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 October
7, 2002.
    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
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 (1900),
Environmental Protection Agency, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460. You may also deliver your request to the Office
of the Hearing Clerk in Rm. C400, Waterside Mall, 401 M St., SW.,
Washington, DC 20460. 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) 260-4865.
    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.
    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.
    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 Unit I.B.2. Mail your
copies, identified by docket ID number OPP-2002-0160, 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.
In person or by courier, bring a copy to the location of the PIRIB
described in Unit I.B.2. 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. Regulatory Assessment Requirements

    This final rule establishes a tolerance 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). 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 FFDCA section 408(d), such as the tolerance in this
final rule, do not require the issuance of a proposed rule, the
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et
seq.) do not apply. In addition, the Agency has determined that this
action will not have a substantial direct effect on States, on the
relationship between the national government and the States, or on the
distribution of power and responsibilities among the various levels of
government, as specified in Executive Order 13132, entitled
Federalism(64 FR 43255, August 10, 1999). Executive Order 13132
requires EPA to develop an accountable process to ensure "meaningful
and timely input by State and local officials in the development of
regulatory policies that have federalism implications." "Policies
that have federalism implications" is defined in the Executive Order
to include regulations that have "substantial direct effects on the
States, on the relationship between the national government and the
States, or on the distribution of power and responsibilities among the
various levels of government." This final rule directly regulates
growers, food processors, food handlers and food retailers, not States.
This action does not alter the relationships or distribution of power
and responsibilities established by Congress in the preemption
provisions of FFDCA section 408(n)(4). For these same reasons, the
Agency has determined that this rule does not have any "tribal
implications" as described in Executive Order 13175, entitled
Consultation and Coordination with Indian Tribal Governments (65 FR
67249, November 6, 2000). Executive Order 13175, requires EPA to
develop an accountable process to ensure "meaningful and timely input
by tribal officials in the development of regulatory policies that have
tribal implications." "Policies that have tribal implications" is
defined in the Executive Order to include regulations that have
"substantial direct effects on one or more Indian tribes, on the
relationship between the Federal Government and the Indian tribes, or
on the distribution of power and responsibilities between the Federal
Government and Indian tribes." This rule will not have substantial
direct effects on tribal governments, on the relationship between the
Federal Government and Indian tribes, or on the distribution of power
and responsibilities between the Federal Government and Indian tribes,
as specified in Executive Order 13175. Thus, Executive Order 13175 does
not apply to this rule.

VIII. Submission to Congress and the Comptroller General

    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: July 24, 2002
 Peter Caulkins,
Acting 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. 321(q), 346(a) and 371.

    2. Section 180.428 is amended as follows:
    i. By alphabetically adding entries for the commodities "sorghum,
grain, forage;" "sorghum, grain, grain", and "sorghum, grain,
stover" to the table in paragraph (a)(1) as set forth below.
    ii. The text of paragraph (b) is removed and reserved.

Sec. 180.428  Metsulfuron methyl; tolerances for residues.

    (a) General. (1)   *  *  *

------------------------------------------------------------------------
                      Commodity                        Parts per million
------------------------------------------------------------------------
                      *      *      *      *      *
Sorghum, grain, forage...............................                0.2
Sorghum, grain, grain................................                0.1
Sorghum, grain, stover...............................                0.2
                      *      *      *      *      *
------------------------------------------------------------------------

    (b) Section 18 emergency exemptions. [Reserved]
* * * * *
[FR Doc. 02-19807 Filed 8-6-02; 8:45 am]