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Halosulfuron-Methyl - Pesticide Tolerance 9/00

ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-301058; FRL-6746-2]
RIN 2070-AB78
Halosulfuron-methyl; Pesticide Tolerance
AGENCY:  Environmental Protection Agency (EPA).
ACTION:  Final rule.
-----------------------------------------------------------------------

SUMMARY:  This regulation establishes a tolerance for residues of
halosulfuron-methyl in or on the squash/cucumber subgroup. The
Interregional Research Project 4 (IR-4) requested this tolerance under
the Federal Food, Drug, and Cosmetic Act, as amended by the Food
Quality Protection Act of 1996.

DATES:  This regulation is effective September 29, 2000. Objections and
requests for hearings,identified by docket control number OPP-301058,
must be received by EPA on or before November 28, 2000.

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 control number OPP-301058 in the
subject line on the first page of your response.

FOR FURTHER INFORMATION CONTACT  By mail: Sidney Jackson, Registration
Division (7505C), Office of Pesticide Programs, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW.,Washington, DC 20460;
telephone number: (703) 305-7610; and e-mail address:
jackson.sidney@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

[[Page 58425]]

                                  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/. To access the OPPTS Harmonized
Guidelines referenced in the 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 control number OPP-301058. 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 August 23, 2000 (65 FR 51314) (FRL-6738-
9), EPA issued a notice pursuant to section 408 of the Federal Food,
Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a as amended by the Food
Quality Protection Act of 1996 (FQPA) (Public Law 104-170) announcing
the filing of a pesticide petition (0E6085) for tolerance by IR-4, 681
U.S. Highway 1 South, North Brunswick, New Jersey 08902-3390. This
notice included a summary of the petition prepared by Monsanto Company,
the registrant. There were no comments received in response to the
notice of filing.
    The petition requested that 40 CFR 180.479 be amended by
establishing a tolerance for residues of the herbicide halosulfuron-
methyl, methyl 5-(4,6-dimethoxy-2-pyrimidinyl)amino
carbonylaminosulfonyl-3-chloro-1-methyl-1H-pyrazole-4-carboxylate, and
its metabolites determined as 3-chloro-1-methyl-5-sulfamoylpyrazole-4-
carboxylic acid, in or on the squash/cucumber subgroup at 0.5 parts per
million (ppm).
    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 November 26, 1997 (62 FR 62961) (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 a tolerance for residues of halosulfuron-methyl on
squash/cucumber subgroup at 0.5 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 halosulfuron-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. Acute toxicological
studies placed the technical-grade halosulfuron-methyl in Toxicity
Category III for acute dermal toxicity and in Category IV for all other
types of acute toxicity.

            Table 1.--Subchronic, Chronic, and Other Toxicity
------------------------------------------------------------------------
          Guideline No.               Study type            Results
------------------------------------------------------------------------
870.3100                          90-day oral         NOAEL = 116 males/
                                   toxicity rodents    147 females
                                                       milligrams/
                                                       kilograms/day (mg/
                                                       kg/day)

[[Page 58426]]

                                                      LOAEL = 497 males/
                                                       640 females mg/kg/
                                                       day based on
                                                       decreased body
                                                       weight gain,
                                                       decreased
                                                       absolute weights
                                                       of adrenal,
                                                       liver, thymus,
                                                       heart, and
                                                       kidneys,
                                                       decreased
                                                       cholesterol,
                                                       bilirubin, total
                                                       protein, albumin,
                                                       and calcium;
                                                       increases in MCH,
                                                       ALT, and
                                                       creatinine; and
                                                       vacuolated livers
                                                       and pigmented
                                                       kidney tubules.
------------------------------------------------------------------------
870.3200                          21/28-day dermal    NOAEL = 100
                                   toxicity (rats)     (males), 1,000
                                                       (females) mg/kg/
                                                       day
                                                      LOAEL = 1,000/
                                                       >1,000 mg/kg/day
                                                       male/female (M/F)
                                                       based on dose-
                                                       related decrease
                                                       in total body
                                                       weight gain in
                                                       males.
------------------------------------------------------------------------

870.3700a                         Prenatal            Maternal NOAEL =
                                   developmental in    250 mg/kg/day
                                   rodents (rat)
                                                      Maternal LOAEL =
                                                       750 mg/kg/day
                                                       (increased
                                                       incidence of
                                                       clinical
                                                       observations; and
                                                       reduced body
                                                       weight gains,
                                                       food consumption,
                                                       and food
                                                       efficiency)
                                                      Developmental

                                                       NOAEL= 250 mg/kg/
                                                       day
                                                      Developmental
                                                       LOAEL = 750 mg/kg/
                                                       day (decreased
                                                       mean litter size,
                                                       increased number
                                                       of resorptions,
                                                       decreased mean
                                                       fetal body
                                                       weight, increases
                                                       in fetal and
                                                       litter incidences
                                                       of dilation of
                                                       the lateral
                                                       ventricles and
                                                       other anomalies
                                                       in the
                                                       development of
                                                       the fetal nervous
                                                       system, and
                                                       skeletal
                                                       variations such
                                                       as anomalies or
                                                       delays in
                                                       ossification in
                                                       the thoracic
                                                       vertebrae,
                                                       sternebrae, and
                                                       ribs)
------------------------------------------------------------------------
870.3700b                         Prenatal            Maternal NOAEL =
                                   developmental in    50 mg/kg/day
                                   nonrodents
                                   (rabbit)
                                                      Maternal LOAEL =
                                                       150 mg/kg/day
                                                       (decreased body
                                                       weight gain, food
                                                       consumption, and
                                                       food efficiency)
                                                      Developmental
                                                       NOAEL= 50 mg/kg/
                                                       day
                                                      Developmental
                                                       LOAEL = 150 mg/kg/
                                                       day (decreased
                                                       mean litter size,
                                                       increased number
                                                       of resorptions
                                                       and increased
                                                       post implantation
                                                       loss)
------------------------------------------------------------------------
870.3800                          Reproduction and    Parental/Systemic
                                   fertility effects   NOAEL = 50.5 /
                                                       58.7 mg/kg/day M/
                                                       F
                                                      Parental/Systemic
                                                       LOAEL = 223.2 /
                                                       261.4 mg/kg/day M/
                                                       F - reductions in
                                                       body weight, body
                                                       weight gains, and
                                                       food consumption
                                                       during the
                                                       premating period
                                                       in both sexes)
                                                      Offspring NOAEL >
                                                       261.4 mg/kg/day
                                                       highest dose
                                                       tested (HDT).
------------------------------------------------------------------------
870.4100b                         Chronic toxicity    NOAEL (systemic) =
                                   dogs                10 mg/kg/day
                                                      LOAEL (systemic) =
                                                       40 mg/kg/day
                                                       (decreased body
                                                       weight gains and
                                                       changes in
                                                       hematological and
                                                       blood chemistry
                                                       parameters in
                                                       females)
------------------------------------------------------------------------
870.4200                          Carcinogenicity     NOAEL (systemic) =
                                   mice                410 / 1214.6 mg/
                                                       kg/day M/F
                                                      LOAEL (systemic) =
                                                       971.9 / 1214.6 mg/
                                                       kg/day M/F -
                                                       decreased mean
                                                       body weight in
                                                       males, increased
                                                       incidence of
                                                       microconcentratio
                                                       n/mineralization
                                                       in the testis and
                                                       epididymides) No
                                                       evidence of
                                                       carcinogenicity
------------------------------------------------------------------------
870.4300                          Combined toxicity/  NOAEL (systemic) =
                                   carcinogenicity     108.3 / 56.4 mg/
                                   rats                kg/day M/F
                                                      LOAEL (systemic) =
                                                       225.2 / 138.6 mg/
                                                       kg/day M/F -
                                                       marginal
                                                       decreases in body
                                                       weight gains) No
                                                       evidence of
                                                       carcinogenicity

[[Page 58427]]

870.7485                          Metabolism and      Radiolabelled
                                   pharmacokinetics    technical was
                                                       administered to 5
                                                       rats/sex/group as
                                                       a single low-dose
                                                       (5 mg/kg), single
                                                       high-dose (250 mg/
                                                       kg), or repeated
                                                       low-dose (5 mg/kg/
                                                       day x 14 days).
                                                       Absorption was
                                                       rapid, incomplete
                                                       sic, and similar
                                                       in both sexes.
                                                       Elimination was
                                                       via urine and
                                                       feces within 72
                                                       hours, and
                                                       appeared to be
                                                       independent of
                                                       dose and sex.
                                                       Desmethyl
                                                       halosulfuron-
                                                       methyl and its 5-
                                                       hydroxy
                                                       derivative were
                                                       the major urinary
                                                       and fecal
                                                       metabolites.
------------------------------------------------------------------------
                                  Genotoxicity        Bacterial/
                                                       mammalian
                                                       microsomal
                                                       mutagenicity
                                                       assays were
                                                       performed and
                                                       halosulfuron-
                                                       methyl was found
                                                       not to be
                                                       mutagenic. Two
                                                       mutagenicity
                                                       studies were
                                                       performed to test
                                                       gene mutation and
                                                       found to produce
                                                       no chromosomal
                                                       aberrations or
                                                       gene mutations in
                                                       cultured Chinese
                                                       hamster ovary
                                                       cells. An in vivo
                                                       mouse
                                                       micronucleus
                                                       assay did not
                                                       cause a
                                                       significant
                                                       increase in the
                                                       frequency of
                                                       micronucleated
                                                       polychromatic
                                                       erythrocytes in
                                                       bone marrow
                                                       cells. A
                                                       mutagenicity
                                                       study was
                                                       performed on rats
                                                       and found not to
                                                       induce
                                                       unscheduled DNA
                                                       synthesis in
                                                       primary rat
                                                       hepatocytes.

------------------------------------------------------------------------
                                  Endocrine           No specific tests
                                   disruption          have been
                                                       conducted with
                                                       halosulfuron-
                                                       methyl to
                                                       determine whether
                                                       the chemical may
                                                       have an effect in
                                                       humans that is
                                                       similar to an
                                                       effect produced
                                                       by a naturally
                                                       occurring
                                                       estrogen or other
                                                       endocrine
                                                       effects. However,
                                                       there were no
                                                       significant
                                                       findings in other
                                                       relevant toxicity
                                                       tests, i.e.,
                                                       teratology and
                                                       multi- generation
                                                       reproduction
                                                       studies, which
                                                       would suggest
                                                       that halosulfuron-
                                                       methyl produces
                                                       effects
                                                       characteristic of
                                                       the disruption of
                                                       the estrogenic
                                                       hormone.
------------------------------------------------------------------------

B. Toxicological Endpoints

    The dose at which verved (the NOAEL) from the toxicology study
identified as appropriate for use in risk assessment is used to
estimate the toxicological level of concern (LOC). However, the lowest
dose at which adverse effects of concern are identified (the LOAEL) is
sometimes used for risk assessment if no NOAEL was achieved in the
toxicology study selected. An uncertainty factor (UF) is applied to
reflect uncertainties inherent in the extrapolation from laboratory
animal data to humans and in the variations in sensitivity among
members of the human population as well as other unknowns. An UF of 100
is routinely used, 10X to account for interspecies differences and 10X
for 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 (MOEcancer = point of
departure/exposures) is calculated. A summary of the toxicological
endpoints for halosulfuron-methyl used for human risk assessment is
shown in the following Table 2:

[[Page 58428]]

 Table 2.--Summary of Toxicological Doses and Endpoints for halosulfuron-methyl for Use in Human Risk Assessment
----------------------------------------------------------------------------------------------------------------
                                                                 FQPA SF* and level of
          Exposure scenario               Dose used in risk         concern for risk     Study and toxicological
                                            assessment, UF             assessment                effects
----------------------------------------------------------------------------------------------------------------
Acute dietary females 13-50 years of   NOAEL = 50 mg/kg/day,    FQPA SF = 1X, aPAD =     Developmental rabbit
 age, infants and children.             UF = 100 acute RfD =     acute RfD FQPA SF =      LOAEL = 150 mg/kg/day
                                        0.5 mg/kg/day            0.5 mg/kg/day            based on decreased
                                                                                          mean litter size and
                                                                                          increases in
                                                                                          resorptions and post-
                                                                                          implantation loss.
----------------------------------------------------------------------------------------------------------------
Chronic dietary all populations        NOAEL = 10 mg/kg/day UF  FQPA SF = 1X, cPAD =     Chronic toxicity - dog
                                        = 100, Chronic RfD =     chronic RfD FQPA SF =    LOAEL = 40 mg/kg/day
                                        0.1 mg/kg/day            0.1 mg/kg/day            based on decrease in
                                                                                          bodyweight gain and
                                                                                          alterations in
                                                                                          hematology and
                                                                                          clinical chemistry
                                                                                          parameters.
----------------------------------------------------------------------------------------------------------------
Short-term dermal (1 to 7 days)        oral NOAEL = 50 mg/kg/   LOC for MOE = 100        Developmental - rabbit
 (Residential)                          day, (dermal             (Residential)            LOAEL = 150 mg/kg/day
                                        absorption rate = 75%)                            based on decreased
                                                                                          mean litter size and
                                                                                          increases in
                                                                                          resorptions, and post-
                                                                                          implantation loss.
----------------------------------------------------------------------------------------------------------------
Interme diate-term dermal (1 week to   oral NOAEL = 10 mg/kg/   LOC for MOE = 100        Chronic toxicity dog
 several months) (Residential)          day, (dermal             Residential              LOAEL = 40 mg/kg/day
                                        absorption rate = 75%                             based on decrease in
                                                                                          bodyweight gain and
                                                                                          alterations in
                                                                                          hematology and
                                                                                          clinical chemistry
                                                                                          parameters.
----------------------------------------------------------------------------------------------------------------
Long-term dermal (several months to    oral NOAEL= 10 mg/kg/    LOC for MOE = 100        Chronic toxicity - dog
 lifetime) (Residential)                day (dermal absorption   (Residential)            LOAEL = 40 mg/kg/day
                                        rate = 75%                                        based on decreased
                                                                                          body weight gain and
                                                                                          alterations in
                                                                                          hematology and
                                                                                          clinical chemistry
                                                                                          parameters.
----------------------------------------------------------------------------------------------------------------
*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 180.479) for the residues of halosulfuron-methyl,
in or on various raw agricultural commodities (RACs) with tolerances
ranging from 0.05 to 0.8 ppm. Halosulfuron-methyl is currently
registered on a variety of use sites, including agricultural crops and
residential lawns. Tolerances have been established for plant and
animal RACs including field corn at 0.05 ppm, grain sorghum (milo) at
0.05 ppm, sweet corn (kernel + cobs with husks removed) at 0.05 ppm,
pop corn grain at 0.05 ppm, sugarcane cane at 0.05 ppm, tree nuts
nutmeat at 0.05 ppm, pistachio nuts nutmeat at 0.05 ppm, cotton
undelinted seed at 0.05 ppm, and rice grain at 0.05 ppm; and secondary
tolerances in meat and meat by-products at 0.1 ppm (cattle, goats,
hogs, horses, and sheep). Tolerances are established for indirect or
inadvertent residues of halosulfuron-methyl ranging from 0.1 to 0.5 ppm
in or on certain soybean and wheat RACs when present therein as a
result of the application of halosulfuron-methyl to growing crops.
Indirect or inadvertent tolerances including soybean forage at 0.5 ppm,
soybean hay at 0.5 ppm, soybean seed at 0.5 ppm, wheat forage at 0.1,
wheat grain at 0.1, and wheat straw at 0.2 have also been established
for RACs. Tolerances for the fruiting vegetable crop group 8 have been
proposed by Gowan Company at 0.05 ppm. An additional tolerance is
herein being requested for the crop group 9B, squash/cucumber subgroup
of the cucurbit vegetable group, at 0.5 ppm. Risk assessments were
conducted by EPA to assess dietary exposures from halosulfuron-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. The acute dietary endpoint for halosulfuron-methyl
was based on developmental effects (decreased mean litter size,
increased resorptions, and increased postimplantation loss). The
endpoint applies only to subgroups consisting of females (aged 13-50
years), infants and children. The 10X FQPA factor was removed,
therefore, the acute RfD of 0.5 mg/kg/day is equal to the aPAD. 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 acute exposure assessments:
acute dietary exposure analysis was performed assuming tolerance level
residues and 100% crop treated for all commodities for which
halosulfuron-methyl is registered as well as for crops in the cucumber/
squash subgroup (9B), which are being evaluated in this action.
Further, standard processing factors were used for all processed
commodities. The results of the DEEM analysis indicate that exposure
for all applicable subgroups is less than 1% of the aPAD at the
95th percentile.
    ii. Chronic exposure. In conducting this chronic dietary risk
assessment the 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

[[Page 58429]]

the chemical for each commodity. The following assumptions were made
for the chronic exposure assessments: chronic dietary analysis was
performed assuming tolerance level residues and 100% crop treated for
all commodities for which halosulfuron-methyl is registered as well as
for crops in the cucumber/squash subgroup (9B), which are being
evaluated in this action. The results of the DEEM analysis indicate
that exposure for all applicable subgroups is less than 1% of the cPAD.
    The chronic dietary endpoint for halosulfuron-methyl is based on
decreased body weight gains, changes in hematological and blood
chemistry parameters. Since the 10X FQPA factor was removed, the
chronic RfD of 0.1 mg/kg/day is equal to the cPAD.
    iii. Cancer. Halosulfuron-methyl is classified as a "not likely"
human carcinogen based on a lack of evidence of carcinogenicity in male
and female mice and rats. A cancer risk assessment is not required.
    2. Dietary exposure from drinking water. The Agency lacks
sufficient monitoring exposure data to complete a comprehensive dietary
exposure analysis and risk assessment for halosulfuron-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 halosulfuron-methyl.
    The Agency uses the Generic Estimated Environmental Concentration
(GENEEC) or the Pesticide Root Zone/Exposure Analysis Modeling System
(PRZM/EXAMS) to estimate pesticide concentrations in surface water and
SCI-GROW, which predicts pesticide concentrations in ground water. In
general, EPA will use GENEEC (a tier 1 model) before using PRZM/EXAMS
(a tier 2 model) for a screening-level assessment for surface water.
The GENEEC model is a subset of the PRZM/EXAMS model that uses a
specific high-end runoff scenario for pesticides. GENEEC incorporates a
farm pond scenario, while PRZM/EXAMS incorporate an index reservoir
environment in place of the previous pond scenario. 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 halosulfuron-methyl they are
further discussed in the aggregate risk sections below.
    Based on the PRZM/EXAMS and SCI-GROW models the estimated
environmental concentrations (EECs) of halosulfuron-methyl in surface
water and ground water for acute exposures are estimated to be 4.73
parts per billion (ppb) for surface water and 0.097 ppb for ground
water. The EECs for chronic exposures are estimated to be 1.4 ppb for
surface water and 0.097 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).
    Halosulfuron-methyl is currently registered for use on the
following residential non-dietary site: residential lawns. The risk
assessment was conducted using the following residential exposure
assumptions: Adults may be dermally exposed after treatments to lawns,
and children may be exposed through dermal, hand-to-mouth and
incidental oral sources.
    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 halosulfuron-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,
halosulfuron-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 halosulfuron-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
November 26, 1997 (62 FR 62961).

D. Safety Factor for Infants and Children

    1. Safety factor for infants and children-- 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 margin of exposure (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. The available data provided
no indication of increased susceptibility of rats or rabbits to in
utero and/or postnatal exposure to halosulfuron-methyl.
    3. Conclusion. A postnatal developmental neurotoxicity study in
rats is required for confirmatory purposes because of evidence of fetal
nervous system alterations in rats at 750 mg/kg/day. This requirement
is a condition of registration.
    Notwithstanding the above study requirement, there is an otherwise
complete toxicity data base for halosulfuron-methyl and exposure data
are complete or are estimated based on data that reasonably accounts
for potential exposures. EPA determined that the 10X FQPA Safety Factor
to protect infants and children should be removed because:
    i. There was no indication of increased susceptibility of rats or
rabbits to in utero and/or postnatal exposure to halosulfuron-methyl.
In the prenatal developmental toxicity studies in rats

[[Page 58430]]

and rabbits and the two-generation reproduction study in rats, effects
in the offspring were observed only at or above treatment levels which
resulted in evidence of parental toxicity.
    ii. The committee determined that the requirement of a
developmental neurotoxicity study in rats did not warrant an
application of additional safety factors because:
    a. The alterations observed in the fetal nervous system occurred in
only one species (in rats and not in rabbits)
    b. The fetal effects which will be investigated in the required
developmental neurotoxicity study were seen only at a dose of 750 mg/
kg/day which is close to the limit-dose (LTD) (1,000 mg/kg/day).
    c. There was no evidence of clinical signs of neurotoxicity, brain
weight changes, or neuropathology in the subchronic or chronic studies
in rats.
    d. The developmental neurotoxicity study is required only as
confirmatory data to understand what the effect is at a high exposure
(dose) level.
    e. Exposure assessments do not indicate a concern for potential
risk to infants and children based on the results of the field trial
studies and the very low application rate ( 0.06 lbs. active ingredient
(a.i) per acre). Detectable residues are not expected in foods.

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. Using the exposure assumptions discussed in this
unit for acute exposure, the acute dietary exposure from food to
halosulfuron-methyl will occupy < 1.0 percent of the aPAD for the U.S.
population, < 1.0 percent of the aPAD for females 13 years and older, <
1.0 percent of the aPAD for infant subpopulation and < 1.0 percent of
the aPAD for children population. In addition, there is potential for
acute dietary exposure to halosulfuron-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 aPAD, as shown in following Table 3:

Table 3.--Aggregate Risk Assessment for Acute Exposure to halosulfuron-methyl
--------------------------------------------------------------------------------------------------------
                                                                  Surface       Ground
             Population Subgroup       aPAD (mg/      %aPAD      water EEC    water EEC     Acute DWLOC
                                          kg)         (Food)       (ppb)        (ppb)          (ppb)
--------------------------------------------------------------------------------------------------------
(All Infants)                                0.50         <1.0         4.73        0.097           5,000
 Female (13-50 years)                        0.50         <1.0         4.73        0.097          15,000
Children (1-6 years)                         0.50         <1.0         4.73        0.097           5,000
--------------------------------------------------------------------------------------------------------

    2. Chronic risk. Using the exposure assumptions described in this
unit for chronic exposure, EPA has concluded that exposure to
halosulfuron-methyl from food will utilize <1.0% of the cPAD for the
U.S. population, for infant subpopulations at greatest exposure and for
children subpopulation at greatest exposure]. Based the use pattern,
chronic residential exposure to halosulfuron-methyl is not expected. In
addition, there is potential for chronic dietary exposure to
halosulfuron-methyl in drinking water. After calculating the 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 4:

Table 4.--Aggregate Risk Assessment for Chronic (Non-Cancer) Exposure to halosulfuron-methyl
--------------------------------------------------------------------------------------------------------
                                                                  Surface       Ground
             Population subgroup      cPAD mg/kg/     %cPAD      water EEC    water EEC    Chronic DWLOC
                                          day         (Food)       (ppb)        (ppb)          (ppb)
--------------------------------------------------------------------------------------------------------
U.S. population                              0.10         <1.0          1.4        0.097           3,500

[[Page 58431]]

(All Infants                                 0.10         <1.0          1.4        0.097             990
Children (1-6 years)                         0.10         <1.0          1.4        0.097           1,000
Females (13-50 years)                        0.10         <1.0          1.4        0.097           2,300
Males (13-19 years)                          0.10         <1.0          1.4        0.097           3,500
--------------------------------------------------------------------------------------------------------

    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). Halosulfuron-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 halosulfuron-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 310 and 2,200 for all infants
and females (13 to 50 years), respectively. Note that there is no oral
residential exposure for adults. 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 halosulfuron-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 5:

Table 5.--Aggregate Risk Assessment for Short-Term Exposure to halosulfuron-methyl
------------------------------------------------------------------------------------------------------------------------
                        Aggregate MOE (Food +   Aggregate level of   Surface water EEC   Ground water EEC   Short-term
  Population subgroup       Residential)           concern (LOC)           (ppb)              (ppb)         DWLOC (ppb)
------------------------------------------------------------------------------------------------------------------------

(All Infants)                    310                   100                  1.4               0.097              4,900
Females (13-50 years)          2,200                   100                  1.4               0.097             10,000
------------------------------------------------------------------------------------------------------------------------

    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). Halosulfuron-
methyl is currently registered for use(s) that could result in
intermediate-term residential exposure and the Agency has determined
that it is appropriate to aggregate chronic food and water and
intermediate-term exposures for halosulfuron-methyl.
    Using the exposure assumptions described in this unit for
intermediate-term exposures, EPA has concluded that food and
residential exposures aggregated result in aggregate MOEs of 1,000,
1,700, and 2,000 for all infants, females (13 to 50 years) and males
(13 to 19), respectively. It should be noted that there is no oral
residential exposure for adults. These aggregate MOEs do not exceed the
Agency's level of concern for aggregate exposure to food and
residential uses. In addition, intermediate-term DWLOCs were calculated
and compared to the EECs for chronic exposure of halosulfuron-methyl in
ground and surface water. After calculating DWLOCs and comparing them
to the EECs for surface and ground water, EPA does not expect
intermediate-term aggregate exposure to exceed the Agency's level of
concern, as shown in the following Table 6:

Table 6.--Aggregate Risk Assessment for Intermediate-Term Exposure to halosulfuron-methyl
-----------------------------------------------------------------------------------------------------------------------
                      Aggregate MOE (Food +  Aggregate level of  Surface water EEC  Ground water EEC  Intermediate-term
Population subgroup    Residential)(oral)      concern (LOC)           (ppb)              (ppb)          DWLOC (ppb)
-----------------------------------------------------------------------------------------------------------------------
(All Infants)               1,000                  100                 1.4                0.097              920
Females (13-50 years        1,700                  100                 1.4                0.097            2,800
Males (13-19 years)         2,000                  100                 1.4                0.097            3,300
-----------------------------------------------------------------------------------------------------------------------

    5. Aggregate cancer risk for U.S. population. Halosulfuron-methyl
is classified as a "not likely" human carcinogen based on a lack of
evidence of carcinogenicity in male and female mice and rats.

[[Page 58432]]

    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 halosulfuron-methyl residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    The analytical method for cucumber and squash is based on
"Analytical Method for the Determination of MON 12000 and 3-
Chlorosulfonamide Acid Producing residues in Field Corn", Monsanto
Doc. No. RES-026-92. This method has been submitted to FDA for
publication in the Pesticide Analytical Manual (PAM) II. The analytical
method involves sample extraction, acid hydrolysis under reflux to
convert halosulfuron-methyl to 3-chlorosulfonamide acid (CSA), and
derivatization to convert the CSA to chlorosufonamide ester (CSE).
Detection is by GC/ECD (gas chromatography using electron capture
detection). Quantitation is expressed in terms of halosulfuron-methyl
equivalents. Chromatograms, calibration curves and calculations were
included in this submission. The Agency concludes that the GC/ECD
method is adequate for enforcement of tolerances and data collection on
residues of halosulfuron-methyl in or on squash/cucumber subgroup.
Information regarding availability of the method may be requested from:
Calvin Furlow, PIRIB, IRSD (7502C), Office of Pesticide Programs,
Environmental Protection Agency, 1200 Pennsylvania Ave., NW,
Washington, DC 20460; telephone number: (703) 305-5229; e-mail address:
furlow.calvin@epa.gov.

B. International Residue Limits

    There are no Codex, Canadian, or Mexican maximum residue limits
(MRL) for halosulfuron-methyl in or on squash/cucumber subgroup.
Therefore, international harmonization is not an issue for this
tolerance.

C. Conditions

    The Agency requires a satisfactory postnatal developmental
neurotoxicity study in rats for confirmatory purposes because of
evidence of fetal nervous system alterations in rats at 750 mg/kg/day.
The study requirement is a condition of this registration.

V. Conclusion

    Therefore, the tolerance is established for residues of
halosulfuron-methyl, methyl 5-(4,6-dimethoxy-2-pyrimidinyl)amino
carbonylaminosulfonyl-3-chloro-1-methyl-1H-pyrazole-4-carboxylate, and
its metabolites determined as 3-chloro-1-methyl-5-sulfamoylpyrazole-4-
carboxylic acid, in or on the squash/cucumber subgroup at 0.5 ppm.

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 control number OPP-301058 in the subject line on the
first page of your submission. All requests must be in writing, and
must be mailed or delivered to the Hearing Clerk on or before November
28, 2000.
    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 control number OPP-301058, 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.

[[Page 58433]]

Copies of electronic objections and hearing requests will also be
accepted on disks in WordPerfect 6.1/8.0 file format 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 October 4, 1993 (58 FR 51735). 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 prior consultation as specified by Executive Order
13084, entitled Consultation and Coordination with Indian Tribal
Governments May 19, 1998 (63 FR 27655); special considerations as
required by Executive Order 12898, entitled Federal Actions to Address
Environmental Justice in Minority Populations and Low-Income
Populations February 16, 1994 (59 FR 7629); or require OMB review or
any Agency action under Executive Order 13045, entitled Protection of
Children from Environmental Health Risks and Safety Risks April 23,
1997 (62 FR 19885). 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 August 10, 1999 (64 FR
43255). 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).

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: September 21, 2000.

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. 321(q), (346a) and 371.

    2. Section 180.479 is amended by alphabetically adding an entry to
the table in paragraph (a)(2) for "squash/cucumber subgroup" to read
as follows:

Sec. 180.479  Halosulfuron-methyl, tolerances for residues.

* * * * *
    (a)* * *

-------------------------------------------------
Commodity                       Parts per million
-------------------------------------------------
                                   *  *  *  *  *
 Squash/cucumber subgroup                  0.5
                                   *  *  *  *  *
-------------------------------------------------

[[Page 58434]]

* * * * *
[FR Doc. 00-25048 Filed 9-28-00; 8:45 am]
BILLING CODE 6560--50--S