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imazapic (Cadre) Pesticide Tolerance 12/01

  


ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-301198; FRL-6816-2]
RIN 2070-AB78

Imazapic; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This regulation establishes a tolerance for combined residues
of imazapic, ()-2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-
5-oxo-1H-imidazol-2-yl]-5-methyl-3-pyridinecarboxylic acid and its
metabolite ()-2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-
oxo-1H-imidazol-2-yl]-5-hydroxymethyl-3-pyridinecarboxylic acid, both
free CL 263284 and conjugated CL 189215) in or on grass, forage and
grass, hay and the combined residues of imazapic and its metabolite CL
263284 in or on milk; fat, meat, and meat byproducts (except kidney) of
cattle, goats, horses, and sheep; and kidney of cattle, goats, horses,
and sheep. BASF 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 December 26, 2001. Objections and
requests for hearings, identified by docket control number OPP-301198,
must be received by EPA on or before February 25, 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 control number OPP-301198 in the
subject line on the first page of your response.

FOR FURTHER INFORMATION CONTACT: By mail: James A. Tompkins, Product
Manager (PM) 25, Registration Division (7505C), Office of Pesticide
Programs, Environmental Protection Agency, 1200 Pennsylvania Ave.,
NW.,Washington, DC 20460; telephone number: (703) 305-5697; and 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 control number OPP-301198. 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 24, 2000 (65 FR 51608) (FRL-6598-
6), 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 (PP 9F5092) for tolerance by
American Cyanamid Company, P.O. Box 400, Princeton, NJ 08543-0400. This
notice included a summary of the petition prepared by American
Cyanamid, the registrant at the time of filing. The current registrant
for the chemical is BASF, at the same address. There were no comments
received in response to the notice of filing.
     The petition requested that 40 CFR 180.490(a) be amended by
establishing a tolerance for combined residues of the herbicide
imazapic and its hydroxymethyl metabolite, both free (CL 263284) and
conjugated (CL 189215) in or on the raw agricultural commodities grass,
forage at 35 ppm, and grass, hay at 15 parts per million (ppm).
Tolerances were also proposed for the combined residues of imazapic and
its free hydroxymethyl metabolite in or on milk at 0.1 ppm; fat, meat,
and meat byproducts (except kidney) of cattle, goats, horses, and sheep
at 0.1 ppm; and kidney of cattle, goats, horses, and sheep at 2.0 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 (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 a tolerance for combined residues of imazapic and its
metabolite, both free CL 263284 and conjugated CL 189215, in or on
grass, forage at 30 ppm, and grass, hay at 15 ppm; and for the combined
residues of imazapic and its free hydroxymethyl metabolite in milk at
0.1 ppm; fat, meat, and meat byproducts (except kidney) of cattle,
goats, horses, and sheep at 0.1 ppm; and kidney of cattle, goats,
horses, and sheep at 1.0 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 imazapic 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.--Imazapic Technical Subchronic, Chronic, and Other Toxicity
------------------------------------------------------------------------
                                     Study Type (All
           Guideline No.                 Studies             Results
                                       Acceptable)
------------------------------------------------------------------------
870.3100                          90-Day oral         NOAEL = 1,552 mg/
                                    toxicity rodents-   kg/day in males,
                                    rat                 1,728 mg/kg/day
                                                        in females (HDT)
                                                       LOAEL = not
                                                        established
------------------------------------------------------------------------
870.3200                          21-Day dermal       NOAEL = 1,000 mg/
                                    toxicity-rabbit     kg/day (males and
                                                        females)
                                                       LOAEL = not
                                                        established
------------------------------------------------------------------------
870.3700                          Prenatal            Maternal NOAEL =
                                    developmental in    1,000 mg/kg/day
                                    rodents-rat         (HDT)
                                                       LOAEL = not
                                                        established
                                                       Developmental
                                                        NOAEL = 1,000 mg/
                                                        kg/day
                                                       LOAEL = not
                                                        established
------------------------------------------------------------------------
870.3700                          Prenatal            Maternal NOAEL =
                                    developmental in    350 mg/kg/day
                                    nonrodents-rabbit  LOAEL = 500 mg/kg/
                                                        day based on
                                                        decreased body
                                                        weight gain and
                                                        food consumption.
                                                        At 700 mg/kg/day
                                                        (HDT), there was
                                                        excessive
                                                        mortality
                                                        resulting in a
                                                        total of only 7
                                                        surviving litters
                                                       Developmental
                                                        NOAEL = 500 mg/kg/
                                                        day
                                                       LOAEL = not
                                                        established. Due
                                                        to excessive
                                                        mortality at 700
                                                        mg/kg/day, only
                                                        47 fetuses were
                                                        available for
                                                        examination which
                                                        precluded a
                                                        meaningful
                                                        evaluation of
                                                        developmental
                                                        findings at this
                                                        dose level
------------------------------------------------------------------------
870.3800                          Reproduction and    Parental/Systemic
                                    fertility effects-  NOAEL = 1,205 mg/
                                    rat                 kg/day in males,
                                                        1,484 mg/kg/day
                                                        in females (HDT)
                                                       LOAEL = not
                                                        established
                                                       Reproductive NOAEL
                                                        = 1,205 mg/kg/day
                                                        in males, 1,484
                                                        mg/kg/day in
                                                        females
                                                       LOAEL = not
                                                        established
                                                       Offspring NOAEL =
                                                        1,205 mg/kg/day
                                                        in males, 1,484
                                                        mg/kg/day in
                                                        females
                                                       LOAEL = not
                                                        established
------------------------------------------------------------------------
870.4100                          Chronic toxicity    NOAEL = not
                                    dogs                established
                                                       LOAEL = 137 mg/kg/
                                                        day in males, 180
                                                        mg/kg/day in
                                                        females based on
                                                        increased
                                                        incidence of
                                                        minimal
                                                        degeneration and/
                                                        or necrosis and
                                                        lymphocyte and/or
                                                        macrophage
                                                        infiltration in
                                                        skeletal muscle
                                                        in both males and
                                                        females and
                                                        slightly
                                                        decreased blood
                                                        creatinine levels
                                                        in females (LDT)
------------------------------------------------------------------------
870.4100/870.4200                 Chronic/            NOAEL = 1,029 mg/
                                    carcinogenicity     kg/day in males,
                                    rats                1,237 mg/kg/day
                                                        in females (HDT)
                                                       LOAEL = not
                                                        established
                                                       No evidence of
                                                        carcinogenicity
------------------------------------------------------------------------
870.4300                          Carcinogenicity     NOAEL = 1,134 mg/
                                    mice                kg/day in males,
                                                        1,422 mg/kg/day
                                                        in females (HDT)
                                                       LOAEL = not
                                                        established
                                                       No evidence of
                                                        carcinogenicity
------------------------------------------------------------------------
870.5265                          Gene mutation       Non-mutagenic when
                                                        tested up to
                                                        5,000 g/
                                                        plate, in
                                                        presence and
                                                        absence of
                                                        activation, in S.
                                                        typhimurium
                                                        strains TA98,
                                                        TA100, TA1535 and
                                                        TA1537 and E.coli
                                                        strain WP2uvra.
------------------------------------------------------------------------
870.5300                          Gene mutation       Non-mutagenic at
                                                        the HGPRT locus
                                                        in Chinese
                                                        hamster ovary
                                                        (CHO) cells
                                                        tested up to
                                                        cytotoxic
                                                        concentrations or
                                                        limit of
                                                        solubility, in
                                                        presence and
                                                        absence of
                                                        activation.
------------------------------------------------------------------------
870.5375                          Chromosome          Did not induce
                                    aberration          structural
                                                        chromosome
                                                        aberration in CHO
                                                        cell cultures in
                                                        the presence and
                                                        absence of
                                                        activation.
------------------------------------------------------------------------
870.5385                          Chromosomal         Non-mutagenic in
                                    aberration          rat bone marrow
                                                        chromosomal
                                                        aberrations assay
                                                        up to 5,000 mg/
                                                        kg.
------------------------------------------------------------------------
870.7485                          Metabolism and      Total recovery of
                                    pharmacokinetics -  the administered
                                     rat                dose was 98-106%
                                                        at 7 days.
                                                        Urinary excretion
                                                        was the major
                                                        route of
                                                        elimination (94-
                                                        102% of the
                                                        dose), with only
                                                        unchanged parent
                                                        detected. There
                                                        was no evidence
                                                        of
                                                        bioaccumulation
                                                        in the tissues.
                                                        There were no sex-
                                                         or dose-related
                                                        differences
                                                        following oral or
                                                        intravenous
                                                        administration.
------------------------------------------------------------------------

B. Toxicological Endpoints

     The dose at which no adverse effects are observed (the NOAEL) from
the toxicology study identified as appropriate for use in risk
assessment is used to estimate the toxicological level of concern
(LOC). However, the lowest dose at which adverse effects of concern are
identified (the LOAEL) is sometimes used for risk assessment if no
NOAEL was achieved in the toxicology study selected. An uncertainty
factor (UF) is applied to reflect uncertainties inherent in the
extrapolation from laboratory animal data to humans and in the
variations in sensitivity among members of the human population as well
as other unknowns. An UF of 100 is routinely used, 10X to account for
interspecies differences and 10X for intraspecies differences. Because
a developmental neurotoxicity study is not needed, there are currently
no residential uses, dietary exposure assessments will not
underestimate the potential exposures for infants and children, and the
toxicology database is complete, no additional FQPA Safety Factor (FQPA
SF) is required.
     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 imazapic used for human risk assessment is shown in the
following Table 2:

        Table 2.--Summary of Toxicological Dose and Endpoints for 
Imazapic 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 (general population and  None                     An 
acute dietary         None
  females 13-50 years old) 
endpoint was not
 
selected based on the
                                                                  absence of an
 
appropriate endpoint
 
attributed to a single
                                                                  dose
----------------------------------------------------------------------------------------------------------------
Chronic dietary (all populations)      LOAEL= 137 mg/kg/day     FQPA 
SF = 1X             LOAEL = 137 mg/kg/day
                                        UF = 300...............  cPAD 
= cRfD/FQPA.......   based on increased
                                        Chronic RfD = 0.5 mg/kg/ SF = 
0.5 mg/kg/day.....   incidence of minimal
                                         day. 
degeneration and/or
 
necrosis of skeletal
 
muscle in 1 year dog
 
feeding study
----------------------------------------------------------------------------------------------------------------
Incidental oral, short-term (1-7       Oral NOAEL = 350 mg/kg/  LOC = 
100                LOAEL = 500 mg/kg/day
  days)                                  day 
based on decreased
 
body weight and food
 
consumption during the
 
dosing period in
 
rabbit developmental
 
study
----------------------------------------------------------------------------------------------------------------
Incidental oral, intermediate-term (7  Oral NOAEL = 350 mg/kg/  LOC = 
100                LOAEL = 500 mg/kg/day
  days-several months)                   day 
based on decreased
 
body weight and food
 
consumption during the
 
dosing period in
 
rabbit developmental
 
study
----------------------------------------------------------------------------------------------------------------
Short- and intermediate-term dermal    None                     No 
systemic toxicity     None
  (1-7 days and 1 week-several months)                            was 
seen following
(Occupational)....................... 
repeated dermal
 
application at 1,000
 
mg/kg/day over a 3-
                                                                  week 
period. Since no
 
hazard was identified,
 
quantification is not
                                                                  required.
----------------------------------------------------------------------------------------------------------------
Long-term dermal (several months-      Oral LOAEL = 137 mg/kg/  LOC 
for MOE = 300        LOAEL = 137 mg/kg/day
  lifetime)                              day (dermal absorption 
based on increased
(Occupational).......................   rate = 50%) 
incidence of minimal
 
degeneration and/or
 
necrosis of skeletal
 
muscle in 1 year dog
 
feeding study
----------------------------------------------------------------------------------------------------------------
Short- and intermediate-term           Oral study NOAEL= 350    LOC 
for MOE = 100        LOAEL = 500 mg/kg/day
  inhalation (1-7 days and 1 week-       mg/kg/day (inhalation 
based on decreased
  several months)                        absorption rate = 
body weight and food
(Occupational).......................   100%) 
consumption during
 
dosing in rabbit
                             
developmental study
----------------------------------------------------------------------------------------------------------------
Long-term inhalation (several months-  Oral study LOAEL= 137    LOC 
for MOE = 300        LOAEL = 137 mg/kg/day
  lifetime)                              mg/kg/day (inhalation 
based on increased
(Occupational).......................   absorption rate = 
incidence of minimal
                                         100%) 
degeneration and/or
 
necrosis of skeletal
 
muscle in 1 year dog
 
feeding study
----------------------------------------------------------------------------------------------------------------
Cancer (oral, dermal, inhalation)      Cancer classification    Risk 
assessment not      No evidence of
                                         (``Group E'') 
required                 carcinogenicity
----------------------------------------------------------------------------------------------------------------

C. Exposure Assessment

     1. Dietary exposure from food and feed uses. Tolerances have been
established (40 CFR 180.490(a) for the combined residues of imazapic
and its metabolites CL 263284 and CL 189215, in or on peanut, nutmeat
at 0.1 ppm. Time-limited tolerances set to expire December 31, 2001 are
established under (40 CFR 180.490(b) in connection with section 18
emergency exemptions (99NE0009) for residues of imazapic and its
metabolites CL 263284 and CL 189215 for grass, forage at 30 ppm; grass,
hay at 15 ppm; milk at 0.10 ppm; fat, meat, and meat byproducts (except
kidney) of cattle, goats, hogs, horses, and sheep at 0.10 ppm; and
kidney of cattle, goats, hogs, horses, and sheep at 1.0 ppm. The
present analyses included the published peanut values together with re-
evaluated tolerance levels for livestock-derived commodities, based on
the new grass use proposed. Risk assessments were conducted by EPA to
assess dietary exposures from imazapic 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 1 day or single
exposure. An acute exposure assessment is not applicable based on the
absence of an appropriate effect of concern.
     ii. Chronic exposure. In conducting this chronic dietary risk
assessment the Dietary Exposure Evaluation Model (DEEMTM
version 7.73) 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: Residues present at tolerance
levels, 100% of each crop is treated, and the use of default processing
concentration factors (Tier 1 analysis).
     iii. Cancer. A cancer risk assessment was not conducted, since
imazapic has been classified as a ``Group E'' chemical (evidence of
non-carcinogenicity for humans) based upon lack of evidence of
carcinogenicity in two adequate studies (rats and mice).
     2. Dietary exposure from drinking water. The Agency lacks
sufficient monitoring exposure data to complete a comprehensive dietary
exposure analysis and risk assessment for imazapic 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 imazapic.
     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 Screening Concentrations in Ground Water (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 imazapic they are further
discussed in the aggregate risk sections below.
     Based on the FIRST and SCI-GROW models, the EECs of imazapic for
acute exposures are estimated to be 17 parts per billion (ppb) for
surface water and 14 ppb for ground water. The EECs for chronic
exposures are estimated to be 1.5 ppb for surface water and 14 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).
     Imazapic is not registered for use on any sites that would result
in residential exposure.
     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 imazapic 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,
imazapic 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 imazapic 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 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. Based on the available data,
no evidence of increased susceptibility was seen in the rat and rabbit
prenatal toxicity studies or following prenatal/postnatal exposure in
the 2-generation reproduction study.
     3. Conclusion. There is a complete toxicity data base for imazapic
and exposure data are complete or are estimated based on data that
reasonably account for potential exposures. EPA determined that the 10X
safety factor to protect infants and children should be removed. The
FQPA factor is removed because: A developmental neurotoxicity study is
not needed; there are currently no residential uses; and dietary
exposure assessments will not underestimate the potential exposures for
infants and children.

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

[[Page 66330]]

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, OPP concludes with reasonable certainty that
exposures to the pesticide in drinking water (when considered along
with other sources of exposure for which OPP has reliable data) would
not result in unacceptable levels of aggregate human health risk at
this time. Because OPP considers the aggregate risk resulting from
multiple exposure pathways associated with a pesticide's uses, levels
of comparison in drinking water may vary as those uses change. If new
uses are added in the future, OPP will reassess the potential impacts
of residues of the pesticide in drinking water as a part of the
aggregate risk assessment process.
     1. Acute risk. Imazapic is not expected to pose an acute risk
because no acute endpoint of concern was identified in the toxicity
test.
     2. Chronic risk. Using the exposure assumptions described in this
unit for chronic exposure, EPA has concluded that exposure to imazapic
from food will utilize 0.1% of the cPADs for the U.S. population, all
infants, and children 1-6 years old. There are no residential uses for
imazapic that result in chronic residential exposure to imazapic. In
addition, there is potential for chronic dietary exposure to imazapic
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 Imazapic Residues
----------------------------------------------------------------------------------------------------------------
 
Surface       Ground
               Population Subgroup                cPAD mg/kg/ 
%cPAD      Water EEC    Water EEC     Chronic
                                                      day 
(Food)       (ppb)        (ppb)     DWLOC (ppb)
----------------------------------------------------------------------------------------------------------------
U.S. population                                          0.5 
0.000269          1.5           14       17,000
----------------------------------------------------------------------------------------------------------------
All infants (< 1 year old)                               0.5 
0.000505          1.5           14        5,000
----------------------------------------------------------------------------------------------------------------
Children (1-6 years old)                                 0.5 
0.000684          1.5           14        5,000
----------------------------------------------------------------------------------------------------------------

     3. Short- or intermediate-term risk. Since there are no registered
uses for imazapic which would result in non-dietary, non-occupational
exposure, contributions to the aggregate risk from both short- and
intermediate-term non-dietary exposures are not expected.
     4. Aggregate cancer risk for U.S. population. Imazapic has been
classified as a ``Group E'' chemical (evidence of non-carcinogenicity
for humans); therefore imazapic is not expected to pose a cancer risk.
     5. 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 imazapic residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

     Adequate independent method validation (ILV) studies have been
submitted in support of all methods. A method which is similar to the
peanut enforcement method has been submitted for the determination of
residues of imazapic and its metabolites CL 263284 and CL 189215 in/on
grass forage and hay, and methods for the enforcement of tolerances of
imazapic and CL 263284 in milk and livestock tissues and an HPLC/MS
method for the enforcement of tolerances in fat have been submitted.

B. International Residue Limits

     There are no CODEX, Canadian, or Mexican maximum residue limits
(MRLs) for imazapic residues.

C. Conditions

     The registrant has committed to conduct four side-by-side grass
field trials using the maximum rate WDG acid formulation. The
registrant has also agreed to conduct four additional grass field
trials reflecting a single postemergence application of the 2 lb acid
equivalence (ae)/gal ammonium salt SC formulation at 0.1875 lb ae/A;
these trials will be conducted in Regions 7 and 8. The registrant also
is required to conduct a 28-day inhalation toxicity study, using the
protocol for the existing 90-day inhalation toxicity study. The results
of this study will provide a basis from which to determine more
reliable route-specific Margins of Exposure (MOEs) for worker
inhalation risks rather than the less reliable route-to-route MOE
calculations currently being used.

V. Conclusion

     Therefore, the tolerance is established for combined residues of
the herbicide imazapic and its hydroxymethyl metabolite, both free (CL
263284) and conjugated (CL 189215) in or on the raw agricultural
commodities grass, forage at 30 ppm, and grass, hay at 15 ppm.
Tolerances are also established for the combined residues of imazapic
and its free hydroxymethyl metabolite in or on milk at 0.1 ppm; fat,
meat, and meat byproducts (except kidney) of cattle, goats, horses, and
sheep at 0.1 ppm; and kidney of cattle, goats, horses, and sheep at 1.0
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-301198 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 February
25, 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 control number OPP-301198, 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: December 11, 2001.
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 180.490 is amended by revising paragraph (a) and
removing and reserving the text of paragraph (b) to read as follows:

Sec. 180.490  Imazapic-ammonium; tolerances for residues.

     (a) General. (1) Tolerances are established for combined residues
of the herbicide imazapic, ()-2-[4,5-dihydro-4-methyl-4-(1-
methylethyl)-5-oxo-1H-imidazol-2-yl]-5-methyl-3-pyridinecarboxylic acid
and its metabolite ()-2-[4,5-dihydro-4-methyl-4-(1-
methylethyl)-5-oxo-1H-imidazol-2-yl]-5-hydroxymethyl-3-
pyridinecarboxylic acid, both free and conjugated, in or on the
following food commodities:


----------------------------------------------------------------------------------------------------------------
                             Commodity 
Parts per million
----------------------------------------------------------------------------------------------------------------
Grass, forage.................................................... 
15
Grass, hay....................................................... 
30
Peanut nutmeat................................................... 
0.1
----------------------------------------------------------------------------------------------------------------

     (2) Tolerances are also established for the combined residues of
the herbicide imazapic, ()-2-[4,5-dihydro-4-methyl-4-(1-
methylethyl)-5-oxo-1H-imidazol-2-yl]-5-methyl-3-pyridinecarboxylic acid
and its free metabolite ()-2-[4,5-dihydro-4-methyl-4-(1-
methylethyl)-5-oxo-1H-imidazol-2-yl]-5-hydroxymethyl-3-
pyridinecarboxylic acid, in or on the following food commodities:


----------------------------------------------------------------------------------------------------------------
                             Commodity 
Parts per million
----------------------------------------------------------------------------------------------------------------
Cattle, fat...................................................... 
0.10
Cattle, kidney................................................... 
1.0
Cattle, mbyp (except kidney)..................................... 
0.1
Cattle, meat..................................................... 
0.1
Goats, fat....................................................... 
0.1
Goats, kidney.................................................... 
1.0
Goats, mbyp (except kidney)...................................... 
0.1
Goats, meat...................................................... 
0.1
Horses, fat...................................................... 
0.1
Horses, kidney................................................... 
1.0
Horses, mbyp (except kidney)..................................... 
0.1
Horses, meat..................................................... 
0.1
Milk............................................................. 
0.1

[[Page 66333]]

Sheep, fat....................................................... 
0.1
Sheep, kidney.................................................... 
1.0
Sheep, mbyp (except kidney)...................................... 
0.1
Sheep, meat...................................................... 
0.1
----------------------------------------------------------------------------------------------------------------

     (b) Section 18 emergency exemptions. [Reserved]
* * * * *

[FR Doc. 01-31493 Filed 12-21-01; 8:45 am]