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triallate (Avadex BW, Far-Go) Pesticide Tolerance 9/00


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[Federal Register: September 29, 2000 (Volume 65, Number 190)]
[Rules and Regulations]
[Page 58375-58385]
>From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr29se00-10]

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

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-301063; FRL-6744-8]
RIN 2070-AB78


Triallate,(S-2,3,3-trichloroallyl diisopropylthiocarbamate);
Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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

SUMMARY: This regulation establishes a tolerance for the combined
residues of the herbicide triallate (S-2,3,3, trichloroallyl
diisopropylthiocarbamate) and its metabolite, TCPSA (2,3,3-
trichloroprop-2-ene sulfonic acid) in or on sugar beet, root; sugar
beet, top; and sugar beet, pulp. Monsanto 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-301063,
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-301063 in the
subject line on the first page of your response.

FOR FURTHER INFORMATION CONTACT:  By mail: James A. Tompkins (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 @epamail.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
Registerlistings at http://www.epa.gov/fedrgstr/. 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-301063. 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 May 16, 1997 (62 FR 27027) (FRL-5717-6),
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 8F2128) for tolerance by Monsanto,
600 13th St., NW., Suite 660, Washington, DC 20005. This notice
included a summary of the petition prepared by Monsanto, the
registrant. There were no comments received in response to the notice
of filing.
    The petition requested that 40 CFR 180.314 be amended by
establishing a tolerance for residues of the herbicide triallate, and
its metabolite, TCPSA in or on sugar beet root at 0.01 part per million
(ppm), sugar beet top at 0.5 ppm, and sugar beet pulp at 0.2 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

[[Page 58376]]

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 residues of the herbicide triallate and
its metabolite, TCPSA in or on sugar beet root at 0.01 ppm, sugar beet
top at 0.5 ppm, and sugar beet pulp at 0.2 ppm. EPA's assessment of
exposures and risks associated with establishing the tolerance follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its
validity, completeness, and reliability as well as the relationship of
the results of the studies to human risk. EPA has also considered
available information concerning the variability of the sensitivities
of major identifiable subgroups of consumers, including infants and
children. The nature of the toxic effects caused by triallate (S-2,3,3,
trichloroallyl diisopropylthiocarbamate) are discussed in the following
Table 1 as well as the no observed adverse effect level (NOAEL) and the
lowest observed adverse effect level (LOAEL) from the toxicity studies
reviewed.

            Table 1.--Subchronic, Chronic and Other Toxicity
------------------------------------------------------------------------
         Guideline No.               Study Type            Results
------------------------------------------------------------------------
870.3100                         90-Day oral         NOAEL = 5 mg/kg/day
                                  toxicity in
                                  rodents Rat
                                                     LOAEL = 25 mg/kg/
                                                      day based on
                                                      decreased body
                                                      weight in males
                                                      and females,
                                                      slight anemia in
                                                      females (decreased
                                                      red blood cells,
                                                      hematocrit and
                                                      hemoglobin) and
                                                      histopathology of
                                                      the kidney in
                                                      males (tubular
                                                      epithelial
                                                      regeneration and
                                                      nephropathy).
------------------------------------------------------------------------
870.3200                         21-Day dermal       NOAEL = 500 mg/kg/
                                  toxicity in         day
                                  rodents Rat
                                                     LOAEL = 3,000 mg/kg/
                                                      day based on body
                                                      weight gain
                                                      decreases,
                                                      relative kidney
                                                      and liver weight
                                                      increases,
                                                      increased presence
                                                      of basophillic
                                                      tubules of the
                                                      renal cortex, and
                                                      alpha 2 -globulin
                                                      inclusions in the
                                                      proximal
                                                      convoluted renal
                                                      tubules in rats.
------------------------------------------------------------------------
870.3465                         Subchronic          NOAEL = less than
                                  inhalation          2.62 mg/kg/day,
                                  toxicity Rat        not established
                                                     LOAEL = 2.62 mg/kg/
                                                      day based on
                                                      histological
                                                      changes in kidney
                                                      (nephropathy and
                                                      tubular epithelial
                                                      regeneration).
------------------------------------------------------------------------
870.3700                         Prenatal            Maternal NOAEL = 10
                                  developmental       mg/kg/day
                                  toxicity in
                                  rodents Rat
                                                     LOAEL = 30 mg/kg/
                                                      day based on
                                                      decreases in body
                                                      weight gain and
                                                      food consumption.
                                                      Developmental
                                                      NOAEL = 30 mg/kg/
                                                      day
                                                     LOAEL = 90 mg/kg/
                                                      day based on
                                                      decreased fetal
                                                      body weight,
                                                      external
                                                      malformations
                                                      (protruding
                                                      tongue) and
                                                      skeletal
                                                      variations.
------------------------------------------------------------------------
870.3700                         Prenatal            Maternal NOAEL = 15
                                  developmental       mg/kg/day
                                  toxicity in
                                  nonrodents Rabbit
                                                     LOAEL = 45 mg/kg/
                                                      day based on
                                                      clinical signs and
                                                      decreases in body
                                                      weight gain.
                                                     Developmental NOAEL
                                                      = 5 mg/kg/day
                                                     LOAEL = 15 mg/kg/
                                                      day based on
                                                      decreased fetal
                                                      body weight and
                                                      increased skeletal
                                                      variations.
------------------------------------------------------------------------
870.3800                         Reproduction and    Parental/Systemic
                                  fertility effects   NOAEL = 7.5 mg/kg/
                                  Rat                 day
                                                     LOAEL = 30 mg/kg/
                                                      day based on
                                                      maternal
                                                      mortality,
                                                      increased
                                                      incidences of
                                                      chronic nephritis,
                                                      head bobbing,
                                                      circling movements
                                                      and reduced body
                                                      weight.
                                                     Reproductive NOAEL
                                                      = 7.5 mg/kg/day
                                                     LOAEL = 30 mg/kg/
                                                      day based on based
                                                      on increased
                                                      neonatal mortality
                                                      during the F2b
                                                      litter interval,
                                                      reduced pup
                                                      weights at birth
                                                      during the F2b
                                                      litter interval,
                                                      reduced pup
                                                      weights in late
                                                      lactation for all
                                                      litters, reduced
                                                      pregnancy rate and
                                                      shortened
                                                      gestation length.
------------------------------------------------------------------------
870.4100                         Chronic toxicity    NOAEL = 2.5 mg/kg/
                                  Dog                 day
                                                     LOAEL = 15.0 mg/kg/
                                                      day based on
                                                      increased alkaline
                                                      phosphatase levels
                                                      at all time
                                                      intervals in male
                                                      and female dogs.
------------------------------------------------------------------------
870.4100                         Chronic toxicity    NOAEL = 1.5 mg/kg/
                                  Dog                 day
                                                     LOAEL = 5.0 mg/kg/
                                                      day based on
                                                      increased
                                                      hemosiderin
                                                      deposition in the
                                                      spleen, increased
                                                      serum alkaline
                                                      phosphatase and
                                                      increased liver
                                                      weight in females.
------------------------------------------------------------------------
870.4200                         Combined chronic    NOAEL = 2.5 mg/kg/
                                  toxicity/           day
                                  carcinogenicity
                                  Rat
                                                     LOAEL = 12.5 mg/kg/
                                                      day based on
                                                      decreased survival
                                                      (males and
                                                      females),
                                                      decreased body
                                                      weight (males) and
                                                      increased adrenal
                                                      weight (males).

[[Page 58377]]

                                                     Evidence of
                                                      carcinogenicity:
                                                      Renal tubular
                                                      adenomas in male
                                                      rats.
------------------------------------------------------------------------
870.4200                         Combined chronic    NOAEL = (males) 3
                                  toxicity/           mg/kg/day
                                  carcinogenicity
                                  Mouse
                                                     LOAEL = (males) 9
                                                      mg/kg/day based on
                                                      increased absolute
                                                      liver weight,
                                                      increased
                                                      incidence of
                                                      altered foci of
                                                      the liver and
                                                      hematopoiesis in
                                                      the spleen.
                                                     NOAEL (females) =
                                                      37.5 mg/kg/day
                                                     LOAEL (females)
                                                      >37.5 mg/kg/day,
                                                      not established
------------------------------------------------------------------------
                                                     Evidence of
                                                      carcinogenicity:
                                                      Increased
                                                      incidence of
                                                      hepatocellular
                                                      carcinomas and
                                                      hepatocellular
                                                      adenomas (males).
------------------------------------------------------------------------
870.4200                         Combined chronic    NOAEL = (males) 50
                                  toxicity/           ppm
                                  carcinogenicity
                                  Hamster
                                                     LOAEL = (males) 300
                                                      ppm based on
                                                      decreased
                                                      triglyceride
                                                      levels (males and
                                                      females)
------------------------------------------------------------------------
870.5100                         Gene Mutation in    Positive. Triallate
                                  Salmonella          induced a
                                  typhimurium.        mutagenic response
                                                      in Salmonella
                                                      typhimuriumstrains
                                                      TA1535 and TA100
                                                      at noncytotoxic
                                                      doses of 0.1
                                                      g/plate
                                                      and above -S9
                                                      activation and
                                                      TA1535, TA98 and
                                                      TA100 at 0.001
                                                      g/plate
                                                      and above +S9. In
                                                      tester strains
                                                      TA1537 and TA1538,
                                                      there were no
                                                      appreciable
                                                      increases in
                                                      revertant colonies
                                                      of evidence of
                                                      cytotoxicity at
                                                      any dose.
                                                      Mutagenesis was
                                                      confirmed in a
                                                      repeat test with
                                                      Salmonella
                                                      typhimurium
                                                      strainTA1535 at
                                                      dose levels of 1,
                                                      5, and 10 g/plate +/- S9
                                                      activation.
------------------------------------------------------------------------
870.5300                         Gene Mutation/In    Negative. Triallate
                                  vitro mammalian     did not induce
                                  cell assay in       forward gene
                                  mouse lymphoma      mutations at the
                                  cells Negative.     thymidine kinase
                                                      (TK+-) locus in
                                                      L51784 mouse
                                                      lymphoma cells at
                                                      concentration of
                                                      0.005 to 0.04
                                                      l/ml in
                                                      the absence or
                                                      presence of
                                                      metabolic
                                                      activation.
------------------------------------------------------------------------
870.5300                         Gene Mutation/In    Positive. Triallate
                                  vitro mammalian     induced forward
                                  cell assay in       gene mutations at
                                  mouse lymphoma      the thymidine
                                  cells               kinase (TK+/-)
                                                      locus in L51784
                                                      mouse lymphoma
                                                      cells. The
                                                      frequency of gene
                                                      mutations was
                                                      greater than or
                                                      equal to a two-
                                                      fold increase and
                                                      occurred at
                                                      noncytotoxic
                                                      concentrations of
                                                      60 g/ml -
                                                      S9 activation and
                                                      21 and 24 7mu;g/ml
                                                      +S9 activation.
------------------------------------------------------------------------
870.5385                         Cytogenetics/In     Negative. There was
                                  vivo hamster        no evidence of
                                  micronucleus        either a
                                  assay               clastogenic or
                                                      aneugenic effect
                                                      in male and female
                                                      hamsters fed
                                                      dietary
                                                      concentrations of
                                                      0, 600, 2,000 or
                                                      6,000 ppm
                                                      Triallate at any
                                                      sacrifice time.
------------------------------------------------------------------------
870.5395                         Cytogenetics/In     Negative. There was
                                  vivo mouse          no evidence of
                                  micronucleus        either a
                                  assay               clastogenic or
                                                      aneugenic effect
                                                      in male and female
                                                      mice administered
                                                      70, 350, or 700 mg/
                                                      kg Triallate at
                                                      any sacrifice
                                                      time.
------------------------------------------------------------------------
870.5550                         Other Mutagenic     Negative. Triallate
                                  Mechanisms/In       did not induce a
                                  vitro unscheduled   genotoxic effect
                                  DNA synthesis in    in primary rat
                                  primary rat         hepatocytes at
                                  hepatocytes         concentrations of
                                                      5, 10, 50, 100,
                                                      500 and 1,000
                                                      g/mL.
------------------------------------------------------------------------
870.5550                         Other Mutagenic     Negative. There was
                                  Mechanisms/In       no evidence that
                                  vivo In vitro       Triallate induce
                                  unscheduled DNA     either a cytotoxic
                                  synthesis in        or genotoxic
                                  primary rat         response a any
                                  hepatocytes         dose (50, 250 or
                                                      500 mg/kg) or
                                                      sacrifice time (92
                                                      or 16 hours).
------------------------------------------------------------------------
870.5900                         Other Mutagenic     Positive. Triallate
                                  Mechanisms/In       induced
                                  vitro sister        significant
                                  chromatid           increases in the
                                  exchange in         number of sister
                                  Chinese hamster     chromatid
                                  ovary cells         exchanges per cell
                                                      at concentrations
                                                      of 1.6 x 10-5M to
                                                      8.1 x 10-5M -S9
                                                      activation and 0.8
                                                      x 10-5M to 4.0 x
                                                      10-5M +S9
                                                      activation after
                                                      either a two or
                                                      four hour exposure
                                                      period,
                                                      respectively.
                                                      Repeat assays
                                                      conducted for 30
                                                      hours at
                                                      concentrations up
                                                      to 40.4 x 10-5M -
                                                      S9 activation and
                                                      for 2 hours at
                                                      concentrations up
                                                      to 12.1 x 10-5M
                                                      +S9 activation
                                                      confirmed these
                                                      findings.
------------------------------------------------------------------------
870.6100                         Acute delayed       Systemic NOAEL less
                                  neurotoxicity Hen   than 312.5 mg/kg,
                                                      not established
                                                     LOAEL = 312.5 mg/kg
                                                      based on acute,
                                                      reversible
                                                      clinical signs
                                                      (muscle weakness/
                                                      paralysis,
                                                      salivation and
                                                      involuntary neck
                                                      movement).
                                                      Triallate did not
                                                      induce delayed
                                                      peripheral
                                                      neuropathy.
------------------------------------------------------------------------
870.6200                         Acute               NOAEL = 60 mg/kg
                                  neurotoxicity
                                  screening battery
                                  Rat

[[Page 58378]]

                                                     LOAEL = 300 mg/kg
                                                      based on decreased
                                                      body weight gain
                                                      and alterations in
                                                      motor activity.
------------------------------------------------------------------------
870.6200                         Subchronic          NOAEL = 6.38/8.14
                                  neurotoxicity       mg/kg/day for male/
                                  screening battery   female rats
                                  Rat
                                                     LOAEL = 32.9/38.9
                                                      mg/kg/day for male/
                                                      female rats based
                                                      on decreased body
                                                      weights, body
                                                      weight gains, food
                                                      consumption and
                                                      lesions (nerve
                                                      fiber
                                                      degeneration) in
                                                      the central and
                                                      peripheral nervous
                                                      systems.
------------------------------------------------------------------------
870.6200                         Subchronic          Neurotoxic NOAEL =
                                  neurotoxicity       134.32 mg/kg/day
                                  screening battery
                                  Rat
                                                     LOAEL = 223.79 mg/
                                                      kg/day based on
                                                      behavioral effects
                                                      (histopathology
                                                      for axonal
                                                      degeneration was
                                                      not conducted at
                                                      this dose level).
                                                      At 295 mg/kg/day,
                                                      nuerohistopatholog
                                                      ical lesions
                                                      occurred in both
                                                      the central and
                                                      peripheral nerves.
                                                      Systemic NOAEL =
                                                      34.64 mg/kg/day
                                                     LOAEL = 134.32 mg/
                                                      kg/day based on
                                                      decreased body
                                                      weight and food
                                                      consumption and
                                                      food efficiency.
------------------------------------------------------------------------
870.6300                         Developmental       Maternal NOAEL = 30
                                  neurotoxicity Rat   mg/kg/day
                                                     LOAEL = 60 mg/kg/
                                                      day based on
                                                      reductions in body
                                                      weight gains and
                                                      food consumption.
                                                     Developmental
                                                      Neurotoxicity
                                                      NOAEL = 30 mg/kg/
                                                      day
                                                     LOAEL = 60 mg/kg/
                                                      day based [on
                                                      increased motor
                                                      activity.
------------------------------------------------------------------------
870.7485                         Metabolism and      General metabolism
                                  pharmacokinetics
                                  Rat
                                                     Analysis of whole
                                                      body elimination
                                                      in male and female
                                                      rats indicated
                                                      that 85% of the
                                                      radiolabeled
                                                      triallate was
                                                      excreted within 24
                                                      hours of dosing.
                                                      Most radioactivity
                                                      was excreted in
                                                      approximately
                                                      equal amounts
                                                      (42%) in the urine
                                                      and feces of male
                                                      rats after 10
                                                      days. Females
                                                      excreted 51% in
                                                      urine and 32% in
                                                      feces after 10
                                                      days. Males and
                                                      females retained
                                                      about 0.4% of the
                                                      dose in organs and
                                                      tissues and
                                                      approximately 2%
                                                      in the remaining
                                                      carcass. The
                                                      distribution of
                                                      radioactivity in
                                                      both sexes
                                                      indicated that the
                                                      greatest amount of
                                                      activity was found
                                                      in the red blood
                                                      cells followed by
                                                      whole blood,
                                                      spleen, kidney,
                                                      liver and lung.
------------------------------------------------------------------------
870.7485                         Metabolism and      General metabolism
                                  pharmacokinetics
                                  Rat
                                                     Seven metabolites,
                                                      in concentrations
                                                      of greater than
                                                      one percent, were
                                                      identified in rat
                                                      urine; 2,3,3-
                                                      trichloro-2-
                                                      propenesulfinic
                                                      acid (20-27%), N-
                                                      acetyl-S-(2,2-
                                                      dichloro-1-[methyl-
                                                      sufonyl)
                                                      methyl]ethenyl)-L-
                                                      cysteine (6-11%),
                                                      (E)-S-(2carboxy-2-
                                                      chloroethenyl)-L-
                                                      cysteine (4-5%),
                                                      carbon dioxide
                                                      (4%), 2,3,3-
                                                      trichloro-propene
                                                      sulfonic acid (3-
                                                      5%), (E)-3-
                                                      ((carboxymethyl)th
                                                      io)-2-chloro-2-
                                                      propenoic acid (1-
                                                      3%), and 1-((3,3,2-
                                                      trichloro-2-
                                                      propenyl)thio)-
                                                      beta-D-glucuronic
                                                      acid. The
                                                      remaining
                                                      metabolites were
                                                      found at less than
                                                      1% of the
                                                      administered dose.
------------------------------------------------------------------------
Special studies                  Assessment of the   Data from this
                                  kidney for alpha    study is
                                  2          considered a
                                  globulins in the    preliminary
                                  rat subchronic      indication that
                                  and chronic         triallate may be
                                  feeding studies     classified as an
                                                      alpha 2
                                                      globulin type
                                                      nephrotoxin.
                                                      Additional data
                                                      and analysis
                                                      considered
                                                      necessary for a
                                                      more conclusive
                                                      decision.
------------------------------------------------------------------------

    Several acute toxicology studies place technical triallate in acute
toxicity category III for acute oral toxicity and primary eye
irritation and in toxicity category IV for acute dermal toxicity, acute
inhalation toxicity, and primary dermal irritation. Triallate is a skin
sensitizer.

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 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.

[[Page 58379]]

    For non-dietary risk assessments (other than cancer) the UF is used
to determine the LOC. For example, when 100 is the appropriate UF (10X
to account for interspecies differences and 10X for intraspecies
differences) the LOC is 100. To estimate risk, a ratio of the NOAEL to
exposures (margin of exposure (MOE) = NOAEL/exposure) is calculated and
compared to the LOC.
    The linear default risk methodology (Q*) is the primary method
currently used by the Agency to quantify carcinogenic risk. The Q*
approach assumes that any amount of exposure will lead to some degree
of cancer risk. A Q* is calculated and used to estimate risk which
represents a probability of occurrence of additional cancer cases
(e.g., risk is expressed as 1 x 10-6 or one in a million).
Under certain specific circumstances, MOE calculations will be used for
the carcinogenic risk assessment. In this non-linear approach, a
``point of departure '' is identified below which carcinogenic effects
are not expected. The point of departure is typically a NOAEL based on
an endpoint related to cancer effects though it may be a different
value derived from the dose response curve. To estimate risk, a ratio
of the point of departure to exposure (MOE cancer = point of
departure/exposures) is calculated. A summary of the toxicological
endpoints for triallate (S-2,3,3-trichloroallyl
diisopropylthiocarbamate) used for human risk assessment is shown in
the following Table 2:

           Table 2.--Summary of Toxicological Dose and Endpoints for triallate (S-2,3,3-trichloroallyl
                           diisopropylthiocarbamate) 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 = 5 mg/kg/day, UF  FQPA SF = 3, aPAD =      Developmental toxicity
 age                                    = 100, Acute RfD =       acute RfDFQPA    study -Rabbits
                                        0.05 mg/kg/day           SF = 0.017 mg/kg/day
                                                                                         Developmental LOAEL =
                                                                                          15 mg/kg/day based on
                                                                                          decreased fetal body
                                                                                          weight and increased
                                                                                          skeletal variations.
----------------------------------------------------------------------------------------------------------------
Acute Dietary general population       NOAEL = 60 mg/kg/day,    FQPA SF = 1 aPAD =       Acute Neurotoxicity-Rat
 including infants and children         UF = 100, Acute RfD =    acute RfD FQPA
                                        0.60 mg/kg/day           SF = 0.60 mg/kg/day
                                                                                         LOAEL = 300 mg/kg/day
                                                                                          based on decreased
                                                                                          body weight and
                                                                                          alterations in motor
                                                                                          activity
----------------------------------------------------------------------------------------------------------------
Chronic Dietary all populations        NOAEL = 2.5 mg/kg/day,   FQPA SF = 1, cPAD =      Chronic Toxicity/
                                        UF = 100, Chronic RfD    chronic RfD      Carcinogenicity-Rat
                                        = 0.025 mg/kg/day        FQPA SF = 0.025 mg/kg/
                                                                 day
                                                                                         LOAEL = 12.5 mg/kg/day
                                                                                          based on decreased
                                                                                          survival in males and
                                                                                          females, decreased
                                                                                          body weight in males,
                                                                                          increased adrenal
                                                                                          weight in males
----------------------------------------------------------------------------------------------------------------
Short- Term Dermal (1 to 7 days)       oral study NOAEL= 5 mg/  LOC for MOE = 100        Developmental Toxicity
 (Residential)                          kg/day (dermal           (Residential)             Rabbit LOAEL = 15 mg/
                                        absorption rate = 1%)                             kg/day based on
                                                                                          Increased skeletal
                                                                                          malformations/
                                                                                          variations
----------------------------------------------------------------------------------------------------------------
Intermediate-Term Dermal (1 week to    (oral) study NOAEL = 5   LOC for MOE = 100        Developmental Toxicity-
 several months) (Residential)          mg/kg/day (dermal        (Residential)            Rabbit LOAEL = 15 mg/
                                        absorption rate = 1%                              kg/day based on
                                                                                          Increased skeletal
                                                                                          malformations/
                                                                                          variations
----------------------------------------------------------------------------------------------------------------
Long-Term Dermal (several months to    Dermal (or oral) study   LOC for MOE = none       none
 lifetime) (Residential)                NOAEL= none mg/kg/day    (Residential)
                                        (dermal absorption
                                        rate = none% when
                                        appropriate)
                                                                                         LOAEL = none mg/kg/day
                                                                                          based on none Not
                                                                                          identified, continuous
                                                                                          exposure greater than
                                                                                          180 days not expected
----------------------------------------------------------------------------------------------------------------
Short-Term Inhalation (1 to 7 days)    inhalation (or oral)     LOC for MOE = 100        Developmental toxicity-
 (Residential)                          study NOAEL= 5 mg/kg/    (Residential)            Rabbit
                                        day (inhalation
                                        absorption rate = 100%

                                                                                         LOAEL = 15 mg/kg/day
                                                                                          based on Increased
                                                                                          skeletal malformations/
                                                                                          variations
----------------------------------------------------------------------------------------------------------------
Intermediate-Term Inhalation (1 week   inhalation (or oral)     LOC for MOE = 100        Developmental toxicity-
 to several months) (Residential)       study NOAEL = 5 mg/kg/   (Residential)            Rabbit
                                        day (inhalation
                                        absorption rate = 100%
                                                                                         LOAEL = 15 mg/kg/day
                                                                                          based on Increased
                                                                                          skeletal malformations/
                                                                                          variations
----------------------------------------------------------------------------------------------------------------

[[Page 58380]]

Long-Term Inhalation (several months   inhalation (or oral)     LOC for MOE = none       none LOAEL = none mg/kg/
 to lifetime)(Residential)              study NOAEL= none mg/    (Residential)            day based on none
                                        kg/day (inhalation
                                        absorption rate = 100%
                                                                                         Not identified,
                                                                                          continuous exposure
                                                                                          greater than 180 days
                                                                                          not expected
----------------------------------------------------------------------------------------------------------------
Cancer (oral, dermal, inhalation)        .....................    .....................  Q*7.17 x 10-2(mg/kg/
                                                                                          day)-1
                                         .....................    .....................  Group C chemical-likely
                                                                                          to be a human
                                                                                          carcinogen
----------------------------------------------------------------------------------------------------------------
*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 180.314(a)) for residues of the herbicide triallate
(S-2,3,3, trichloroallyl diisopropylthiocarbamate), per se (parent
only) in or on a variety of raw agricultural commodities; Barley,
grain; Barley, straw; Lentils; Lentils, forage; Lentils, hay; Peas,
forage; Peas, hay; Wheat, grain; and Wheat, straw. Under
reregistration, the triallate tolerance expression will be revised in
order to reflect the Agency's determination that triallate and its
TCPSA metabolite should be regulated and assessed for dietary exposure
in plant commodities. The Agency decided to regulate on the TCPSA
metabolite because it is present at more than 10% of the total
radioactive residue (TRR) in the plant metabolism studies. Tolerances
are to be expressed as triallate for the combined residues of the
herbicide triallate (S-2,3,3-S-2,3,3-trichloroallyl
diisopropylthiocarbamate) and its metabolite TCPSA (2,3,3-
trichloroprop-2-ene sulfonic acid) in or on the following commodities:
Sugar Beet, root; Sugar Beet, top; and Sugar Beet, pulp. No tolerances
have been established for processed food/feed or animal commodities.
Risk assessments were conducted by EPA to assess dietary exposures from
triallate (S-2,3,3-trichloroallyl diisopropylthiocarbamate) and its
metabolite TCPSA 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 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. A probalistic (Monte Carlo) acute
dietary analysis was conducted for triallate residues in food. This
analysis is highly refined (Tier 3), and represents a realistic
estimate of acute dietary exposure in food possible with current data,
based on all uses supported through reregistration and the proposed
used of triallate on sugar beets. The percent acute population adjusted
doses (PADs) are significantly below the Agency's level of concern at
the 99.9th percentile of exposure for the females 13+ subgroup (<2%
aPAD) and for the general population (<1% aPAD). For acute dietary
analyses, anticipated residues and percent of crop treated data were
used. For the purposes of this assessment, residue field trial data
were used for the acute anticipated residues calculations.
    ii. Chronic exposure . In conducting the 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 the chemical for each commodity. The chronic
(non-cancer) dietary risk from exposure through food is <1% of the
Agency's level of concern (<100% of the chronic PAD) for the general
U.S. population and all subgroups. For chronic dietary analyses,
anticipated residues and percent of crop treated data were used. For
the purposes of this assessment, residue field trial data were used for
the chronic anticipated residue calculations.
    iii. Cancer. Triallate is classified as a Group C chemical
(possible human carcinogen), based on hepatocellular carcinomas in male
mice, with a positive trend and borderline significance in female mice,
and increased incidence of renal tubular cell adenomas in rats. A
linear low-dose (Q1*) approach was used to
characterize human health risk. The unit risk,
Q1*based on the hepatocellular carcinomas in male
mice, is 7.17 x 10-2(mg/kg/day)-1in human
equivalents. The Agency generally considers risks in the range of 1 x
10-6(1 in 1 million) or less as negligible risk for cancer
dietary exposure. The results of this analysis indicate that the cancer
dietary risk of 7.1 x 10-8from exposure through food,
associated with the uses supported through reregistration and the
proposed use of triallate on sugar beets, is below the Agency's level
of concern for food alone.
    iv. Anticipated residue and percent crop treated information.
Section 408(b)(2)(E) authorizes EPA to use available data and
information on the anticipated residue levels of pesticide residues in
food and the actual levels of pesticide chemicals that have been
measured in food. If EPA relies on such information, EPA must require
that data be provided 5 years after the tolerance is established,
modified, or left in effect, demonstrating that the levels in food are
not above the levels anticipated. Following the initial data
submission, EPA is authorized to require similar data on a time frame
it deems appropriate. As required by section 408(b)(2)(E), EPA will
issue a data call-in for information relating to anticipated residues
to be submitted no later than 5 years from the date of issuance of this
tolerance.
    Section 408(b)(2)(F) states that the Agency may use data on the
actual percent of food treated for assessing chronic dietary risk only
if the Agency can make the following findings: Condition 1, that the
data used are reliable and provide a valid basis to show what
percentage of the food derived from such crop is likely to contain such
pesticide residue;

[[Page 58381]]

Condition 2, that the exposure estimate does not underestimate exposure
for any significant subpopulation group; and Condition 3, if data are
available on pesticide use and food consumption in a particular area,
the exposure estimate does not understate exposure for the population
in such area. In addition, the Agency must provide for periodic
evaluation of any estimates used. To provide for the periodic
evaluation of the estimate of percent crop treated (PCT) as required by
section 408(b)(2)(F), EPA may require registrants to submit data on
PCT.
    A routine chronic dietary exposure analysis for triallate and its
metabolite (TCPSA) was based on percent crop treated (PCT) information
as follows:

------------------------------------------------------------------------
          Acute Estimated Maximum             Chronic Weighted Average
------------------------------------------------------------------------
Barley 13%................................  Barley 9%
Barley bran 13%...........................  Barley bran 9%
Barley flour 13%..........................  Barley flour 9%
Dry pea 30%...............................  Dry pea 13%
Sugar beet dried pulp 21%.................  Sugar beet dried pulp 21%
Sugar beet molasses 21%...................  Sugar beet molasses 21%
Sugar beet root 21%.......................  Sugar beet root 21%
Sugar beet tops 21%.......................  Sugar beet tops 21%
Sugar beet sugar 21%......................  Sugar beet sugar 21%
Wheat bran 8%.............................  Wheat bran 6%
Wheat flour 8%............................  Wheat flour 6%
Wheat grain 8%............................  Wheat grain 6%
Wheat mill by-products 8%.................  Wheat mill by-products 6%
Wheat shorts 8%...........................  Wheat shorts 6%
------------------------------------------------------------------------

    The Agency believes that the three conditions listed above have
been met. With respect to Condition 1, PCT estimates are derived from
Federal and private market survey data, which are reliable and have a
valid basis. EPA uses a weighted average PCT for chronic dietary
exposure estimates. This weighted average PCT figure is derived by
averaging State-level data for a period of up to 10 years, and
weighting for the more robust and recent data. A weighted average of
the PCT reasonably represents a person's dietary exposure over a
lifetime, and is unlikely to underestimate exposure to an individual
because of the fact that pesticide use patterns (both regionally and
nationally) tend to change continuously over time, such that an
individual is unlikely to be exposed to more than the average PCT over
a lifetime. For acute dietary exposure estimates, EPA uses an estimated
maximum PCT. The exposure estimates resulting from this approach
reasonably represent the highest levels to which an individual could be
exposed, and are unlikely to underestimate an individual's acute
dietary exposure. The Agency is reasonably certain that the percentage
of the food treated is not likely to be an underestimation. As to
Conditions 2 and 3, regional consumption information and consumption
information for significant subpopulations is taken into account
through EPA's computer-based model for evaluating the exposure of
significant subpopulations including several regional groups. Use of
this consumption information in EPA's risk assessment process ensures
that EPA's exposure estimate does not understate exposure for any
significant subpopulation group and allows the Agency to be reasonably
certain that no regional population is exposed to residue levels higher
than those estimated by the Agency. Other than the data available
through national food consumption surveys, EPA does not have available
information on the regional consumption of food to which triallate S-
2,3,3-trichloroallyl diisopropylthiocarbamate may be applied in a
particular area.
    2. Dietary exposure from drinking water. The Agency lacks
sufficient exposure data to complete a comprehensive dietary exposure
analysis and risk assessment for triallate and its metabolite TCPSA 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
environmental fate and transport and physical characteristics of
triallate and TCPSA.
    The Agency uses the Generic Estimated Environmental Concentration
(GENEEC) and the Pesticide Root Zone/EXposure Analysis Modeling System
(PRZM/EXAMS) to produce estimates of pesticides in surface source
drinking water. The Screening-concentration in ground water (SCI-GROW)
model was used to estimate concentrations in shallow groundwater. The
primary use of the models by the Agency is to screen out pesticides
with low potential of reaching concentrations in drinking water
exceeding human health levels of concern. EPA will use GENEEC (a tier 1
model) before using PRZM/EXAMS (a tier 2 model). The GENEEC model was
designed to simulate runoff from a 10 hectare (ha) field into a static
1 ha small water body. It was originally designed to assess pesticide
concentrations in aquatic environments for ecological risk assessments.
The PRZM/EXAMS model scenario is designed as a refined screening model
which incorporates a watershed scale assessment with a flow-through
index reservoir. Additionally, the PRZM/EXAMS modeling incorporates a
percent cropped area (PCA) to account for the extent of cropping area
within a watershed. None of the models consider the impact of water
treatment (mixing, dilution, or treatment) on pesticide concentrations
in raw water. In cases where the screening model predictions exceed
human health levels of concern, the Agency will require targeted
monitoring studies to assess the actual pesticide concentrations in
drinking water.
    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 Percent of Reference Dose (%RfD)
or Percent of Population Adjusted Dose (%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 triallate and its metabolite TCPSA, 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 triallate and its metabolite
TCPSA in surface water and ground water for acute exposures are
estimated to be 9.452 parts per billion (ppb) for surface water and
0.21 ppb for ground water. The EECs for chronic (non-cancer) exposures
are estimated to be 1.26 ppb for surface water and 0.21 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).
    Triallate 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

[[Page 58382]]

residues and ``other substances that have a common mechanism of
toxicity.''
    EPA does not have, at this time, available data to determine
whether triallate 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,
triallate 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 triallate 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. Safety factor for infants and children-- i. 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.
    ii. Prenatal and postnatal sensitivity. Quantitatively, there is
evidence of increased susceptibility in the prenatal developmental
toxicity study in rabbits; developmental effects (decreased fetal body
weight and increased incidence of malaligned sternebrae) were observed
in the absence of maternal toxicity.
    iii. Conclusion. There is a complete toxicity data base for
triallate and exposure data are complete or are estimated based on data
that reasonably accounts for potential exposures--EPA determined that
some additional safety factor was needed to protect infants and
children because the toxicity data indicated increased sensitivity to
the young. The FQPA factor was reduced to 3x because the toxicology
data base is complete; increased sensitivity was observed in only one
species (rabbits); there is no quantitative or qualitative indication
of increased susceptibility in the prenatal developmental toxicity
study in rats, the 2-generation reproduction study in rats, or the
developmental neurotoxicity in rats; adequate data are available or
conservative modeling assumptions are used to assess dietary food and
drinking water exposure; and there are currently no registered
residential uses for triallate.

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 groundwater 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. Using the exposure assumptions discussed in this
unit for acute exposure, the acute dietary exposure from food to
triallate, and its metabolite, TCPSA will occupy <1% of the aPAD for
the U.S. population, 1.8% of the aPAD for females 13 years and older,
<1% of the aPAD for all infants (<1 year) and <1% of the aPAD for
children (1-6 years). In addition, there is potential for acute dietary
exposure to triallate and its metabolite TCPSA 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 the following Table 3:

                Table 3.--Aggregate Acute Risk Assessment for Triallate and its Metabolite TCPSA
----------------------------------------------------------------------------------------------------------------
                                                                                           Ground
       Population Subgroup         aPAD (mg/kg)      %aPAD (Food)    Surface Water EEC   Water EEC   Acute DWLOC
                                                                           (ppb)           (ppb)        (ppb)
----------------------------------------------------------------------------------------------------------------
U.S.Population                              0.60                 <1                9.4         0.21       21,000
----------------------------------------------------------------------------------------------------------------
Children (1-6 years)                        0.60                 <1                9.4         0.21        6,000
----------------------------------------------------------------------------------------------------------------
Females (13+ nursing)                      0.017                1.8                9.4         0.21          500
----------------------------------------------------------------------------------------------------------------

    2. Chronic risk . Using the exposure assumptions described in this
unit for chronic exposure, EPA has concluded that exposure to triallate
and its metabolite, TCPSA from food will utilize <1% of the cPAD for
the U.S.

[[Page 58383]]

population, <1% of the cPAD for Non-nursing infants (<1 year old) and
<1% of the cPAD for children (1-6 years old). There are no residential
uses for triallate and its metabolite TCPSA that result in chronic
residential exposure to triallate and its metabolite TCPSA, as shown in
the following Table 4:

 Table 4.--Aggregate Chronic Risk Assessment for Chronic (Non-Cancer) Exposure to triallate and its metabolite,
                                                      TCPSA
----------------------------------------------------------------------------------------------------------------
                                                                             Surface       Ground
           Population Subgroup               cPAD mg/kg/day      %cPAD      Water EEC    Water EEC     Chronic
                                                                 (Food)       (ppb)        (ppb)     DWLOC (ppb)
----------------------------------------------------------------------------------------------------------------
U.S. Population                                        0.025           <1         1.26         0.21          875
----------------------------------------------------------------------------------------------------------------
Females (13+, nursing)                                 0.025           <1         1.26         0.21          250
----------------------------------------------------------------------------------------------------------------
Children (1-6 years)                                   0.025           <1         1.26         0.21          750
----------------------------------------------------------------------------------------------------------------

    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).
    Triallate is not registered for use on any sites that would result
in residential exposure. Therefore, the aggregate risk is the sum of
the risk from food and water, which do not exceed the Agency's level of
concern.
    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).
    Triallate is not registered for use on any sites that would result
in residential exposure. Therefore, the aggregate risk is the sum of
the risk from food and water, which do not exceed the Agency's level of
concern.
    5. Aggregate cancer risk for U.S. population. The Agency generally
considers risks in the range of 1 x 10-6(1 in 1 million) or
less as negligible risk for cancer. The results of this analysis
indicate that the cancer dietary (food) risk estimate of 7.1 x
10-8associated with the uses supported through
reregistration and the proposed use on sugar beets is not of concern.
The cancer DWLOC is 0.45 ppb. The Tier II (PRZM-EXAMS) estimated
average concentration of triallate + TCPSA in surface water is 0.566
ppb (mean annual with 2 incorporation) and 1.26 ppb (mean annual with
no incorporation). Concentrations in ground water are not expected to
be higher than 0.21 ppb. The 36-year annual mean estimated
concentrations in surface water exceed the DWLOCs for triallate + TCPSA
in drinking water as a contribution to cancer aggregate exposure.
However, the drinking water component is based on model predictions,
which are generally conservative in estimating chemical concentrations
in drinking water. To address this concern, the registrant initiated a
3-year surface drinking water monitoring study in June 1999 to measure
raw and finished triallate + TCPSA concentrations at five surface
drinking water collection locations. Interim results of the surface
water monitoring study indicated that peak and mean exposure to total
parent triallate and TCPSA at all five sites are below the cancer DWLOC
(0.45 ppb). Additional monitoring data will be provided on a quarterly
basis, with a final report of the study expected in late 2002. Based on
the interim results of the surface water monitoring study, which
indicated that peak and mean exposure to total parent triallate and
TCPSA are below the cancer DWLOC (0.45 ppb), the aggregate cancer risk
for the U.S. Population is expected to be less than 1 x
10-6.
    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 triallate and its metabolite (TCPSA) combined residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    In conjunction with the regional registration of triallate on sugar
beets, the registrant has proposed a GC/ECD method (designated as
Method RES-099-96, Version No. 2) for tolerance enforcement purposes.
The method determines residues of triallate and its TCPSA metabolite.
This method has been subjected to a successful independent laboratory
validation. The method has also been validated in an Agency study at
Beltsville, MD. The laboratory (Analytical Chemistry Branch, BEAD)
verified the limits of quantitation (LOQs) to be 0.025 ppm triallate
and 0.025 ppm TCPSA in/on sugar beet roots, and 0.05 ppm triallate and
0.20 ppm TCPSA in/on sugar beet foliage. The Beltsville report (7/28/
98) also estimated the limits of detection (LODs) to be 0.001 ppm
triallate and 0.004 ppm TCPSA in sugar beet root, and 0.005 ppm
triallate and 0.04 ppm TCPSA in sugar beet top. The expected dietary
burdens of triallate to beef/dairy cattle and poultry animals were
recalculated following tolerance reassessment of livestock feed items.
There is no reasonable expectation of finite residues (Category 3 of 40
CFR section 180.6); therefore, tolerances are not required for milk,
eggs, and animal tissues.
    Adequate enforcement methodology is available to enforce the
tolerance expression. 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 MRLs for triallate; therefore, no questions of
compatibility with U.S. tolerances exists.

C. Conditions

    Completion of the 3-year surface drinking water study will be a
condition of registration. Monitoring data will be provided on a
quarterly basis, with a final report of the study expected in late
2002.

V. Conclusion

    Therefore, the tolerance is established for the combined residues
of the herbicide triallate (S-2,3,3, trichloroallyl
diisopropylthiocarbamate) and its metabolite, TCPSA (2,3,3-
Trichloroprop-2-ene sulfonic acid) in or on sugar beet, root, sugar
beet, top, and sugar beet pulp.

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

[[Page 58384]]

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-301063 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-301063, 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 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 (58 FR 51735, October 4, 1993). This final rule does not contain
any information collections subject to OMB approval under the Paperwork
Reduction Act (PRA), 44 U.S.C. 3501 et seq., or impose any enforceable
duty or contain any unfunded mandate as described under Title II of the
Unfunded Mandates Reform Act of 1995 (UMRA) (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 (63 FR 27655, May 19, 1998); special considerations as
required by Executive Order 12898, entitled Federal Actions to Address
Environmental Justice in Minority Populations and Low-Income
Populations (59 FR 7629, February 16, 1994); or require OMB review 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

[[Page 58385]]

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).

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 180.314 is revised to read as follows:

Sec. 180.314  Triallate; tolerances for residues.

    (a) General. Tolerances are established for residues of the
herbicide (S-2,3,3-trichloroallyl diisopropylthiocarbamate) in or on
the following raw agricultural commodities:

------------------------------------------------------------------------
                   Commodity                        Parts per million
------------------------------------------------------------------------
Barley, grain..................................                     0.05
Barley, straw..................................                     0.05
Lentils........................................                     0.05
Lentils, hay...................................                     0.05
Peas...........................................                     0.05
Peas, forage...................................                     0.05
Peas, hay......................................                     0.05
Wheat, grain...................................                     0.05
Wheat, straw...................................                     0.05
------------------------------------------------------------------------

    (b) Section 18 emergency exemptions. [Reserved]
    (c) Tolerances with regional registrations. Tolerances are
established for residues of the herbicide triallate (S-2,3,3-
trichloroallyl diisopropylthiocarbamate) and its metabolite 2,3,3-
trichloroprop-2-enesulfonic acid in or on the following food
commodities:

------------------------------------------------------------------------
                   Commodity                        Parts per million
------------------------------------------------------------------------
Sugar beet, pulp...............................                      0.2
Sugar beet, root...............................                      0.1
Sugar beet, top................................                      0.5
------------------------------------------------------------------------

    (d) Indirect or inadvertent residues. [Reserved]

[FR Doc. 00-24942 Filed 9-28-00; 8:45 a.m.]
BILLING CODE 6560-50-S
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Last Modified: 10/19/2000
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