[Federal Register Volume 69, Number 185 (Friday, September 24, 2004)]
[Rules and Regulations]
[Pages 57197-57207]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-21501]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[OPP-2004-0315; FRL-7680-1]


Dimethenamid; Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes a tolerance for residues of 
dimethenamid in or on onions (dry bulb), garlic, shallots (dry bulb), 
tuberous and corm vegetables, sugar beets, garden beets, and 
horseradish. Interregional Research Project No. 4 (IR-4) requested 
these tolerances under the Federal Food, Drug, and Cosmetic Act 
(FFDCA), as amended by the Food Quality Protection Act of 1996 (FQPA). 
In addition, this regulatory action is part of the tolerance 
reassessment requirements of section 408(q) of the FFDCA 21 U.S.C. 
346a(q), as amended by the FQPA of 1996. By law, EPA is required to 
reassess all tolerances in existence on August 2, 1996 by August 2006. 
This regulatory action will count for thirteen reassessments towards 
this August 2006 deadline.

DATES: This regulation is effective September 24, 2004. Objections and 
requests for hearings must be received on or before November 23, 2004.

ADDRESSES: To submit a written objection or hearing request follow the 
detailed instructions as provided in Unit VI. of the SUPPLEMENTARY 
INFORMATION. EPA has established a docket for this action under Docket 
identification (ID) number OPP-2004-0315. All documents in the docket 
are listed in the EDOCKET index at http://www.epa.gov/edocket. Although 
listed in the index, some information is not publicly available, i.e., 
CBI or other information whose disclosure is restricted by statute. 
Certain other material, such as copyrighted material, is not placed on 
the Internet and will be publicly available only in hard copy form. 
Publicly available docket materials are available either electronically 
in EDOCKET or in hard copy at the Public Information and Records 
Integrity Branch (PIRIB), Rm. 119, Crystal Mall <greek-i>2, 1801 South 
Bell St., Arlington, VA. This docket facility is open from 8:30 a.m. to 
4 p.m., Monday through Friday, excluding legal holidays. The docket 
telephone number is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: Jim Tompkins, Registration Division 
(7505C), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave., NW.,Washington, DC 20460-0001; telephone 
number: (703) 305-5697; e-mail address: <a href="/cdn-cgi/l/email-protection#8df9e2e0fde6e4e3fea3e7e4e0cde8fdeca3eae2fb"><span class="__cf_email__" data-cfemail="02766d6f72696b6c712c686b6f426772632c656d74">[email protected]</span></a>.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

    You may be potentially affected by this action if you are an 
agricultural producer, food manufacturer, or pesticide manufacturer. 
Potentially affected entities may include, but are not limited to:
    <bullet> Crop production (NAICS 111), e.g., agricultural workers; 
greenhouse, nursery, and floriculture workers; farmers.
    <bullet> Animal production (NAICS 112), e.g., cattle ranchers and 
farmers, dairy cattle farmers, livestock farmers.
    <bullet> Food manufacturing (NAICS 311), e.g., agricultural 
workers; farmers; greenhouse, nursery, and floriculture workers; 
ranchers; pesticide applicators.
    <bullet> Pesticide manufacturing (NAICS 32532), e.g., agricultural 
workers; commercial applicators; farmers; greenhouse, nursery, and 
floriculture workers; residential users.
    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 this unit could also be 
affected. The North American Industrial Classification System (NAICS) 
codes have been provided to assist you and others in determining 
whether this action might apply to certain entities. If you have any 
questions regarding the applicability of this action to a particular 
entity, consult the person listed under FOR FURTHER INFORMATION 
CONTACT.

[[Page 57198]]

B. How Can I Access Electronic Copies of this Document and Other 
Related Information?

    In addition to using EDOCKET (http://www.epa.gov/edocket/), you may 
access this Federal Register document electronically through the EPA 
Internet under the ``Federal Register'' listings at http://www.epa.gov/fedrgstr/. A frequently updated electronic version of 40 CFR part 180 
is available at E-CFR Beta Site Two at http://www.gpoaccess.gov/ecfr/. 
To access the OPPTS Harmonized Guidelines referenced in this document, 
go directly to the guidelines at http://www.epa.gpo/opptsfrs/home/guidelin.htm/.

II. Background and Statutory Findings

    In the Federal Register of March 12, 2003 (68 FR11850) (FRL-7295-
9), EPA issued a notice pursuant to section 408(d)(3) of the FFDCA, 21 
U.S.C. 346a(d)(3), announcing the filing of a pesticide petition (PP 
0E6196) by Interregional Research Project No. 4 (IR-4), Technology 
Centre of New Jersey, Rutgers, the State University of New Jersey, 681 
U.S. Highway <greek-i>1 South, North Brunswick, NJ 08902-3390. The 
petition requested that 40 CFR 180.464 be amended by establishing a 
tolerance for residues of the herbicide dimethenamid, (R,S)-2-chloro-N-
[(1-methyl-2-methoxy) ethyl]-N-(2,4-dimethyl-thien-3-yl)-acetamide, in 
or on onions (dry bulb), garlic, shallots (dry bulb), tuberous and corm 
vegetables, sugar beets, garden beets, and horseradish at 0.01 parts 
per million (ppm). That notice included a summary of the petition 
prepared by IR-4, the registrant. There were no comments received in 
response to the notice of filing.
    Dimethenamid was originally registered as a mixture of R and S-
isomers (50:50, S:R), and tolerances for the 50:50 mixture were 
established for dry beans, field corn, sweet corn, peanuts, sorghum, 
and soybean. Manufacture of the 50:50 mixture has ceased and has been 
replaced by a mixture (dimethenamid-P) that is enriched in the 
biologically active S-isomer (90:10, S:R). Registration of the original 
50:50 mixture will be cancelled when existing stock is depleted. 
Currently, both dimethenamid (50:50, S:R) and dimethenamid-P (90:10, 
S:R) are used. The petition sought to have tolerances established on a 
non-isomer specific bases. The existing toxicological and residue 
chemistry databases are established primarily on studies conducted with 
the 50:50 mixture. To address the uncertainty concerning qualitative or 
quantitative toxicological difference(s) between the original 50:50 
mixture and the enriched 90:10 mixture, EPA reviewed several 
toxicological studies conducted using both products. EPA concluded that 
the dimethenamid toxicology database is adequate for the risk 
assessment of both dimethenamid and dimethenamid-P. Therefore, 40 CFR 
180.464 is being revised to include tolerances for residues resulting 
from application of both dimethenamid (50:50, S:R) and dimethenamid-P 
(90:10, S:R).
    In addition, existing tolerances for dimethenamid were reassessed 
as part of the tolerance reassessment requirements of section 408(q) of 
the FFDCA 21 U.S.C. 346a(q), as amended by the FQPA of 1996. By law, 
EPA is required to reassess all tolerances in existence on August 2, 
1996 by August 2006.
    Section 408(b)(2)(A)(i) of 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) of FFDCA 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) of FFDCA requires EPA to give special 
consideration to exposure of infants and children to the pesticide 
chemical residue in establishing a tolerance and to ``ensure that there 
is a reasonable certainty that no harm will result to infants and 
children from aggregate exposure to the pesticide chemical 
residue....''
    EPA performs a number of analyses to determine the risks from 
aggregate exposure to pesticide residues. For further discussion of the 
regulatory requirements of section 408 of FFDCA 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) of FFDCA, 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) of FFDCA, for a tolerance for residues of dimethenamid on 
onions (dry bulb), garlic, shallots (dry bulb), tuberous and corm 
vegetables, sugar beets, garden beets, and horseradish at 0.01 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 dimethenamid are 
discussed in Table 1. of this unit 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
----------------------------------------------------------------------------------------------------------------
870.1100                                 Acute oral/rats [Sprague    LD50 = 429 mg/kg for males LD50 = 531 mg/kg
                                          Dawley] dimethenamid-P      for females
                                          (90:10 S:R isomers)        LD50 = 480 mg/kg for both sexes
                                                                     Toxicity category II
----------------------------------------------------------------------------------------------------------------
870.1100                                 Acute oral/rats [Sprague    LD50 = 500 mg/kg. The mean for both sexes
                                          Dawley] dimethenamid       Toxicity category II
                                          (50:50 S:R isomers)
----------------------------------------------------------------------------------------------------------------

[[Page 57199]]

 
870.1200                                 Acute dermal/rabbits        LD50 = > 2,000 mg/kg
                                          dimethenamid-P (90:10 S:R  Toxicity category III
                                          isomers)
----------------------------------------------------------------------------------------------------------------
870.1200                                 Acute dermal/rabbits        LD50 = > 2,000 mg/kg
                                          dimethenamid (50:50 S:R    Toxicity category III
                                          isomers)
----------------------------------------------------------------------------------------------------------------
870.1300                                 Acute inhalation [Sprague   LC50 = 2.2 mg/L
                                          Dawley] dimethenamid-P     Toxicity category III
                                          (90:10 S:R isomers)
----------------------------------------------------------------------------------------------------------------
870.1300                                 Acute inhalation/rats       LC50 = 4.99 mg/L
                                          [Wistar] dimethenamid      Toxicity category III
                                          (50:50 S:R isomers)
----------------------------------------------------------------------------------------------------------------
870.2400                                 Acute eye irritation        Minimally irritating
                                          rabbits dimethenamid-P     Toxicity category III
                                          (90:10 S:R isomers)
----------------------------------------------------------------------------------------------------------------
870.2400                                 Acute eye irritation/       Minimally irritating
                                          rabbits dimethenamid       Toxicity category III
                                          (50:50 S:R isomers)
----------------------------------------------------------------------------------------------------------------
870.2500                                 Acute dermal irritation     Minimally irritating
                                          rabbits dimethenamid-P     Toxicity category IV
                                          (90:10 S:R isomers)
----------------------------------------------------------------------------------------------------------------
870.2500                                 Acute dermal irritation/    Minimally irritating
                                          rabbits dimethenamid       Toxicity category IV
                                          (50:50 S:R isomers)
----------------------------------------------------------------------------------------------------------------
870.2600                                 Skin sensitization [Guinea  Mild skin senstizer
                                          Pigs] dimethenamid-P
                                          (90:10 S:R isomers)
----------------------------------------------------------------------------------------------------------------
870.2600                                 Skin sensitization [Guinea  Mild skin senstizer
                                          Pigs] dimethenamid (50:50
                                          S:R isomers)
----------------------------------------------------------------------------------------------------------------
870.3100                                 Subchronic Feeding/Sprague  NOAEL= 37/40(M/F) mg/kg/day [500 ppm]
                                          Dawley Rat dimethenamid-P  LOAEL= 110/125 (M/F) mg/kg/day [1,500 ppm]
                                          (90:10 S:R isomers)         based on decreased body weight (bwt) and
                                                                      bwt gain in males and females, increased
                                                                      gamma-glutamyl transferase in both sexes,
                                                                      increased cholesterol in males, increased
                                                                      absolute and relative liver weight and
                                                                      periportal hepatocytic hypertrophy and
                                                                      periportal eosinophilic inclusions in
                                                                      males, centrilobular hypertrophy in
                                                                      females and liver necrosis in females
----------------------------------------------------------------------------------------------------------------
870.3100                                 Subchronic Feeding/Sprague  NOAEL= 33.5/40.1 (M/F) mg/kg/day [500 ppm]
                                          Dawley rat dimethenamid    LOAEL= 98/119 (m/f) mg/kg/day [1,500 ppm]
                                          (50:50 S:R isomers)         based on decreased bwt and bwt gain,
                                                                      increased total protein in males; in
                                                                      females, increased cholesterol, increased
                                                                      liver weight and centrilobular hepatocytic
                                                                      enlargement
----------------------------------------------------------------------------------------------------------------
870.3150                                 Subchronic oral toxicity    NOAEL = 4.72/4.98 (M/F) mg/kg/day [100 ppm
                                          (dog) dimethenamid (50:50   ]
                                          S:R isomers)               LOAEL = 33.6/39.7 (M/F) mg/kg/day [750 ppm]
                                                                      based on decreased bwt and bwt gain in
                                                                      females, increased relative liver weight
                                                                      in both sexes, increased periportal
                                                                      vacuolation in both sexes and dilation of
                                                                      liver sinusoids in females
----------------------------------------------------------------------------------------------------------------
870.3200                                 21/28-Day dermal toxicity   NOAEL = 50 mg/kg/day
                                          (rabbit) dimethenamid      LOAEL = 150 mg/kg/day based on decreased
                                          (50:50 S:R isomers)         blood phosphate in both sexes [15% at
                                                                      150mg/kg/day and 15% at 500 mg/kg/day] [p
                                                                      < 0.05]
----------------------------------------------------------------------------------------------------------------
870.3250                                 Subchronic dermal toxicity  Not required
                                          dimethenamid (50:50 S:R
                                          isomers)
----------------------------------------------------------------------------------------------------------------
870.3465                                 Subchronic inhalation       Not required
                                          toxicity es) dimethenamid
                                          (50:50 S:R isomers)
----------------------------------------------------------------------------------------------------------------

[[Page 57200]]

 
870.3700                                 Prenatal developmental in   Maternal NOAEL = None
                                          (Sprague Dawley rats)      LOAEL = 25 mg/kg/day based on bwt decrement
                                          dimethenamid-P (90:10 S:R   on Gestation Day 13-19(Gday) (no single
                                          isomers)                    dose effect) and body weight gain decrease
                                                                      and food consumption decrease GDay 6-16
                                                                      and 6-9, respectively
                                                                     Developmental NOAEL = 25 mg/kg/day
                                                                     LOAEL=150 mg/kg/day based on ossification
                                                                      delays in the pubis and at 300 mg/kg/day
                                                                      ossification delays in the pubis, sternal
                                                                      centra, incidences of microphthalmia,
                                                                      umbilical hernia and at 400 mg/kg/day
                                                                      increased post implantation loss in a
                                                                      range-finding study
----------------------------------------------------------------------------------------------------------------
870.3700                                 Prenatal developmental in   Maternal NOAEL = 50 mg/kg/day
                                          (Sprague Dawley rats)      LOAEL = 215 mg/kg/day based on bwt
                                          dimethenamid (50:50 S:R     decrement on GDay 12 (but not a single
                                          isomers)                    dose effect) and bwt decrement and food
                                                                      consumption decrease, both GDay 6-9 and 6-
                                                                      16
                                                                     Developmental NOAEL = 215 mg/kg/day
                                                                     LOAEL= 425 mg/kg/day based on increased
                                                                      post implantation loss
----------------------------------------------------------------------------------------------------------------
870.3700                                 Prenatal Developmental      Maternal NOAEL = 75 mg/kg/day
                                          (NZW/Rabbit) dimethenamid  LOAEL = 150 mg/kg/day based on slight bwt
                                          (50:50 S:R isomers)         decrement (80g, GDay 12-15), bwt loss (75g
                                                                      GDay 15-19) and 2 abortions and in a 20
                                                                      litter/group range-finding study, death
                                                                      (13/20) and abortions (7/20) at 250 mg/kg/
                                                                      day
                                                                     Developmental NOAEL = 75 mg/kg/day
                                                                     LOAEL = 150 mg/kg/day based on SS fetal
                                                                      incidence of irregular parietals and hyoid
                                                                      angulated. Litter incidence was nominally
                                                                      elevated by 50% and 100%, respectively,
                                                                      and nominally increase post implantation
                                                                      loss (double control)
----------------------------------------------------------------------------------------------------------------
870.3800                                 Reproduction and fertility  Parental/Systemic NOAEL = M/F 36/40 mg/kg/
                                          effects (Wistar             day [500 ppm]
                                          rats)dimethenamid (50:50   LOAEL =M/F 150/160 mg/kg/day [2,000 ppm]
                                          S:R isomers)                based on decrease bwt, bwt gain, food
                                                                      consumption and absolute and relative
                                                                      liver weight increase
                                                                     Reproductive NOAEL = M/F 150/160 mg/kg/day
                                                                      [2,000 ppm]
                                                                     LOAEL = None
                                                                     Offspring NOAEL = 40 mg/kg/day [500 ppm]
                                                                     LOAEL = 160 mg/kg/day [2,000 ppm] based on
                                                                      f1 pup weight decrement at LDay 21 and f2
                                                                      pup weight decrease at LDay day 7 and 2
----------------------------------------------------------------------------------------------------------------
870.4100                                 Chronic toxicity (Rat)      Satisfied by data for 870.4300
                                          dimethenamid (50:50 S:R
                                          isomers)
----------------------------------------------------------------------------------------------------------------
870.4100                                 Chronic toxicity (dog)      NOAEL = M/F 10.1/9.1 mg/kg/day [250 ppm]
                                          dimethenamid (50:50 S:R    LOAEL = M/F 48.7/49.3 mg/kg/day [1,250 ppm]
                                          isomers)                    based on decreased bwt and bwt gains [43%
                                                                      to 60%, 0-26 wk] both sexes 100% in males
                                                                      wk 26-52] alkaline phosphatase increased
                                                                      in females 109-2185 through out study and
                                                                      80% in males. Portal vacuolation in males;
                                                                      vacuoles not lipid or glycogen
----------------------------------------------------------------------------------------------------------------
870.4200                                 Carcinogenicity (rat        Satisfied by data for 870.4300
                                          dimethenamid (50:50 S:R
                                          isomers)
----------------------------------------------------------------------------------------------------------------
870.4200                                 Carcinogenicity (mouse)     NOAEL = 300 ppm (M/F: 40.8/40.1 mg/kg/day)
                                          dimethenamid (50:50 S:R    LOAEL = 1,500 ppm (M/F: 205/200 mg/kg/day)
                                          isomers)                    based on decreased bwt gain in both sexes
                                                                     No treatment related tumors were seen at
                                                                      adequate doses
----------------------------------------------------------------------------------------------------------------
870.4300                                 Chronic/carc-inogenicity    NOAEL = 100 ppm [M/F: 5.1/6.8 mg/kg/day]
                                          (Sprague Dawley rat)       LOAEL = 7,000 ppm [M/F: 36/49 mg/kg/day]
                                          dimethenamid (50:50 S:R     based on decreased bwt and bwt gain in
                                          isomers)                    both sexes and microscopic hepatic lesions
                                                                      in both sexes. A dose related increased
                                                                      incidence of liver tumors in males (benign
                                                                      and malignant combined) were seen at the
                                                                      1,500 ppm dose both exceeding slightly
                                                                      historical controls. Dimethenamid (50:50
                                                                      S:R isomers) characterized as a Group C -
                                                                      possible human carcinogen. For the purpose
                                                                      of risk assessment, the MOE approach will
                                                                      be used for human risk assessment)
----------------------------------------------------------------------------------------------------------------
870.5100                                 Bacterial Reverse mutation  S. typhimurium exposed to 500-4,000 [mu]g/
                                          dimethenamid-P (90:10 S:R   plate +/- S9
                                          isomers)                   E. coli exposed to 20-5,000 [mu]g/plate +/-
                                                                      S9 using the standard plate incorporation
                                                                      method or 4-2,500 [mu]g/plate +/- S9 using
                                                                      the pre-incubation modification to the
                                                                      standard test. Highest doses were
                                                                      cytotoxic
                                                                     All assays were negative
----------------------------------------------------------------------------------------------------------------

[[Page 57201]]

 
870.5100                                 Bacterial Reverse mutation  Exposed to 20-5,000 [mu]g/plate in a plate
                                          dimethenamid-P (90:10 S:R   incorporation assay. Marginal cytotoxicity
                                          isomers)                    at limit dose of 5,000 [mu]g/plate +/- S9
                                                                     Assays were negative with both bacteria +/-
                                                                      S9
----------------------------------------------------------------------------------------------------------------
870.5100                                 Bacterial Reverse mutation  Repeat of MRID <greek-i> 44123502. S.
                                          dimethenamid-P (90:10 S:R   typhimurium TA100 was exposed to 100-5,000
                                          isomers)                    [mu]g/plate +/- S9
                                                                     Assay was negative
----------------------------------------------------------------------------------------------------------------
870.5100                                 Bacterial Reverse mutation  Exposed to 100-5,000 [mu]g/plate, +/- S9,
                                          dimethenamid-P (90:10 S:R   in a plate incorporation assay.
                                          isomers)                    Insolubility seen at 333 and 5,000 [mu]g/
                                                                      plate, but no toxicity at any dose +/- S9
                                                                     Assays were negative with both bacteria +
                                                                      S9, however, - S9 induced 1.5 fold
                                                                      increases at 333 [mu]g/plate and 4.1 fold
                                                                      increases in reverents in TA100 strain at
                                                                      5000 [mu]g/plate. This mutagenic response
                                                                      was reproducible at 100 to 5,000 [mu]g/
                                                                      plate
----------------------------------------------------------------------------------------------------------------
870.5100                                 Bacterial Reverse mutation  Strains tested at 1000-10,000 [mu]g/plate,
                                          dimethenamid-P (90:10 S:R    S9 and 1,000-6,500 [mu]g/plate, + S9.
                                          isomers)                    Cytotoxicity and precipitation were noted
                                                                      at higher doses
                                                                     Test was negative, +/- S9
----------------------------------------------------------------------------------------------------------------
870.5300                                 Mammalian cell mutation     Chinese hamster ovary (CHO) cells were
                                          dimethenamid-P (90:10 S:R   exposed to 100-400 [mu]g/mL, - S9, and 100-
                                          isomers)                    450 [mu]g/mL, + S9. Slight cytotoxicity
                                                                      was seen at the highest dose and severe
                                                                      toxicity was seen at >= 500 [mu]g/mL
                                                                     Test was negative for mutagenic effects, +/-
                                                                       S9
----------------------------------------------------------------------------------------------------------------
870.5395                                 Mouse erythrocyte           CD-1 mice dosed at 710 mg/kg in two daily
                                          micronucleus test           doses. LD50 = 1,417 mg/kg. Bone marrow
                                          dimethenamid (50:50 S:R     erythrocytes harvested 24 and 48 hours
                                          isomers)                    later
                                                                     Test negative
----------------------------------------------------------------------------------------------------------------
870.5395                                 Mouse erythrocyte           Mice dosed 0-1,000 mg/kg in single doses.
                                          micronucleus test           Mice showed no toxicity; only one mouse
                                          dimethenamid (50:50 S:R     died
                                          isomers)                   Test negative
----------------------------------------------------------------------------------------------------------------
870.5375                                 Chromosomal aberration      Cells in 125-150 [mu]g/mL, - S9 and 400 to
                                          test dimethenamid (50:50    500 [mu]g/mL, + S9; all doses were
                                          S:R isomers)                cytotoxic. Study needs repeating at none
                                                                      cytotoxic doses.
                                                                     Test considered equivocally positive
----------------------------------------------------------------------------------------------------------------
870.5550                                 Unscheduled DNA             Cell in 1.0-100 nl/mL. No cytotoxicity was
                                          (deoxyribonucleic acid)     seen
                                          Synthesis (UDS) in rat     Test was negative
                                          hepatocytes dimethenamid
                                          (50:50 S:R isomers)
----------------------------------------------------------------------------------------------------------------
870.5550                                 UDS in rat hepatocytes      Fisher 344 rat administered SAN 582H doses
                                          dimethenamid (50:50 S:R     of 158 or 500 mg/kg. Sampled 2-4 and 12-14
                                          isomers)                    hours after dosing. Only 0.2-3.6% cells in
                                                                      repair, but negative control was less than
                                                                      zero
                                                                     Test was negative for UDS at 158 and 500 mg/
                                                                      kg
----------------------------------------------------------------------------------------------------------------
870.5550                                 UDS in rat hepatocytes      SAN 582H administered at 0.01 to 50 [mu]g/
                                          dimethenamid (50:50 S:R     mL. Unscheduled DNA synthesis was seen
                                          isomers)                    well below cytotoxic doses. Unequivocally
                                                                      positive for UDS
                                                                     Test positive
----------------------------------------------------------------------------------------------------------------
870.5550                                 UDS in rat hepatocytes      SAN 582H administered at 0.0128 to 1,000
                                          dimethenamid (50:50 S:R     [mu]g/mL to rat primary cultures of
                                          isomers)                    hepatocytes. Doses at 1,000 [mu]g/mL were
                                                                      cytotoxic. No UDS was noted
                                                                     Test negative for UDS
----------------------------------------------------------------------------------------------------------------
870.5450                                 Dominant Lethal             Male Charles River (CR) rats (40-55)
                                          dimethenamid (50:50 S:R     administered SAN 582H in single oral doses
                                          isomers)                    of 275, 550, or 1,100 mg/kg were mated
                                                                      starting at 10 weeks to 40-55 female
                                                                      undosed CR rats. Increased dead implants
                                                                      at week 1 and week 2 may suggest a
                                                                      dominant lethal effect. These were mostly
                                                                      late implant deaths, which some
                                                                      consultants claim are not characteristic
                                                                      of a dominant lethal effect
----------------------------------------------------------------------------------------------------------------
870.5450                                 Dominant Lethal             Male Sprague Dawley rats (40-60)
                                          dimethenamid (50:50 S:R     administered SAN 582H in single oral doses
                                          isomers)                    of 275, 550, or 1,100 mg/kg were mated
                                                                      starting the day after dosing in Trial 1
                                                                      and 2 days after dosing in Trial 2 to 80-
                                                                      120 female undosed Sprague Dawley rats .
                                                                      Each male was mated to 2 females over a
                                                                      five day sequence. Results equivocal
                                                                     Note: Both the high dose rabbit and rat
                                                                      developmental studies showed increased
                                                                      late and early resorptions
----------------------------------------------------------------------------------------------------------------

[[Page 57202]]

 
870.5375                                 Cytogenetics in CHO cells   CHO cells were exposed to 2-120 [mu]g/mL -
                                          dimethenamid-P(90:10 S:R    S9; cytotoxic at >= 120 [mu]g/mL. CHO
                                          isomers)                    cells were exposed to 15-120 [mu]g/mL +
                                                                      S9; cytotoxic at >= 500 [mu]g/mL
                                                                     Assay was negative +/- S9
----------------------------------------------------------------------------------------------------------------
870.5395                                 Cytogenetics; mouse         Mice (5/sex) were exposed to i.p.
                                          erythrocyte microncleus     injections of 103, 205, 410 mg/kg
                                          test dimethenamid-P        Assay was negative, indicating no
                                          (90:10 S:R isomers)         clastogenic or aneugenic response
----------------------------------------------------------------------------------------------------------------
870.5550                                 UDS in mammalian cell       Cells tested at 7.8-125 [mu]g/mL.
                                          culture dimethenamid-P      Cytotoxicity and insolubility were seen at
                                          (90:10 S:R isomers)         >= 250 [mu]g/mL
                                                                     Test was negative for UDS
----------------------------------------------------------------------------------------------------------------
870.6200                                 Acute neurotoxicity         Not required
                                          screening battery
                                          dimethenamid-P (90:10 S:R
                                          isomers)
----------------------------------------------------------------------------------------------------------------
870.6200                                 Acute neurotoxicity         Not required
                                          screening battery
                                          dimethenamid (50:50 S:R
                                          isomers)
----------------------------------------------------------------------------------------------------------------
870.6200                                 Subchronic neurotoxicity    Not required
                                          screening battery
                                          dimethenamid-P (90:10 S:R
                                          isomers)
----------------------------------------------------------------------------------------------------------------
870.6300                                 Developmental               Not required
                                          neurotoxicity
                                          dimethenamid-P (90:10 S:R
                                          isomers)
----------------------------------------------------------------------------------------------------------------
870.7485                                 Metabolism and              Not required
                                          pharmacokinetics
                                          (species) dimethenamid-P
                                          (90:10 S:R isomers)
----------------------------------------------------------------------------------------------------------------
870.7600                                 Dermal penetration          Not required
                                          (species) dimethenamid-P
                                          (90:10 S:R isomers)
----------------------------------------------------------------------------------------------------------------
870.7600                                 Dermal penetration          Not required
                                          (species) dimethenamid
                                          (50:50 S:R isomers)
----------------------------------------------------------------------------------------------------------------

B. Toxicological Endpoint

    The dose at which no adverse effects are observed (the NOAEL) from 
the toxicology study identified as appropriate for use in risk 
assessment is used to estimate the toxicological level of concern 
(LOC). However, the lowest dose at which adverse effects of concern are 
identified (the LOAEL) is sometimes used for risk assessment if no 
NOAEL was achieved in the toxicology study selected. An uncertainty 
factor (UF) is applied to reflect uncertainties inherent in the 
extrapolation from laboratory animal data to humans and in the 
variations in sensitivity among members of the human population as well 
as other unknowns. An UF of 100 is routinely used, 10X to account for 
interspecies differences and 10X for intraspecies differences.
    Three other types of safety or uncertainty factors may be used: 
``Traditional uncertainty factors;'' the ``special FQPA safety 
factor;'' and the ``default FQPA safety factor.'' By the term 
``traditional uncertainty factor,'' EPA is referring to those 
additional uncertainty factors used prior to FQPA passage to account 
for database deficiencies. These traditional uncertainty factors have 
been incorporated by the FQPA into the additional safety factor for the 
protection of infants and children. The term ``special FQPA safety 
factor'' refers to those safety factors that are deemed necessary for 
the protection of infants and children primarily as a result of the 
FQPA. The ``default FQPA safety factor'' is the additional 10X safety 
factor that is mandated by the statute unless it is decided that there 
are reliable data to choose a different additional factor (potentially 
a traditional uncertainty factor or a special FQPA safety factor).
    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 an UF of 
100 to account for interspecies and intraspecies differences and any 
traditional uncertainty factors deemed appropriate (RfD = NOAEL/UF). 
Where a special FQPA safety factor or the default FQPA safety factor is 
used, 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 safety factor.
    For non-dietary risk assessments (other than cancer) the UF is used 
to

[[Page 57203]]

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). An example of how such a probability risk is expressed 
would be to describe the risk as one in one hundred thousand (1 X 
10<SUP>-</SUP>\5\), one in a million (1 X 10<SUP>-</SUP>\6\), or one in 
ten million (1 X 10<SUP>-</SUP>\7\). 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<INF>cancer</INF> = point of departure/exposures) is 
calculated.
    A summary of the toxicological endpoints for dimethenamid used for 
human risk assessment is shown in Table 2. of this unit:

    Table 2.--Summary of Toxicological Dose and Endpoints for Dimethenamid for Use in Human Risk Assessment.
----------------------------------------------------------------------------------------------------------------
                                          Dose Used in Risk
                                             Assessment,          Special FQPA SF and
          Exposure Scenario                Interspecies and       Level of Concern for   Study and Toxicological
                                         Intraspecies and any       Risk Assessment              Effects
                                            Traditional UF
----------------------------------------------------------------------------------------------------------------
Acute Dietary (Females 13-49 years of   NOAEL = 75 mg/kg/day    FQPA SF = 1X              Developmental Toxicity
 age) Based on [RS] data               UF = 100...............  aPAD = acute RfD / FQPA   in rabbits
                                       Acute RfD = 0.75 mg/kg/   SF = 0.75 mg/kg/day.    Maternal; LOAEL = 150
                                        day.                                              mg/kg/day based on
                                                                                          abortions and
                                                                                          decreased body weight
                                                                                          gain and food
                                                                                          consumption
                                                                                         Developmental; LOAEL =
                                                                                          150 mg/kg/day based on
                                                                                          post-implantation loss
----------------------------------------------------------------------------------------------------------------
Chronic Dietary (All populations)      NOAEL= 5 mg/kg/day       FQPA SF = 1X             Chronic/rats
 Based on [RS] data                    UF = 100...............  cPAD = chronic RfD /     LOAEL = M/F; 36/49 mg/
                                       Chronic RfD = 0.05 mg/    FQPA SF = 0.05 mg/kg/    kg/day based on
                                        kg/day.                  day.                     decreased body weight
                                                                                          and body weight gain
                                                                                          in both sexes,
                                                                                          increased food
                                                                                          conversion ratios in
                                                                                          females, and increased
                                                                                          microscopic hepatic
                                                                                          lesions in both sexes
----------------------------------------------------------------------------------------------------------------
Carcinogenicity Based on [RS] data     Classified as a Group C  N/A                      Chronic risk assessment
                                        (possible human                                   protective of any
                                        carcinogen)                                       potential carcinogenic
                                                                                          risk
----------------------------------------------------------------------------------------------------------------

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. Tolerances have been 
established (40 CFR 180.464) for the residues of dimethenamid, in or on 
a variety of raw agricultural commodities. Risk assessments were 
conducted by EPA to assess dietary exposures from dimethenamid 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. In conducting the acute dietary risk assessment EPA 
used the Dietary Exposure Evaluation Model software with the Food 
Commodity Intake Database (DEEM-FCID\TM\), which incorporates food 
consumption data as reported by respondents in the United States 
Department of Agriculture (USDA) 1994-1996 and 1998 Nationwide 
Continuing Surveys of Food Intake by Individuals (CSFII), and 
accumulated exposure to the chemical for each commodity. The following 
assumptions were made for the acute exposure assessments: The residue 
estimate for each food commodity was the tolerance for that crop (0.01 
ppm) and each crop was assessed as if 100% of the crop has been treated 
with dimethenamid.
    ii. Chronic exposure. In conducting the chronic dietary risk 
assessment EPA used the DEEM-FCID\TM\, which incorporates food 
consumption data as reported by respondents in the USDA 1994-1996 and 
1998 CSFII, and accumulated exposure to the chemical for each 
commodity. The following assumptions were made for the chronic exposure 
assessments: The residue estimate for each food commodity was the 
tolerance for that crop (0.01 ppm) and each crop was assessed as if 
100% of the crop has been treated with dimethenamid.
    iii. Cancer. Dimethenamid (50:50 S:R isomers) was classified as a 
group ``C'' (possible human carcinogen). The Agency concluded that the 
chronic risk assessment, making use of the cPAD, to be protective of 
any potential carcinogenic risk. Dimethenamid is at best a weak 
carcinogen. An intermediate dose showed marginally significant results 
(p = 0.056) with liver adenomas one species (rat) and one sex (males). 
The incidence of liver tumors was just slightly increased from the 
level in the historical control data. Higher doses did not demonstrate 
the occurrence of liver adenomas significantly different from the 
controls. No dose-related tumors were seen in the mouse carcinogenicity 
study, and a battery of mutagenicity studies with dimethenamid-P (90:10 
S:R isomers) were negative or equivocal for genetic mutations including 
unscheduled DNA synthesis.
    2. Dietary exposure from drinking water. The Agency lacks 
sufficient monitoring exposure data to complete a comprehensive dietary 
exposure analysis and risk assessment for dimethenamid in drinking 
water. Because the Agency does not have comprehensive monitoring data, 
drinking water concentration estimates are made by reliance on 
simulation or modeling taking into account data on the physical 
characteristics of dimethenamid.

[[Page 57204]]

    The Agency uses the Generic Estimated Environmental Concentration 
(GENEEC) or the Pesticide Root Zone Model/Exposure Analysis Modeling 
System (PRZM/EXAMS) to estimate pesticide concentrations in surface 
water and SCI-GROW, which predicts pesticide concentrations in 
groundwater. In general, EPA will use GENEEC (a tier 1 model) before 
using PRZM/EXAMS (a tier 2 model) for a screening-level assessment for 
surface water. The GENEEC model is a subset of the PRZM/EXAMS model 
that uses a specific high-end runoff scenario for pesticides. GENEEC 
incorporates a farm pond scenario, while PRZM/EXAMS incorporate an 
index reservoir environment in place of the previous pond scenario. The 
PRZM/EXAMS model includes a percent crop area factor as an adjustment 
to account for the maximum percent crop coverage within a watershed or 
drainage basin.
    None of these models include consideration of the impact processing 
(mixing, dilution, or treatment) of raw water for distribution as 
drinking water would likely have on the removal of pesticides from the 
source water. The primary use of these models by the Agency at this 
stage is to provide a screen for sorting out pesticides for which it is 
unlikely that drinking water concentrations would exceed human health 
levels of concern.
    Since the models used are considered to be screening tools in the 
risk assessment process, the Agency does not use estimated 
environmental concentrations (EECs), which are the model estimates of a 
pesticide's concentration in water. EECs derived from these models are 
used to quantify drinking water exposure and risk as a %RfD or %PAD. 
Instead drinking water levels of comparison (DWLOCs) are calculated and 
used as a point of comparison against the model estimates of a 
pesticide's concentration in water. DWLOCs are theoretical upper limits 
on a pesticide's concentration in drinking water in light of total 
aggregate exposure to a pesticide in food, and from residential uses. 
Since DWLOCs address total aggregate exposure to dimethenamid they are 
further discussed in the aggregate risk sections in Unit III.E.
    Based on the PRZM/EXAMS and SCI-GROW models, the EECs of 
dimethenamid for acute exposures are estimated to be 49 parts per 
billion (ppb) for surface water and 0.42 ppb for groundwater. The EECs 
for chronic exposures are estimated to be 7.9 ppb (non-cancer exposure) 
and 5.1 ppb (cancer exposure) for surface water and 0.42 ppb for 
groundwater.
    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).
    Dimethenamid is not registered for use on any sites that would 
result in residential exposure.
    4. Cumulative effects from substances with a common mechanism of 
toxicity. Section 408(b)(2)(D)(v) of FFDCA requires that, when 
considering whether to establish, modify, or revoke a tolerance, the 
Agency consider ``available information'' concerning the cumulative 
effects of a particular pesticide's residues and ``other substances 
that have a common mechanism of toxicity.''
    Unlike other pesticides for which EPA has followed a cumulative 
risk approach based on a common mechanism of toxicity, EPA has not made 
a common mechanism of toxicity finding as to dimethenamid and any other 
substances. Dimethenamid 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 dimethenamid 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 policy statements released by EPA's Office of Pesticide Programs 
(OPP) concerning common mechanism determinations and procedures for 
cumulating effects from substances found to have a common mechanism on 
EPA's web site at http://www.epa.gov/pesticides/cumulative/.

D. Safety Factor for Infants and Children

    1. In general. Section 408 of FFDCA 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 based on reliable data that a different margin of 
safety will be safe for infants and children. Margins of safety are 
incorporated into EPA risk assessments either directly through use of a 
MOE analysis or through using uncertainty (safety) factors in 
calculating a dose level that poses no appreciable risk to humans. In 
applying this provision, EPA either retains the default value of 10X 
when reliable data do not support the choice of a different factor, or, 
if reliable data are available, EPA uses a different additional safety 
factor value based on the use of traditional uncertainty factors and/or 
special FQPA safety factors, as appropriate.
    2. Prenatal and postnatal sensitivity. No offspring pre- or 
postnatal susceptibility to either dimethenamid (50:50 S:R isomers) or 
dimethenamid-P (90:10 S:R isomers) was seen in a rabbit or two rat 
developmental studies and reproduction study. There is low concern for 
pre- or postnatal toxicity since the developmental effects from the [S] 
and [RS] mixture are similar and occur at similar doses.
    3. Conclusion. There is a complete toxicity data base for 
dimethenamid and exposure data are complete or are estimated based on 
data that reasonably accounts for potential exposures. EPA determined 
that the safety factor for dimethenamid should be 100 (10X safety 
factor for interspecies extrapolation and 10X for intraspecies 
variation). The additional FQPA SF was removed taking into account the 
low concerns and lack residual uncertainties with regard to prenatal 
and postnatal toxicity and the completeness of the toxicity and 
exposure data base.

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 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 EPA's Office of Water are used to calculate 
DWLOCs: 2 liter (L)/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

[[Page 57205]]

drinking water exposure assessments. Different populations will have 
different DWLOCs. Generally, a DWLOC is calculated for each type of 
risk assessment used: Acute, short-term, intermediate-term, chronic, 
and cancer.
    When EECs for surface water and ground water are less than the 
calculated DWLOCs, OPP concludes with reasonable certainty that 
exposures to the pesticide in drinking water (when considered along 
with other sources of exposure for which OPP has reliable data) would 
not result in unacceptable levels of aggregate human health risk at 
this time. Because OPP considers the aggregate risk resulting from 
multiple exposure pathways associated with a pesticide's uses, levels 
of comparison in drinking water may vary as those uses change. If new 
uses are added in the future, OPP will reassess the potential impacts 
of residues of the pesticide in drinking water as a part of the 
aggregate risk assessment process.
    1. Acute risk. The dimethenamid aPAD is 0.75 mg/kg/day (applicable 
to child bearing females only (females 13-49 years old) (Table 3.). The 
estimated acute (one day) aggregate exposure of females 13-49 years of 
age (0.006857 mg/kg/day) utilizes less than 1% of the dimethenamid 
aPAD. For the other population subgroups, an appropriate acute endpoint 
attributed to a single dose was not available in the toxicity data base 
including the developmental toxicity studies.

                     Table 3.--Aggregate Risk Assessment for Acute Exposure to Dimethenamid
----------------------------------------------------------------------------------------------------------------
                                                                             Surface       Ground
              Population Subgroup                 aPAD (mg/      % aPAD     Water EEC    Water EEC   Acute DWLOC
                                                     kg)         (Food)       (ppb)        (ppb)        (ppb)
----------------------------------------------------------------------------------------------------------------
Females 13-49 yrs                                       0.75         < 1%           49         0.42       22,294
----------------------------------------------------------------------------------------------------------------

    2. Chronic risk. The dimethenamid cPAD is 0.05 mg/kg/day. The 
estimated chronic aggregate exposure is the same as the chronic dietary 
exposure because dimethenamid has no residential uses. The chronic 
dietary exposure utilizes less than 1% of the cPAD for all population 
subgroups except infants less than 1 year old, which utilizes less than 
2% of the dimethenamid cPAD. The chronic DWLOC was acceptable for 
chronic exposure to surface and groundwater (Table 4.).

              Table 4.--Aggregate Risk Assessment for Chronic (Non-Cancer) Exposure to Dimethenamid
----------------------------------------------------------------------------------------------------------------
                                                                             Surface       Ground
              Population Subgroup                cPAD mg/kg/     % cPAD     Water EEC    Water EEC     Chronic
                                                     day         (Food)       (ppb)        (ppb)     DWLOC (ppb)
----------------------------------------------------------------------------------------------------------------
U.S. population                                         0.05          < 1          7.9         0.42        1,494
----------------------------------------------------------------------------------------------------------------
All infants (< 1 yr.)                                   0.05          < 2          7.9         0.42          494
----------------------------------------------------------------------------------------------------------------
Children 1-2 yrs.                                       0.05          < 1          7.9         0.42          497
----------------------------------------------------------------------------------------------------------------
Children 3-5 yrs.                                       0.05          < 1          7.9         0.42          248
----------------------------------------------------------------------------------------------------------------
Children 6-12 yrs.                                      0.05          < 1          7.9         0.42          249
----------------------------------------------------------------------------------------------------------------
Youth 13-19 yrs.                                        0.05          < 1          7.9         0.42          249
----------------------------------------------------------------------------------------------------------------
Adults 20-49 yrs.                                       0.05          < 1          7.9         0.42        1,494
----------------------------------------------------------------------------------------------------------------
Adults 50+ yrs.                                        0.024          < 1          7.9         0.42          719
----------------------------------------------------------------------------------------------------------------
Females 13-49 yrs.                                     0.024          < 1          7.9         0.42          719
----------------------------------------------------------------------------------------------------------------

    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).
    Dimethenamid 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).
    Dimethenamid 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 considers 
the chronic aggregate risk assessment, making use of the cPAD, to be 
protective of any aggregate cancer risk. See Table 4., Unit III.E.2.
    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 dimethenamid residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    Adequate enforcement methodology (AM-0884-0193-1) is available to 
enforce the tolerance expression. AM-0884-0193-1 is a GC method using 
an HP-1 or HP-5 column and mass selective detection (MSD). The method 
may be requested from: Chief, Analytical Chemistry Branch, 
Environmental Science Center, 701 Mapes Rd., Ft. Meade, MD 20755-5350; 
telephone number: (410) 305-2905; e-mail address: 
<a href="/cdn-cgi/l/email-protection#40322533292435252d2534282f2433002530216e272f36"><span class="__cf_email__" data-cfemail="532136203a3726363e36273b3c3720133623327d343c25">[email protected]</span></a>.

[[Page 57206]]

B. International Residue Limits

    There are no Codex maximum residue levels (MRL's) for dimethenamid.

C. Conditions

    There are no conditions of registration for establishment of 
tolerances on: onions (dry bulb), garlic, shallots (dry bulb), tuberous 
and corm vegetables, sugar beets, garden beets, and horseradish.

V. Conclusion

    Therefore, the tolerance is established for residues of 
dimethenamid, (R,S)-2-chloro-N-[(1-methyl-2-methoxy) ethyl]-N-(2,4-
dimethyl-thien-3-yl)-acetamide, in or on onions (dry bulb), garlic, 
shallots (dry bulb), tuberous and corm vegetables, sugar beets, garden 
beets, and horseradish at 0.01 ppm. This action results in the 
reassessment of thirteen tolerances as follows: bean, dry, seed at 0.01 
ppm; corn, forage at 0.01 ppm; corn, grain at 0.01 ppm; corn, stover at 
0.01 ppm; corn, sweet, fodder (stover) at 0.01 ppm; corn, sweet, forage 
at 0.01 ppm; corn, sweet, kernel plus cob with husks removed at 0.01 
ppm; peanut at 0.01 ppm; peanut, hay at 0.01 ppm; sorghum, grain, 
fodder at 0.01 ppm; sorghum, grain, forage at 0.01 ppm; sorghum, grain 
at 0.01 ppm; and soybeans at 0.01 ppm.

VI. Objections and Hearing Requests

    Under section 408(g) of FFDCA, as amended by FQPA, any person may 
file an objection to any aspect of this regulation and may also request 
a hearing on those objections. The EPA procedural regulations which 
govern the submission of objections and requests for hearings appear in 
40 CFR part 178. Although the procedures in those regulations require 
some modification to reflect the amendments made to FFDCA by FQPA, EPA 
will continue to use those procedures, with appropriate adjustments, 
until the necessary modifications can be made. The new section 408(g) 
of FFDCA 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) of FFDCA, as was 
provided in the old sections 408 and 409 of FFDCA. However, the period 
for filing objections is now 60 days, rather than 30 days.

A. What Do I Need to Do to File an Objection or Request a Hearing?

    You must file your objection or request a hearing on this 
regulation in accordance with the instructions provided in this unit 
and in 40 CFR part 178. To ensure proper receipt by EPA, you must 
identify docket ID number OPP-2004-0315 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 
23, 2004.
    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 (1900L), 
Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460-0001. You may also deliver your request to the 
Office of the Hearing Clerk in Suite 350, 1099 14\th\ St., NW., 
Washington, DC 20005. 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) 564-6255.
    2. 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 ADDRESSES. Mail your 
copies, identified by docket ID number OPP-2004-0315, 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-
0001. In person or by courier, bring a copy to the location of the 
PIRIB described in ADDRESSES. You may also send an electronic copy of 
your request via e-mail to: <a href="/cdn-cgi/l/email-protection#aac5dada87cec5c9c1cfdeeacfdacb84cdc5dc"><span class="__cf_email__" data-cfemail="a1ced1d18cc5cec2cac4d5e1c4d1c08fc6ced7">[email protected]</span></a>. Please use an ASCII 
file format and avoid the use of special characters and any form of 
encryption. Copies of electronic objections and hearing requests will 
also be accepted on disks in WordPerfect 6.1/8.0 or ASCII file format. 
Do not include any CBI in your electronic copy. You may also submit an 
electronic copy of your request at many Federal Depository Libraries.

B. When Will the Agency Grant a Request for a Hearing?

    A request for a hearing will be granted if the Administrator 
determines that the material submitted shows the following: There is a 
genuine and substantial issue of fact; there is a reasonable 
possibility that available evidence identified by the requestor would, 
if established resolve one or more of such issues in favor of the 
requestor, taking into account uncontested claims or facts to the 
contrary; and resolution of the factual issues(s) in the manner sought 
by the requestor would be adequate to justify the action requested (40 
CFR 178.32).

VII. Statutory and Executive Order Reviews

    This final rule establishes a tolerance under section 408(d) of 
FFDCA in response to a petition submitted to the Agency. The Office of 
Management and Budget (OMB) has exempted these types of actions from 
review under Executive Order 12866, entitled Regulatory Planning and 
Review (58 FR 51735, October 4, 1993). Because this rule has been 
exempted from review under Executive Order 12866 due to its lack of 
significance, this rule is not subject to Executive Order 13211, 
Actions Concerning Regulations That Significantly Affect Energy Supply, 
Distribution, or Use (66 FR 28355, May 22, 2001). This final rule does 
not contain any information collections subject to OMB approval under 
the Paperwork Reduction Act (PRA), 44 U.S.C. 3501 et seq., or impose 
any enforceable duty or contain any unfunded mandate as described under 
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA) (Public Law 
104-4). Nor does it require any special considerations under Executive 
Order 12898, entitled Federal Actions to Address Environmental Justice 
in Minority Populations and Low-Income Populations (59 FR 7629, 
February 16, 1994); or OMB review or any Agency action under Executive 
Order 13045, entitled Protection of Children from Environmental Health 
Risks and Safety Risks (62 FR 19885, April 23, 1997). This action does 
not involve any technical standards that would require Agency 
consideration of voluntary consensus standards pursuant to section 
12(d) of the National Technology Transfer and Advancement Act of 1995 
(NTTAA), Public Law 104-113, section 12(d) (15 U.S.C. 272 note). Since 
tolerances and exemptions that are established on the basis of a 
petition

[[Page 57207]]

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

VIII. Congressional Review Act

    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 14, 2004.
Lois Rossi,
Director, Registration Division, Office of Pesticide Programs.

    Therefore, 40 CFR part 180 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 180.464 is amended as follows:
    a. By revising paragraph (a).
    b. By removing and reserving paragraph (b).


Sec.  180.464  Dimethenamid, 2-chloro-N-[(1-methyl-2-methoxy)ethyl]-N-
(2,4-dimethylthien-3-yl)-acetamide.

    (a) General. Tolerances are established for residues of the 
herbicide dimethenamid, 1(R,S)-2-chloro-N-[(1-methyl-2-methoxy)ethyl]-
N-(2,4-dimethylthien-3-yl)-acetamide, applied as either the 90:10 or 
50:50 S:R isomers, in or on the following food commodities:

------------------------------------------------------------------------
                                                              Parts per
                         Commodity                             million
------------------------------------------------------------------------
Bean, dry, seed............................................         0.01
Beet, garden, roots........................................         0.01
Beet, garden, tops.........................................         0.01
Beet, sugar, dried pulp....................................         0.01
Beet, sugar, molasses......................................         0.01
Beet, sugar, roots.........................................         0.01
Beet, sugar, tops..........................................         0.01
Corn, field, forage........................................         0.01
Corn, field, grain.........................................         0.01
Corn, field, stover........................................         0.01
Corn, pop, forage..........................................         0.01
Corn, pop, grain...........................................         0.01
Corn, pop, stover..........................................         0.01
Corn, sweet, forage........................................         0.01
Corn, sweet, kernal plus cob with husks removed............         0.01
Corn, sweet, stover........................................         0.01
Garlic.....................................................         0.01
Onion, dry bulb............................................         0.01
Peanut, hay................................................         0.01
Peanut, nutmeat............................................         0.01
Shallot, bulb..............................................         0.01
Sorghum, grain.............................................         0.01
Sorghum, grain, forage.....................................         0.01
Sorghum, grain, stover.....................................         0.01
Soybean, seed..............................................         0.01
Tuberous and corm vegetables...............................         0.01
------------------------------------------------------------------------

    (b) Section 18 emergency exemptions. [Reserved]

[FR Doc. 04-21501 Filed 9-23-04; 8:45 am]
BILLING CODE 6560-50-S


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