98-33121. Tralkoxydim; Time-Limited Pesticide Tolerances  

  • [Federal Register Volume 63, Number 241 (Wednesday, December 16, 1998)]
    [Rules and Regulations]
    [Pages 69194-69200]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 98-33121]
    
    
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    ENVIRONMENTAL PROTECTION AGENCY
    
    40 CFR Part 180
    
    [OPP-300764; FRL-6048-4]
    RIN 2070-AB78
    
    
    Tralkoxydim; Time-Limited Pesticide Tolerances
    
    AGENCY: Environmental Protection Agency (EPA).
    
    ACTION: Final rule.
    
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    SUMMARY: This regulation establishes time-limited tolerances for 
    residues of the herbicide tralkoxydim in or on certain raw agricultural 
    commodities. Zeneca Ag Products requested this tolerance under the 
    Federal Food, Drug and Cosmetic Act (FFDCA), as amended by the Food 
    Quality Protection Act of 1996 (Pub. L. 104-170). These tolerances will 
    expire on February 28, 2003.
    
    DATES: This regulation is effective December 16, 1998. Objections and 
    requests for hearings must be received by EPA on or before February 16, 
    1999.
    
    ADDRESSES: Written objections and hearing requests, identified by the 
    docket control number, [OPP-300764], must be submitted to: Hearing 
    Clerk (1900), Environmental Protection Agency, Rm. M3708, 401 M St., 
    SW., Washington, DC 20460. Fees accompanying objections and hearing 
    requests shall be labeled ``Tolerance Petition Fees'' and forwarded to: 
    EPA Headquarters Accounting Operations Branch, OPP (Tolerance Fees), 
    P.O. Box 360277M, Pittsburgh, PA 15251. A copy of any objections and 
    hearing requests filed with the Hearing Clerk identified by the docket 
    control number, [OPP-300764], must also be submitted to: Public 
    Information and Records Integrity Branch, Information Resources and 
    Services Division (7502C), Office of Pesticide Programs, Environmental 
    Protection Agency, 401 M St., SW., Washington, DC 20460. In person, 
    bring a copy of objections and hearing requests to Rm. 119, Crystal 
    Mall 2 (CM #2), 1921 Jefferson Davis Hwy., Arlington, VA.
        A copy of objections and hearing requests filed with the Hearing 
    Clerk may also be submitted electronically by sending electronic mail 
    (e-mail) to: opp-docket@epamail.epa.gov. Copies of objections and 
    hearing requests must be submitted as an ASCII file avoiding the use of 
    special characters and any form of encryption. Copies of objections and 
    hearing requests will also be accepted on disks in WordPerfect 5.1/6.1 
    file format or ASCII file format. All copies of objections and hearing 
    requests in electronic form must be identified by the docket control 
    number [OPP-300764]. No Confidential Business Information (CBI) should 
    be submitted through e-mail. Electronic copies of objections and 
    hearing requests on this rule may be filed online at many Federal 
    Depository Libraries.
    
    FOR FURTHER INFORMATION CONTACT: By mail: James A. Tompkins, 
    Registration Division 7505C, Office of Pesticide Programs, 
    Environmental Protection Agency, 401 M St., S.W., Washington, DC 20460. 
    Office location, telephone number, and e-mail address: Rm. 239, CM #2, 
    1921 Jefferson Davis Hwy., Arlington, VA, (703) 305-5697, e-mail: 
    tompkins.jim@epamail.epa.gov.
    
    SUPPLEMENTARY INFORMATION: In the Federal Register of July 2, 1997 (62 
    FR 35804)(FRL-5722-9), EPA, issued a notice pursuant to section 408 of 
    the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a 
    announcing the filing of a pesticide petition (PP 6F4631) for tolerance 
    by Zeneca Ag Products, 1800 Concord Pike, P.O. Box 15458, Wilmington, 
    DE 19850-5458. This notice included a summary of the petition prepared 
    by Zeneca Ag Products, the registrant. There were no comments received 
    in response to the notice of filing.
        The petition requested that 40 CFR part 180 be amended by 
    establishing time-limited tolerances for residues of the herbicide, 
    tralkoxydim, 2-(Cyclohexen-1-one, 2-[1-(ethoxyimino)propyl]-3-hydroxy-
    5-(2,4,6-trimethylphenyl)-(9Cl), in or on the raw agricultural 
    commodities barley grain, barley straw, barley hay, wheat grain, wheat 
    forage, wheat straw, and wheat hay at 0.1 parts per million (ppm). 
    Zeneca Ag Products subsequently amended the proposed tolerances to 
    lower the residue levels, as follows; barley grain, barley hay, wheat 
    grain and wheat hay at 0.02 ppm, and barley straw, wheat forage and 
    wheat straw at 0.05 ppm. These tolerances will expire on February 28, 
    2003.
    
    I. Risk Assessment and Statutory Findings
    
        Section 408(b)(2)(A)(i) of the FFDCA allows EPA to establish a 
    tolerance (the legal limit for a pesticide chemical residue in or on a 
    food) only if EPA determines that the tolerance is ``safe.'' Section 
    408(b)(2)(A)(ii) defines ``safe'' to mean that ``there is a reasonable 
    certainty that no harm will result from aggregate exposure to the 
    pesticide chemical residue, including all anticipated dietary exposures 
    and all other exposures for which there is reliable information.'' This 
    includes exposure through drinking water and in residential settings, 
    but does not include occupational exposure. Section 408(b)(2)(C) 
    requires EPA to give special consideration to exposure of infants and 
    children to the pesticide chemical residue in establishing a tolerance 
    and to ``ensure that there is a reasonable certainty that no harm will 
    result to infants and children from aggregate exposure to the pesticide 
    chemical residue. . . .''
        EPA performs a number of analyses to determine the risks from 
    aggregate exposure to pesticide residues. For further discussion of the 
    regulatory requirements of section 408 and a complete description of 
    the risk assessment process, see the Final Rule on Bifenthrin Pesticide 
    Tolerances (62 FR 62961, November 26, 1997) (FRL-5754-7).
    
    A. Toxicity
    
        1. Threshold and non-threshold effects. For many animal studies, a 
    dose response relationship can be determined, which provides a dose 
    that causes adverse effects (threshold effects) and doses causing no 
    observed effects (the ``no-observed adverse effect level'' or 
    ``NOAEL'').
        Once a study has been evaluated and the observed effects have been 
    determined to be threshold effects, EPA generally divides the NOAEL 
    from the study with the lowest NOAEL by an uncertainty factor (usually 
    100 or more) to determine the Reference Dose (RfD). The RfD is a level 
    at or below which daily aggregate exposure over a lifetime will not 
    pose appreciable risks to human health. An uncertainty factor 
    (sometimes called a ``safety factor'') of 100 is commonly used since it 
    is assumed that people may be up to 10 times more sensitive to 
    pesticides than the test animals, and that one person or subgroup of 
    the population (such as infants and children) could be up to 10 times 
    more sensitive to a pesticide than another. In addition, EPA assesses 
    the potential risks to infants and children based on the weight of the 
    evidence of the toxicology studies and determines whether an additional 
    uncertainty factor is warranted. Thus, an aggregate daily exposure to a 
    pesticide residue at or below the Rfd (expressed as 100% or less of the 
    RfD) is generally considered acceptable by EPA. EPA generally uses
    
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    the RfD to evaluate the chronic risks posed by pesticide exposure. For 
    shorter term risks, EPA calculates a margin of exposure (MOE) by 
    dividing the estimated human exposure into the NOAEL from the 
    appropriate animal study. Commonly, EPA finds MOEs lower than 100 to be 
    unacceptable. This 100-fold MOE is based on the same rationale as the 
    100-fold uncertainty factor.
        Lifetime feeding studies in two species of laboratory animals are 
    conducted to screen pesticides for cancer effects. When evidence of 
    increased cancer is noted in these studies, the Agency conducts a 
    weight of the evidence review of all relevant toxicological data 
    including short-term and mutagenicity studies and structure activity 
    relationship. Once a pesticide has been classified as a potential human 
    carcinogen, different types of risk assessments (e.g., linear low dose 
    extrapolations or MOE calculation based on the appropriate NOAEL) will 
    be carried out based on the nature of the carcinogenic response and the 
    Agency's knowledge of its mode of action.
        2. Differences in toxic effect due to exposure duration. The 
    toxicological effects of a pesticide can vary with different exposure 
    durations. EPA considers the entire toxicity data base, and based on 
    the effects seen for different durations and routes of exposure, 
    determines which risk assessments should be done to assure that the 
    public is adequately protected from any pesticide exposure scenario. 
    Both short and long durations of exposure are always considered. 
    Typically, risk assessments include ``acute'', ``short-term'', 
    ``intermediate term'', and ``chronic'' risks. These assessments are 
    defined by the Agency as follows.
        Acute risk, by the Agency's definition, results from 1-day 
    consumption of food and water, and reflects toxicity which could be 
    expressed following a single oral exposure to the pesticide residues. 
    High end exposure to food and water residues are typically assumed.
        Short-term risk results from exposure to the pesticide for a period 
    of 1-7 days, and therefore overlaps with the acute risk assessment. 
    Historically, this risk assessment was intended to address primarily 
    dermal and inhalation exposure which could result, for example, from 
    residential pesticide applications. However, since enaction of FQPA, 
    this assessment has been expanded to include both dietary and non-
    dietary sources of exposure, and will typically consider exposure from 
    food, water, and residential uses when reliable data are available. In 
    this assessment, risks from average food and water exposure, and high-
    end residential exposure, are aggregated. High-end exposures from all 
    three sources are not typically added because of the very low 
    probability of this occurring in most cases, and because the other 
    conservative assumptions built into the assessment assure adequate 
    protection of public health. However, for cases in which high-end 
    exposure can reasonably be expected from multiple sources (e.g. 
    frequent and widespread homeowner use in a specific geographical area), 
    multiple high-end risks will be aggregated and presented as part of the 
    comprehensive risk assessment/characterization. Since the toxicological 
    endpoint considered in this assessment reflects exposure over a period 
    of at least 7 days, an additional degree of conservatism is built into 
    the assessment; i.e., the risk assessment nominally covers 1-7 days 
    exposure, and the toxicological endpoint/NOAEL is selected to be 
    adequate for at least 7 days of exposure. (Toxicity results at lower 
    levels when the dosing duration is increased.)
        Intermediate-term risk results from exposure for 7 days to several 
    months. This assessment is handled in a manner similar to the short-
    term risk assessment.
        Chronic risk assessment describes risk which could result from 
    several months to a lifetime of exposure. For this assessment, risks 
    are aggregated considering average exposure from all sources for 
    representative population subgroups including infants and children.
    
    B. Aggregate Exposure
    
        In examining aggregate exposure, FFDCA section 408 requires that 
    EPA take into account available and reliable information concerning 
    exposure from the pesticide residue in the food in question, residues 
    in other foods for which there are tolerances, residues in groundwater 
    or surface water that is consumed as drinking water, and other non-
    occupational exposures through pesticide use in gardens, lawns, or 
    buildings (residential and other indoor uses). Dietary exposure to 
    residues of a pesticide in a food commodity are estimated by 
    multiplying the average daily consumption of the food forms of that 
    commodity by the tolerance level or the anticipated pesticide residue 
    level. The Theoretical Maximum Residue Contribution (TMRC) is an 
    estimate of the level of residues consumed daily if each food item 
    contained pesticide residues equal to the tolerance. In evaluating food 
    exposures, EPA takes into account varying consumption patterns of major 
    identifiable subgroups of consumers, including infants and children. 
    The TMRC is a ``worst case'' estimate since it is based on the 
    assumptions that food contains pesticide residues at the tolerance 
    level and that 100% of the crop is treated by pesticides that have 
    established tolerances. If the TMRC exceeds the RfD or poses a lifetime 
    cancer risk that is greater than approximately one in a million, EPA 
    attempts to derive a more accurate exposure estimate for the pesticide 
    by evaluating additional types of information (anticipated residue data 
    and/or percent of crop treated data) which show, generally, that 
    pesticide residues in most foods when they are eaten are well below 
    established tolerances.
        Percent of crop treated estimates are derived from federal and 
    private market survey data. Typically, a range of estimates are 
    supplied and the upper end of this range is assumed for the exposure 
    assessment. By using this upper end estimate of percent of crop 
    treated, the Agency is reasonably certain that exposure is not 
    understated for any significant subpopulation group. Further, regional 
    consumption information is taken into account through EPA's computer-
    based model for evaluating the exposure of significant subpopulations 
    including several regional groups, to pesticide residues. For this 
    pesticide, the most highly exposed population subgroup children 1-6 
    years was not regionally based.
    
    II. 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 
    tralkoxydim and to make a determination on aggregate exposure, 
    consistent with section 408(b)(2), for a time-limited tolerance for 
    residues of tralkoxydim in certain raw agricultural commodities. EPA's 
    assessment of the dietary 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
    
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    toxic effects caused by tralkoxydim are discussed below.
        1. A rat acute oral study with a LD50 of 1,258 
    milligrams (mg)/kilogram (kg) for males and 934 mg/kg for females.
        2. A mouse acute oral study with a LD50 of 1,231 mg/kg 
    for males and 1,100 mg/kg for females.
        3. A 90-day rat feeding study with a NOAEL of 250 ppm [20.5 mg/kg/
    day] and a Lowest Observed Adverse Effect Level (LOAEL) of 2,500 ppm 
    [204.8 mg/kg/day] based on decreased food efficacy and minor 
    hematologic changes.
        4. A 90-day dog dietary study with a NOAEL of 0.5 mg/kg/day and a 
    LOAEL of 5 mg/kg/day based on increased liver weights in males and 
    increases in APDM in males and females, indicating minimal 
    hepatotoxicity.
        5. A 90-day hamster feeding study with a NOAEL of 5,000 ppm [328 
    mg/kg/day] and a LOAEL of 10,000 ppm [650 mg/kg/day] based on decreased 
    body weight gains and increased liver weights in both sexes.
        6. A 21-day rat dermal study with a NOAEL of 1,000 mg/kg/day, the 
    highest dose tested [HDT].
        7. A 1-year dog chronic feeding study with a NOAEL of 0.5 mg/kg/day 
    and a LOAEL of 5 mg/kg/day based on changes in liver function and 
    morphology in males.
        8. A rat chronic feeding / carcinogenicity study with a NOAEL for 
    systemic toxicity of 500 ppm [23.1 mg/kg/day in males and 30.1 mg/kg/
    day in females] and a LOAEL for systemic toxicity of 2,500 ppm [117.9 
    mg/kg/day in males and 162.8 mg/kg/day in females] based on decreased 
    body weight gain, decreased food consumption, increased liver weights, 
    and increased hepatic clear cell areas and increased ALT levels in 
    females. Based on the incidence of Leydig cell tumors of the testes in 
    males, tralkoxydim was considered to have a positive carcinogenic 
    response.
        9. A 3-generation rat reproduction study with a parental systemic 
    NOAEL of 200 ppm [20 mg/kg/day] and a systemic LOAEL of 1,000 ppm [100 
    mg/kg/day] based on reduced body weights and body weight gains in 
    females. No reproductive toxicity was observed. The developmental NOAEL 
    of 200 ppm and a LOAEL of 1,000 ppm based on decreased mean pup weights 
    (F1a and F3a) and pup weight gains 
    (F2a) .
        10. A rat developmental study with a maternal NOAEL of 30 mg/kg/day 
    and with a maternal LOAEL of 200 mg/kg/day based on maternal mortality, 
    reduced body weights, and reduced food consumption and a developmental 
    NOAEL of 30 mg/kg/day and a developmental LOAEL of 200 mg/kg/day based 
    on reduced ossification of the centrum and hemicentrum, centrum 
    bipartite, misshapen centra and fused centra.
        11. A rabbit developmental study with a maternal NOAEL of 20 mg/kg/
    day and a maternal LOAEL of 100 mg/kg/day based on reduced food 
    consumption and a developmental NOAEL of 20 mg/kg/day and a 
    developmental LOAEL of 100 mg/kg/day based on abortions and increases 
    in late resorptions.
        12. Tralkoxydim was negative for mutagenic/genotoxic effects in a 
    Gene mutation Ames Assay in bacteria, a forward gene mutation in mouse 
    lymphoma cells in culture, chromosome damage/In vitro assay in human 
    lymphocyte cells, DNA damage repair in vivo assay in rat hepatocytes, 
    and chromosome damage in vivo mouse micronuclei.
        13. Based on the results of the hamster and rat metabolism studies, 
    tralkoxydim was readily absorbed and excreted within 24 and 48 hours 
    after dosing, respectively. In hamsters, the metabolic profile in urine 
    was similar for males and females; no unchanged tralkoxydim was 
    detected and two major metabolites were identified: tralkoxydim acid 
    and tralkoxydim acid oxazole. The metabolic profile in the urine of 
    rats included two additional metabolites, tralkoxydim alcohol and 
    tralkoxydim diol.
        14. Several mechanistic studies and subchronic feeding studies were 
    submitted to support the selection of hamster in preference to the 
    mouse in assessing the carcinogenic potential of tralkoxydim. The 
    submitted data indicate that of all the species tested only the mouse 
    is susceptible to porphydrin accumulation in the liver following 
    treatment with tralkoxydim. The mouse was considered an inappropriate 
    species to use for carcinogenicity testing of tralkoxydim because of 
    its distinctive method of metabolism. However, the submitted hamster 
    cancer study was unacceptable owing to unacceptably high mortality in 
    the females. An acceptable second species carcinogenicity study is 
    required.
    
    B. Toxicological Endpoints
    
        1. Acute dietary toxicity. EPA has established an acute RfD for 
    tralkoxydim of 0.3 milligrams/kilogram/day (mg/kg/day). This RfD is 
    based on the NOAEL of 30 mg/kg/day established in the rat developmental 
    study and using an uncertainty factor of 100 based on 10 X for inter-
    species extrapolation and 10X for intra-species variation.
        2. Short - and intermediate - term toxicity. EPA could not identify 
    any toxicological effects that could be attributable to short or 
    intermediate-term dietary exposure .
        3. Chronic toxicity. EPA has established the RfD for tralkoxydim at 
    0.005 mg/kg/day. This RfD is based on NOAEL of 0.5 mg/kg/day in the 
    chronic toxicity study in dogs with a 100-fold uncertainty factor to 
    account for inter-species extrapolation (10 x) and intra-species 
    variability (10 x).
        4. Carcinogenicity. The Health Effects Division Cancer Assessment 
    Review Committee has classified Tralkoxydim in accordance with the 
    Agency's Proposed Guidelines for Carcinogen Risk Assessment (April 10, 
    1996) as a ``likely to be human carcinogen''. This classification is 
    based on the following factors:
        i. Occurrence of benign Leydig cell tumors at all dose levels with 
    the incidences at the high dose exceeding the concurrent and historical 
    control range.
        ii. Lack of an acceptable carcinogenicity study in a second species 
    as required by Subdivision F Guidelines.
        iii. The relevance of the testicular tumors to human exposure can 
    not be discounted
    
    C. Exposures and Risks
    
        1. From food and feed uses.  The proposed tolerances in or on the 
    raw agricultural commodities: barley grain, barley hay, wheat grain and 
    wheat hay at 0.02 ppm, and barley straw, wheat forage and wheat straw 
    at 0.05 ppm are the first to be established for tralkoxydim, 2-
    (Cyclohexen-1-one, 2-[1-(ethoxyimino)propyl]-3-hydroxy-5-(2,4,6-
    trimethylphenyl)-(9Cl). There is no reasonable expectation of residues 
    of tralkoxydim occurring in meat, milk, poultry, or eggs from its use 
    on wheat and barley. Risk assessments were conducted by EPA to assess 
    dietary exposures from tralkoxydim as follows:
        i. Acute exposure and risk. 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. An acute dietary risk assessment was 
    conducted for tralkoxydim based on the NOAEL of 30 mg/kg/day from the 
    rat developmental study. The acute dietary analysis using the DEEM 
    computer program estimates that the distribution of single-day 
    exposures utilizes 0.02% of acute RfD.
        ii. Chronic exposure and risk. The Reference Dose (RfD) for 
    Tralkoxydim is 0.005 mg/kg/day. This value is based on
    
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    the systemic NOAEL of 0.5 mg/kg/day in the dog chronic feeding study 
    with a 100-fold safety factor to account for interspecies extrapolation 
    (10x) and intraspecies variability (10x).
        A DEEM chronic exposure analysis was conducted using tolerance 
    levels for wheat and barley and assuming that 100% of the crop is 
    treated to estimate dietary exposure for the general population and 22 
    subgroups. The chronic analysis showed that exposures from the 
    tolerance level residues in or on wheat, and barley for children 1-6 
    years old (the subgroup with the highest exposure) would be 1.4% of the 
    Reference Dose (RfD). The exposure for the general U.S. population 
    would be less than 1% of the RfD.
        iii. A lifetime dietary carcinogenicity exposure analysis was 
    conducted for tralkoxydim using the proposed tolerances along with the 
    assumption of 100% of the crop treated and a Q* of 1.68 x 10-
    2 (mg/kg/day)-1. A lifetime risk exposure 
    analysis was also conducted using the DEEM computer analysis. The 
    estimated cancer risk (5 x 10-7) is less than the level that 
    the Agency usually considers for negligible cancer risk estimates.
        2. From drinking water. Drinking water estimated concentrations 
    (DWECs) for surface water (parent tralkoxydim) were calculated by PRIZM 
    computer models to be an average of 9.1 parts per billion (ppb). the 
    DWECs for ground water based on the computer model SCI-GROW2 were 
    calculated to be an average of .016 ppb.
        3.  From non-dietary exposure. There are no non-food uses of 
    tralkoxydim currently registered under the Federal Insecticide, 
    Fungicide and Rodenticide Act, as amended. No non-dietary exposures are 
    expected for the general population.
        4. Cumulative exposure to substances with common mechanism of 
    toxicity. Section 408(b)(2)(D)(v) requires that, when considering 
    whether to establish, modify, or revoke a tolerance, the Agency 
    consider ``available information'' concerning the cumulative effects of 
    a particular pesticide's residues and ``other substances that have a 
    common mechanism of toxicity.''
        EPA does not have, at this time, available data to determine 
    whether tralkoxydim has a common mechanism of toxicity with other 
    substances or how to include this pesticide in a cumulative risk 
    assessment. Tralkoxydim is structurally a cyclohexanedione. Unlike 
    other pesticides for which EPA has followed a cumulative risk approach 
    based on a common mechanism of toxicity, tralkoxydim does not appear to 
    produce a toxic metabolite produced by other substances. For the 
    purposes of these tolerances action, therefore, EPA has not assumed 
    that tralkoxydim 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. Aggregate Risks and Determination of Safety for U.S. Population
    
        1. Acute risk. The acute dietary analysis based on the NOAEL of 30 
    mg/kg/day from the rat developmental study using the DEEM computer 
    program estimates that the distribution of single-day exposures 
    utilizes 0.02% of acute RfD. The drinking water level of comparisons 
    (DWLOCs) for acute exposure to tralkoxydim in drinking water calculated 
    for females 13+ years old was 9,000 ppb. The estimated average 
    concentration in surface water for tralkoxydim is 9 ppb. EPA's acute 
    drinking water level of comparison is well above the estimated 
    exposures for tralkoxydim in water for the subgroup of concern. For 
    groundwater, the estimated environmental concentrations (EEC's) using 
    the SCI-GROW model were all less than 1 ppb.
        2. Chronic risk. A DEEM chronic exposure analysis showed that 
    exposure from tolerance level residues in or on wheat, and barley for 
    children 1-6 years old (the subgroup with the highest exposure) would 
    be 1.4% of the Reference Dose (RfD). The exposure for the general U.S. 
    population would be less than 1% of the RfD. The drinking water level 
    of comparisons (DWLOCs) for chronic exposure to tralkoxydim in drinking 
    water calculated for U.S. population was 150 ppb and for children (1-6 
    years old) the DWLOC was 50 ppb. The estimated average concentration in 
    surface water for tralkoxydim is 9 ppb. EPA's chronic drinking water 
    level of concern is above the estimated exposures for tralkoxydim in 
    water for the U.S. population and the subgroup of concern. Conservative 
    model estimates (SCI-GROW) of the concentrations of tralkoxydim in 
    groundwater indicate that exposure will be minimal.
        3. Cancer risk. A DWLOC for cancer was calculated as 1 ppb. The 
    estimated concentration in surface water and groundwater for 
    tralkoxydim for chronic exposure are 0.9 ppb [2.8 ppb (the 56-day 
    concentration)/3] and 0.1 ppb, respectively. The model exposure 
    estimates are less than the cancer DWLOC.
        EPA concludes that there is a reasonable certainty that no harm 
    will result from aggregate exposure to tralkoxydim residues.
    
    E. Aggregate Risks and Determination of Safety for Infants and Children
    
        Safety factor for infants and children. In assessing the potential 
    for additional sensitivity of infants and children to residues of 
    tralkoxydim, EPA considered data from developmental toxicity studies in 
    the rat and rabbit and a 2-generation reproduction study in the rat. 
    The developmental toxicity studies are designed to evaluate adverse 
    effects on the developing organism resulting from maternal pesticide 
    exposure gestation. Reproduction studies provide information relating 
    to effects from exposure to the pesticide on the reproductive 
    capability of mating animals and data on systemic toxicity.
        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 pre- and post-natal toxicity and the 
    completeness of the database unless EPA determines that a different 
    margin of safety will be safe for infants and children. The Agency 
    concluded that an extra safety factor to protect infants and children 
    is not needed based on the following considerations:
        \ The toxicology data base is complete for the assessment of 
    special sensitivity of infants and children
        \ The developmental and reproductive toxicity data do not indicate 
    increase susceptibility of rats or rabbits to in utero and/or postnatal 
    exposure
        \ The NOAEL used in deriving the RfD is based on changes in liver 
    function and morphology in male adult dogs (not developmental or 
    neurotoxic effects) after chronic exposure and thus are not relevant 
    for enhanced sensitivity to infants and children
        \ Unrefined dietary exposure estimates (assuming all commodities 
    contain tolerance level residues) overestimate dietary exposure
        \ Model data used for ground and surface source drinking water 
    exposure assessments result in estimates considered to be upper-bound 
    concentrations
        \ There are no registered uses for tralkoxydim that could result in 
    residential exposures.
        EPA concludes that there is a reasonable certainty that no harm 
    will result to children from aggregate exposure to tralkoxydim 
    residues.
    
    [[Page 69198]]
    
    III. Other Considerations
    
    A. Metabolism In Plants and Animals
    
        The nature of the residue in barley, wheat, rotational crops, and 
    livestock is adequately understood. The residues of concern for the 
    tolerance expression are parent per se. Based on the results of animal 
    metabolism studies it is unlikely that secondary residues would occur 
    in animal commodities from the use of tralkoxydim on wheat and barley.
    
    B. Analytical Enforcement Methodology
    
        An adequate analytical method, gas chromatography/mass spectrometry 
    with selected ion monitoring, is available for enforcement purposes. 
    Because of the long lead time from establishing these tolerances to 
    publication of the enforcement methodology in the Pesticide Analytical 
    Manual, Vol. II, the analytical methodology is being made available in 
    the interim to anyone interested in pesticide enforcement when 
    requested from: Calvin Furlow, PRRIB, IRSD (7502C), Office of Pesticide 
    Programs, Environmental Protection Agency, 401 M St., SW., Washington, 
    DC 20460. Office location and telephone number: Rm 101FF, CM #2, 1921 
    Jefferson Davis Hwy., Arlington, VA 22202, (703-305-5229).
    
    C. Endocrine Effects
    
        EPA is required to develop a screening program to determine whether 
    certain substances (including all pesticides and inerts) ``may have an 
    effect in humans that is similar to an effect produced by a naturally 
    occurring estrogen, or such other effect . . . '' The Agency is 
    currently working with interested stakeholders, including other 
    government agencies, public interest groups, industry and research 
    scientists in developing a screening and testing program and a priority 
    setting scheme to implement this program. Congress has allowed 3 years 
    from the passage of FQPA (August 3, 1999) to implement this program. At 
    that time, EPA may require further testing of this active ingredient 
    and end use products for endocrine disrupter effects.
    
    D. Magnitude of Residues
    
        Based on the results of animal metabolism studies it is unlikely 
    that significant residues would occur in secondary animal commodities 
    from the use of tralkoxydim on wheat and barley.
        The nature of the residue in plants is adequately understood for 
    the purposes of these time-limited tolerances.
    
    E. International Residue Limits
    
        There are no Codex Alimentarius Commission (Codex) or Mexican 
    Maximum Residue Levels (MRLs) for tralkoxydim at this time.
    
    F. Rotational Crop Restrictions.
    
        No tolerances for inadvertent residues of tralkoxydim are required 
    in rotational crops.
    
    IV. Conclusion
    
        Due to the second species carcinogenicity study data gap: EPA 
    believes it is inappropriate to establish permanent tolerances for the 
    uses of tralkoxydim at this time. EPA believes that the existing data 
    support time-limited tolerances to February 28, 2003. Therefore, time-
    limited tolerances are established for residues of the herbicide, 
    tralkoxydim, 2-(Cyclohexen-1-one, 2-[1-(ethoxyimino)propyl]-3-hydroxy-
    5-(2,4,6-trimethylphenyl)-(9Cl), in or on the raw agricultural 
    commodities: barley grain, barley hay, wheat grain and wheat hay at 
    0.02 ppm, and barley straw, wheat forage and wheat straw at 0.05 ppm. 
    These time-limited tolerances will expire and be revoked on February 
    28, 2003.
    
    V. Objections and Hearing Requests
    
        The new FFDCA section 408(g) provides essentially the same process 
    for persons to ``object'' to a tolerance regulation issued by EPA under 
    new section 408(e) and (l)(6) as was provided in the old section 408 
    and in section 409. However, the period for filing objections is 60 
    days, rather than 30 days. EPA currently has procedural regulations 
    which govern the submission of objections and hearing requests. These 
    regulations will require some modification to reflect the new law. 
    However, until those modifications can be made, EPA will continue to 
    use those procedural regulations with appropriate adjustments to 
    reflect the new law.
        Any person may, by February 16, 1999, file written objections to 
    any aspect of this regulation and may also request a hearing on those 
    objections. Objections and hearing requests must be filed with the 
    Hearing Clerk, at the address given above (40 CFR 178.20). A copy of 
    the objections and/or hearing requests filed with the Hearing Clerk 
    should be submitted to the OPP docket for this rulemaking. The 
    objections submitted must specify the provisions of the regulation 
    deemed objectionable and the grounds for the objections (40 CFR 
    178.25). Each objection must be accompanied by the fee prescribed by 40 
    CFR 180.33(i) or a request for a fee waiver. If a hearing is requested, 
    the objections must include a statement of the factual issues on which 
    a hearing is requested, the requestor's contentions on such issues, and 
    a summary of any evidence relied upon by the requestor (40 CFR 178.27). 
    A request for a hearing will be granted if the Administrator determines 
    that the material submitted shows the following: There is 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 in the manner sought by the requestor 
    would be adequate to justify the action requested (40 CFR 178.32). 
    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.
    
    VI. Public Record and Electronic Submissions
    
        EPA has established a record for this rulemaking under docket 
    control number [OPP-300764] (including any comments and data submitted 
    electronically). A public version of this record, including printed, 
    paper versions of electronic comments, which does not include any 
    information claimed as CBI, is available for inspection from 8:30 a.m. 
    to 4 p.m., Monday through Friday, excluding legal holidays. The public 
    record is located in Rm. 119 of the Public Information and Records 
    Integrity Branch, Information Resources and Services Division (7502C), 
    Office of Pesticide Programs, Environmental Protection Agency, CM #2, 
    1921 Jefferson Davis Highway, Arlington, VA.
        The official record for this rulemaking, as well as the public 
    version, as described above will be kept in paper form. Accordingly, 
    EPA will transfer any copies of objections and hearing requests 
    received electronically into printed, paper form as they are received 
    and will place the paper copies in the official rulemaking record which 
    will also include all comments submitted directly in writing. The 
    official rulemaking record is the paper record maintained at the 
    Virginia
    
    [[Page 69199]]
    
    address in ``ADDRESSES'' at the beginning of this document.
    
    VII. Regulatory Assessment Requirements
    
    A. Certain Acts and Executive Orders
    
        This final rule establishes tolerances 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) (Pub. L. 104-4). Nor does 
    it require any 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 in accordance with Executive Order 
    13045, entitled Protection of Children from Environmental Health Risks 
    and Safety Risks (62 FR 19885, April 23, 1997).
        In addition, since tolerances and exemptions that are established 
    on the basis of a petition under FFDCA section 408(d), such as the 
    tolerances 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. Nevertheless, the Agency has 
    previously assessed whether establishing tolerances, exemptions from 
    tolerances, raising tolerance levels or expanding exemptions might 
    adversely impact small entities and concluded, as a generic matter, 
    that there is no adverse economic impact. The factual basis for the 
    Agency's generic certification for tolerance actions published on May 
    4, 1981 (46 FR 24950) and was provided to the Chief Counsel for 
    Advocacy of the Small Business Administration.
    
    B. Executive Order 12875
    
        Under Executive Order 12875, entitled Enhancing the 
    Intergovernmental Partnership (58 FR 58093, October 28, 1993), EPA may 
    not issue a regulation that is not required by statute and that creates 
    a mandate upon a State, local, or tribal government, unless the Federal 
    government provides the funds necessary to pay the direct compliance 
    costs incurred by those governments. If the mandate is unfunded, EPA 
    must provide to OMB a description of the extent of EPA's prior 
    consultation with representatives of affected State, local, and tribal 
    governments, the nature of their concerns, copies of any written 
    communications from the governments, and a statement supporting the 
    need to issue the regulation. In addition, Executive Order 12875 
    requires EPA to develop an effective process permitting elected 
    officials and other representatives of State, local, and tribal 
    governments ``to provide meaningful and timely input in the development 
    of regulatory proposals containing significant unfunded mandates.''
        Today's rule does not create an unfunded Federal mandate on State, 
    local, or tribal governments. The proposed rule does not impose any 
    enforceable duties on these entities. Accordingly, the requirements of 
    section 1(a) of Executive Order 12875 do not apply to this rule.
    
    C. Executive Order 13084
    
        Under Executive Order 13084, entitled Consultation and Coordination 
    with Indian Tribal Governments (63 FR 27655, May 19, 1998), EPA may not 
    issue a regulation that is not required by statute, that significantly 
    or uniquely affects the communities of Indian tribal governments, and 
    that imposes substantial direct compliance costs on those communities, 
    unless the Federal government provides the funds necessary to pay the 
    direct compliance costs incurred by the tribal governments. If the 
    mandate is unfunded, EPA must provide to OMB, in a separately 
    identified section of the preamble to the rule, a description of the 
    extent of EPA's prior consultation with representatives of affected 
    tribal governments, a summary of the nature of their concerns, and a 
    statement supporting the need to issue the regulation. In addition, 
    Executive Order 13084 requires EPA to develop an effective process 
    permitting elected officials and other representatives of Indian tribal 
    governments ``to provide meaningful and timely input in the development 
    of regulatory policies on matters that significantly or uniquely affect 
    their communities.''
        Today's rule does not significantly or uniquely affect the 
    communities of Indian tribal governments. This action does not involve 
    or impose any requirements that affect Indian tribes. Accordingly, the 
    requirements of section 3(b) of Executive Order 13084 do not apply to 
    this rule.
    
    VIII. Submission to Congress and the Comptroller General
    
        The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
    Small Business Regulatory Enforcement Fairness Act of 1996, generally 
    provides that before a rule may take effect, the agency promulgating 
    the rule must submit a rule report, which includes a copy of the rule, 
    to each House of the Congress and to the Comptroller General of the 
    United States. EPA will submit a report containing this rule and other 
    required information to the U.S. Senate, the U.S. House of 
    Representatives, and the Comptroller General of the United States prior 
    to publication of the rule in the Federal Register. This 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 record 
    keeping requirements.
    
        Dated: December 3, 1998.
    
    Stephen L. Johnson,
    Acting Director, 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. 346a and 371.
    
        2. By adding Sec. 180.548, to read as follows:
    
    
    Sec. 180.548  Tralkoxydim; tolerances for residues.
    
        (a) General. Time-limited tolerances are established for residues 
    of the herbicide, tralkoxydim, 2-(Cyclohexen-1-one, 2-[1-
    (ethoxyimino)propyl]-3-hydroxy-5-(2,4,6-trimethylphenyl)-(9Cl) in or on 
    the raw agricultural commodities:
    
    
     
    ------------------------------------------------------------------------
                                                              Expiration/
                Commodity              Parts per million    Revocation Date
    ------------------------------------------------------------------------
    Barley, grain...................  0.02                2/28/03
    Barley, hay.....................  0.02                2/28/03
    Barley, straw...................  0.05                2/28/03
    Wheat, forage...................  0.05                2/28/03
    Wheat, grain....................  0.02                2/28/03
    Wheat, hay......................  0.02                2/28/03
    Wheat, straw....................  0.05                2/28/03
    ------------------------------------------------------------------------
    
    
        (b) Section 18 emergency exemptions. [Reserved]
    
    [[Page 69200]]
    
        (c) Tolerances with regional registrations. [Reserved]
        (d) Indirect or inadvertent residues. [Reserved]
    
    [FR Doc. 98-33121 Filed 12-15-98; 8:45 am]
    BILLING CODE 6560-50-F
    
    
    

Document Information

Effective Date:
12/16/1998
Published:
12/16/1998
Department:
Environmental Protection Agency
Entry Type:
Rule
Action:
Final rule.
Document Number:
98-33121
Dates:
This regulation is effective December 16, 1998. Objections and requests for hearings must be received by EPA on or before February 16, 1999.
Pages:
69194-69200 (7 pages)
Docket Numbers:
OPP-300764, FRL-6048-4
RINs:
2070-AB78
PDF File:
98-33121.pdf
CFR: (1)
40 CFR 180.548