97-28641. Avermectin; Pesticide Tolerances for Emergency Exemptions  

  • [Federal Register Volume 62, Number 209 (Wednesday, October 29, 1997)]
    [Rules and Regulations]
    [Pages 56082-56089]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 97-28641]
    
    
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    ENVIRONMENTAL PROTECTION AGENCY
    
    40 CFR Part 180
    
    [OPP-300567; FRL-5750-8]
    RIN 2070-AB78
    
    
    Avermectin; Pesticide Tolerances for Emergency Exemptions
    
    AGENCY: Environmental Protection Agency (EPA).
    
    ACTION: Final rule.
    
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    SUMMARY: This regulation establishes a time-limited tolerance for the 
    combined residues of avermectin in or on basil. This action is in 
    response to an emergency exemption request under section 18 of the 
    Federal Insecticide, Fungicide, and Rodenticide Act permitting use of 
    the pesticide on basil. This regulation establishes a maximum 
    permissible level for residues of avermectin B1 and its 
    delta-8,9-isomer in this food commodity pursuant to section 408(l)(6) 
    of the Federal Food, Drug, and Cosmetic Act, as amended by the Food 
    Quality Protection Act of 1996. The tolerance will expire and is 
    revoked on September 30, 1998.
    
    DATES: This regulation is effective October 29, 1997. Objections and 
    requests for hearings must be received by EPA on or before December 29, 
    1997.
    
    ADDRESSES: Written objections and hearing requests, identified by the 
    docket control number, [OPP-300567], 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-300567], 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. 1132, Crystal 
    Mall #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-300567]. 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: Daniel Rosenblatt, 
    Registration Division (7505C), Office of Pesticide Programs, 
    Environmental Protection Agency, 401 M St., SW., Washington, DC 20460. 
    Office location, telephone
    
    [[Page 56083]]
    
    number, and e-mail address: CM #2, 1921 Jefferson Davis Hwy., 
    Arlington, VA, (703) 308-9375, e-mail: rosenblatt.dan@epamail.epa.gov.
    
    SUPPLEMENTARY INFORMATION: EPA, on its own initiative, pursuant to 
    section 408(e) and (l)(6) of the Federal Food, Drug, and Cosmetic Act 
    (FFDCA), 21 U.S.C. 346a(e) and (l)(6), is establishing a tolerance for 
    the combined residues of the miticide avermectin B1 and its 
    delta-8,9-isomer, in or on basil at 0.05 parts per million (ppm). This 
    tolerance will expire and is revoked on September 30, 1998. EPA will 
    publish a document in the Federal Register to remove the revoked 
    tolerance from the Code of Federal Regulations.
    
    I. Background and Statutory Authority
    
        The Food Quality Protection Act of 1996 (FQPA) (Pub. L. 104-170) 
    was signed into law August 3, 1996. FQPA amends both the Federal Food, 
    Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 301 et seq., and the Federal 
    Insecticide, Fungicide, and Rodenticide Act (FIFRA), 7 U.S.C. 136 et 
    seq. The FQPA amendments went into effect immediately. Among other 
    things, FQPA amends FFDCA to bring all EPA pesticide tolerance-setting 
    activities under a new section 408 with a new safety standard and new 
    procedures. These activities are described below and discussed in 
    greater detail in the final rule establishing the time-limited 
    tolerance associated with the emergency exemption for use of 
    propiconazole on sorghum (61 FR 58135, November 13, 1996)(FRL-5572-9).
        New 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. . . .''
        Section 18 of FIFRA authorizes EPA to exempt any Federal or State 
    agency from any provision of FIFRA, if EPA determines that ``emergency 
    conditions exist which require such exemption.'' This provision was not 
    amended by FQPA. EPA has established regulations governing such 
    emergency exemptions in 40 CFR part 166.
        Section 408(l)(6) of the FFDCA requires EPA to establish a time-
    limited tolerance or exemption from the requirement for a tolerance for 
    pesticide chemical residues in food that will result from the use of a 
    pesticide under an emergency exemption granted by EPA under section 18 
    of FIFRA. Such tolerances can be established without providing notice 
    or period for public comment.
        Because decisions on section 18-related tolerances must proceed 
    before EPA reaches closure on several policy issues relating to 
    interpretation and implementation of the FQPA, EPA does not intend for 
    its actions on such tolerance to set binding precedents for the 
    application of section 408 and the new safety standard to other 
    tolerances and exemptions.
    
    II. Emergency Exemption for Avermectin on Basil and FFDCA 
    Tolerances
    
        Basil is a leafy herb that is produced for the fresh and dried 
    markets. California submitted information to EPA that indicates that 
    the leafminer (Liriomyza sp.) poses a significant threat to the 
    profitable production of basil. Basil affected by leafminer can be 
    rendered unmarketable because they feed on the plant's leaves and may 
    also make them susceptible to disease. California determined that the 
    conditions for a leafminer outbreak were favorable and invoked its 
    authorities under 40 CFR 166.40 to declare a crisis situation. After 
    considering the implications connected with the use of this pesticide 
    under a crisis situation, EPA is establishing this tolerance for the 
    use of avermectin on basil for control of leafminer in California.
        As part of its assessment of this emergency exemption, EPA assessed 
    the potential risks presented by residues of avermectin in or on basil. 
    In doing so, EPA considered the new safety standard in FFDCA section 
    408(b)(2), and EPA decided that the necessary tolerance under FFDCA 
    section 408(l)(6) would be consistent with the new safety standard and 
    with FIFRA section 18. Consistent with the need to move quickly on the 
    emergency exemption in order to address an urgent non-routine situation 
    and to ensure that the resulting food is safe and lawful, EPA is 
    issuing this tolerance without notice and opportunity for public 
    comment under section 408(e), as provided in section 408(l)(6). 
    Although this tolerance will expire and is revoked on September 30, 
    1998, under FFDCA section 408(l)(5), residues of the pesticide not in 
    excess of the amounts specified in the tolerance remaining in or on 
    basil after that date will not be unlawful, provided the pesticide is 
    applied in a manner that was lawful under FIFRA. EPA will take action 
    to revoke this tolerance earlier if any experience with, scientific 
    data on, or other relevant information on this pesticide indicate that 
    the residues are not safe.
        Because this tolerance is being approved under emergency conditions 
    EPA has not made any decisions about whether avermectin meets EPA's 
    registration requirements for use on basil or whether a permanent 
    tolerance for this use would be appropriate. Under these circumstances, 
    EPA does not believe that this tolerance serves as a basis for 
    registration of avermectin by a State for special local needs under 
    FIFRA section 24(c). Nor does this tolerance serve as the basis for any 
    State other than California to use this pesticide on this crop under 
    section 18 of FIFRA without following all provisions of section 18 as 
    identified in 40 CFR part 166. For additional information regarding the 
    emergency exemption for avermectin, contact the Agency's Registration 
    Division at the address provided above.
    
    III. Risk Assessment and Statutory Findings
    
        EPA performs a number of analyses to determine the risks from 
    aggregate exposure to pesticide residues. First, EPA determines the 
    toxicity of pesticides based primarily on toxicological studies using 
    laboratory animals. These studies address many adverse health effects, 
    including (but not limited to) reproductive effects, developmental 
    toxicity, toxicity to the nervous system, and carcinogenicity. Second, 
    EPA examines exposure to the pesticide through the diet (e.g., food and 
    drinking water) and through exposures that occur as a result of 
    pesticide use in residential settings.
    
    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 effect level'' or ``NOEL'').
        Once a study has been evaluated and the observed effects have been 
    determined to be threshold effects, EPA generally divides the NOEL from 
    the
    
    [[Page 56084]]
    
    study with the lowest NOEL 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 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 NOEL 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 NOEL) 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 3 
    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/NOEL 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 (non-nursing 
    infants <1 year="" old)="" was="" not="" regionally="" based.="" [[page="" 56085]]="" iv.="" 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="" avermectin="" and="" to="" make="" a="" determination="" on="" aggregate="" exposure,="" consistent="" with="" section="" 408(b)(2),="" for="" a="" time-limited="" tolerance="" for="" combined="" residues="" of="" avermectin="">1 and its delta-8,9-isomer 
    on basil at 0.05 ppm. 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 toxic effects caused by avermectin 
    B1 and its delta-8,9-isomer are discussed below.
        1. Acute toxicity. For acute dietary risk assessment, EPA 
    recommends use of a NOEL of 0.06 mg/kg/day from the developmental 
    toxicity study in mice. The effects observed at the Lowest Effect Level 
    (LEL) of 0.10 mg/kg/day involved cleft palate. For the purposes of this 
    action, an MOE of 300 is considered necessary to be adequately 
    protective for dietary (food only) exposure.
        2. Short - and intermediate - term toxicity. For short- and 
    intermediate-term MOE calculations, EPA recommends use of the 
    developmental NOEL of 0.2 mg/kg/day from the oral developmental 
    toxicity study in mice. At the LEL of 0.4 mg/kg/day, there was an 
    increased incidence of cleft palate.
        3. Chronic toxicity. EPA has established the RfD for avermectin at 
    0.0004 milligrams/kilogram/day (mg/kg/day). This RfD is based on a 2-
    generation rat reproductive toxicity study with a NOEL of 0.12 mg/kg/
    day and an uncertainty factor of 300. In addition to the uncertainty 
    factor of 100 for inter- and intra-species variations, a Modifying 
    Factor (MF) of 3 was used. The MF was used because of the severity of 
    the effects (pup deaths) and the steep dose-response curve. At the LEL 
    of 0.40 mg/kg/day, there was decreased pup body weight and viability 
    during lactation as well as an increased incidence of retinal rosettes 
    in F2b weanlings.
        4. Carcinogenicity. Avermectin has been classified by EPA as a 
    Group E (``evidence of non-carcinogenicity for humans'') chemical. 
    Therefore, a cancer risk assessment is not needed.
    
    B. Exposures and Risks
    
        1.  From food and feed uses. Tolerances have been established (40 
    CFR 180.449) for the combined residues of avermectin B1 and 
    its delta-8,9-isomer, in or on a variety of raw agricultural 
    commodities, ranging from 0.005 ppm in cottonseed to 0.05 ppm in 
    celery. Risk assessments were conducted by EPA to assess dietary 
    exposures and risks from avermectin B1 and its delta-8,9-
    isomer 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. In a separate and earlier registration 
    action, the Agency required the development of more highly refined 
    residue and exposure information to support the pesticide. In response, 
    in October 1996, EPA received a Monte Carlo analysis for all uses of 
    avermectin at that time. Since that analysis was generated before this 
    section 18 action was submitted, EPA does not have information on acute 
    exposures for basil. Further, the Agency is not currently updating or 
    revising Monte Carlo analysis developed by registrants. Therefore, the 
    acute exposure assessment for this action does not include data 
    associated with the consumption of basil. In spite of the above 
    exception, data available to EPA suggest a high-end exposure estimate 
    of 0.000078 mg/kg/day for uses of avermectin. This results in a dietary 
    (food only) MOE of 769 for females 13 years and older, the population 
    subgroup of concern. In EPA's judgement, the addition of basil to acute 
    exposure and risk calculations would not produce acute risks (food 
    only) that exceed a level of concern.
        ii. Chronic exposure and risk. As part of this action, EPA reviewed 
    information that establishes chronic dietary exposure estimates for 
    avermectin. This chronic dietary (food only) risk assessment used 
    anticipated residue refinement for commodities with tolerances for 
    avermectin, but did not incorporate any refinement for percent of crop 
    treated (default of 100% was assumed). Therefore, the resulting 
    exposure estimates should be viewed as partially refined; further 
    refinement for percent of crop treated would result in lower dietary 
    exposure estimates. The existing avermectin tolerances plus the 
    proposed tolerances associated with the section 18 use of the chemical 
    result in an Anticipated Residue Contribution that ranges from 5% of 
    the RfD for the U.S. Population to 12% of the RfD for non-nursing 
    infants less than a year old.
        2. From drinking water. In examining aggregate exposure, FQPA 
    directs EPA to consider available information concerning exposures from 
    the pesticide residues in food and all other non-occupational 
    exposures. The primary non-food sources of exposure the Agency looks at 
    include drinking water (whether from ground or surface water), and 
    exposure through pesticide use in gardens, lawns, or buildings 
    (residential and other indoor uses). Based on data available to EPA, 
    avermectin is moderately persistent and not very mobile. It is not 
    likely to be found extensively in ground water, but could be found in 
    surface water. Under anaerobic conditions in the absence of light, 
    avermectin does not degrade. No Health Advisories or Maximum 
    Contaminant Levels for avermectin in drinking water have been 
    established.
        Because the Agency lacks sufficient water-related exposure data to 
    complete a comprehensive drinking water risk assessment for many 
    pesticides, EPA has commenced and nearly completed a process to 
    identify a reasonable yet conservative bounding figure for the 
    potential contribution of water-related exposure to the aggregate risk 
    posed by a pesticide. In developing the bounding figure, EPA estimated 
    residue levels in water for a number of specific pesticides using 
    various data sources. The Agency then applied the estimated residue 
    levels, in conjunction with appropriate toxicological endpoints (RfD's 
    or acute dietary NOEL's) and assumptions about body weight and 
    consumption, to calculate, for each pesticide, the increment of 
    aggregate risk contributed by consumption of contaminated water. While 
    EPA has not yet pinpointed the appropriate bounding figure for exposure 
    from contaminated water, the ranges the Agency is continuing to examine 
    are all below the level that would cause avermectin to exceed the RfD 
    if the tolerance being considered in this document were granted. The 
    Agency has therefore concluded that the potential exposures associated 
    with avermectin in water, even at the higher levels the Agency is 
    considering as a conservative upper bound, would not prevent the Agency 
    from determining that there is a reasonable certainty of no harm if the 
    tolerance is granted.
        3. From non-dietary exposure. Avermectin is currently registered 
    for use on the following residential non-food sites: ornamental crops 
    (herbaceous and woody), turf, households (indoor and outdoor), and
    
    [[Page 56086]]
    
    non-food areas of food handling establishments.
        i. Chronic exposure and risk. Given the uses for avermectin, a 
    chronic non-dietary exposure scenario would not be expected.
        ii. Short- and intermediate-term exposure and risk. EPA assessed 
    indoor residential risk characterization data to evaluate short- and 
    intermediate-term exposure and risk. Based on the assumptions for 
    exposure total oral, dermal, and respiratory estimated absorbed daily 
    exposure could total .00023 mg/kg/day. This correlates to a total 
    short- and intermediate-term indoor residential MOE of 870 for the U.S. 
    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.'' The Agency believes that ``available 
    information'' in this context might include not only toxicity, 
    chemistry, and exposure data, but also scientific policies and 
    methodologies for understanding common mechanisms of toxicity and 
    conducting cumulative risk assessments. For most pesticides, although 
    the Agency has some information in its files that may turn out to be 
    helpful in eventually determining whether a pesticide shares a common 
    mechanism of toxicity with any other substances, EPA does not at this 
    time have the methodologies to resolve the complex scientific issues 
    concerning common mechanism of toxicity in a meaningful way. EPA has 
    begun a pilot process to study this issue further through the 
    examination of particular classes of pesticides. The Agency hopes that 
    the results of this pilot process will increase the Agency's scientific 
    understanding of this question such that EPA will be able to develop 
    and apply scientific principles for better determining which chemicals 
    have a common mechanism of toxicity and evaluating the cumulative 
    effects of such chemicals. The Agency anticipates, however, that even 
    as its understanding of the science of common mechanisms increases, 
    decisions on specific classes of chemicals will be heavily dependent on 
    chemical specific data, much of which may not be presently available.
        Although at present the Agency does not know how to apply the 
    information in its files concerning common mechanism issues to most 
    risk assessments, there are pesticides as to which the common mechanism 
    issues can be resolved. These pesticides include pesticides that are 
    toxicologically dissimilar to existing chemical substances (in which 
    case the Agency can conclude that it is unlikely that a pesticide 
    shares a common mechanism of activity with other substances) and 
    pesticides that produce a common toxic metabolite (in which case common 
    mechanism of activity will be assumed).
        EPA does not have, at this time, available data to determine 
    whether avermectin has a common mechanism of toxicity with other 
    substances or how to include this pesticide in a cumulative risk 
    assessment. Unlike other pesticides for which EPA has followed a 
    cumulative risk approach based on a common mechanism of toxicity, 
    avermectin 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 avermectin has a common mechanism of toxicity 
    with other substances.
    
    C. Aggregate Risks and Determination of Safety for U.S. Population
    
        1. Acute risk. The population subgroup of concern is females 13 
    years and older. The MOE for this subgroup from food exposures is 769. 
    Despite the potential for exposures to avermectin from drinking water, 
    EPA does not expect the acute aggregate risk to exceed levels of 
    concern.
        2. Chronic risk. Using the ARC exposure assumptions described 
    above, EPA has concluded that aggregate exposure to avermectin from 
    food will utilize 5% of the RfD for the U.S. population. The major 
    identifiable subgroup with the highest aggregate exposure is non-
    nursing infants <1 year="" old="" ``discussed="" below''.="" epa="" generally="" has="" no="" concern="" for="" exposures="" below="" 100%="" of="" the="" rfd="" because="" the="" rfd="" represents="" the="" level="" at="" or="" below="" which="" daily="" aggregate="" dietary="" exposure="" over="" a="" lifetime="" will="" not="" pose="" appreciable="" risks="" to="" human="" health.="" based="" on="" the="" nature="" of="" the="" residential="" uses,="" a="" chronic="" scenario="" would="" not="" be="" expected.="" despite="" the="" potential="" for="" exposure="" to="" avermectin="" in="" drinking="" water="" and="" from="" non-dietary,="" non-occupational="" exposure,="" epa="" does="" not="" expect="" the="" aggregate="" exposure="" to="" exceed="" 100%="" of="" the="" rfd.="" epa="" concludes="" that="" there="" is="" a="" reasonable="" certainty="" that="" no="" harm="" will="" result="" from="" aggregate="" exposure="" to="" avermectin="" residues.="" 3.="" short-="" and="" intermediate-term="" risk.="" short-="" and="" intermediate-term="" aggregate="" exposure="" takes="" into="" account="" chronic="" dietary="" food="" and="" water="" (considered="" to="" be="" a="" background="" exposure="" level)="" plus="" indoor="" and="" outdoor="" residential="" exposure.="" as="" referenced="" above,="" for="" short-="" and="" intermediate-term="" exposures,="" epa="" assessed="" information="" that="" addresses="" this="" topic="" in="" relation="" to="" human="" exposure="" associated="" with="" residential="" use="" through="" oral,="" dermal,="" and="" respiratory="" exposures.="" the="" anticipated="" moe="" was="" 803="" for="" the="" u.s.="" population.="" epa="" considers="" this="" moe="" to="" be="" adequately="" protective.="" d.="" aggregate="" cancer="" risk="" for="" u.s.="" population="" avermectin="" has="" been="" classified="" as="" a="" group="" e="" ``evidence="" of="" non-="" carcinogenicity="" for="" humans''="" chemical="" by="" epa.="" therefore,="" a="" cancer="" risk="" assessment="" is="" not="" needed.="" e.="" aggregate="" risks="" and="" determination="" of="" safety="" for="" infants="" and="" children="" 1.="" safety="" factor="" for="" infants="" and="" children--="" i.="" in="" general.="" in="" assessing="" the="" potential="" for="" additional="" sensitivity="" of="" infants="" and="" children="" to="" residues="" of="" avermectin,="" epa="" considered="" data="" from="" developmental="" toxicity="" studies="" in="" the="" rat="" and="" rabbit="" and="" a="" two-="" 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="" during="" 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.="" 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.="" epa="" believes="" that="" reliable="" data="" support="" using="" the="" standard="" 100-="" fold="" safety="" factor="" (usually="" 100="" for="" combined="" inter-="" and="" intra-species="" variability)="" and="" not="" the="" additional="" tenfold="" safety="" factor="" when="" epa="" has="" a="" complete="" data="" base="" under="" existing="" guidelines="" and="" when="" the="" severity="" of="" the="" effect="" in="" infants="" or="" children="" or="" the="" potency="" or="" unusual="" toxic="" properties="" of="" a="" compound="" do="" not="" raise="" concerns="" regarding="" the="" adequacy="" of="" the="" standard="" safety="" factor.="" ii.="" developmental="" toxicity="" studies.="" in="" the="" mouse="" developmental="" toxicity="" analysis,="" the="" maternal="" (systemic)="" noel="" was="" 0.05="" mg/kg/day="" based="" on="" mortality="" [[page="" 56087]]="" at="" the="" lowest-observed="" effect="" level="" (loel)="" of="" 0.075="" mg/kg/day.="" the="" developmental="" (fetal)="" noel="" was="" 0.2="" mg/kg/day="" based="" on="" cleft="" palate="" at="" the="" loel="" of="" 0.4="" mg/kg/day.="" the="" delta-8,9-isomer="" was="" also="" tested="" for="" developmental="" toxicity="" in="" the="" mouse.="" in="" the="" mouse="" developmental="" study="" for="" the="" isomer,="" the="" maternal="" (systemic)="" noel="" was="" 0.10="" mg/kg/day,="" based="" on="" mortality="" at="" the="" loel="" of="" 0.20="" mg/kg/day.="" the="" developmental="" (fetal)="" noel="" was="" 0.06="" mg/kg/day,="" based="" on="" cleft="" palate="" at="" the="" loel="" of="" 0.10="" mg/="" kg/day.="" in="" the="" rat="" developmental="" study,="" the="" maternal="" (systemic)="" noel="" was="" greater="" than="" or="" equal="" to="" 1.6="" mg/kg/day.="" the="" developmental="" (fetal)="" noel="" was="" 1.6="" mg/kg/day.="" in="" the="" rabbit="" developmental="" study,="" the="" maternal="" (systemic)="" noel="" was="" 1.0="" mg/kg/day,="" based="" on="" decreased="" body="" weight="" and="" decreased="" food="" and="" water="" consumption="" at="" the="" loel="" of="" 2.0="" mg/kg/day.="" the="" developmental="" (fetal)="" noel="" was="" 1.0="" mg/kg/day,="" based="" on="" clubbed="" foot,="" and="" delayed="" ossification="" of="" sternebrae,="" metacarpals,="" and="" phalanges="" at="" the="" loel="" of="" 2.0="" mg/kg/day.="" iii.="" reproductive="" toxicity="" study.="" in="" the="" 2-generation="" rat="" reproductive="" toxicity="" study,="" the="" maternal="" (systemic)="" noel="" was="" 0.4="" mg/="" kg/day="" highest="" dose="" tested="" (hdt).="" the="" developmental="" (pup)="" noel="" was="" 1.2="" mg/kg/day,="" based="" on="" decreased="" viability="" indices,="" decreased="" pup="" body="" weight,="" and="" retinal="" fold="" in="" weanlings="" at="" the="" loel="" of="" 0.4="" mg/kg/day.="" the="" reproductive="" (pup)="" noel="" was="" 0.4="" mg/kg/day="" (hdt).="" iv.="" pre-="" and="" post-natal="" sensitivity.="" both="" the="" delta-8,9-isomer="" of="" avermectin="" and="" avermectin="" per="" se="" exhibit="" cleft="" palate="" in="" cf1="" mouse="" developmental="" studies.="" the="" noel="" for="" cleft="" plate="" for="" the="" delta-8,9-="" isomer="" is="" 0.06="" mg/kg/day="" with="" the="" loel="" at="" 0.10="" mg/kg/day.="" for="" avermectin="" per="" se,="" the="" noel="" for="" cleft="" palate="" is="" 0.2="" mg/kg/day="" with="" the="" loel="" at="" 0.4="" mg/kg/day.="" therefore,="" pre-natal="" sensitivity="" to="" the="" regulated="" residue="" for="" avermectin="" is="" demonstrated="" when="" considering="" these="" developmental="" findings="" in="" the="" cf1="" mouse.="" an="" additional="" 3-fold="" uncertainty="" factor="" has="" been="" added="" to="" account="" for="" these="" developmental="" findings.="" an="" acute="" dietary="" risk="" assessment="" is="" needed="" based="" on="" the="" results="" of="" the="" developmental="" study="" in="" mice="" with="" the="" delta-8,9-isomer.="" this="" risk="" assessment="" will="" evaluate="" acute="" dietary="" risk="" to="" females="" 13="" years="" and="" older.="" for="" the="" purpose="" of="" the="" section="" 18,="" an="" moe="" of="" 300="" is="" considered="" necessary="" to="" be="" adequately="" protective="" for="" dietary="" (food="" only)="" exposure.="" to="" evaluate="" the="" pre-natal="" risks,="" the="" acute="" dietary="" moe="" calculations="" for="" females="" 13="" years="" and="" older="" has="" been="" conducted="" using="" the="" lowest="" noel="" for="" all="" developmental="" studies="" for="" cleft="" palate="" (0.06="" mg/kg/day).="" the="" results="" of="" the="" rat="" reproduction="" study="" required="" that="" a="" modifying="" factor="" of="" 3="" be="" added="" to="" the="" usual="" uncertainty="" factor="" of="" 100="" used="" for="" the="" rfd.="" epa="" used="" this="" modifying="" factor="" in="" developing="" this="" analysis.="" typically,="" the="" agency="" uses="" a="" modifying="" factor="" of="" 10="" when="" no="" study="" is="" available="" and="" uses="" a="" modifying="" factor="" of="" 3="" when="" a="" study="" exists="" which="" shows="" effects="" in="" the="" fetus="" before="" they="" appear="" in="" the="" parent.="" 2.="" acute="" risk.="" the="" acute="" dietary="" moe="" for="" females="" 13="" years="" and="" older="" (accounts="" for="" both="" maternal="" and="" fetal="" exposure)="" is="" 769.="" this="" moe="" calculation="" is="" based="" on="" the="" developmental="" noel="" in="" mice="" of="" 0.06="" mg/kg/="" day.="" this="" estimate="" is="" based="" on="" monte="" carlo="" modeling="" incorporating="" anticipated="" residue="" and="" percent="" of="" crop="" treated="" refinement.="" in="" epa's="" judgement,="" the="" large="" acute="" dietary="" moe="" provides="" assurance="" that="" there="" is="" a="" reasonable="" certainty="" of="" no="" harm="" for="" females="" 13="" years="" and="" older="" and="" the="" pre-natal="" development="" of="" infants.="" 3.="" chronic="" risk.="" using="" the="" conservative="" exposure="" assumptions="" described="" above,="" epa="" has="" concluded="" that="" aggregate="" exposure="" to="" avermectin="" from="" food="" will="" utilize="" 12%="" of="" the="" rfd="" for="" non-nursing="" infants="" less="" than="" a="" year="" old="" and="" 8%="" of="" the="" rfd="" for="" children="" 1-6="" years="" old.="" epa="" generally="" has="" no="" concern="" for="" exposures="" below="" 100%="" of="" the="" rfd="" because="" the="" rfd="" represents="" the="" level="" at="" or="" below="" which="" daily="" aggregate="" dietary="" exposure="" over="" a="" lifetime="" will="" not="" pose="" appreciable="" risks="" to="" human="" health.="" based="" on="" the="" nature="" of="" the="" residential="" uses,="" a="" chronic="" scenario="" would="" not="" be="" expected.="" despite="" the="" potential="" for="" exposure="" to="" avermectin="" in="" drinking="" water="" and="" from="" non-dietary,="" non-occupational="" exposure,="" epa="" does="" not="" expect="" the="" aggregate="" exposure="" to="" exceed="" 100%="" of="" the="" rfd.="" epa="" concludes="" that="" there="" is="" a="" reasonable="" certainty="" that="" no="" harm="" will="" result="" to="" infants="" and="" children="" from="" aggregate="" exposure="" to="" avermectin="" residues.="" 4.="" short-="" or="" intermediate-term="" risk.="" the="" anticipated="" moes="" for="" short-="" and="" intermediate-term="" exposures="" for="" infants="" and="" children="" do="" not="" pose="" a="" level="" of="" concern.="" the="" calculated="" moes="" range="" from="" 716="" for="" non-="" nursing="" infants="" to="" 787="" for="" children="" 7-12="" years="" old.="" v.="" other="" considerations="" a.="" metabolism="" in="" plants="" and="" animals="" the="" nature="" of="" the="" residue="" in="" plants="" and="" animals="" is="" adequately="" understood.="" as="" cited="" at="" 40="" cfr="" 180.449,="" the="" regulable="" residues="" are="" avermectin="">1 and its delta-8,9-isomer.
    
    B. Analytical Enforcement Methodology
    
        Merck Method 10001, rev. 2, a high pressure liquid chromatography 
    (HPLC)-fluorescence method, may be used to enforce the tolerance 
    expression. This method has been submitted to FDA for publication in 
    PAM Volume II.
    
    C. Magnitude of Residues
    
        Residues of avermectin B1 and its delta 8,9-isomer are 
    not expected to exceed 0.05 ppm on basil as a result of this section 18 
    use. Secondary residues are not expected in animal commodities as no 
    feed items are associated with this use.
    
    D. International Residue Limits
    
        No Codex MRLs have been established for avermectin residues on 
    basil.
    
    VI. Conclusion
    
        Therefore, the tolerance is established for combined residues of 
    avermectin B1 and its delta-8,9-isomer in basil at 0.05 ppm.
    
    VII. 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 December 29, 1997, 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). 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
    
    [[Page 56088]]
    
    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.
    
    VIII. Public Record and Electronic Submissions
    
        EPA has established a record for this rulemaking under docket 
    control number [OPP-300567] (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 Room 1132 of the Public Information and Records 
    Integrity Branch, Information Resources and Services Division (7502C), 
    Office of Pesticide Programs, Environmental Protection Agency, Crystal 
    Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA.
        Electronic comments may be sent directly to EPA at:
        opp-docket@epamail.epa.gov.
    
    
        Electronic comments must be submitted as an ASCII file avoiding the 
    use of special characters and any form of encryption.
        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 address in ``ADDRESSES'' at the beginning of this document.
    
    IX. Regulatory Assessment Requirements
    
        This final rule establishes a time-limited tolerance under FFDCA 
    section 408(l)(6). 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 
    prior consultation as specified by Executive Order 12875, entitled 
    Enhancing the Intergovernmental Partnership (58 FR 58093, October 28, 
    1993), or 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 these tolerances and exemptions that are 
    established under FFDCA section 408 (1)(6), 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. 601et 
    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 acations published on May 4, 1981 (46 FR 
    24950), and was provided to the Chief Counsel for Advocacy of the Small 
    Business Administration.
    
    X. Submission to Congress and the General Accounting Office
    
        Under 5 U.S.C. 801(a)(1)(A), as added by the Small Business 
    Regulatory Enforcement Fairness Act of 1996, the Agency has submitted 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 General Accounting Office prior to publication of this rule in 
    today's Federal Register. This 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: October 22, 1997.
    
    James Jones,
    Acting Director, Registration Division, Office of Pesticide Programs.
    
        Therefore, 40 CFR chapter I is amended as follows:
    
    PART 180 -- [AMENDED]
    
        1. The authority citation for part 180 continues to read as 
    follows:
    
        Authority: 21 U.S.C. 346a and 371.
    
        2. Section 180.449 is amended in paragraph (b) by alphabetically 
    adding a commodity to the table to read as follows:
    
    Sec. 180.449 Avermectin B1 and its delta-8,9-isomer; 
    tolerances for residues.
    
    *       *        *       *       *
        (b) *    *    *
    
                                                                            
    ------------------------------------------------------------------------
                                                              Expiration/   
                Commodity              Parts per million    revocation date 
    ------------------------------------------------------------------------
    Basil...........................  0.05 ppm            9/30/98           
                                                                            
             *        *        *        *        *        *        *        
    ------------------------------------------------------------------------
    
    
    [[Page 56089]]
    
    *       *        *       *       *
    
    [FR Doc. 97-28641 Filed 10-28-97; 8:45 am]
    BILLING CODE 6560-50-F
    
    
    

Document Information

Effective Date:
10/29/1997
Published:
10/29/1997
Department:
Environmental Protection Agency
Entry Type:
Rule
Action:
Final rule.
Document Number:
97-28641
Dates:
This regulation is effective October 29, 1997. Objections and requests for hearings must be received by EPA on or before December 29, 1997.
Pages:
56082-56089 (8 pages)
Docket Numbers:
OPP-300567, FRL-5750-8
RINs:
2070-AB78
PDF File:
97-28641.pdf
CFR: (1)
40 CFR 180.449