98-31683. Notice of Filing of Pesticide Petitions  

  • [Federal Register Volume 63, Number 231 (Wednesday, December 2, 1998)]
    [Notices]
    [Pages 66535-66540]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 98-31683]
    
    
    -----------------------------------------------------------------------
    
    ENVIRONMENTAL PROTECTION AGENCY
    
    [PF-847; FRL-6043-2]
    
    
    Notice of Filing of Pesticide Petitions
    
    AGENCY: Environmental Protection Agency (EPA).
    
    ACTION: Notice.
    
    -----------------------------------------------------------------------
    
    SUMMARY: This notice announces the initial filing of pesticide 
    petitions proposing the establishment of regulations for residues of 
    certain pesticide chemicals in or on various food commodities.
    
    DATES: Comments, identified by the docket control number PF-847, must 
    be received on or before January 4, 1999.
    ADDRESSES: By mail submit written comments to: Public Information and 
    Records Branch (7502C), Information Resources and Services Division, 
    Office of Pesticides Programs, Environmental Protection Agency, 401 M 
    St., SW., Washington, DC 20460. In person bring comments to: Rm. 119, 
    CM #2, 1921 Jefferson Davis Highway, Arlington, VA.
        Comments and data may also be submitted electronically to: cket@epamail.epa.gov. Follow the instructions under ``SUPPLEMENTARY 
    INFORMATION.'' No Confidential Business Information (CBI) should be 
    submitted through e-mail.
        Information submitted as a comment concerning this document may be 
    claimed confidential by marking any part or all of that information as 
    CBI. CBI should not be submitted through e-mail. Information marked as 
    CBI will not be disclosed except in accordance with procedures set 
    forth in 40 CFR part 2. A copy of the comment 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. All written comments will be available for public inspection in 
    Rm. 119 at the address given above, from 8:30 a.m. to 4 p.m., Monday 
    through Friday, excluding legal holidays.
    
    FOR FURTHER INFORMATION CONTACT: The product manager listed in the 
    table below:
    
    ------------------------------------------------------------------------
                                       Office location/
            Product Manager            telephone number          Address
    ------------------------------------------------------------------------
    Joanne I. Miller (PM 13)......  Rm. 237, CM #2, 703-    1921 Jefferson
                                     305-6224, e-mail:       Davis Hwy,
                                     Miller.joanne@epa.gov   Arlington, VA
                                     .                       22202
    Cynthia Giles-Parker (PM 22)..  Rm. 247, CM #2, 703-    Do.
                                     305-7740, e-mail:
                                     giles-
                                     [email protected]
                                     v.
    ------------------------------------------------------------------------
    
    
    SUPPLEMENTARY INFORMATION: EPA has received pesticide petitions as 
    follows proposing the establishment and/or amendment of regulations for 
    residues of certain pesticide chemicals in or on various raw food 
    commodities under section 408 of the Federal Food, Drug, and Comestic 
    Act (FFDCA), 21 U.S.C. 346a. EPA has determined that these petitions 
    contain data or information regarding the elements set forth in section 
    408(d)(2); however, EPA has not fully evaluated the sufficiency of the 
    submitted data at this time or whether the data supports granting of 
    the petition. Additional data may be needed before EPA rules on the 
    petition.
        The official record for this notice, as well as the public version, 
    has been established for this notice of filing under docket control 
    number PF-847 (including comments and data submitted electronically as 
    described below). 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 
    official record is located at the address in ``ADDRESSES''.
    
    [[Page 66536]]
    
        Electronic comments can 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. Comment and data 
    will also be accepted on disks in Wordperfect 5.1/6.1 file format or 
    ASCII file format. All comments and data in electronic form must be 
    identified by the docket control number PF-847 and appropriate petition 
    number. Electronic comments on this notice may be filed online at many 
    Federal Depository Libraries.
    
        Authority: 21 U.S.C. 346a.
    
    List of Subjects
    
        Environmental protection, Agricultural commodities, Food additives, 
    Feed additives, Pesticides and pests, Reporting and recordkeeping 
    requirements.
    
        Dated: November 13, 1998.
    
    James Jones,
    Director, Registration Division, Office of Pesticide Programs.
    
    Summaries of Petitions
    
        Below petitioner summaries of the pesticide petitions are printed 
    as required by section 408(d)(3) of the FFDCA. The summaries of the 
    petitions were prepared by the petitioners and represent the views of 
    the petitioners. EPA is publishing the petition summaries verbatim 
    without editing them in any way. The petition summary announces the 
    availability of a description of the analytical methods available to 
    EPA for the detection and measurement of the pesticide chemical 
    residues or an explanation of why no such method is needed.
    
    1. BASF Corporation
    
    PP 7F4870
    
        EPA has received a pesticide petition (PP 7F4870) from BASF 
    Corporation, P.O. Box 13528, Research Triangle Park, North Carolina 
    27709-3528 proposing pursuant to section 408(d) of the Federal Food, 
    Drug and Cosmetic Act (FFDCA), 21 U.S.C. 346a(d), to amend 40 CFR part 
    180 by establishing a tolerance for residues of quinclorac (3,7-
    dichloro-8-quinolone carboxylic acid), in or on the raw agricultural 
    commodity wheat and sorghum raw agricultural and food/feed commodities: 
    0.5 parts per million (ppm) in or on wheat grain, 0.1 ppm in or on 
    wheat straw, 1.0 ppm in or on wheat forage, 0.5 ppm in or on wheat hay, 
    1.0 ppm in or on wheat bran, 1.5 ppm in or on wheat germ, 0.75 ppm in 
    or on wheat shorts, 0.5 ppm in or on sorghum grain, 0.2 ppm in or on 
    sorghum forage and 0.05 ppm in or on sorghum fodder. EPA has determined 
    that the petition contains data or information regarding the elements 
    set forth in section 408(d)(2) of the FFDCA; however, EPA has not fully 
    evaluated the sufficiency of the submitted data at this time or whether 
    the data supports granting of the petition. Additional data may be 
    needed before EPA rules on the petition.
    
    A. Residue Chemistry
    
        1. Plant and animal metabolism. The metabolism of quinclorac in 
    plants and animals is well understood. Based on a nature of the residue 
    study in wheat and supported by similar studies in rice and sorghum, 
    the residue of concern from quinclorac use in non-oily grains consists 
    only of the parent compound.
        2. Analytical method. An adequate analytical method for enforcement 
    of the tolerances exists. The analytical method used for quantitative 
    determinations was designed to measure quinclorac residues present as 
    the parent compound.
        3. Magnitude of residues --(i) Raw agricultural commodities. Crop 
    field trials were conducted in wheat and sorghum and treatments were 
    made at the maximum proposed label rate. The maximum amount of 
    quinclorac residue found in wheat and sorghum raw agricultural 
    commodities are: wheat forage 0.88 ppm, wheat hay 032 ppm, wheat grain 
    0.25 ppm, wheat straw 0.08 ppm, sorghum forage 0.15 ppm, sorghum grain 
    0.26 ppm, sorghum fodder 0.05 ppm.
        (ii) Processed fractions. Processing studies were conducted for 
    both wheat and sorghum to determine whether quinclorac residues 
    concentrate during the commercial processing of these commodities. In 
    sorghum, no concentration of residues was found in the production of 
    flour and starch. In wheat, no concentration was found in the 
    production of middlings and flour. Quinclorac residues concentrated 2-
    fold in the production of bran, 3-fold in the production of germ, and 
    only slightly, 1.3-fold, in shorts. No additional data were needed in 
    support of residues in meat, milk, poultry, and eggs. Maximum residue 
    levels in wheat and sorghum raw agricultural commodities and process 
    fractions were well below levels of current rice tolerances (5 ppm for 
    grain, 12 ppm for straw, and 15 ppm for bran) which originally dictated 
    the animal feeding study dosing levels and subsequent setting of animal 
    product tolerances.
    
    B. Toxicological Profile
    
        1. Acute toxicity. Based on available acute toxicity data 
    quinclorac does not pose any acute toxicity risks. Several acute 
    toxicology studies place technical-grade quinclorac in Toxicity 
    Category III for acute oral, acute dermal, acute inhalation toxicity, 
    and for eye irritation. Technical 3,7-dichloro-8-quinoline carboxylic 
    acid is in category IV for primary dermal irritation and is a skin 
    sensitizer. The currently registered end use formulations of quinclorac 
    (50% wettable powder and 75% dry flowable formulations) have tested 
    negative for skin sensitization.
        2. Chronic feeding -- Nonrodent. A 1-year feeding study in dogs fed 
    0, 34, 142, and 513 (males) and 0, 35, 140, and 469 (females) 
    milligrams/kilogram/day (mg/kg/day) resulted in a No Observed Adverse 
    Effect Level (NOAEL) of 140 mg/kg/day based on reduced body weight 
    gains, adverse effect on food efficiency, hematological and clinical 
    chemistry values, increased liver and kidney weights, and microscopic 
    findings in liver and kidneys at 513 mg/kg/day (males) and 469 mg/kg/
    day (females), the highest dosages tested (HDT).
        3. Chronic feeding/oncogenicity - Rats. A chronic feeding/
    carcinogenicity study in rats fed dosages of 1, 56, 186, 385, and 487 
    mg/kg/day (males) and 0, 60, 235, 478, and 757 mg/kg/day (females) 
    resulted in a NOAEL of 478 mg/kg/day (females) and 385 mg/kg/day 
    (males) based on slight decreases in weight for females at 757 mg/kg/
    day (HDT) and an equivocal (uncertain) increase in acinar cell 
    hyperplasia of the pancreas in males at 487 mg/kg/day (HDT). There were 
    no carcinogenic effects noted for female rats under the conditions of 
    the study up to 757 mg/kg/day (HDT).
        4. Oncogenicity - Mice. A carcinogenic study in mice fed dosages of 
    0, 37.5, 150, 600, and 1,200 mg/kg/day resulted in no carcinogenic 
    effects observed under the conditions of the study up to and including 
    1,200 mg/kg/day (HDT) and a systemic NOAEL of 37.5 mg/kg/day based on a 
    reduction of body weight at 150 mg/kg/day.
        5. Teratology - Rats. A developmental study in rats fed dosages of 
    0, 24.4, 146, and 438 mg/kg/day (HDT) resulted in developmental 
    toxicity NOAEL of 438 mg/kg/day and a maternal toxicity NOAEL of 146 
    mg/kg/day based on reduced food consumption, increased water intake, 
    and mortality at 438 mg/kg/day (HDT). Under the conditions of this 
    study, quinclorac did not produce any sign of embryo/fetal toxicity and
    
    [[Page 66537]]
    
    did not alter fetal morphological development.
        6. Teratology - Rabbits. A developmental study in rabbits fed 
    dosages of 0, 70, 200, and 600 mg/kg/day resulted in a developmental 
    toxicity NOAEL of 200 mg/kg/day based on an increase in resorptions and 
    postimplantation loss; a decrease in the number of live fetuses and 
    decreased fetal body weights at the 600 mg/kg/day dose level (HDT). At 
    all other treatment levels no embryo/fetal toxicity was observed. The 
    maternal toxicity NOAEL is 70 mg/kg/day based on decreased body weight 
    gain and food consumption at 200 mg/kg/day; and increased water 
    consumption, increased mortality, and discoloration of the kidney at 
    600 mg/kg/day.
        7. Two-generation reproduction - Rats. A 2-generation reproduction 
    study with rats fed dosages of 0, 50, 200, and 600 mg/kg/day resulted 
    in a reproductive NOAEL of 200 mg/kg/day based on reduced pup viability 
    and pup weight, and delay in development (pinna unfolding and eye 
    opening) at 600 mg/kg/day with a maternal NOAEL of 200 mg/kg/day based 
    on reduced body weights at 600 mg/kg/day. At treatment levels of 50 and 
    200 mg/kg/day no substance related finding were noted either in the 
    parent animals or the offspring.
        8. Mutagenicity. All Salmonella Assays testing the appropriate 
    technical 3,7-dichloro-8-quinoline carboxylic acid were negative. The 
    3,7-dichloro-8-quinoline carboxylic acid was negative in the in vivo 
    cytogenetics (Chinese hamster) at dose levels ranging from 2,000 to 
    8,000 mg/kg and did not induce unscheduled DNA synthesis in the UDS 
    assay at levels ranging from 101 to 1,520 -ug/ml.
        9. Metabolism - Rat. A metabolism study with rats receiving dosages 
    of 15, 100, 600 and 1,200 mg/kg/day resulted in more than 90% of the 
    administered radioactivity eliminated in the urine within 5 days (most 
    within 24 hours) and 0.7 - 3.7% in the feces. Radioactivity was mainly 
    associated with the unchanged parent compound. The glucuronic acid 
    conjugate of quinclorac was a minor (2 - 5%) metabolite in urine.
        10. Reference dose. The established Reference Dose (RfD) for 
    quinclorac is based on the 2-year feeding study in mice with a 
    threshold NOAEL of 37.5 mg/kg/day. Using an uncertainty factor of 100, 
    the RfD has been calculated to be 0.38 mg/kg/day.
        11. Cancer classification and risk assessment. The cancer 
    classification of quinclorac has been reviewed by the FIFRA Scientific 
    Advisory Panel (SAP). The Panel recommended that the compound be 
    classified as a Group D carcinogen (not classifiable as to human 
    carcinogenicity). The EPA Health Effects Peer Review Committee (PRC) 
    evaluated the carcinogenic potential of quinclorac and the conclusions 
    of the SAP and has classified quinclorac as a Group D carcinogen. Since 
    quinclorac is not classified as a carcinogen, a cancer risk assessment 
    was not necessary for approval of the currently established tolerances. 
    Therefore, a cancer risk assessment for the proposed tolerances on 
    wheat and sorghum is also not necessary.
        12. In addition to the data described above, BASF is submitting a 
    21 day dermal study in the rat to supplement the quinclorac toxicology 
    database. Results indicate that the NOAEL for quinclorac in this study 
    is greater than 1,000 mg/kg body weight.
    
    C. Aggregate Exposure / Cumulative Effects
    
        1. Chronic dietary exposure. BASF has estimated aggregate dietary 
    exposure based on the Theoretical Maximum Residue Contribution (TMRC) 
    calculation. The TMRC is a ``worst case'' estimate of dietary exposure 
    since it is assumed that 100% of all crops for which tolerances are 
    established are treated and that residues are at the tolerances level. 
    Since the proposed label prohibits use in many wheat and sorghum 
    producing states, the TMRC calculation results in a significant 
    overestimate of human dietary exposure.
        The quinclorac TMRC for the overall U.S. population from the 
    currently established rice and animal tolerances is 0.001485 mg/kg bwt/
    day which represents 0.39% of the RfD. A preliminary estimate of 
    dietary exposure to residues of quinclorac from the proposed tolerances 
    in wheat and sorghum increases the TMRC by 0.000836 mg/kg bwt/day and 
    accounts for approximately 0.22% of the RfD for the overall U.S. 
    population.
        2. Acute dietary exposure. BASF has reviewed the toxicity database 
    for quinclorac and has concluded that there is no acute dietary concern 
    since there is no indication of any significant toxicity from a one day 
    or single event oral exposure. The LD50 for technical 
    quinclorac has been determined to be 3,060 mg/kg for males and 2,190 
    mg/kg for females.
        3. Drinking water exposure. Other potential sources of exposure for 
    the general population to residues of quinclorac are residues in 
    drinking water and exposure from non-occupational sources. Based on the 
    available studies used in EPA's assessment of environmental risk, BASF 
    does not anticipate exposure to residues of quinclorac in drinking 
    water. There is no established Maximum Concentration Level (MCL) for 
    residues of quinclorac in drinking water under the Safe Drinking Water 
    Act (SDWA).
        4. Non-occupational exposure. Quinclorac is not currently labeled 
    for any nonagricultural use. An application for use of quinclorac on 
    turfgrass is currently pending. The proposed turf registration 
    restricts use of the product to certified commercial applicators and 
    those under their direct supervision. Use of the product by typical 
    uncertified homeowners will be prohibited. Therefore, potential for 
    non-occupational exposure to the general population is significantly 
    reduced compared to general use turf products. BASF is a member of the 
    industry wide Outdoor Residential Exposure Task Force. The Task Force 
    is currently generating data to assess exposure resulting from the use 
    of turf products.
    
    D. Cumulative Effects
    
        BASF has considered the potential for cumulative effects of 
    quinclorac and other substances that have a common mechanism of 
    toxicity. BASF is not aware of any other EPA registered active 
    ingredient that is structurally similar to quinclorac or has a common 
    mechanism of toxicity.
    
    E. Safety Determination
    
        1. U.S. population. Using the conservative exposure assumptions 
    described above and based on the completeness and the reliability of 
    the toxicity data, BASF has estimated that aggregate exposure to 
    quinclorac will utilize approximately 0.22% of the RfD for the U.S. 
    population. BASF concludes that there is a reasonable certainty that no 
    harm will result from the aggregate exposure to residues of quinclorac, 
    including anticipated dietary exposure and non-occupational exposures.
        2. Infants and children. No signs of teratogenicity were observed 
    in either the rat or rabbit Developmental studies. The NOAEL values 
    from the Developmental studies are significantly higher than the NOAEL 
    from the 2-year feeding study in mice (threshold NOAEL of 37.5 mg/kg/
    day) used to establish the RfD.
        In the Reproductive Toxicity study, Quinclorac elicited signs of 
    embryotoxicity only at dose levels where clear maternal toxicity was 
    observed. Fertility and reproduction parameters were not affected even 
    at the highest treatment levels (1,155 mg/kg/
    
    [[Page 66538]]
    
    day). The NOAEL values from the Reproduction study are significantly 
    higher than the NOAEL from the 2-year feeding study in mice (threshold 
    NOAEL of 37.5 mg/kg/day) used to establish the RfD.
        Based on the demonstrated lack of significant developmental or 
    reproductive toxicity, BASF believes that the RfD used to assess safety 
    to the general population is adequate to assess safety to children. The 
    EPA evaluation of the established rice and animal tolerances concluded 
    that for the subgroup exposed to the highest dietary risk, nonnursing 
    infants less than 1 year old, the TMRC is 0.010065 mg/kg bwt/day or 
    2.65 % of the RfD. The addition of the wheat and sorghum tolerances 
    increases the TMRC for this subgroup to approximately 0.100726 mg/kg 
    bwt/day or 2.82 % of the RfD. BASF concludes that there is a reasonable 
    certainty that no harm will result to infants and children from 
    aggregate exposure to the residues of quinclorac, including all 
    anticipated dietary exposure and all other non-occupational exposures.
    
    F. Endocrine Effects
    
        No specific tests have been conducted with quinclorac to determine 
    whether the chemical may have an endocrine like effect in humans. 
    However, there were no significant findings in other relevant tests 
    (developmental and reproductive toxicity tests) which would suggest 
    that quinclorac produces endocrine like effects.
    
    G. International Tolerances
    
        A maximum residue level has not been established under the Codex 
    Alimentarius Commission for quinclorac in wheat and sorghum. (Joanne I. 
    Miller)
    
    2. Novartis Crop Protection, Inc.
    
    PP 2F4107
    
        EPA has received a pesticide petition (PP 2F4107) from Novartis 
    Crop Protection, Inc., P.O. Box 18300, Greensboro, NC 28479-8300. 
    proposing pursuant to section 408(d) of the Federal Food, Drug, and 
    Cosmetic Act (FFDCA), 21 U.S.C. 346a(d), to amend 40 CFR part 180 by 
    establishing a tolerance for residues of Difenconazole, [(2S,4R)/
    (2R,4S)]/[2R,4R/2S,4S)] 1-(2-4-(4-chlorophenoxy)-2-chlorophenyl]-4-
    methyl-1,3-dioxolan2yl-methyl)-1H-1,2,4-triazole in or on the raw 
    agricultural commodity wheat grain, forage, and straw at 0.1 parts per 
    million (ppm); cattle, eggs, goats, hogs, horses, poultry and sheep 
    0.05; and milk at 0.01 ppm. EPA has determined that the petition 
    contains data or information regarding the elements set forth in 
    section 408(d)(2) of the FFDCA; however, EPA has not fully evaluated 
    the sufficiency of the submitted data at this time or whether the data 
    supports granting of the petition. Additional data may be needed before 
    EPA rules on the petition.
    
    A. Residue Chemistry
    
        1. Plant metabolism. The nature of the residue is adequately 
    understood in plants and animals. The metabolism of difenoconazole has 
    been studied in wheat, tomatoes, potatoes, and grapes. The metabolic 
    pathway was the same in these four separate and distinct crops.
        2. Analytical method. Novartis has submitted a practical analytical 
    method for detecting and measuring levels of difenoconazole in or on 
    food with the limit of quantitation that allows monitoring of food with 
    residues at or above the levels set in the proposed tolerances. EPA 
    will provide information on this method to FDA. The method is available 
    to anyone who is interested in pesticide residue enforcement from the 
    Field Operations Division, Office of Pesticide Programs.
        3. Magnitude of residues. Data has been provided from fourteen 
    spring and winter wheat residue trials conducted in major wheat growing 
    states. Application rates were 24 grams a.i. and 48 grams a.i./100 kg 
    seed (10.9 and 21.8 grams a.i./ 100 lb seed, respectively). A 
    processing study was also conducted in which two foliar applications 
    were made in addition to the seed treatment, in an attempt to generate 
    grain samples containing measurable residues. Bran, middlings, shorts 
    and germ, and patent flour were tested for residues.
        No residues of difenoconazole (<0.1 ppm)="" were="" detected="" in="" wheat="" grain="" or="" in="" any="" of="" the="" processed="" milled="" fractions,="" even="" when="" the="" higher="" seed="" treatment="" rate="" was="" coupled="" with="" two="" foliar="" treatments.="" the="" use="" of="" difenoconazole="" as="" a="" seed="" treatment="" will="" not="" result="" in="" detectable="" residues="" in="" grain="" or="" processed="" commodities.="" similarly,="" no="" residues="" of="" difenoconazole="" (0.05="" ppm)="" were="" detected="" on="" wheat="" forage="" or="" straw.="" no="" food="" additive="" tolerances="" are="" necessary="" for="" grain="" commodities.="" tolerances="" in="" meat,="" milk,="" poultry="" or="" eggs="" were="" established="" for="" enforcement="" purposes.="" b.="" toxicological="" profile="" the="" following="" mammalian="" toxicity="" studies="" were="" conducted="" and="" submitted="" in="" support="" of="" tolerances="" for="" difenoconazole.="" 1.="" acute="" toxicity.="" difenoconazole="" has="" a="" low="" order="" of="" acute="" toxicity.="" the="" oral="" rat="">50 is 1,453 mg/kg. The rabbit acute 
    dermal LD50 is > 2,010 mg/kg and the rat inhalation 
    LC50 is > 3.285 mg/L. It is not a skin sensitizer in guinea 
    pig and shows slight eye and dermal irritation in the rabbit.
        2. Genotoxicty. There was no evidence of the induction of point 
    mutations in an Ames test.
        There was no evidence of mutagenic effects in a mouse lymphoma 
    test.
        There was no evidence of mutagenic effects in a nucleus anomaly 
    test with Chinese hamsters.
        There was no evidence of induction of DNA damage in a rat 
    hepatocyte DNA repair test.
        There was no evidence of induction of DNA damage in a human 
    fibroblast DNA repair test.
        3. Reproductive and developmental toxicity. An oral teratology 
    study in rats had a maternal NOAEL of 16 mg/kg/day based on excess 
    salivation and decreased body weight gain and food consumption. The 
    developmental NOAEL of 85 mg/kg/day was based on effects seen secondary 
    to maternal toxicity including slightly reduced fetal body weight and 
    minor changes in skeletal ossification.
        An oral teratology study in rabbits had maternal NOAEL of 25 mg/kg/
    day based on decreased body weight gain, death, and abortion. The 
    developmental NOAEL of 25 mg/kg/day was based on effects seen secondary 
    to maternal toxicity including slight increase in post-implantation 
    loss and resorptions, and decreased fetal weight.
        A 2-generation reproduction study in rats had a parental and 
    reproductive NOAEL of 25 ppm based on significantly reduced female body 
    weight gain, and reductions in male pup weights at 21 days.
        4. Subchronic toxicity. A 13-week rat feeding study identified 
    liver as a target organ and had a NOAEL of 20 ppm.
        A 13-week mouse feeding study identified liver as a target organ 
    and had a NOAEL of 20 ppm.
        A 26-week dog feeding study identified liver and eye as target 
    organs and had a NOAEL of 100 ppm.
        A 21-day dermal study in rabbits had a NOAEL of 10 mg/mg/day based 
    on decreased body weight gain at 100 and 1,000 mg/kg/day.
        5. Chronic toxicity. A 24-month feeding study in rats had a NOAEL 
    of 20 ppm based on liver toxicity at 500 and 2,500 ppm. There was no 
    evidence of an oncogenic response.
        An 18-month mouse feeding study had an overall NOAEL of 30 ppm 
    based on decreased body weight gain and liver toxicity at 300 ppm. 
    There was an increase in liver tumors only at dose levels that exceeded 
    the maximum
    
    [[Page 66539]]
    
    tolerated dose (MTD). The oncogenic NOAEL was 300 ppm.
        A 12-month feeding study in dogs had a NOAEL of 100 ppm based on 
    decreased food consumption and increased alkaline phosphatase levels at 
    500 ppm.
        6. Carcinogenicity. A 24-month feeding study in rats had a NOAEL of 
    20 ppm based on liver toxicity at 500 and 2,500 ppm. There was no 
    evidence of an oncogenic response.
        An 18-month mouse feeding study had an overall NOAEL of 30 ppm 
    based on decreased body weight gain and liver toxicity at 300 ppm. 
    There was an increase in liver tumors only at dose levels that exceeded 
    the maximum tolerated dose (MTD). The oncogenic NOAEL was 300 ppm.
        7. Animal metabolism. The metabolism of difenoconazole is well 
    understood. Studies with 14C-difenoconazole in the rat, goat, and hen 
    demonstrate that the majority of the administered dose (76 to > 98%) is 
    eliminated via the excreta as parent and metabolites. Very low 
    concentrations of radioactivity, accounting for <1 to="" 4%="" of="" the="" applied="" dose,="" remain="" in="" tissues.="" the="" liver="" and="" kidney="" typically="" show="" the="" highest="" radioactivity,="" but="" in="" the="" rat,="" the="" highest="" concentration="" in="" any="" tissue="" was="" found="" in="" the="" fat.="" concentrations="" in="" goat="" milk="" reached="" a="" plateau="" on="" day="" 6="" of="" the="" study="" at="" 0.043="" ppm="" for="" the="" triazole="" label="" and="" 0.007="" ppm="" for="" the="" phenyl="" label="" when="" goats="" were="" fed="" approximately="" 5="" ppm="" for="" 10="" days.="" similarly,="" very="" little="" radioactivity="" was="" deposited="" in="" eggs;="" radioactivity="" reached="" a="" plateau="" of="" 0.248="" to="" 0.299="" ppm="" in="" yolks="" after="" 7="" to="" 8="" days,="" and="" 0.007="" to="" 0.153="" ppm="" in="" whites="" after="" 5="" days,="" in="" hens="" fed="" at="" a="" rate="" equivalent="" to="" 5="" ppm="" in="" the="" diet="" for="" 14="" consecutive="" days.="" cga-205375,="" an="" alcohol="" resulting="" from="" the="" deskelitalization="" of="" the="" dioxolane="" ring="" of="" difenoconazole,="" is="" a="" major="" metabolite="" found="" in="" animal="" tissues,="" excreta,="" milk,="" and="" eggs.="" the="" presence="" of="" cga-71019,="" containing="" only="" the="" triazole="" ring,="" and="" cga-189138,="" containing="" only="" the="" phenyl="" ring,="" indicates="" that="" bridge="" cleavage="" can="" occur="" in="" animals="" as="" well="" as="" plants.="" the="" metabolite="" patterns="" in="" the="" excreta="" of="" hens,="" goats,="" and="" rats="" were="" similar.="" 8.="" metabolite="" toxicology.="" the="" residue="" of="" concern="" for="" tolerance="" setting="" purposes="" is="" the="" parent="" compound.="" metabolites="" of="" difenoconazole="" are="" considered="" to="" be="" of="" equal="" or="" lesser="" toxicity="" than="" the="" parent.="" 9.="" endocrine="" disruption.="" developmental="" toxicity="" studies="" in="" rats="" and="" rabbits="" and="" a="" two-generation="" reproduction="" study="" in="" rats="" gave="" no="" specific="" indication="" that="" difenoconazole="" may="" have="" effects="" on="" the="" endocrine="" system="" with="" regard="" to="" development="" or="" reproduction.="" furthermore,="" histologic="" investigations="" were="" conducted="" on="" endocrine="" organs="" (thyroid,="" adrenal,="" and="" pituitary,="" as="" well="" as="" endocrine="" sex="" organs)="" from="" long-term="" studies="" in="" dogs,="" rats,="" and="" mice.="" there="" was="" no="" indication="" that="" the="" endocrine="" system="" was="" targeted="" by="" difenoconazole,="" even="" when="" animals="" were="" treated="" with="" maximally="" tolerated="" doses="" over="" the="" majority="" of="" their="" lifetime.="" difenoconazole="" has="" not="" been="" found="" in="" raw="" agricultural="" commodities="" at="" the="" limit="" of="" quantification.="" based="" on="" the="" available="" toxicity="" information="" and="" the="" lack="" of="" detected="" residues,="" it="" is="" concluded="" that="" difenoconazole="" has="" no="" potential="" to="" interfere="" with="" the="" endocrine="" system,="" and="" there="" is="" no="" risk="" of="" endocrine="" disruption="" in="" humans.="" c.="" aggregate="" exposure="" 1.="" dietary="" exposure="" --="" food.="" when="" the="" potential="" dietary="" exposure="" to="" difenoconazole="" from="" established="" and="" pending="" tolerances="" is="" calculated,="" the="" theoretical="" maximum="" residue="" concentration="" (tmrc)="" of="" 0.000473="" mg/kg/="" day="" utilizes="" 4.73%="" of="" the="" rfd="" for="" the="" overall="" u.s.="" population.="" for="" the="" most="" exposed="" population="" subgroups,="" children="" and="" non-nursing="" infants,="" the="" tmrc="" is="" 0.001252="" mg/kg/day,="" utilizing="" 12.52%="" of="" the="" rfd="" followed="" by="" children="" (1-6="" years)="" exposed="" to="" 11.24%="" of="" the="" rfd.="" novartis="" has="" conducted="" another="" exposure="" analysis="" using="" additional="" crops="" and="" similar="" conservative="" assumptions.="" in="" this="" analysis,="" oats,="" barley,="" cotton="" and="" bananas="" (pending="" import="" tolerance)="" were="" included="" in="" addition="" to="" wheat.="" tolerances="" or="" proposed="" tolerances="" were="" 0.1="" ppm="" each="" for="" wheat,="" oats,="" and="" barley,="" and="" 0.2="" ppm="" for="" bananas.="" tolerances="" were="" 0.01="" ppm="" for="" milk="" and="" 0.05="" ppm="" for="" all="" other="" commodities:="" beef,="" goat,="" horse,="" rabbit,="" sheep,="" pork,="" turkey,="" eggs,="" chicken,="" and="" other="" poultry.="" very="" conservative="" assumptions="" were="" used="" to="" estimate="" residues="" (i.e.="" 100%="" of="" all="" wheat,="" oats,="" barley="" and="" imported="" bananas="" used="" for="" human="" consumption="" or="" forage="" was="" treated="" and="" all="" racs="" contained="" tolerance="" level="" residues).="" these="" estimates="" result="" in="" a="" extreme="" overestimate="" of="" human="" dietary="" exposure.="" calculated="" tmrc="" values="" from="" these="" assumptions="" utilize="" 4.73%="" of="" the="" rfd="" for="" the="" u.s.="" population="" and="" 12.52%="" of="" the="" rfd="" for="" non-nursing="" infants.="" 2.="" drinking="" water.="" other="" potential="" sources="" of="" exposure="" of="" the="" general="" population="" to="" residues="" of="" pesticides="" are="" drinking="" water="" and="" non-occupational="" sources.="" difenoconazole="" is="" currently="" used="" as="" a="" seed="" treatment="" and="" residues="" are,="" therefore,="" incorporated="" into="" the="" soil.="" the="" likelihood="" of="" contamination="" of="" surface="" water="" from="" run-off="" is="" essentially="" negligible.="" in="" addition,="" parent="" and="" aged="" leaching,="" soil="" adsorption/desorption,="" and="" radiolabeled="" pipe="" studies="" indicated="" that="" difenoconazole="" has="" a="" low="" potential="" to="" leach="" in="" the="" soil="" and="" it="" would="" not="" be="" expected="" to="" reach="" aquatic="" environments.="" for="" these="" reasons,="" and="" because="" of="" the="" low="" use="" rate,="" exposures="" to="" residues="" in="" ground="" water="" are="" not="" anticipated.="" 3.="" non-dietary="" exposure.="" non-occupational="" exposure="" for="" difenoconazole="" has="" not="" been="" estimated="" since="" the="" current="" registration="" is="" limited="" to="" seed="" treatment.="" therefore,="" the="" potential="" for="" non-="" occupational="" exposure="" to="" the="" general="" population="" is="" insignificant.="" novartis="" has="" considered="" the="" potential="" for="" cumulative="" effects="" of="" difenoconazole="" and="" other="" substances="" of="" common="" mechanism="" of="" toxicity.="" novartis="" has="" concluded="" that="" consideration="" of="" a="" common="" mechanism="" of="" toxicity="" in="" aggregate="" exposure="" assessment="" is="" not="" appropriate="" at="" this="" time.="" novartis="" has="" no="" information="" to="" indicate="" that="" the="" toxic="" effects="" (generalized="" liver="" toxicity)="" seen="" at="" high="" doses="" of="" difenoconazole="" would="" be="" cumulative="" with="" those="" of="" any="" other="" compound.="" thus,="" novartis="" is="" considering="" only="" the="" potential="" risk="" of="" difenoconazole="" from="" dietary="" exposure="" in="" its="" aggregate="" and="" cumulative="" exposure="" assessment.="" d.="" safety="" determination="" 1.="" u.s.="" population.="" non-occupational="" exposure="" for="" difenoconazole="" has="" not="" been="" estimated="" since="" the="" current="" registration="" is="" limited="" to="" seed="" treatment.="" therefore,="" the="" potential="" for="" non-occupational="" exposure="" to="" the="" general="" population="" is="" insignificant.="" novartis="" has="" considered="" the="" potential="" for="" cumulative="" effects="" of="" difenoconazole="" and="" other="" substances="" of="" common="" mechanism="" of="" toxicity.="" novartis="" has="" concluded="" that="" consideration="" of="" a="" common="" mechanism="" of="" toxicity="" in="" aggregate="" exposure="" assessment="" is="" not="" appropriate="" at="" this="" time.="" novartis="" has="" no="" information="" to="" indicate="" that="" the="" toxic="" effects="" (generalized="" liver="" toxicity)="" seen="" at="" high="" doses="" of="" difenoconazole="" would="" be="" cumulative="" with="" those="" of="" any="" other="" compound.="" thus,="" novartis="" is="" considering="" only="" the="" potential="" risk="" of="" difenoconazole="" from="" dietary="" exposure="" in="" its="" aggregate="" and="" cumulative="" exposure="" assessment.="" if="" more="" realistic="" assumptions="" were="" used="" to="" estimate="" anticipated="" residues="" and="" appropriate="" market="" share,="" this="" percentage="" would="" be="" considerably="" lower,="" and="" would="" be="" significantly="" lower="" than="" 100%,="" even="" for="" the="" highest="" exposed="" population="" subgroup.="" epa="" generally="" has="" no="" concern="" for="" exposures="" below="" 100%="" [[page="" 66540]]="" of="" the="" rfd.="" therefore,="" novartis="" concludes="" that="" there="" is="" reasonable="" certainty="" that="" no="" harm="" will="" result="" from="" daily="" aggregate="" exposure="" to="" residues="" of="" difenoconazole="" over="" a="" lifetime.="" 2.="" infants="" and="" children.="" developmental="" toxicity="" and="" two-generation="" toxicity="" studies="" were="" evaluated="" to="" determine="" if="" there="" is="" a="" special="" concern="" for="" the="" safety="" of="" infants="" and="" children="" from="" exposure="" to="" residues="" of="" difenoconazole.="" there="" was="" no="" evidence="" of="" embryo="" toxicity="" or="" teratogenicity,="" and="" no="" effects="" on="" reproductive="" parameters,="" including="" number="" of="" live="" births,="" birth="" weights,="" and="" post-natal="" development,="" at="" dose="" levels="" that="" did="" not="" cause="" significant="" maternal="" toxicity.="" in="" addition,="" there="" were="" no="" effects="" in="" young="" post-weaning="" animals="" that="" were="" not="" seen="" in="" adult="" animals="" in="" the="" 2-generation="" reproduction="" study.="" therefore,="" novartis="" concludes="" that="" it="" is="" inappropriate="" to="" assume="" that="" infants="" and="" children="" are="" more="" sensitive="" than="" the="" general="" population="" to="" effects="" from="" exposure="" to="" residues="" of="" difenoconazole.="" e.="" international="" tolerances="" there="" are="" no="" codex="" maximum="" levels="" established="" for="" residues="" of="" difenoconazole.="" (cynthia="" giles-parker)="" fr="" doc.="" 98-31683="" filed="" 12-1-98;="" 8:45="" am="" billing="" code="" 6560-50-f="">

Document Information

Published:
12/02/1998
Department:
Environmental Protection Agency
Entry Type:
Notice
Action:
Notice.
Document Number:
98-31683
Dates:
Comments, identified by the docket control number PF-847, must be received on or before January 4, 1999.
Pages:
66535-66540 (6 pages)
Docket Numbers:
PF-847, FRL-6043-2
PDF File:
98-31683.pdf