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    PESTICIDE RESIDUES IN FOOD - 1981


    Sponsored jointly by FAO and WHO






    EVALUATIONS 1981







    Food and Agriculture Organization of the United Nations
    Rome

    FAO PLANT PRODUCTION AND PROTECTION PAPER 42

    pesticide residues in food:
    1981 evaluations

     the monographs

    data and recommendations
    of the joint meeting
    of the
    FAO panel of experts on pesticide residues
    in food and the environment
    and the
    WHO expert group on pesticide residues

    Geneva, 23 November-2 December 1981

    FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
    Rome 1982

    CHLOROTHALONIL

    Explanation

         Chlorothalonil was evaluated in 1974, 1977, 1978 and 1979.* After
    receiving data on toxicological studies, performed under a variety of
    experimental conditions on several animal species, a temporary ADI of
    0.03 mg/kg bw was established.

         In order to answer the still open questions pertaining to the
    safety evaluation of chlorothalonil, the 1979 Meeting required
    that studies be conducted to define the growth reduction after
    administration of the parent compound or its major metabolite,
    4-hydroxy-2,5,6-trichloroisophthalonitrile, in pups relative to
    ingestion or secretion into milk.

         Furthermore, it was considered desirable that additional
    information be provided comprising: 1) the elucidation of
    discrepancies in the carcinogenicity studies; 2) observations on
    occupationally exposed humans, and 3) the extent of metabolism of
    chlorothalonil in mammals.

         New material dealing with some of the subject areas enumerated
    was submitted. No data on the metabolism of chlorothalonil were
    received. The Meeting was, however, informed that investigations are
    currently under way to study the metabolic profile (e.g, biliary,
    faecal and urinary metabolites, tissue residues) in mice, rats and
    dogs. The results of these studies are expected to be submitted for
    consideration at a later date.

         Temporary maximum residue limit recommendations on a variety of 
    commodities were made on the basis of previous evaluations. The 1979
    Meeting concluded that further information in several areas was either
    required by 1981 or considered desirable. Of those studies considered
    desirable were (1) experimental information on the possible occurrence
    of hexachlorobenzene residues on crops requiring multiple treatments,
    and (2) results of ongoing studies on the effects of cooking under
    closed conditions on residue levels and chemical composition. This
    monograph addendum reviews data submitted on these two items, as well
    as some additional information on residues and national use patterns
    and tolerances.

              

    *    See Annex II for FAO and WHO documentation.

    DATA FOR THE ESTIMATION OF ACCEPTABLE DAILY INTAKE

    TOXICOLOGICAL STUDIES

    Special studies to define growth reduction after administration of
    4-hydroxy-2,5,6,trichloroisophthalonitrile (DS-3701)

    Rat

         A metabolite of chlorothalonil, DS-3701, was investigated in a
    3-generation/reproduction study in Sprague-Dawley derived (CD) rats.
    The test compound was given continuously in the diet beginning at age
    43 days of the F0 generation, at levels of 10, 60 and 125 ppm. An
    additional group received the same diet (Purina Laboratory Chow),
    however, without the test compound.

         Each of the 3 generations, consisting of 4 groups of 15 male and
    30 female rats, was mated twice, the first time at the age of at least
    142 days (F0) or 121 days (F1 and F2), and the second time after a
    rest period of at least 14 days following the weaning of the first
    litter.

         Body weight, physical condition, food consumption, data on the
    reproductive cycles (e.g. pregnancy rate, fertility indices, viability
    and survival of offspring, mating, littering and mortality) were
    monitored.

         The experiments were terminated by killing the survivors with
    ether (parents after weaning the second litter; offspring not selected
    as parents for the next generation at age 21 days). A post-mortem
    examination was performed.

         Apart from the significant reduction in body weight at the 60 and
    125 ppm levels, no substance-related changes could be observed. It
    should, however, be noted that during the entire study selected organs
    of only 5 animals were histopathologically examined. Interpretation of
    ocular lesions (e.g. keratitis, corneal ulcers, iritis and pitted
    corneas), frequently encountered, particularly in treated animals of
    the F1 generation, is difficult. These lesions may, however, be due
    to the apparent infection of the test animals, both control and
    treated, with sialodacryoadenitis (SDA) virus.

         In these studies, a no-effect level of 10 ppm could be
    established.

    OBSERVATIONS ON OCCUPATIONALLY EXPOSED HUMANS

    Dermatological observations

         Among the 191 participants in an annual medical screening of
    employees of a chlorothalonil manufacturing plant, 2 persons were
    found with dermatological symptoms. The relevance of the changes to
    occupational exposure was questionable (Diamond Shamrock 1980).

         In a manufacturing plant, of the 103 employees working directly
    with chlorothalonil 60.2% showed some type of skin abnormality,
    including 19 cases of so-called Daconil (chlorothalonil) contact
    dermatitis.

         Of the 45 employees not working with chlorothalonil, 18.5% showed
    skin disorders including 2 cases of Daconil contact dermatitis. As a
    consequence of improved industrial hygiene, a year later the rate of
    skin abnormalities considerably decreased (to 21.1% and 16%
    respectively). No Daconil contact dermatitis was found (Diamond
    Shamrock 1980).

    Inhalation and dermal exposure of applicators to chlorothalonil and
    hexachlorobenzene(HCB)

         Eleven workers, normally engaged in mixing, loading or
    application of pesticides in the field, participated in a study
    monitoring the level of inhalation and dermal exposure to and urinary
    excretion of chlorothalonil. As commercial preparations contain some
    HCB (in the present study < 0.02%), the measurement of this
    contaminant was also included.

         Under the conditions specified in the label directions, the
    effect of aerial and ground application, at both maximum and common
    rate of use, was studied.

         The highest single dermal exposure was measured on hands
    (1.7 mg/m2/h); the dermal LD50 for rabbits is 10 g/kg bw. The
    highest single inhalation exposure, expressed as a percentage of the
    LC50 for rats, was 1%. The majority of the individual data were less
    than one-tenth of that.

         It was therefore concluded that, on the basis of exposure levels
    measured, dermal and inhalation exposure to chlorothalonil constitutes
    a very low hazard to agricultural applicators. The level of exposure
    to HCB was below the sensitivity of the analytical method used
    (Diamond Shamrock 1980).

    RESIDUES IN FOOD

    USE PATTERN

    United States

         Current registered USA uses for formulations (or similar ones)
    utilized on commodities for which field trials were conducted in this
    monograph are given in Table 1.

        TABLE 1.  Uses registered in USA for chlorothalonil
                                                                                               

                                              Application rate
                                                                    
    Formulation         Commodity      kg a.i./ha        at intervals           Pre-harvest
                                                         (days)                 Interval (days)
                                                                                               

    BRAVONIL 500        celery         0.84-1.23         (3-5)                  7
    and BRAVO W-75                     1.7 -2.52         (7)                    7

                        cucumber       1.7 -2.52         (7)                    none

                        potato         0.84-1.23         (7-10)                 none

                        snap beans     2.6                                      7

                        tomato         1.23-2.52         (7-14)                 none

    BRAVO 500           soybean        0.87-2.07         (2 applications)       6 weeks
                                       1.6               (3 applications)
                                                         (14)
                                                                                               
    
    Netherlands

         Present uses of chlorothalonil in The Netherlands are summarized
    in Table 2.

    RESIDUES RESULTING FROM SUPERVISED TRIALS

         Field trials were conducted in Europe and the United States on a
    variety of selected commodities to develop data to answer questions
    concerning possible residues of hexachlorobenzene (HCB) resulting from
    multiple applications of chlorothalonil under a variety of conditions
    and using various modes of application.

        TABLE 2.  Uses for chlorothalonil in the Netherlands
                                                                                                                                              

    Crop or        Kind of pest          Extent of use/    Application rate                  Treatment               Pre-harvest   In use
    Situation      controlled            economic          kg a.i./ha         Formulation    first                   interval      since
                                         importance        (g/100 l)          w.p.25% +      treatment               (days)
                                                                                                                                              

    Potato         Phytophthora          small scale       1.5-2.2            75% w.p.       repeated                              1966
    Potato         Phytophthora          moderate          0.75-1.0           w.p.25% +      treatments                            1976
                                                                              50% maneb      "

    Mushroom       Verticillium sp.      small scale       2.25 g/m2          75% w.p.       first treatment         5             1977
                                                                                             after covering.
                                                                                             repeat two weeks
                                                                                             later after first
                                                                                             harvest

    Mushroom       green mildew                            1.15 g/m2          75% w.p.       Spray immediately       5             1978
                                                           (115)                             after 1st and 2nd
                                                                                             harvest.

    Gherkin        Mycosphaerella                          (150)              75% w.p.       Spray repeatedly        3             1979
                   and                                                                                                             (cucumber)
    Cucumber       downy mildew                                                                                                    1977
    Melon
    Leek           Phytophthora                            (150)              75% w.p.       spray every 10-14       14            1979
                   porri and                                                                 days
    Celeriac       Puccinia allii
                   Septoria apiicola                       1.9                75% w.p.       spray every 10-14       28            1979
    Blanched                                                                                 days
    celery

    Onion          Botrytis squamosa                       1.5                75% w.p.       spray from beginning    28            1979
    Shallot                                                (1.5)                             of June, repeat
                                                                                             every 7-10 days
                                                                                                                                              

    TABLE 2.  (con't)
                                                                                                                                              

    Crop or        Kind of pest          Extent of use/    Application rate                  Treatment               Pre-harvest   In use
    Situation      controlled            economic          kg a.i./ha         Formulation    first                   interval      since
                                         importance        (g/100 l)          w.p.25% +      treatment               (days)
                                                                                                                                              

    Onion          Botrytis squamosa     small scale       0.5                w.p. 25%       "                       28            1979
    Shallot                                                (0.5)              + 50% maneb                                          (Onion 1976)
                   powdery mildew        moderate          1.2                w.p. 20% +     1 treatment,

    Wheat          ripening                                (1.2)              40% sulphur    repeat once, if         42
                   diseases                                                   + 20% maneb    necessary, just
                                                                                             before blossoming
    Tomato         Botrytis                                (150)                             spray repeatedly        3
                   Septoria apiicola
                   Phytophthora
    Courgettes     Mycosphaerella                          (150)
    (zucchini)     downy mildew                                                                                      3
    Strawberry                                                                                                       14
    (under                                                                                                           (alternate)
    consideration)
                                                                                                                                              

    Other uses: in floriculture and against blue staining of wood.
             The commodities chosen were selected to represent commodities for
    which there are Codex temporary maximum residue limits (MRLs) or
    established national tolerances. The formulations used were Bravo 500
    (a water dispersible flowable formulation containing 500 g of
    chlorothalonil per 1) and Bravo W-75, (a wettable powder formulation
    containing 75% chlorothalonil). Two batches of Bravo 500 and Bravo
    W-75 were used and contained maximum levels of 0.02% HCB and 0.62%
    PCBN and 0.04% HCB and 0.82% PCBN, respectively, as impurities.

         As carrot and celery samples from Florida have reportedly
    contained residues of pentachlorobenzonitrile (PCBN), and as it has
    been implied that these reported residues may have been associated
    with applications of chlorothalonil (Barry et al 1977), samples were
    also analysed for PCBN. Residues of chlorothalonil were also
    determined, but 4-hydroxy-2,5,6-trichloro-1,3-benzenedicarbonitrile
    (which is included in the Codex temporary MRLs) was not.

         Residues for chlorothalonil, HCB and PCBN resulting from up to 15
    applications during field trials on eight commodities, representing
    approximately 40 studies and over 600 samples analysed, are summarized
    in Table 3 (United States studies) and Table 4 (European studies).

         In addition to the studies provided to answer questions on
    possible residue of HCB, information is also provided from residue
    trials in The Netherlands in Table 5.

    Celery

         After up to 15 broadcast treatments with Bravo 500 or Bravo W-75
    at the maximum recommended active label rate of 2.5 kg/ha by boom
    sprayer, maximum residues on unwashed celery were 13.7 mg/kg
    chlorothalonil, and 0.157 mg/kg PCBN on day of last application.
    Maximum residues of HCB were 0.009 mg/kg. After seven days (interval
    used as a basis for Codex temporary MRLs), maximum residues on
    unwashed celery were 3.8 mg/kg chlorothalonil, 0.003 mg/kg HCB and
    0.062 mg/kg PCBN. Residues at day of application were even less when
    washed according to commercial practices. However, inconsistent or no
    reduction could be observed for chlorothalonil after a seven-day
    interval and residues were too low to make an assessment for HCB
    residues.

         Maximum apparent residues after seven days on untreated, unwashed
    samples were 0.05, < 0.003 and 0.008 mg/kg for chlorothalonil, HCB
    and PCBN, respectively.

         When treated with the above two formulations according to the
    given rates and conditions, and analysed after a seven-day interval
    from last application, residues of chlorothalonil alone were well
    below the temporary MRL of 15 mg/kg. Maximum residues of HCB are

        TABLE 3.

    Summary of results from United States field residue studies to determine the
    presence and amounts of chlorothalonil (2,4,5,6-tetrachloroisophthalonitrile), HCB (hexachlorobenzene)
    and PCBN (pentachlorobenzonitrile) in various crops treated with chlorothalonil products.
                                                                                                                                                

                                                     RATE
                                                                 
                                             FORMULA-               NUMBER OF   TREATMENT                   RESIDUES (PPM)1
                                             TION AND               APPLICA-    TO                                                   
    CROP                  PRODUCT  APPLICA-  [SPRAY     ACTIVE      TIONS,      HARVEST     CHLOROTHALONIL     HCB          PCBN        NUMBER
    AND         LOCATION  FORMU-   TION      VOLUME     INGREDIENT  TABLE IN    INTERVAL           HIGH           HIGH           HIGH   SAMPLES
    REFERENCE*  AND YEAR  LATION   METHOD    (L/HA)]**  (KG/HA)     REPORT      (DAYS)      MEAN   VALUE   MEAN   VALUE   MEAN   VALUE  ANALYZED
                                                                                                                                                

    Celery3     Florida   Bravo    Boom      3.36         2.5       15             0        11.75  13.72   0.004  0.009   0.138  0.157  6
    (1)         1979      W-75     Sprayer   kg/ha                  Table 4        7        1.44   1.64    ND     0.003   0.054  0.062  6
                                   (broad-   [374                   samples       14        2.94   3.76    ND     ND      0.044  0.057  6
                                   cast)     l/ha]                  unwashed

                                                                    15             0        0.96   1.23    ND     ND      0.034  0.049  6
                                                                    Table 5        7        2.19   2.99    ND     ND      0.027  0.035  6
                                                                    samples       14        1.33   1.61    ND     ND      0.021  0.027  6
                                                                    washed

                          Bravo    Boom      4.97 l/ha    2.5       15             0        3.15   4.16    ND     0.003   0.057  0.079  6
                          500      Sprayerl  [374                   Table 6        7        0.29   0.37    ND     ND      0.027  0.036  6
                                   (broad-   l/ha]                  samples       14        0.92   1.44    ND     ND      0.025  0.030  6
                                   cast)                            unwashed

                                                                    15             0        0.66   0.99    ND     ND      0.020  0.030  6
                                                                    Table 7        7        0.62   0.80    ND     ND      0.014  0.022  6
                                                                    samples       14        0.43   0.51    ND     ND      0.010  0.014  6
                                                                    washed
                                                                                                                                                

    TABLE 3 (con't)
                                                                                                                                                

                                                     RATE
                                                                 
                                             FORMULA-               NUMBER OF   TREATMENT                   RESIDUES (PPM)1
                                             TION AND               APPLICA-    TO                                                   
    CROP                  PRODUCT  APPLICA-  [SPRAY     ACTIVE      TIONS,      HARVEST     CHLOROTHALONIL     HCB          PCBN        NUMBER
    AND         LOCATION  FORMU-   TION      VOLUME     INGREDIENT  TABLE IN    INTERVAL           HIGH           HIGH           HIGH   SAMPLES
    REFERENCE*  AND YEAR  LATION   METHOD    (L/HA)]**  (KG/HA)     REPORT      (DAYS)      MEAN   VALUE   MEAN   VALUE   MEAN   VALUE  ANALYZED
                                                                                                                                                

    Celery                UN-      --        --          --         Table 8        0        0.33   0.42    ND     ND      0.009  0.013  6
    (1)                   TREATED                                   samples        7        0.02   0.05    ND     ND      0.005  0.008  6
    (con't)                                                         unwashed      14        0.04   0.06    ND     ND      ND     0.005  6

                                                                    Table 9        0        0.03   0.07    ND     ND      ND     0.012  6
                                                                    samples        7        0.03   0.04    ND     ND      ND     ND     6
                                                                    washed        14        0.04   0.05    ND     ND      ND     ND     6

    Cucumber    Florida   Bravo    Boom      4.97 l/ha    2.5       7              0        0.18   0.33    ND     ND      ND     0.006  6
    (2)         1979      500      Sprayer   [374                   Table 4        7        0.02   0.02    ND     ND      ND     ND     6
                                             l/ha]                                14        ND     ND      ND     ND      ND     ND     6

                                                                    7              0        0.10   0.18    ND     ND      ND     0.005  6
                                                                    Table 5        7        0.01   0.01    ND     ND      ND     ND     6
                                                                                  14        ND     0.01    ND     ND      ND     ND     6

                          Bravo    Boom      3.36         2.5       7              0        0.86   1.09    ND     ND      ND     0.006  6
                          W-75     Sprayer   kg/ha                  Table 6        7        0.02   0.03    ND     ND      ND     ND     6
                                             [374                                 14        0.01   0.01    ND     ND      ND     ND     6
                                             l/ha]

                          UN-      --        --           --        0              0        0.01   0.03    ND     ND      ND     ND     3
                          TREATED                                   Table 7        7        ND     0.01    ND     ND      ND     ND     3
                                                                                  14        ND     ND      ND     ND      ND     ND     3
                                                                                                                                                

    TABLE 3 (con't)
                                                                                                                                                

                                                     RATE
                                                                 
                                             FORMULA-               NUMBER OF   TREATMENT                   RESIDUES (PPM)1
                                             TION AND               APPLICA-    TO                                                   
    CROP                  PRODUCT  APPLICA-  [SPRAY     ACTIVE      TIONS,      HARVEST     CHLOROTHALONIL     HCB          PCBN        NUMBER
    AND         LOCATION  FORMU-   TION      VOLUME     INGREDIENT  TABLE IN    INTERVAL           HIGH           HIGH           HIGH   SAMPLES
    REFERENCE*  AND YEAR  LATION   METHOD    (L/HA)]**  (KG/HA)     REPORT      (DAYS)      MEAN   VALUE   MEAN   VALUE   MEAN   VALUE  ANALYZED
                                                                                                                                                

    Cucumber              Bravo    Boom      4.97 l/ha    2.5       7              0        0.86   1.20    ND     ND      0.021  0.028  6
    (2)                   500      Sprayer   [374                   Table 8        7        0.46   0.63    ND     0.004   0.006  0.010  6
    (con't)                                  l/ha]                                14        0.12   0.18    ND     ND      ND     0.005  6

                                                                    7              0        0.84   1.43    ND     ND      0.018  0.027  6
                                                                    Table 9        7        0.32   0.53    ND     0.005   0.007  0.014  6
                                                                                  14        0.06   0.11    ND     ND      ND     0.007  6

                          Bravo    Boom      3.36         2.5       7              0        0.57   0.75    ND     0.003   0.011  0.016  6
                          W-75     Sprayer   kg/ha                  Table 10       7        0.37   0.57    ND     0.003   ND     0.008  6
                                             [374                                 14        0.12   0.18    ND     ND      ND     0.007  6
                                             l/ha]

                          UN-      --        --           --        Table 11       0        0.02   0.03    ND     ND      ND     ND     3
                          TREATED                                                  7        0.02   0.04    ND     0.003   ND     ND     3
                                                                                  14        ND     0.01    ND     ND      ND     ND     3

                Ohio      Bravo    Pressu-   4.97 l/ha    2.5       8              0        0.25   0.50    ND     ND      0.012  0.013  6
                1979      500      rized     [1402                  Table 12       7        0.12   0.14    ND     ND      ND     0.007  6
                                   Hand      l/ha]                                14        0.12   0.19    ND     ND      ND     0.006  6
                                   Sprayer                          8              0        0.33   0.60    ND     ND      0.008  0.013  6
                                                                    Table 13       7        0.19   0.34    ND     ND      ND     ND     6
                                                                                  14        0.10   0.11    ND     ND      ND     0.006  6
                                                                                                                                                

    TABLE 3 (con't)
                                                                                                                                                

                                                     RATE
                                                                 
                                             FORMULA-               NUMBER OF   TREATMENT                   RESIDUES (PPM)1
                                             TION AND               APPLICA-    TO                                                   
    CROP                  PRODUCT  APPLICA-  [SPRAY     ACTIVE      TIONS,      HARVEST     CHLOROTHALONIL     HCB          PCBN        NUMBER
    AND         LOCATION  FORMU-   TION      VOLUME     INGREDIENT  TABLE IN    INTERVAL           HIGH           HIGH           HIGH   SAMPLES
    REFERENCE*  AND YEAR  LATION   METHOD    (L/HA)]**  (KG/HA)     REPORT      (DAYS)      MEAN   VALUE   MEAN   VALUE   MEAN   VALUE  ANALYZED
                                                                                                                                                

    Cucumber              Bravo    Pressu-   3.36         2.5       8              0        0.23   0.44    ND     ND      ND     0.012  6
    (2)                   W-75     rized     kg/ha                  Table 14       7        0.14   0.27    ND     ND      ND     0.008  6
    (con't)                        Hand      [1423                                14        0.07   0.08    ND     ND      ND     0.005  6
                                   Sprayer   l/ha

                          UN-      --        --           --        Table 15       0        0.04   0.06    ND     ND      ND     ND     3
                          TREATED                                                  7        0.01   0.02    ND     ND      ND     ND     3
                                                                                  14        ND     ND      ND     ND      ND     ND     3

    (3)         Michigan  Bravo    Sprink-   2.63         1.32      6              0        0.06   0.09    ND     ND      ND     ND     6
                1979      500      ler       l/ha2                  Table 4        7        0.05   0.07    ND     0.005   ND     ND     6
                                   Irriga-   [NA]
                                   tion

                          UN-      --        --           --        Table 5       --        0.01   0.02    ND     ND      ND     ND     4
                          TREATED

    Oranges     Florida   Bravo    Mist      5.85 l/ha    2.93      1            208        ND     ND      ND     ND      0.010  0.014  4
    (4)         1979      500      Blower    [2339                  Table 5
                                             l/ha]
                                             5.85 l/ha    2.93      1            208        ND     ND      iND    ND      0.013  0.013  4
                                             [4677
                                             l/ha]
                                                                                                                                                

    TABLE 3 (con't)
                                                                                                                                                

                                                     RATE
                                                                 
                                             FORMULA-               NUMBER OF   TREATMENT                   RESIDUES (PPM)1
                                             TION AND               APPLICA-    TO                                                   
    CROP                  PRODUCT  APPLICA-  [SPRAY     ACTIVE      TIONS,      HARVEST     CHLOROTHALONIL     HCB          PCBN        NUMBER
    AND         LOCATION  FORMU-   TION      VOLUME     INGREDIENT  TABLE IN    INTERVAL           HIGH           HIGH           HIGH   SAMPLES
    REFERENCE*  AND YEAR  LATION   METHOD    (L/HA)]**  (KG/HA)     REPORT      (DAYS)      MEAN   VALUE   MEAN   VALUE   MEAN   VALUE  ANALYZED
                                                                                                                                                

    Oranges                                  8.19 l/ha    4.10      1            208        ND     ND      ND     ND      0.013  0.017  4
    (4)                                      [2337
    (con't)                                  l/ha]
                                             8.19 l/ha    4.10      1            208        ND     ND      ND     ND      0.015  0.02   4
                                             [4677
                                             l/ha]

                          UN-      --        --          --         --            --        ND     ND      ND     ND      0.013  0.014  3
                          TREATED

                          Bravo    Mist      5.85 l/ha    2.93      1            221        ND     ND      0.001  0.003   0.011  0.013  4
                          500      Blower    [2339                  Table 6
                                             l/ha]
                                             5.85 l/ha    2.93      1            221        ND     NO      ND     ND      0.014  0.015  4
                                             [4676
                                             l/ha]
                                             8.19 l/ha    4.10      1            221        ND     ND      ND     ND      0.014  0.015  4
                                             [2339
                                             l/ha]
                                             8.19 l/ha    4.10      1            221        ND     ND      ND     ND      0.014  0.015  4
                                             [4676
                                             l/ha]

                          UN-      --        --          --         --            --        ND     ND      ND     ND      0.013  0.014  3
                          TREATED
                                                                                                                                                

    TABLE 3 (con't)
                                                                                                                                                

                                                     RATE
                                                                 
                                             FORMULA-               NUMBER OF   TREATMENT                   RESIDUES (PPM)1
                                             TION AND               APPLICA-    TO                                                   
    CROP                  PRODUCT  APPLICA-  [SPRAY     ACTIVE      TIONS,      HARVEST     CHLOROTHALONIL     HCB          PCBN        NUMBER
    AND         LOCATION  FORMU-   TION      VOLUME     INGREDIENT  TABLE IN    INTERVAL           HIGH           HIGH           HIGH   SAMPLES
    REFERENCE*  AND YEAR  LATION   METHOD    (L/HA)]**  (KG/HA)     REPORT      (DAYS)      MEAN   VALUE   MEAN   VALUE   MEAN   VALUE  ANALYZED
                                                                                                                                                

    Oranges               Bravo    Mist      5.85 l/ha    2.93      1            217        ND     ND      ND     ND      0.016  0.021  4
    (4)                   500      Blower    [2339                  Table 7
    (con't)                                  l/ha]
                                             5.85 l/ha    2.93      1            217        ND     ND      ND     ND      0.018  0.022  4
                                             [4676
                                             l/ha]
                                             8.19 l/ha    4.10      1            217        ND     ND      ND     ND      0.017  0.020  4
                                             [2339
                                             l/ha]
                                             8.19 l/ha    4.10      1            217        ND     ND      ND     ND      0.017  0.021  4
                                             [4676
                                             l/ha]

                          UN-      --        --           --        --            --        ND     ND      ND     ND      0.017  0.019  3
                          TREATED

    Potatoes    Florida   Bravo    Boom      2.49 l/ha    1.25      9              0        0.09   0.11    ND     0.004   ND     ND     6
    (5)         1979      500      Sprayer   [468                   Table 4
                                             l/ha]
                                                                    9              0        0.08   0.11    ND     ND      ND     0.008  6
                                                                    Table 5

                          Bravo    Boom      1.68         1.25      9              0        0.12   0.18    ND     0.003   ND     ND     6
                          W-75     Sprayer   kg/ha                  Table 6
                                             [468
                                             l/ha]
                                                                                                                                                

    TABLE 3 (con't)
                                                                                                                                                

                                                     RATE
                                                                 
                                             FORMULA-               NUMBER OF   TREATMENT                   RESIDUES (PPM)1
                                             TION AND               APPLICA-    TO                                                   
    CROP                  PRODUCT  APPLICA-  [SPRAY     ACTIVE      TIONS,      HARVEST     CHLOROTHALONIL     HCB          PCBN        NUMBER
    AND         LOCATION  FORMU-   TION      VOLUME     INGREDIENT  TABLE IN    INTERVAL           HIGH           HIGH           HIGH   SAMPLES
    REFERENCE*  AND YEAR  LATION   METHOD    (L/HA)]**  (KG/HA)     REPORT      (DAYS)      MEAN   VALUE   MEAN   VALUE   MEAN   VALUE  ANALYZED
                                                                                                                                                

    Potatoes              UN-      --        --          --         Table 13      --        0.01   0.2     ND     ND      ND     ND     2
    (5)                   TREATED
    (con't)

                          Bravo    Boom      2.49 l/ha    1.25      11             0        0.05   0.07    ND     0.004   ND     0.008  6
                          500      Sprayer   [374                   Table 7
                                             l/ha]

                                                                    11             0        0.04   0.06    ND     0.003   ND     0.006  6
                                                                    Table 8

                          Bravo              1.68         1.25      11             0        0.06   0.13    ND     ND      ND     0.008  6
                          W-75               kg/ha                  Table 9
                                             [374
                                             l/ha]

                          UN-      --        --           --        Table 13      --        0.01   0.02    ND     ND      ND     ND     6
                          TREATED

                Idaho     Bravo    NA2       2.49 l/ha    1.25      2              0        0.02   0.02    ND     ND      ND     ND     6
                1979      500                NA2                    Table 10

                          UN-      --        --           --        Table 13      --        0.01   0.02    ND     ND      ND     ND     6
                          TREATED
                                                                                                                                                

    TABLE 3 (con't)
                                                                                                                                                

                                                     RATE
                                                                 
                                             FORMULA-               NUMBER OF   TREATMENT                   RESIDUES (PPM)1
                                             TION AND               APPLICA-    TO                                                   
    CROP                  PRODUCT  APPLICA-  [SPRAY     ACTIVE      TIONS,      HARVEST     CHLOROTHALONIL     HCB          PCBN        NUMBER
    AND         LOCATION  FORMU-   TION      VOLUME     INGREDIENT  TABLE IN    INTERVAL           HIGH           HIGH           HIGH   SAMPLES
    REFERENCE*  AND YEAR  LATION   METHOD    (L/HA)]**  (KG/HA)     REPORT      (DAYS)      MEAN   VALUE   MEAN   VALUE   MEAN   VALUE  ANALYZED
                                                                                                                                                

    Potatoes    New York  Bravo    8-row     2.49 l/ha    1.25      9              0        0.01   0.01    ND     ND      ND     ND     6
    (5)         1979      500      Boom      [824                   Table 11
    (con't)                        Sprayer   l/ha]

                          Bravo    8-row     1.68         1.25      9              0        0.01   0.02    ND     ND      ND     ND     6
                          W-75     Boom      kg/ha                  Table 12
                                   Sprayer

                          UN-      --        --           --        Table 13      --        0.01   0.02    ND     ND      ND     ND     6
                          TREATED

    Snapbeans   Ohio      Bravo    Pressu-   4.97 l/A     2.50      2              0        2.56   3.55    ND     0.003   0.056  0.077  6
    (6)         1979      500      rized                            Table 5        7        1.16   1.29    ND     ND      0.024  0.025  6
                                   Hand      [935                                 14        0.24   0.46    ND     ND      0.006  0.027  6
                                   Sprayer   l/ha]                  2              0        1.81   3.65    ND     0.003   0.044  0.073  6
                                                                    Table 6        7        1.10   1.32    ND     ND      0.021  0.024  6
                                                                                  14        0.67   0.98    ND     ND      0.018  0.028  6

                          Bravo    Pressu-   3.36         2.50      2              0        2.44   2.87    ND     ND      0.038  0.041  6
                          W-75     rized     kg/ha                  Table 7        7        1.67   1.99    ND     ND      0.034  0.042  6
                                   Hand      [935                                 14        0.49   0.59    ND     ND      ND     0.016  6
                                   Sprayer   l/ha]

                          UN-      --        --           --        Table 4        0        0.12   0.13    ND     ND      ND     ND     3
                          TREATED                                                  7        0.01   0.02    ND     0.003   ND     ND     3
                                                                                  14        0.01   0.01    ND     ND      ND     ND     3
                                                                                                                                                

    TABLE 3 (con't)
                                                                                                                                                

                                                     RATE
                                                                 
                                             FORMULA-               NUMBER OF   TREATMENT                   RESIDUES (PPM)1
                                             TION AND               APPLICA-    TO                                                   
    CROP                  PRODUCT  APPLICA-  [SPRAY     ACTIVE      TIONS,      HARVEST     CHLOROTHALONIL     HCB          PCBN        NUMBER
    AND         LOCATION  FORMU-   TION      VOLUME     INGREDIENT  TABLE IN    INTERVAL           HIGH           HIGH           HIGH   SAMPLES
    REFERENCE*  AND YEAR  LATION   METHOD    (L/HA)]**  (KG/HA)     REPORT      (DAYS)      MEAN   VALUE   MEAN   VALUE   MEAN   VALUE  ANALYZED
                                                                                                                                                

    Snapbeans   Florida   Bravo    Pressu-   3.36         2.50      7              0        0.89   1.35    ND     ND      0.024  0.038  6
    (6)         1979      W-75     rized     kg/ha                  Table 11       7        0.49   0.61    ND     ND      0.012  0.016  6
    (con't)                        Hand      [468                                 14        0.17   0.21    ND     ND      ND     ND     6
                                   Sprayer   l/ha]
                                   over row

                          Bravo    Pressu-   4.97 l/A     2.50      7              0        0.85   1.03    ND     ND      0.030  0.039  6
                          500      rized     [468                   Table 9        7        0.33   0.39    ND     ND      ND     0.012  6
                                   Hand      l/ha]                                14        0.09   0.10    ND     ND      ND     ND     6
                                   Sprayer                          7              0        0.68   0.89    ND     ND      0.020  0.030  6
                                   Over                             Table 10       7        0.40   0.60    ND     ND      0.015  0.017  6
                                   Row                                            14        0.07   0.11    ND     ND      ND     ND     6

                          UN-      --        --           --        Table 8        0        0.01   0.01    ND     ND      ND     0.005  3
                          TREATED                                                  7        0.02   0.04    ND     ND      ND     ND     3
                                                                                  14        ND     ND      ND     ND      ND     ND     3

                          Bravo    Boom      4.97 l/ha    2.50      7              0        0.11   0.11    ND     ND      0.018  0.024  2
                          500      Sprayer   [374                   Table 13       7        0.14   0.16    ND     ND      0.007  0.013  2
                                             l/ha]                                14        0.04   0.05    ND     ND      ND     0.008  2

                                                                    7              0        1.77   1.80    ND     ND      0.010  0.02   2
                                                                    Table 14       7        0.13   0.15    ND     ND      ND     ND     2
                                                                                  14        0.05   0.05    0.007  0.014   ND     ND     2
                                                                                                                                                

    TABLE 3 (con't)
                                                                                                                                                

                                                     RATE
                                                                 
                                             FORMULA-               NUMBER OF   TREATMENT                   RESIDUES (PPM)1
                                             TION AND               APPLICA-    TO                                                   
    CROP                  PRODUCT  APPLICA-  [SPRAY     ACTIVE      TIONS,      HARVEST     CHLOROTHALONIL     HCB          PCBN        NUMBER
    AND         LOCATION  FORMU-   TION      VOLUME     INGREDIENT  TABLE IN    INTERVAL           HIGH           HIGH           HIGH   SAMPLES
    REFERENCE*  AND YEAR  LATION   METHOD    (L/HA)]**  (KG/HA)     REPORT      (DAYS)      MEAN   VALUE   MEAN   VALUE   MEAN   VALUE  ANALYZED
                                                                                                                                                

    Snapbeans             Bravo    Boom      3.36         2.50      7              0        0.08   0.11    ND     ND      0.015  0.021  2
    (6)                   W-75     Sprayer   kg/ha                  Table 15       7        0.53   0.57    ND     ND      ND     ND     2
    (con't)                                  [374                                 14        0.22   0.24    ND     ND      0.006  0.011  2
                                             l/ha]

                          UN-      --        --           --        Table 12       0        0.02   0.02    ND     ND      ND     ND     2
                          TREATED                                                  7        ND     ND      ND     ND      ND     ND     2
                                                                                  14        0.01   0.01    ND     ND      ND     ND     2

                New York  Bravo    Commer-   4.97 l/ha    2.5       4              0        2.40   3.50    ND     ND      0.038  0.048  6
                1979      500      cial      [412                   Table 17       7        2.07   3.04    ND     ND      0.036  0.042  6
                                   Boom      l/ha]                                14        1.26   1.88    ND     ND      0.034  0.038  6
                                   Sprayer

                          UN-      --        --           --        Table 16       0        0.01   0.01    ND     ND      ND     ND     3
                          TREATED                                                  7        ND     ND      ND     ND      ND     ND     3
                                                                                  14        ND     ND      ND     ND      ND     ND     3

    Soybeans    Kentucky  Bravo    Pressu-   2.34 l/ha    1.17      2             57        ND     0.013   ND     ND      0.009  0.010  6
    (7)         (1979)    500      rized     [430                   Table 5
                                   Sprayer   l/ha]

                          UN-      --        --           --        --            --        ND     ND      ND     ND      0.010  0.017  6
                          TREATED
                                                                                                                                                

    TABLE 3 (con't)
                                                                                                                                                

                                                     RATE
                                                                 
                                             FORMULA-               NUMBER OF   TREATMENT                   RESIDUES (PPM)1
                                             TION AND               APPLICA-    TO                                                   
    CROP                  PRODUCT  APPLICA-  [SPRAY     ACTIVE      TIONS,      HARVEST     CHLOROTHALONIL     HCB          PCBN        NUMBER
    AND         LOCATION  FORMU-   TION      VOLUME     INGREDIENT  TABLE IN    INTERVAL           HIGH           HIGH           HIGH   SAMPLES
    REFERENCE*  AND YEAR  LATION   METHOD    (L/HA)]**  (KG/HA)     REPORT      (DAYS)      MEAN   VALUE   MEAN   VALUE   MEAN   VALUE  ANALYZED
                                                                                                                                                

    Soybeans    Missouri  Bravo    aerial    12.34        1.17      2             45        0.013  0.017   0.005  0.006   0.005  0.008  6
    (7)         1979      500                l/ha NA2               Table 6
    (con't)

                          UN-      --        --           --        --            --        0.019  0.039   0.004  0.006   0.009  0.013  6
                          TREATED

                                   NA2       2.34 l/ha    1.17      2             47        ND     0.010   ND     ND      ND     0.007  6
                                             [187                   Table 7
                                             l/ha]

                          UN-      --        --           --        --            --        ND     0.010   ND     0.003   ND     0.008  6
                          TREATED

                Ohio      Bravo    Pressu-   4.09 l/ha    2.05      2             54        0.013  0.019   ND     ND      0.015  0.016  6
                1979      500      rized     [468                   Table 8       54        0.015  0.018   ND     ND      0.013  0.014  6
                                   Hand      l/ha]
                                   Sprayer

                          UN-      --        --           --        --            --        ND     ND      ND     ND      0.016  0.023  6
                          TREATED

                Florida   Bravo    Boom      3.36         2.50      2             43        ND     ND      ND     ND      0.016  0.021  6
                1979      W-75     Sprayer   kg/ha                  Table 9
                                             [374
                                             l/ha]
                                                                                                                                                

    TABLE 3 (con't)
                                                                                                                                                

                                                     RATE
                                                                 
                                             FORMULA-               NUMBER OF   TREATMENT                   RESIDUES (PPM)1
                                             TION AND               APPLICA-    TO                                                   
    CROP                  PRODUCT  APPLICA-  [SPRAY     ACTIVE      TIONS,      HARVEST     CHLOROTHALONIL     HCB          PCBN        NUMBER
    AND         LOCATION  FORMU-   TION      VOLUME     INGREDIENT  TABLE IN    INTERVAL           HIGH           HIGH           HIGH   SAMPLES
    REFERENCE*  AND YEAR  LATION   METHOD    (L/HA)]**  (KG/HA)     REPORT      (DAYS)      MEAN   VALUE   MEAN   VALUE   MEAN   VALUE  ANALYZED
                                                                                                                                                

    Soybeans              Bravo    Boom      4.97 l/ha    2.50      2             43        ND     ND      ND     ND      0.020  0.024  6
    (7)                   500      Sprayer   [374                                           ND     ND      ND     ND      0.018  0.020  6
    (con't)                                  l/ha]

                          UN-      --        --           --        --            --        ND     ND      ND     ND      0.19   0.024  6
                          TREATED

                Texas     Bravo    Backpack  4.09 l/ha    2.05      2             40        ND     ND      ND     ND      0.008  0.008  8
                1979      500      Mist      [187                   Table 10
                                   blower    l/ha]

                          UN-      --        --           --        --            --        ND     0.014   ND     ND      0.008  0.008  6
                          TREATED

    Tomatoes    Ohio      Bravo    Pressu-   4.97 l/ha    2.5       8              0        0.72   1.14    ND     0.004   0.027  0.034  9
    (8)         1979      500      rized     [935                   Table 4        7        0.70   1.08    ND     0.003   0.028  0.043  9
                                   Hand      l/ha]                                14        0.62   1.18    ND     ND      0.014  0.021  9
                                   Sprayer                          8              0        0.95   2.68    ND     ND      0.039  0.062  9
                                                                    Table 5        7        0.77   1.09    ND     ND      0.025  0.039  9
                                                                                  14        0.40   0.59    ND     ND      0.016  0.022  9

                          Bravo    Pressu-   3.36         2.5       8              0        0.70   0.91    ND     ND      0.025  0.031  9
                          W-75     rized     kg/ha                  Table 6        7        0.37   0.60    ND     ND      0.026  0.042  9
                                   Hand      [935                                 14        0.37   0.57    ND     ND      0.013  0.017  9
                                   Sprayer   l/ha]
                                                                                                                                                

    TABLE 3 (con't)
                                                                                                                                                

                                                     RATE
                                                                 
                                             FORMULA-               NUMBER OF   TREATMENT                   RESIDUES (PPM)1
                                             TION AND               APPLICA-    TO                                                   
    CROP                  PRODUCT  APPLICA-  [SPRAY     ACTIVE      TIONS,      HARVEST     CHLOROTHALONIL     HCB          PCBN        NUMBER
    AND         LOCATION  FORMU-   TION      VOLUME     INGREDIENT  TABLE IN    INTERVAL           HIGH           HIGH           HIGH   SAMPLES
    REFERENCE*  AND YEAR  LATION   METHOD    (L/HA)]**  (KG/HA)     REPORT      (DAYS)      MEAN   VALUE   MEAN   VALUE   MEAN   VALUE  ANALYZED
                                                                                                                                                

    Tomatoes              UN-      --        --           --        Table 7        0        ND     0.01    ND     ND      0.011  0.015  6
    (8)                   TREATED                                                  7        ND     0.01    ND     ND      0.022  0.027  6
    (con't)                                                                       14        ND     ND      ND     ND      0.010  0.019  6

                Florida   Bravo    Boom      4.97 l/ha    2.5       11             0        0.62   1.21    ND     0.003   0.035  0.044  9
                          500      Sprayer   [374                   Table 8        7        0.14   0.39    ND     ND      0.025  0.030  9
                                             l/ha]                                14        0.03   0.05    ND     0.008   0.024  0.030  9

                                                                    11             0        0.42   0.67    ND     ND      0.036  0.078  9
                                                                    Table 9        7        0.11   0.25    ND     ND      0.033  0.040  9
                                                                                  14        0.04   0.18    ND     ND      0.027  0.038  9

                          Bravo    Boom      3.36         2.5       11             0        1.16   2.73    ND     ND      0.036  0.053  9
                          W-75     Sprayer   kg/ha                  Table 10       7        0.16   0.34    ND     ND      0.021  0.030  9
                                             [374                                 14        0.08   0.14    ND     ND      0.029  0.034  6
                                             l/ha]

                          UN-      --        --           --        Table 11       0        ND     0.72    ND     ND      0.022  0.028  6
                          TREATED                                                  7        ND     ND      ND     ND      0.024  0.029  6
                                                                                  14        ND     ND      ND     ND      0.027  0.031  6

                Indiana   Bravo    Boom      4.97 l/ha    2.5       6              0        3.54   5.28    ND     0.004   0.074  0.117  9
                1979      500      Sprayer   [702                   Table 12       7        2.18   2.98    ND     ND      0.040  0.057  9
                                             l/ha]                                14        1.36   2.45    ND     ND      0.042  0.056  9
                                                                                                                                                

    TABLE 3 (con't)
                                                                                                                                                

                                                     RATE
                                                                 
                                             FORMULA-               NUMBER OF   TREATMENT                   RESIDUES (PPM)1
                                             TION AND               APPLICA-    TO                                                   
    CROP                  PRODUCT  APPLICA-  [SPRAY     ACTIVE      TIONS,      HARVEST     CHLOROTHALONIL     HCB          PCBN        NUMBER
    AND         LOCATION  FORMU-   TION      VOLUME     INGREDIENT  TABLE IN    INTERVAL           HIGH           HIGH           HIGH   SAMPLES
    REFERENCE*  AND YEAR  LATION   METHOD    (L/HA)]**  (KG/HA)     REPORT      (DAYS)      MEAN   VALUE   MEAN   VALUE   MEAN   VALUE  ANALYZED
                                                                                                                                                

    Tomatoes              Bravo    Boom      3.36         2.5       6              0        1.34   3.76    ND     ND      0.032  0.053  9
    (8)                   W-75     Sprayer   kg/ha                  Table 13       7        0.45   1.46    ND     ND      0.018  0.025  9
    (con't)                                  [702                                 14        0.09   0.43    ND     ND      0.021  0.026  9
                                             l/ha]

                          UN-      --        --           --        Table 14       0        ND     ND      ND     ND      0.014  0.016  6
                          TREATED                                                  7        0.09   0.30    ND     ND      0.021  0.027  6
                                                                                  14        ND     ND      ND     ND      0.023  0.028  6

                Virginia  Bravo    Pressu-   4.97 l/ha    2.5       5              0        2.61   5.98    ND     ND      0.046  0.070  9
                1979      500      rized     [468                   Table 15       7        0.91   1.56    ND     ND      0.017  0.029  9
                                   Backpack  l/ha]                                14        0.40   1.19    ND     ND      0.009  0.024  9

                          UN-      --        --           --        Table 16       0        ND     ND      ND     ND      0.014  0.020  6
                          TREATED                                                  7        ND     ND      ND     ND      0.019  0.021  6
                                                                                  14        ND     ND      ND     ND      0.006  0.011  6

                Florida   Bravo    Pressu-   4.97 l/ha    2.5       10             0        0.83   1.30    ND     ND      0.012  0.017  3
                1979      500      rized     [935                   Table 17
                                   Hand      l/ha]
                                   Sprayer

                          UN-      --        --           --        Table 18       0        ND     ND      ND     ND      0.008  0.009  3
                          TREATED
                                                                                                                                                

    TABLE 3 (con't)
                                                                                                                                                

                                                     RATE
                                                                 
                                             FORMULA-               NUMBER OF   TREATMENT                   RESIDUES (PPM)1
                                             TION AND               APPLICA-    TO                                                   
    CROP                  PRODUCT  APPLICA-  [SPRAY     ACTIVE      TIONS,      HARVEST     CHLOROTHALONIL     HCB          PCBN        NUMBER
    AND         LOCATION  FORMU-   TION      VOLUME     INGREDIENT  TABLE IN    INTERVAL           HIGH           HIGH           HIGH   SAMPLES
    REFERENCE*  AND YEAR  LATION   METHOD    (L/HA)]**  (KG/HA)     REPORT      (DAYS)      MEAN   VALUE   MEAN   VALUE   MEAN   VALUE  ANALYZED
                                                                                                                                                

    Tomatoes    Michigan  Bravo    Sprink-   3.51 l/ha    1.75      10             0        2.13   3.06    ND     ND      0.037  0.046  6
    (9)         1979      500      ler       [8418                  Tables         7        1.65   2.18    ND     ND      0.031  0.041  6
    (con't)                        Irriga-   l/ha]                  1, 2 & 3      14        1.12   1.58    ND     ND      0.028  0.035  6
                                   tion

                          UN-      --        --           --        Tables         0        ND     ND      ND     ND      ND     0.011  6
                          TREATED                                   1, 2 & 3       7        0.06   0.19    ND     ND      0.011  0.022  6
                                                                                  14        0.03   0.17    ND     ND      0.013  0.016  6
                                                                                                                                                

    *   See numbered references under Diamond Shamrock, 1981c.
    **  Spray volume in brackets.

    1  ND = Not detectable: <0.01 ppm chlorothalonil; <0.003 ppm HCB; <0.005 ppm PCBN.

    2  NA = Not available.

    3  field trimmed to 14 inches according to good agricultural practice.

    TABLE 4  SUMMARY OF RESIDUES OF CHLOROTHALONIL AND HCB FROM EUROPEAN FIELD TRALS
                                                                                                                                                

                                                                                 RESIDUES IN MG/KG
                                            APPLICATION                                                                   
                                                                  NUMBER    DAYS AFTER   CHLOROTHALONIL         HCB          REPORT
    CROP      COUNTRY      YEAR   NO.   KG A.I./HA   FORMULATON   SAMPLES   TREATMENT    TREATED  CONTROL  TREATED  CONTROL  NUMBER   REFERENCE2
                                                                                                                                                

    Potatoes  Belgium      1980    6    (1 × 1.5     Bravo 500      11         7           0.01    <0.01   <0.004   <0.004   81/014     (3)
                                         +
                                         2 × 1.9                    11        14          <0.01    <0.01   <0.004   <0.004   81/014     (3)
                                         +
                                         3 × 2.3)                   11        29          <0.01    <0.01   <0.004   <0.004   81/014     (3)

              Netherlands  1980    5    (1 × 1.5     Bravo 500      1         14          <0.01    <0.01   <0.003   <0.003   81/044     (3)
                                        +                           1         28          <0.01    <0.01   <0.003   <0.003   81/044     (3)
                                        2 × 1.6                     1         41          <0.01    <0.01   <0.003   <0.003   81/044     (3)
                                        +
                                        2 × 1.8)

              Sweden       1980    5    (2 × 1.1     Bravo 500      1         35           0.03    <0.01   <0.004   <0.004   81/023     (3)
                                        +                           1         42           0.01    <0.01   <0.004   <0.004   81/025     (3)
                                        3 × 1.5)                    1         60          <0..01   <0.01   <0.004   <0.004   81/021     (3)
                                                                    1         67           0.02    <0.01   <0.004   <0.004   81/027     (3)

    Tomatoes  W. Germany   1980   10    (2 × 1.4     Bravo 500      1          0           7.5      0.34    0.003   <0.003)  81/042     (2)
                                        +                           1          2           4.7      - -     0.003   - -      81/042     (2)
                                        8 × 1.8)                    1          3           4.4      0.03    0.003   <0.003   81/042     (2)
                                                                    1          4           4.4      - -     0.003   - -      81/042     (2)
                                                                    1          6           2.4      0.05    0.003   <0.003   81/042     (2)

              Netherlands  1980   10    (2 × 1.35    Bravo 500      1          0           1.6     <0.01   <0.003   <0.003   81/043     (2)
                                        +                           1          1           2.1      0.01   <0.003   <0.003   81/043     (2)
                                        8 × 1.8)                    1          2           2.6      0.01   <0.003   <0.003   81/043     (2)
                                                                    1          4           1.8      0.02   <0.003   <0.003   81/043     (2)
                                                                    1          7           2.4      0.01   <0.003   <0.003   81/043     (2)
                                                                                                                                                

    TABLE 4  (con't)
                                                                                                                                                

                                                                                 RESIDUES IN MG/KG
                                            APPLICATION                                                                   
                                                                  NUMBER    DAYS AFTER   CHLOROTHALONIL         HCB          REPORT
    CROP      COUNTRY      YEAR   NO.   KG A.I./HA   FORMULATON   SAMPLES   TREATMENT    TREATED  CONTROL  TREATED  CONTROL  NUMBER   REFERENCE2
                                                                                                                                                

    Summer    Germany      1980
    Wheat
    grain                          1    1.1          Bravo 500      i         60          <0.01    <0.01   <0.003   <0.003   81/041     (1)
                                   1    1.1          Bravo 500      1         66          <0.01    <0.01   <0.003   <0.003   81/040     (1)

    straw                          1    1.1          Bravo 500      1         60          <0.01    <0.01   <0.003   <0.003   81/041     (1)
                                   1    1.1          Bravo 500      1         66          <0.01    <0.01   <0.003   <0.003   81/040     (1)

              Netherlands  1980
    grain                          1    1.0          Bravo 500      1         68          <0.01    <0.01   <0.004   <0.004   81/035     (1)

    green                          1    1.0          Bravo 500      1          0          14.8      0.28   <0.01    <0.01    81/035     (1)
    ears                                                            1          7           1.9      0.10   <0.01    <0.01    81/035     (1)
                                                                    1         24           0.27     0.09   <0.01    <0.01    81/035     (1)
                                                                    1         35           0.38     0.07   <0.01    <0.01    81/035     (1)

    Winter    Sweden       1980    1    1            Bravo 500F     1         81          <0.01    <0.01   <0.003   <0.003   81/036     (1)
    Wheat                          1    1.25         Bravo 500F     1         81          <0.01     - -    <0.003    - -     81/036     (1)
                                   1    1            Bravo 500F     1         76          <0.01    <0.01   <0.003   <0.003   81/037     (1)
                                   1    1.25         Bravo 500F     1         76          <0.01     - -    <0.003    - -     81/037     (1)
                                   1    1            Bravo 500F     1         64          <0.01    <0.01   <0.003   <0.003   81/038     (1)
                                   1    1.25         Bravo 500F     1         64          <0.01     - -    <0.003    - -     81/038     (1)
                                   1    1            Bravo 500F     1         68          <0.01    <0.01   <0.003   <0.003   81/039     (1)
                                   1    1.25         Bravo 500F     1         68          <0.01     - -    <0.003    - -     81/039     (1)
                                   1    1            Bravo 500F     1         70          <0.01    <0.01   <0.004   <0.004   81/029     (1)
                                   1    1.25         Bravo 500F     1         70          <0.01     - -    <0.004    - -     81/029     (1)
                                                                                                                                                

    1  4 replications, 1 sample, analyzed in duplicate; given residues are averages of duplicates.

    2  See numbered items under Diamond Shamrock, 1981d.

    TABLE 5.  Residues of chlorothalonil resulting from supervised trials in the Netherlands
                                                                                                                                            

    Crop or        Year of         Application                                   Residues in mg/kg, at intervals                    Ref.**
    situation      trial                                                         (days) after (last) application*
                             Number       Rate per                                                                               
                             of           treatment     Formulation    untreated      14              21              28
                             treatments   kg a.i./ha
                                                                                                                                            

    leaves                                                             0.12                                           1.8             1
    celeriac       1976      3            1.83          73%            (0.11-0.13)                                    (1.10-2.28)

    blanched                                                           0.11                                           2.2
    celery         1977      2            1.83          73%            (0.06-0.16)                                    (1.47-2.77)     2

    leek (white)                                                       0.02           0.01            0.11            <0.01
          part                                                         (<0.01-0.12)   (<0.01-0.02)    (0.07-0.16)     (n.d.-0.02)     3
    "  (green)     1978                   1.75          73%            0.26           0.81            2.67            0.37
    "  part                                                                           (0.51-1.05)     (1.25.-4.28     (0.35-0.38)
    "  (total)                                                         0.09           0.28            0.94            0.13
                                                                                      (0.18-0.36)     (0.46-1.50)     (0.13-0.14)

    leek (white)                                                                      0.06            0.03            <0.01
          part                                                                        (0.03-0.10)     (0.02-0.04)     (n.d.-0.01)
    " (green)      1978                   2.25          73%                           5.93            4.22            0.42            3
        part                                                                          (3.02-786)      (3.50-4.85)     (0.07-0.64)
    "   (total)                                                                       2.02            1.42            0.14
                                                                                      (1.05-2.64)     (1.20-1.63)     (0.03-0.21)

    leek (white)                                                                      0.02            0.02            0.04
          part                                                                        (0.01-0.03)     (0.01-0.02)     (n.d.-0.10)
    " (green)      1978                   1.75          73%                           2.63            1.73            1.44            3
    part                                                                              (0.91-3.73)     (0.73-2.44)     (0.67-2.48)
                                                                                      0.91            0.59            0.51
    " (total)                                                                         (0.32-1.26)     (0.25-0.83)     (0.22-0.89)
                                                                                                                                            

    TABLE 5.  (con't)
                                                                                                                                            

    Crop or        Year of         Application                                   Residues in mg/kg, at intervals                    Ref.**
    situation      trial                                                         (days) after (last) application*
                             Number       Rate per                                                                               
                             of           treatment     Formulation    untreated      14              21              28
                             treatments   kg a.i./ha
                                                                                                                                            

                                                                                      10 days         16 days

    strawberry     1980      4            1.5            50%                          6.27            1.36            0.17            4
                                          (+ 0.5         (+ 16,7%                     (4.83-7.08)     (0.84-1.83)
                                          vinchlozolin)  vinchlozolin)                3 samples       3 samples
                                                                                                                                            

    *   Except for strawberries the number of samples was not provided, only the summary data in this table.
    **  References: see Netherlands, 1981.
        generally expected to be less (only one of 36 treated was 0.003 mg/kg)
    than the 0.003 mg/kg limit of determination and residues of PCBN may
    be up to 0.06 mg/kg.

         Chlorothalonil residues on celery from trials in The Netherlands
    were well below the 15 mg/kg limit.

    Cucumber

         Maximum residues on or after the last day of up to eight
    applications of Bravo 500 or Bravo W-75 at 2.5 kg a.i./ha, by three
    modes of application were 1.43 mg/kg chlorothalonil, 0.005 mg/kg HCB
    and 0.028 mg/kg PCBN. Maximum apparent residues on controls were
    0.003 mg/kg HCB, 0.006 mg/kg chlorothalonil and 0.005 mg/kg PCBN.
    Residues on day of last application (or later if residues are higher)
    are the most pertinent to the one day after last application basis for
    the current Codex 5 mg/kg temporary MRL.

         These studies indicate that residues of chlorothalonil alone
    resulting from the given rates (at or 0.7x the recommended rates on
    celery for W-75 and Bravo 500, respectively) and modes of application
    are well within the Codex temporary limit of 5 mg/kg. Residues of
    PCBN may approach 0.03 mg/kg on occasion from these agricultural
    practices. Residues of HCB were at or above the 0.003 mg/kg limit of
    determination on only 4% of the 174 treated samples analysed (2.3%
    were above). Residues in individual samples may occasionally be up to
    0.005 mg/kg.

    Leek

         Summary data for chlorothalonil residue trials in The Netherlands
    were provided. However, whether the applications represented good
    agricultural practices in The Netherlands could not be determined
    since the application rates used were in different units than the good
    agricultural practice information provided. Neither the number of
    applications nor the number of samples was provided. Maximum residues
    at the 14-day PHI were 2.6 mg/kg. Because only summary data were
    provided and other necessary information was lacking, a maximum limit
    could not be estimated for leek.

    Orange

         When immature Valencia oranges were treated once in Florida by
    mist blower, according to proposed uses at 2.93 to 4.1 kg a.i./ha with
    Bravo 500, and harvested at normal harvest, maximum residues were
    <0.01 mg/kg chlorothalonil, 0.003 mg/kg HCB and 0.021 mg/kg PCBN.
    Only one of 44 samples (2%) gave higher HCB residues than those
    found in untreated samples, and even that level was at the limit of
    determination. The chlorothalonil residues are well below the Codex
    temporary MRL of 5 mg/kg. Maximum apparent residues in controls were
    <0.01 mg/kg chlorothalonil, < 0.003 mg/kg HCB and 0.019 mg/kg PCBN.

         Sample analysis was performed after surface extraction, and this
    approach was compared with maceration. As residues were mostly below
    the sensitivity of this method, this comparison at best showed higher
    background with maceration than with surface extraction. There were no
    data on possible concentrations resulting from processing.

    Potato

         Studies were conducted in three states in the U.S.A. and in
    three countries in Europe with up to nine applications at rates up to
    2.3 kg a.i./ha. Samples were taken from zero to 67 days after last
    treatment.

         Maximum residues from the given conditions were 0.18 mg/kg
    chlorothalonil, 0.004 mg/kg HCB and 0.008 mg/kg PCBN. When corrected
    for controls, the 0.18 mg/kg value was said to be 0.1 mg/kg, which is
    the Codex temporary MRL for potatoes. The Codex limit is based on the
    interval between day of last application and harvest. Maximum apparent
    residues in field trial controls were 0.02 mg/kg chlorothalonil,
    <0.003 mg/kg HCB and <0.005 mg/kg PCBN.

         Of the 54 analyses of U.S.A. samples harvested on day of last
    application, four (7%) had HCB residues, > the 0.003 mg/kg limit of
    determination and two (3.7%) were greater. Thus, while for the
    majority of samples there was little difference between treated and
    untreated, measurable residues of HCB and PCBN may occasionally be
    found in individual samples created according to conditions in
    Table 3.

    Snap bean

         Field trials were conducted in three states in the U.S.A. with up
    to seven applications by hand or boom sprayer at proposed use rates of
    2.5 kg a.i./ha as flowable or wettable powder formulation. About 132
    treated samples were analysed from 10 studies.

         Maximum residues were 3.65 mg/kg chlorothalonil, 0.014 mg/kg HCB
    (composite of three replicates) and 0.08 mg/kg PCBN. There is a direct
    correlation between residues of chlorothalonil and those of PCBN.
    Maximum apparent residues in field trial controls were 0.13 mg/kg
    chlorothalonil, 0.003 mg/kg HCB and 0.005 mg/kg PCBN.

         After seven days from last application (the interval basis for
    the Codex 5 mg/kg temporary limit) maximum residues were 3.04 mg/kg
    chlorothalonil, 0.014 mg/kg HCB and 0.042 mg/kg PCBN. Only
    three of the 132 treated samples (2.3%) had HCB residues the
    > 0.003 mg/kg limit of determination and only the 0.014 mg/kg value
    was greater.

         Residues of chlorothalonil per se are therefore less than the
    5 mg/kg Codex limit. Finite residues of PCBN can be expected up to
    approximately 0.04 mg/kg from the given conditions of use and although
    HCB residues are not normally greater on treated than untreated
    samples, residues may occasionally exceed the 0.003 mg/kg limit of
    determination.

    Soybean

         Field trials were conducted with two applications of flowable and
    wettable powder formulations at or approximating proposed rates in six
    geographic areas of the U.S.A., with harvest periods 40 to 57 days
    after the last application. Several modes of application were used.

         Maximum residues resulting from 56 treated samples from the six
    geographical areas were 0.019 mg/kg chlorothalonil, 0.006 mg/kg HCB
    and 0.024 mg/kg PCBN. Maximum field trial control samples were
    0.039 mg/kg chlorothalonil, 0.006 mg/kg HCB and 0.024 mg/kg PCBN.
    There is no significant difference between HCB and PCBN residues from
    treated and untreated samples. Owing to relatively high apparent
    residues in untreated samples, apparent residues above the normal
    limits of determination may be encountered occasionally.

    Strawberry

         A limited amount of data were available for chlorothalonil
    residues on strawberries. While these limited data indicate maximum
    residues of 3-5 mg/kg at a proposed 14-day PHI, no information was
    available on good agricultural practices. Data and information are
    inadequate to estimate maximum residues.

    Tomato

         Field trials were conducted with flowable and wettable powder
    formulations in five states in the U.S.A. and two European countries.
    Up to 11 applications were made with rates up to 2.5 kg a.i./ha, with
    harvests from 0 to 14 days after last application.

         Analyses of 271 treated samples, as well as of untreated samples,
    were made. Residues at day of last application were most comparable to
    the one-day interval basis for the current 5 mg/kg Codex temporary
    limit. Maximum residues on or after last day of application were
    7.5 mg/kg chlorothalonil, 0.008 mg/kg HCB, and 0.117 PCBN. Maximum
    apparent residues on untreated samples were 0.72 mg/kg, <0.003 mg/kg
    and 0.031 mg/kg respectively. Only 10 (3.7%) of treated samples (U.S.
    and European) gave HCB residues > the 0.003 mg/kg limit of
    determination and only two (< 1%) had residues greater.

         Residues of chlorothalonil alone were, for the most part,
    consistent with the 5 mg/kg Codex limit. Even when corrected for
    apparent background residues, a net residue was found for PCBN on all
    treated tomatoes at zero day. Although there is little likelihood of
    HCB residues in tomatoes from the uses and conditions specified,
    residues on individual samples may occasionally exceed the 0.003 mg/kg
    limit of determination.

    Wheat

         Residue studies were conducted in three European countries on
    either summer or winter wheat. One application of 1 to 1.25 kg a.i./ha
    chlorothalonil flowable formulation was made and harvesting done at
    intervals ranging from 0 - 81 days after application.

         Maximum residues on mature grain and straw on treated or
    untreated samples were less than the 0.01 and 0.003 (or 0.004) mg/kg
    limits of determination. The Codex 0.2 mg/kg temporary limit is based
    on a six-week interval from last application to harvest.

         Only "green ears" at 35 days or less after last application
    contained chlorothalonil residue greater than the 0.2 mg/kg Codex
    limit.

    FATE OF RESIDUES

    In storage and processing

         The effects of simmering chlorothalonil in the presence of
    green beans and tomatoes were investigated using open and covered
    vessels (Diamond Shamrock 1981a). Fifty grams of chopped tomatoes or
    green beans in 20 ml of water were fortified with approximately
    1 000 000 dpm of 14C-chlorothalonil and simmered for 10 minutes in
    both covered and uncovered vessels. The labelled chlorothalonil
    fortification solution (10 000 dpm/µl) was prepared from phenyl-
    labelled material of 99.2% purity and with a specific activity of
    4.56 mCi/mmole.

         On cooling, residues were extracted with acidified acetone,
    concentrated, and partitioned with 1:1 petroleum ether: diethyl ether.
    Appropriate aliquots of the organic and aqueous phases were
    quantitated by liquid scintillation counting, including uncooked
    controls, which demonstrated quantitative recoveries by the extraction
    procedures. Results of the simmering studies are summarized in Table 6
    for tomatoes and beans, respectively, for both covered and uncovered
    vessels,

        TABLE 6.  Effect of simmering upon 14C-DS-2787 with tomatoes and green beans1
                                                                                               

                                                     Recovery of 14C-Radioactivity(dpm)
    Simmering           14C-DS.2787                                                            
                        Theoretically       Organic        Aqueous                       Loss
    Condition           Fortified (dpm)     Ogase          Phase          Total          (%)
                                                                                               

    Tomatoes

    Without a           1 000 000           133 000        17 873         150 906        84.5
    pot cover

    With a pot          1 000 000            97 233        15 015         112 248        88.8
    cover
                                                                                               

    Green beans

    Without a           1 000 000            57 900        11 876          69 776        93
    pot cover

    With a pot          1 000 000            95 066        15 120         110 186        89
    cover
                                                                                               

    1  Each recovery and loss is the average of three trials.
    
         These results demonstrate that losses of chlorothalonil under
    these conditions are 85-93% for tomatoes and beans and that there is
    no significant difference in losses between covered or uncovered
    vessels. Losses are apparently a result of volatilization - co-
    distillation.

         Because 14C-residues in the aqueous phase were low (generally
    9-19% of residual activity) these were not characterized. The
    14C-residues in the organic phase were characterized by thin layer
    chromatography and autoradiography. Standards for comparison were
    chlorothalonil (DS-2787), 4-hydroxy-2,5,6-trichloroisophthalonitrile
    (DS-3701) and 3-cyano-2,4,5,6-tetrachlorobenzamide (DS-19221). The
    migration of these standards was determined by UV viewbox.

         Although quantification was not provided, the major residue in
    the pot (in the organic phase) after simmering was said to be DS-2787
    with negligible residues (again unquantified) of DS-3701. Unquantified
    radioactivity near the origin of the thin layer chromatogram was
    thought to be an artifact, as radioactivity was similarly found at the
    origin of the standards and unsimmered control.

    METHODS OF RESIDUE ANALYSIS

         The analytical methods utilized for analysing samples from the
    U.S.A. residue field trials are somewhat similar to methods previously
    described (1974 Evaluations) for chlorothalonil, but modified for
    determination of HCB and PCBN. Little information was provided on the
    analytical methods used for the European studies.

         In general, chopped samples were extracted by tumbling with
    methylene chloride and concentrated. One aliquot was analysed on
    electron capture gas chromatography. Another aliquot was
    chromatographed on a florisil column for separation of HCB and PCBN
    before analysis. In the case of oranges and soybeans, extraction was
    by acetone and acetonitrile, respectively, and partitioning into
    petroleum ether after acidification.

         The methodology was validated on some (but not all) the
    commodities to be as low as 0.02 mg/kg, 0.003 mg/kg and 0.02 mg/kg for
    chlorothalonil, HCB and PCBN respectively. Validations for HCB were
    all > 0.01 mg/kg, except for tomatoes, for which it was validated
    at 0.003 mg/kg. Mean recoveries for all three compounds were generally
    about 70% or better. Recoveries from snap beans and soybeans were
    generally lower than for other commodities.

         The methodology was considered by the manufacturer to be suitable
    for quantitation down to 0.01 mg/kg, 0.003 mg/kg and 0.005 mg/kg
    respectively, for chlorothalonil, HCB and PCBN. While this is
    supported in general, control values are sometimes in excess of these
    values, depending on the commodity.

         The analytical methodologies for The Netherlands residue studies
    were claimed to have a limit of determination of 0.05 mg/kg for
    strawberries and a limit of detection of 0.01 to 0.02 mg/kg for
    celery.

    NATIONAL MAXIMUM RESIDUE LIMITS REPORTED TO THE MEETING

         In addition to national maximum residue limits reported in
    earlier monographs, there are now national MRLs as follows.

    United States

    Commodity                               Tolerances mg/kg*
                                                             

    Onions, dry bulb                               0.5
    Onions, green                                  5
    Papayas                                       15
    Passion fruit                                  3
    Pumpkins                                       5
    Soybeans                                       0.2
                                                             

    *  U.S. tolerances include the metabolite 4-hydroxy-2,5,6-trichloro-
    1,3-benzenedicarbonitrile.

    Netherlands

    Gherkin, celery                                5
    Cucumber, melon                                1
    Bulb, tuber and root vegetables                0.5
    Mushroom                                       0.3
    Wheat                                          0.2
    Potatoes                                       0.05
    Other food commodities                         0.01

    EVALUATION

    COMMENTS AND APPRAISAL

         A three-generation rat study with 4-hydroxy-2,5,6-trichloro-
    isophthalonitrile (a metabolite known to be more acutely toxic than
    chlorothalonil) permitted estimation of a no-effect dietary level of
    10 ppm.

         The extent of conversion of chlorothalonil to the metabolite
    (which is included in the estimated ADI) is not known. In the absence
    of adequate metabolic data, and of a reproduction study permitting
    evaluation, on the parent compound, the Meeting had no alternative
    other than to assume total conversion of chlorothalonil to the
    metabolite. The no-effect level in the rat determined in 1974 was
    therefore reduced.

         Data from field trials designed to answer questions
    on the possible occurrence of hexachlorobenzene (HCB) and
    pentachlorobenzonitrile (PCBN) resulting from the use of wettable
    powder and flowable formulations of chlorothalonil on a variety of
    commodities have been evaluated. Also examined was a study designed to
    answer questions on the nature and levels of residues resulting from

    cooking of commodities containing chlorothalonil and additional
    residue data and information on national tolerances and good
    agricultural practices.

         Field trials were conducted in the United States and European
    countries on a variety of commodities treated at proposed rates with
    flowable and wettable powder chlorothalonil formulations containing
    measured amounts of HCB and PCBN impurities. The studies represented a
    wide geographical distribution and utilized over six methods for up to
    15 applications of formulation, depending on the commodity. More than
    600 samples were analysed from over 40 studies.

         At application rates used and at intervals after harvest
    consistent with those used as a basis for current Codex temporary
    limits (or under proposed use conditions), residues of chlorothalonil
    per se are generally consistent with current Codex limits,
    although analyses were not made for 4-hydroxy-2,5,6-trichloro-1,
    3-benzenedicarbonitrile. This metabolite is included in the current
    Codex temporary limits.

         Under these same conditions of use and intervals following
    application, low levels of PCBN residues did occur and were generally
    correlated with the chlorothalonil residues. Maximum residues may
    occur up to 0.08 mg/kg but are generally half of this or less on most
    commodities. For most treated samples, residues of HCB were not
    significantly different than those on untreated samples. However,
    occasional residues (approximately 1-4%, depending on the commodity)
    may be higher than the 0.003 mg/kg limit of determination of the
    analytical procedure. Only in rare cases is the residue likely to
    reach or exceed 0.01 mg/kg. Although the possibility of chlorothalonil
    or its major metabolite occurring in some animal feed items (silage
    and tomato pomace) has been considered previously, these items
    apparently were not examined for possible residues of HCB or PCBN.
    Also, it seems that dairy cattle tissue or milk samples were not
    analysed for HCB or PCBN when feeding studies were conducted. The
    potential for bio-accumulation of HCB and PCBN in animals from the use
    of chlorothalonil apparently has not been addressed. Although levels
    of these chemicals especially HCB, were shown to be relatively low on
    the eight raw commodities examined, there is some possibility of bio-
    accumulation, especially where crops are treated with chlorothalonil
    in the same fields for several years or where processed products are
    used as animal feeds.

         Analytical methods used in the field trials were considered by
    the manufacturer to be suitable for quantitation of chlorothalonil,
    HCB and PCBN at levels of 0.01 mg/kg, 0.003 mg/kg and 0.005 mg/kg
    respectively, although validation levels were generally higher and
    background apparent residues can exceed these levels in specific
    cases.

         The analytical methods were validated on fortified samples and a
    tumble extraction of chopped samples was utilised. It is not clear
    whether these procedures quantitatively remove field incurred residues
    or whether maceration techniques might be more efficient. Extraction
    of chlorothalonil, HCB and PCBN by maceration was compared with tumble
    extraction on field treated oranges, but residues were too low for
    firm conclusions on relative extraction efficiencies. Also, residues
    were not high enough to draw firm conclusions as intended on the
    possibility of movement of residues from the peel into the fruit,
    although earlier studies (1974 Evaluations) indicated that most of the
    residue of chlorothalonil per se is on the surface of numerous
    vegetables, with trace residues in the pulp of citrus. The Meeting was
    informed that these studies had recently been repeated at higher
    fortification levels.

         An additional study submitted to this Meeting, in which
    chlorothalonil fortified green beans and tomatoes were simmered in
    loosely covered and uncovered vessels (Diamond Shamrock 1981a),
    confirms results from earlier studies (Diamond Shamrock 1981b), which
    show that under these experimental conditions, the majority of the
    chlorothalonil is lost (over 85%), presumably to volatilization or co-
    distillation. However, some results from these recent studies are
    quantitatively somewhat different and even qualitatively inconsistent
    in some respects with those of earlier similar open studies.

         In the study submitted to this Meeting, chlorothalonil losses
    from cooking tomatoes under open conditions were somewhat less than
    previously (85% versus 98%) and in tomatoes and beans the
    radioactivity in the aqueous phase of total residual activity is
    somewhat less under open cooking conditions than previously (9 to 18%
    versus 25 to 30%). Of more significance is the conclusion from the
    more recent studies that the major residue in the organic phase from
    open cooking (including cooking with a loose cover) of chlorothalonil
    fortified tomatoes or beans is chlorothalonil, with negligible
    hydrolysis to DS-3701. The earlier studies with open cooking of beans
    (Diamond Shamrock 1981b) showed no residues of chlorothalonil (or
    DS-19221) in the organic phase, but 57% of the radioactivity was
    identified as DS-3701 and 43% was unidentified radioactivity near the
    origin. Similar results were previously found under reflux conditions,
    although 15% of the organic phase residue was chlorothalonil. There is
    no known explanation for this apparent inconsistency between these
    studies.

         It was also observed that while the authors of the recent studies
    considered unquantified radioactivity at the origin of the thin layer
    chromatogram to be artifacts, unidentified near-origin residues of
    radioactivity in the organic phase from the open cooking of beans in
    the earlier studies amounted to 43% of the residual organic phase
    radioactivity (1.7% of applied).

         There are, therefore, uncertainties remaining as to the nature of
    chlorothalonil degradation products resulting from the open cooking of
    chlorothalonil in the presence of foods. Since samples in these
    studies were fortified just prior to simmering, no firm conclusions
    can yet be drawn with regard to the nature or quantity of residues
    that may be present from the cooking of foods with field-incurred
    residues.

         Additional information on chlorothalonil residues and use
    patterns for grapes were submitted in response to the request of the
    1981 Codex Committee on Pesticide Residues (Report, Alinorm 82/83,
    para. 93). However, because of late receipt, they must be reviewed at
    a future meeting.

    Level causing no toxicological effect

         Rat:  10 ppm in the diet, equivalent to 0.5 mg/kg bw/day
         Dog:  120 ppm in the diet, equivalent to 3 mg/kg bw/day

    Estimate of temporary acceptable daily intake for man

         0 - 0.005 mg/kg bw

    RECOMMENDATIONS OF RESIDUE LIMITS

         No changes in previous estimates of chlorothalonil residues are
    required, and data and information are inadequate to estimate
    additional limits.

    FURTHER WORK OR INFORMATION

    Required (by 1983)

    1.   Studies indicating the extent to which chlorothalonil is
         metabolized to 4-hydroxy-2,5,6-trichloroisophthalonitrile in
         non-ruminant mammals.

    2.   Studies of the relative toxicity of chlorothalonil and 4-hydroxy-
         2,5,6-trichloroisophthalonitrile with respect to nephrotoxicity.

    3.   Submission of mutagenicity tests with chlorothalonil and with
         4-hydroxy-2,5,6-trichloroisophthalonitrile.

    Desirable

    1.   Analyses of chlorothalonil-treated animal feed items, processed
         and unprocessed, for residues of PCBN, for example, bean and
         peanut vines.

    2.   Information on possible PCBN residues in tissues and milk of
         dairy cattle fed a diet containing chlorothalonil.

    3.   Results of recently completed studies on the efficiency of
         "tumble extraction" of field-incurred residues of chlorothalonil,
         HCB and PCBN.

    4.   Explanation of apparent inconsistencies in studies on the nature
         of residues resulting from the cooking of chlorothalonil-treated
         foods.

    REFERENCES

    Barry, T.L., Gretch, F.M. and Rosen, J.D. Identification of
    1977      pentachloronitrobenzonitrile residues in field crops.
              Bulletin of Environmental Contamination and Toxicology,
              18: 691-696.

    Diamond Shamrock. Toxicological reports submitted to the 1981 JMPR by
    1980      Diamond Shamrock Corporation.(Unpublished)

    Diamond Shamrock. Effect of simmering upon 2,4,5,6
    1981a     tetrachloroisophthalonitrile (chlorothalonil, DS-2787) with
              vegetables. Document Number: 372-3EF-80-0004-001 (4/29/80).
              Submitted to the 1981 JMPR by Diamond Shamrock Corporation.

    1981b     Effect of Cooking upon 2,4,5,6-tetrachloroisophthalonitrile
              (chlorothalonil DS-2787) and 4-hydroxy-2.5.6-
              trichloroisophthalonitrile (DS-3701) Document No. 238-3EF-
              79-0058-001; 11/9/79), submitted to the 1981 JMPR by Diamond
              Shamrock Corporation.

    1981c     Volume I, Part II - United States tests. Submitted to the
              1981 JMPR by Diamond Shamrock Corporation

         1)   Residues of 2,4,5,6-tetrachloroisphthalonitrile
              (chlorothalonil, DS-2787), Hexachlorobenzene (HCB) and
              Pentachlorobenzonitrile (PCBN) on celery resulting from
              broadcast application of formulated chlorothalonil (Document
              No. 334-3CR-80-0137-001; 10/28/80)

         2)   Residues of 2,4,5,6-tetrachloroisophthalonitrile
              (chlorothalonil, DS-2787), Hexachlorobenzene (HCB) and
              Pentachlorobenzonitrile (PCBN) on cucumbers (Document No.
              334-3CR-80-0156-001; 10/7/80)

         3)   Residues of 2,4,5,6-tetrachloroisophthalonitrile
              (chlorothalonil, DS-2787), Hexachlorobenzene (HCB) and
              Pentachlorobenzonitrile (PCBN) on cucumbers following field
              application of BRAVO 500 by Sprinkler Irrigation (Document
              No. 336-3CR-80-0181-001; 11/5/80)

         4)   Residues of 2,4,5,6-tetrachloroisophthalonitrile
              (chlorothalonil, DS-2787), Hexachlorobenzene (HCB) and
              Pentachlorobenzonitrile (PCBN) on oranges (Document No.
              355-3CR-80-0067-001; 6/19/80)

         5)   Residues on 2,4,5,6-tetrachloroisophthalonitrile
              (chlorothalonil, DS-2787), Hexachlorobenzene (HCB) and
              Pentachlorobenzonitrile (HCBN) on potatoes (Document No.
              334-3CR-81-0043-001; 5/15/81)

         6)   Residues of 2,4,5,6-tetrachloroisophthalonitrile
              (chlorothalonil, DS-2787), Hexachlorobenzene (HCB) and
              Pentachlorobenzonitrile (PCBN) on Snap Beans (Document No.
              334-3CR-80-0143-001; 10/16/80)

         7)   Residues of 2,4,5,6-tetrachloroisophthalonitrile
              (chlorothalonil, DS-2787), Hexachlorobenzene (HCB) and
              Pentachlorobenzonitrile (PCBN) on Soybeans (Document No.
              334-3CR-79-0113-001; 1/7/80)

         8)   Residues of 2,4,5-tetrachloroisophthalonitrile
              (chlorothalonil, DS-2787), Hexachlorobenzene (HCB) and
              Pentachlorobenzonitrile (PCBN) on tomatoes (Document No.
              334-3CR-80-0051-001; 5/30/80)

         9)   Residues of 2,4,5,6-tetrachloroisophthalonitrile
              (chlorothalonil, DS-2787), Hexachlorobenzene (HCB) and
              Pentachlorobenzonitrile (PCBN) on tomatoes following field
              application of BRAVO 500 by sprinkler application (Document
              No. 336-3CR-80-0066-002; 6/19/80)

    1981d     Volume I, Part III, European Studies, submitted to the 1981
              JMPR by Diamond Shamrock Corporation.

         1)   Residues of 2,4,5,6-tetrachloroisophthalonitrile
              (chlorothalonil, DS-2787) and Hexachlorobenzene (HCB) on
              cereals (Wheat)

              - Wheat - Grain and Straw - Hohenaspe, West Germany. (Report
              81/041; 2/27/81)

              - Wheat Grain and Straw - Kleinkarback, West Germany.
              (Report 81/040; 2/27/81)

              - Wheat - Green ears and Grain - Zuidlaarderveen,
              Netherlands. (Report 81/035; 2/2/81)

              - Wheat - Grain - Pugerup, Sweden. (Report 81/036; 2/27/81)

              - Wheat - Grain - Valstad, Sweden. (Report 81/037; 2/27/81)

              - Wheat - Grain - Lundsgarden, Sweden. (Report 81/038;
              2/27/81)

              - Wheat - Grain - Svanerberg, Sweden. (Report 81/039;
              2/27/81)

              - Wheat - Grain - Pugerup, Sweden. (Report 81/029; 1/30/81)

         2)   Residues of 2,4,5,6-tetrachloroisophthalonitrile
              (chlorothalonil, DS-2787) and Hexachlorobenzene (HCB) on
              tomatoes.

              - Tomato Fruit - Bonn, West Germany (Report 81/042; 2/27/81)

              - Tomato Fruit - Haren, Netherlands (Report 81/043; 2/27/81)

         3)   Residues of 2,2,4,5,6-tetrachloroisophthalonitrile
              (chlorothalonil, DS-2787) and Hexachlorobenzene (HCB) on
              potatoes.

              - Tubers and Soil - Libramont, Belgium. (Report 81/014;
              1/28/81)

              - Tubers and Soil - Haren, Netherlands, (Report 81/044;
              2/27/81)

              - Tubers - Lan, Skepparslov, Sweden. (Report 81/023;
              1/29/81)

              - Tubers - Alnarp, Sweden. (Report 81/025; 1/30/81)

              - Tubers - Lan, Knivsta, Sweden. (Trt. 81/021; 1/18/81)

              - Tubers - Lan, Eldsberga, Sweden. (Report 81/027; 1/30/81)

    Netherlands. Residue data provided by The Netherlands Government.
    1981      Sources for numbered references:

         1)   Residues of Chlorothalonil in the leaves of Celeriac, KVW
              (Food Inspection Service, Amsterdam) 211/CvF/PD mrt 1979.

         2)   Residues of chlorothalonil in Blanched Celery, KvW
              212/CvF/PD mrt in 1979.

         3)   Determination of Residual Levels of the Fungicide
              Chlorothalonil in Sampled of Leek Received from AAgrunol,
              Holland; Study Report No. 17, April, 1978, Diamond
              Shamrock/Europe.

         4)   Pflanzenschutzmittel. Rückstände, BASF Report No.s 441 00 F
              80/6E/9E; 441 00 F 80/10E-/13E and 441 00 F 80/1E, dated
              September 9, 1980.


    See Also:
       Toxicological Abbreviations
       Chlorothalonil (EHC 183, 1996)
       Chlorothalonil (HSG 98, 1995)
       Chlorothalonil (ICSC)
       Chlorothalonil (WHO Pesticide Residues Series 4)
       Chlorothalonil (Pesticide residues in food: 1977 evaluations)
       Chlorothalonil (Pesticide residues in food: 1983 evaluations)
       Chlorothalonil (Pesticide residues in food: 1985 evaluations Part II Toxicology)
       Chlorothalonil (Pesticide residues in food: 1987 evaluations Part II Toxicology)
       Chlorothalonil (Pesticide residues in food: 1990 evaluations Toxicology)
       Chlorothalonil (Pesticide residues in food: 1992 evaluations Part II Toxicology)
       Chlorothalonil  (IARC Summary & Evaluation, Volume 30, 1983)
       Chlorothalonil  (IARC Summary & Evaluation, Volume 73, 1999)