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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


    ACEPHATE

    Explanation

         Acephate was reviewed in 1976* and limits were recommended on a
    variety of commodities. Some limits were revised in 1979. Additional
    residue data on cabbage have been submitted to this Meeting and are
    reviewed in this addendum, which should be considered along with
    methamidophos reviewed elsewhere in these evaluations. The Meeting
    also re-examined limits for potatoes, sugar beets and sugar beet
    leaves at the request of the Codex Committee on Pesticide Residues.

    RESIDUES IN FOOD

    USE PATTERN

         No additional national good agricultural practice information for
    cabbage has been provided to the Meeting. The current 5 mg/kg limit
    was based on a 14-day pre-harvest interval and presumably 1.0 kg
    a.i./ha of unspecified formulations. Most of the residue data
    submitted to this Meeting were from residue trials in one country, for
    which multiple treatments at a label rate of 1.1 kg a.i./ha of Orthene
    75S and a pre-harvest interval of 28 days is proposed. No good
    agricultural practice information was available for the European
    countries from which residue data were available. Therefore it could
    not be determined whether the trials represent national good
    agricultural practice.

    RESIDUES RESULTING FROM SUPERVISED TRIALS

         Residue data from field trials were available from four countries
    and are summarized in Tables 1 and 2. Residue data in Table 1 were
    available on the head and cap leaf and on the 7 inner and 4 outer
    wrapper leaves, from which residues on the head plus wrapper leaves
    were calculated based on the weight contribution and residue in each.
    Average weights of the parts as a percentage of their sums were head
    M-66%, seven inner leaves M-19%, and found outer leaves M-15%.
    Residues levels of acephate and methamidophos in the inner and outer
    leaves are summarized in Table 3.

         Because of the degree to which cabbage might be trimmed in
    practice varies with circumstances, data on the total head plus its
    wrapper levels are the most important for estimating maximum residues.
    This is also consistent with the portion of commodity to be analysed
    specified by the Codex Committee on Pesticide Residues.

              

    *    See Annex II for FAO and WHO documentation.

        TABLE 1.  Residues of methamidophos (Ortho 9006) and acephate plus methamidophos (total in mg/kg) in cabbage treated with
              acephate (75S formulation) from field trials in the United States 1
                                                                                                                                 

    Test number 1                                                         Head plus           Head plus 2         Head plus 2
    Location              Number                          Days after      cap leaf            7 inner wrappers    11 wrappers
    Date of application   of              Kg a.i./ha      last                                                                   
    Variety               applications    (litres)        application     ORTHO               ORTHO               ORTHO
                                                                          9006    Total       9006     Total      9006     Total
                                                                                                                                 

                                                                          0.04    0.24        0.15     1.1        0.26     2.5
    T-2513                                                     7          0.03    0.18        0.12     0.81       0.22     2.1

    Iowa                                                                  0.04    0.20        0.09     0.48       0.17     1.2
    10/73                 9               1.12                14          0.03    0.16        0.08     0.39       0.16     1.3

    Danish Ball Head                      (190)                           0.04    0.15        0.05     0.26       0.10     0.66
                                                              21          0.03    0.13        0.07     0.30       0.13     1.0

                                                                          0.04    0.13        0.08     0.25       0.12     0.53
                                                              28          0.03    0.12        0.07     0.27       0.13     0.75

                                                                          0.03    0.15        0.12     0.71       0.22     1.5
    T-2514                                                     7          0.03    0.17        0.14     0.92       0.30     2.4

    Iowa                                  1.12                            0.03    0.14        0.06     0.30       0.12     0.70
    9/73                  5               (190)               14          0.03    0.16        0.09     0.48       0.19     1.5

    Jersey Wakefield                                                      0.00    0.05        0.00     0.09       0.01     0.23
                                                              21          0.00    0.04        0.01     0.07       0.01     0.15

                                                                          0.06    0.34        0.29     2.2        0.43     4.0
    T-2781                                                     7          0.06    0.38        0.24     1.6        0.38     3.9
                                                                                                                                 

    TABLE 1.  (con't)
                                                                                                                                 

    Test number 1                                                         Head plus           Head plus 2         Head plus 2
    Location              Number                          Days after      cap leaf            7 inner wrappers    11 wrappers
    Date of application   of              Kg a.i./ha      last                                                                   
    Variety               applications    (litres)        application     ORTHO               ORTHO               ORTHO
                                                                          9006    Total       9006     Total      9006     Total
                                                                                                                                 

    Florida                                                               0.06    0.32        0.35     2.1        0.46     3.5
    11/73                 6               1.12                14          0.07    0.37        0.28     1.8        0.42     3.3

    Rio Verde                             (190)                           0.05    0.22        0.18     1.2        0.32     2.0
                                                              21          0.05    0.22        0.22     1.1        0.33     2.0

                                                                          0.06    0.21        0.18     0.73       0.28     1.4
                                                              28          0.05    0.19        0.16     0.65       0.27     1.4

                                                                          0.06    0.28        0.18     1.4        0.32     3.3
    T-2782                                                     7          0.05    0.27        0.19     1.6        0.35     3.2

    Florida                                                               0.06    0.28        0.22     1.7        0.31     2.6
    11/73                 6               1.12                14          0.05    0.24        0.22     1.7        0.32     2.6

    Keystone                              (50)                            0.07    0.26        0.12     0.53       0.22     1.3
    Red Head                              (190)               21          0.05    0.20        0.11     0.42       0.21     1.1

                                                                          0.04    0.13        0.07     0.30       0.13     0.81
                                                              28          0.04    0.13        0.06     0.21       0.12     0.60

                                                                          0.07    0.29        0.18     1.1        0.30     2.9
                                                               7          0.07    0.33        0.19     1.8        0.32     4.6

    T-2783                                                                0.07    0.25        0.21     1.1        0.33     2.0
    Florida                                                   14          0.08    0.31        0.23     1.4        0.33     2.7
                                                                                                                                 

    TABLE 1.  (con't)
                                                                                                                                 

    Test number 1                                                         Head plus           Head plus 2         Head plus 2
    Location              Number                          Days after      cap leaf            7 inner wrappers    11 wrappers
    Date of application   of              Kg a.i./ha      last                                                                   
    Variety               applications    (litres)        application     ORTHO               ORTHO               ORTHO
                                                                          9006    Total       9006     Total      9006     Total
                                                                                                                                 

    11/73                 6               1.12                            0.06    0.22        0.14     0.55       0.21     1.0
    Savoy King                            (50)                21          0.07    0.29        0.18     0.81       0.26     1.7

                                          (190)                           0.04    0.11        0.07     0.22       0.10     0.47
                                                              28          0.05    0.14        0.08     0.27       0.13     0.82

                                                                          0.07    0.34        0.30     1.6        0.44     3.2
                                                               7          0.06    0.30        0.23     1.7        0.35     3.3

    T-2784                                                                0.07    0.32        0.32     1.6        0.42     2.4
    Florida               6               1.12                14          0.07    0.32        0.30     1.7        0.40     2.5

    11/73                                 (50)                            0.07    0.30        0.21     1.1        0.32     2.1
    Abbot & Cobb                          (190)               21          0.08    0.34        0.22     1.3        0.33     2.3

    No. 5                                                                 0.05    0.19        0.12     0.57       0.19     1.1
                                                              28          0.05    0.20        0.11     0.55       0.17     1.1

                                                                          0.05    0.37        0.26     2.5        0.46     5.7
    T-3162                5               1.12                 8          0.04    0.28        0.262    2.3        0.392    3.52
    New Jersey                            (95)
    8/74
    Greenback
                                                                                                                                 

    TABLE 1.  (con't)
                                                                                                                                 

    Test number 1                                                         Head plus           Head plus 2         Head plus 2
    Location              Number                          Days after      cap leaf            7 inner wrappers    11 wrappers
    Date of application   of              Kg a.i./ha      last                                                                   
    Variety               applications    (litres)        application     ORTHO               ORTHO               ORTHO
                                                                          9006    Total       9006     Total      9006     Total
                                                                                                                                 

    T-3470                                                                                                        0.07     0.32
    Maryland              5               0.84                24                                                  0.05     0.26
    9/75                                  (95)
    Early Round Dutch
                                                                                                                                 

    1  Chevron, 1981

    2  Calculated residues.

    TABLE 2.  Residues of acephate and methamidophos on acephate-treated cabbage resulting from European field trials
                                                                                                                                        

                                                                          Residues (in mg/kg) at intervals (days)
                                  Application                             after application
                   Country                                                                                                              
    Crop           (Year)                 Rate                            Days
                                  No.     kg a.i./ha     Formulation      after last     Methamidophos       Acephate            Ref 3
                                                                          application
                                                                                                                                        

    Cabbage        France         1       0.45           75S 1                 7         n.d.                0.06                TE-1296
    (heads)        (1974)                                (foliar)                        n.d.                n.d.
                                                                                         n.d.                n.d.

                   (1974)         3       0.45           50 s.p.1              7         n.d.                n.d.                TE-1300
                                                                                         n.d.                0.03
                                                                                         n.d.                0.05

                   Germany 2      3       20.25         50 s.p.               0         n.d.,0.03           0.14,1.0            TE-1498
                   (1976)                 10.5                                                                                  and
                                                                               7         n.d, n.d.           0.02,0.03           TE-1500
                                                                              10         n.d, n.d.           0.08,0.03
                                                                              14         n.d., n.d.          n.d.,0.03
                                                                              21         n.d., n.d.          n.d.,n.d.
                                                                                                                                        

    1  soluble powder;  2  two separate trials;  3  Chevron, 1981.

    TABLE 3.  Summary residues of acephate and methamidophos in leaves of cabbage treated with acephate 1
                                                                                                          

                                7 inner leaves                      next 4 leaves
                                                                                         
    Days                                 Acephate                            Acephate
    after                                +                                   +                     No. of
    application         Methamidophos    Methamidophos      Methamidophos    Methamidophos         samples
                                                                                                          

    7                   0.4-1.0          2-8                0.6-1.4          6-8                   12
                        (0.6)            (4.4)              (1.0)            (11)

    14                  0.2-1.2          0.9-7              0.5-1.4          3-9                   12
                        (0.6)            (3.6)              (0.9)            (8)

    21                  0.02-0.8         0.14-5             0.05-1.2         0.8-10                12
                        (0.4)            (2.1)              (.7)             (5)

    28                  0.1-0.6          0.4-.3             0.3-1            2-7                   10
                        (0.3)            (1.3)              (0.5)            (3.8)
                                                                                                          

    1  See also Table 1; mean residue in parentheses.
             As can be seen in Table 1 the maximum residue of total acephate
    plus methamidophos from proposed application rates and 28-day
    pre-harvest interval is 1.4, and even at seven days it is in mg/kg
    only 4 mg/kg. By difference, maximum residues of acephate per se
    are, therefore, less than the current 5.0 mg/kg limit. The maximum
    residue of methamidophos at any interval is 0.5 mg/kg and, therefore,
    within the current 1.0 mg/kg limit for methamidophos. Overall,
    residues of methamidophos are about 15% of the combined acephate plus
    methamidophos residue.

         As expected, Table 3 shows that residues on the outer leaves have
    much higher residues (up to about 17 mg/kg acephate) than the whole
    plant or trimmed head.

         It can be seen in Table 2 that residues of acephate on cabbage
    heads from the conditions of the European trials are well below the
    current 5.0 mg/kg limit. These data are not as useful as they might
    be, as it is not known whether these uses represent approved or
    proposed good agricultural practices or whether they reflect those
    that would result in maximum residues.

         The analytical method used in the residue trials (RM - 12A) was
    reviewed in 1976.

    EVALUATION

    APPRAISAL

         The meeting examined residues data on cabbage from supervised
    trials reflecting proposed good agricultural practices. From these
    data the meeting concluded that there is no need to revise the current
    5.0 mg/kg limit.

         The Twelfth Session of CCPR requested the JMPR to reconsider
    the assessments of the data on acephate in potatoes, sugar beet and
    sugar beet leaves made in 1976. The meeting confirmed that the data
    supported the proposal of 10 mg/kg for sugar beet leaves but
    re-estimated the maximum residue levels in potatoes at 0.5 mg/kg
    with an interval of 14 days (previously 1 mg/kg) with an interval of
    3 days and in sugar beet at 0.1 mg/kg (previously 1 mg/kg). These
    re-estimates are suitable for the establishment of revised limits.

    FURTHER WORK OR INFORMATION

    Desirable

    Information on current good agricultural practices.

    REFERENCES

    Chevron Chemical Company. NOS. T-2513, T-2514, T-2781, T-2782, T-2783,
    1981      T-2784, T-3162, T-3470, TE-1296, TE-1300, TE-1498 and TE-
              1500. Submitted by Chevron Chemical Company to the 1981
              Joint Meeting. (Unpublished)


    See Also:
       Toxicological Abbreviations
       Acephate (ICSC)
       Acephate (Pesticide residues in food: 1976 evaluations)
       Acephate (Pesticide residues in food: 1979 evaluations)
       Acephate (Pesticide residues in food: 1982 evaluations)
       Acephate (Pesticide residues in food: 1984 evaluations)
       Acephate (Pesticide residues in food: 1984 evaluations)
       Acephate (Pesticide residues in food: 1987 evaluations Part II Toxicology)
       Acephate (Pesticide residues in food: 1988 evaluations Part II Toxicology)
       Acephate (Pesticide residues in food: 1990 evaluations Toxicology)
       Acephate (JMPR Evaluations 2002 Part II Toxicological)
       Acephate (JMPR Evaluations 2005 Part II Toxicological)