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    PESTICIDE RESIDUES IN FOOD - 1983


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    EVALUATIONS 1983





    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, 5 - 14 December 1983

    Food and Agriculture Organization of the United Nations
    Rome 1985


    CHLORPYRIFOS

    RESIDUES

    Explanation

         Chlorpyrifos was reviewed by the Joint Meetings of 1972, 1974,
    1975, 1977, 1981 and 1982.1  An acceptable daily intake (ADI) of
    0-0.01 mg/kg b.w. was estimated by the 1982 Meeting and MRLs on a
    number of food commodities, including grapes, are under consideration
    in the Codex Committee on Pesticide Residues (CCPR).

         Residues data following the preharvest application of
    chlorpyrifos to grapes to provide protection to mature, drying and
    dried vine fruit have been evaluated.

    RESIDUES IN FOOD AND THEIR EVALUATION

    USE PATTERN

         Ripe grapes grown for the production of dried fruit are attacked
    by Ephestia figulillela, Drosophila spp. and Carpophilus spp.
    It has been shown that preharvest sprays with chlorpyrifos can reduce
    damage. Recommended use is to spray the ripening fruit with a
    200 mg/kg solution (20 g a.i. in 100 litres of water) 21 days prior to
    harvest (McDonald et al. 1983).

    RESIDUES RESULTING FROM SUPERVISED TRIALS

    Grapes

         Grape vines in Victoria, Australia, were sprayed once with
    Lorsban 50 EC (50 percent chlorpyrifos) during early maturation.
    Application rates of 428.5 g, 43 g and 17.0 g a.i./100 litres of water
    were used to achieve target residues of 50, 5 and 2 mg/kg. Actual
    initial residues were higher than expected at 73.8, 9.5 and 2.7 mg/kg.
    These initial deposits vary with weight of fruit, volume of spray
    required for complete coverage and retention by the surface of the
    fruit.

         Fruit was harvested on four occasions (0, 8, 36 and 51 days after
    spraying) during the maturation period. Sampled fruit was subsampled
    for analysis and dried for 21 days (the normal commercial drying
    period) and again sampled for analysis. Table 1 shows the results
    obtained (Sweden 1983).

              

    1  See Annex 2 for FAO and WHO documentation.

        Table 1   Residues of Chlorpyrifos in Sultanas
                                                                                             

      Application rate            Preharvest interval            Residue (mg/kg)
    (mg/kg spray concen.)              (days)              at harvest     on dried fruit
                                                                          21 days postharvest
                                                                                             

         4 285                            0                   73.8           68
                                          8                         44.6                   38
                                         36                            7                    7
                                         51                          4.7                    9

           430                            0                    9.4            9
                                          8                          5.4                    4.4
                                         36                          1.0                    1.1
                                         51                          0.8                    0.9

           170                            0                    2.7            1.6
                                          8                          1.1                    1.3
                                         36                         0.23                    0.4
                                         51                          0.2                    0.3
                                                                                             

    Table 2   Chlorpyrifos Residues in Food Commodities, Sweden
                                                                                                                    

                                                          Number of samples with residues within             Maximum
    Food           Origin         No. of samples                    given ranges (mg/kg)                     residue
                                     analysed         <0.05     0.05-0.12      0.13-0.25      >0.25          (mg/kg)
                                                                                                                    

    Apple          Sweden            286               286
                   Import            917               895         17              3             2             0.64

    Cabbage        Sweden             71                71
                   Import            174               173          1                                          0.052

    Carrot         Sweden            209               209
                   Import            217               215          1              1                           0.17

    Celery         Sweden              8                 8
                   Import             42                35          1                            6             0.77

    Cucumber       Sweden            227               227
                   Import            353               352          1                                          0.060

    Grapes         Import            327               315          6              4             2             0.52

    Grapefruit     Import            148               138          6              4                           0.52

    Iceberg        Sweden            112               112
    lettuce        Import            200               287          3                                          0.090

    Lemon          Import            164               163          1                                          0.13

    Mandarin       Import            292               283          8              1                           0.29

    Oranges        Import            622               572         40              6             4             1.1

    Pear           Sweden            109               109
                   Import            455               454                         1                           0.23
                                                                                                                    

    Table 2  (con't)
                                                                                                                    

                                                          Number of samples with residues within             Maximum
    Food           Origin         No. of samples                    given ranges (mg/kg)                     residue
                                     analysed         <0.05     0.05-0.12      0.13-0.25      >0.25          (mg/kg)
                                                                                                                    

    Pepper         Import            206               198          2              4             2             0.38
    (sweet)

    Tomato         Sweden            205               205
                   Import            500               496          4                                          0.10
                                                                                                                    
    
         Insect control has been achieved at the rate of 170 mg/kg applied
    21 days before harvesting; this corresponds to a residue of
    chlorpyrifos at harvest of approximately 0.5 mg/kg. There is less loss
    of chlorpyrifos after harvest and there may be an increase in actual
    residue content (mg/kg) owing to loss of weight of fruit on drying.

         The treatment registered as good agricultural practice is
    somewhat higher than the minimum treatment tested (but not as high as
    the next rate).

    RESIDUES IN FOOD IN COMMERCE OR AT CONSUMPTION

         From 1 January 1981 to 30 April 1983 monitoring of 8 654 samples
    of food commodities in Sweden gave the results shown in Table 2
    (Sweden 1983). The Swedish MRLs are 0.2 for fruit and vegetables,
    0.05 mg/kg for potatoes and 0.5 mg/kg for citrus fruits.

    APPRAISAL

         The Meeting considered data from trials in which chlorpyrifos was
    applied preharvest to grapes to provide protection to mature, drying
    and dried vine fruit. Residues data on the dried fruit enabled the
    Meeting to estimate an MRL for dried vine fruit (based on supervised
    trials on sultanas) of 2 mg/kg. This was considered suitable for the
    establishment of an MRL. The Meeting confirmed that the residue should
    be defined as the parent compound only.

    RECOMMENDATIONS

         The MRL listed below is recommended. It refers to chlorpyrifos.
    Metabolites are not included. Commodity MRL (mg/kg)

         Dried vine 2
         fruit.

    REFERENCES - RESIDUES

    McDonald, G., Buchanan, G.A. & Griffiths, G.R. Insecticide
    1983      application and degradation in sultana grapes grown for
              drying. Pestic. Sci. 14:528-536.

    Sweden. Data on chlorpyrifos residues submitted to FAO. (Unpublished)
    1983


    See Also:
       Toxicological Abbreviations
       Chlorpyrifos (ICSC)
       Chlorpyrifos (PDS)
       Chlorpyrifos (WHO Pesticide Residues Series 2)
       Chlorpyrifos (WHO Pesticide Residues Series 5)
       Chlorpyrifos (Pesticide residues in food: 1977 evaluations)
       Chlorpyrifos (Pesticide residues in food: 1981 evaluations)
       Chlorpyrifos (Pesticide residues in food: 1982 evaluations)
       Chlorpyrifos (JMPR Evaluations 1999 Part II Toxicological)