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    PESTICIDE RESIDUES IN FOOD - 1984


    Sponsored jointly by FAO and WHO






    EVALUATIONS 1984




    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
    Rome, 24 September - 3 October 1984

    Food and Agriculture Organization of the United Nations
    Rome 1985

    PERMETHRIN

    Explanation

         Permethrin was evaluated at the 1979, 1980, 1981, 1982 and 1983
    Meetings (FAO/WHO, 1980, 1981, 1982, 1983, 1984). 1/ Questions
    referred to the JMPR by the 16th Session of the Codex Committee on
    Pesticide Residues led to a review of data available on celery and
    pistachio nuts from the United States.

    RESIDUES IN FOOD AND THEIR EVALUATION

         The permethrin residue levels reviewed below were measured by gas
    chromatography using an electron capture detector, as in the previous
    review (FAO/WHO, 1980).

    USE PATTERN

         Permethrin is registered for use at 110-220 g a.i./ha every 3-5
    days to control vegetable leaf miners, cabbage loopers, granulate
    cutworm, black cutworm, fall armyworm and beet armyworm, with a 
    pre-harvest withholding interval of three days.

    RESIDUES RESULTING FROM SUPERVISED TRIALS

    Celery

         Residues of permethrin in celery resulting from applications of a
    24 percent E.C. formulation during 1977-79 are reported in Table 1.
    After three days, permethrin levels at the lower rate (110 g a.i./ha)
    did not exceed 1.6 mg/kg (mean-1.1 mg/kg) and at the higher rate
    (220 g a.i./ha), with one exception, did not exceed 1.9 mg/kg 
    (mean-1.5 mg/kg). The exception was a value of 3.2 mg/kg (Ussary,
    1977a,b,c,d, 1981).

    Pistachio

         At 220-440 g a.i./ha, permethrin gives good control of peach twig
    borers, 'Navel' orangeworms and chinchbugs.

         Field trials on pistachio were conducted in the United States,
    using a 24 percent E.C. formulation during the 1980-82 growing
    seasons. Trees received two or three applications of permethrin at
    rates of 220-880 g a.i./ha. The last application was made at 5-10
    percent hull split. As expected, permethrin levels/residues in the
    meats of mature pistachios were very low (Table 2). This is because
    the nutmeat is completely protected from direct contact with the spray


              

    1/  See Annex 2 for FAO and WHO documentation.

        TABLE 1.  Permethrin Residues in Celery, from supervised trials, United States

                                                                                       

    Rate                     Application         Interval                 Residue
    (g a.i./ha)         Method         Number    Last application         (mg/kg)
                                                 to sampling (days)
                                                                                       

    110                 Ground           8            0                   2.1
                                                      1                   2.1
                                                      3                   1.6
                                                      7                   0.64
                        Ground           8            0                   1.1
                                                      1                   0.93
                                                      3                   0.87
                                                      7                   0.35
                        Ground          17            0                   1.3
                                                      1                   1.5
                                                      3                   0.72
                                                      7                   0.43
                        Ground          21            0                   3.6
                                                      1                   1.9
                                                      3                   1.4
                                                      7                   0.40
                        Aerial           8            0                   2.8
                                                      1                   2.3
                                                      4                   1.2
                        Aerial           6            0                   1.9
                                                      3                   1.2
                        Aerial           7            1                   0.99
                                                      3                   0.86

    220                 Ground           8            0                   3.3
                                                      1                   4.0
                                                      3                   1.7
                                                      7                   1.2
                        Ground           8            0                   2.7
                                                      1                   1.8
                                                      3                   1.3
                                                      7                   0.87
                        Ground          17            0                   2.8
                                                      1                   3.0
                                                      3                   1.8
                                                      7                   1.4
                        Ground          21            0                   3.2
                                                      1                   3.5
                                                      3                   1.9
                                                      7                   1.4
                                                                                       

    TABLE 1.  (continued)

                                                                                       

    Rate                     Application         Interval                 Residue
    (g a.i./ha)         Method         Number    Last application         (mg/kg)
                                                 to sampling (days)
                                                                                       

                        Aerial           7            0                   3.0
                        Aerial           7            0                   2.0
                                                      3                   1.2
                        Ground           5            0                   1.8
                                                      3                   1.6
                        Ground          11            0                   4.2
                                                      3                   3.2
                                                                                       

    1  The data all relate to untrimmed celery. Data have not been included where there 
       was reason to believe that trimming had occurred. References consulted (Ussary, 
       1977a,b,c,d) were reviewed at the 1979 JMPR.



    TABLE 2.  Permethrin Residues in Pistachio Nuts, from supervised trials, United States

                                                                                         

    Rate of                  No. of              Interval                 Residue
    Application              Applications        Last application         (mg/kg)
                                                 to sampling (days)
                                                                                         

    220                          2                    0                     0.03
                                                      1                     0.02
                                                      3                     0.02
                                                      5                     0.01
    880                          2                    0                     0.03
    (1st application)                                 1                     0.01
    440                                               3                     0.02
    (2nd application)                                 5                     0.02
                                                      7                     0.01
    440                          3                    0                     0.02
                                                      1                     0.01
                                                      3                     0.02
                                                      5                     0.01
                                                      7                    <0.01
    440                          2                    5                     0.01
                                                      7                    <0.01
                                                                                         
    
    solution, and even the shells are largely protected by the outer hull.
    It is likely that the small residues found in pistachio nutmeats were
    the results of contamination (i.e. contact with treated hulls) during
    sample preparation (Fitzpatrick, 1983).

    APPRAISAL

         As requested by the 16th Session of the CCPR, the meeting
    reviewed the data supporting the proposal of 5 mg/kg as an MRL for
    permethrin in celery. Additional new data were available. Good
    agricultural practice requires a maximum rate of 220 g a.i./ha and an
    interval of three to five days between the last application and
    harvest. The meeting noted that only a relatively high number of
    applications (11 per season) at the high rate resulted in a residue
    at three days that exceeded 2 mg/kg. Accordingly, the meeting
    re-estimated the maximum residue level following good agricultural
    practice at 2 mg/kg and withdrew the estimate of 5 mg/kg.

         New data enabled the meeting to estimate a maximum residue level
    at the limit of determination for pistachio nuts, accepting a GAP of
    up to 440 g a.i./ha and an interval of seven days between last
    application and harvest. This is in full accord with prediction, since
    the edible nut is fully protected from direct contact with the
    pesticide.

         At the request of the CCPR, the meeting reviewed the data on
    permethrin on tomatoes referred to in the 1979 monographs. Although,
    on occasion, the initial deposit exceeded 1 mg/kg (but was less than
    2 mg/kg) the levels after three to seven days were below 1 mg/kg.
    Taking into account residues on other fruiting vegetables as well, the
    meeting agreed that further data were desirable if the MRL was to be
    greater than 1 mg/kg.

         In reviewing the data on residues in soybeans at the request of
    the 16th Session of the CCPR, the meeting recognized that residues
    resulting from GAP did not exceed 0.05 mg/kg in the data examined. In
    considering that the edible part of the crop was fully protected, the
    meeting revised its estimate from 0.1 mg/kg to 0.05 mg/kg (at or about
    the limit of determination).

         The meeting drew attention to the fact that the proposed MRL of
    0.1 mg/kg for poultry was based on meat (muscle), whereas the figure
    for carcase meat of cattle, pigs and sheep applied to sampled carcase
    fat. The poultry MRL was correctly recorded in the 1980 evaluations
    but incorrectly recorded as applying to carcase fat in the report.

    RECOMMENDATIONS

         The following estimates of MRLs recommended as suitable for use:

                                                             

    Commodity           MRL
                        (mg/kg)
                                                             

    celery              2         (to replace celery, 5)

    pistachio nuts      0.05*

    soybeans            0.05*     (to replace soybean 0.1)

    tomatoes            1         (to replace tomatoes 2)
                                                             

    *  at or about the limit of determination

    REFERENCES

    Fitzpatrick, R.D. Permethrin residues in pistachio nut meats. Report
    1983      No. TMU 1206/B (Revised) submitted by ICI Americas Inc.
              Agricultural Chemicals Division to FAO (Unpublished)

    Ussary, J.P. Permethrin residues on celery. Report No. TMU 0341/B
    1977a     submitted by ICI Americas Inc. Agricultural Chemicals
              Division to FAO. (Unpublished, previously reviewed by the
              1979 JMPR)

    Ussary, J.P. Permethrin residues on celery. Report No. TMU 0340/B
    1977b     submitted by ICI Americas Inc. Agricultural Chemicals
              Division to FAO. (Unpublished, previously reviewed by the
              1979 JMPR)

    Ussary, J.P. Permethrin residues on celery. Report No. TMU 0342/B
    1977c     submitted by ICI Americas Inc. Agricultural Chemicals
              Division to FAO. (Unpublished, previously reviewed by the
              1979 JMPR)

    Ussary, J.P. Permethrin residues on celery. Report No. TMU 0346/B
    1977b     submitted by ICI Americas Inc. Agricultural Chemicals
              Division to FAO. (Unpublished, previously reviewed by the
              1979 JMPR)

    Ussary, J.P. Permethrin residues on celery. Report No. TMU 0622/B
    1981      submitted by ICI Americas Inc. Agricultural Chemicals
              Division to FAO. (Unpublished)


    See Also:
       Toxicological Abbreviations
       Permethrin (EHC 94, 1990)
       Permethrin (HSG 33, 1989)
       Permethrin (ICSC)
       PERMETHRIN (JECFA Evaluation)
       Permethrin (Pesticide residues in food: 1979 evaluations)
       Permethrin (Pesticide residues in food: 1980 evaluations)
       Permethrin (Pesticide residues in food: 1981 evaluations)
       Permethrin (Pesticide residues in food: 1982 evaluations)
       Permethrin (Pesticide residues in food: 1983 evaluations)
       Permethrin (Pesticide residues in food: 1987 evaluations Part II Toxicology)
       Permethrin (JMPR Evaluations 1999 Part II Toxicological)
       Permethrin (UKPID)
       Permethrin (IARC Summary & Evaluation, Volume 53, 1991)