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    AGP:1970/M/12/1

    WHO/FOOD ADD/71.42

    1970 EVALUATIONS OF SOME PESTICIDE RESIDUES IN FOOD

    THE MONOGRAPHS

    Issued jointly by FAO and WHO

    The content of this document is the result of the deliberations of the
    Joint Meeting of the FAO Working Party of Experts and the WHO Expert
    Group on Pesticide Residues, which met in Rome, 9-16 November, 1970.

    FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS

    WORLD HEALTH ORGANIZATION

    Rome, 1971

    CARBARYL

    Explanation

    This compound was evaluated by Joint Meetings in 1966, 1967, 1968 and
    1969 (FAO/WHO, 1967b, 1968b, 1969b and 1970b). A temporary acceptable
    daily intake for man of 0.01 mg/kg was proposed in 1969, to be
    reviewed in 1973. In 1969, temporary tolerances proposed in 1967 and
    others added in 1968 were revised and extended, but that proposed in
    1968 for whole milk was withdrawn.

    Further information required by 30 June 1970 included: (a) results
    from total diet studies, (b) data on residue levels in whole milk, (c)
    data on the disappearance of residues during storage and processing of
    cocoa beans and derived products and of cereals into cereal products,
    More sensitive methods of analysis, especially for total diet studies,
    were considered desirable.

    RESIDUES IN FOOD AND THEIR EVALUATION

    Results of studies on dietary intake in the U.S.A. have been
    summarized by Duggan and Lipscomb (1969). The percentage of total diet
    samples containing carbaryl and the daily intake per kg bodyweight
    were 7.4 and 0.15 mg in 1965, 2.7 and 0.026 mg in 1966, 1.1 and <0.01
    mg in 1967, and were below the limits of measurement in 1968. These
    authors concluded that, for diets in the U.S.A., "Carbamate chemicals
    and carbaryl do not occur at sufficiently high levels or frequencies
    to be considered as contributors to the daily intake of pesticide
    chemicals."

    No new information has been received concerning residue levels in milk
    nor on the fate of residues in storage or processing of cocoa beans or
    cereals; items b, c and d of the information requested therefore
    remain unanswered.

    Evidence on the effect of simple washing on residue levels on cabbage
    and eggplant have been published from India (Mann and Chopra, 1969).
    Samples were taken at intervals up to seven days after the fourth
    application by spraying of carbaryl in nine-week periods, and half of
    these samples on each occasion were washed before analysis. The
    spraying rates, intervals between spraying and harvesting, and the
    residue levels on unwashed and washed samples are given in Table I.

    The temporary tolerance of 5 ppm in poultry set by the 1969 Joint
    Meeting on a whole meat basis, including skin, was referred back by
    the 5th Meeting of the Codex Committee on Pesticide Residues. Further
    data have been provided that show that the distribution of residues
    varies considerably with the method of application of carbaryl. The
    method of analysis was colorimetric and determined carbaryl and
    1-naphthol at 0.1 and. 0.2 ppm, respectively. Residues of 1-naphthol
    never exceeded 10% of those of carbaryl. Even when carbaryl was
    applied at frequent intervals and rates above those recommended,


        TABLE I
                                                                         

    Carbaryl residues (ppm) present after spraying1

    Picking      0.1% (0.62 kg/ha)    0.2% (1.24 kg/ha)   0.4% (2.48 kg/ha)
    interval
    (days)       unwashed   washed    unwashed   washed   unwashed   washed
                                                                         

    Cabbage

    0            14.80      0.97      23.83      1.34     33.86      1.25
    1            9.00       2.08      13.33      3.81     18.57      5.61
    3            5.72       2.77      8.15       3.41     10.41      5.05
    5            3.83       2.88      5.86       2.72     6.99       3.80
    7            2.50       1.44      3.94       2.17     5.13       2.94

    Eggplant

    1            8.33       -         12.22      -        16.86      -
    3            5.29       1.98      7.30       3.14     9.85       4.70
    5            3.58       1.80      5.08       2.55     6.42       3.38
    7            3.05       1.30      4.31       1.99     5.40       2.80
                                                                         

    1  A comparison of the rates of dissipation for washed and unwashed
       cabbage shows that washing removes the initial deposit readily, but
       that carbaryl penetrates into the plant during the first day or two
       to a considerable extent. Comparable deposits and penetration occur
       on the eggplant.
    
    residues after seven days in tissues other than the skin did not
    exceed the limit of measurement. Residues on the skin did not exceed 3
    ppm. Since the skin provides about 9% of the total edible tissues, a
    temporary tolerance of 0.5 ppm for the edible parts of prepared birds
    should be sufficient; the previously recommended figure of 5 ppm
    thereby applies only to the skin of poultry.

    METHODS OF RESIDUE ANALYSIS

    Two methods using GLC with electron capture have recently been
    described. In Cohen et al. (1970) recoveries from spiked samples of
    lettuce and peas were 82% and 87% respectively, from apples, 94% and
    the level of detection in plant material was reported to be 0.1 ppm.
    Tilden and Van Middelem (1970) claim a limit of 0.2 ppm, but were
    unable to avoid a high reagent blank. These methods seem suitable for
    regulatory purposes.


    APPRAISAL

    Further information has been received concerning the levels of
    carbaryl present in various organs and tissues of laying hens and
    turkey poults killed seven days after treatment by various methods of
    external application. This indicates that the temporary tolerance of 5
    ppm for poultry, recommended at the Joint Meeting in December 1969,
    should be adequate for poultry skin, but that the tolerance for
    prepared birds, i.e. the total edible portion, including the skin,
    could be reduced to 0.5 ppm.

    Studies on total dietary intake from the U.S.A. over the period
    1965-1968 showed that intake was rapidly decreasing and was below the
    limit of determination in the final year. Harvest residue data on
    cabbage and eggplant indicate that the recommended tolerance of 5 ppm
    should be retained.

    Two analytical methods using G.L.C. with electron capture detection
    have been described, one reports the lower level of detection to be
    0.1 ppm.

    FURTHER WORK OR INFORMATION

    REQUIRED       (before tolerances can be set for whole milk and milk
                   products)

    Further data on residue levels.

    REFERENCES

    Cohen, I.C., Norcup, J, Ruzicka, J.H.A., and Wheals, B.B. (1970) An
    electron-capture gas chromatographic method for the determination of
    some carbamate insecticides as 2,4-dinitrophenyl derivatives of their
    phenol moieties. J. Chromatog., 49: 215-221.

    Duggan, R.E., and Lipscomb, G.Q. (1969) Dietary intake of pesticide
    chemicals in the United States (II), June 1966 - April 1968. Pestic.
    Monit. J., 2 (4): 153-162.

    Mann, G.S., and Chopra, S.L. (1969) Residues of carbaryl on crops.
    Pestic. Monit. J., 2 (4): 163-166.

    Tilden, R.L. and Van Middelem, G.H. (1970) Determination of carbaryl
    as an amide derivative by electron-capture gas chromatography. J. Agr.
    Food Chem., 18: 154-158.
    


    See Also:
       Toxicological Abbreviations
       Carbaryl (EHC 153, 1994)
       Carbaryl (HSG 78, 1993)
       Carbaryl (ICSC)
       Carbaryl (PIM 147)
       Carbaryl (FAO Meeting Report PL/1965/10/1)
       Carbaryl (FAO/PL:CP/15)
       Carbaryl (FAO/PL:1967/M/11/1)
       Carbaryl (FAO/PL:1968/M/9/1)
       Carbaryl (FAO/PL:1969/M/17/1)
       Carbaryl (WHO Pesticide Residues Series 3)
       Carbaryl (WHO Pesticide Residues Series 5)
       Carbaryl (Pesticide residues in food: 1976 evaluations)
       Carbaryl (Pesticide residues in food: 1977 evaluations)
       Carbaryl (Pesticide residues in food: 1979 evaluations)
       Carbaryl (Pesticide residues in food: 1984 evaluations)
       Carbaryl (Pesticide residues in food: 1996 evaluations Part II Toxicological)
       Carbaryl (JMPR Evaluations 2001 Part II Toxicological)
       Carbaryl (IARC Summary & Evaluation, Volume 12, 1976)