PARATHION-METHYL                                JMPR 1972


    This pesticide was evaluated by the 1968 Joint Meeting and several
    items of information were required before 30 June 1972 (FAO/WHO,
    1969). Data concerning some of the questions became available and are


    1.   Data on metabolites in plants and animal products

         No new data available.

    2.   Data from other countries than the Federal Republic of Germany
         and U.S.A.

         Extensive information was obtained on use patterns in many
         countries and areas of the world, dosage rates and frequencies of
         application (see Table 1). However, no information became
         available on residue levels resulting from supervised trials on
         uses corresponding with the recommended uses in these areas.

         Furthermore, since the 1968 Joint Meeting the use pattern, for
         example in the USA, has been changed and also expanded; national
         tolerances have been established for many crops, which differ
         from the tolerance levels proposed by the 1968 Joint Meeting. No
         data which could support any changes in levels were available for
         evaluation at this time.

    3.   Data on rice

         The only new data available on rice are given in Table 1.

    4.   Residues in food moving in commerce

         Residue analysis carried out in the Federal Republic of Germany
         between 1965 and 1968 on domestic and imported fruit and
         vegetables showed that out of a total of 228 samples, six samples
         of apples contained parathion-methyl ranging between <0.1 and
         0.5 ppm and one apple contained <0.01 ppm, whereas one sample of
         apricots and one sample of lettuce contained <0.01 and <0.1
         ppm, respectively (Krause and Kirchhoff, 1969).

         In a study on pesticide residue levels in food in the U.S.A.
         (July 1963 - July 1969), residues of parathion-methyl could only
         be determined in leaf and stem vegetables and in root vegetables,
         and not in the other 10 of 12 separate food classes.

        TABLE 1  Use patterns of parathion-methyl1


    Crops                    Dosage rates        Countries                PHI                 Applications
                             (kg a.i./ha, or     or areas                 (weeks)             (no.)
                             as % a.i. w/v)

    pome and stone           0.025 - 0.05%       Eur., Ocean.             2-3                 1-3

    citrus fruits            0.025 - 0.075%      Asia, Amer.(S)           2                   1-2

    grapes                   0.025 - 0.075%      Amer.(S), Eur.           2-3                 2-3

    pineapple                0.05 - 0.075%       Afr., Amer. (C.,S.)      -                   2-4


     beans, brassicas,
     cucumbers, onions       0.025 - 0.05%       Afr., Amer(C.,S.)        2-3                 2-4
     potatoes, tomatoes                          Asia, Eur., Ocean.

    Field crops
    cereals (including
    maize, excluding         0.025%              Amer.(S)                 early               2
    rice)                                                                 growing

    Rice                     0.4 - 0.8.kg/ha     Amer.(S), Asia           3                   2-3

    Cotton                   0.5 - 2 kg/ha       Afr., Amer.(S), Asia                         2-6

                             0.5 - 2 kg/ha       Amer (C)                 -                   6-12

    TABLE 1  (Cont'd.)


    Crops                    Dosage rates        Countries                PHI                 Applications
                             (kg a.i./ha, or     or areas                 (weeks)             (no.)
                             as % a.i. w/v)

    Peanut                   0.025 - 0.05%       Amer:(S), Asia           -                   1-2

    Sugarcane                0.05%               Asia                     early growing       1-3

    Coffee                   0.025 - 0.075%      Afr., Amer(C.,S.)        2                   1-2

    Tobacco                  0.025 - 0.05%       Amer.(C.,S.), Asia       -                   1-4

    1  Abbreviations used:   PHI = pre-harvest intervals. Afr. Africa.
                             Amer.(C.,S.) = Central, South America
                             Asia (S,E,SE) = resp. South, East and South-East Asia.
                             Eur. = Europe
                             Ocean. = Oceania: Australia, New Zealand, etc.

         Residue incidence reported by Duggan et al., (1971) is given in
         Table 2.

    TABLE 2

    Parathion-methyl residues in vegetables (1963-1969)

                                  Samples analysed         Incidence (%)

    Leafy and stem vegetables

    domestic                      13 864                   6.1
    imported                      153                      -

    Root vegetables

    domestic                      13 561                   1.3
    imported                      533                      1.2

    In the period 1966 -1969 the residue levels of parathion-methyl in
    leaf and stem vegetables and in root vegetables showed distribution
    given in Table 3.

    TABLE 3  Parathion-methyl residues in vegetables (1966-1969)


                      Samples     Trace     % of samples in ranges (ppm)
                      analysed    (0.03)    0.04-0.1     0.1-1      >1

    Leaf and stem     9 813       2.34      1.47         2.25       0.05

    Root vegetables   8 243       0.23      0.12         0.20       -

    5.   Data on residue levels in total diet studies

         Results from a total diet study carried out in U.S.A. (June 1968
         - April 1970) (Duggan and Corneliussen, 1972) showed that only
         the leafy vegetable class of the twelve separate food classes
         examined contained parathion-methyl and that it was present only
         in trace amounts, i.e., <0.001 mg/day.

         Corneliussen (1972) showed in a subsequent report (June 1969 -
         April 1970) the occurrence of parathion-methyl in 6 out of 360
         total diet composites ranging from 0.003 - 0.023 ppm.

         Similarly, Smith (1972) reported that in a total diet study
         carried out in Canada in 1970 parathion-methyl was only
         determined in the leafy vegetable class of 12 separate food
         classes. Residues in 40 g of prepared leafy vegetable composite
         per day were 0.010 ppm in the second quarter of 1970 (average of
         1970 0.005 ppm). It was not detected in a total diet survey in
         England and Wales (Abbott et al., 1970).

    6.   Methods of residue analysis

         For the determination of parathion-methyl in food products,
         Camoni et al., (1968) used a combined Hyflo-Supercel, Florisil
         and animal charcoal column clean-up. The residues were detected
         by TLC and colorimetric techniques, followed by a GLC
         determination. Rippel and Kovac (1968) determined residues of
         parathion-methyl in citrus fruit juices by extraction from a
         mixed sample/silica gel column, separation on TLC and
         colorimetric determination; the limit of detection was 0.2 ppm.
         Residues of parathion-methyl in rats and chickens have been
         detected by TLC (Beck and Sherman, 1968). Acetonitrile extracts
         were developed on silica gel G plates with a chloroform/carbon
         tetrachloride mixture and visualized with ethanolic sodium
         hydroxide. This method was proposed as a quantitative screening
         procedure supplementary to cholinesterase activity estimation.
         Gas chromatography with several different detectors has been
         reported for the determination of residues. For residues in rats,
         Gabica et al. (1971) used the flame photometric detector for
         levels as low as 0.003 ppm. Suzuki et al. (1968) analyzed rice
         grains containing 0.1 - 10 ppm of parathion-methyl using the
         electron capture detector. Residues in the range 0.2 - 40.0 ppm
         present in green and cured alfalfa were determined using a
         thermionic detector (Waldron and Goleman, 1969). The multiresidue
         procedures described by Abbott et al. (1970) for total diet
         samples are also applicable to parathion-methyl residues.

         Specifications for the parathion-methyl formulated products most
         commonly used are developed and are available (FAO, 1971).


    Because of the lack of relevant data on residue levels from supervised
    trials, as mentioned above, the Meeting was not able to propose any
    changes in the tolerance figures established in the 1968 Meeting or to
    propose tolerance figures for other crops or commodities.

    The data on which the temporary ADI for parathion-methyl were based
    were re-evaluated, and it was decided to extend the temporary ADI for
    a further three-year period.


    REQUIRED (by 30 June 1975)

    1.   Data on supervised trials in various areas, including the
         currently recommended rates of application and pre-harvest
         intervals on those crops for which insufficient information is

    2.   Data on residues in food moving in commerce.


    Abbott, D.C., Crisp, S., Tarrant, K.R. and Tatton, J. O'G. (1970)
    Pesticide residues in the total diet in England and Wales, 1966-1967.
    III - Organophosphorus pesticide residues in the total diet. Pestic.
    Sci., 1: 10-13.

    Beck, J. and Sherman, M. (1968) Detection by TLC of organophosphorus
    insecticides in acutely poisoned rats and chickens. Acta Pharmacol.
    Toxicol., 26: 35-40.

    Camoni, I., Gandolfo, N., Ramelli, G.C., Sampaolo, A. and Binetti, L.
    (1968) Analytical procedure for the detection and determination of
    parathion and methyl-parathion in food products. Bollettino dei
    Laboratori Chimica Provinciali. 19: 615-629.

    Corneliussen, P.E. (1972) Pesticide residue samples in total diet
    samples (VI). Pestic. Monit. J., 5: 313-321.

    Duggan, R.E., Lipscomb, G.Q., Cox, E.L., Heatwole, R.E. and Kling,
    R.C. (1971) Pesticide residue levels in foods in the United States
    from July 1, 1963 to June 30, 1969. Pestic. Monit. J., 73-212.

    Duggan, R.E. and Corneliussen, P.E. (1972) Dietary intake of pesticide
    chemicals in the United States, III, June 1968 - April 1970. Pestic.
    Monit. J., 5: 331-341.

    FAO/WHO. (1965) Evaluation of the toxicity of pesticide residues in
    food. FAO Meeting Report No. PL/1965/10/1; WHO/Food Add./27.65

    FAO/WHO. (1968) 1967 evaluations of some pesticide residues in food.
    FAO/PL: 1967/M/11/1; WHO/Food Add./68.30.

    FAO (1971) Parathion-methyl. FAO specifications for plant protection
    products. AGP:CP/33.

    Gabica, J., Wyllie, J., Watson, M. and Benson, W.W. (1971) Example of
    flame photometric analysis for methyl-parathion in rat whole blood and
    brain tissue. Analyt. Chem., 43: 1102-1105.

    Koen, J.G. and Huber, J.F.K. (1970) A rapid method for residue
    analysis by column liquid chromatography with polarographic detection
    - Application to the determination of parathion and methyl-parathion
    on crops. Analytica Chim. Acta, 51: 303-307.

    Krause, C. and Kirchhoff, J. (1969) Organophosphatrückstünde auf
    Marktproben von Obst und Gemüse sowie auf Getreide erzeugnissen.
    Nachrichlinblitt das Deutschen Pflanzenschutzdienstes, 21(6): 81-84.

    Ott, D.E. and Gunther, F.A. (1968) Automated analysis of
    organophosphorus insecticides by wet digestion - oxidation and
    colorimetric determination of the derived orthophosphate. J. ass. off.
    analyt. Chem., 51: 697-708.

    Rippel, A. and Kovac, J. (1968) Determination of parathion-methyl in
    citrus fruit juices. Nahrung, 12: 711-714 (in German).

    Smith, D.C., Sandi, E. and Leduc, R. (1972) Pesticide residues in the
    total diet in Canada. Pestic. Sci., 3: 207-211.

    Suzuki, K., Goto, S. and Kashiwa, T. (1968) Residue analysis of
    agricultural chemicals. I. Determination of parathion-methyl in rice
    grains by gas chromatography with electron-capture detection. Japan
    Analyst, 17: 187-191 (in Japanese).

    Waldron, A.C. and Goleman, D.L. (1969) Ethyl and methyl-parathion
    residues in green and cured alfalfa. J. Agr. Fd. Chem., 17: 1066-1069.

    See Also:
       Toxicological Abbreviations
       Parathion-methyl (FAO/PL:1968/M/9/1)
       Parathion-methyl (WHO Pesticide Residues Series 5)
       Parathion-methyl (Pesticide residues in food: 1978 evaluations)
       Parathion-methyl (Pesticide residues in food: 1979 evaluations)
       Parathion-methyl (Pesticide residues in food: 1980 evaluations)
       Parathion-methyl (Pesticide residues in food: 1984 evaluations)
       Parathion-methyl (Pesticide residues in food: 1995 evaluations Part II Toxicological & Environmental)