FAO, PL:CP/15
    WHO/Food Add./67.32


    The content of this document is the result of the deliberations of the
    Joint Meeting of the FAO Working Party and the WHO Expert Committee on
    Pesticide Residues, which met in Geneva, 14-21 November 1966.1

    1 Report of a Joint Meeting of the FAO Working Party and the WHO
    Expert Committee on Pesticide Residues, FAO Agricultural Studies, in
    press; Wld Hlth Org. techn. Rep. Ser., 1967, in press



    Note to the reader

    The Monographs:







    Ethylene dibromide

    Methyl bromide



    Hydrogen phosphide


    Phenylmercury acetate (and other organomercury compounds)

    Piperonyl butoxide






    A Joint Meeting of the FAO Working Party and the WHO Expert Committee 
    on Pesticide Residues was held in Geneva in November 1966.
    The general considerations, including the principles adopted for the
    evaluation, and a summary of the results of evaluations on a number of
    pesticide residues appear in a publication entitled "Report of a Joint
    Meeting of the FAO Working Party and the WHO Expert Committee on
    Pesticide Residues".a Additional information, such as biological
    data, toxicological evaluation and agricultural data and their
    evaluation, considered at the joint meeting is to be found in this

    As much relevant information as possible has been included in the
    monographs. Wherever possible this has been obtained from the
    published literature, but other sources of information have also been
    used. The members of the meeting thanked all those who had made
    information available to them and offered their apologies to any
    authors whose work may not have been taken into consideration. They
    emphasized the need for the early and complete publication of the
    results of research in this field, particularly of that part which
    could form the basis of the determination of an acceptable daily
    intake for man. This is necessary so that the work reported can be the
    subject of scrutiny and informed criticism by a wider group of
    scientists covering disciplines not necessarily represented at the
    Committee meeting.

    Unpublished data, because they may include more detail than
    published work, may often be required for the determination of
    acceptable daily Intakes. These data must be complete,
    non-confidential and with an indication of the authorship of the
    report. The information will not be considered unless it is received
    at least three months before the announced date of the joint meeting
    in sufficient copies (at least two) to be distributed to suitable

    The acceptable daily intakes have been established according to the 
    principles set out in previous reports. Furthermore, in the
    evaluation of those pesticides for which several long-term studies
    have been reported and the lowest dosage showed an effect of
    questionable significance, a greater margin of safety has been used.
    In other cases a "temporary ADI" has been estimated with the condition
    that additional necessary information be available within a specified
    period of time. The figure will be reviewed within a specified period
    of time as set out in the relevant monographs. If no action has been
    taken to provide this further evidence required, it will be assumed
    that neither the manufacturers nor the user countries are interested
    in continuing the use of the pesticide.

    a FAO Meeting Report, in press; Wld Hlth Org. techn. Rep. Ser.,
      1967, in press

    Certain problems were encountered in the toxicological evaluation of 
    the organochlorine pesticides, which have been used extensively and
    have proved agriculturally efficacious. Many have been shown to be
    persistent and cumulative in the animal and human body. In addition,
    there is evidence that even in low doses they have an effect on the
    liver. During the past few years, evidence has become available that
    these compounds stimulate the activity of microsomal enzymes in the
    liver cells. These may affect the metabolism of other compounds. lt
    was therefore urged that methods of toxicological investigation aimed
    at defining and clarifying the various biological changes seen in the
    reported studies of these compounds be developed, with a view to
    removing doubts which may remain as to their safety in use.

    As used in the following monographs, "tolerance" is the permitted
    concentration of a pesticide residue in or on a food. A "temporary
    tolerance" is given in either of two circumstances: (a) when it is
    derived from a temporary ADI; (b) when it is derived from an ADI which
    could be exceeded when the pesticide is applied according to good
    agricultural practice; such temporary tolerances are valid for a
    specified period during which additional data on toxicity and on the
    disappearance of the pesticide residues during storage and processing
    of food should become available. "Practical Residue Limits" are
    suggested for use by governments as administrative decisions based on
    residues actually found in those cases where unintentional residues of
    pesticides occur in foods from background and environmental

    The monographs only contain comments on the suitability of stated
    methods of residue analysis for specific purposes, the reader being
    referred to publications in the scientific literature for the details
    of the techniques in individual cases. The methods have been
    considered particularly with regard to their suitability for general
    regulatory purposes rather than for use after planned experimental
    application of the pesticides. Partly for this reason and as explained
    in the report of the second session of the FAO Working Party,a
    multidetection systems of analysis have been given some emphasis.
    Whilst the methods referred to, and particularly the clean-up
    procedures, are thought to be adequate, some of them may not have been
    specifically tested for the various foods mentioned. In various
    instances, therefore, the methods may need some modification.
    Accordingly, each laboratory should make a preliminary examination of
    any suggested procedure, in order to obtain satisfactory recoveries.

    a FAO Report No. PL/1965/12.

    Note to the reader

    Any comments on agricultural data and their evaluation should be
    addressed to:

         Crop Protection Branch
         Plant Production and Protection Division
         Food and Agriculture Organization
         Rome, Italy

    Any comments on biological data and toxicological evaluation
    should be addressed to:

         Food Additives Unit
         World Health Organization
         Geneva, Switzerland

    See Also:
       Toxicological Abbreviations