Prepared by:
          The 50th meeting of the Joint FAO/WHO Expert
          Committee on Food Additives (JECFA)

        World Health Organization, Geneva 1998

    This publication is a contribution to the International Programme on
    Chemical Safety.

    The International Programme on Chemical Safety (IPCS), established in
    1980, is a joint venture of the United Nations Environment Programme
    (UNEP), the International Labour Organisation (ILO), and the World
    Health Organization (WHO). The overall objectives of the IPCS are to
    establish the scientific basis for assessing the risk to human health
    and the environment from exposure to chemicals, through international
    peer-review processes, as a prerequisite for the promotion of chemical
    safety, and to provide technical assistance in strengthening national
    capacities for the sound management of chemicals.

    The Inter-Organization Programme for the Sound Management of Chemicals
    (IOMC) was established in 1995 by UNEP, ILO, the Food and Agriculture
    Organization of the United Nations, WHO, the United Nations Industrial
    Development Organization, and the Organisation for Economic
    Co-operation and Development (Participating Organizations), following
    recommendations made by the 1992 United Nations Conference on
    Environment and Development to strengthen cooperation and increase
    coordination in the field of chemical safety. The purpose of the IOMC
    is to promote coordination of the policies and activities pursued by
    the Participating Organizations, jointly or separately, to achieve the
    sound management of chemicals in relation to human health and the

    Health & Environment International, Ltd, by agreement with WHO,
    performed independent literature searches on some of the substances on
    which data are summarized in this document in order to ensure that all
    relevant toxicological and related information was reviewed.



    Anthelminthic agents
         Febantel, fenbendazole, and oxfendazole
    Antimicrobial agents
    Antiprotozoal agents
    Production aid
         Recombinant bovine somatotropins
    Tranquilizing agent


    Annex 1   Reports and other documents resulting from previous meetings
              of the Joint FAO/WHO Expert Committee on Food Additives

    Annex 2   Abbreviations

    Annex 3   Participants in the fiftieth meeting of the Joint FAO/WHO
              Expert Committee on Food Additives

    Annex 4   Recommendations on compounds on the Agenda and further
              toxicological studies and information required



         The monographs contained in this volume were prepared at the
    fiftieth meeting of the Joint FAO/WHO Expert Committee on Food
    Additives (JECFA), which met at FAO Headquarters in Rome, Italy, 17-26
    February 1998. These monographs summarize the safety data on selected
    veterinary drug residues reviewed by the Committee.

         The fifteth report of JECFA will be published by the World Health
    Organization in the WHO Technical Report Series. Reports and other
    documents resulting from previous meetings of JECFA are listed in
    Annex 1. The participants in the meeting are listed in Annex 2 of the
    present publication; a summary of the conclusions of the Committee is
    given in Annex 3. Some of the substances listed in Annex 3 were
    evaluated at the meeting only for residues.

         Monographs on residues of the veterinary drugs that were
    evaluated at the fiftieth meeting of JECFA will be issued separately
    by FAO as Food Nutrition Paper No. 41/11. The toxicological monographs
    in the present publication should be read in conjunction with the
    monographs on residues and the report.

         JECFA serves as a scientific advisory body to FAO, WHO, their
    Member States, and the Codex Alimentarius Commission, primarily
    through the Codex Committee on Food Additives and Contaminants and the
    Codex Committee on Residues of Veterinary Drugs in Foods, regarding
    the safety of food additives, residues of veterinary drugs, naturally
    occurring toxicants, and contaminants in food. Committees accomplish
    this task by preparing reports of their meetings and publishing
    specifications or residue monographs and toxicological monographs,
    such as those contained in this volume, on substances that they have

         The 10 previous meetings of the Committee to consider residues of
    veterinary drugs in food (Annex 1, references 80, 85, 91, 97, 104,
    110, 113, 119, 125, and 128) had been held in response to the
    recommendations of the Joint FAO/WHO Expert Consultation held in 1984.
    The Committee's purpose was to provide guidance to FAO and WHO Member
    States and to the Codex Alimentarius Commission on public health
    issues pertaining to residues of veterinary drugs in foods of animal

         The toxicological monographs contained in this volume are based
    upon working papers that were prepared by Temporary Advisers. A
    special acknowledgement is given at the beginning of each monograph to
    those who prepared these working papers.

         Many proprietary unpublished reports are referenced. These were
    voluntarily submitted to the Committee by various producers of the
    veterinary drugs under review and in many cases represent the only
    data on safety available on those substances. The Temporary Advisers
    based the working papers they developed on all of the data that were
    submitted, and all of these reports were available to the Committee
    when it made its evaluations. The monographs were edited by Professor
    E. Heseltine, Lajarthe, 24290 St Léon-sur-Vézère, France.

         The preparation and editing of the monographs included in this
    volume were made possible through the technical and financial
    contributions of the Participating Institutions of the International
    Programme on Chemical Safety (IPCS), which supports the activities of

         The designations employed and the presentation of the material in
    this publication do not imply the expression of any opinion whatsoever
    on the part of the organizations participating in the IPCS concerning
    the legal status of any country, territory, city, or area or its
    authorities, or concerning the delimitation of its frontiers or
    boundaries. The mention of specific companies or of certain
    manufacturers' products does not imply that they are endorsed or
    recommended by those organizations in preference to others of a
    similar nature that are not mentioned.

         Any comments or new information on the biological or
    toxicological properties of the compounds evaluated in this
    publication should be addressed to: Joint WHO Secretary of the Joint
    FAO/WHO Expert Committee on Food Additives, International Programme on
    Chemical Safety, World Health Organization, Avenue Appia, 1211 Geneva
    27, Switzerland.

    See Also:
       Toxicological Abbreviations