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    INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY

    WORLD HEALTH ORGANIZATION





    SAFETY EVALUATION OF CERTAIN FOOD
    ADDITIVES AND CONTAMINANTS



    WHO FOOD ADDITIVES SERIES: 44





    Prepared by the Fifty-third meeting of the Joint FAO/WHO
    Expert Committee on Food Additives (JECFA)





    World Health Organization, Geneva, 2000
    IPCS - International Programme on Chemical Safety


    SAFETY EVAULATIONS OF GROUPS OF RELATED SUBSTANCES BY THE
    PROCEDURE FOR THE SAFETY EVALUATION OF FLAVOURING AGENTS

    INTRODUCTION

         Two groups of flavouring agents were evaluated by the Procedure
    for the Safety Evaluation of Flavouring Agents outlined in Figure 1
    (Annex 1, references  116,  122, and  131).

         The Committee noted that in applying the Procedure, the substance
    is first assigned to one of the structural classes identified at the
    forty-sixth meeting of the Committee (Annex 1, reference  122):

    *    Class I. Substances that have simple chemical structures and
         efficient modes of metabolism that would suggest a low order of
         toxicity when given by the oral route

    *    Class II. Substances that have structural features that are less
         innocuous than those of substances in Class I but are not
         suggestive of toxicity. Substances in this class may contain
         reactive functional groups.

    *    Class III. Substances that have structural features that permit
         no strong initial presumption of safety or may even suggest
         significant toxicity.

         A key element of the Procedure involves determining whether a
    flavouring agent and the product(s) of its metabolism are innocuous
    and/or endogenous. For the purposes of evaluation, the Committee used
    the following definitions, adapted from the report of its forty-sixth
    meeting:

          Innocuous metabolic products are defined as products that are
    known or readily predicted to be harmless to humans at the estimated
    intake of the flavouring agent.

          Endogenous substances are intermediary metabolites normally
    present in human tissues and fluids, whether free or conjugated;
    hormones and other substances with biochemical or physiological
    regulatory functions are not included. The estimated intake of a
    flavouring agent that is, or is metabolized to, an endogenous
    substance should not give rise to perturbations outside the
    physiological range.

    Intake

         Intakes were estimated from surveys carried out in Europe and the
    United States. Estimates of the intake of flavouring agents by
    populations typically involve the acquisition of data on the amounts
    used in food. In Europe, a survey was conducted in 1995 by the
    International Organization of the Flavor Industry, in which flavour

    manufacturers reported the total amount of each flavouring agent
    incorporated into food sold in the European Union during the previous
    year. Manufacturers were requested to exclude use of flavouring agents
    in pharmaceutical, tobacco, and cosmetic products. In the United
    States, a series of surveys was conducted between 1970 and 1987 by the
    National Academy of Sciences National Research Council (under contract
    to the Food and Drug Administration) in which information was obtained
    from ingredient manufacturers and food processers on the amount of
    each substance destined for addition to the food supply and on the
    usual and maximal levels at which each substance was added to a number
    of broad food categories.

         In using data from these surveys to estimate the intakes of
    flavouring agents, it was assumed that only 60% of the total amount
    used is reported and that the total amount used in food is consumed by
    only 10% of the population.

    Intake              annual volume of production (kg)  109 (g/kg)
    (g/person   =                                                    
    per day)                population of consumer  0.6  365 days

    The population of consumers was assumed to be 32  106 in Europe and  
     24  106 in the United States.

    FIGURE 1


    


    See Also:
       Toxicological Abbreviations