Needs and methods for priority setting for estimating the intake of food additives.

Direct measurement of the intake of food additives is a complex, time-consuming and expensive process. Prioritization of intake surveys is important to focus initial attention on those additives of most concern. Intakes at or below the Acceptable Daily Intake (ADI) are not of concern, by definition, and therefore a high priority should be given to those additives for which simple, but conservative, theoretical estimates of potential intake indicate a probability of exceeding the ADI. Although ADI values for different additives are equivalent, because they are based on No-Observed-Adverse-Effect Levels (NOAELs), the risk associated with intakes above the ADI can only be determined by reference back to the data which are the basis for the ADI estimation. In consequence the nature and severity of toxic effects detected in animal experiments above the NOAEL should be taken into account in the prioritization of intake surveys. A scheme is proposed which incorporates both exposure estimation and toxicology in determining which food additives should be allocated a high priority for inclusion in intake surveys.