This report represents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of various flavouring agents, with a view to concluding as to safety concerns and to preparing specifications for identity and purity. The Committee also evaluated the risk posed by two food contaminants, with the aim of deriving tolerable intakes where appropriate and advising on risk management options for the purpose of public health protection. The first part of the report contains a general discussion of the principles governing the toxicological evaluation of and assessment of dietary exposure to food additives (particularly flavouring agents) and contaminants. A summary follows of the Committee's evaluations of technical, toxicological and dietary exposure data for 12 groups of flavouring agents (alicyclic ketones, secondary alcohols and related esters; alicyclic primary alcohols, aldehydes, acids and related esters; aliphatic acyclic and alicyclic alpha-diketones and related alpha-hydroxyketones; aliphatic acyclic and alicyclic terpenoid tertiary alcohols and structurally related substances; aliphatic and aromatic amines and amides; aliphatic lactones; aliphatic primary alcohols, aldehydes, carboxylic acids, acetals and esters containing additional oxygenated functional groups; aliphatic secondary alcohols, ketones and related esters and acetals; aromatic substituted secondary alcohols, ketones and related esters; benzyl derivatives; phenol and phenol derivatives; and simple aliphatic and aromatic sulfides and thiols) and two food contaminants (cadmium and lead). Specifications for the following food additives were revised: activated carbon, cassia gum, indigotine, steviol glycosides, sucrose esters of fatty acids, sucrose monoesters of lauric, palmitic or stearic acid and titanium dioxide. Specifications for the following flavouring agents were revised: 4-carvomenthol and 5,6,7,8-tetrahydroquinoxaline. Annexed to the report are tables summarizing the Committee's recommendations for dietary exposures to and toxicological evaluations of the flavouring agents and contaminants considered.