Toxicology of Food Additives

Chemicals have been used to preserve food and to add colour and taste to food for centuries. Following the considerable increase in the use of food additives in processed foods from the mid-twentieth century, safety assessment of food additives has been conducted on a formal basis at national and international levels. Currently, over 400 individual additives are listed by the international Codex Alimentarius for use in food traded around the world. Current approaches to the safety assessment of food additives generally require an extensive database of kinetic, metabolic and toxicity studies to be generated. Toxicity studies are usually conducted in laboratory animals and the types of study generally cover all the various life-stages. Human studies are rarely available, but human data on absorption, metabolism and tolerance may be available. Studies are designed to show, not only any adverse effects, but also to identify doses below which no adverse effects occur (the no observed adverse-effect level or NOAEL). Acceptable daily intakes (ADIs) for food additives are derived by examination of the outcomes of the toxicity studies, and usually are based on the overall NOAEL for the most sensitive effect in the most sensitive species. In order to ensure absence of toxic effects in the exposed human population, conservative ADIs are derived by application of safety or uncertainty factors to the overall NOAEL. Keywords: food additives; safety; Codex Alimentarius; JECFA; SCF; EFSA; FDA; E numbers