A safe food supply is a legitimate expectation of consumers, which the food industry must meet. Allergic reactions to food are recognised as a significant public health problem. Protecting allergic consumers against such reactions, while minimising the impact of food allergy on their quality of life, poses a challenge to the industry. Risk assessment is the process whereby the likelihood of an adverse event is related to exposure. Allergic reactions to foods can arise in one of three ways, which are not mutually exclusive. Firstly, a known allergen may be present in a food at a level above that at which the allergic individual reacts, secondly, an individual may react to a known or novel allergen because of sensitisation to another, cross-reactive, allergen and finally sensitisation may occur to a novel allergen, followed by reaction on subsequent exposure. A total absence of risk of reaction to an allergen implies no exposure, a situation which in most food manufacturing environments is unrealistic, and in any event would not help in the context of novel allergens. Possible approaches to risk assessment for food allergy in each of the contexts described above are examined, together with their limitations.