Irradiated Food

Food absorbs energy when it is exposed to ionising radiation. The amount of energy absorbed is called 'absorbed dose', which is measured in units of Gray (Gy). The energy absorbed by the food causes the formation of short-lived molecules known as free radicals, which kill micro-organisms and also interact with other food molecules.

Free radicals are formed by almost all food processing techniques, including cooking, chopping and grinding. Radiation also kills bacteria directly by affecting their DNA.

There is only one source of ionising radiation permitted for food irradiation in the UK: gamma rays from cobalt-60.


Current national regulations allow for the irradiation of seven categories of food: fruit, vegetables, cereals, bulbs and tubers, spices and condiments, fish and shellfish, and poultry. However, only one UK licence, for the irradiation of a number of herbs and spices, has so far been granted.