Food irradiation is the practice of producers subjecting their food products to intense fields of gamma rays, X-rays or high energy electrons before shipping them to market. Irradiation kills harmful bacteria, including E. coli, Salmonella, Staphylococcus among others, thereby reducing the danger of food borne illnesses. It also kills insects and parasites without the use of pesticides. Irradiation inhibits the spoilage of food and can stretch the world’s available food supply. In more than thirty countries around the world, some forty different kinds of food stuffs, including fruits and vegetables, spices, grains, fish, meats and poultry are routinely being irradiated.

The most common method for irradiating food uses radioactive cobalt 60 packaged into thin rods about 45 centimeters long. The rods are stored in a deep pool of water that is surrounded by thick concrete walls. Water absorbs gamma rays, so while the cobalt is immersed it presents little danger to plant employees. The irradiation process goes like this: Metal carriers are stuffed with boxes of food. The carriers slide along an overhead monorail into a chamber containing radioactive cobalt, stored in a pool of water. Hydraulic arms lift the cobalt out of the water pool, exposing the boxes to gamma rays. Depending on the type of food, the duration of exposure varies. Once the food has been irradiated the boxes slide out again on the opposite side. The treated food is loaded onto trucks for shipping to food distributors or directly to restaurants or stores.

Foods treated with radiation bear the green-colored Radura symbol (picture, above) either on the label or on a nearby sign. Food containing irradiated ingredients, however, are not labeled. The FDA may change the label to read ‘treated with cold pasteurization’ method instead of using the term irradiation.