Food Irradiation for Food Safety

Food irradiation has been used for decades to reduce or eliminate organisms that cause disease and spoil foods. In fact, irradiation was first used in the U.S. to ensure the safety of food for astronauts while in space.

Irradiation is very similar to cooking in that the food is exposed to an energy source that reduces the number of harmful bacteria. In cooking, the food is heated to a point that microorganisms are killed, the food consistency is changed and some nutrients are destroyed. With irradiation, radiation passes through the food and some energy is absorbed by the chemical bonds. This causes the bonds to break. There is little change in the consistency or nutritional value of the food. If the food still has living cells such as seeds or "eyes" in potatoes, they will be damaged or killed along with the microorganisms. This helps prolong the shelf life of fresh fruits and vegetables and keeps potatoes from sprouting.

Disease-causing bacteria that can be controlled by low to medium doses of irradiation include E. coli 0157:H7, salmonella, campylobacter, shigella, listeria, Trichinella spiralis and cyclospora.

Food irradiation is approved by the Food and Drug Administration. Each individual food must be approved and the foods are approved for varying levels of radiation based on the purpose. Irradiation does not make food radioactive. The safety of irradiated foods has been endorsed by the World Health Organization, the Centers for Disease Control, the U.S. Department of Agriculture and the Food and Drug Administration.

Irradiated foods now available in the U.S. include chicken packaged for restaurants and institutions, strawberries to increase shelf life, potatoes and onions to inhibit sprouting and fresh tropical fruits from Hawaii to eliminate the fruit fly. Some spices also are irradiated.

Retail food products are required to display the green radura symbol, a circle with a stylized flower design with the words "treated with radiation" or "treated by irradiation." Labeling is not required if only a minor ingredient of the food, such as a spice, has been irradiated.

Store, handle and cook irradiated foods in the same way as untreated foods. Foods can become recontaminated with disease-causing bacteria after irradiation.

For more information on irradiation of food, visit the web site www.eatright.org/airradi.html or the Centers for Disease Control and Prevention at www.cdc.gov. You can also call the CDC at (800) 311-3435.