During irradiation, foods are exposed briefly to a radiant energy source such as gamma rays or electron beams within a shielded facility. Irradiation is not a substitute for proper food manufacturing and handling procedures. But the process, especially when used to treat meat and poultry products, can kill harmful bacteria, greatly reducing potential hazards.
The agency determined that the process is safe and effective in decreasing or eliminating harmful bacteria. Irradiation also reduces spoilage bacteria, insects and parasites, and in certain fruits and vegetables it inhibits sprouting and delays ripening. For example, irradiated strawberries stay unspoiled up to three weeks, versus three to five days for untreated berries.
Irradiation does not make foods radioactive, just as an airport luggage scanner does not make luggage radioactive. Nor does it cause harmful chemical changes. The process may cause a small loss of nutrients but no more so than with other processing methods such as cooking, canning, or heat pasteurization. Federal rules require irradiated foods to be labeled as such to distinguish them from non-irradiated foods.
Research dating to the 1950s has revealed a wide range of problems in animals that ate irradiated food, including premature death, a rare form of cancer, reproductive dysfunction, chromosomal abnormalities, liver damage, low weight gain and vitamin deficiencies.
Irradiation destroys vitamins, essential fatty acids and other nutrients in food -- sometimes significantly. The process destroys 80 percent of vitamin A in eggs.
Irradiation disrupts the chemical composition of everything in its path -- not just harmful bacteria, which the food industry often asserts. Scores of new chemicals called "radiolytic products" are formed by irradiation -- chemicals that do not naturally occur in food and that the FDA has never studied for safety.
To date, in Australia and New Zealand, only herbs and spices, herbal teas and some tropical fruits have been approved to be irradiated.