But the FDA and the USDA have not demonstrated that the interventions they deem necessary can control all of the hazards they've specified. An increase in cost seems a likelier result of many of the federally proposed measures than an increase in food safety. The U.S. government is the only government in the world that has categorized irradiation as an additive and regulates it as such. Food irradiation does not add any substance whatsoever to food. Low to medium doses appear effective against foodborne protozoans such as Cyclospora cayetanesis .
High doses can significantly reduce foodborne viruses.
Foods that have undergone irradiation generally look fresh rather than processed, and they stay fresh longer than do unprocessed foods. Refrigeration is necessary or at least appropriate for most irradiated foods, as most are not sterile. Indeed, after many years of searching, no substance has been found in foods that have undergone irradiation that distinguishes them from foods that have not. Neither have any significant changes been detected in the foodborne microorganisms that survived the process. To minimize the risk of foodborne disease, irradiated foods are given to U.S. astronauts and to persons with malfunctioning immune systems.