Can irradiation make food radioactive?
No. Food does not come in contact with radioactive material during food irradiation, and cannot be contaminated this way. Radiation that is too energetic, however, can disrupt the energy balance in the nuclei of food atoms, making them unstable (radioactive). This is known as induced radioactivity. Electron and x-ray beams can be energetic enough to induce radioactivity. To prevent induced radioactivity, FDA limits the energy of the radiation from these sources to less than 4 mega-electron volts. Radiation from cobalt-60 sources is not energetic enough to induce radioactivity.