The U.S. Food and Drug Administration (FDA) has issued a final rule that amends the regulations for “irradiation of animal feed and pet food to provide for the safe use of electron beam and x-ray sources for irradiation of poultry feed and poultry feed ingredients.” The revised rule states that ionizing radiation is limited to (i) “gamma rays from sealed units of cobalt-60 or cesium-137”; (ii) “electrons generated from machine sources at energy levels not to exceed 10 million electron volts”; (iii) “x-rays generated from machine sources at energies not to exceed 5 million electron volts”; and (iv) “x-rays generated from machine sources using tantalum or gold as the target material and using energies not to exceed 7.5 (MeV).” See Federal Register, May 10, 2013.