- che food have been established upon the assumption that some- thing less than a dose that produces no apparent damage is an acceptable risk. For example, if X amount of radiation produces no apparent damage, acceptable risk. then 1/10 of X should be an Maximum permissible dose is defined by the International Commission on Radiological Protection as "that dose accumulated over a long period of time or resulting from a single exposure, which in light of present knowledge carries a negligible probability of severe somatic or genetic injury." The standards for body burden and for the concentration of radioisotopes in air, water and food that are used in this country are based upon recommendations made by the National Committee on Radiation Protection and Measurement and include recommendations by the International Commission on Radiological Protection, al Committee works closely. with whom the Nation- The recommendations have been published by the National Bureau of Standards, first in 1953 as Handbook 52 and later, in a revised and more conplete version, in 1959 as Handbook 69. Handbook 69 is, The title of "Maximum Permissible Body Burdens and Maximum Permissible Concentrations of Radionuclides in Air