The Maximum Permissible Dose

• It is not possible to avoid some exposure to X-rays without discontinuing their use entirely, and the concept of the maximum permissible dose " has been introduced to denote an amount of irradiation which does not involve a greater risk to health than that encountered in many other walks of life.

• The maximum permissible doses may be defined as levels of irradiation of an individual, or part of an individual, exposed in the courses of his work, that are at present considered to be acceptable.

• Such doses should not be exceeded, and every effort should be made to keep the doses to the minimum level practicable.

• The actual amount of the maximum permissible does is reviewed and revised from time to time.

• At the time of writing the recommended annual whole body dose is 5 rem for designated radiation workers and 0.5 rem for the general public, while, if exposure is restricted to the hands, fore arms, feet and ankles, these amounts may be increased to 75 rem and 7.5 rem, respectively.