Dose limits help ensure that no person is exposed to an excessive amount of ionising radiation in normal, planned situations.
They are the strongest form of restriction on dose to an individual. Exceeding a dose limit is contrary to regulations in most countries.
Dose Limits Recommended by ICRP
Dose limits alone are not enough to ensure adequate protection. They function in combination with the fundamental principles of justification and optmisation.
These limits apply only to doses received above the normal local natural background radiation.
Dose limits apply only in planned exposure situations. In other situations, restrictions on individual dose are called reference levels. They provide the additional flexibility needed in emergency and existing exposure situations to make sure protection is optimised.
Dose limits do not apply to medical exposures. If they did, the effectiveness of diagnosis or treatment might be reduced, doing more harm than good for the patient. The emphasis is on justification of medical procedures and optimisation of protection.
▶ Further Reading: Quotes from ICRP Publications ▼ Further Reading: Quotes from ICRP Publications
Publication 103 paragraph 243
Dose limits apply only in planned exposure situations but not to medical exposures of patients. ... dose limits ... recommended in Publication 60 ... continue to provide an appropriate level of protection. ... Within a category of exposure, occupational or public, dose limits apply to the sum of exposures from sources related to practices that are already justified ...
Publication 103 paragraph 247
Dose limits do not apply in emergency exposure situations where an informed, exposed individual is engaged in volunteered life-saving actions or is attempting to prevent a catastrophic situation. For informed volunteers undertaking urgent rescue operations, the normal dose restriction may be relaxed ...
Publication 103 paragraph 248
For informed individuals of the general public involved in caring and comforting patients released from a hospital following therapy with unsealed radionuclides, the normal dose restriction may be relaxed and such individuals should in general not be subject to the public dose limit ...
Publication 103 paragraph 186
... Once an employer has been notified of a pregnancy, additional protection of the embryo/fetus should be considered. The working conditions of a pregnant worker, after declaration of pregnancy, should be such as to ensure that the additional dose to the embryo/fetus would not exceed about 1 mSv during the remainder of the pregnancy ...