Dose value of an ionizing radiation fixed by the legislator as a maximum to which a person may be exposed based on recommendations from scientific committees. Different dose limit values are fixed for different groups of persons. When handling radioactive substances and ionizing radiation the principle that any unnecessary radiation exposure is to be avoided must be observed and if unavoidable it is to be kept as low as possible, even when within the legal limit values. The German Radiation Protection Ordinance and the X-Ray Ordinance fixes the limit values for occupationally exposed persons as listed in the table. Lower values apply for occupationally exposed pregnant women and apprentices.

Tissue or organ

Limit

Effektive dose

20 mSv/year

Organ dose:

Bone marrow (red), gonads, uterus

50mSv/year

Adrenals, bladder, brain, breast, lens of the eye, small intestine, upper large intestine, kidney, liver, lung, muscle, oesophagus, pancreas, spleen, stomach, thymus

150 mSv/year

Bone surface, thyroid

300 mSv/year

Ankles, feet, forearms, hands, skin

500 mSv/year

Dose limits for occupationally exposed persons

The effective dose for members of the public must not exceed 1 mSv/year. The limit for the lens of the eye is 15 mSv/year and for the skin 50 mSv/year. The party responsible for radiation protection is required to plan the technical rating and operation of nuclear plants such that the following limit values are not exceeded by radioactive emissions with exhaust air or waste water:

Effective dose and dose for gonads, uterus, red bone marrow

0.3 mSv/year

Dose for adrenals, bladder, brain, breast, small intestine, upper large intestine, kidney, liver, lung, muscle, oesophagus, pancreas, spleen, stomach, thyroid, thymus

0.9 mSv/year

Dose for bone surface, skin

1.8 mSv/year

These dose limits shall be observed at the most unfavourable point of effect, taking account of all relevant load paths, the dietary and lifestyle habits of the reference person in addition to any possible prior contamination by other plants and facilities.