image industrial radiography

Permissible cumulative doses of radiation

Although the subject of permissible cumulative dose of radiation is complex, the values given below apply to external irradiation of the whole body. The values have been established by the ICRP.

  • Radiology workers, category A: 20 mSv/year
  • Radiology workers, category B: 5 mSv/year
  • Public, not being radiology workers: 1 mSv/year

The whole body level of 20 mSv per year is normally interpolated as 0.4 mSv per week and 10 μSv/h at a 40 hr working week. These levels are acceptable but it is not to be automatically assumed that people working with radiation actually should receive these doses. When radiography is carried out in factories and on construction yards etc. special consideration is required for non-radiological workers and demarcation of the area in which radiation is used, and a maximum dose rate of 10 μSv/h applies, is essential. This is also the maximum value to be measured at the outside surface of a charged isotope container.