The employer shall identify any zone where workers are likely to be exposed to levels of ionising radiation exceeding:
1° For the whole body, assessed on the basis of the effective dose: 0.08 millisieverts per month;
2° For the extremities or the skin, assessed on the basis of the equivalent dose: 4 millisieverts per month;
3° For the concentration of radon activity in the air, assessed on the basis of the effective dose: 6 millisieverts per year.
The assessment of the exposure levels used to identify these zones is carried out by taking into account the aspects mentioned in 2°, 3°, 8° and 9° of Article R. 4451-14 and considering the permanently occupied workplace.