In the UK, the national guidance is to use a dose constraint of 0.3mSv pa for areas adjacent to X-ray equipment that non radiation workers or members of the public might access. In applying this constraint, we are allowed to take the likely occupancy of the adjacent areas into consideration.
In preparing the guidelines for CBCT, it would be useful to know what dose constraints are required in other EU countries. Please can you let us know what your national requirements are?
International Commission on Radiological Protection (ICRP) also suggests that for the control of public exposure an appropriate value for the dose constraint is 0.3 mSv in a year.