The main issue, as raised already by Tony Colgan, is that with regard to radon in workplaces the recommendation is not in line with the adopted international standards nor with the draft Euratom standards; while the responsibility for health and safety at work is with the employer, radon at work is included in the definition of occupational exposure; hence, amongst other, the dose limit should apply. In line with the overall graded approach to regulation, one may define a dose threshold for the application of certain requirements in occupational exposure, similar to the distinction between categories of workers A and B in the Euratom BSS; such a threshold should not be regarded as a reference level however. In general, the reference level in workplaces should be the same as in other types of buildings; some countries may nevertheless prefer to have a somewhat higher reference level (in radon concentration) in workplaces compared to dwellings, in order to limit the burden of regulatory control. It is not useful to have two reference levels, one in radon concentration and one in dose, for the same exposure situation.