Derived air concentration

The DAC is the activity concentration in air in Bq m-3 of the radionuclide considered that would lead to intake of an annual limit on intake (ALI) assuming a sex-averaged breathing rate of 1.1 m3 h-1 and an annual working time of 2000 h. DAC is given by:

$DAC_j = \frac{ALI_j}{2200}$

The Commission does not recommend the use of DAC because it considers that for compliance with dose limits it is the total dose from external radiation as well as from intakes of radionuclides that must be taken into account.