a. The protection limits and predicted exposure used to determine the achieved RDM for biological effects shall be defined in terms of one or more of the following variables:
1. effective dose;
2. organ equivalent dose;
3. ambient dose equivalent;
4. directional dose equivalent;
5. personal dose equivalent.
NOTE 1 For requirements on radiation effects in biological material, see Clause 11. For background on limit exposure policies of the different Space Agencies, see ECSS-E-HB-10-12 Section 10.4.4.
NOTE 2 For interplanetary missions, exposure limits are not currently defined.