Previous studies on the evaluation of irritant species from burning cables in a modified prEN 50399 fire test produced FEC/FED values based on ISO TS 13571. However, the ISO standard mentions in its scope that these indices can only be used within e.g. modelling. The results show that the developed methodology allows evaluation of critical evacuation conditions based on not only temperature and visibility, but also on gas composition of the smoke. When comparing the two cables it can be seen that cable M creates critical conditions for some of the occupants during evacuation for the chosen design fire when the production of irritant gases (HCl, acreolein, Formaldehydes) is considered. In practice, this means that the fire safety engineer needs to find other solutions by either choosing other cables or other active systems (e.g. additional roof venting).