Orientation guide for laser safety standard users

The task of extracting the appropriate assessment conditions for classification can be rather challenging. The safety philosophies of the different laser classes are dedicated to address several worst case use conditions. Virtually, there are up to seven laser classes available. Four of them, where the safety philosophy comprises optically aided viewing, would even require two different assessment conditions (Conditions 1 and 2 in terms of IEC 60825-1). At which Condition 1 is intended to situations where telescopes etc. may increase the hazard whereas Condition 2 addresses the use of microscopes or eye loupes etc. For each of these two conditions even two different assessment conditions are specified further on, separating between “default” and “complete”. In case of doubt, “ … The most restrictive of the applicable measurement conditions shall be applied. If the most restrictive condition is not obvious, each applicable condition shall be evaluated… ”. The remaining Condition 3 applies to the unaided eye (i.e. classification into the two “M-classes”), for scanned laser radiation and for MPE-related worst case-evaluations. The present contribution tries to provide guidance for a quick selection of the applicable assessment conditions based on the fundamental data of the laser under consideration.