Myles,
Not knowing the context of your question, let me just give a little info on the terms as I have seen them used. Traditionally, that is.
I was taught that a safety copy should be intercuttable with the master, so if the master was damaged it could be repaired by inserting a small section from the safety copy. This means, of course, that it's a flat copy, same speed, level and EQ curve as the master. Anything else--EQ copy, leveled copy, different curve for export, Dolby when the master wasn't, non-Dolby when the master was--would not qualify as a safety copy.