sycamore
No offense taken, but I, and I think kimoki, was talking about the quick access inflatable masks that are fitted to most of the new large jets 777's 767's etc. (not the old plastic things that hang over the back of the seat, as fitted to some of the old DC10's)
These are difficult to restow correctly (if you get it wrong the O2 leaks)
At the moment it is not SOP to use them as a precaution, if you start to use them on a regular basis then they will need to be correctly disinfected and restowed correctly at the end of each sector.