There are a few ways you can express this. After a quick search in the Lexicon Morganianum for "mask," I found "persona oxygenica" as "oxygen mask," "oris tegmen adversus gasium" as a literal way to express "gas mask," and "masca antigasalis" as a neologism for gas mask. I also did a quick search through Ephemeris, the news website in Latin, which found "de mascis ori" which seems to mean face mask.
So, I think that you can use persona, masca, or oris tegmen to mean "mask" in the PPE sense. You might want to elaborate on them with masca ori instead of just masca. You might also want to use an adjective such as the medieval latin word protectivus, which is used in entries in the Lexicon Moranianum, to be clearer; thus persona protectiva, masca protectiva, or even oris tegmen protectivus.
You gave the example of a surgical mask. You could express this with the adjective "chirurgicus -a -um." This would make terms such as masca chirurgica or persona chirurgica.
Hope this helps.