I will only post ONCE about masks on this thread. I'm only giving info because I've seen wrong recommendations about N95 posted, not debating on whether or not a teacher should wear a N95 or not.
If you decide to wear a N95 mask, remember it has to be your fit. For that you need to be
fit-tested and buy the right N95 model. If your N95 is not a good fit (no way to know unless you get fit-tested), your mask probably won't protect you more than a level 1 or even a non-medical mask (or offers no protection at all). N95 are
DISPOSABLE! That means one use only. I know some hospitals are testing ways to disinfect N95 masks to re-use them when stocks are low but right now, to my knowledge, these methods are not approved by Health Canada and I don't see how someone can do it safely from home. If you want a re-usable N95 level 'mask', you need to get a reusable respirator.
https://www.3mcanada.ca/3M/en_CA/wo.../respiratory-protection/reusable-respirators/