Incidentally, if you buy 3M masks, there's a number on the bottom of the box that can be validated on 3M's web site.[1] They will tell you if that's a valid number and if anyone tried to validate that number before.

[1] https://safeguard.3m.com/Guest#/Validation

Count your masks. My box of 10 3M masks (closed not taped shut) from Home depot only had 9 in it.

The told me I can gladly travel 30 min back to the store and wait in line for a refund. No thanks.