For me, if I will need to check the masks then I will do this:-

1) blow candle test
2) water test
3) Cut to see number of layers against product claimed.
4) Burn test to check if the layers make out of cotton or paper, it should make with hydrophobic materials (normally out of plastic).

5) For N95/KF94/KN95, I will also check how easy to breath and if the mask expand or contracting when breathe in/out to check for good sealing.

Additionally info I'm known here, the packaging should not have FDA symbols as this prohibited by FDA. The packaging for medical device should also containing - manufacturer address, lot not, manufacturing date & exp date, perhaps also claimed tested standard, GB or ISO, etc

This post has been edited by muncheno: Sep 2 2021, 12:36 PM