You cannot just put on any old N-95 mask and expect it to provide ANY protection unless you have been professionally FIT TESTED to determine which brand and size mask fits YOUR face, and you are instructed how to properly adjust and wear the mask.
I have done this testing for many years in a hospital.
Here is a video of what’s involved. If ANY leak occurs while you wear it, it fails to protect you.
https://m.youtube.com/watch?v=xl4qX6qEYXU
And, fit testing is a serious issue.
https://www.reliasmedia.com/articles...95-respirators