If you want to be sure the mask fits correctly you can simulate the procedure here which is basically wearing the mask with a larger plastic bag/enclosure over

If you want to be sure the mask fits correctly you can simulate the procedure here which is basically wearing the mask with a larger plastic bag/enclosure over you and having some spray a aerosolized bitter compound in the air around your head [pdf]: http://www.kdheks.gov/cphp/download/Fit_Test_Pro_for_N95_R.pdf http://www.kdheks.gov/cphp/download/Fit_Test_Pro_for_N95_R.p... This is how you get fit tested in hospitals. I'll also add that n95 masks are considered overkill for influenza (but not SARS, TB, measles, varicella aka chickenpox). Also, get your flu shot every year! Even if it isn't optimized against the antigens on this years virus it is like a brick in a wall your immune system builds up over time against a variety of influenza variations.