COVID-19: If You Are Lucky Enough to have an N95 or N100/P100 Particulate Respirator Mask, It Must SEAL to be Effective
At the grocery store two days ago, I saw two employees there, both bearded, wearing cheap masks badly fitted with air leaking in from virtually every side of the mask. Everything was wrong with that; it was a parody of mask usage, a poster for how NOT to use a mask:
- A bearded face makes it IMPOSSIBLE to seal the mask against the face—the face MUST be freshly shaven.
- Seal around nose and face MUST be there or air just leaks in.
- Straps must be tight enough to reduce chance of breaking the seal when smiling, grimacing, whatever (those masks with straps around only the ears are a total joke and cannot ever work properly).
- Poor quality mask, but maybe better than nothing if fitted properly.
If not fully sealed, the particulate respirator mask will have some partial value depending on the amount of leakage. Pay attention to at least trying to do it right—it’s not simple or fast without practice. Also some faces are too small or too large for standard mask sizes.
Roger Cicala (medical background) at LensRentals.com states that “bitrex or isoamyl acetate test” should be used to validate sealing (these substances are unpleasant to breathe and thus show leakage or not). But I doubt that most of us have any such stuff sitting around!
So.... do your best to make sure there is no leakage. I know from experience that I have very good sealing from usage in fine smoke, heavy pollen, dust, etc, but I have no way of knowing if my N100 mask is sealing perfectly at all times. I just know that when I take it off, I quickly have bronchospasms under conditions of pollen, dust, smoke, etc.
And I do have to take off an N100 mask at about 7000' elevation on up during double centuriesbecause my unusually large lung capacity and high VO2 mask start to collapse the mask as my lungs pull in huge quantities of air. In one instance, I had to use my inhaler a dozen times in 5 hours as a result of pollen after no longer being able to use the N100 mask (vs 4 times a day as normal treatment). So clearly the N100 particulate respirator was getting most of it.
Finally, even a handkerchief will keep someone’s cough from directly landing on your face and that might have some value, but better just to maintain 3 meter distance (6 feet is the official minimum). Just keep in mind that hands touching things are probably a much more concerning transmission vector.
Full disclosure: when I shopped for groceries, I did not wear a mask. I just kept my distance, and sized up anyone and listened for coughing. This is good enough for groceries so far and I trust on maintaining distance as most of us must, taking a small risk once every 7-10 days for 10-15 minutes to resupply.