Here is something I read (on the internet so it must be true)

 

This actually jives with my knowledge base as it pertains to N95 and above masks (N99, N100, P100 , R95, R100 and so on.

I think my last day at work (due to being High Risk) was 3 or 4 weeks ago. Prior to that I was by design and circumstances, the de facto expert on masks. They were in my department and I read everything I could Every DAY so as to be able to speak with some certainty.

I can recite if called upon, the difference between N, R, and P masks. As well as the differences between 95, 99, 100. I can tell you the difference between N95 masks, and "surgical masks" I can also tell you why the dust masks, bandanas, and home made masks are NOT sufficient for "Virus" mitigation.

Masks (N95 and beyond) are certified by NIOSH. NO others are certified to filter down to .3 microns. PERIOD

We carried a "surgical mask" made by Safe Life They has applied for and were granted N95 certification (primarily because of their 3 layer including active antimicrobial based on iodine)

Can they *Help*? Well that depends on several things, FIT is a big one, but that is NOT enough. To illustrate this point, imagine a mask made entirely of sticky Duct Tape.

Arguably 100 percent effective (as is super glue)

 

There is a measurable down side (asphyxiation comes to mind)

Here's the article
<SNIP>
added the warning a homemade mask is just 2-3% effective against stopping airborne virus particles, as woven cloth masks allow in 97% of viral particles,
"That means almost no protection for the wearer at all," wrote. "Wearing a homemade cotton mask is a false assurance, explains epidemiologist May Chu. She says it will block only about 2% of airflow."

 <SNIP>