Here's some interesting info. I'm not advocating the brand just the educational info. There's been a lot of misinformation about masks, even by our government.
https://www.halyardhealth.com/indus...ing-the-right-face-mask-3-things-to-know.aspx
I think this article has it down pat when they mention
Procedural masks, also called surgical masks. Those are masks that you don when you don't want to breathe germs on a table full of sterile tools or the area on the patient they want to keep as sterile as possible. My experience is bedside procedures, & Isolation rooms, not OR.
But, there isn't a one-way material in the masks. It protects both ways, just not as fully.
I wish I had N-95 NIOSH fit-tested masks but I don't. I have one R-95 that is like an N-95 except it filters out oil in the air. :surprise: Much thicker & it's
hard to breathe thru. So, I have surgical masks, too. I swear they were made for people with flat faces! They hurt my nose & it isn't big.
I was buying electronics at WalMart. A very intelligent young guy works there. I asked him why he has the loops of the mask twisted & he said it makes it easier to breathe. I said, yes, I can see it makes it gap at the sides which lets more air in. . .:vs_bulb: Like I wrote, he's very intelligent, but, just hadn't realized what he was doing. I feel for them; they really aren't used to working 8 hrs with a mask on. Plus, good hospitals have very filtered air which doesn't have all the fuzz that a place like WalMart does. That's what gets to me, making me adjust my mask. I can only carry a small bottle of hand-sanitizer, so I can clean my hand each time I adjust my mask.