Best type of mask for COVID?

[Alfred001]

I was under the impression the N95 masks are the best, but recently I heard from someone (who tends to be knowledgeable about these things, but, of course, not beyond scrutiny) that the masks with the filters/valves on them are the best. Is there any science that settles the question of which type of mask provides the best protection?

There's a table giving stats for various types of masks here, but I can't really make heads or tails of these metrics, maybe someone can explain. Flow rate? Inhalation and exhalation resistance? Is more or less better? etc.

EDIT: I see now that both the N95 and the european FFP2 come in valve and valveless varities. Anyone know how they differ in performance? Is an N95 with a valve better than one without it?

EDIT #2: Apparently, there is a higher standard yet FFP3/N99/EN149/P3 (different name in different regions). I'm still wondering whether valved or valveless varieties are better, assuming this higher standard has them, as well.

Edited November 5, 2021 by Alfred001

[CharonY]

Exhale valves are *bad*. If you are unknowingly infected, it allows you to freely spread the virus around. N95 masks without valves but worn tightly, i.e. air enters and escapes exclusively through the material work very well to reduce risk.

[Janus]

Masks serve a dual purpose:  Protection of the user from others who may be infected, and protection of others from the user if he/she is infected.

And of the two, they are more effective with the later.  Valves in the mask work to defeat this by allowing more water droplets to escape the mask.

 

People need to to stop thinking of masks in terms of something they wear to "just protect themselves",  and more as something  that we, as a community, should wear to protect each other.

[geordief]

Not sure how good it is as a practice  but I wear a cheap surgical mask  under a reusable mask 

I think that  gives a tighter fit  and keeps the surgical mask clean.

 

I only wear it for going to  the shops and am not sure if it would be comfortable to wear continuously for hours at a time .

 

I keep the surgical mask going until it gets dirty.