Mask questions

[cos]

Considering only their effectiveness at a) slowing the spread of covid-19 and b) protecting you from covid-19, in public and grocery stores and similar (that is, I'm not asking about bacteria, fungus, healthcare settings, etc.)...

• If an N95 mask doesn't quite fit as tightly as it should, is it still significantly better than all surgical & cloth masks? Or does the imperfect make it likely not much better than a surgical mask?

• I've seen it claimed that multi-layer cloth masks are better than actual approved surgical masks. I'm very skeptical. But is there some validity to this claim?

• Is there any difference between US N95 masks and Chinese KN95 masks for this purpose? Other than the fact that I've never figured out how to actually fit a KN95 to my face :) But aside from the fit, are they effectively exactly the same thing (for this purpose)?

If you have helpful references or sources for answers to any of these questions, I'd like to read!

Comments

[elusiveat]

My perspective is based on intuition and personal observation, not science.

On your first question, there are different ways of not fitting quite as tightly as it should. If you can get a good seal on the inhalation but some slight venting at the edges during exhalation, I think an N95 might still be worthwhile. As I understand it, the real selling point of the N95 is that it provides effective filtration of tiny particles on inhalation, and I haven't actually heard of anything else that does this.

On the other hand, if you're not getting a good seal on inhalation, I think a fabric mask with a better seal would be preferable.

One of my friends has spoken favorably of this product https://www.fixthemask.com/, which fits on over a mask to improve the seal, so that might be something worth looking into. The site shows it being worn over surgical masks but I think my friend was talking about using it with meltblown masks that are not N95s.