Thread by @ghhughes

Do N95s and KN95s filter viruses?

Yes.

Here's an electron microscope image of salt particles on the fibes of a KN95 by @zhouliang_mask.

The image is of a NIOSH-type salt loading test of the melt blown filter media used in Zimi 9541.

The "big" crystals are about 1.5 microns. The smaller captured particles are as small viruses like Covid.

Covid virions are about .07 microns, are expelled into the air in larger respiratory droplets.

reddit.com/user/zhouliang…

If you are thinking, that's just salt, not viruses, not to worry. Scientists have tested N95s using real viruses using an international standard test called Viral Filtration Efficency (VFE). N95s filter viruses extremely well.

x.com/search?q=n95s%…

N95s can filter extremely small particles thanks to multiple mechanisms, including electrostatic attraction.

This video does a great job of how N95 filter media works to filter a wide range of particles.

Whether you think you need N95s or not, now is a good time to stock up on them. You want them on hand *before* there is a rush to buy them, like in wild fire season or another pandemic. They can last for years in storage and still perform well.

netec.org/2020/03/05/nio…

You'll get the best protection from masks that seal well to your face to keep unfiltered air out of the mask. You may have to try a few different models to find one that fits you well.

@zhouliang_mask "on the *fibers* of a KN95"

Well, I guess the typos show my post isn't AI 😅