
Researchers found a way to clean N95 masks for reuse - lilbaine
https://www.washingtonpost.com/lifestyle/wellness/mask-n95-multicooker-covid/2020/08/14/94544304-dd8d-11ea-809e-b8be57ba616e_story.html
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jaredtn
Can anyone point me to data on the dangers of mask reuse? Masks block droplets
from entering, but it's unclear whether those droplets attach to the mask or
"bounce off". And if they attach, then it seems like those droplets would
eventually be displaced by others. It seems like whatever concentration of
particles is in the outside air would also become the concentration of
particles on your mask, and thus no more dangerous.

~~~
ksaj
According to a video I watched some time back, N95 works by statically
attracting the particles to stick to the fibers. Over time, the static
electricity is neutralized in the same way it is with, say, your laundry. This
is why you can't simply wash the mask, and also why they become ineffective
after a time of use, even if they never once come in contact with coronavirus
particles. Basically, your skin is gradually causing the static to discharge.

The video I was watching was about why N95 masks aren't interchangeable with
PM2.5 masks, and vice versa, but they can be (and are) combined for some
purposes. PM2.5 can let coronavirus through if it isn't in a medium large
enough to be filtered, and n95 can let some gases through that pm2.5 would
block. But noting that viral particles rarely fly around on their own (they
are usually in an aerosol liquid which may or may not have a surface area that
will be filtered by either one), the effectiveness isn't as drastically
different as it might initially seem when only talking about particle size.

The video argued that due to how the masks work, N95 is 95% effective, and
pm2.5 is 93% effective (and some argued 80-some-odd percent). PM2.5 can pretty
much be decontaminated with strong UV light, but N95 can't because no amount
of UV will make it statically charged again. Once discharged, an N95 is pretty
much toast, and cannot be re-used.

But, caveats be given, that is a single study and might not be representative
of "out there in the wild." It comes down to how much the charcoal filter and
other layers can hold onto versus how much the statically charged (and shorter
lived) N95 fibers last before being discharged. They have completely different
end-of-life profiles.

Also there are 2 parts to "effective" \- ingress air and egress breath. N95 is
quite a bit more effective at filtering your breath than PM2.5, which is
important when avoiding _you_ spreading the germs. This is the part a lot of
people get confused about, because it often sounds conflicting when reports
don't define what is "effective." The dangers of re-use also get confounded by
this detail.

------
refresher
Discussed earlier here
[https://news.ycombinator.com/item?id=24093044](https://news.ycombinator.com/item?id=24093044)

