
3M does not recommend attempts to sanitize, disinfect, or sterilize N95 masks [pdf] - bookofjoe
https://www.apsf.org/wp-content/uploads/news-updates/2020/Disinfection-of-3M-Filtering-Facepiece-Respirators.pdf
======
giardini
Of course they don't - there is no upside to tell people to do so. If it
fails, 3M could be sued; if it works, 3M would lose sales.

That said, if you don't have any other mask, I fail to see how viral material
can survive a soak in alcohol for a few minutes and then drying overnight in a
warm spot away from flames (alcohol is flammable).

But see _" Disposable N95 Masks Can Be Decontaminated, Researchers Confirm"_:

[https://www.nytimes.com/2020/04/16/health/n95-masks-
decontam...](https://www.nytimes.com/2020/04/16/health/n95-masks-
decontaminated-coronavirus.html)

~~~
jxramos
> We concluded that 75% alcohol solution and chlorine-based solutions were
> detrimental to the static charge in our meltblown fabric, and resulted in
> reduced efficiency.
> [https://stanfordmedicine.app.box.com/v/covid19-PPE-1-2](https://stanfordmedicine.app.box.com/v/covid19-PPE-1-2)

~~~
mc32
How does ozone fare in eliminating the threat but not degrading the material?

~~~
rckoepke
I'd assume it would degrade N95 masks. Ozone reacts at least somewhat with
both polyethylene and polypropylene at relatively low temperatures and short
timelines. This paper shows effects at 95F and 15-90 minute exposures:
[https://sci-hub.tw/10.1163/156856195X01012](https://sci-
hub.tw/10.1163/156856195X01012)

------
maxfan8
For all the cynical comments here, 3M has published guidance on sanitizing and
disinfecting half and full facepiece respirators:

[https://multimedia.3m.com/mws/media/1793959O/cleaning-and-
di...](https://multimedia.3m.com/mws/media/1793959O/cleaning-and-
disinfecting-3m-reusable-respirators-following-potential-exposure-to-
coronaviruses.pdf)

Note that TCID and some other specialty treatment centers (TCID solely treats
TB I believe) have been doing this for a while (although not necessarily with
3M masks).

Source:
[https://www.ncbi.nlm.nih.gov/books/NBK540078/](https://www.ncbi.nlm.nih.gov/books/NBK540078/)

------
shard
According to WebMD, COVID-19 can live up to 5 days on various materials
([https://www.webmd.com/lung/how-long-covid-19-lives-on-
surfac...](https://www.webmd.com/lung/how-long-covid-19-lives-on-surfaces)).
Why not just have a rotation of 6~7 masks where every mask that can be reused
is left in a clean location for over 5 days so no sterilization is needed?

~~~
teruakohatu
Does anyone know the source of that research, I am very surprised they are
claiming 4 days on wood.

Results published earlier this month showed no detectable virus on wood after
two days, and additionally found non-flat surfaces, like wood, to be more
resistant. It seems unlikely that the virus will last 4 days on outdoor
decking as WebMD claims.

[https://www.thelancet.com/journals/lanmic/article/PIIS2666-5...](https://www.thelancet.com/journals/lanmic/article/PIIS2666-5247\(20\)30003-3/fulltext)

------
giardini
FWIW some CPAP machines use ozone in their cleaning cycle. One might be able
to jury-rig the CPAP to cycle ozone through the mask during that period.

------
rasz
HP does not recommend refilling ink cartridges. Coca Cola does not recommend
reusing plastic water bottles with tap water.

------
ohiovr
Has anyone tried dry cleaning the masks? Its a pretty tough solvent and
viruses are made partially of fatty acids.

------
ohiovr
PH, reducing agents, radiation, heat have been tried. Would adding pressure do
anything?

------
ptrenko
I just hang it. Does that work?

~~~
woofie11
No. It has two problems:

* COVID19 isn't the only threat. Other germs can multiply with time. This is not the time to go to a hospital with an infection.

* When I last looked, there was preliminary evidence COVID itself survives surprisingly long in a mask (I think days)

~~~
ptrenko
Okay so I'll hang it then. Brain overloading.

~~~
woofie11
If you're taking an N95 out-of-rotation, you might as well follow best-
practice: Dry heat. 30 minutes. 75-95C. They're a scarce resource.

It's annoying to see them going to people who don't use them right (a
Republican senator was wearing one upside down). Incorrectly used, they're no
better than a surgical mask.

