[Paul R.]

Has anyone seen anything on whether it is possible to disinfect a N95 mask and re-use it?

I have, of all things, a small supply of carbon tetrachloride that my Dad gave me before it’s sale was pretty much banned. I’d think the fumes from that stuff would kill most anything... But would they degrade some material in the mask?

Alternately, does brief soaking in 70% rubbing alcohol or hydrogen peroxide disintegrate or degrade a N95 mask?

Other ideas? Please cite reliable sources.

Thanks!

[Pollard]

I’ve got an N95 dust mask and I soaked it in some purple degreaser and hands washed/swished it and it held up fine so it would have held up fine to Lysol too.

[PA Engineer]

Has anyone seen anything on whether it is possible to disinfect a N95 mask and re-use it?

Yes. 65C for 15 minutes. The masks can be reused, however will become harder to breath out of due to particulate clogging. The temperature and time is based on MERs studies.

If you have an electric oven you can set it to that temperature. A spa sterilizer can do the same. The prices have gone up.

Soiiw CH-360T Heat Sterilizer 300W 1.5L w/Timer Disinfection Box Manicure Pedicure SPA Salon Equipment for Sundry Beauty Hair Nail Metal Tools with Handle

I'm not comfortable with strictly UVC sterilizers because of depth of treatment.

Best.

[blueplum]

This is about it, Paul:

Method and results:
Oven dry heat disinfection - 70C (160f) for 30 min
Hair Dryer disinfection - 56C (133F) for 30 min
Alcohol spraying disinfection - degrades filtration below 95
Steamer wet heat disinfection - degrades filtration below 95
High temperature and high-pressure disinfection - distorts
Ultraviolet disinfection - unknown how effective

https://www.thebeijinger.com/blog/2020/02/18/how-reuse-and-dispose-your-masks-safely

https://mp.weixin.qq.com/s/3QYVWO4kj5qwuSHnhcM9uQ

and,
This video is for demonstration purposes only and not recommended. It’s an experiment by a Los Alamos Brainiac and simulates a viral load on outside of mask before and after washing. Could be a method to use to keep the inside of a healthy person’s mask clean of breath bacteria colonies. Like if the mask is used while walking the dog or briefly out to get the mail and might see a neighbor. But, as above, the mask filtering could be reduced. Washed masks should never be used in a red zone.

https://www.youtube.com/watch?v=PGHMU4iegLE

The N95 mask is made of a polypropylene blown fiber. The ‘surgery’ mask is made of three layers - the inner, absorbent layer (to absorb respiratory moisture), the outer water-resistant layer (to prevent droplets from seeping thru) and the trap layer, to trap the little viral buggers that get thru the water-resistant layer. If a mask has not been contaminated, dirt on the front and inside can be scrubbed with a toothbrush and very hot soapy water, then rinsed in hot water and hung to dry outside in the sun.