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I came across the following as I continue to research the best way to disinfect my limited supply of N95 masks.

https://www.sages.org/n-95-re-use-instructions/

Above link is for a simple explanation and ideas. The link below is more detailed.

The above link (interview with the inventor of the N95 mask) says the best way is to rotate masks every 3 to 4 days leaving them to air dry. Even with one or two masks that might be doable with our stay-at-home restrictions. Before I read this I was thinking 24 hours would be good (similar to cardboard) but didn't realize the inside filter was more like a plastic (poly synthetic).

He says the 2nd best option is to heat them to 150 degrees for 30 minutes in your oven. Suspend them using a wooden clothes pin so none of the mask is touching metal. I was putting my mail in the toaster oven at 170 for 15 minutes based on other studies of MERS as per PA Engineer's research. I don't know - maybe I'll go at 160 for 30 minutes just to be safe. Even on the second paper below, talking with the same guy, they say 160 for 30 min instead of 150.

In the following article and I've read elsewhere:

https://utrf.tennessee.edu/information-faqs-performance-protection-sterilization-of-masks-against-covid-19/

The use of UV light will degrade the synthetic poly material that makes up the inner filter. But they aren't sure how long it would take to degrade it. I have been putting my masks under a UVC light - I guess I will stop doing that and hope that I haven't degraded them yet.

I had one mask that I left in the trunk of my car along with my groceries and other stuff. I run the Ozone generator (100 cubic/ft-m, 7700 mg/hr) for 45 minutes which is probably overkill. It destroyed the elastic on one of my masks. This longer paper also talks about steam and boiling - but I wonder if the boiling is for regular surgical masks???

Ping to post 565 for recent interview and paper with inventor of N95 masks on best ways to disinfect them. (Two of my ways perhaps weren’t the best.)

Oh - for the degraded or used-up elastic bands - I bought a big bag of rubber bands at Staples.

I'm using the sterilizer now that I posted from Amazon.

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

Simple and works well. I upped the time and slightly the temp based on the second paper. Abundance of caution.

Wife has to change out regularly on her one week on (one week off - telemedicine) at the hospital. They still don't have adequate supplies. They are however suppose to provide surgical for the patients during the visits this week. We'll see.

I believe the masks will become too hard to breath with before the elastic is damaged. The sterilizer I included has both UVC and heat. So far no problem.

We are keeping it in the garage and isolated from the house. I was uncomfortable using the oven just because of potential cross contamination.

I suspect the next advice will be for everyone to wear masks when out as soon as they are available.

YMMV. Best. Thanks for the ping.

Don’t UV sterilize the inner mask. Sterilize only the outer mask. Go for the greatest concentration of virus, which is always the outer layer, while minimizing damage to the mask.

“The above link (interview with the inventor of the N95 mask) says the best way is to rotate masks every 3 to 4 days leaving them to air dry.”

I was thinking of exactly the same 24 hours, but 3 to 4 days works for me. And, actually, the very low mask usage and exposure to viral loads, due to not having to go to 6 Big Boxes every day looking for toilet paper (as the FluBros have to do), means that our masks capture very few virons in the first place. Given that, I suspect the viral load after 24 hours will be nil.