[doodlebugging]

One of the first articles that I read mentioned the use of autoclaves, essentially steamers used for sterilizing surgical tools, etc. I think it was a NIOSH article. These are already in use in hospitals.

That led me to the article I linked about using microwaves. Microwave ovens excite water molecules to cook and the creation of steam from the cooking process should kill the pathogens.

I have family members who need some protection from this threat and that is why I went down this rabbit hole in the first place.

Based on everything I read I am comfortable concluding that masks can be reused if they are sanitized by microwaving with a small amount of water to create steam.

The methods tested in the paper appear to show effectiveness that maintains N95 rating and kills pathogens in the process.

I am not a doctor and in fact I spend too much of my time trying to avoid ever seeing one.

Perhaps you or someone else out there can recreate these tests or conduct similar tests to determine whether this is viable.

[mattkrause]

An autoclave is more like a pressure cooker than a steamer.

You need temperatures well in excess of 100 degrees Celsius to reliably kill everything, especially bacterial spores (which, admittedly, are not the major issue here).

To do so, autoclave use high pressure steam (121C at 15 psi) for long enough that everything reaches that temperature. A microwave won’t even get close to that, though it can disinfect, rather the sterilize, just like boiling water can. You also need to be careful that the entire object gets heat-treated; home microwaves often have hot and cold spots and one missed spot can spoil everything.

This stuff is fairly complicated and I’d encourage you stick with established methods if you can, which I think is currently treatment with a UVC lamp.

[doodlebugging]

Thanks for the information. I agree that home microwaves heat unevenly but I think that is one of the reasons that the authors in the article went with bagging the masks. The steam would be trapped in the bags and the masks would get treatment at a more consistent temperature making the process more effective at killing the pathogens.

I think that microwaving the masks accomplishes the task using tools that an ordinary person may already have on hand and tools which require almost no training. UV sterilization is complicated by the need to avoid exposure to UV light and the fact that most people don't have a suitable UV lamp available. Hospitals may already have those tools on hand and in that case they probably have trained users who can disinfect masks with them. That seems to be the best way for them to reuse masks.