Reusing masks

Up until very recently, I have not been able to get any face masks and hence have not entered any public place such as a store. Last week, my daughter mailed me a few and so I was able to go to the local Asian grocery store and buy stuff that was running low. Some stores no longer allow you in without a face covering. Since I had a limited supply, I had wondered about the advisability of reusing face masks that were supposed to be disposable. While the recommendation is that one should not reuse them, it seemed wasteful since it would consume items that should be saved for people like health care workers who need them on a daily basis and need to shed them frequently

Since germs cannot live for long outside of a living host, I felt that if one was an occasional user and kept a used mask in a dry, sunny place for a couple of days after each use, it should be possible to reuse them unless they had a tear or something, since the germs would be dead. But I could not find anything to this effect until I recently came across this NPR interview with Joshua Santarpia of the University of Nebraska Medical Center who says that we have to come to terms with reusing masks and that there may be ways to do it at least somewhat safely.

“It’s become a thing that we have to do. It is never something I would have ever recommended before. And in the early days of the outbreak, it hurt me both to throw them away at the end of an activity and also to keep them because the last thing I want to do is keep that thing around because it’s dirty. You know, the idea is you’re done with your shift. You take it off. You throw it away. That was how they were developed. Now, mask reuse – there’s data out there that suggests that, you know, on porous surfaces, coronavirus doesn’t live for more than about a day. So if you have a handful of masks and you can cycle them every few days, that’s probably a better scenario than picking up the same mask multiple times a day, you know, or day after day after day and then – until it wears out and throwing it out. Other studies that are unpublished yet – you put it out in the sun – it’s likely to die a little faster. So, you know, there are lots of things I think that you can do because we’re all in a position where we have to reuse masks, whether they’re made to be reusable or not, that put us in a position to have to make decisions that I wouldn’t normally suggest anyone make. We’re working on – and have been since the beginning – a variety of techniques to improve mask reuse both in the hospital and for the general public. And, hopefully, some of that will come to fruition soon, as well.”

So if you do not use a mask every day and can keep it out in direct sunlight between uses, that may make it ok, though the evidence is not yet definitive.


  1. Pierce R. Butler says

    … the idea is you’re done with your shift. You take it off. You throw it away.

    Meanwhile, every patient you deal with, except possibly the first, gets exposed to a surface exposed to every patient you’ve dealth with.

    Probably not that big of a risk factor, considering. But if (as many do) you wear the same gloves from room to room…

  2. says

    I actually read an article about people who fitted a uv nail lamp to sanitise masks.
    Otoh, you will still have all your snot in there.
    I’m lucky, I can sew and have made over a hundred masks so far. We also made more than 200 for our students so they’d all have one.
    There’s lots of them on Etsy places, consider getting a couple of washable masks. Soap effectively destroys the virus and some of them even look cool.

  3. says

    If they’re available, you can get disposable mask liners. They’re placed inside other (washable) masks and provide the same protection.

    In early April, Chen Shih-chung, head of Taiwan’s Central Epidemic Command Center (CECC), demonstrated how to disinfect surgical masks with steam and kill about 95% of the bacteria. It should be possible to do the same with a steam cooker (e.g. bamboo, and use for dim sum) over a pan of boiling water.

  4. captainjack says

    I only go out every 4/5 days for groceries or a doctor visit, so I have my disposable mask hanging outside from a window where it gets sun most of the morning. I have some left from when I had to wear one last year, so if I sneeze or cough in it, I throw it away. The same if I’m around someone who sneezes or coughs. I also wash my hands and face as soon as I come in, and check my temp and O2 saturation twice a day. I feel pretty safe, just really bored.

  5. says

    How do viruses react to microwaves?

    I don’t know, but the nose wire in many of the masks reacts quite strongly. Firefighters here had to make a PSA about it.

  6. John Morales says

    chigau, microwaves go down to wavelengths of around 1mm at best, and viruses are much, much smaller than that. Thermal effects on whatever substrate they occupy, however, should denature them pretty quickly.

  7. Ray de Silva says

    Disposable masks are made of plastic pseudo-fabric (polypropylene) and do not survive washing very well, but you could soak one in warm detergent and let it drip-dry -- once it’s dry it should be free of virus, bacteria and snot, all three. It won’t last forever, but you could get maybe 20 uses out of it. Keeping it out in the sun will, unfortunately, destroy it -- plastics degrade very fast under UV light. A bit like viruses. Or skin without sunblock.

  8. says

    I wear a bandana over the face mask I have.
    Unfortunately allergies have been a real nuisance here in Texas for the past few months.

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