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Comment by petilon | Hacker News Reader

Wouldn't just leaving the mask alone for say 72 hours decontaminate it? Viruses can't survive for that long, so should be safe to reuse the mask after 72 hours?

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The oven method only takes 30 minutes. So masks could be sanitized and turned around for reuse much more frequently than leaving the mask “out of commission” for several days would allow.

The report also found acceptable (if a bit lower) sterilization from applying steam from boiling water for just 10 minutes, which would improve turnaround rates even further.

I wonder if a clothing steamer would work.

Edit: In the vapor stream at ~4 cm from the outlet, I measure 63°C.

Maybe, but that might not be hot enough.

At 2-3 cm, it's well over 70°C.

What about other germs, esp from the doctors' own breath? Doctors in OR need sterile masks and hopefully they don't reuse in that setting. But outpatient clinics and testing sites, sure reuse is better than shutting them down due to shortage of respirators.

This is basically what I'm doing with a box of FFP3 masks I bought years ago and partly used. I only need to go out once or twice a week at most, so I can rotate through them and give each mask a good ~14 day rest.

IIRC, there were still traces of the virus on the diamond princess 15 days after it was cleared out. So it might be able to last longer.

The authors of that article specially mentioned their work on the princess would get badly reported - and it was. There was no live cornovirus found. Their were traces of RNA (ie, after the virus was killed some of its body parts lying around).

It's a half-life thing. If your equipment is sufficiently sensitive, you could find remaining virus for a long time. Especially if the conditions are right.

Right. People like to think of things like 'sick' and 'healthy' but maybe it's more subtle than that. Things aren't 'clean' or 'dirty' w COVID, but somewhere on a long spectrum.

Yup, it's continuous, not discrete.

My running joke with the "up to 3 days" figures people keep sharing is that you could get infected "up to 3 miles away" by someone sneezing if the winds/temperatures are just right and you're EXTREMELY unlucky.

There's also a distinct probability that your pencil will suddenly levitate an inch then drop back. I'm not kidding.

Next you’ll try to convince me that the moon can pull stuff from the earth towards it.

There's a small probability it'll stop doing that ;)

No, the 15 day thing was viral RNA, rather than live virus.

In the same way, you can find an identifiable skeleton, even after the person is dead.

The story I saw saying this was referring to traces of the virus's RNA, not active virus particles. More like footprints

No, SARS-CoV-2 is thought to have a half-life of about 72 hours on some surfaces but some virus particles can survive much longer.

(edit: that's not right, the half life is shorter with the virus still infectious on a surface for 72 hours or so)

https://www.youtube.com/watch?v=JNQUHc8wbRc

That video gives half lives of 5.6 hours for stainless steel and 6.8 hours for plastic, not 72 hours.

72 hours is the time it gives for the virus still being detectable/viable on those surfaces, which is different than the half life.

You're right, I misremembered the video. Still, 72 hours as the time when the last virus particle probably dies still seems a bit risky.

It would, but then you need multiple masks per person if each person uses theirs for 1 day. And even that can be a stretch: once they become moist, they're useless.

How moist? They will contain moisture from any use.

True, and they're not cracker dry to start. But if the pores get clogged with water (just like breathing on a cold window), you're hosed.

I was thinking the same. Or keeping it in very dry environment that desicate the virus?

Coronavirus survived for over a week on that empty cruise ship.

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