COVID-19 Emergency - Using UV Lamps to sanitize Face Masks overnight

[Houseman]

Hi all forum.
I’m Steve writing from Milan in the north of Italy where the Covid-19 emergency is by far the most significant here than in other parts of Italy.

As you may know (what happens in all Europe) we have a shortage in the supply of the non-reusable FFP3 face masks and the ones only available are used and reused for days even more than the datasheet suggests.
Here doctors are even forced to work using simple tissue dentist masks.
Having a wife that is a doctor I am wondering if using technology I could avoid in some ways the danger of reusing the same mask over and over maybe touching her face with a contaminated mask.
So I was thinking building her a 222-nm far-UVC light lamp in a box, where she can put the mask after use and being sanitized during the night.
I have read about Far UV lamps and the capability to kill germs and viruses:
Here an article on pubmed: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5807439/

I am asking if you think it is a good choice other than maybe change the internal carbon filter.

So I would like, if possible, start a thread in order to discuss and maybe be helpful also for other people and other countries since we have seen the pandemia is spreading worldwide and it will last for months.

Best regards and thanks.

Steve

[Mechatrommer]

https://www.hopkinsmedicine.org/health/conditions-and-diseases/coronavirus/2019-novel-coronavirus-myth-versus-fact
normal mask is likely not to protect you at all, you are more likely to get covid through your hand, skin or cloth contact. always wash your hand when you think you touched contaminated area, and your face too if someone sneeze or cough on your face, dont poke your eye, mouth nose with unwashed hand. be safe.

[SuzyC]

UV will kill bacteria but might also damage the mask fabric by ozone attack.

Why not a quick solution: dip/spray with > 64% C2H302 and then hair-dryer dried?

The Covid-19 Corona virus is encased in a lipid (a fatty cover) that is quickly dissolved by ethanol.

[mzzj]

I'd suggest overnight in 60 degrees oven, sauna or other improvised heat source.

CoV is similar to Ebola aka "enveloped virus" and should be reasonably easy to destroy.
https://www.cdc.gov/vhf/ebola/clinicians/cleaning/ebola-virus-survivability.html

60 degrees or even hotter 80C? 100C? shouldn't be a problem for the mask material itself.

Note that this is 100% unproven and non-professional advice but.. 

[Stray Electron]

  Steve,

   I've been wondering the same thing. Germicidal UV lamps operate at the same wavelength as EPROM erasers I believe and I have a pile of old EPROM erasers here.  The problem with UV is that it doesn't penetrate and it doesn't go around corners so it's only effective in direct line of sight.  I looking into using UV sterlization when I had a MRSA infection several years ago and it appeared that it would need several hours of direct exposure at close range in order to deal with most bacteria.  I have no idea regarding viruses.

   OTOH I'm also wondering if used masks could be washed, dried and reused.  A solution of Clorox and water would almost certainly kill the virus but might be to harsh on the mask.  I would think that a Hydrogen Peroxide or alcohol solution would be effective but won't damage the masks. Drying them in a warmed or hot, vacuum oven would be the fastest and would probably help kill any remaining bacteria or viruses.

   Ozone would probably also be effective in killed any viruses and UV lights usually generate a ton of ozone. Ozone would also penetrate the fabric of the masks. I have a large commercial HEPA air filter that has two germicidal UV lamps in it and it does generate some ozone.  Anytime that I get old musty books or other smelly items, I set them on top of it and let the air/ozone blow around them and it always kills the odor.  An old LASER printer that emits ozone will do the same thing.

[jfiresto]

Formaldehyde gas will also kill the coronavirus. You can use paraformaldehyde crystals as the generator. It is one method for sterilizing operating microscopes. In an air tight box – a must – the crystals should last for months.

[Bud]

The problem with UV is that it doesn't penetrate and it doesn't go around corners so it's only effective in direct line of sight.

People restoring vintage computers using retrobrighting technique reported that covering the inside of the container with aluminum foil produces even coverage of UV light because of reflection. Makes sense to me.

[Siwastaja]

I agree that heat should be easier to implement and more reliable in disinfecting the whole mask, not only the surface where the light hits. Try oven.

[duak]

I have been thinking about this too.  New masks would be better.  Used masks could become a infection source for anything nasty that grows on them.  I would expect that irradiating the masks with UV and then vacuuming them would not hurt.

UV lamps have been used in HVAC (Heating Ventilation Air Conditioning) systems for a number of years.  We have a central heat pump that I added a UV lamp to.  After over 10 years, the heat exchanger seems quite clean even though in the summer when it's cooling, it is covered with condensation.   The refrigerator, on the other hand sometimes develops a bit of mold in the condensate pan.

Good luck to all,

[Bud]

I'd suggest overnight in 60 degrees oven, sauna or other improvised heat source.

Speaking of which, I recently happen to modify the egg incubator (that I use for temperature drift testing) from 12V DC to AC power. Got a little cute MeanWell caged power supply which fit perfectly inside and replaced the DC power jack with a normal AC socket. Incidentally, the max temperature that can be set is 60C. Should things escalate, can be used for mask baking.

[Stray Electron]

   I wonder how much I can get for my old UV EPROM erasers/virus killers on E-bay?

[Stray Electron]

Formaldehyde gas will also kill the coronavirus. You can use paraformaldehyde crystals as the generator. It is one method for sterilizing operating microscopes. In an air tight box – a must – the crystals should last for months.

  Chlorine Dioxide works well too.  Good luck getting any if you aren't the Government! ClO2 is what they used to disinfect the entire US Congress building when they suspected it was infected with antrax. I expect that pure chlorine gas would also work but not many people want to work with that.

[StillTrying]

Would microwaving the masks for a few seconds or more work.

[Circlotron]

   I wonder how much I can get for my old UV EPROM erasers/virus killers on E-bay?

About 1 roll of toilet paper.

[Gyro]

Good old fashioned pressure cooker? - It's about as close to an autoclave as you're going to find at home.

[mzzj]

Good old fashioned pressure cooker? - It's about as close to an autoclave as you're going to find at home.

Works but probably 400% overkill and possibly damaging to the masks.

[thm_w]

Would microwaving the masks for a few seconds or more work.

Few seconds is not enough, a minute or two should be. But the problem is any sort of conductive element will cause havoc in the microwave, so you'd want to very careful. Think staples, reflective ink, etc. carbon filters might be an issue as well?

https://link.springer.com/article/10.1007/s11434-014-0171-3
https://www.tandfonline.com/doi/full/10.1080/0307945042000205874

[Gyro]

Good old fashioned pressure cooker? - It's about as close to an autoclave as you're going to find at home.

Works but probably 400% overkill and possibly damaging to the masks.

I'm not sure about overkill, a domestic pressure cooker it would probably be hard pressed to reach the required 130'C. Remember the mask would only be exposed to steam, not the boiling water. It would probably be a lot more gentle than dry uneven heat in a microwave.

[iMo]

Hopefully you all distinguish between a "face mask" and an "FFP3 respirator".

[NiHaoMike]

If it's sunny in your area, just leave the masks in a car parked outside. You'll be surprised how good of a solar collector a car is even on cooler days.

[ivaylo]

If it's sunny in your area, just leave the masks in a car parked outside. You'll be surprised how good of a solar collector a car is even on cooler days.

Car windshields filter UV though (unless you are talking about heat generation)...

[twospoons]

The problem with UV is shadowing. Heat or an alcohol soak would be better as they will penetrate the cloth, where UV will only disinfect the outside.

[rdl]

Intensity of any local source of UV light is going to fall off rapidly. I'm not sure you'll be able to to kill much of anything. Chemical or heat sterilization is probably best.

[mzzj]

Good old fashioned pressure cooker? - It's about as close to an autoclave as you're going to find at home.

Works but probably 400% overkill and possibly damaging to the masks.

I'm not sure about overkill, a domestic pressure cooker it would probably be hard pressed to reach the required 130'C. Remember the mask would only be exposed to steam, not the boiling water. It would probably be a lot more gentle than dry uneven heat in a microwave.

130 degrees C is required to make sure something like surgical equipment in hospital is 99.999999% free of ALL pathogens. We are now interested mostly killing some wimpy viruses, not bacterial spores or prions.
And even less than perfect result is better than nothing when you are in nearly war-like situation like Italy.
If 60 degrees is good enough for Ebola I see COVID no different. 

[not1xor1]

Hopefully you all distinguish between a "face mask" and an "FFP3 respirator".

yes all the replies are a pile of bullshit, some will just destroy the mask, other will make it toxic or not provide any sanitation

scientific literature (use proper search engine on the net to find that) proves that both ethanol and isopropanol destroy the capsid (the protein shell of the virus) in 30 seconds