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

[not1xor1]

Don't Laugh,  My supervisor just sent a partial box and our last unopen box of N95 to the local hospital.  At the emergent  request of a  surgeon alumni.  I'm in the Midwest USA.
That was our "Stash" for our critical personnel.

Steve

unfortunately there is nothing to laugh about... lots of people all dying all around the world... lots of medical staff too here
those personal protection devices are scarce all over the world

they are increasing production or opening new factories, unfortunately it will take weeks before everybody gets all the due protection devices

just stay at home, get out as little as possible, never get out even if you have few and mild cold symptoms, you might kill other people who is too weak to stand the virus

[taydin]

I have bought a 15 W UV-C lamp armature. Used it today to radiate shipment packages I have received today. According to my research, this type of UV-C causes DNA damage in virii and bacteria in a matter of seconds (I'm no expert, this is what I read, so take it with a grain of salt).

I basically hold the lamp towards the shipping package and because the light is behind the sheetmetal frame, I'm not exposed to the light. But here's what I have noticed: Within 30 seconds of turning the light on, there is a very slight smell in the air. I wondered what that is and researched. According to what I read, that is the smell of organic molecules breaking up and sulfur forming.

I went over the packages for a total of maybe a few minutes and wasn't exposed to the light directly at that time. But I know what it is to be exposed to UVC. When I first bought my TIG welder, I did welding practice for a few hours with a short sleeve shirt. I had severe sun burn on my arms and chest that lasted for a week.

This lamp is 15 W. There were also 30 W models available, but they were too long (90 cm), so I opted for the shorter one with less power.

[Zero999]

I have bought a 15 W UV-C lamp armature. Used it today to radiate shipment packages I have received today. According to my research, this type of UV-C causes DNA damage in virii and bacteria in a matter of seconds (I'm no expert, this is what I read, so take it with a grain of salt).

I basically hold the lamp towards the shipping package and because the light is behind the sheetmetal frame, I'm not exposed to the light. But here's what I have noticed: Within 30 seconds of turning the light on, there is a very slight smell in the air. I wondered what that is and researched. According to what I read, that is the smell of organic molecules breaking up and sulfur forming.

I went over the packages for a total of maybe a few minutes and wasn't exposed to the light directly at that time. But I know what it is to be exposed to UVC. When I first bought my TIG welder, I did welding practice for a few hours with a short sleeve shirt. I had severe sun burn on my arms and chest that lasted for a week.

This lamp is 15 W. There were also 30 W models available, but they were too long (90 cm), so I opted for the shorter one with less power.

The smell is due to ozone being produced when oxygen in the air is exposed to short UV wavelengths. Ozone is also an antiseptic so might be partly responsible for the sterilising effect of the lamp.

[Stray Electron]

  I came here to post a similar story. I dug out a box of old EPROM erasers that I had and took a look at them. They are marked as "shortwave UV 254 NM" (Nano Meters) so these are UV-C germicidal lamps.  The nice thing about these is that were apparently original built to observe fluorescence in mineral specimens and have a window in the case and a another case with a sliding drawer was bolted to it. Remove three screws and the second case with the EPROM drawer and half the shell of the first case lift off and reveal the lamp in it's holder. The Start and Off push button switches and the power cord are part of the case that remains so it's ready to put to work.

  The model on these is a Model DE-4 EPROM Eraser made by Ultra-Violet Products Inc of San Gabriel, Ca.  They're rated at .16 Amps at 115VAC so the tubes are probably 15 Watts or so.  These were a popular device back in the days when everyone used EPROMs.

    Here is a picture from E-bay of what one looks like https://www.ebay.com/itm/UVP-DE4-Eprom-Eraser-08H9RM/184214895527?hash=item2ae4103ba7:g:TOMAAOSwlNpecPCX

  What you smell is probably ozone and not a sulphur compound.

[taydin]

The smell is due to ozone being produced when oxygen in the air is exposed to short UV wavelengths. Ozone is also an antiseptic so might be partly responsible for the sterilising effect of the lamp.

According to this only UV light with a wavelength less than 200 nm will create ozone. My lamp is the standard 254 nm germicidal lamp.

[Zero999]

The smell is due to ozone being produced when oxygen in the air is exposed to short UV wavelengths. Ozone is also an antiseptic so might be partly responsible for the sterilising effect of the lamp.

According to this only UV light with a wavelength less than 200 nm will create ozone. My lamp is the standard 254 nm germicidal lamp.

Some do. According to the link you've just posted:

Most germicidal lamps, including those from UV Resources, are produced with doped quartz glass, which blocks the transmission of the 185nm ozone-producing wavelength. The doped quartz glass allows the 253.7nm radiation to pass through, but it blocks the 185nm wavelength from escaping. Therefore, germicidal lamps with doped glass CANNOT produce ozone.

Did you buy that lamp from UVR or was it from somewhere else? If it has a plain undoped quartz tube, then it will pass 185nm and produce ozone.

[taydin]

Most germicidal lamps, including those from UV Resources, are produced with doped quartz glass, which blocks the transmission of the 185nm ozone-producing wavelength. The doped quartz glass allows the 253.7nm radiation to pass through, but it blocks the 185nm wavelength from escaping. Therefore, germicidal lamps with doped glass CANNOT produce ozone.

Did you buy that lamp from UVR or was it from somewhere else? If it has a plain undoped quartz tube, then it will pass 185nm and produce ozone.

It's not from UVR. It's a chinese product, LIGHTEX. Nothing shows up when I search for it, so can't tell its construction.

[Zero999]

Most germicidal lamps, including those from UV Resources, are produced with doped quartz glass, which blocks the transmission of the 185nm ozone-producing wavelength. The doped quartz glass allows the 253.7nm radiation to pass through, but it blocks the 185nm wavelength from escaping. Therefore, germicidal lamps with doped glass CANNOT produce ozone.

Did you buy that lamp from UVR or was it from somewhere else? If it has a plain undoped quartz tube, then it will pass 185nm and produce ozone.

It's not from UVR. It's a chinese product, LIGHTEX. Nothing shows up when I search for it, so can't tell its construction.

Then it probably does produce ozone, hence the smell. The air would have to be very dirty and polluted for reactions with sulphur to occur, so much so, the air would already be very smelly to start with.

[james_s]

Even a lamp that does not produce much light of such short wavelength may still manage to create a bit of ozone, it can be smelled in extremely small concentrations. My hot tub has an ozone generator that uses a small UV tube which is made of quartz.

[taydin]

Then it probably does produce ozone, hence the smell. The air would have to be very dirty and polluted for reactions with sulphur to occur, so much so, the air would already be very smelly to start with.

That makes sense. The smell wasn't like a foul odor that is typical of sulphur anyway, so it is probably ozone.

In an FAQ that I read it says that the ozone will help killing germs that are not in the direct light path, so the ozone will actually complement the UVC light.

https://www.americanultraviolet.com/uv-germicidal-solutions/faq-germicidal.cfml

[Gyro]

You can always get a robot to do it... and the rest of the room (UV-C):

Coronavirus: Robots use light beams to zap hospital viruses

https://www.bbc.co.uk/news/business-51914722


I hope they use PIR sensors as well as a warning voice!

[najrao]

I am an old man stuck at home with only the woman I married 50 years ago. Neither of us is infected, so far as we know. I live in Bangalore, India, which has very low incidence of the virus infection just yet.
Hand sanitizers are in short supply. But I have a large hoard of isopropyl alcohol, 99+% strength which I use to clean pcb's and assemblies. Would it work as well as ethyl?
Let me have a quick reply please, thank you.

[Mechatrommer]

soap and water for 20 seconds is all it takes, probably much more effective, save you IPA for the worse later... its good if you have 1 ton xray machine that can kill anything but... why complicates things during this hard time? you can watch people dying while trying to build or wait for the order to complete/arrive.

[Gyro]

Hand sanitizers are in short supply. But I have a large hoard of isopropyl alcohol, 99+% strength which I use to clean pcb's and assemblies. Would it work as well as ethyl?
Let me have a quick reply please, thank you.

Isopropyl (IPA) is actually what they use in the medical environment and hand sanitizer. I think the normal concentration is 60-70%so you could let it down with water and maybe some liquid soap (to make it lather).

[fcb]

You can always get a robot to do it... and the rest of the room (UV-C):

Coronavirus: Robots use light beams to zap hospital viruses

https://www.bbc.co.uk/news/business-51914722


I hope they use PIR sensors as well as a warning voice!

I've seen one of these robots up-close and also under test.

Essentially they are just a bunch (Philips) UVC tubes.  99.8% of the electronics, software and smarts are about detecting when someone has walked into a room unwittingly, remote control and IoT wank.

They will ruin your eyes VERY quickly. I suspect they will also destroy alot of plastics used in the ward with more than occasional use.  Also, these are used AFTER you have already cleaned a room.

[Zero999]

You can always get a robot to do it... and the rest of the room (UV-C):

Coronavirus: Robots use light beams to zap hospital viruses

https://www.bbc.co.uk/news/business-51914722


I hope they use PIR sensors as well as a warning voice!

I've seen one of these robots up-close and also under test.

Essentially they are just a bunch (Philips) UVC tubes.  99.8% of the electronics, software and smarts are about detecting when someone has walked into a room unwittingly, remote control and IoT wank.

They will ruin your eyes VERY quickly. I suspect they will also destroy alot of plastics used in the ward with more than occasional use.  Also, these are used AFTER you have already cleaned a room.

It does seem expensive. It would be much cheaper to add some germicidal light fixtures (not expensive, just ordinary fluorescent tube fittings, with germicidal tubes fitted) to the room, with a PIR and interlocks to shut them off if anyone enters the room, when they're on.

[fcb]

There would be some benefit in moving the unit (robotic) - this would lower shading.  Probably more cost-effective to put several static units in.

[Buriedcode]

I am an old man stuck at home with only the woman I married 50 years ago. Neither of us is infected, so far as we know. I live in Bangalore, India, which has very low incidence of the virus infection just yet.
Hand sanitizers are in short supply. But I have a large hoard of isopropyl alcohol, 99+% strength which I use to clean pcb's and assemblies. Would it work as well as ethyl?
Let me have a quick reply please, thank you.

Washing hands with running soapy water is better than using hand sanitizers - because you're removing oils that help the virus stay on the skin.  Warm/hot water is preferable as this helps the soap grab the oils. But IPA will disinfect if its between 50 and 90% concentration, hence the 70% figure floating about on the web.  So thats handy for surfaces, the 70% concentration also slows down evaporation, because IPA and other alcohols don't "instantly" kill viruses, it takes time.

https://www.cdc.gov/infectioncontrol/guidelines/disinfection/disinfection-methods/chemical.html

[SiliconWizard]

Proper washing is better, but alcohol-based hand sanitizers are certainly better than nothing when/where you don't have instant access to anything else. Like with masks, it's again all about lowering the risks, not making them disappear entirely.

[Siwastaja]

I am an old man stuck at home with only the woman I married 50 years ago. Neither of us is infected, so far as we know. I live in Bangalore, India, which has very low incidence of the virus infection just yet.
Hand sanitizers are in short supply. But I have a large hoard of isopropyl alcohol, 99+% strength which I use to clean pcb's and assemblies. Would it work as well as ethyl?
Let me have a quick reply please, thank you.

It works, but you don't need it if you are self-quarantining. Just wash hands normally.

Alcohol-based products are a good addition to periods between being able to wash hands if you can't avoid going to public places.

[SiliconWizard]

The poor guy may still have to get out once in a while...

I think you can make your own mixture with water and IPA to get about 70% alcohol mix, then add some liquid soap (very little so it doesn't make foam) to the mixture to make it more gel-like. Glycerin would be better though if you have any available.

But quoting Wikipedia:

The World Health Organization has published a guide to producing large quantities of hand sanitizer from chemicals available in developing countries, where commercial hand sanitizer may not be available. According to this guide, to produce 10 liters of hand sanitizer, the following are mixed together, and topped up with distilled or cold boiled water to 10 liters:

    8333 ml of 96% ethanol, 417 ml of 3% hydrogen peroxide, and 145 ml of 98% glycerol, or:
    7515 ml of 99.8% isopropyl alcohol, 417 ml of 3% hydrogen peroxide, and 145 ml of 98% glycerol.[2]

[Martinn]

COVID-19 has a lipid coat which is easy to destroy with alcohol, so a > 62% (IIRC) alcohol solution would do, up to 99% ethanol or isopropyl alcohol.
However, killing bacteria requires a certain water content. Best stick to the 75% water content as in the WHO recipe.

https://en.wikipedia.org/wiki/Hand_sanitizer

[not1xor1]

I am an old man stuck at home with only the woman I married 50 years ago. Neither of us is infected, so far as we know. I live in Bangalore, India, which has very low incidence of the virus infection just yet.
Hand sanitizers are in short supply. But I have a large hoard of isopropyl alcohol, 99+% strength which I use to clean pcb's and assemblies. Would it work as well as ethyl?
Let me have a quick reply please, thank you.

it has been showed that isopropyl alcohol (ethanol too) does kill the viruses within 30 seconds, but somebody else suggested just wash you hands accurately with hot water and soap as that is as effective as alcohol and leave the alcohol for objects you can't clean with water

[jfiresto]

Doctors scramble for best practices on reusing medical masks during shortage: "Referring to a paper published in the journal Annals of Occupational Hygiene in 2009, among others, the researchers compared and contrasted ... different methods for sterilizing N95 masks, many of which were ineffective."

Two were, however: "70 C / 158 F heating in a kitchen-type of oven for 30 min, or hot water vapor from boiling water for 10 min...."

[profdc9]

Alcohol unfortunately can not be used to disinfect masks.  It destroys a charged layer in the N95 masks that attracts virus particles.  I wrote up a proposal for building a UV sterilizer for mask a couple days ago.  Anyone who is interested please E-mail me:

https://drive.google.com/open?id=1wF4yYgSE1n0Jqewb8JdwosTRhx0X89wF

This is a Google Drive link.

It is a difficult problem because UV can also potentially destroy the elastomers in the mask so that the mask no longer fits well on the wearer.   There is also cumulative damage to the filtration capability.  But it presently seems the most promising approach.   A paper in 2015 studied this:

W.G. Lindsley, S. B. Martin Jr., R. E. Thewlis, K. Sarkisian, J. O. Nwoko, K. R. Mead, and J. D. Noti,  “Effects of Ultraviolet Germicidal Irradiation (UVGI) on N95 Respirator Filtration Performance and Structural Integrity,” Journal of Occupational and Environmental Hygiene, v 12., pp. 509-517 (2015).
https://www.researchgate.net/publication/274090116_Effects_of_Ultraviolet_Germicidal_Irradiation_UVGI_on_N95_Respirator_Filtration_Performance_and_Structural_Integrity

There's a crowdsourced actively maintained document of resources at http://ppereuse.com/ .

Best,

Dan