Ultraviolet Virus Killer Masks

Ze sement hed iz hir! Zri jirz!

I think the LED's are still too expensive to make this workable....to reach the power level desired would require quite a few depending on exact wavelength and output...A small low pressure mercury lamp would probably be more practical...generally speaking the shorter the wavelength the faster the kill time, but clearly the penetration depth increases with wavelength, so a balance must be found that takes into account just how and where you want to kill viruses, and how fast you want this to occur to work as specified...Most of these I've seen are full face mask with a Hepa air filter and/or an activated charcoal filtering medium strapped to the waist and a hose feeding the mask with filtered air......It seems to me for the device to work properly you need to kill the viruses in mid flight...that means the velocity of the air must be taken into account and the Mw/cm³ delivered to the furthest reaches of the light chamber....

https://www.amazon.com/GermGuardian-LB1000-Replacement-Guardian-Sanitizers/dp/B001TLRSOA

https://www.amazon.com/Intermediate-TWDRTDD-Standard-Phenolic-Chandelier/dp/B07T669G3K/ref=sr_1_4?dchild=1&keywords=e17+light+bulb+socket&qid=1592352246&sr=8-4

https://www.amazon.com/UB1250-SLA-Battery-Volt-Hours/dp/B007PT81P0/ref=psdc_389574011_t4_B00B88CA4M

Air supplied full mask as pictured is the only way this would work. That goes for filters and/or UV kill approach. Never going to get a good seal with passive filter.

Sorry for the long delay in replying. I have been very busy with the prototype and trying to keep up with all the email.

I've only read about half the comments so far, but I'll try to reply to a few things now.

That 3M Versaflow is a nice looking air supply setup, but very expensive. Just the helmet is 400$!

The low pressure mercury UV tubes are no good for a personal pathogen killer mask. They put out 254nm UVC, which is excellent for killing all types of germs, but they also have a spike at 120nm, which creates ozone, which will kill you quicker than the virus will.

Plus, having a container of vaporized mercury with a direct path to your lungs is a bad idea.

Production of UVC LEDs is ramping up. When I first started working on this, everything was out of stock at Digikey except some from Rayvio, so I ordered them. Turned out the company had gone bankrupt from being sued for stealing the tech. So I had orphaned products without a spec sheet and burnt out 6 of them trying to figure out the right ohmage.

Learned later that you can't just put a resistor on UV LEDs because they draw more power the hotter they get! You have to use a current limiter circuit.

I'll read more posts now.

What about a simple disinfectant liquid filter

Followed by an identical filter, but with water instead of disinfectant (to stop smell getting through to the wearer).

The whole thing would need to be worn in a way which prevented spillage, and there would need to be sufficient "traps" to prevent spillage in the event of an accident.

What about a red hot grill followed by a water filter or other way to re-cool the air?

I wonder if a very high voltage grill (like those "tennis rackets" for killing flies) could be made to work?

I wonder if a very high voltage grill (like those "tennis rackets" for killing flies) could be made to work?

Maybe...

Airborne Virus Capture and Inactivation by an Electrostatic Particle Collector.

http://envbiotech.de/research/F-EST-virus-Eric-final.pdf

How long does the virus have to be in contact with the disinfectant to be effective...? ...also, as anybody who has smoked a water pipe can tell you, this would be too restrictive on the airflow without an air pump....

The electrostatic filter has the drawback as is the case with any accumulatory filtering device, is the need for maintenance...the filter has to be changed or cleaned religiously...

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7175919/

With this mask we are not concerned with dust so much, but with the much smaller virus and bacteria particles, so a targeted approach is best...and killing or disabling the virus or bacteria is preferential to just trapping it...The simpler the better, and low maintenance is key...A properly sized uvc light can disable the viruses and bacteria without the need for actual trapping with a filter....activated charcoal canisters can last for a long time without clogging up...This minimizes the accumulation of debris being trapped leading to a low maintenance solution..

Maybe you need a combination of electrostatic precipitation to immobilize the virus and UVC to kill it. Once nailed down, the exposure could be much longer and more concentrated than if the virus were just passing through in the airstream.

Just a thought...

An air chamber, an expanded vessel, which contained the light, would slow the velocity of the air....

https://www.amazon.com/s?k=activated+charcoal+canister+filter&crid=2JCEH4IX3X9HU&sprefix=activated+charcoal+canister%2Caps%2C193&ref=nb_sb_ss_i_1_27

That's the idea.

I've made it so the germs can't just pass straight thru the chamber. They will swirl around alot, and have to pass thru a particularly concentrated zone before leaving. Then there's another filter set.

What about a Cobalt 60 based killer mask? The approximately 1.2 Mev (0.001 nM wavelength) will certainly kill this pesky virus. With a five year half life these masks should be effective for a good long time and without the need for batteries.

The answer is far-uvc at the 222nm wavelength which is harmless to eyes and won't penetrate skin (as opposed to the common 254nm wavelength). I'm surprised that there hasn't been a massive push to ramp up production (it's fairly new) as it will kill a virus in 2sec. A few lamps in every room would disinfect the room safely and constantly. Hopefully it's happening but I just haven't heard about it.

The excimer 222nm lamps are still a new technology, there is a lot details and testing to be worked out...If they need to be regulated, certified, and by whom, FDA, USDA or OSHA...What power level at what distance for how long achieves what results? The market is being flooded by UVA lights claiming to be UVC, so there is a lot of fraud, questionable claims of efficacy, and lack of standards that need to be addressed by the industry...

I think they need to have classifications for different applications...A lamp that is 100% effective for 2 seconds at 2 inches of exposure, and a lamp that is 99% effective in 2 seconds at 4 feet, needs to be certified and guaranteed to work if this is for sanitation of viruses and bacteria....There needs to be enforcement and legal recourse for claims made by manufacturers and distributors...This is the only way that pricing can stabilize is with valid results for dollar spent...any device sold for sanitation should be designed for a certain class of use and effectiveness and must meet those standards or face legal action....

A lot of these portable wands being sold for sanitation that claim results don't mention that due to the low power output they need to be under 1 inch away for several minutes, they are essentially useless...So an effective range and time of exposure needs to be listed with these devices...

I've read conflicting articles about UVC safety. Something similar to what you wrote turned out to be promo copy from a manufacturer.

Another said that the further you go under about 240nm, the more ozone it generates.

Another stated that the 'best' frequency of 254nm was only because that's the frequency produced by the mercury tubes and that the ideal frequency has yet to be determined.

The LEDs can be tuned to a very specific frequency when they are made. I chose 280nm to be safely above the ozone generation level.

The SARS-CoV -2 virus is basically easy to kill use a bacterial soap, that is wash your hands with soap and water. There are products out there that also kill the virus when it is airborne, the company I am working with uses what they refer to as NPBI, Needle Point Bipolar Ionization. Here the risk of excessive Ozone exposure is eliminated. I am also looking at a product called airtamer to help keep an ionized layer of air around my face and will evaluate it soon. The UV-C is a way but not as effective in a shield like setting When you use ultra-violets think of it in terms of radiation that is gamma rays the most penetrating equate to(UV-A) next Beta (UV-B) and then the least penetrating Alpha (UV-C) unfortunately the radiation must be applied to the direct surface area you are wishing to decontaminate, hence no protection zone where as in air ionization the ions fill a zone around the source and provide a virtual kill-like shield against the virus. You can learn more about how the virus is killed with a little research on your own. GPS has testing that shows it kills 99.+ percent of the virus in 30 minutes in an area. the test results are available on their site.

Far uvc at 222nm has been tested and shown to kill aerosol born viruses in an air stream in a fraction of a second...Water purification uvc systems are not new and have been tested extensively to eliminate bacteria in a stream of water...so saying uvc doesn't kill bacteria and viruses that are airborne, I don't think is accurate...I might also argue that grid ionization does produce ozone and would need to be filtered through activated charcoal before breathing...Having worked with filters for many years I can tell you electrostatic filters don't work all that well with a single pass grid...but I will add that I have never seen any testing on any electrostatic powered breathing apparatus...so if you have any studies that have been done please link to them....

Where do you get these conclusions? The Wikipedia page on Ultraviolet Germicidal Irradiation in the subsection on uses states the following:

Air disinfection[edit]

UVGI can be used to disinfect air with prolonged exposure. In the 1930s and 40s, an experiment in public schools in Philadelphia showed that upper-room ultraviolet fixtures could significantly reduce the transmission of measles among students. In 2020, UVGI is again being researched as a possible countermeasure against the COVID-19 pandemic.[18]

Disinfection is a function of UV intensity and time. For this reason, it is not as effective on moving air, or when the lamp is perpendicular to the flow, as exposure times are dramatically reduced. Air purification UVGI systems can be free-standing units with shielded UV lamps that use a fan to force air past the UV light. Other systems are installed in forced air systems so that the circulation for the premises moves microorganisms past the lamps. Key to this form of sterilization is placement of the UV lamps and a good filtration system to remove the dead microorganisms.[19] For example, forced air systems by design impede line-of-sight, thus creating areas of the environment that will be shaded from the UV light. However, a UV lamp placed at the coils and drain pans of cooling systems will keep microorganisms from forming in these naturally damp places.

As this section points out UVGI certainly can and has been used in HVAC systems where the airflow rate can be regulated along with the intensity of fixed UV light so a sufficient dose can sterilize the air but this is far from a practical approach for a portable system utilized in a mask.

...."this is far from a practical approach for a portable system utilized in a mask."...

How so?

"How so?" Now that is a bold rebuke for somebody that provided only a link for locating activated charcoal.

As I stated earlier, the use of UV light in HVAC is already happening. Scaling this approach to sterilizing the 72 to 120 liters per minute of tidal breathing air just before inhalation is not practical. This will require either an extremely bright UV source (or Cobalt 60) or a much larger volume of space than the volume of a mask.

I guess you didn't see my links in #3 ...to this bulb

Voltage: 11V DC; Current: 0.3A; Base: E17; Intensity: 450uW/cm2 @ 30mm; Wavelength: 254nm

Why don't you think this is sufficient for an air chamber similar to that above...?

That bulb will likely help to sterilize the air in a room and certainly many of the exposed surfaces of said room but it will not have enough time to sterilize the air entering the lungs through a mask.

Now having one or a couple of these bulbs to sanitize the filtering surfaces of a reusable mask between uses sounds like a good idea.

..."So if your UVC lamp has an irradiance of 5 mW/cm² at a specified distance from an object, then holding the lamp at that distance from the object for 8 seconds will deliver a dose of 40 mJ/cm², because 5 mW/cm² multiplied by 8 seconds = 40 mWs/cm² or 40 mJ/cm².

A dose of 40 mJ/ cm² is generally considered sufficient to disinfect (99.9% reduction in infectivity) a wide range of bacteria and viruses, including certain coronaviruses that infect animals (Malayeri, IUVA News 2016)."....

https://www.consumerlab.com/answers/does-uv-light-kill-coronavirus/uv-light-covid/

https://www.researchsquare.com/article/rs-25728/v1

...."I understand one needs 1/100 of a watt-second per square cm for water purification using 254 nm UV. What is the dosage for air?

Most regulatory bodies now specify a fluence or UV dose of 40 mJ/cm² (note that 1 mWs = 1 mJ) to assure at least 4 logs inactivation of any pathogenic microorganisms. Since the fluence or UV dose applied is independent of the medium, this requirement would also apply to air. However, I am not aware of any regulations as yet regarding UV air treatment."...

https://iuva.org/uv-faqs

=89 seconds of exposure for 99.99% kill....

..."The average minute ventilation is 6 litres per minute."...

= 9 liter tank...or two bulbs and a 4.5 liter tank...

...."UV-C light has been used as a disinfectant against viruses and bacteria for more than 40 years. Now, researchers at Boston University and Signify (formerly Phillips) have confirmed that it also effectively eradicates the SARS-CoV-2 virus.

Specifically, a 5mJ/cm2 dose of UV-C light eradicated 99% of the SARS-CoV-2 virus in 6 seconds, according to testing by Anthony Griffiths, Ph.D., associate professor of microbiology, in Boston University’s National Emerging Infectious Diseases Laboratories (NEIDL). Based on the data, he and his team determined that a 22mJ/cm2 dose of UV-C light will result in a reduction of 99.9999% of the virus in 25 seconds. That translates, at a basic level, to needing a 13W UV-C light bulb to kill viruses in a 10 x 16 foot (15 square meter) room, for an undetermined period of time."...

https://www.biospace.com/article/uv-c-light-kills-sars-cov-2-triggering-novel-lighting-options-for-public-spaces/

mJ or mili-joule is one thousandth of a Joule or a measurement of mW one one thousandths of a watt for one second....so 5 mW/cm² for six seconds would be a dose of 30 mW/cm² ...

So to get to a 5mJ/cm² dose we would need 11 of the 3 watt bulbs or 6 of the double 5 watt bulbs for a 1 second kill time...or one 30 watt bulb....or maybe 1 or 2 of these

https://www.intl-lighttech.com/products/e275-60-strip?gclid=CjwKCAjw57b3BRBlEiwA1ImytlPKWUhZ-sJn4R3bRqymiWB7F_Fs9Spq-snjH2Cxw3t1agAbMO6aSBoCdsAQAvD_BwE

A demonstration of "back of the envelope" engineering mathematics seems to be in order.

From the Wikipedia page on UVGI on inactivation of microorganisms:

Dosages for a 90% kill of most bacteria and viruses range from 2,000 to 8,000 μW·s/cm²

So the volume within 30 mm of one bulb will not be sterilized to 90% until at least 5 seconds of time has elapsed. A 30 mm diameter sphere is only 0.014 liters in volume. (V=4/3 * pi *r^2) The tidal breathing of the lungs were earlier identified as about 1.2~2 liters a second. One of these itty bitty bulbs will not sterilize 1 liter of air in a minute, let alone every second.

Ineffective personal protective equipment can easily become more dangerous than no personal protective equipment.

Really you're breathing over 1.2 liter's of air per second??? I don't think you could ....I think that wiki article is a little dated...

Huh? Not precise, but I just exhaled about one second worth of air into an empty plastic bag, which filled it to about two quarts.

Yes but you are not a good example, everybody knows you are full of hot air....

An average dive tank holds about 2200 liters of air when charged...it lasts about an hour....60 min times 60 sec = 3600 seconds = .6 liters per second so 9 liters would be good for 15 seconds....

2 of these bulbs should be enough...

Probably easier to just do the whole room....

Go Big or Go Home...

https://ultraviolet.com/high-intensity-germicidal-ultraviolet-lamps-2/

That is precisely my point. It is easier to do a whole room than the air about to enter a person's lungs.

OK what about vortex cleaning, how fast would you need to spin the air to extract the virus particles? ...centrifugal forces with a sticky catch surface and biological death trap...

Continuous circulation of air from an air chamber would cycle the air numerous times, the receptor chamber would be a very sticky medium that would trap the viruses and a friendly strain of bacteria would eat the trapped viruses, leading to low maintenance solution....everybody would walk around sounding like vacuum cleaners...haha

The tidal flow (each direction) is at least twice the average cycle flow, so the tank statistic is irrelevant.

I purchased 2 cheap rechargeable battery powered UV sterilizers. They both use mercury lamps that generate ozone as part of their germ killing performance.

As cheap as they were, they both had instructions (a rarity these days, especially from Chinese companies) and warned against being in the room when the units are in operation.

One starts 10 seconds after you hit start then runs for 7 minutes. The other runs for 20 minutes after the delay. They also say to wait at least 30 minutes before reentering the room.

It doesn't make any difference how ozone is generated. It may smell fresh, but it will corrode your air passages and lungs. It will also go after all sorts of plastics, paint, cotton, wood.

That's why you use an activated charcoal canister after the light chamber, to neutralize the small amount of ozone produced, but still reap the benefit of its germicidal effect...at least that was the idea...and further I don't think ozone is produced above about 190nm...The low pressure mercury vapor lights have 2 peaks of irradiance, 185nm and 254nm, the lower wavelength can be blocked with a filter coating on the bulb, that's why you see them with and without ozone listed...but this varies according to amount of mercury and pressure, so you need to see the spectrum from the specific bulb you are using to make accurate calculations...

https://www.aquafineuv.com/uv-lamp-technologies

..."They can also be manufacturing from materials such as fused quartz (ozone producing, 185 & 254 nm), ozone free quartz (254 nm) or synthetic quartz (suprasil,185 & 254 nm). They can also be ozone free with our various phosphor coatings if targeting a specific wavelength."...

http://www.jelight.com/low-pressure-mercury-lamps/

Still, better to not have the chance that the tube can break or have a manufacturing fault and you inhale mercury.

Then there's the bulk. LEDs are tiny - 3.5mm square.

Any mercury vapor would be captured with the activated charcoal canister....without that you would have to go with LED's, the problem is the price....those pictured are 275nm at 20mW/cm² that's all 6 combined I think, and around $65, you would need at least 2 I think, that's without the power supply and fairly large battery pack....too expensive

We've come far but moved little.

I can understand how it is frightening to some that we have not advanced beyond this point in combating such diseases.

The thing of it is, when every one does it, it really does work.

Basically the same thing we are talking about here. The basic idea was pass the air through some sort of disinfection material.

The Beak contained different things depending on the area. Most often is was a combination of herbs and such with know antiseptic properties while others had vinegar soaked material in them. effectiveness of that is debatable given how the plague was transmitted but the cleanable/ disposable full body covering was and is still very effective.

Like I said, we like to think we've come far but we have not really. We are relying on the same things because its all we have. We like to try and comfort ourselves with technology, but the reality is we still don't have any effective means of responding to this sort of situation, so almost 1000 years later we still rely on masks, isolation, "waiting for the danger to pass", and unfortunately quackery.

Pass the laudanum please!

I thought the plague was vectored via insect (flea) bites. Packing the airway with enough material to block the critters was probably effective to prevent the plague. A secondary bacterial or viral infection would require some antiseptic barrier for good protection.

We should give the makers and wearers of these hoods full credit for finding a working solution without understanding the mechanism. Antony Van Leeuwenhoek did live in the 17th century but it took time for the idea that something so small could be the root of a disease.

You are correct Red. The fun fact about the plague is it was not the only problem of the day. Tuberculosis was also rampant and the two often occurred concurrently leading to the idea that it might have been airborne. Or in the case of the Catholics of the day, caused by evil spirits and witchcraft.

How does that work? Packing the airway keeps fleas from biting the inside of the lungs?

I like those masks!

Fashion will be very important for the success of any products derived from this project.

The deranged scary weirdo demographic is likely to grow to a major market segment as America descends into barbarism.

We have UV lights everywhere as one might expect in a plant the produces bacteria.

What we have learned through injury and lawsuit is humans and UV lights should not be in proximity. Period.

When you think about it in basic terms it makes sense. Humans are biological organisms and UV lights kill biological organisms.

The Sun produces UV rays, all it takes is a little sunblock....or glass...

All the good ideas put together...well not all of them....ok some of them..

https://www.yankodesign.com/2020/07/18/worlds-first-antiviral-face-mask-with-active-uv-c-sterilizing-makes-it-easy-to-breathe-99-clean-air/

https://www.kickstarter.com/projects/umsystems/uvmask-inactivate-9999-of-all-pathogens-and-air-pollutants?utm_source=kickbooster-direct&utm_medium=kickbooster&utm_content=link&utm_campaign=032652fa

Looks like a good product.

My only question is the intake velocity.

It has a very small cross section in the UV vortex, so the air will go thru it very fast. It could possibly be too fast to be effective. Also, I am very skeptical of the claim that its "10x faster than you can breath".

Maybe he means the air is moving 10x faster than your normal inhale speed? That would make sense, but it's bad, not good.

Odd that it's on Kickstarter. I thought they specificly prohibited anything making health claims.

Here's a bogus UV mask.

https://www.indiegogo.com/projects/leaf-mask-world-s-first-fda-uv-c-n99-clear-mask/x/24116430#/

No surprise that skammers are harvesting money from gullibullz with flashy ad campaigns. Notice the standard marketing tools - Smiling families. Happy pretty people being athletic. Scowling super models. Pretty young scientist doing science. Strategic use of color (violet, blue, pink). Scientific-sounding hype and charts.