The concept is good [1], but the hardware is crappy.
There's a lot of fake junk out there. The fake junk comes in two forms - UV lights that emit in dangerous parts of the spectrum, and UV lights so weak as to be at "homeopathic levels".
Lamps that emit around 222nm are significantly more expensive than the wrong lamps.
For now, yes. But with more research behind the efficacy, a better understanding of the Ozone issue, and ultimately more interest/investment from businesses assuming good results, the products should improve.
By the looks of it the LED's are in plastic cases. The actual UV LED's that can be used fro sterilization come in metal cases with glass windows. And they cost multiple dollars per LED. Basically the LED's on that product are the wrong frequency to be effective. 300-400nm instead of 250nm.
UV light is also pretty bad for humans, is it not? Sunburn, skin-cancer, and all that. I seem to recall a recent mistake where some UV disinfectant lights were used at an event, resulting in sunburns and eye problems for many attendees.
The article does address this and is talking about a variety of techniques for UV light that has less exposure to people and doesn't result in immediate harm. But presumably this would still be more exposure than sunlight (otherwise, the sun would be killing all these bacteria/viruses anyway), and I'm not aware of any studies assessing the risk of long-term exposure to those levels of UV. If you want to install these systems in buildings, you'd need to assess the risk of literally years of continuous exposure to deem it safe. The couple of weeks on an oil rig proposed in the article wouldn't cut it, from a safety point of view.
As described in the article, far UV does not appear to be directly dangerous to humans at all. However it does produce Ozone, which can be dangerous - the question is how significant that would be in real, world settings, which is being studied.
Study it all they want, I really don't want to be under artificial UV in an office setting for 8-10 hours a day. Especially since the germs will eventually become immune to it under such persistent steady evolutionary stress. We have enough cancer contributing technologies in our life already without adding more ozone and UV.
Right, but just because it doesn't appear to be dangerous doesn't mean it won't be in the long term. Unless there've been studies already done on the effects of long term exposure, I'm inclined to be cautious. Things like this can have long term effects that aren't immediately apparent.
Having posted this article, I must say it's disappointing the number of people who appear to be expressing knee-jerk reactions to the headline alone. I guess anything related to pathogens and public health are a hot-button topic these days and perhaps that's why?
I just found it interesting and exciting to read an overview of where this research is going. The ozone issue is unfortunate, as I was originally very excited to read the results showing no direct impact on skin or eyes, but then that aspect does put a bit of a damper on it. But still, perhaps that can be addressed somehow, or with further study might turn out not to be a major issue, and regardless it seems there will at least be niche applications. And perhaps widespread ones. Anyway, it would be nice if we could engage on this topic with the same spirit of open mindedness and intellectual curiousity as we're accustomed to here.
So because of some turn of events, I was enrolled in a privately owned school in Shenzhen, China, around the year of 2010, for a year.
In the primary school, all classes have UV lights to kill germs. So upon leaving the class, the last student would turn off the (normal) lights and turn on the UV lamps. In the morning they would ofc turn off the UV lamps and turn on the normal lighting.
I'm not gonna talk about efficacies or whether it causes harm, it might as well be placebos, but from what I know, it's kind of common to have.
That's very interesting, I've never heard of that.
Of course that couldn't do really anything about typical airbourne diseases, but it should help "clean" surfaces somewhat. I wonder if anyone has studied the effect of that.
I just ordered a set to check them out for myself, although I don't know how I could possibly measure their efficacy in killing pathogens or their risk to humans.
Pretty sure these are based on (relatively) inexpensive KrCl excimer lamps, which are available on Aliexpress and such. The big question in my mind is whether or not it's a big enough dose to actually sterilize a room.
On the site "Care222modules use an excimer lamp in combination with a special optical band pass filter that blocks the ultraviolet wavelengths that could have a harmful effect on people. Care222 is the only Far UV-C product in the world with this key technology." why is this key technology so difficult? And why is the product so expensive?
Looking at uvb there use to be several afordable manufacturers with good test data but they all closed shop. What is left either doesnt work or is scarry expensive.
The lamps are cheap the coating is hard to develop. Im not sure but it seems if you want to produce it you have to redo the rnd to figure out how.
That is a thing that's done. The idea here though is that UV lights are a much cheaper retrofit than HVAC systems, so they could be a huge improvement in places that don't have good HVAC.
I wonder if it would be possible to have a small, battery powered device that could gently blow sterile air back at you for a couple of hours. Or maybe something you could wear around your neck?
This is already a thing, and many companies and government agencies have been spending time and money on it for years. It is, indeed, a viable approach.
> Ultraviolet light can kill almost all the viruses in a room. Why isn’t it everywhere?
Simple--cost.
Specifically, UV lamps require maintenance and can be dangerous to those doing the maintenance since the flux is large and damaging to humans.
UV LEDs change this calculus slightly as they can last a lot longer, but they are still dangerous to maintenance people.
The interesting question is whether the Far UVC (222nm) LEDs can be made useful while not being harmful to people. That would change the calculus from "do a detailed cost/benefit analysis" to "what the hell--just throw it in".
I'd love to see the 222nm LEDs finding their way into sterilization products, but unfortunately that's still a long ways off. They're really only useful for sensing applications at this point (although that's still a very important use case).
> I suspect that subjecting people indoors to an amount of UV radiation comparable with a day outside might be OK
And I suspect this is very incorrect. UV is beneficial at low quantities, but has serious negative impacts on human health at high quantities.[1] Your mention of using it in common areas (where individuals would only be for a few minutes a day) seems much more reasonable.
The far UV spectrum being talked about here is not the same as conventional UVC germicidal lamps, nor the same as UVA/B from the sun. UV is only dangerous because at UVC wavelengths it penetrates cell nucleii and damages DNA.
The interesting thing about far UV though is that while it will still damage DNA, it can't penetrate regular cells - it's blocked by the cell membrane/proteins. But viral particles don't have a cell membrane or a nucleus, so they have no protection against it.
Basically, far UV can't damage cells, but can damage viruses.
Personally I feel the use of the term "far uv" is very misleading because the 220 nm wavelength is within UVC, and not too far away from 254 nm germicidal UVC.
It is always helpful to consult a chart:
So, from a public health/public education standpoint, I find it troubling that scientific research, which the article points out, is limited in this area. For decades, general advice has been that all UVC is dangerous to all life. We don't know below which wavelength does UVC no longer become harmful to animal (human) cells. Nor do we know if 220 nm wavelength light damage/weaken other materials. I'm not a chemist/engineer so I don't know if theoretical calculations can be made or if a massive scientific effort needs to be done to verify the impact of 220 nm UV light on lots of materials/life.
If there is an animal/human cell safety region, perhaps a rebranding or subdivision of UVC into a "UV-D" is better than calling this "far uv". This has the added benefit of the "D" meaning "Death to germs/viruses".
Edit: maybe I am a bit alarmist, some comments did share additional information about products offering this technology... I still hold that the branding/messaging is a problem by lumping it all together
As I understand it, the point of 222nm is NOT to sterilize organic tissue directly.
The point of 222nm is to able to use it for sterilization in things like air return ducts, industrial cleaning equipment, etc.
Since 222nm is relatively "safe", you don't have to worry some idiot opening up a system, giving himself a gigantic flux of UV in the face, and winding up in the ER for cornea burns.
Consequently, your maintenance people don't need special equipment or extra training.
This is the point of mechanical/electrical interlocks to prevent exposure to energized UVC. This is why I find the attempt to make 'far uv' safe in the public conscious even more dangerous.
> The far UV spectrum being talked about here is not the same as conventional UVC germicidal lamps, nor the same as UVA/B from the sun.
I was responding to someone suggesting outside-levels of UV exposure. If we're talking about a different wavelength, I am even more doubtful of the safety.
I sterilize my N95/KF94 masks with UV light for reuse.
If anyone wants to follow suit, beware fake UV bulbs. Test your product / bulb with a banana.
Put masking tape on the banana, then expose the banana to the light for a few hours. If the band develops a suntan except for under the tape, you've got a good bulb. It should kill any bacteria and certainly any viruses on your mask.
But still throw out your masks when the fit gets bad; a mask is useless if the COVID is slipping in through the sides.
>If the band develops a suntan except for under the tape, you've got a good bulb.
Beware, heat from the lamp can also cause a "suntan". That's why checking under the tape is a mandatory step. If even under the tape is tanned, it is caused by heat and the test is invalid.
the answer is no, I was reading the linked documents and:
1. yes UVC of that frequency kill virus but they don't provide results about human safety, the say "potentially":
"Germicidal ultraviolet light, typically at 254 nm, is effective in this context but, used directly, can be a health hazard to skin and eyes. By contrast, far-UVC light (207–222 nm) efficiently kills pathogens potentially without harm to exposed human tissues."
2. A study on rats is linked, but it doesn't prove the human safety;
3. The author of the study is economically interested to exploit commercially that sterilisation technique. further reason to wait for serious verifications:
“The authors declare the following pending patent: Patent Title: “Apparatus, method and system for selectively affecting and/or killing a virus”. Applicant: The Trustees of Columbia University in the City of New York. Inventors: Gerhard Randers-Pehrson, David Jonathan Brenner, Alan Bigelow. Application #: US20180169279A1. Aspect of manuscript covered in patent application: Use of filtered 222 nm UV light to kill viruses URL: https://patents.google.com/patent/US20180169279A1/en?oq=2020...
“D.J.B has a granted patent entitled ‘Apparatus, method and system for selectively affecting and/or killing a virus’ (US10780189B2), that relates to the use of filtered 222 nm UV light to inactivate viruses. In addition, D.J.B has an ongoing non-financial collaboration with Eden Park Illumination, and the authors’ institution, Columbia University, has licensed aspects of UV light technology to USHIO Inc.”
4. Invisible light is dangerous, you can injury your eyes, without realizing it and, devices from unreliable resellers could hide more serious risks.
P.s.
Reading patent details: "to prevent the at least one radiation from having any wavelength that is outside of the range can be provided or which can be substantially harmful to cells of the body". What means "substantially harmful" radiation ? That is harmful but not so much ? A little bit harmful, maybe? Tell me if I'm wrong, because, for me, if something can't damage anything is "harmless", not "probably harmless" or "not substantially harmful". That is the language of the lawyers or the sellers. They simply don't know yet.
P.S.2 What about photochemical effects ? You put this inside a home and UVC start to discolor everything around. Besides piss off customers, could create serious legal problems to the seller. You know, damage to expensive furniture, paintings, etc.
I looked it up and what happens is that over long time periods in sunlight, CFCs lose a chlorine radical, and that chlorine radical lives for a long time and catalyzes ozone to turn into normal oxygen molecules.
So it would only even possibly be effective if you have so much CFCs and so much light that it builds up a bunch of chlorine, enough to get rid of all of the ozone. My guess is that even if those reactions occur in the context of a home (which seems like a big if) they'd be so slow and require so much chlorine and CFCs around that you'd be dead before you could celebrate.
Not to mention you'd have to be releasing CFCs in ~every building constantly, which would destroy the ozone layer orders of magnitude worse than we did decades ago.
Ha, I love it. I imagine spraying those into the rooms would be even worse though. And if you do it in an HVAC system you might as well just do the UV there too, in which case the ozone would break down before it was an issue. (And in fact could even be beneficial killing pathogens itself.)
The main advantage of the near UV lights is that they can be inexpensively placed in locations that don't have good HVAC systems.
it's not the cfcs themselves but their chlorine breakdown product (in uv light). certainly there are disadvantages to adding free halogens such as fluorine and chlorine to your air (chlorine used to be a major chemical warfare agent, and fluorine wasn't only because there's no practical way to carry it around, it being the closest real equivalent to the legendary alkahest), but unlike cfcs halogens are not persistent in the environment, and it's not unimaginable that the required levels of halogens would be less harmful than the ozone they removed
platinum, though, can catalyze the same decomposition that chlorine does, so
i suspect that a much more reasonable approach is to use platinum catalytic converters, so the catalyst remains contained with a box instead of going into your lungs
Having significant air movement (like an actual felt breeze) is really all we need, so I'd consider this an accesory. And this would be super nice anyway in places like elevators and restrooms which are rarely ventilated to a good level.
Good circulation definitely helps, but it's not a panacea, unless very well designed. I recall a case from the early covid days where contact tracing showed a bunch of people catching it in a restaurant; it turned out what they had in common is that they were all downwind of the carrier from the relevant HVAC vent.
Some restaurants retrofitted fancy setups with individual vents or even partial center enclosures for each table, but obviously that gets quite expensive, especially compared to a UV bulb.
I do generally agree with you though that proper circulation and filtration can be very beneficial in limiting spread of pathogens.
If this will kill all bacteria and viruses, it would certainly also destroy the beneficial bacteria that forms our microbiome and that could have negative health effects in the long run. Has any research been done to check on this?
I could be mistaken but I think your micro biome mostly doesn’t depend on external input in the form of microbes.
Rather, you have microbes, and these depend on external input in the form of nutrients.
There are exceptions such as yogurt and sauerkraut etc. but those are kept in a fridge and would not be exposed to far uvc most of the time. It would be interesting to know how they are affected during meals.
Skin micro biome might be more affected. I could not find much information on this point.
The problem is that when people start installing these but accidently brought fakes/cheap, you'd get sun burns and eye burns and won't know from where.
No, you can't expose people to UV light all day, they will get sunburns, skin cancer and lose their site.
Then there is the issue of whether UV light can kill airborne viruses soon enough after being exhaled so they are dead by the time someone else breathes them in.
Because sterilizing lamp use UVC ( more than 250 nm ) that hare ionising radiation, they cause cancer in long / medium term and burn your eyes immediately. Recently I read about a party where "diversely intelligent people" used UVC sterilising lamps as light effect, with this result:
This is not a scientific journal, anyway I read the article and it is mix of unrelated sources:
- a test on certain UVC wavelength radiation on MOUSES*
- a study of UVC filters for eye safety
That to conclude that we should use UVC as anti-virus measure. GREAT !!!
A critic to HN in general, not related to this specific post: lately I see a proliferation of posts related to pseudo scientific article, should be more simple to flag them, especially when, as in this case, could give really bad ideas to people easily convertible in series injuries.
What happen if some parent put UVC lamps in children rooms to save them from infection ?
Maybe matter of medicine and public health should be taken from reliable sources, not from VOX. Just my opinion.I'm waiting for someone suggest game rays next times, sure they are more effective for sterilisation.
P.S.
The more laughable part is when he use as reference an article from the '30s, when people could purchase objects made from really dangerous isotopes because there wasn't little or no clue about the effects of radiations in general.
In the '50s, some shop in USA had a x-ray machine to check if shoes was of the right dimensions.
254nm UV is harmful to human eyes and skin, and shouldn't be directly exposed to people. 222nm UV is safe for humans, since the wavelength can't penetrate the outermost layer of skin/cornea.
This is discussed at length in the article, so I'm surprised to see this top of the comment page. I suppose it flatters HN readers' view of themselves as smarter than journalists.
> “Upper room” UV, the primary form of UV disease control tested to date, is a kind of compromise. The primary wavelength it uses, 254 nanometers, is dangerous to human skin and eyes if directly blasted at them. So, well, you don’t blast it directly at them. The next best thing is to put the lamps high up in a room, where they can kill pathogens at that height and spare the humans.
> The problem is that you can’t safely shine conventional 254 nm light at humans, much less at the wounds of humans who are recuperating from surgery. So Brenner and his colleagues, thinking about the donor’s challenge, arrived at the idea of trying out shorter wavelengths, 207 nm or 222 nm far-UV. Those wavelengths penetrate far less than conventional UV, and because of that, far-UV seemed much less likely to damage human skin or eye cells, while still being strong enough to kill viruses and bacteria.
This is precisely what's addressed by the article though. It's talking about far UV, which based on evidence to date does not cause any damage to skin or eyes. The ozone issue certainly needs more study, but I don't see the justification for labelling this an unreliable source. It seems like an accurate overview to me.
This is not a scientific journal, anyway I read the article and it is mix of unrelated sources:
- a test on certain UVC wavelength radiation on *MOUSES*
- a study of UVC filters for eye safety
That to conclude that we should use UVC as anti-virus measure.
Has the journalist a degree in biology or medicine ? Are his conclusion supported by a serious medical study , with peer review ?
* I don't think so, IMHO , is one that write stuff on Internet, so for someone he is a reliable source. OH PLEASE !!!
There's a lot of fake junk out there. The fake junk comes in two forms - UV lights that emit in dangerous parts of the spectrum, and UV lights so weak as to be at "homeopathic levels". Lamps that emit around 222nm are significantly more expensive than the wrong lamps.
Typical fake on eBay.[3]
Previously on HN: [2]
[1] https://www.nature.com/articles/s41598-020-67211-2
[2] https://news.ycombinator.com/item?id=34794273
[3] https://www.ebay.com/itm/394713677079