There's Light at The End of The Tunnel
There's Light at The End of The Tunnel
It's Far-UVC.
There's a technology that could change public health forever, but most of us don't know much about it yet.
We already use UV light in a handful of settings. We use it in medical and food production facilities, and some buildings already have what's called upper-room UV. There's a new form of UV light that could be safe in most public places. It just needs more testing, greater public awareness, and wider adoption.
It's called Far-UV, or Far-UVC.
An early pioneer, David Brenner gave a TED Talk on Far-UVC several years ago, even before the Covid pandemic, to combat the rise of drug-resistant superbugs. He envisioned a future with Far-UVC deployed in hospitals, airports, offices, and schools. He argued it was safe and cost-effective in the long run, and could be a valuable alternative or supplement to ventilation.
So, where is it...?
As Nicola Jane Boyd argues, western countries have eagerly embraced mRNA vaccines and accepted a marginal degree of risk (with the exception of anti-vaxxers). Meanwhile, "the bar was set considerably higher for Far-UVC, with ongoing precautionary evaluation hindering progress and widespread adoption."
We already know it works.
Is it safe?
As Boyd writes, UVC light at 254 nm "is an established 80-year-old technology that has been widely used in water disinfection, food decontamination, and the control of TB in hospitals and homeless shelters." It was starting to gain traction in the mid-20th century, but "fell out of fashion" as western societies adopted vaccines and antibiotics, opting to treat rather than prevent disease.
We can see a similar trend now, with public health voices routinely promoting vaccines and antivirals like Paxlovid while barely saying a word about masks or clean air. We know who benefits from that, don't we?
Clean air expert Joey Fox explains the different types of UV light. Both UVA and UVB light shine at wavelengths above 280 nanometers. These types of light illuminate the world, and they kill germs. They can also cause sunburns, skin aging, and cancer. Then there's UVC light at 100-280 nm and Far-UVC, at 200-230 nm.
Unlike UVC in general, Far-UVC at 200-230 and 222-230 nm in particular can't penetrate your eyes or skin. In fact, Far-UVC at 222 nm barely penetrates your dead skin cells, and most of it gets absorbed in the tear layer of your eyes, but it still kills germs. According to UVC researcher Ewan Eadie, "Far-UV exposure of 30,000 hours or 3.5 years is equivalent to 10 minutes in the sun."
So, not harmful.
You might wonder why we need Far-UVC technology if we already know about ventilation and HEPA filters.
Good question:
As an article in Scientific American explains, "Ventilation systems that replace air in a room are rarely powerful enough to fully protect against coronaviruses and other easily caught diseases." Air cleaning systems with effective filters work better, but they're often "expensive to install and operate, often noisy, and limited in reach. Multiple devices might be needed." With Far-UVC, you don't have to worry as much about air movement. As Edward Nardell with the Harvard Chan School of Public Health says, Far-UVC "is the only method that gives you this incredibly high number of equivalent air changes, because you can disinfect such a large volume of air at once."
You can look at more studies here:
How much equivalent air exchange?
According to Joey Fox, tests on products like Sterilray can sanitize the air in an entire room safely, as well or better than most air purifiers. With Far-UVC, "you can reach greater than 100 equivalent air changes per hour..." Studies on Far-UVC point to the same impact. When they're designed and installed by professionals, these systems can clear 90 percent or more of the airborne pathogens in a room in just minutes.
That's a huge win.
Most of us have spent the last several years working with HEPA purifiers and Corsi-Rosenthal boxes because they're familiar. We trust them. It's hard to hurt yourself with a HEPA filter. But they're not going to be the best solution for every space. That's why we need a both/and approach.
The co-founder of OpenAeros, M Pang, recently gave an online talk on Far-UVC where he explained the science behind the technology, as well as his recommendations on different brands and how to deploy these devices. With mask nerd Aaron Collins, he also founded the OSLUV Project, which specializes in making Far-UVC more affordable and accessible.
The highlights from his talk:
Far-UVC has a lot of potential once it's scaled up. Right now, we're still learning about best practices. It's expensive and difficult to conduct independent testing on Far-UVC devices. They're great at reducing long-range transmission, but they still struggle with short-range or near-field transmission. Basically, if you're standing right next to someone, nothing is going to protect you better than a quality mask like an N95. In most cases, Far-UVC offers an additional level of protection, and you don't want to use it as a total replacement for ventilation or filtration, unless you really know what you're doing.
In addition to the price, most of us are going to struggle to decide on something that's safe. Fortunately, groups like OpenAeros and OSLUV are testing and evaluating devices.
If you're like me, you've come across links and ads for various Far-UVC products, but you didn't know what to make of them. Experts like Nardell warn consumers "to proceed with caution" since "an appliance delivering the wrong wavelengths can do damage." And if it doesn't have enough juice, it won't deliver enough UVC light to actually kill any germs.
So, how do you shop for Far-UVC devices?
As Far-UVC advocate Michael Hicks says, "power is everything... What matters is the output, the irradiance, measured in milliwatts (mW) or microwatts (uW) per square centimeter at a given distance, typically a meter." Even with several smaller devices, "in anything bigger than a closet (literally), the aggregate kill rate is still going to be far too low to avoid breathing in a bunch of virus. This is why I don't recommend people plunk down $300+ for any of these lower-power devices. They provide a false sense of security while doing very little to protect you beyond a few inches from the lamp."
Hicks goes further:
If you're going to invest in this tech, do it right. The absolute minimum I'd consider would be something like the My Lumens UVPro222-B1, which uses the Ushio B1 Far-UVC module. If you have the money and you want a tool that'll do the job, invest in a Sterilray Sabre for portable needs or an Esconce for a fixed mount. They're extremely expensive, but I don't regret a penny that we spent on ours. It's saved us several times from almost certain infection.
This article by Hicks on Pandemic Enclave explains the basics of Far-UVC and what criteria to use when looking for a product. He specifically talks about the Ergo X-one, Krypton Shield, and the Sterilray Sabre.
There's a wide range of UVC products out there, but you have to remember the difference between UVC and Far-UVC. For example, I rigged up a decontamination unit for my groceries with a couple of UVC bulbs, clamp lamps, and curtain rods, but they're not Far-UVC bulbs. You can't just plug UVC bulbs into your light fixtures. That would be dangerous, and dumb.
You can use Far-UVC devices for different purposes. You can use them to disinfect entire rooms. You can use them to disinfect surfaces. Or you can use them to disinfect your phone. You'll find products specialized for these different uses. None of them are a substitute for the other.
If you're looking to buy Far-UVC products, Joey Fox also lists a handful of companies and some reviews here.
I've also been building a list.
Here's the deal:
Institutions should be adopting this tech at scale. It would work especially well in buildings and facilities where ventilation and air filters by themselves can't do the job.
We should also be establishing a more efficient and rigorous process to review these products, and we should be testing them to make extra sure they don't cause harm to vulnerable populations. It's one thing to say Far-UVC can't penetrate skin cells. It's another thing to offer the extra assurance that it's safe for vulnerable populations with sensitivity to different spectrums of light. We should especially emphasize that last part, before we install Far-UVC lights in public spaces.
On an individual level, Far-UVC will remain expensive and hard to find without a greater push for innovation. Most of us are already having to pay out of pocket for tests and masks. It's just not reasonable for us to shoulder this burden, too. We need institutional investment to make it cost-effective.
On that note, the public needs to start demanding better tools and access to those tools. It's ridiculous that instead of affordable, effective tests and clean air, we're instead being told to live with constant infection and illness, as if there's nothing to do about it.
We're not just facing a sustained threat from Covid. We're watching bird flu transform into a human pandemic in real time. Other diseases are surging 30 times stronger than pre pandemic norms, and all of this is trashing our immune systems.
We could have clean air. There's light at the end of the tunnel. We just have to get to the end of the tunnel.
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