UVC has been known for more than 100 years now to be really, really good at killing microbes, bacteria and viruses both.
Ultraviolet light is part of the electromagnetic spectrum, which includes things like gamma rays, x-rays, infrared light, microwaves, visible light and radio waves.
Ultraviolet light is grouped into three categories based on the light’s wavelength. There’s ultraviolet A, ultraviolet B and ultraviolet C. The sun produces all three types of UV radiation, but we only experience A and B on Earth’s surface.
UVC does not penetrate the clouds, so it doesn’t hit us here on Earth. UVA and UVB light do. That’s why people go outside and they can get sunburns and things like that. So everybody’s familiar with the power of ultraviolet light.
Within the spectrum of ultraviolet light, UVC, which sits at 200 to 280 nanometers, is in the germicidal disinfecting range.
What we experience as sunlight here on earth is mainly UVA and a little bit of UVB. And they are actually much less efficient at killing microbes than UVC. UVC is by far the more efficient way of killing microbes.
We know that ultraviolet light is effective against many different kinds of viruses, many types of bacteria and even some very hardy bacteria that can produce spores with thick coatings on them. Ultraviolet light can be effective against those and effective against fungus also.
UVC light can be quite dangerous. It can burn exposed skin and damage your retina. The World Health Organization issued guidance not to use UV lamps to sterilize hands or other parts of the skin.
The issue with UVC, though, is that it’s a health hazard. So you can really only use it when people are not around.
UVC light interferes with and destroys the nucleic acids, the DNA or RNA, of bacteria, viruses and other microbes.
What it does is it causes chemical bonds that aren’t supposed to be there to form within the genes of the microbe. And those new chemical bonds prevent the microbe from replicating. And because the microbe can’t replicate any longer, it effectively kills it off.
It breaks open the protein shell of a pathogen. So imagine a pathogen and everybody’s seen a cell under a microscope. Imagine it like an egg and you’re cracking an egg. And once you’ve cracked the egg, you can’t put the egg back together. That’s what we’re doing o n a microscopic level.
Ultraviolet light can kill microbes in many different environments. It has been used for several decades to disinfect drinking water, wastewater, air, pharmaceutical products and surfaces against the whole suite of human pathogens.
Despite all of its uses, there are a few things that limit its effectiveness.
If there is organic material, so if there’s essentially dirt on a surface, the dirt impacts how much of that ultraviolet C light is able to get to the microbes. And because of that, it works best if the surfaces are cleaned first and then the surfaces are exposed to the UVC light.
Another important point is that if you try to disinfect a room with UVC Light and you have, let’s say a telephone sitting on a bedside table, the area under that telephone is not going to be effectively decontaminated.
UVC light has been used to combat other coronaviruses such as MERS and SARS, and it was used against Ebola. It’s been proven effective and is expected to also work against the SARS-CoV-2, the virus that causes Covid-19.
Because we know it’s effective against the coronavirus family and there’s structural similarities between all of the viruses in the coronavirus family, everybody expects that ultraviolet C light will be very effective against the SARS-CoV-2 virus.
UVC light has been increasingly used in health care environments to prevent infections in hospitals.
As we started to see more drug resistant bacteria and drug resistant fungus, there is really a growing interest in the use of ultraviolet C light to help disinfect our health care environments.
Xenex is one company that built a UVC robot to sanitize hospital rooms. The company says its LightStrike robot is disinfecting somewhere in the world every 4.7 seconds.
Just in the United States, 2 million people a year go to the hospital and get an infection from going to the hospital. And then 100,000 of those 2 million die each year from those infections. In the hospitals that have used our robots, they’re dropping their infection rates 50%, 70%, even 100%.
That’s really what we focus on, is how do we reduce the infection rates and make it the hospitals a safer place for patients to go.
UV light is efficient as a disinfectant tool and it just needs electricity to work. As long as they have the robot and a box of bulbs, they can take energy, electricity and convert it into disinfection. It’s faster and less labor intensive than cleaning by hand. It also reduces the need to clean with powerful chemicals.
So you could just use more bland soaps for the cleaning and then rely on UVC for a chemical free disinfection. It’s hard to get to all the surfaces in a 15 or 20 minute room turnaround time.
The second thing is, is the chemicals end up being very corrosive on the surfaces. You need to leave surfaces visibly wet for several minutes to kill viruses. They’re only to be used on hard, non-porous surfaces and they’re also only to be used in well ventilated areas.
Cleaning staff can also miss areas.
There was a number of studies that came out in the early 2000s showing that housekeepers, and they do an incredible job. They would miss about half of the high touch surfaces.
One other thing that’s worth adding is there’s been recent publications that have demonstrated that in Italy, the hospitals actually became the agents of infection. So the hospitals were so pathogenic that they were passing the pathogen from patient to patient.
Ultraviolet light could be a powerful tool in the fight against Covid-19. And in some instances, it’s already being used. China is disinfecting entire buses with UV light and banks are using UVC on currency.
The Pittsburgh International Airport became the first airport in the U.S. to deploy autonomous cleaning robots equipped with ultraviolet lights for disinfection.
Dimer has a device designed specifically to disinfect planes called the Germfalcon. It’s the size of a drink cart and has articulating arms that extend over the plane’s seats.
Using ultraviolet C lights like they use in hospitals. You push it up and down the aisle, the wing hovers over the seatback tops and you can disinfect the whole plane really quickly.
Dimer claims it can kill 99% of germs in three minutes and that it takes 30 to 45 minutes to clean an entire wide body airplane. We’re primarily focused on viruses like Influenza, Norovirus, Ebola. And right now we’re dealing with coronavirus.
UVD Robots makes the only fully autonomous UVC disinfection robot on the market. After mapping out the environment, it moves around autonomously guided by Lidar. The company claims it can kill 99.9% of bacteria and viruses in 10 to 15 minutes, and its robots are dispatched in over 50 countries around the world.
There are some newer products that we are already seeing in use in some areas outside the United States, where it’s essentially a Roomba-like device with ultraviolet C bulbs on it. It’s able to autonomously navigate into a room and treat that room.
Texas-based Xenex has a UV robot called LightStrike. It delivers germicidal UV from 200 to 315 nanometers, killing bacteria and viruses in five minutes. And the company recently verified that its robot is effective against SARS-CoV-2.
It puts out the entire spectrum of germicidal light. And by doing that, different germs, different pathogens are more vulnerable to different wavelengths of light. Because it’s broad spectrum, no matter where they’re vulnerable, a LightStrike robot will get them.
Xenex is sending its robots to China and Italy, as well as using them in Houston. The company says it has thousands of robots already in operation and is ramping up U.S. production.
Before the Covid crisis, we already had over 500 hospitals with thousands of robots around the world. Covid hit and all of our international partners really started calling us right away. And we started shipping 50 to Italy and 30 to Japan, Singapore. All of these countries were really hard hit by Covid infections before the United States experienced it.
Since then and as the cases have grown in the United States, both our existing customers and new customers have come to us to use this. Hospitals need it and they’ve been requesting it like unbelievable amounts.
The CDC and the International Ultraviolet Association are looking at how UVC could be used to disinfect PPE at hospitals, extending the life of disposable masks.
Xenex is the first manufacturer to verify with 3M that its masks are safe after being disinfected with its LightStrike robot. 3M had issued guidance against using other UV devices on the masks. We sent them our device. They tested our device. They said we didn’t cause material damage. They passed the use of Xenex for N95 masks.
There are even consumer products on the market like UVC water bottles, small light wands and disinfectors for phones. But one of the biggest challenges we face is how to keep public, high traffic areas clean.
As we get back to work in the next few months and we’ll be in rooms much closer to each other than we were before. There’s a concern again about transmission of viruses from one person to another.
UV robots are effective, but they can only be used in the absence of people. There is, however, promising potential for a new breakthrough in ultraviolet tech that could help.
Researchers are experimenting with a shorter wavelength type of UVC, which could be safe for human exposure but still effective against microbes.
This is light with a wavelength of 222 nanometers. And it’s been shown to be not only effective against microbes, but also it’s been shown, I think fairly convincingly, to be safe to even have people potentially in that environment where that light is being used.
What we’ve been working on is a type of UVC light which not only will kill viruses, but is safe for human exposure. This technology was initially developed to help mitigate the spread of influenza, but it’s expected to be effective against SARS-CoV-2.
So our first studies were with these seasonal coronaviruses. And in fact, the far-UVC light was very efficient at killing them. And our next step, which is actually what’s been going on at the moment, is to look at these SARS-2 virus. The virus that’s actually causing the current crisis.
There’s no reason to think that they will respond any differently from any other coronavirus. So we’ve every expectation that far UVC light will kill the current coronavirus.
Far-UVC lights are in the process of being tested on mice and initial safety results are promising. We use what are called hairless mice. These mice have been sitting in the UVC light for nearly a year now. We give them skin tests every couple of weeks. We give them eye exams every couple of weeks. And absolutely nothing, they’re perfectly fine.
Far- UVC lights could be permanent fixtures in public places like offices and airports to prevent the spread of viruses and other microbes. The sorts of public spaces we have in mind are hospitals, subways and trains and planes and buses, restaurants, for example, food stores. Anywhere where people are going to be clustered in the same room.
The main roadblock at the moment is producing the lamps.
The problem is how do you scale it up right now to the level where you make it a practical technology? There are a couple of companies at the moment that are really ramping up to produce large numbers of these lamps. But I think it will be the autumn before the lamps are produced in really large numbers. And the sorts of numbers we’re talking about are hundreds of millions.
Costs could be high at first until large scale manufacturing helps bring it down. Maybe we’ll be in time for the famous bubble of the Covid-19 crisis if it really happens. And we’ll certainly be in time for the next Influenza epidemic next year. And we’ll certainly be in time for the next pandemic whenever it should occur.
We’ve seen a huge amount of interest from places like hotels, from gymnasiums, from schools, from office buildings. People have wanted to disinfect ambulances. We’ve seen a lot of interest from airports and airlines.
And not to mention old age homes, nursing homes, skilled nursing facilities. Covid has really brought the importance of disinfection home to almost everybody all over the world.
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