INFOGRAPHIC: How Exactly Does UV-C Light Clean?

When it comes to UV-C technology, it may seem impossible that it a) actually exists and b) works. Just like electricity, ultraviolet radiation is as old as the universe, and something that humans – once we discovered it and understood it – have harnessed to make our lives better and safer.

Though it may seem like a space-age technology. The use of UV light for the purposes of sanitation is actually a very old one. It was initially discovered by Niels Ryberg Nilsen, a Danish physician who sought to examine the power of UV light to cure his own maladies. It was his discoveries on UV wavelengths and the human body that led to his being awarded the 1903 Nobel Prize for Physiotherapy.
Since its initial discovery way back in 1878, it had been used in countless landmark applications related to human health, including:
The first UV sanitation of a public water supply in Marseille, France in 1908.
The first hospital-grade germicidal UV lamps created by Westinghouse in 1932.
The first application in air-sterilization by GE in the 1950’s, a large contributor to the eradication of the scourge of tuberculosis.
It’s use against disease has even led to incredible discoveries about the very nature of disease, because it wasn’t until the 1930’s that the true germicidal potential of UV-C light first came to…well…light.
Ultraviolet light has been used to stop pathogens in their tracks for decades. But does it work against SARS-CoV-2, the virus behind the pandemic?
The short answer is yes. But it takes the right kind of UV in the right dosage. In other words, many at-home UV-light devices claiming to kill SARS-CoV-2 might not make the cut, and for the consumer, a comprehensive understanding of the technologies at play is essential to ensure that the product you’re using is not only effective, but safe.
What is UVC?
UV radiation can be classified into three types based on wavelength: UVA, UVB and UVC. Nearly all the UV radiation that reaches Earth is UVA, because most of UVB and all of UVC light is absorbed by the ozone layer, according to the Centers for Disease Control and Prevention. And it’s UVC, which has the shortest wavelength and the highest energy, that can act as a disinfectant.
By harnessing a small subset of the UV spectrum (280nm-100nm) UVC light represents a uniquely germicidal form of light that literally scrambled the very DNA that allows germs and bacteria to not only exist, but proliferate. Viruses can’t produce on their own, but they can pass down that genetic material: their DNA (or RNA). So they reproduce by finding cells and injecting their DNA into them, allowing them to infect that cell and continue along as that cell reproduces over and over. It’s what viruses and bacteria pass on, and what UV-C light effectively does is scramble these strands, stopping contamination in its tracks.

And it’s effective, in laboratory testing, UVC light has been found to stop 99.9% of the things that can make us sick in their tracks, and it does it all without the use of harsh chemical cleaners or solvents.

So…Does It Kill Coronavirus?

For those of us living through the pandemic – which, let’s face it, is all of us – the answer is yes. While UVC light is known to be germicidal, eliminating 99.9% of bacteria and germs on surfaces, in water and in air, rigorous testing in hospital environments has revealed that – as is the case with other coronaviruses – UVC light’s germicidal power applies to SARS COV-2.

But before you go and start bathing everything you own in UVC light, it’s important to know that it is not a replacement for common-sense cleanliness and best-practices. Since it’s inadvisable to use it on your bare skin, practices like using alcohol- based sanitizers and diligently washing your hands with warm water and soap still apply. Still, UVC technology represents a highly effective tool in the arsenal against this still-mysterious and deadly virus.