How UV Works

UVC Light:

Most of us are familiar with the UVA and UVB bands of light naturally produced by our sun. We use UVA & B blocking sunscreens and wear UVA & B protective sunglasses to shield ourselves from these potentially harmful rays. But did you know there is also a third band of naturally occurring UV light, called UVC?

You may be in the dark about UVC light because it’s actually filtered out by the ozone layer in our atmosphere and never makes it to the earth’s surface. And it’s a good thing too! UVC light is germicidal by nature, obliterating any cell’s DNA by passing through the cell’s nucleus and colliding with the DNA inside. Once their DNA is shattered, harmful microorganisms like bacteria, viruses, protozoa, or fungi are effectively neutralized.

UVC History:

For nearly a century, UV mercury lamps were considered the best (and only) choice for producing UVC light for disinfection devices. They were able to produce UVC light at 254 nm, which was the only germicidal wavelength known at the time. However, mercury lamps have severe limitations including high power consumption, low light output at refrigeration temperatures, fragile fused silica (glass) construction, long warm-up time, high risk of harmful mercury exposure, unwanted production of toxic Ozone (O3), and limited UV emittance at only 254 nm. These limitations pushed researchers to develop new methods for producing UVC light.

Enter the UVC LED!

Research efforts into “Deep UV LED” technology over the past decade saw the award of the Nobel Prize in physics in 2014 and demonstrated that the most effective germicidal UVC wavelengths peak between 260 nm and 270 nm instead of the 254 nm wavelength produced by the LEDs mercury bulb predecessor. The breakthrough development of Deep UV LEDs also brought with it a myriad of technical advantages. The combination of high output power, low power consumption, compact size (3.5mm X 3.5mm), and superior durability and has enabled designers to develop smaller yet more powerful, rugged, and reliable devices.

“The research by the National Emerging Infectious Diseases Laboratories (NEIDL) at Boston University demonstrates that SARS-CoV-2 can be effectively inactivated in a matter of seconds through exposure to low doses of UVC light in the key germicidal range,” said Larry Felton, President of Crystal IS, the supplier of our UVC LEDs.