What is UV-C light?
UV-C or germicidal UV is part of the ultraviolet spectrum that can inactivate pathogens like bacteria and viruses. It utilizes specific wavelengths of the ultraviolet spectrum, typically between 200 to 280 nanometers.
How does germicidal UV kill viruses?
Germicidal UV products can actually change the DNA and RNA of bacteria and viruses, destroying their ability to reproduce.
Most UV-C products can inactivate up to 99.9% of pathogens including viruses, bacteria, mold spores, and fungus. Viruses are not technically living organisms, so germicidal UV technically "inactivates" viruses.
Since COVID-19 can live on certain surfaces for up to three days and can travel through the air, germicidal UV is a great tool to disinfect air and surfaces.
Although the science behind germicidal UV has been around for a long time, it hasn't been widely used in the U.S. until recently. The CDC and FEMA started to endorse the use in hospitals in the early 2000s. Since then, several medical reviews have noted the effectiveness and usage has jumped in the last 13 years.
Now, the technology is expanding to include new products that can work for a wide range of industries, not just hospitals.
Can UV light kill COVID-19?
A scientist from Columbia University says preliminary tests show that UV-C can inactivate COVID-19.
Dr. David Brenner performed tests on secure samples of SARS-CoV-2, the virus responsible for COVID-19. He exposed the samples to UV-C and measured the response after the exposure.
Dr. Brenner announced his results in a news conference with New York City's Metropolitan Transportation Authority (MTA). The MTA is starting a pilot program with PURO™ Lighting products, powered by Violet Defense™ Technology, to disinfect its buses, trains, and offices. Dr. Brenner said he used the same type of UV that will be used on the subway in his research.
Dr. Brenner says he will continue with more tests and have his researched peer reviewed.
Because the structure of COVID-19 is different from past viruses, this testing is extremely important.
It's also important to note germicidal UV does not replace other cleaning measures like dusting off surfaces. In fact, germicidal UV products cannot penetrate particles like dust, so dirty surfaces will cause effectiveness to drop.
Is germicidal UV light safe?
Similar to the UV-A and UV-B rays from the sun, exposure to UV-C can damage the skin and eyes. It's important to follow strict safety guidelines when the products are operation.
As a basic rule, germicidal UV lamps should not run when anyone is nearby. The IES says there are no reports of long-term damage from an accidental overexposure, but there can be painful temporary consequences.
Only trained workers should handle germicidal UV units and make sure the product is turned off before performing maintenance. Also, buy the right light bulb for the right fixture and follow product use guidelines from manufacturers.
Advantages of germicidal UV
Germicidal UV lamps are extremely effective and have several major advantages.
Pathogen kill rate – Tests show that germicidal UV products kill up to 99.9% of bacteria and viruses when used correctly. On top of that, bacteria and pathogens cannot become resistant to UV like they can certain antibiotics and antibacterial products.
Limited chemical exposure – UV-C works in place of potentially harmful chemicals. It's safe to enter a room after germicidal UV products disinfect the area, but it might be hard to breathe in a room that has just been sprayed down with chemicals.
Lighting configurations – There are multiple lighting configurations for germicidal UV light, including different types of fixture installation, mobile units, and industrial HVAC attachments. Mobile units are a great option for hospitals, airports, fire and police stations, and the hospitality industry because they're easy to move from room to room. Plus, mobile units are a budget-friendly option compared to installing fixtures in every room.
Can germicidal UV deteriorate materials or surfaces?
UV rays from the sun are known to damage materials – that’s why a toddler’s plastic toys left outside over the summer causes the colors to fade and the plastic to be more brittle.
Similarly, UV-C and broad spectrum products can damage materials over time. The critical difference to look for is whether the UV radiation is constantly on or gives short bursts or pulses of disinfecting UV rays.
In most cases, constant UV rays will cause mainly cosmetic damage on objects or surfaces. For example, a white PVC pipe can change to a tan or brown color, but still maintain its structural integrity.
The germicidal UV fixtures made by PURO™ Lighting, powered by Violet Defense™ technology, are a good example of a disinfecting fixture that gives periodic bursts of broad spectrum UV to disinfect surfaces with minimal impact on the materials in the space.
World Health Organization www.who.int
Center for Disease Control www.cdc.gov
BBC Can you kill coronavirus with UV light? www.bbc.com
Live Science what is UV light www.livescience.com
UVC Resources FAQ www.uvresources.com
Klaran University about UVC www.bbc.com