Does UV-C lighting kill coronavirus?
There’s a lot we still need to learn about the novel coronavirus. To date, there have not been any studies published on the effectiveness of UV-C disinfection lighting specifically on the novel coronavirus SARS-CoV-2. However, there have been extensive studies on the ability of UV-C germicidal lighting to kill or inactivate very similar pathogens.
There are (3) classes of viruses in regards to levels of resistance to disinfection:
- Class 1 – Small, non-enveloped viruses (<50nm). Class 1 viruses are considered “highly resistant” to disinfection and are the HARDEST to kill. This group includes norovirus (caliciviridae).
- Class 2 – Large, non-enveloped viruses. Class 2 viruses are considered “less resistant” to disinfection and are LESS HARD TO HILL. This group of viruses includes reoviridae and adenoviridae.
- Class 3 – Enveloped viruses. These are considered the “least resistant” to disinfection and are the EASIEST TO KILL. This group includes ebola, influenza, and coronaviridae (coronavirus).
According to the CDC’s Emerging Viral Pathogen Protocol, there needs to be validation that a product can inactivate at least one large or one small non-enveloped virus to be eligible for use against an enveloped emerging viral pathogen. What does this mean? If the UV light system has validation that it can kill a class 1 virus, it can claim to kill class 3 viruses, which include coronavirus.
There are several manufacturers of UV-C disinfection lighting systems that have completed the necessary testing to validate their claims to the ability to kill the various classes of virus; make sure you confirm with your supplier the UV disinfection lighting system that is most appropriate for your facility. This hospital in Nebraska is already using UV disinfection lighting (specifically UVGI) to kill coronavirus on PPE.
“While our experts say there haven’t been conclusive tests showing that UV light can kill the coronavirus, Berezow says “UV light kills everything: bacteria, fungi, viruses. It should kill coronavirus.” What we do know for sure is that it is effective against other viruses like the flu.)”
What viruses, pathogens, and bacteria does UV lighting kill?
Germicidal UV lighting can kill up to 99.9% of pathogens and has been used to successfully kill anything from tuberculosis to the common cold to the flu virus.
How does UV lighting help with "superbugs"?Superbugs are strains of viruses, bacteria, and other pathogens that have developed a resistance to antibiotics and other medications used to treat the diseases and infections they cause. UV-C lighting can be a lifesaver here because viruses and bacteria cannot resist its germ-killing effects whereas pathogens can learn to resist antibiotics and even chemical cleaners. This Duke University study notes that UV lighting was able to cut transmission of superbugs when other methods failed.
Also, According to this from the Centers for Disease Control (CDC), “UV can kill all bacteria, including drug-resistant bacteria because UV light is actually attacking the DNA and RNA of microbes. While the amount of UV needed to kill a microbe may vary as there is a relationship between the size of DNA molecules and the effect of UV radiation, there have been no reports of microbes demonstrating an ability to build an immunity to light-based methods.”
How does manual cleaning compare to UV lighting's "cleaning"?
You may be wondering why we can’t simply manually disinfect with cleaning products like bleach or even hydrogen peroxide. Firstly, water and air simply can’t be disinfected this way for obvious reasons. It’s true that water can be disinfected using chemicals, namely chlorine, but this comes with its own risks.
Surfaces can certainly be manually cleaned, but human error can lead to the spread of bacteria when cleaning isn’t executed properly. Also, manual chemical cleaners can damage certain surfaces, and chemical cleaners most definitely damage the integrity of PPE where appropriately administered UV-C lighting has minimal adverse effects. Manual cleaning may also miss bacteria in hard to reach areas (like in this study, where UV light was able to cut transmission of superbugs in hard to reach areas), whereas lighting can reach those spots.
Ideally, UV disinfection lighting is combined with manual cleaning like in this study, which shows that manual cleaning combined with just two minutes of ultraviolet light reduce bacterial load by at least 70%.
UV lighting can’t replace regular hygiene practices, but is a successful complement to these strategies.