Far-UVC Light: the human friendly UV-C radiation that kills 99.9% of coronaviruses
Recent study carried out by researchers at Columbia University Irving Medical Center, has used far-ultraviolet C(UVC) light, at a wavelength which is safe for humans, to kill more than 99.9%of coronaviruses that are found present in airborne droplets. UVC radiation can destroy the outer protein coating of the SARS-Coronavirus. The destruction ultimately leads to inactivation of the virus. Before we dive deep into the study, let’s understand the basic of UV-C light.
Whatis Far-UVC Light?
Currently, the viruses can be killed by conventional germicidal UV-C light at a wavelength of 254 nm. However, this wavelength is not safe for humans and can be a health hazard to skin and eyes. For this study, the researchers tested at using far-UVC light at a wavelength of (207–222 nm), which cannot penetrate through the eye or the outer, dead layer of skin–meaning it efficiently kills pathogens potentially without harm for human tissues. The researchers believe that far-UVC light will be safe to use in occupied indoor public places to reduce the risk of transmission and infection of COVID-19.
How does Far-UVC Lightkill Coronaviruses?
To investigate the efficacy of far-UVC light for killing coronaviruses, the researchers used a misting device to aerosolise two common coronaviruses, which were then flowed through the air in front of a far-UVC lamp. They then tested to see how many were still active –finding that 99.9% of the viruses had been killed by a very low exposure.
The researchers believe that continuous exposure to the far-UVC light would kill 90% of airborne viruses in about eight minutes, 95% in 11 minutes, 99% in about 16 minutes, and 99.9% in 25 minutes.
“Far-UVC light doesn’t discriminate between coronavirus types, so we expected that it would kill SARS-CoV-2 in just the same way,” Brenner said. Since SARS-CoV-2 is largely spread via droplets and aerosols that are coughed and sneezed into the air it’s important to have a tool that can safely inactivate the virus while it’s in the air, particularly while people are around.
“Because it’s safe to use in occupied spaces like hospitals, buses, planes, trains, train stations, schools, restaurants, offices, theatres, gyms, and anywhere that people gather indoors, far-UVC light could be used in combination with other measures, like wearing face masks and washing hands, to limit the transmission of SARS-CoV-2 and other viruses, ” he added.