Ultraviolet light, or UV light, has been used to kill off germs and viruses in the past. But can the high-energy light waves do the same for COVID-19, and is it safe?
Barry Hunt is the Founder and CEO of PrescientX, a health-care equipment company in Canada that is leading the use of UV-Light devices. Hunt said UV 254 is the most common germicidal wavelength that is used currently.
“Ultra violet light covers the spectrum of short wavelengths, visible wavelengths that we can see - the shorter they get, the more visible they become,” Hunt said. “UV light that we use now for disinfection is actually invisible. We see a little bit of an indigo blue glow, but that’s from other wavelengths being used at the same time.”
He said that UV LEDs are becoming more popular because they are effective when in close prose proximity to a specific surface, dealing with areas that are within a foot’s distance. But he said, unfortunately, the LEDs don’t have the power or efficiency to deliver strong UV over longer, denser spaces – that’s where fluorescent technology comes into play.
“So for example you can have upper air UV lights that are located on walls that are eight feet or higher in a room, and they will provide a field of UV high up in that room. So any air or any viruses that are passing down through that field, or straight up into that field, will be disinfected.”
Hunt said that when using the UV light to disinfect a surface or area, the amount of time that it needs to clean that area can range from one second to one minute, depending on how much of the infection is on that surface.
Hunt said that because UV light is very powerful, the exposure limit is very brief. Therefore, people should avoid coming in contact with UV waves when being used, if possible.
“The dose that you’re receiving is a measure of the intensity,” Hunt said. “And the closer you are to a UV source, the more intense it is.”
However, Hunt said that using any type of glass or plastic protective equipment can protect people from UV rays, including regular eyeglasses or goggles.
Hunt’s company has looked into using UV light to disinfect N95 masks, which are greatly needed in the healthcare industry.
“But to do that we’d have to penetrate the layers of the mask with UV light, which is very difficult to do,” Hunt said. He said, however, it is simple to clean the outer surface of the masks.
PrescientX won a World Patient Safety Innovation award in 2017 for its work in building infection prevention technology for healthcare facilities, and has since expanded its products into sites like airports and grocery stores, which can use to sanitize their facilities from COVID-19.