A Hiroshima University research team became the first in the world to discover that using ultraviolet C light with a wavelength of 222 nanometers — which is safe to use around humans — effectively kills SARS-CoV-2, the virus that causes COVID-19, aka coronavirus.
Other studies involving the safer UVC, also known as Far-UVC, have so far only looked at its ability to eradicate several seasonal coronaviruses that are similar to the SARS-CoV-2, but not on the COVID-19-causing virus itself.
The more damaging 254 nm UVC germicidal lamps, which are increasingly used in disinfecting health care facilities, should only be used to sanitize empty rooms, since they can harm exposed human tissues.
The safer 222 nm UVC cannot penetrate the outer, nonliving layer of the human eye and skin so it won't cause harm to the living cells beneath.
The study, published in the American Journal of Infection Control, showed almost all — 99.7% — of the SARS-CoV-2 viral culture was killed after a 30-second exposure to 222 nm UVC irradiation.
Researchers noted that further studies are needed to study the safety and effectiveness of 222 nm UVC irradiation in killing SARS-CoV-2 viruses in real-world surfaces, as opposed to their studies, which took place in a laboratory.
Source: Newswise Sept. 17, 2020