Far-UVC is a shorter wave length of UV light that is unable to penetrate the dead skin layers of the skin. Bacteria and viruses are smaller, therefore they are killed by this wavelength of UV light. It leaves the technology safer for people. Check out this video from USA Today:
Repetitive irradiation with 222nm UVC non-carcinogenic, safe for sterilizing human skin
here is an article pulled from Physics.org about the technology that we use. Kobe University and Ushio have tested this technology. check out the article here: https://phys.org/news/2020-04-repetitive-irradiation-222nm-uvc-non-carcinogenic.html