The Null Effect of UVC Ceiling Light Exposure on SARS-CoV2

There has been some extensive research investigating the effect of Far Ultraviolet Radiation (UVC) on SARS and MARS. However, to the best of our knowledge, there have not been any detailed experiments looking at the effect of UVC on COVID-19 (now is called SARS-CoV2). Many researchers in this field believe that UVC destroys SARS-CoV2 because it warps the genetic material of the virus hurdling the viral particles from reproduction. In this paper, we report the result of our novel experiments on the effect of UVC on SARS-CoV2 using a commercially available UVC source, i.e. Krypton Disinfection lighting CM15W12V Series (wavelength of 222 nm), which is sold and marketed for the disinfection of pathogens. The experiments were extended to study the effect of UVC exposure to Bacteria and Fungus. Our experiments show that UVC has no effects on SARS-CoV2 when it is close to the SARS-CoV2 culture plate (4 - 5 cm) or at a distance (2.0 to 2.9 m), i.e. when fixed at the ceiling. This observation is important as the public seems to have the impression that commercial UVC ceiling light can kill SARS-CoV2 while this study has proven the opposite. Moreover, it shows no effect even when the UVC ceiling light is radiating on SARS-CoV2 for overnight. This proves that the intensity of the UVC from these devices is relatively low. However, the UVC light is found to be effective in destroying Bacteria and Fungus (part of pathogens), substantially, in 30 sec, and completely kills them when it’s at 2.9 m (or less) away from them and exposure for one day. This indicates that the UVC light is effective for bacteria disinfection.