A group from University of Milan, etc. has reported on inactivation of SARS-CoV-2 with UV-C irradiation.
https://www.nature.com/articles/s41598-021-85425-w
Authors irradiated UV-C (254nm) on V6 cells with different Multipulicity of Infection (MOI). 0.05 MOI, 5 MOI, and 1000MOI. 0.05 MOI is equivalent to the low-level contamination observed in closed environments, 5 MOI corresponds to the average concentration found in the sputum of COVID-19 infected patients, and 1000 MOI is a very large concentration, corresponding to that observed in terminally diseased COVID-19 patients. In a range from 0.05 MOI to 5 MOI, a very small dose of 4 mJ/cm2 was enough to achieve full inactivation of the virus. Even at the highest value, 1000 MOI, virus was totally inactivated with a dose of 16.9 mJ/cm2.
