Far-UVC Light Efficient and Safe versus Human Coronaviruses

Our new publication "Far-UVC light (222 nm) efficiently and safely inactivates airborne human coronaviruses", published in Scientific Reports, 10, Article number: 10285 (2020), demonstrates the ability of Far-UVC light to combat human coronaviruses.

In this publication, we examined two human coronaviruses, alpha HCoV-229E and beta HCoV-OC43, which have similar genomic size to the betacoronavirus SARS-CoV-2 which causes COVID-19. These coronaviruses (229E and OC43) were aerosolized and passed through our custom exposure chamber where they were exposed to far-UVC light at 222 nm. Low doses of 1.7 and 1.2 mJ/cm^2 inactivated 99.9% of aerosolized coronavirus 229E and OC43, respectively. As all human coronaviruses have similar genomic sizes (a key determinant of susceptibility to UV), far-UVC light would be expected to show similar inactivation efficiency against other human coronaviruses including SARS-CoV-2.

Based on the results, continuous far-UVC exposure in occupied public locations at the current regulatory exposure limit (~3 mJ/cm2/hour) would result in ~90% viral inactivation in ~8 minutes, 95% in ~11 minutes, 99% in ~16 minutes and 99.9% inactivation in ~25 minutes. 

Thus while staying within current regulatory dose limits, low-dose-rate far-UVC exposure can potentially safely provide a major reduction in the ambient level of airborne coronaviruses in occupied public locations, such as hospitals, transportation vehicles, restaurants, airports and schools.

This continues our work Using the Power of Light to help prevent the airborne spread of diseases.