is 265 times the current exposure limit value of 23 mJ cm À2 at 222 nm. 7 Therefore, even at very high exposure doses, appropriately filtered far-UVC is unlikely to present a carcinogenic risk through direct DNA damage. These important but preliminary results are very encouraging. As recently advised and encouraged by the UK's Scientific Advisory Group for Emergencies we are continuing with multiple far-UVC research projects to investigate the efficacy and safety profile of this very promising technology. 8 However, to date, the evidence is overwhelmingly in favour of using filtered far-UVC as a safe, effective germicidal technology.