Extreme exposure to filtered far-UVC : a case study
Abstract
Far-UVC devices are being commercially sold as "safe for humans" for the inactivation of SARS-CoV-2, without supporting human safety data. We felt there was a need for rapid proof-of-concept human self-exposure, to inform future controlled research and promote informed discussion. A Fitzpatrick Skin Type II individual exposed their inner forearms to large radiant exposures from a filtered Krypton-Chloride (KrCl) far-UVC system (SafeZoneUVC, Ushio Inc., Tokyo, Japan) with peak emission at 222 nm. No visible skin changes were observed at 1,500 mJcm-2, whereas skin yellowing that appeared immediately and resolved within 24 hours occurred with a 6,000 mJcm-2 exposure. No erythema was observed at any time point with exposures up to 18,000 mJcm-2. These results combined with Monte Carlo Radiative Transfer computer modelling suggest that filtering longer ultraviolet wavelengths is critical for the human skin safety of far-UVC devices. This work also contributes to growing arguments for the exploration of exposure limit expansion, which would subsequently enable faster inactivation of viruses.
Citation
Eadie , E , Barnard , I M R , Ibbotson , S H & Wood , K 2021 , ' Extreme exposure to filtered far-UVC : a case study ' , Photochemistry and Photobiology , vol. Early view . https://doi.org/10.1111/php.13385
Publication
Photochemistry and Photobiology
Status
Peer reviewed
ISSN
0031-8655Type
Journal item
Collections
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.