TY - JOUR
T1 - Extreme Exposure to Filtered Far-UVC
T2 - A Case Study†
AU - Eadie, Ewan
AU - Barnard, Isla M. R.
AU - Ibbotson, Sally H.
AU - Wood, Kenneth
N1 - Publisher Copyright:
© 2021 The Authors. Photochemistry and Photobiology published by Wiley Periodicals LLC on behalf of American Society for Photobiology
PY - 2021/1/20
Y1 - 2021/1/20
N2 - 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 1500 mJ cm
−2; whereas, skin yellowing that appeared immediately and resolved within 24 h occurred with a 6000 mJ cm
−2 exposure. No erythema was observed at any time point with exposures up to 18 000 mJ cm
−2. These results combined with Monte Carlo Radiative Transfer computer modeling 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.
AB - 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 1500 mJ cm
−2; whereas, skin yellowing that appeared immediately and resolved within 24 h occurred with a 6000 mJ cm
−2 exposure. No erythema was observed at any time point with exposures up to 18 000 mJ cm
−2. These results combined with Monte Carlo Radiative Transfer computer modeling 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.
UR - http://www.scopus.com/inward/record.url?scp=85100354686&partnerID=8YFLogxK
U2 - 10.1111/php.13385
DO - 10.1111/php.13385
M3 - Article
C2 - 33471372
JO - Photochemistry and Photobiology
JF - Photochemistry and Photobiology
SN - 0031-8655
ER -