Assessing the safety of new germicidal far-UVC technologies

Maximilian Görlitz, Lennart Justen, Patrick J Rochette, Manuela Buonanno, David Welch, Norman J Kleiman, Ewan Eadie, Sachiko Kaidzu, William J Bradshaw, Emilia Javorsky, Nigel Cridland, Anat Galor, Martin Guttmann, Martina C Meinke, Johannes Schleusener, Paul Jensen, Per Söderberg, Nozomi Yamano, Chikako Nishigori, Paul O'MahoneyDieter Manstein, Rodney Croft, Curtis Cole, Frank R de Gruijl, Paul Donald Forbes, Stephen Trokel, John Marshall, David J Brenner, David Sliney (Lead / Corresponding author), Kevin Esvelt (Lead / Corresponding author)

Research output: Contribution to journalReview articlepeer-review


The COVID-19 pandemic underscored the crucial importance of enhanced indoor air quality control measures to mitigate the spread of respiratory pathogens. Far-UVC is a type of germicidal ultraviolet technology, with wavelengths between 200 and 235 nm, that has emerged as a highly promising approach for indoor air disinfection. Due to its enhanced safety compared to conventional 254 nm upper-room germicidal systems, far-UVC allows for whole-room direct exposure of occupied spaces, potentially offering greater efficacy, since the total room air is constantly treated. While current evidence supports using far-UVC systems within existing guidelines, understanding the upper safety limit is critical to maximizing its effectiveness, particularly for the acute phase of a pandemic or epidemic when greater protection may be needed. This review article summarizes the substantial present knowledge on far-UVC safety regarding skin and eye exposure and highlights research priorities to discern the maximum exposure levels that avoid adverse effects. We advocate for comprehensive safety studies that explore potential mechanisms of harm, generate action spectra for crucial biological effects and conduct high-dose, long-term exposure trials. Such rigorous scientific investigation will be key to determining safe and effective levels for far-UVC deployment in indoor environments, contributing significantly to future pandemic preparedness and response.

Original languageEnglish
Number of pages20
JournalPhotochemistry and Photobiology
Early online date6 Nov 2023
Publication statusE-pub ahead of print - 6 Nov 2023


  • 222 nm
  • COVID-19
  • biosecurity
  • far-UVC
  • germicidal ultraviolet
  • indoor air quality
  • pandemic preparedness
  • ultraviolet

ASJC Scopus subject areas

  • Biochemistry
  • Physical and Theoretical Chemistry


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