Far-UVC light destroys 99.98% of harmful pathogens in the air and on surfaces. Unlike conventional UV-C sources, it is safe to use within occupied spaces. Its shorter wavelength means it cannot penetrate human skin or eye cells, but is still effective at killing bacteria and viruses.
Studies into the safety and efficacy of this technology are increasing, catalysed by the need for effective workplace solutions brought on by the ongoing COVID-19 pandemic. We have summarised the outcomes of some key studies below, demonstrating that the technology is a powerful tool that can help us battle the current pandemic, and the next.
Far-UVC light: A new tool to control the spread of airborne-mediated microbial diseases (Welch et al., 2018)
- Far-UVC efficiently inactivates airborne aerosolized viruses with a very low dose of 2mj/cm2 of 222nm light
- Continuous very low dose-rate far-UVC light in indoor public locations is a promising, safe and inexpensive tool to reduce the spread of airborne-mediated microbial diseases
- 222nm light showed the same bactericidal properties of 254nm light but without the associated skin damage
- Far-UVC light (222nm) might be a convenient approach to prevent transmission of drug-resistant infectious agents in the clinical setting
Far-UVC light (222nm) efficiently and safely inactivates airborne human coronaviruses (Buonanno et al., 2020)
- Low doses of 1.7 and 1.2 mJ/cm2 inactivated 99.9% of aerosolized coronavirus
- Far=UVC light would be expected to show similar inactivation efficiency against other human coronaviruses including SARS-CoV-2
- 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
Exploratory clinical trial on the safety and bactericidal effect of 222-nm ultraviolet C irradiation in healthy humans (Fukui et al., 2020)
- A 222-nm UVC at 500 mJ/cm2 was a safe irradiation dose and possessed bactericidal effects.
- In the future, 222-nm UVC irradiation is expected to contribute to the prevention of infection.
Predicting airborne coronavirus inactivation b far-UVC in populated rooms using a high-fidelity coupled radiation-CFD model (Buchan, Yang & Atkinson, 2020)
- Disinfection rates are increased by a further 50-80% when using far-UVC within currently recommended exposure levels compared to the room’s ventilation alone
- Far-UVC lighting could be employed to mitigate SARS-CoV-2 transmission before the onset of future waves
- This is particularly significant in poorly ventilated spaces where other means of reduction are not practical, e.g. social distancing
- Filtering longer ultraviolet wavelengths is critical for the human skin safety of far-UVC devices
- Contributes to the growing arguments for the exploration of exposure limit expansion, which would subsequently enable faster inactivation of viruses
- MRSA bacteria in different concentrations on blood agar plates were inactivated with irradiation doses in the range of 15-40 mJ/cm2
- LED-based far-UVC lamps could soon be used in everyday clinical practice to eradicate multiresistant pathogens directly on humans
As more studies emerge, we expect the technology to become more prevalent across the globe.