In the last 6 months across social media, one particular technology that has been generating attention is UVC light and UVC robots. Through these exchanges, the effect of Ultraviolet-C light, it is safe to say has been somewhat exaggerated, sometimes beyond any science and practicality.

Due to the application of some fantastic sales and marketing strategies, the technology went from the ability to kill a virus in 20 minutes in a highly protected environment to be able to kill a virus in seconds, with no harm to humans. Unfortunately, this excitement does not come without a negative impact on the global fight against COVID-19.

Ultraviolet germicidal irradiation is a disinfection method that uses short-wavelength (UVC, commonly referred to wavelengths between 200 – 280 nm) light to kill or inactivate microorganisms by destroying nucleic acids and disrupting their DNA, leaving them unable to perform vital cellular functions.

Actually UVC kills viruses, proven to be an effective method of killing microorganisms, however when evaluating the use of UVC disinfection in public spaces, it comes with its own set of problems and considerations:-

UVC robots may not be able to be used practically in public areas to kill microorganisms effectively.
Safety requirements, accidently circumvented, disregarded or not understood, present a potential hazard to people.
Exposure times required to kill a virus at a long distance at times makes it impractical.

Recommendations:-

Organisations continue to clean and sanitise public areas with a chemical solution. UVC does not replace chemical sanitisation, UVC disinfection augments existing effective processes.
In general, remember that UVC requires long exposures with the appropriate system - if exposure is long enough to kill a virus, it’s also harmful to you

Healthcare professionals and researchers have already shown how UVC can kill microorganisms—its use has to be combined with a chemical cleaning process, with the appropriate UVC exposure time and with the appropriate safety protections. UVC solutions that do not meet those criteria are not only ineffective, they also add barriers to our real fight against COVID-19.

I would say that the right equipment used correctly will certainly enhance any infection prevention regime.

Some good peer review and useful information follows:-

(1) Evaluation of an Ultraviolet C (UVC) Light-Emitting Device for Disinfection of High Touch Surfaces in Hospital Critical Areas (Beatrice Casini & al, 2019) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6801766/

(2) Comparison of UV C light and chemicals for disinfection of surfaces in hospital isolation units. (Andersen BM & al, 2006) https://europepmc.org/article/med/16807849

(3) UV Sterilization Robots – The Latest Infection Prevention Technology in Disinfecting Operating Rooms (Meditek) https://www.meditek.ca/uv-sterilization-robots-infection-prevention-technology-operating-rooms/

(4) About UVC (Klaran) https://www.klaran.com/klaran-university/about-uvc

(5) Ultraviolet radiation (Canada Occupational Health and Safety) https://www.ccohs.ca/oshanswers/phys_agents/ultravioletradiation.html

(6) Office of risk management – UV exposure limits (University of Ottawa, 2020) https://orm.uottawa.ca/my-safety/em-radiation/uv/exposure-limits

(7) Reduce Hospital Acquired Infections with the UV Disinfection Robot (Blue Ocean Robotics) http://www.uvd-robots.com/

(8) IUVA COVID-19 FAQ (International UV association, 2020) http://iuva.org/iuva-covid-19-faq

(9) Ultraviolet germicidal irradiation (Wikipedia) https://en.wikipedia.org/wiki/Ultraviolet_germicidal_irradiation

Last edited by Alf; 13/10/20 1:44 PM.

Darren Magee
Head of Medical Physics & Clinical Engineering
AP(D)
Epsom & St Helier University Hospitals NHS Trust