COVID-19 and Germicidal UV Light: Myth vs. Fact

The Illuminating Engineering Society (IES) has released the white paper “Germicidal Ultraviolet (GUV)–Frequently Asked Questions.” The report is aimed at healthcare applications, addressing the fundamentals of GUV light, its effectiveness, its safety, and more in the age of the COVID-19 pandemic.

According to Brian Liebek, IES director of standards and research, “The goal is to provide timely and objective information on a proven technology that can reduce the spread of this highly contagious virus.”

Germicidal ultraviolet (GUV) refers to short-wave UV-C “light” (it is not in our visible spectrum) in the 200 to 280 nanometers (nm) range that can kill bacteria, mold, and fungi and can inactivate viruses—including COVID-19. According to the report, “Individual, energetic UV-C photons photochemically interact with the RNA and DNA molecules in a virus or bacterium to render these microbes non-infectious.”

There are a lot of misconceptions regarding GUV and COVID-19, so the whitepaper provides questions and answers for a wide variety of topics, including:

• the basics of GUV, such as comparing UV-C to UV-A and UV-B;
• medical and healthcare implications for use of GUV against COVID-19;
• GUV and disinfecting room air;
• GUV and disinfecting surfaces, masks, and instruments;
• safety of GUV;
• lamp technologies; and
• applications and effectiveness.

GUV lighting is not new. It looks similar to fluorescent tubes and has long been used inside HVAC air handlers, where it helps decontaminate coil surfaces or the airstream. But GUV lights are often made with argon and mercury vapor, and require special precautions for installation and use as they can be potentially dangerous to eyes and skin. This report focuses on the safe, effective use of GUV in healthcare applications. Residential UV disinfecting wands and similar products are not covered since they are unregulated, may pose a safety hazard, and are less likely to be effective, according to the report.

David Sliney, Ph.D., chair of the IES photobiology committee, said, “The guidance included in this report should help medical professionals and consumers better understand germicidal UV products, and provides considerations for selecting and employing such technologies.”

For more information:

Illuminating Engineering Society
ies.org