Distilling Disinfecting Lighting Resources and Best Practices
Lauren Schwade, LC, EDAC, IES
Senior Associate, Senior Lighting Designer
We’ve all been inundated with methods/resources on best cleaning and disinfecting practices that the healthcare industry can start utilizing TODAY. From appropriate cleaning products and procedures to types of filters and face masks that can be utilized, we’ve heard (and read) about it all… but, what about using light as a disinfection tool? Several companies in the market are claiming such products–lights with disinfecting capabilities. We’ve attempted to distill tips and guidelines–how to assess practices and products and how to apply it with today’s needs in response to COVID-19.
Ultraviolet light has germicidal properties at its core, but different wavelengths of light are used for different purposes. A few architectural lighting companies are currently offering safe germicidal wavelengths of light (in their architectural lighting products) in the near UV range, still in the visible spectrum. Those products range from ceiling troffers to downlights; they typically have an “always on” safe mode along with a higher intensity mode that should be saved for after-hours use only when rooms are unoccupied. The longer a light is left on, at a higher intensity, the greater the kill rate and decontamination of the room. NOTE: These architectural products were designed to add an additional level of disinfection in your healthcare environment (another tool in the kit) and not to replace existing cleaning protocols. Keep in mind, a ceiling mounted light may only disinfect surfaces below it, not under or around it. The surface material itself impacts the effectiveness of the disinfecting lights as well — if the material is more porous, has a coating or is soiled etc., it will influence how the light “cleans” the surface.
COVID-19 and other viruses like SARS and MERS are not as easy to kill, requiring a stronger, shorter wavelength of light, known as UV-C. This range of ultraviolet light is able to change the structure of DNA/RNA molecules deactivating viruses. This source of UV-C light, in the past, has only been made possible by using Mercury or Xenon light sources in primarily large and expensive pieces of medical equipment. This equipment is then moved around the room for disinfecting purposes, which can be a significant hassle for facilities. LEDs are giving our healthcare industry an advantage and creating new pathways to emit calculated wavelengths of light with computer chips, producing light for different causes. We are living in a time where lighting is not just used as a room lighting tool anymore, but instead, can be fine-tuned and prescribed at certain dosages. Architectural lighting manufacturers are still learning, researching, and growing. Wavelengths in the FAR-UV-C range are being studied to combine both strategies – prescribed healing and virus deactivation under safe white light. Only time will tell where this brings our industry and our world.
The following is our distilled list of resources intended to help guide your thinking on the most appropriate disinfecting light for your facility. We are happy to discuss further with you.
Architectural Lighting Products (vs. medical equipment)