Ultraviolet light is an important tool in the fight against COVID-19, and is being used to disinfect everything from hospital CT scanners to firefighters’ boots. HVAC systems incorporate UV lights to reduce the spread of the airborne disease in building interiors. UV radiation occurs at wavelengths from 10 to 400 nanometers, and is largely invisible to the human eye. However, it can, at certain wavelengths, cause significant damage to our eyesight, skin, and immune system, undermining its utility as an antiviral in occupied spaces.
Fortunately, a growing body of research, including a new report released on Sept. 30 in the journal Scientific Reports, asserts that light on a narrow range of the visible spectrum has virucidal effects. The recent study was conducted by the Icahn School of Medicine at Mount Sinai in partnership with commercial lighting manufacturer Kenall, and it demonstrated the efficacy of 405 nm visible light in “inactivating” COVID-19 and influenza A in simulated real-world settings, far more safely for humans than UV radiation. Kendall’s Indigo-Clean technology applies 405 nm visible light in overhead lighting.