AU222 Safety

The UVA and UVB regions do not exhibit particularly strong germicidal effects. In contrast, the UVC region demonstrates exceptionally high disinfecting capability, making it a promising field for light‑based sterilization technologies. Among UVC wavelengths, light at 222 nm has drawn significant scientific and medical attention, as numerous recent studies have shown that it combines strong germicidal performance with minimal impact on human health. The key factor is absorption: while UVA and UVB penetrate deeply into the skin (with tanning being a defensive response), 222 nm UVC light is absorbed entirely within the outermost layers, preventing deeper penetration. Although ultraviolet exposure to humans is broadly regulated worldwide, many Western countries have introduced special exemptions for this specific wavelength, allowing its active use in public‑health applications. Since the onset of the COVID‑19 pandemic in 2019, its adoption has accelerated considerably.