According to the news in April this year, a joint study by Kobe University in Japan and the Japanese LED component manufacturer Ushio showed that repeated irradiation of hairless mice with particularly sensitive skin with filtered 222 nm UVC light would not cause skin cancer or cataract. It shows that deep ultraviolet radiation with wavelength of 222nm is harmless to human skin and eyes.

Similarly, Columbia University in the United States has also conducted related research. The preliminary results show that far UVC with a wavelength of 222nm cannot penetrate the skin surface or eyes, is safe for human body and can kill viruses.

It is reported that the research team of Oxtail and Department of Plastic Surgery of Kobe University has completed a study, which shows that irradiating filtered 222nm UVC light on human skin can reduce the number of bacteria on human skin without causing damage to the skin.

This study used oxtail care 222? UV-C disinfection equipment with wavelength of 222m and radiation energy of 500 mJ/ cm2 includes an optical filter. This short band-pass filter is based on the research and technology of Columbia University, and has been patented, which can filter radiation with wavelength above 230nm.

However, the unfiltered 222 nm UV-C lamp will pose a serious threat to human health if it is not properly filtered. At present, all the 222 nm external lights on the market are not mono-spectral. "222 nm" only refers to the peak wavelength, but also emits other wavelengths, many of which are harmful. Without filtering, even the 222nm ultraviolet lamp is dangerous, because it will produce light as high as 320 nm! It should be clear that the "safe zone" of UV-C is between 200 nm and 230 nm. At present, there are still many disputes in the industry about whether UVC light can kill coronavirus and whether UVC light with wavelength of 222nm is harmless to human body. People from all walks of life are very concerned about this and expect more detailed research to prove these results.