From my comment to al-Ghaili post
https://www.facebook.com/ScienceNaturePage/videos/223929302517497/?app=fbl
The flaw is that the UV must be UV-C light about 265 to 285 nm wavelength. This wavelength is not emitted by almost all UV LEDs. The plastic lenses in cheap LEDs do not allow UV-C to pass through. The LED window must be glass that passes UV-C. Did you notice that they showed the disinfecting lights and they were all glass tubes?? If you want to find out if your UV LED puts out UV-C, do the green banana test. Search for green banana uv test on YouTube. Big Clive has a video on how it’s done. If your UV light uses LEDs it is very doubtful that it will put out UV-C. Don’t be fooled by false advertising for LED lights that will sterilize! They don’t!