[byb]

Personally I feel the use of the term "far uv" is very misleading because the 220 nm wavelength is within UVC, and not too far away from 254 nm germicidal UVC. It is always helpful to consult a chart:

http://www.drb-mattech.co.uk/uv%20spectrum.html

So, from a public health/public education standpoint, I find it troubling that scientific research, which the article points out, is limited in this area. For decades, general advice has been that all UVC is dangerous to all life. We don't know below which wavelength does UVC no longer become harmful to animal (human) cells. Nor do we know if 220 nm wavelength light damage/weaken other materials. I'm not a chemist/engineer so I don't know if theoretical calculations can be made or if a massive scientific effort needs to be done to verify the impact of 220 nm UV light on lots of materials/life.

If there is an animal/human cell safety region, perhaps a rebranding or subdivision of UVC into a "UV-D" is better than calling this "far uv". This has the added benefit of the "D" meaning "Death to germs/viruses".

YouTuber Big Clive has had several videos on UVC lamps, I'd like to see someone get a 220 nm light into his hands to see if he smells like burnt meat. https://youtube.com/watch?v=1m0TQjBRcFo https://youtu.be/6DlfLthx89E?si=V4FD0DO4l09w2Wlr

Edit: maybe I am a bit alarmist, some comments did share additional information about products offering this technology... I still hold that the branding/messaging is a problem by lumping it all together

[bsder]

As I understand it, the point of 222nm is NOT to sterilize organic tissue directly.

The point of 222nm is to able to use it for sterilization in things like air return ducts, industrial cleaning equipment, etc.

Since 222nm is relatively "safe", you don't have to worry some idiot opening up a system, giving himself a gigantic flux of UV in the face, and winding up in the ER for cornea burns.

Consequently, your maintenance people don't need special equipment or extra training.

[byb]

This is the point of mechanical/electrical interlocks to prevent exposure to energized UVC. This is why I find the attempt to make 'far uv' safe in the public conscious even more dangerous.