The risk reactor site you just posted is very good. 365 nm is reasonably safe and won’t hurt you if use lower power and limit your exposure. 380–400 nm is the lower limit of human vision.
Note there are shorter wavelengths but they are not safe to use. Unless you are wearing protection, you will damage your eyes so stick with 365nm.
Don’t believe everything you see on TV. The real inspection units are shuttered and have glasses that are synchronized with the light source but at 180 degrees out of phase – closed when the light is on, open when the light is off. I won’t get into details but some fluids will glow for a short period of time (milliseconds) after being exposed to a very bright flash source of a certain wavelength. Imagine you have a bright strobe that flashes at 30 times per second and wear glasses that are synched with the flash. They close when the flash takes place and open the instant the bright flash turns off. The wearer is not blinded by the light but can see the instantaneous dim glow of the target fluid. Cool huh?
They can’t show that on TV because 1) it is too expensive, 2) the TV is strobed and you’d get nonsense. Instead, they do the easy thing and mix some UV dye into the juice so viewers see the glow and are wowed by the technology. Showmanship. It’s a bit like when they show bullets sparking when they hit metal objects. It’s nonsense but it looks neat. Actually some special effects person either put those flashes there during post processing or, in the early days, planted small charges that were detonated electrically.
Viewers don’t know the difference – or don’t care.
It’s all Physics. That is where the world’s real magic lies.