But what is UV? Ultraviolet is named so because on that is the color that is perceived by a packet of light traveling at a certain frequency of wavelength. Compared to the other visible colors, they are extremely tiny and short wavelengths.
Because of their shorter wavelengths, they carry more energy than the other colors. And it is this energy, packed so tightly, which is so disruptive to biological molecules which more or less erode and deform over time as they are bombarded.
While general lighting technologies have never emitted ultraviolet light to the point of causing health hazards, relative to LEDs, it is substantially greater. Take a look at the composition of light from different light sources from a study done by Lighting Europe in 2011:
Notice how all the LEDs charted have their light composition drop off immediately where UV range begins, but the incandescent lamp even has part of its light spectrum in the deep UV range. It would be dangerous if it was as strong as sunlight which is charted as daylight in the graph. But even this amount of UV from incandescent can be disturbing to those which have photophobia which is a medical condition for those extremely sensitive to light. And over time, it can degrade photo-sensitive materials as well as shorten the shelf-life of foods (beer anyone?)
So it’s an important reminder that aside from the huge energy savings LEDs bring, they also help eliminate real problems from legacy illumination which can now be dealt with.