UV or no UV? Do LEDs emit UV rays

30 October 2019 by

Debates are on about whether or not LED lights to emit UV rays or not. Discussions are going on about the possible side effects of LED lighting and if they are harmful to the health of people. The other problem that is being most talked about is whether the LEDs are good at preserving artworks, artifacts, and the decor from aging.

A look into the making of LED lights

The major fact is that LEDs are not capable of emitting white light by themselves. Scientists were successful in inventing LEDs in the primary colors, red, blue and green and the varying hues of these colors. But white light still seemed to be mysteriously evasive. Then came the brilliant blue LEDs. This led to the discovery o white light LEDs.

Phosphor along with a rare earth compound, when coated on the brilliant blue LED, emits another color of a wavelength that is perceived by the naked eye as white light. Thus entered the white light LED into the market and we buy them with ease.

The phosphor mix emits light that is broadband in nature. Even though fluorescent lights also use the phosphor mix, the broadband is much wider when used with LED. The thickness of the phosphor coating and the yellow in it determines how much brilliant blue LED is absorbed by the phosphor. Ultimately this gives the LED different CRI and Kelvin temperatures.

The Kelvin temperature is lower and the color is yellower as the phosphor absorbs bluer. This, in turn, affects the efficacy of LEDs. The lower the temperature, the more actual LED light is absorbed by the phosphor, and it takes more power to get the same light.

So what is the final word?

The brilliant blue LEDs that make the white light LEDs do generate UV rays in the range 400-425 nm. But the amount emitted by phosphor is lower than generated. Statistically, the ultimate amount of UV emitted is reasonably less.

Again the UV emitted is far less making them the favorites of museums that are searching for new options or preserving artifacts and maintain it with all originality and without the colors fading away. But with clean rooms having sensitive films that can be affected by wavelengths less than 415 nm, you should better avoid using unfiltered LED lights. Concluding, LEDs emit very few UV rays.