What is Ultraviolet Light (UV)?

Ultraviolet light is invisible to the human eye. It is part of the electromagnetic spectrum that lies beyond the purple range of the visible spectrum. The ultraviolet (or UV) spectrum has wavelengths between 100 and 400 nanometers (nm). The UV spectrum is further divided into wavelength ranges named UVA, UVB, UVC:

• UVA: sun tanning, testing, inspection, insect traps, stage effects, blacklight, phototherapy* (315-400nm)
• UVB: sun burning, inspection, analysis, testing, phototherapy* (280-360nm)
• UVC: germicidal (253.7nm), ozone producing (185nm)

*Phototherapy for treatment of skin diseases uses bulbs emitting in the UVA and UVB spectral range. There is also non-UV phototherapy for treatment of infant jaundice. These bulbs, "bili lights", are low or non-UV emitting fluorescent or halogen sources with strong blue light in the visible spectral range of 425-475nm.

Warning: UV radiation is harmful to skin and eyes.