Ultraviolet lamp

Ultraviolet (UV) lamp


Ultraviolet (UV) light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than x-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV. It is so named because the spectrum consists of electromagnetic waves with frequencies higher than those that humans identify as the color violet.

UV light is found in sunlight and is emitted by electric arcs and specialized lights such as black lights. As an ionizing radiation it can cause chemical reactions, and causes many substances to glow or fluoresce. Most people are aware of the effects of UV through the painful condition of sunburn, but the UV spectrum has many other effects, both beneficial and damaging, on human health.

In terms of impact on the environment and human health (and choosing sunglasses!), it can be useful to subdivide the UV spectrum in a different way, into UV-A ("blacklight" or Long Wave UV with a 380 to 315 nm wavelength), UV-B (Medium Wave at 315 to 280 nm), and UV-C (the "germicidal" or Short Wave UV that ranges from 280 to 10 nm). [1]


  1. Russell, Randy., Windows to the Universe. "Ultraviolet (UV) Radiation". May 17, 2010.