What is ultraviolet radiation?

Ultraviolet radiation refers to a specific segment of the electromagnetic spectrum defined by its wavelength. It encompasses wavelengths ranging from approximately 100 nanometers (nm) to 400 nm. This range places ultraviolet (UV) radiation just beyond the visible light spectrum, which begins at about 400 nm and extends to approximately 700 nm.

The classification of UV radiation includes several subtypes: UVA, UVB, and UVC, each differing in their respective wavelengths and biological effects. While ultraviolet radiation can significantly impact human health—such as contributing to skin cancer and other conditions—the defining feature of ultraviolet radiation is its wavelength. The choice indicating wavelengths between 100 nm and 400 nm accurately encapsulates this aspect of UV radiation.