ISO 21348 中按波长对各种紫外线进行的定义：
Ultraviolet (UV) irradiances are defined as the wavelength range of (100 u λ < 400) nm.
Ultraviolet C (UVC) irradiances are defined as the wavelength range of (100 =/< λ < 280) nm.
Ultraviolet B (UVB) irradiances are defined as the wavelength range of (280 u λ < 315) nm.
Ultraviolet A (UVA) irradiances are defined as the wavelength range of (315 u λ < 400) nm.
Vacuum Ultraviolet (VUV) irradiances are defined as the wavelength range of (10 =/< λ < 200) nm.
Extreme Ultraviolet (EUV) irradiances are defined as the wavelength range of (10 =/< λ < 121) nm.
Lyman-alpha (Lyman-α) irradiances are defined as the wavelength range of (121 =/< λ < 122) nm.
Far Ultraviolet (FUV) irradiances are defined as the wavelength range of (122 =/< λ < 200) nm.
Middle Ultraviolet (MUV) irradiances are defined as the wavelength range of (200 u λ < 300) nm.
Near Ultraviolet (NUV) irradiances are defined as the wavelength range of (300 u λ < 400) nm.