Ultraviolet (UV) radiation is the part of the invisible radiation spectrum created by the sun. UV radiation is made up of elementary particles known as photons, which are categorised into wavelengths. The wavelength varies inversely in accordance to its energy – the shorter the wavelength, the greater its energy. The skin reflects some UV radiation naturally, but care must be taken since that which penetrates the skin tends to damage the cells permanently.
There are three types of UV rays: UVA, UVB and UVC. The UV radiation wavelength range is 100-400nm, often referred to as the Broad Spectrum. These levels are not constant and are subject to change from seasons, atmosphere and even the time of day.