What are the different sun rays?
The sun emits three kinds of non-visible ultraviolet light: UVA, UVB and UVC. UVC is the shortest, most harmful light but is primarily stopped by the earth’s ozone layer. UVB is the medium wavelength of light and is necessary to trigger the tanning process, but too much UVB can cause sunburn. UVA is the longest wavelength and is responsible for the oxidization of melanin in the skin. The Tanning Process What is the tanning process? UVB stimulates the melanocyte cells in the skin to produce melanin ( a.k.a. pigment) which is then oxidized by UVA, turning it brown. As the outer layer of skin sheds, cells are lost and your tan will fade. Therefore, to maintain a tan requires continuous exposure to ultraviolet light. The degree of colouring depends on the amount of melanin you have, your individual reaction to ultraviolet light and the time of exposure.
