radiation as heat. This means that less than 0.1% of the excited melanin molecules will undergo harmful chemical reactions or produce free radicals. Artificial melanin The cosmetic industry claims that the UV filter acts as an "artificial melanin". But those artificial substances used in sunscreens do not efficiently dissipate the energy of the UV photon as heat. Instead these substances have a very long excited state lifetime. In fact, the substances used in sunscreens are often used as photosensitizers in chemical reactions. (see Benzophenone). Oxybenzone, titanium oxide and octyl methoxycinnamate are photoprotective agents used in many sunscreens, providing broad-spectrum UV coverage, including UVB and short-wave UVA rays. See also Sunscreen Photocarcinogen Direct DNA damage Indirect DNA damage References Biological defense mechanisms Photochemistry Skin physiology Sun tanning