The ozone layer in the stratosphere shields the Earth from penetration of UV radiation (UV-A, 315-400 nm; UV-B, 280-315 nm; UV-C, 100-280 nm) and thus prevents from the harmful effects of UV radiation on cellular damaging. However, the ozone layer is continuously depleting because of the increasing use of anthropogenically released environmental hazards such as chlorofluorocarbons, chlorocarbons and organobromides. This can lead to an increase in UV-A and UV-B exposure on the Earth. UV-A is the most commonly penetrating type of UV light, while UV-B’s penetration is increasing due to the reduction of ozone layers. UV-C usually cannot reach the Earth’s surface as it is absorbed completely in the atmosphere. Of the types of UV radiations, UV-B is the most detrimental because it has enough energy to cause photochemical damage to cellular nucleic acids and proteins. Microalgae have the inherent capacity to produce various UV-screening and various antioxidant compounds as well as detoxification and anti-oxidative enzymes to survive the stressful environments. Shannon ABC are currently collaborating with an Irish cosmetics company, TanOrganic, to commercialise naturally produced sunscreen compounds.