The sun produces a great quantitiy of energy, which is transmitted by radiation of various types (see sidebar). When sun rays reach human skin, they interact with the epidermal cells. They are also able to interact with sun filters, which are substances applied on the skin to prevent sunburn and erythema. UV radiation, in particular, produces a high activation energy and induces a partial degradation or alteration process in a filter so that the filter reduces or loses its capacity for skin protection.1 This process is called photodegradation.
Excerpt Only This is a shortened version or summary of the article that appeared in the Sep. 1, 2001 issue of Cosmetics & Toiletries magazine. The full content is not currently available online.