Sunscreen use began in the early 20th century. Salicylates were the first agents used in sunscreen preparations, with the first reported sunscreen containing benzyl salicylate and benzyl cinnamate (34). In the 1940s, p-Aminobenzoic acid (PABA) was patented and incorporated into sunscreen formulations (35). Since its debut, various formulations and derivates of PABA have been introduced into the sunscreen market. Today, the FDA approves the use of 16 chemicals as defined sunscreen agents (Table 1).
Since no single agent effectively provides adequate protection from both UVA and UVB radiation, nearly all commercially available sunscreen products contain agents from both groups. Two or more sunscreen active ingredients may be combined with each other in a single product when used in the concentrations approved by the FDA for each agent. Each individual active ingredient must contribute a minimum SPF of at least 2 to the finished product, with the finished product having a minimum SPF of not less than the number of sunscreen active ingredients used in the combination multiplied by two. Sunscreen agents are classified based on their method of protection. Chemical sunscreens
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Table 1 FDA-Approved Active Ingredients for Sunscreens
Source’. From Ref. 36. |
absorb UV radiation while physical blockers act as particulate matters that reflect and scatter incident light.