Sayre R M, Powell J, Rheins L A
Rapid Precision Testing Laboratories, Cordova.
Photodermatol Photoimmunol Photomed. 1991 Oct;8(5):222-4.
A number of factors may alter the efficacy of a sunscreen product being tested. Notably among these are (1) the source of ultraviolet (UV) radiation, (2) the filtration of the UV radiation source, (3) such environmental factors as swimming or sweating (4) and/or the amount of product applied. This is the first report in which the technique of product application itself is examined. We find that the act of rubbing the product into the skin appears also to remove product from the skin. In our study, different techniques of product application produced a 25% deviation in product sun protection factor. The variables associated with the application of sunscreening products are discussed.
许多因素可能会改变正在测试的防晒产品的功效。其中尤其包括：（1）紫外线（UV）辐射源；（2）紫外线辐射源的过滤情况；（3）游泳或出汗等环境因素；（4）和/或所涂抹产品的量。这是首篇对产品涂抹技术本身进行研究的报告。我们发现，将产品揉搓进皮肤的行为似乎也会使产品从皮肤上脱落。在我们的研究中，不同的产品涂抹技术导致产品防晒系数出现了25%的偏差。文中讨论了与防晒产品涂抹相关的变量。
