Sun Protection Factors: Regulatory Issues and Methods of Determination

Abstract

AbstractClinical procedures to quantify sunscreen efficacy have been formally developed by government or private standards organizations in the United States, Germany, and Australia. The background of these standards is reviewed. Their chief provisions, including major areas of difference, are described. The radiation source employed is one of the major differences in these methods, and a review of studies evaluating the attributes of natural and artificial radiation sources is provided. Nonclinical test methods are discussed: in vivo methods include erythemal and DNA synthesis evaluations; in vitro methods involve spectrophotometric analyses and include the dilute-solution, thin-film, and mouse epidermis methods.