Cosmetic products. Measurement of the efficacy of sun protection products by diffuse reflectance spectroscopy

This specification establishes a standardized methodology for assessing the efficacy of sun protection products through the analysis of diffuse reflection spectra. It defines precise procedures for measuring how skin simulators interact with ultraviolet and visible light after application of cosmetic formulations designed to shield against solar radiation. The document outlines the required instrumentation, calibration protocols, and data processing techniques necessary to ensure consistent and reproducible results across different testing environments. By employing non-contact optical measurements, this approach minimizes variability associated with physical application techniques or human subject variability. It provides a framework for manufacturers, regulators, and independent laboratories to evaluate the protective performance of creams, lotions, and sprays under controlled conditions. The methodology focuses on quantifying the reduction of light transmission and reflection to derive protective factors that indicate the level of defense offered by the product. Adherence to these guidelines facilitates international harmonization in testing protocols and supports the reliability of product labeling claims regarding sun protection capabilities.