scope:

This test method provides an in vitro procedure to characterize the UVA protection of sunscreen products. Specifications are given to enable determination of the spectral absorbance characteristics of UVA protection in a reproducible manner. In order to determine relevant UVA protection parameters the method has been created to provide a UV spectral absorbance curve from which a number of calculations and evaluations can be undertaken. Results of this measurement procedure can be used for other computations as necessary for local regulatory authorities. These include calculation of Ultraviolet-A Protection Factor (UVA-PF) (correlating with in vivo UVA-PF from Persistent Pigment Darkening testing procedure), Critical Wavelength, and UVA/UVB absorbance proportionality. These computations are optional and relate to local sunscreen product labelling requirements.