Séhédic, D., Hardy-Boismartel, A., Couteau, C. et al. Arch Dermatol Res (2009) 301: 603. doi:10.1007/s00403-009-0974-2
The goal of this study is to investigate commercially available cosmetics (foundations, skin care creams) which also claim to include a sun protection factor (SPF). Are these products, which are not considered sunscreen products, helpful or could they be harmful? Using an in vitro method, we tested the effectiveness of 35 commercially available products against UVB and UVA radiation. For each product, our testing focused on determining the following four values in terms of current legal recommendations: SPF, UVA protection factor (PF-UVA), UVB/UVA ratio and critical wavelength (λc). We also tested each product’s level of photostability. Effectively, when considering instructions for use (skincare products are applied once, in the morning) any product displaying an SPF must be particularly photostable, since its labeling does not indicate reapplication. In contrast, the packaging on sunscreen products clearly indicates the necessity of frequent reapplication. Out of the 35 products we tested, seven do not comply with legislation regarding sunscreen products. This non-compliance translates into insufficient protection against UVA radiation. The products sold in pharmacies did comply. In terms of photostability, only eight products out of the original 35 proved to be sufficiently photostable. It would seem inappropriate to use filters in the formulas of non-sunscreen cosmetics.
SPFFoundationSkin care creamEffectivenessPhotostabilityAppropriateness