Foundations and self-tanning products: Do they provide any protection from the sun?

As soon as the weather turns sunny, everyone wants a tan. People with skin phototypes III and IV, called melanocompetent, have no problem meeting this fashion requirement. But things are quite different for people with phototypes I and II and so these individuals look for alternative solutions. In essence, light skin burns easily when exposed to the sun. Therefore, light-skinned people are offered a cosmetic solution through self-tanning products or foundations. It seemed interesting to us to evaluate the sun protection power of this type of product. To do this, we used an in vitro method to determine the typical indicators related to sunscreen products, such as sun protection factor (SPF), ultraviolet (UV)-A protection factor (PF-UVA), UV-B/UV-A ratio as well as the critical wavelength because these artificial tanning products could be considered sunscreen products by users. It is important to know whether a self-tanning product and/or a foundation provide sun protection and whether they meet the standards set for other sunscreen products. Protection which is imbalanced for either UV-B or UV-A radiation is potentially harmful for users believing themselves adequately protected. To do this, we assembled the requisite conditions for forming melanoidins in the cosmetic itself. We tested seven amino acids found in the corneal cells of the epidermis. Regardless of the amino acid used, the corresponding SPF was essentially zero (approximately SPF 2). Foundations, on the other hand, proved to be much more interesting because they possess a non-negligible SPF as well as good photostability making these products safe in terms of their mode of application (applied once daily).