This European Standard specifies a HPLC/UV method for the assay of hydroquinone, 3 ethers of hydroquinone and 4 corticosteroids most frequently found in illegally sold skin whitening cosmetic products: clobetasol propionate, betamethasone dipropionate, fluocinonide and fluocinolone acetonide. This standard also proposes HPLC/UV methods for the identification of 38 corticosteroids may be found in skin whitening products. Indeed, as corticosteroids could be deliberately introduced in skin whitening cosmetics, despite the fact that they are forbidden to use, an identification of the presence of one of this illicit compounds could be enough for a market survey control. This standard is not dedicated to artificial nail products or soaps.