This European Standard specifies a HPLC/UV method for the identification and quantification 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 gives HPLC/UV methods for the identification of 38 corticosteroids that may be found in skin whitening cosmetic products (see Annex D). This standard is not dedicated to artificial nail products or soaps.