The present disclosure relates to a cosmetic agent for lightening keratin fibers, which contains two separate powder-formed preparations (A) and (B), each of which is packaged as a water-soluble film, and a method for lightening keratin fibers using the agent. The first preparation (A) comprises potassium peroxydisulphate, ammonium peroxydisulphate, a hydrated sodium silicate and magnesium carbonate. The second preparation comprises at least one of a percarbamide, a percarbonate and a perborate. The cosmetic agent of the present disclosure does not require the use of (free) hydrogen peroxide solution. This minimises irritation to the user. This also ensures that no overdosing of hydrogen peroxide occurs and that there is less waste peroxide to be disposed of.
