NOVELTY - Mixture of substances comprises a salt of metal cations and thermally activatable reducing anions, and at least one polyol, where the thermally activated reducing anions are anions, during reaction at a temperature between 100-450 degrees C, having a normal potential value of less than 0 V with a sufficient reaction rate at 25 degrees C relative to the standard hydrogen electrode, the reaction rate of the reaction of the thermally activatable anion is at least 10 mol.% for a period of one hour, and the anion is an organic molecule having at least two hydroxy groups per molecule in the polyol to be used.    USE - The mixture of substances is useful for preventing thermo-oxidative degradation and/or photo-oxidative degradation of thermoplastic molding compounds, or for producing fibers, films or molded articles that are useful for the manufacture of articles for the electrical-, electronic-, telecommunications-, information technology, solar, computer industry, for domestic use, for the sport, for the medical application or for the entertainment industry, preferably for motor vehicles and an engine compartment of motor vehicles (all claimed), where the mixture of substances is useful as a stabilizer system for the molding compounds.    ADVANTAGE - The mixture of substances prevents the degradation of compounds in an efficient manner. The fibers, films or molded articles can be economically manufactured with improved strength and service life and without any damage.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) thermoplastic molding compounds, comprising the mixture of substances;    (2) producing the thermoplastic molding compounds, comprising blending, mixing, kneading, compounding, extrusion or rolling (i) 10-99.75 wt.% of thermoplastic polymer(s), (ii) 0.05-10 wt.% of the salts of metal cations and the thermally activatable reducing anions, (iii) 0.1-10 wt.% of the polyols, and (iv) 0.1-70 wt.% of other ingredients, at a temperature of 220-400 degrees C;    (3) fibers, films or molded articles obtained by injection molding, extrusion, or blow molding of the thermoplastic molding compounds; and    (4) reducing photo-oxidative and/or thermo-oxidative damage of thermoplastic molding compounds containing the thermoplastic polymer, or films, fibers or molded articles to be produced, comprising adding the mixture of substances to the thermoplastic polymer.