Organic materials which possess outstanding stability to oxidative, thermal or light-induced degradation comprise as stabilizers at least one compound of the benzofuran-2-one type and at least one compound of the sterically hindered amine type. An organic phosphite or phosphonite may also be included in the stabilizer mixture. The organic material may be a polymer e.g. a polyolefin, for instance phenol - free polyolefin fibre.
