A flame retardant thermoplastic molding composition containing a thermoplastic copolymer A, a graft copolymer B, and a flame retardant component C, wherein the molding composition contains: A: from 40 to 80% by weight of a thermoplastic copolymer A, obtainable e.g. from acrylonitrile and styrene; B: from 15 to 50% by weight of a graft ABS copolymer B, and C: from 15 to 30% by weight of the flame retardant component C, comprising at least an expandable graphite component (C1) and a phosphorous flame retardant component (C2) and a perfluorinated polymer (C3); has a high fire protection and improved mechanical properties.