A flame retardant thermoplastic composition comprising a poly(arylene ether), a block copolymer, a liquid polyolefin, and a flame retardant additive composition. The flame retardant additive composition comprises a metal hydroxide, an organic phosphate, and a phosphoric acid salt selected from the group consisting of melamine phosphate, melamine pyrophosphate, melamine orthophosphate, melem polyphosphate, melam polyphosphate, diammonium phosphate, monoammonium phosphate, phosphoric acid amide, melamine polyphosphate, ammonium polyphosphate, polyphosphoric acid amide, and combinations of two or more of the foregoing. The block copolymer comprises a block that is a controlled distribution copolymer having terminal regions that are rich in alkylene units and a center region that is rich in aryl alkylene units. The flame retardant composition may be used in the production of covered conductors.