A cable comprising: (a) at least one conductor; (b) an insulating layer which forms a ceramic when exposed to elevated temperatures experienced in a fire, and comprising: (i) a polymer base composition selected from the group consisting of silicone polymer base compositions, non-silicone polymer base compositions and blends of silicone and non-silicone polymer base compositions, wherein, said non-silicone polymer base compositions and said blends of silicone and non-silicone polymer base compositions comprise at least 50% by weight of the total polymer base composition of organic non-silicone polymer; and (ii) a silicate mineral filler; and (c) at least one additional heat transformable layer which forms a ceramic when exposed to elevated temperatures experienced in a fire wherein said at least one additional heat transformable layer comprises: (i) at least 15% by weight of a polymer base composition comprising at least 50% by weight of an organic polymer, based on the total weight of said at least one additional heat transformable layer; (ii) at least 15% by weight of silicate mineral filler based on the total weight of said at least one additional heat transformable layer; and (iii) 20-40 % by weight of ammonium polyphosphate based on the total weight of said at least one additional heat transformable layer. (a) at least one conductor; (b) an insulating layer which forms a ceramic when exposed to elevated temperatures experienced in a fire, and comprising: (i) a polymer base composition selected from the group consisting of silicone polymer base compositions, non-silicone polymer base compositions and blends of silicone and non-silicone polymer base compositions, wherein, said non-silicone polymer base compositions and said blends of silicone and non-silicone polymer base compositions comprise at least 50% by weight of the total polymer base composition of organic non-silicone polymer; and (ii) a silicate mineral filler; and (i) a polymer base composition selected from the group consisting of silicone polymer base compositions, non-silicone polymer base compositions and blends of silicone and non-silicone polymer base compositions, wherein, said non-silicone polymer base compositions and said blends of silicone and non-silicone polymer base compositions comprise at least 50% by weight of the total polymer base composition of organic non-silicone polymer; and (ii) a silicate mineral filler; and (c) at least one additional heat transformable layer which forms a ceramic when exposed to elevated temperatures experienced in a fire wherein said at least one additional heat transformable layer comprises: (i) at least 15% by weight of a polymer base composition comprising at least 50% by weight of an organic polymer, based on the total weight of said at least one additional heat transformable layer; (ii) at least 15% by weight of silicate mineral filler based on the total weight of said at least one additional heat transformable layer; and (iii) 20-40 % by weight of ammonium polyphosphate based on the total weight of said at least one additional heat transformable layer. (i) at least 15% by weight of a polymer base composition comprising at least 50% by weight of an organic polymer, based on the total weight of said at least one additional heat transformable layer; (ii) at least 15% by weight of silicate mineral filler based on the total weight of said at least one additional heat transformable layer; and (iii) 20-40 % by weight of ammonium polyphosphate based on the total weight of said at least one additional heat transformable layer.