The invention relates to blends containing polymers of vinylidene fluoride, having low ductile-brittle transition temperatures and having excellent low temperature impact properties while maintaining the positive aspects of unmodified vinylidene fluoride-containing polymers. The blends of this invention are produced by adding a core-shell impact modifier (CSIM) comprised of a polysiloxane core and a shell compatible with vinylidene fluoride-containing polymer. The blends are further characterized by the presence of a heterogeneous copolymer composition comprised of two or more distinct phases and/or at least one flame and smoke suppressant. The preparation of these new blends can be done by conventional thermoplastic compounding techniques such as twin screw compounding; alternatively, the CSIM can be introduced earlier, such as in the latex. The unique properties of the new blends make them useful in end-use applications where those properties provide performance advantages, such as in wires & cables and in oil and gas applications.