Flame-retardants (FRs) are incorporated into polymers to reduce the fire hazards. FRs can modify the decomposition pathway of polymers to yield char and/or to change the evolving gaseous products [1]. The aim of this paper is to show how to characterize decomposing FR polymers using advanced characterizations namely, solid state NMR (2D NMR and dynamic nuclear polarization-enhanced (DNP) NMR) and conceptualization (fractal approach).