FTIR and GCMS analysis of epoxy resin decomposition products feeding the flame during UL 94 standard flammability test. Application to the understanding of the blowing-out effect in epoxy/polyhedral silsesquioxane formulations

•A validated method to collect and analyze the fuel released during flammability test.•This method is useful to study flame retardancy mechanism in real flaming conditions.•Blowing-out mechanism in flame retarded epoxy resin was elucidated by this method.•DOPO-POSS in epoxy significantly changes composition of fuel mix feeding the flame.•Lower flammability of blown-out fuel explained by the high phenol/hydrocarbon ratio.