At ESFSS (above), two studies underway with BASF analysed different flame retardants in PBT polymer. Nils Roenner, Imperial College London, showed in PBT the physical material fire behaviour impacts of 20 µm hollow glass nanospheres (which insulate and slow heat transfer into the polymer) and 50 µm boron nitride platelets (which accelerate heat transfer), and resulting changes in fire test results. Isaac Leventon, NIST USA, compared in glass fibre reinforced PBT the fire behaviour of polybrominated (+antimony) vs. phosphorus-based (+melamine) flame retardant systems. Both FR systems achieved self-extinguishing in a UL94 type set-up. In the brominated system, the flame remained regular, but self extinguished by “lift-off” from the polymer surface (gas phase FR action). In the phosphorus system, initial ignition was not retarded, but the flame before self-extinguishing was irregular (burning only through cracks in the char development) and had lower heat. Elani Asimakopoulou, FireSERT Belfast Northern Ireland, presented testing of inorganic “smart” FRs (magnesium – aluminium layered double hydroxides, and ZrP (zirconium phosphate) in polyisocyanurate (PIR) foam insulation materials.