Building polymers are highly flammable and produce a vast amount of toxic chemical compounds in the event of a fire which can lead to potential incapacitation and death. To gain an in-depth understanding of this issue, smoke toxicity and thermal characteristics of seven commonly used building polymers were analysed through a systematic fire performance evaluation system using a Thermogravimetric Analyzer and a Cone Calorimeter coupled with an FTIR arrangement. Four Fractional Effective Dose (FED) expressions were compared to assess the smoke toxicity of the fire effluents based on different assumptions. It was found that FED_N2, calculated using Purser’s equation, reported the highest values of FED with the following order of potential smoke toxicity at 50 kW/m² radiative heat flux: LDPU > HDPU > PE > HDEPS > XPS > EVA > LDEPS. Furthermore, fire performance evaluation of the polymers was carried out by considering three key fire risk parameters, i.e., flashover propensity, total heat released, and toxic hazard. At 50 kW/m² radiative heat flux, HDPU exhibited 11.7 times flashover propensity compared to the least flammable polymer (HDEPS), EVA exhibited 5 times total heat release compared to the polymer with the lowest total heat release (LDEPS) and, LDPU exhibited 6.7 potential times toxic hazard compared to the least toxic polymer (EVA).

Polyurethane (PU) foam has a high flammability and is widely used in aircraft interiors, presenting a significant danger to occupants. This study analysed three composite intumescent flame-retardant (IFR) coatings for flexible PU foam; expandable graphite (EG), ammonium polyphosphate (APP) and alginate (AG). The coatings were prepared in concentrations of 5 wt%, 10 wt%, and 50 wt% with an acrylic binder. The coated samples were characterised using cone calorimetry, SEM, and mechanical testing. The findings showed peak heat release rate, total heat release, and carbon dioxide production from the 10 wt% triple-layer coating (EG:APP:AG) was 52%, 32%, and 58% less than the PU control. The char of the 10 wt% triple-layer sample effectively suppressed smoke release and inhibited the transfer of fuel and gas volatiles. Mechanical testing demonstrated a 3.4 times increase in tensile strength and a 15.4 times increase in compressive strength (50% compression) compared to the control PU with the 10 wt% triple-layer coating. A fire dynamics simulator model was developed that demonstrated large-scale flammability modelling for commercial aircraft. Future work can explore the integration of IFR coatings into computational analysis. These new bio-based coatings produced promising results for aircraft fire safety and flammability performance for PU polymers.