the present invention relates to fire resistant sustainable sandwich panels comprising a thermoplastic foam core in between outer skins made of natural fibres set within a natural thermoset biopolymer . the sandwich panels are provided with a fire resistant protective coating on an outer surface . this surface may be the surface facing the cabin when installed in an aircraft interior . such fire resistant sustainable panels provide the required flame and heat resistance , have a high strength - to - weight ratio , low maintenance costs and are generally easily installed . furthermore , the fire resistant sustainable sandwich panels allow easy recycling and are cheaper than conventional sandwich panels .