The thermolysis products in air of two new epoxide based halogen-free flame retardant thermosetting plastics and polycarbonate, a commonly used thermoplastic with some structural similarity to the thermosets, are reported. The thermolysis was carried out in a VCI combustion apparatus at 400, 600 and 800 degreesC and an air flow rate of 100 ml min(-1). The emission products from the VCI-apparatus were analysed qualitatively and quantitatively by gas chromatography coupled with a mass selective detector (GC/MSD). A mechanistic scheme for the formation of thermal degradation products is presented.