Based on our previous study, we can also assume that the improvement was due to the catalytic effect of P-based fragments from phospholipids and O-H radicals, as proposed in previous studies . The two flame retardants interacted with each other and co-worked on the matrix to lock in more carbon contents. These groups bearing inherent flame-retardant effects retard the heat release of the DGEBA epoxy matrix during combustion. In a fire incident, victims die due to the lack of oxygen and inhalation of toxic smoke; therefore, the reduction in COP and SPR clearly indicates the smoke suppression of epoxy thermosets . The fire hazard results of the EPECO blend are comparable and improved compared to those of studies presented in the literature .