Fire Behaviour, Smoke and Toxic-Effluent Assessment of Printed Photopolymer Systems: Test Scale and Material State

Fire behaviour is not a single material property. Ignition time, heat-release rate, mass-loss rate, smoke production and toxic-effluent composition depend on imposed heat flux, ventilation, specimen thickness, orientation, backing, surface area and the actual cured formulation. Printed photopolymers add internal voids and anisotropic geometry, while additive-manufacturing studies show that geometry, porosity and composition can affect ignition and heat-release behaviour relative to conventionally produced specimens. Bench-scale cone calorimetry is valuable for heat release and dynamic smoke, while single-chamber smoke testing and FTIR effluent analysis answer different questions. ER-390 therefore requires the fire scenario and specimen state to accompany every result and prohibits direct conversion of a bench-scale ranking into a full-product fire-safety claim. It also separates finished-material fire response from manufacturing fire prevention, which remains outside this review.