Does Polyboard burn?
Very slowly and very clean. Polyboard more than meets the requirements of UL94HB Test for Flammability of Plastic Materials. The Specific Maximum Burning Rate is 40.0 mm/min whereas the Burning Rate of Polyboard is only 21.9 mm/min. The FMVSS No. 302 Flammability Test also certifies that Polyboard burns at 0.15 inch per minute, far better than the Pass Rate that stipulates that the fire cannot burn or transmit a flame front across its surface at a rate of more than 4 inches per minute.
