We use "Modified EPS" which contains flame retardant additives that improve its burning characteristics compared to the EPS variety we are so familiar with in our disposable cups and packaging materials. EPS products will progressively distort, soften and melt when exposed to temperatures in excess of 175°F. As exposure temperatures continue to increase, combustible gases given off by molten residue will ignite in the presence of an ignition source. This temperature level, referred to as the flash ignition point, is approximately 700°F for modified EPS. This value may be directly compared to flash ignition temperatures for white pine and Douglas fir of 500° F.
Unlike wood, however, MEPS makes a very small fuel contribution because it contains only about 3% combustion material by volume.
In addition, most building codes require interior wall and ceiling surfaces covering foam insulations to provide a 15-minute rated fire barrier. panels meet this requirement with the installation of drywall on interior surfaces.