NFPA 257

1.1 Scope. 1.1.1 This standard prescribes standardized fire and hose stream test procedures that apply to the evaluation of fire window assemblies, including windows, glass block, and other light-transmitting assemblies intended to retard the spread of fire through openings in fire resistance–rated walls. 1.1.2 This standard is not to be construed as determining the suitability of fire window assemblies for continued use after fire exposure. 1.1.3 This standard provides a standardized method for comparing the performance of fire window assemblies.