Make sure windows and glass blocks don't contribute to fire spread by following the testing provisions in the 2012 NFPA 257.
NFPA 257: Standard on Fire Test for Window and Glass Block Assemblies prescribes fire and hose stream test procedures that apply to fire window assemblies -- including window, glass block, and other light-transmitting assemblies -- intended for use in window openings to retard the spread of fire through openings in fire-resistive walls. It establishes controls of the fire test as well as performance criteria and results for reporting procedures.
NFPA 257 is referenced by NFPA 101®: Life Safety Code® when being used to set up a window fire resistance rating in a fire rated wall assembly. Essential for testing laboratories and manufacturers, the 2012 Standard edition contains updated references to ensure you're working with the latest information. (Softbound, Approx. 13 pp., 2012)