Section 1606
SECTION 1606. Plastic Light Diffusers in Ceilings. (a) General. Ceiling light diffusers having an area greater than ten percent of any 10.00 square meters of room area shall be of approved plastics conforming to the requirements specified in this Code. (b) Installation. Plastic light diffusers shall be installed in such a manner that they will not readily become detached when subjected to room temperature of 80ºC for 15 minutes, Excepts, for the plastic light diffusers which are installed in the first floor area of Group C Occupancies having egress directly to the exterior of the building; and plastic light diffusers which are located between an approved automatic fire-extinguishing system and the area to be protected other than public corridors for Group A, B, C, D, E, G, H and I Occupancies if tests required by the Secretary have established that such installation will not interfere with the efficient operation of such automatic fire-extinguishing systems.