Every highly flammable material storage room and every picker or shredder room shall be provided with one or more windows, skylights or other ventilating opening facing a public way, private alley, yard or other open space not less than 15 feet wide, with closures arranged to open for natural ventilation and having a combined area of not less than five percent of the total wall area of the room. The required combined area of openings which are arranged to open for ventilation shall be provided with sashes or dampers, or other closures which shall be hung overbalanced and held in place in such manner that an explosion or fire within the room will cause such sash, damper or closure to open for its full area; provided, however, that in lieu of such requirements it shall be permissible to provide a vent flue or flues extending directly to the outside air, which shall be used solely for the purposes of ventilating such room, which shall have a combined area of not less than five percent of the total wall area of the room, with an inclosure of the same fire-resistive value as is required for the inclosures of the room, and equipped with a normally closed noncombustible trap door arranged to open automatically in case of explosion or fire within the room. No such window, skylight, ventilating opening or vent flue required by this section shall be nearer than four feet, six inches to any other building or structure on the same premises or to any interior lot line.
(Prior code § 92-42)