Every grinding or dust-producing room, shall have means of natural ventilation or vent flues as required by Section 15-28-260 for material heating rooms; provided, however, that the combined area of ventilating opening which shall have closures arranged to open automatically in case of explosion or fire shall be not less than ten percent of the floor area of the room, and the combined area of vent flues, in lieu of ventilating openings shall be not less than eight percent of the floor area.
(Prior code § 92-97; Amend Coun. J. 6-14-95, p. 2841)