All nitrate film shall be kept in closed containers except during the actual time it is being worked upon or examined. It shall not be placed or kept under benches or other shelves which shield it from the discharge of sprinklers. Scrap nitrate film shall be kept separate from wastepaper, safety film and other rubbish and shall be kept in steel drums or metal containers with tight covers. It shall be disposed of at frequent intervals. Discarded film in full or part rolls shall be kept in such containers, and neither scrap film nor discharged film shall be baled or burned.
Rewinding of nitrate film shall be performed in a special rewind room in an approved location or in the projection room. If done in the projection room, approved enclosed-type rewind machines shall be used and approved. Containers for scrap film having a self-closing hinged cover shall be provided.
Nitrate motion-picture film used in connection with the projection of motion pictures (as in theaters, motion-picture theaters, screening or projection rooms, sound recording studios, television studios and motion-picture titling studios) shall be limited and kept as follows: The quantity of nitrate film in any projection room not equipped with an approved system of automatic sprinklers shall be limited to that given below. If equipped with an approved system of automatic sprinklers, double the quantity specified may be permitted.
A. 
In a projection room constructed of brick, hollow tile, concrete or other approved masonry, not exceeding one hundred twenty-five (125) pounds [twenty-five thousand (25,000) feet of thirty-five-millimeter film].
B. 
In a projection booth constructed of metal frame covered with asbestos board or sheet iron, not exceeding seventy-five (75) pounds [fifteen thousand (15,000) feet of thirty-five-millimeter film].
No collodion, emul acetate or other similar flammable cement or liquid in quantities greater than one (1) pint shall be kept in the projection booth.
Splices in film shall be made on mechanical cutting and splicing machines.
A. 
Motion-picture projectors using nitrate film shall be operated or set up for operation only within an approved enclosure, not less than forty-eight (48) feet square in area and seven (7) feet high. If more than one (1) machine is to be operated, an additional twenty-four (24) square feet shall be provided for each additional machine.
B. 
For new construction such an enclosure shall not be less than eight (8) feet wide, ten (10) feet deep and eight (8) feet high for one (1) projection machine and not less than fourteen (14) feet wide, ten (10) feet deep and eight (8) feet high for two (2) machines.
C. 
The entrance door into the enclosure shall be at least two by five (2 x 5) feet, shall be of construction equivalent to the sheathing permitted above for rigid-frame construction, shall be self-closing, swinging out, and shall be kept closed at all times when not used for egress or ingress.
D. 
For new construction at least two (2) doors shall be provided, each not less than thirty (30) inches wide and six (6) feet high. Doors shall be approved fire doors of a type suitable for use in corridor and room partitions. Exits shall be in accordance with requirements of authorities having jurisdiction, particularly as to size and location. At least one (1) shall be of the conventional stairway type having a suitable landing at the top or opening directly onto a corridor.
E. 
Two (2) openings for each motion-picture projector shall be provided. The one for the projectionist's view (observation port) shall be not larger than two hundred (200) square inches and the other through which the picture is projected (projection port) shall be not larger than one hundred twenty (120) square inches. Where separate stereopticon or spot- or floodlight machines are installed in the same enclosure with picture machines, not more than one (1) opening for each such machine shall be provided for both the operator's view and for the projection of the light, but two (2) or more machines may be operated through the same opening. Such openings shall be as small as practicable and shall be capable of being protected by approved automatic shutters. Each opening shall be provided with an approved gravity shutter set into guides not less than one (1) inch at sides and bottom and overlapping the top of the opening by not less than one (1) inch when closed. Shutters shall be of not less than ten-gauge iron or its equivalent or of one-fourth-inch hard asbestos board. Guides shall be of not less than ten-gauge iron or its equivalent. Shutters shall be suspended, arranged and interconnected so that all openings will close upon the operating of some suitable fusible or mechanical releasing device, designed to operate automatically in case of fire to isolate the contents of the enclosure from other portions of the building. Each shutter shall have a fusible link about it, and there shall also be one (1) located over each upper projector magazine, which upon operating will close all the shutters. There shall also be one (1) located over each upper projector magazine, which upon operating will close all the shutters. There shall also be provided suitable means for manually closing all shutters simultaneously from any projector head and from a point within the projection room near the exit door. Shutters on openings not in use shall be kept closed.
F. 
All shelves, furniture and fixtures within the enclosure shall be constructed of noncombustible material. No combustible material of any sort whatever shall be permitted or allowed to be within such enclosure, except the films used in the operation of the machine and film cement.
G. 
Ventilation shall be provided by one (1) or more mechanical exhaust systems which shall draw air from each arc lamp housing and from one (1) or more points near the ceiling. Systems shall exhaust to outdoors either directly or through a noncombustible flue used for no other purpose. Exhaust capacity shall be not less than fifteen (15) nor more than fifty (50) cubic feet per minute for each arc lamp, plus two hundred (200) cubic feet per minute for the room itself. Systems shall be controlled from within the enclosure and shall have pilot lights to indicate operation. No dampers shall be installed in such exhaust systems. Ventilation of these rooms shall not be connected in any way with ventilating or air-conditioning systems serving other portions of the building.