N.J. Stat. § 5:3-18
Every such portable booth shall conform strictly to the following specifications and so far as possible shall meet the requirements and specifications of a permanent booth:
Such booth shall be at least six feet in height, inside measurements, and shall have an area of at least twenty square feet if only one moving-picture machine is to be operated therein, and an additional twenty square feet for each additional machine.
It shall be constructed with a framework of angle iron not less than one and one-quarter inches by one and one-quarter inches by three-sixteenths of an inch thick. The iron members of said framework shall be spaced not more than four feet apart on the sides, and not more than three feet apart on the front, back and top of such portable booth.
It shall be completely covered on all sides, top and bottom with either twenty-four gauge steel plate, or one-quarter inch asbestos boards, except that if the bottom is covered by asbestos boards, said boards shall be at least three-eighths of an inch thick. The floor of such portable booth shall be elevated above the permanent support on which it is placed by a space of at least one-half inch.
Every portable booth shall have a door not less than two feet in width and five feet ten inches in height, consisting of an angle iron frame covered with either the aforesaid steel plate or asbestos boards, and attached to the framework of such booths by hinges, in such manner that the door shall be kept closed automatically at all times when not used for ingress or egress.
The windows in such portable booth, used in connection with the machine and by the operator thereof, shall not be larger than is reasonably necessary to secure the desired service. The said steel plate, or asbestos board, shall be provided for each window, and shall be so suspended and arranged that it will automatically close the window upon the operation of either a fusible or mechanical releasing device with a fusible link attached.
Such portable booth may be of a folding type, but in such case it must be so constructed that when it is assembled for use it shall be rigid with all points tight.
N.J.S. § 5:3-18