Sections 5:3-10 to 5:3-14 of this title shall not apply to the use in a classroom or auditorium of a public school building for instructional purposes, of standard portable or semiportable moving-picture machines called "projectors" , if the projector case is of fireproof construction and a mazda lamp is used for light. Such machine must also be equipped with a fan and vent over the lamp for cooling purposes, and with an automatic fire shutter that cuts off the heat from the film when the machine is not in motion.
Such machine must be approved by the board of education of the school district in which the school is situated, and shall be operated by a school teacher or other person over eighteen years of age who is employed by such board of education, who is competently trained to operate such machine.
All films shall be housed in fireproof containers while pupils are in the room.