Cotton batting, either natural, artificial or manufactured, straw, dry vines, leaves, trees, or other highly flammable materials shall not be used for decorative purposes in show windows or other parts of commercial, industrial or institutional occupancies unless flameproofed; provided, that nothing in this section shall be held to prohibit the display of saleable goods permitted and offered for sale. Electric light bulbs or fixtures or any heat producing device in any building shall not be decorated with paper or other combustible materials whether flameproofed or not. Exit doors, exit lights, fire alarm sending stations, standpipes and fire extinguisher locations shall not be concealed or obstructed by any decorative material. (1975 L.M.C., ch. 23, § 1.)