Entire underside of body including floor members, wheel housings, and side panels below floor level shall be coated with fire resistant asphalt base, rubber base, or other undercoating material, applied by spray method to seal, deaden sound, insulate, and prevent oxidation. Any undercoating material used shall be asbestos-free. Do not cover up or obliterate the chassis identification plate.
All school buses shall be equipped with an effective exhaust type ventilation system, static non-closeable type installed in low-pressure area of roof, capable of ejecting foul air under all operating conditions. System shall be adequately weatherproof and dustproof.
Wheel housings shall be constructed of sixteen (16) gauge or heavier steel and be rigidly reinforced, shall be attached to floor and side panels in such manner as to prevent water or dust from entering body, and shall be designed for easy removal of tires. For materials see STRUCTURAL DESIGN; for covering see FLOOR AND FLOOR COVERING.
Side Windows, Passenger, Standard: There shall be either a standard or a push-out type window accessible for each passenger seat except where it is not possible because of the installation of side emergency exits or lift door. Buses may have one less set of passenger windows than rows of seats provided that each seat has access to a window.
Standard side windows: shall open from the top only and shall operate freely. All side windows except the driver's and the service door windows shall be split sash type with positive latch. Side windows that can be latched in an uneven position are not acceptable. The passenger side windows shall provide an opening at least twenty-two inches (22") wide and between nine and thirteen inches (9" and 13") high, with minimal obstruction by the seatbacks or other objects.
Side Windows, Passenger, and Push-out Type: These windows shall be hinged at the top or front and shall be positioned for ease of egress. These windows shall provide an emergency opening at least twenty-two inches (22") wide and thirteen inches (13") high, with minimal obstruction by seatbacks or other objects. These windows shall meet or exceed Federal Standards. Push-out windows shall be equipped with an electrical switch connected to an audible signal automatically operated and located in the driver’s compartment, which shall indicate when the window is released. The switch shall be enclosed to prevent tampering. Wires leading from the switch shall be concealed in the walls. No cut-off switch shall be installed in the circuit.
Service Door and Emergency Door Windows: All glass panels in the emergency and service doors for all buses shall be safety glass panels, permanently closed, and shall be set in a waterproof manner.