HDi 406 Peugeots are equipped with two front side airbags as well as driver and passenger airbnags. The 406 is designed to protect passengers in full-frontal, frontal offset, side and rear impact, and roll-over situations. The front airbags are designed to employ progressively to lengthen the time of contact between bag and passenger. The driver's side bag displaces 45 litres inflated, while the passenger-side bag has a 90-litre capacity. The passenger bag has a conical profile with a larger surface area for better facial protection. The seatbelts incorporate a pyrotechnic pretensioner that deploys to hold passengers firmly in an accident, while torsion bar pressure limiters also control the seatbelts to allow for a wide range of occupants. The pretensioners use an electronic control unit and two generators producing a tractive force of 350kg to tighten the front belts before the passenger begins to move forward in a frontal impact. Sixteen-litre side bags protect head and thorax in side impacts, while the 406's headrests were lengthened to provide more whiplash protection. All seating positions are provided with headrests and lap-sash seatbelts. The two-section rear seat has been designed to withstand impacts from items located in the boot and a cross tube runs behind the seat frames to help the car withstand side impacts. Improved safety in the front footwell area comes from redesigned wing linings and padding. The 406's polyethylene fuel tank offers maximum impact resistance and a fuel cut-off system helps prevent spillage in a rollover.