History

• Airbags were developed in WWII for airplanes. Although the patents started in the 1950s, airbags did not appear in automobiles until the 1970s. The first car maker to install airbags in every model was Chrysler in 1988. Airbags have been required on every new American cars since 1998. So far there are no federal requirements for side airbags.
  
  

Function

• Airbags appear exactly when needed and protect the passenger from the rapid deceleration caused by hitting the car frame at crash speed. It is important that the airbag start deflating as soon as it is hit. It accomplishes this by having thousands of tiny holes. The force of the collision starts deflating the airbag and decelerates the passenger at the perfect rate to minimize injury.
  
  

Mechanism

• A spring holds a ball at one end of a cylinder. When a sufficient force is applied from the right direction, the ball moves to the other end of the cylinder, making an electrical connection. A small amount of a chemical that is used to launch fireworks is exploded into the airbag. Another chemical in the airbag combines with chemicals from the explosion to make a small residue of inert chemical and an enormous quantity of nitrogen gas. The white powder seen when an airbag inflates is not from the explosives. It is talcum powder that was put in to keep the airbag flexible during its long storage.
  
  

Benefits

• Airbags save lives. They also reduce injuries. By providing a carefully controlled gradient of deceleration, the human body comes through the crash relatively unharmed.
  
  

Warning

• It is possible to be injured by an airbag. Usually this is caused by the passenger hitting the airbag early. For full protection, it is important that nobody sit with his face directly in line with an expanding airbag. The National Highway Traffic Safety Administration recommends that passengers set at least 18 inches from an airbag.