Air bags are designed to protect your head, neck, and chest from hitting the dash, steering wheel, or windscreen when involved in a collision. They are designed to deploy if the vehicle crashes into a solid object at any speed over 15 kph. Sensors detect any rapid changes in the deceleration of the vehicle and send an electric signal that inflates the air bag. In a collision, the air bag will inflate and deflate within a split second. It won't suffocate you or restrict your movement. The "smoke" that is emitted into the vehicle is a non-toxic powder substance used to lubricate the air bag.
In combination, air bags and seat belts are a proven safety system which have saved many lives. However, even with air bags there have been major injuries in crashes of low or moderate severity. Consider, that an air bag is slightly larger than the steering wheel and will inflate with over 1000 pounds of pressure. It will extend back about 20-30 cms and make contact with your face, neck and chest. As a result, there will be some pain to these areas of the body. If your hands are on the steering wheel they will be immediately knocked off and anything between you and the air bag (ie. sunglasses, a drink, or your hands) will be forced into your face. Furthermore, air bags could seriously injure or kill a small child who is sitting in the front seat.
Some vehicle manufacturers have redesigned their air bag systems. They have repositioned the vents to minimise the risk of burns caused by escaping nitrogen gas on deflation. Additionally, the shape of the air bag has been modified to reduce abrasions and deployment threshold speeds have been altered to prevent inflation at lower speed. Air bag design should continue as the advancement of technology and research is gained.
