According to a helpful FAQ from the Automotive Occupant Restraints Council, airbags deploy as a result of a simple but powerful chemical reaction. When your car is involved in a frontal collision with an object while travelling over 20km per hour, a motion sensor sends an electrical shock to a small capsule of sodium azide powder, which instantly turns into inert nitrogen gas. This gas fills a lightweight nylon bag, which pops out of a latched panel and covers your head and upper torso. Mind you, this all happens very quickly. It takes about 30 milliseconds for an airbag to deploy, while it takes 100 milliseconds to blink. Airbags start deflating within a second of their release. When coupled with seat belts, airbags save lives. According to the National Highway Traffic Safety Administration, airbags reduce the risk of fatalities and serious injury by 40 to 55 percent. Just rember to follow car recomdations. Never have a child in the front seats.