Air bags are not inflated from some compressed gas source but rather from the products of a chemical reaction. The chemical at the heart of the air bag reaction is called sodium azide, or NaN. Image: NEW CAR ASSESSMENT PROGRAM, CRASH TEST AREA. CRASHES trip sensors in cars that send an electric signal to an ignitor.lthough we don't usually associate automobiles with chemistry, a lot of chemistry takes place in a working car--the burning of gasoline to run the engine, for example, and chemical reactions in the battery to generate electricity.