What gas is used to inflate air bags in vehicles?

The gas commonly used to inflate airbags in vehicles is nitrogen. When an airbag deploys, it needs to inflate rapidly to provide protection during a collision. Nitrogen is preferred for several reasons: it is inert, meaning it doesn't react with other substances, and it is readily available, making it cost-effective for manufacturers. The fact that nitrogen doesn't support combustion is also a vital safety feature in the event of an accident involving fire.

Using nitrogen helps ensure that the airbag inflates quickly and then deflates after impact, minimizing the chances of injury to the occupants. Other gases, such as carbon dioxide or oxygen, are not suitable for this purpose due to their potential to react chemically or present other safety hazards. Helium, although light and non-toxic, does not provide the necessary pressure and volume for rapid airbag inflation. Thus, nitrogen remains the standard choice in vehicle airbag systems, ensuring both effectiveness and safety.