Driving schools » Vehicles and Equipment » Air Bags

Air Bags

Air Bags

How do they work?

Airbags work with nitrogen. Sensors are connected to the bags, and they detect a sudden deceleration in a vehicle, thus, when a vehicle suddenly stops the sensors will start a chemical reaction by sending an electric pulse to a chemical propellant which produces the nitrogen gas we were talking about.

The response time of the sensor and the whole process does not even take one twentieth of a second. The nitrogen gas inflates the bags.

Though the airbags inflate when a sudden stop is detected there is a minimum threshold so people do not have to be worried that the airbag will activate at every stop.

The main purpose of an airbag is to prevent any part of your body or your entire body to go undesirable directions, that is, outside the car through the windshield or to bump your head against the steer wheel , the former situation in case you are not wearing a seat belt the latter in case you are.

The airbag should stop the passengers speed to zero, by absorbing their movement force. The way airbags are designed and placed has to be perfect, the synchronization required to make the whole system work is amazingly perfect.

Why can they sometimes be dangerous?

There are certain reasons why an airbag would stop being safe and turn into a dangerous device, the first factor to consider is how it is being used. Many people may think that seatbelts are not necessary since their cars are provided with an airbag, no bigger mistake than this: Airbags complement the safety offered by a seatbelt, they do not replace it. If you are involved in a car collision, without your seat belt on and the airbag activates and receives all the energy you generate at a sudden stop at high speed, it will not resist it, it will explode because of the high pressure, and release the nitrogen gas within it, right at your body. If you are lucky enough and the airbag does not explode, the energy that your movement generates against the energy that the airbag generates when it inflates will cause a strong damage to your body.

There is a very small chance that the gas contained within the bag will not be cooled by the refrigerants that are supposed to cool it up so it does not burn you when activated, remember that the combustion inside the bag is one of high temperatures, and that is why refrigerants are there, though sometimes accidents can happen this is not common at all.

Accidental deployment is the kind of accidents you do not want to have: just imagine yourself driving at 100 km per hour in the interstate while your airbag suddenly activates.

What about children?


And so: what about children? Well, this is an intriguing question, as airbags can seriously injure young children and babies when activated. Why? Because airbags were designed for adults, not for children. This is an important reason why not to have babies and young children sat at the front seat.

The energy and speed produced by an airbag should be the right one for the weight of a grown up man/woman, but imagine what that force would do to the delicate bones and skull of a baby!

Remember, the rules say you should carry children under 12 years of age at the back seat for their own protection, not only from the collision itself buy even from safety devices.

What is its purpose?

The sole purpose of airbags is to absorb the impact in case of collision (higher than 3G) and thus protect passenger in a vehicle. It is believed that an airbag can reduce probabilities of front passengers dying in a collision in up to 30%. There are many types of airbags, some are integrated to the front, some are lateral airbags and there are even side curtain airbags. A recent airbag has been designed to protect legs.

Though airbags are of great help in case of collision it is also a fact that they are not better than seatbelts and they cannot replace them. Matter of fact, an airbag can injure an occupant if this does not wear a seatbelt during the collision.

According to the law in the United States, all vehicle occupants that are 12 years old or younger must ride in the back seat, and it is preferred that they travel in the middle of the backseat if possible. It is mandatory for all and every single passenger to wear a buckled seatbelt.

Remember that the safest place for a baby is the backseat; and remember to never sit a baby in a rear-facing seat, as it is extremely dangerous when the car is equipped with a passenger-side airbag. If you frequently travel with babies remember to equip your vehicle with a booster in the back seat.

Remember that airbags do not work by themselves; they need the support of seatbelts to prevent passengers from injuries and even death. An airbag will protect front seat passenger not only from the collision itself by cushioning the passengers, but it will also keep the steering wheel and windshield far from the passengers´ heads.

It is strongly recommended to sit at an appropriate distance from the airbag, as it may injure whatever passenger is sitting too close to it. Here some important suggestions:
  • Always wear and buckle your seatbelt, no matter how short the ride is.
  • Make sure your seat belt is properly buckled and adjusted.
  • Place the lap belt as low as possible, never over the abdomen.
  • Make sure the shoulder belt goes over your chest.
  • Adjust the front seats so they are not too close to the airbag as it will need room in case it gets activated.