A small folded up fabric bag in many automobiles of today. Often in the center of the steering wheel, and on the dashboard on the passenger side. They use tiny MEMS sensors to detect an accident, and then using gas they inflate in an instant to help absorb the impact and cushion the passengers.

They have a nasty tendency to be harmful when little children are placed in the passenger seat, especially those in a car seat.

Device which is supposed to deploy a large bag of air at the moment of impact in a car collision in an effort to save people from driving their heads through their dashboards. However, this seems to cause more fatalities than planned, as the airbag deploys bloody fast, causing a whiplash effect.

I still don't get how people can be so lazy to ignore seat belts...

What it's like to experience an airbag:

You probably won't notice. It happens impossibly fast. It goes a little something like this:

  • You're driving along, or maybe stopped, minding your own business.
  • Whatever mishap is going to take place starts to take place. Someone pulls up or stops short in front of you, someone behind loses control, whatever. If you're unlucky, you might see it coming and it'll haunt you in the future.
  • There is a sudden, massive jolt. You are thrown forward and may, in that split-second, see an opaque green/blue/grey mass coming up to meet you.
  • You are bounced back into your seat. Your car is filled with dust, and either the hood or trunk is bent obscenely upwards.
  • The realization that something bad has happened sets in to your shocked mind, as you notice your car has stopped and your airbag is sitting, deflated, across your steering wheel.
  • That's all there is to it. It inflates in a fraction of a second, absorbs your face, and then deflates.

    In terms of injuries (as I skirt GTKY territory) I was lucky. Both my forearms were severely burned and scratched and bloodied by the airbag, I had a large red mark on my shoulder from the seatbelt, but I was otherwise fine - thanks to the assembly workers in Holland who had fitted the airbag to my car nine years previously. To avoid broken arms or wrists, I think a sensible grip on the wheel is necessary - my right hand struck the ignition key and bent it 45 degrees, because I was holding the wheel at 4 and 10 o'clock. Had it been at three o'clock or higher my right arm might have gone into the side of the door or into the dashboard, snapping my wrist.

    Replacing a spent airbag is not cheap - your steering wheel will be ruined and the new airbag and wheel combination will set you back in the order of hundreds of dollars/pounds. This is assuming your car is not wrecked. The steering wheel should still operate, though. You'll also finally see what an airbag looks like - they're usually a dull colour, roughly the size of a beachball, and made from tough, somewhat rough to the touch material. After use it will likely flop down to the bottom of the steering wheel, but not further (I have no experience of passenger-side airbags, which I believe are significantly larger)

    The most important thing to remember about airbags is to still wear your seatbelt! Without the seatbelt, you'll just slip across the top of the airbag on your exciting but lethal voyage into (and through) the windshield.


    J. Totale: I was driving a Volvo when I had my incident, and I have to disagree that they or other safety-centric car manufacturers waste money on safety features. As I've said, I was lucky. My car had good handling and was not impeded by the weight of all of its airbags and side-impact beams. It saved me from much worse, and I am thankful for that.

    I also disagree with the previous suggestions about removing airbags in favour of preventative measures. Accidents happen, that's why they're called accidents, and no amount of careful planning against disaster can prevent the odd mishap. And if that one mishap avoids being a fatality by virtue of an airbag, it was worth that airbag being installed.

    "Seat belts, pff! They kill more people than they save!"
    "That's not true, you're thinking of airbags!
    - Homer and Lisa Simpson


    A nice idea in theory; you're in a crash, and before your head snaps forward on your neck, a nice soft bag comes up to gently cushion your skull, then disappears immediately so you can see to still control the car.

    Airbags deploy in under a quarter of a second, and when used in conjunction with a seat belt they can be effective in staving off whiplash and other head injuries for the average person. Note I said 'average person'. Most people are not average, and in cases where the driver (or passenger) is shorter than what the engineers of the system have decided, fatalities can occur from airbag deployment. Of the deaths that have been attributed to airbags, most of them were short adults and children.

    The airbag is usually activated when crashing at speeds of 25km/h or over, and should only activate in front or rear collisions (A bag inflating at speeds toward your face is of no use if your car is hit side on). Exceptions to this are cars produced by companies who consider themselves to be formost experts in safety; like Volvo, whose newer cars have over twenty airbags for all passengers. This is just stupid, and honestly, they should spend more time making a more controllable car than filling it with gimmicky safety features.

    Airbags are designed to deflate immediately (If you want a nice, air filled pillow, get some Fill-Air), the theory being that after the initial impact, then car will most likely still be moving, and the driver will be able to control the car better (to avoid a worse accident) if he can see. Good idea? Yes, but let's examine what happens: An airbag inflates at around 400km/h. This is fast enough to break your nose, cause other serious facial injuries, or even cause death. All of which has been known to happen. There is usually also a lot of dust released with the airbag, due to the installation process and the time between the car being made and the time the airbag is used. Also depending on how the driver's holding the wheel his hands/arms may get broken. This is worse than a punch in the face, so do you think you'd still be in a good state to steer a car and make decisions about the road? I wouldn't.

    Bullbars have been known to cause adverse airbag behaviour, upsetting the timing device and causing the airbag to operate either too late or too early. I laugh at the people in their Toorak Tractors.

    Summing up, in no way would I actively seek out a car with airbags. If I did buy a car with them, I would probably ask the dealership if they could be removed.

    Note: No legislature exists at the moment decreeing that airbags are standard (although some car manufacturers insist on making them standard among some of their models). Passive safety features are standard. Airbags are classified as active.
    For those chemically minded, here is the three step chemical reaction that inflates airbags, gathered from http://www.madsci.org/posts/archives/aug99/934263277.Ch.r.html

    This initial reaction forms sodium and hot nitrogen gas which inflates the airbag.
    2 NaN3 —> 2 Na + 3 N2

    The sodium byproduct of the first reaction and the potassium nitrate generate additional nitrogen in the secondary reaction.

    10 Na + 2 KNO3 —> K2O + 5 Na2O + N2

    And finally the previous two reactions leave potassium oxide and sodium oxide to react with the third component of the mixture, silicon dioxide, forming alkaline silicate "glass".

    K2O + Na2O + SiO2 —> alkaline silicate

    As you can see, the reactions in steps 1 and 2 release a great deal of nitrogen gas. It is this hot nitrogen gas that fills the airbag. The potentially harmful sodium created in step 1 combines with potassium nitrate in step 2 to produce more nitrogen, potassium oxide, and sodium oxide. The final result is nitrogen gas and alkaline silicate powder. The sodium produced in step 1 may also react with moisture, temporarily forming sodium hydroxide. Because these reactions occur so rapidly, the multiple steps in the reaction are in reality occurring simultaneously.

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