Get Help Now


Wisconsin Car Safety Features Part 2: How Do Airbags Work?

Airbags are a mandatory safety feature on American cars. Since 1998, passenger vehicles in the United States are required by law to have air bags on both sides of the front seat. Some cars are also available with side airbags. There are several names for airbag systems, including:

  • Supplementary Restraint System (SRS)
  • Air Cushion Restraint System (ACRS)
  • Supplemental Inflatable Restraint (SIR) 

Airbags protect your head, neck, and chest areas and reduce the risk of death in a head-on Milwaukee car crash by about 30 percent. However, airbags must be used with a seat belt to be most effective. How do airbags work? Our Milwaukee accident attorneys explain.

A brief course in automotive safety engineering

Some people believe that airbags stop the body from being thrown forward during a Wisconsin car accident. Actually, it is the seat belt that restrains the body. The airbag actually protects the occupant’s head from hitting the steering wheel, dashboard, or windshield. When the seat belt and airbag work together, a person may survive a serious car accident with only minor injuries.

When the sensors in a car detect a Milwaukee car accident, they send a signal to the module that controls the airbags. The sensors in newer cars are able to measure the speed and severity of the collision and determine which airbags should deploy.

Once the control module determines that the airbags should deploy, it sends a signal to an igniter or squib inflator. This is an electrical device that sends a current through a thin bridge wire. The current causes the wire to overheat and ignite the airbag propellant. The airbag propellant is made of sodium azide. This substance burns quickly and produces a large amount of nitrogen gas, which inflates the nylon airbags. The process takes only 30 milliseconds—that’s three hundredths of a second.

When a person’s head hits the nitrogen-filled air bag, the bag absorbs some the energy of the impact. To release the energy, the bag begins to deflate by letting the gas escape through tiny holes. A person inside the car may see a puff of smoke. This is actually cornstarch or talcum powder that is placed in the bag to keep it from sticking together. Both the gas and the powder are harmless.

Side airbags work differently. As in front airbags, the control module signals the igniter. The igniter melts a tiny bladder inside a cylinder that stores argon gas, compressed to a pressure of 3000 to 4000 pounds per square inch. The argon then fills the airbags. Argon gas is harmless.

The risks from airbags

Sometimes, airbags are defective. Recently a man was injured when his car’s airbag inflated. The airbag loosened a metal bracket, which sliced the man’s ear. The government is now investigating airbags in the 2012 Hyundai Elantra.

Have you been injured by an airbag? Talk to a Milwaukee accident lawyer about your accident. You may be eligible for monetary compensation for your injuries. To learn more, contact Hupy and Abraham at 800-800-5678 or request a free copy of our book, The Ultimate Guide For Automobile Accident Victims.

Jason F. Abraham
Managing Partner, Hupy and Abraham