What Are Airbags?

These safety devices are, on balance, useful and necessary

Airbags are passive restraints that activate when a vehicle senses a collision. Unlike seat belts, which only work if the driver or passenger buckles up, airbags are designed to activate automatically at the precise moment that they are needed.

All new vehicles in the United States include front airbags for the driver and passenger, but many automakers go beyond that minimum requirement.

Airbags in an automobile cross-section
Lifewire / Brooke Pelczynski

Turning Airbags Off

Airbags are designed so that they don't have to be turned on, but it is sometimes possible to turn them off. When a vehicle includes the option to disable the passenger side airbags, the deactivation mechanism is usually located on the passenger side of the dash.

The disarming procedure for driver’s side airbags is typically more complicated, and following an incorrect procedure can cause the airbag to deploy. If you are concerned that your driver's side airbag may injure you, then your best course of action is to have a trained professional disable the mechanism.

How Do Airbags Work?

Air bag safety demonstration with test dummy
Romilly Lockyer / Getty Images

Airbag systems typically consist of multiple sensors, a control module, and at least one airbag. The sensors are placed in positions that are likely to be compromised in the event of an accident, and data from accelerometers, wheel-speed sensors, and other sources feed the airbag control unit. If specific conditions are detected, the control unit activates the airbags.

Each individual airbag is deflated and packed into a compartment that’s located in the dash, steering wheel, seat, or elsewhere. They contain chemical propellants and initiator devices that ignite the propellants.

When predetermined conditions are detected by a control unit, it sends a signal to activate one or more initiator devices. The chemical propellants are then ignited, which rapidly fills the airbags with nitrogen gas. This process occurs so quickly that an airbag fully inflates within about 30 milliseconds.

After an airbag has been deployed once, it must be replaced.

Do Airbags Really Prevent Injuries?

Because airbags activated by a type of chemical explosion, and the devices inflate so quickly, they can potentially injure or kill people. Airbags are particularly dangerous to small children and people who are seated too closely to the steering wheel or dash when an accident occurs.

According to the National Highway Traffic Safety Administration, there were around 3.3 million deployments of airbags between 1990 and 2000. During that time, the agency recorded 175 fatalities and several severe injuries directly associated with airbag deployments. However, the NHTSA also estimated that the technology saved more than 6,000 lives during that same time frame.

That’s a remarkable reduction in fatalities, but it’s vital to use this life-saving technology properly. To reduce the potential for injuries, short-statured adults and young children should never be exposed to a front airbag deployment. Children under the age of 13 shouldn’t sit in the front seat of a vehicle unless the airbag is deactivated, and rear-facing car seats should never be placed in the front seat. It can also be dangerous to place objects between an airbag and a driver or passenger.

How Has Airbag Technology Evolved over the Years?

The first airbag design was patented in 1951, but the automotive industry proved slow to adopt the technology. Airbags didn’t show up as standard equipment in the United States until 1985, and the technology didn’t see widespread adoption until years after that. Passive-restraint legislation in 1989 required either a driver’s side airbag or automatic seat belt in all cars, and additional legislation in 1997 and 1998 expanded the mandate to cover light trucks and dual front airbags.

Airbag technology still works on the same basic principles that it did in 1985, but the designs have become remarkably more refined. For a number of years, airbags were relatively dumb devices. If a sensor was activated, the explosive charge would be triggered and the airbag would inflate. Modern airbags are more complex, and many of them are automatically calibrated to account for the position, weight, and other characteristics of the driver and passenger.

Since modern smart airbags are capable of inflating with less force if conditions warrant, they are typically safer than first-generation models. Newer systems also include more airbags and different types of airbags, which can help prevent injuries in additional situations. Front airbags are useless in side impacts, rollovers, and other types of accidents, but many modern vehicles come with airbags mounted in other locations.

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