What Are Airbags?

a deployed airbag
on Seidman

Airbags are passive restraints that activate when a vehicle gets into an accident. Unlike traditional seat belts, which only work if the driver or passenger buckles up, airbags are designed to activate automatically. All new vehicles in the United States have to include dual front airbags, but many automakers go above and beyond that minimum requirement.

In some cases, it’s possible to deactivate one or more of the airbags in a vehicle.

When that is possible, 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.

How Do Airbags Work?

Airbag systems typically consist of multiple sensors, a control module, and at least one airbag. The sensors are typically 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 can also be monitored by the airbag control unit. If specific conditions are detected, the control unit is capable of activating the airbags.

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

When predetermined conditions are detected by a control unit, it is capable of sending 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 can be fully inflated within about 30 milliseconds.

After an airbag has been deployed once, it has to be replaced. The entire supply of chemical propellants is burned through in order to inflate the bag a single time, so these are single use devices.

Do Airbags Really Prevent Injuries?

Since airbags are 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 a number of severe injuries that could be directly associated with airbag deployments. However, the NHTSA also estimated that the technology saved over 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. In order 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 was very 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 a number of 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 that are mounted in other locations.