An object in motion stays in motion unless acted upon by an external force. Before air bags, that external force was either the steering wheel, dashboard, or windshield of the vehicle.

Thanks to air bags, drivers and front-seat passengers in vehicles have additional head, neck, and chest protection in the event of a collision. But how, exactly, do air bags work? The Bountiful car repair experts at Master Muffler have the details.

How Air Bags Work

Did you know there’s a chemical reaction occurring in your vehicle to deploy the air bags in your vehicle? Air bags inflate thanks to the reaction between sodium azide (NaN3) and heat. When heated, sodium azide produces both nitrogen gas and sodium. The nitrogen gas is what inflates an air bag, and the sodium is mixed with other elements to make it less toxic for passengers.

What Triggers Air Bags

Airbag sensors located at the front and sides of a vehicle (if it contains side air bags or SABs) detect a certain amount of impact. Most air bags are designed to respond if the impact resembles hitting a solid surface anywhere between 8 and 14 miles per hour. At this force, the sensors activate an igniter compound in canisters of sodium azide. The heat produced causes the sodium azide to release nitrogen gas, which inflates the air bags in 0.03 seconds.

Air bags are designed for single-use, so if they deploy in a crash it’s important to have them replaced. If the car isn’t salvageable, you don’t have to worry about this particular car repair, which can cost up to $5,000 with parts and labor.

Why Do We Have Air Bags?

When worn properly, seatbelts do a lot to prevent a person from being flown from the vehicle. And they’ve been mandatory in vehicles since 1986. However, it’s still possible to collide with the interior structures of the car when wearing a seatbelt, which can cause a lot of harm. Combined with air bags, seatbelts increase your likelihood of survival in a crash.

Frontal air bags have been standard in cars in 1998, while SUVs, trucks, and vans started including them in 1999. To this day, side air bags are still optional in many makes and models of vehicles.

You may be wondering why we still mandate the use of seatbelts if air bags are meant to protect us in a crash. Well, the force of an airbag is extremely strong. Without a proper seatbelt restraint, an airbag could hit a person’s body in the wrong place and cause more harm than injury prevention. Air bags are meant to work with seatbelts, not to replace them. Without a seatbelt, the impact of an airbag hitting you could actually kill you. 

In the unfortunate event of a collision, our Bountiful car repair team is here to help you assess the damage and work on what repairs we can.

Why Do We Use Air Bags If They’re Dangerous?

When used with proper seatbelt restraints, air bags are intended to cushion a person’s head, neck, and chest at the time of impact. They also distribute the transfer of energy created upon impact, deflecting it from directly hitting your body.

If you’re questioning the importance of air bags, note that from 1987 to 2017, the National Highway Traffic Safety Association (NHTSA) reports that frontal air bags saved over 50,000 lives. Furthermore, the NHTSA states that in 2017 alone, 2,790 lives were saved by air bags, including passengers age 13 and older. This is important to note because air bags are not designed for protecting children younger than 13; always ensure small, young children are securely seated in the backseat where they will be safer. 

What’s the Deal with the “ON-OFF” Switch?

You may have a vehicle equipped with an air bag ON-OFF switch. Why would it be an option to temporarily disable your air bags if they’re instrumental in saving lives? Sometimes circumstances call for turning off the air bags to accommodate your passengers. If you have no choice but to put a rear-facing infant seat in the front passenger seat of your vehicle, you should disable that air bag. If you have a child under 13 who, for medical reasons, needs to sit up front while you drive, you should disable the passenger air bag. If you, as the driver, are so small you need to sit just inches away from the steering wheel (if you’re 4’6” in height or less), you should disable the driver’s side air bag. Ideally, you should be sitting at least 10 inches from the steering wheel for best results if the air bag deploys.

Keep in mind that reactivating air bags isn’t as simple as flipping a switch. In fact, deactivation is also an involved process. Only an NHTSA authorized car dealer or car repair shop is permitted to turn off an air bag with consent.

Why Didn’t My Air Bag Inflate?

If you were recently involved in a collision and your air bags didn’t deploy, it may be because the impact was considered moderate via the air bag sensors. Additionally, some passenger-side bags temporarily disengage if the seat senses an underweight passenger. If you’re driving a previously-owned vehicle, it’s possible your air bags didn’t deploy because they have already done so and were never replaced.

The Bountiful car repair technicians at Master Muffler are here to help you better understand your vehicle and how to care for it. Contact us today if you have questions about something, and refer to our online coupons for your next service!