One of the most important safety tools in your car are the air bags, it’s quite surprising that they haven’t been talked about more.

We’re pretty sure most of you have heard of the air bags at least once. But how many of you actually know when they’re deployed.

Let’s look at the crux, when should your air bags deploy?

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When Should Your Air Bags Deploy?

Frontal air bags are generally designed to deploy in “moderate to severe” frontal or near-frontal crashes, which are defined as crashes that are equivalent to hitting a solid, fixed barrier at 8 to 14 mph or higher. (This would be equivalent to striking a parked car of similar size at about 16 to 28 mph or higher.)

At What Speed Should Airbags Deploy?

In modern cars, the airbag control unit continually monitors a number of crash parameters through sensors connected to it. When the crash is severe enough that the airbags need to deploy, electrical circuits connecting the inflators to the airbag control unit are completed and gas generators in the inflators produce nitrogen gas to fill the bags.

Typically, a front airbag will deploy for unbelted occupants when the crash is the equivalent of an impact into a rigid wall at 10-12 mph. Most airbags will deploy at a higher threshold — about 16 mph — for belted occupants because the belts alone are likely to provide adequate protection up to these moderate speeds.

How Do Air Bags Know When To Deploy?

How do they know when to deploy? Sensors in the car detect when an impact has happened. The sensors send a signal indicating sudden deceleration to a computer inside the car. The computer determines the severity of the crash and then, if necessary, triggers the airbags to deploy.

The airbag will only deploy in more serious crashes. It won’t deploy in low-speed crashes in which seatbelts alone should provide enough protection, for example.

How do they inflate? The airbag is inflated by a chemical reaction. A compound called sodium oxide explodes when it’s heated up, releasing nitrogen gas into the bag to make it expand. This reaction takes just milliseconds (a fraction of a second).

At the same time that this reaction is happening, another part of the system is producing a cloud of gas to help protect people’s heads from hitting the steering wheel or dashboard. This is made by igniting solid pellets of sodium hydroxide and potassium nitrate (saltpeter) at very high temperatures — which also creates nitrogen gas.

What happens once it’s inflated? When you hit something, you come to a sudden stop because you’re hitting an object that can’t move out of your way and has more mass than you do.

Can Airbags Deploy Without Impact?

As you’ve no doubt guessed, the answer is “it depends.” The airbag will only deploy if the vehicle’s sensors detect the correct speed, braking, and impact. A malfunctioning sensor can cause the airbag to activate when there isn’t a crash, or not deploy when a crash occurs.

Under normal circumstances, there is nothing you can do to set off an airbag while you’re driving down the road. You’d have to be in an accident first. That said, there are some things you can do to trick the sensors into deploying your airbags — and we wouldn’t recommend them.

Here’s how it works: Your vehicle’s impact sensors measure deceleration — that is, how fast something stops moving. These sensors trigger the airbags when they detect rapid deceleration of 3-25 gs. (A “g” is a unit of acceleration equal to 32 feet per second squared.)

At 25 gs — which is equivalent to hitting a wall at 25 mph — every part of your body would stop as suddenly as if it had hit a brick wall. You’re unlikely to survive such an impact without an airbag (or at least not in good enough shape that you’ll care about messing up your car afterward).

Do Airbags Deploy At 200 Mph?

There’s a myth that airbags explode at 200 MPH. As you might expect, this is not true.

The myth began after the NHTSA (National Highway Traffic Safety Administration) published some test data showing that a bag deployed at 200 MPH would have reached its full-on deployment in less than ten milliseconds. The NHTSA did not publish the test data and this myth has continued to be perpetuated.

Airbags are made of polyurethane — a high-density, closed cell material that can withstand considerable heat and pressure. They’re inflated by inflating a cylinder within the bag itself with nitrogen, and then quickly blowing out the air to create a powerful force to push the occupant away.

When you’re in an accident, the deployment of your airbag sends you flying forwards or backwards out of harm’s way, but as it’s trying to do that, it also has to slowly deflate so it doesn’t damage the passenger compartment or injure anyone who is not wearing their seat belt.

A good airbag system’s deployment speed is important because there is a dangerous period between when the bag is deployed and when it begins to deflate. This “fly open” period is about 12-18 inches (30-45 cm), which is enough time for a passenger to be injured by the blast.

At What Impact Speed Do Side Airbags Deploy?

Cars are designed to be safe and protect us in the event of a crash. However, not all vehicles are created equal, and neither are all car safety features.

Side airbags are designed to deploy during a side impact collision and protect you from serious injuries to your head, neck and torso. However, they will only deploy if the accident is significant enough to trigger them.

There is no single speed that causes side airbags to deploy. Instead, several factors work together to determine whether or not side airbags will go off in a side impact crash – including vehicle construction, type of crash and the speed of the crashing vehicle.

Do Airbags Deploy Without Seatbelts?

Yes, airbags will deploy in a crash even if the person is not wearing a seatbelt. However, that does not mean it is safe to drive without a seatbelt.

The main reason airbags are there is to protect you from hitting something else, like the dashboard or steering wheel. Without a seatbelt, you would be thrown around in the car during the crash and could hit things inside the car with your head, chest or other body parts. This can cause injuries and even death.

Airbags are designed to fill up the space between your body and whatever you might hit during the crash (like a dashboard) so that your body hits the airbag instead of something harder. You would not be able to hit an airbag if you were bouncing around in the car, so then airbags would be useless.

The idea of an airbag is that it prevents injury by slowing down your body’s movement with the “soft” material of the bag instead of letting you hit another object at full speed.

In addition, seatbelts prevent you from being thrown from your vehicle in case of a crash. If you are thrown from your vehicle, there might not be anything for the airbags to protect you from except for flying out of your car window.

How Often Do Airbags Malfunction?

The airbag failure rate is a perennial concern for drivers. If you’re concerned about whether your vehicle has been recalled to fix an airbag problem, you should check the vehicle’s VIN (vehicle identification number).

The VIN is a 13-digit code found on the driver’s side door frame and stamped on the inside of the driver’s door, just out of sight.

If you see a NHTSA recall or “service action” letter, it means that a problem was found with an airbag component made by Takata Corp., which is based in Japan. Those vehicles were manufactured from 2001 through 2003 at plants in Michigan, Texas, Alabama and Georgia.

Since Takata was pulled off the U.S. market in 2014 because of its defective airbags, automakers have been required to replace those components at no cost to owners.

But there are still two kinds of airbags that could be defective: those made by Takata and those made by other companies. If your vehicle has one of these non-Takata airbags, it might be worth checking to see if it has been recalled.