Laws on Automobile Air Bags

••• airbag image by Dimitar Atanasov from

Air bags save lives – over 50,000 lives between 1987 and 2017, according to the National Highway Traffic Safety Administration (NHTSA). That puts them in the same category with seat belts as essential vehicle accessories. And, like with seat belts, the installation and use of air bags is regulated by state and federal laws. It's easier to understand and appreciate government efforts to require working air bags in vehicles in this country after getting a thorough understanding of what air bags are and how they protect drivers and passengers.

What Are Air Bags?

Air bags are protective equipment in motor vehicles. The bags deploy quickly and automatically during an automobile crash, putting a cushion between the occupant and the windshield. There are frontal air bags and side-impact air bags, both types designed to open in moderate or severe crashes. They reduce the chances that an occupant's upper body or head will smash into the vehicle's interior during a crash.

Most people recognize that their bodies tend to move forward in a car when the driver throws on the brakes. During a crash, that movement is even more sudden and violent. That's a function of the laws of motion. Essentially, everything that moves has mass and speed, resulting in kinetic energy. The heavier the mass and the faster an object is moving, the more kinetic energy it has.

When a vehicle stops suddenly, the people inside tend to keep on moving until something stops them. Although seat belts restrain a person's body, their heads are not restrained so during a crash, they will smash into the steering wheel or the windshield. The purpose of air bags is to stop that from happening.

How Do Automotive Air Bags Work?

Air bags are not filled with air, but rather with chemical explosives. That makes them both quick and effective, but also potentially dangerous. The air bag's deployment is triggered when a car loses speed quickly. An electronic chip in the air bag system detects this and triggers the circuit that sends an electric current through a heating element, igniting a chemical explosive. The explosive generates harmless gas that inflates a bag behind the steering wheel that provides cushioning for the occupant's head.

While the initial air bags were located behind the steering wheel, passenger vehicle makers gradually began adding air bag modules in other locations. From the year 2000, it became commonplace to install side-impact air bags on all new vehicles. A new vehicle today can contain up to 10 air bag modules, including: driver, passenger, side-curtain, seat-mounted, door-mounted, pillar mounted side-impact, knee bolster, inflatable seat belt and pedestrian modules.

Note that air bags are not stand-alone protection. Although initially considered an alternative to seat belts, this proved untrue. Today they are designed to work in tandem with seat belts. In fact, they are now termed a "supplementary restraint system" to indicate that they are not intended to replace seat belts but to work with them. The belt restrains a person's body and prevents them from flying out of the vehicle during impact. Air bags are designed to protect the person's head and shoulders only. Relying on air bags without fastening a seat belt is extremely dangerous.

When Are Air Bags Dangerous?

Air bags have to work fast and somewhat violently to be effective. After a crash, the chemical reaction inflates the bag in less than 1/20th of a second. Given how fast they deploy, they can cause serious injuries to an occupant who is too close to the bag or who comes in direct contact with it as it begins to deploy. Occupants may suffer eye injury or hearing loss as a bag deploys.

Modern air bags have been engineered to deploy less violently and with less force than older designs, reducing accidental deaths. All in all, it is important to know, understand and follow the laws about air bags since they are designed with driver and passenger safety in mind.

Risks to Children

The biggest risk is to young children who might be smothered by deploying bags. That's why children under the age of 13 are usually required to ride in the back seat. Starting in 1991, the National Highway Traffic Safety Administration started warning about the danger of air bags for younger children, who could be suffocated or injured by them.

By 1993, federal law required a child warning on every car that was equipped with an air bag. By 1997, a warning on the front sun visor was mandated in all cars. It must state that air bags could potentially kill or seriously injure children under the age of 13 and that all young children should ride in the back seat and not the front seat.

Does the Law Require Air Bags?

Air bags, like seat belts or safety belts, were once just a good idea. Now they are mandatory equipment in new cars, trucks and vans, just as seat belts are. Unlike seat belts, air bags are passive safety equipment; the driver/passenger does not need to take any action to make air bags work, while, for seat belts, they must actively put the belt on. The regulation of seat belts and air bags have been linked from the start.

Congress passed the National Traffic and Motor Vehicle Act in 1966. This Act required automakers to install seat belts in every vehicle they built. It did not mention air bags. In fact, it did not require vehicle occupants to use seat belts either, and, as it happened, most people didn't use them.

At first, the government didn't want to mandate seat belt use. And when air bags appeared in commerce, it was thought that the air bag equipment would take the place of seat belts – that it would offer drivers and passengers protection during car crashes whether they opted to use the seat belt or not. Eventually, regulators determined that three-point shoulder belts were more protective than air bags and that air bags were more effective when used with seat belts.

Federal Regulations for Air Bags

The first federal law regarding air bags was effective in 1997. It mandated that at least 90 percent of all new vehicles for the 1997 model year must be equipped with driver-side air bags. The following year, the law required all new automobiles to be equipped with dual air bags as a standard feature. By 1999, this requirement was extended to all light truck and vans. Today, air bags and three-point seat belts are mandated as standard equipment in all motor vehicles. And, in most states, seat belt use is mandatory under the law.

What About Recalls of Air Bags?

Not every air bag put into vehicles worked well. In 2015, air bag inflators manufactured by Takata were found to have a defect in their ammonium nitrate propellant. This defect ultimately was linked to 15 deaths and some 250 injuries in this country. The U.S. Department of Transportation recalled the Takata air bag inflators. The recall involved 70 million air bag inflators installed by 19 vehicle manufacturers. Takata went bankrupt.

Driving After Air Bags Deployed

Seat belts can and should be used by vehicle occupants every time they are in a moving car. Even if the car is in an accident, the driver and passengers usually do not have to replace the seat belts; once the body damage is repaired, the same seat belts usually work just fine. However, this is not true with air bags. It is not possible to undo an inflated air bag. The chemical has been tripped and the gas released. There is no going back. So what happens then? Can a driver continue to drive without getting new bags installed?

Cars with deployed air bags can technically be driven. However, when they deploy, the emergency seat belt pre-tensioners usually trigger as well. These are the mechanisms that cause the belt to clamp tightly in an accident. After an accident, the belt might still lock when it is clicked, but the mechanism that clamps the belt in an accident may not work. And, of course, driving a car after airbag deployment means that neither the driver nor passengers have air bag protection.

Driving With Nonfunctional Air Bags

There is no federal law that forbids driving a car that is not equipped with functional air bags. This is partially because air bags were not required on older cars and some of those cars are still on the road. The federal air bag laws mandate the installation of air bags in new vehicles, but are silent about any requirement to replace deployed air bags.

Some states require working air bags under safety inspection standards. In these states, a car cannot pass a safety inspection without functional air bags, and technicians must check this whenever they inspect a vehicle. But in other states, this is not an issue or is only required in specific instances. For example, anyone selling a vehicle in Alabama must inform a buyer that the air bags are not working. In Hawaii, Maine and Massachusetts, every car owner must get an annual safety inspection that includes verification that the air bags function. This is also the case in Pennsylvania, Vermont and Virginia.

Many states rely on a driver's insurer to force replacement of air bags once they are deployed in a crash. Insurance rates and terms depend on the vehicle's features, including air bags. A car that had air bags when insured may be declared a total loss by the insurer if the air bags no longer function. Such a vehicle can only be assigned a salvage title. In many states, a salvaged car cannot be driven on the street until the safety equipment is rebuilt and the car passes inspection.

Frequently Asked Questions

Question: When did air bags become mandatory in cars?

Answer:​ The first law making air bags mandatory was enacted in 1996. By that time, many auto makers had already added air bags to their vehicle designs, starting in the 1980s. Since the enactment of the first federal law, air bag technology continues to improve year after year.

Question: Is there air in an air bag?

Answer:​ No. The air bag is inflated not by a release of air, but by a chemical reaction. It breaks down a compound stored in the air bag, causing nontoxic gas to inflate the nylon bag. Passenger cars with air bags have sensors that activate when the car gets into a crash. As this sensor is triggered, it acts very quickly to transmits an electric signal to the ignitor. The heat from the ignitor separates the chemical compound into nitrogen gas and sodium metal, and this inflates the bag very quickly.

Question: How fast does an airbag open?

Answer:​ An air bag opens incredibly quickly. If you have ever wondered how air bags can cushion a person in a vehicle from a head-on collision before they even feel the impact, it's because of the fraction-of-a-second release. Air bags are released and filled in fractions of a second at a rate as fast as 200 mph.

Question: Why are air bags dangerous to children?

Answer:​ Given the speed at which air bags deploy, it is no surprise that a violent air bag deployment would put kids at risk. That's why the government advises and/or requires adults to put their young kids in the back seat. Today, air bag technology has advanced to permit a level of inflation that is modified in response to the size of the person sitting in the front passenger’s seat.

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