IIHS Advisories | No. 18, November 1995
Airbags save lives but can pose some risks especially to infants, young children
The overall performance of air bags has proved them to be very effective in reducing fatal and serious injuries from motor vehicle crashes. Institute research concludes that air bags have reduced driver deaths in frontal crashes by about 20 percent. Driver and passenger air bags now are standard in nearly all new passenger cars. They are in more than 50 million vehicles on the road, and it's estimated that these vehicles will have been involved in more than 650,000 deployments by the end of 1995. Now that there has been a large number of deployments, some adverse side effects in addition to the benefits are becoming evident. Of particular concern are reports of eight infant and child fatalities caused by air bags.
Most Air Bag Injuries Are Minor, But Some People Are More At Risk
It's important to note that air bags aren't devices that protect every occupant in every crash from all types of injury. They're designed to work with safety belts in front and front-angle crashes, the most common kind of serious crash. Side air bags, which are being installed in a few car models, work to protect occupants in side-impact crashes. It is the energy of an inflating air bag that in some circumstances can cause occupant injuries, usually minor but occasionally serious or fatal. An Institute study of data from the National Accident Sampling System found that 96 percent of air bag-related injuries are minor, such as contusions or abrasions; 3 percent are moderate, such as concussions and simple fractures; fewer than 1 percent involve serious injuries, including a small number of fatalities. People who are close to an air bag when it begins to deploy are especially vulnerable to injury. This group includes people who because of their short stature sit close to the steering wheel, in particular elderly people who are more likely to be injured by a deploying bag because of their fragility; infants in rear-facing child safety seats; and unbelted or improperly belted occupants who move forward early in a crash or during pre-crash braking.
The recent deaths of some young children are of particular concern. Several air bag-related fatal injuries have been in low-severity crashes in which it's probable that no injury or only minor injury otherwise would have occurred. The National Highway Traffic Safety Administration (NHTSA) is investigating these and seeking help from automakers and the public to identify ways to minimize adverse air bag effects. In addition, NHTSA issued a warning that children unprotected by a safety belt or other child restraint could be seriously injured by a deploying air bag. The agency warns motorists to make sure children always are restrained properly. This maximizes their protection in all kinds of crashes and assures they're not in a dangerous position if an air bag deploys. Toddlers and older children should ride in the back seat. If they must ride in front, the seat should be moved away from the air bag as far as possible.
NHTSA also warns parents not to place infants in rear-facing child safety seats in the front passenger seat of vehicles equipped with passenger air bags. In December 1991, NHTSA first warned consumers to place infants in rear-facing safety seats in the back seats of cars with passenger air bags. In September 1993, the agency announced that air bag-equipped cars must have warning labels on the sun visors and information in the owner's manual informing parents about the correct use of safety seats in cars with passenger air bags. Five months later, NHTSA announced that all new rear-facing infant seats must have a clearly visible warning against using them in a seating position equipped with an air bag. In a deployment, an inflating bag could hit the back of the seat with enough force to seriously injure an infant. In vehicles in which infant restraints can fit only in the front seat, such as pickups and sports cars, NHTSA is allowing manufacturers to install a manual cut-off switch to deactivate the passenger air bag as a temporary measure to address this problem until a better solution can be devised.
Future Air Bags Should Help Reduce Injury Problem
Air bags must deploy very quickly to protect occupants in frontal crashes, fully inflating in a fraction of a second. The energy of the inflating bag is the source of injuries. There's no single solution to this problem, but many things can and will be done to reduce air bag-associated injuries. Under consideration are regulatory changes that would permit manufacturers to reduce the energy in a bag, allowing somewhat slower deployments without significantly reducing protection in high-speed crashes. This could reduce air bag-related injuries to both belted and unbelted occupants. Having higher deployment thresholds for people using belts than for those without belts can eliminate additional air bag injuries to belted occupants in low-severity crashes. These systems are used today in Mercedes and BMW cars. When occupants don't use belts, the air bags deploy in crashes equivalent to hitting a solid barrier at about 9-12 mph, the typical deployment threshold. Thresholds are higher — more like 16 mph — for people using belts because they're less likely to be injured in lower-speed crashes. Since a large number of air bag deployments occur in crashes equivalent to barrier impacts at between 10-15 mph, this design can eliminate a large number of deployments unnecessary to protect belted occupants.
Manufacturers also are developing advanced air bag systems that use more sophisticated technology to sense occupant position and whether people are belted and to use this information together with data from crash sensors to adjust bag deployment speeds and pressures. These "smart" air bags are currently under development, but extensive testing must be completed to assure the reliability of these more complex systems. They're not expected to be available for many years.
The combination of lap/shoulder belt and air bag provides optimum protection in all crash types, so drivers should ensure that all occupants are properly restrained. Drivers should always use belts and sit as far away from the steering wheel as they comfortably can. Passengers should buckle up and sit as far away from the instrument panel as possible. Infants in rear-facing restraints must be placed in the back seat of vehicles equipped with passenger air bags. If a child older than one must ride in front, make sure the child is secured in a safety seat or properly restrained with a lap/shoulder belt and the passenger seat is moved as far back as it goes.