For short and tall passengers, safety air bags may pose a serious injury hazard, U.S. researchers say in a study calling for new safety standards to be introduced.

Craig Newgard, an emergency medicine and public health professor at Oregon Health and Science University, studied data from over 65,000 crashes that took place over 11 years and found that air bags were harmful to people smaller than four foot 11 and taller than six foot three.

Transport Canada says drivers and passengers should position themselves at least 25 centimetres away from the air bag cover.
(CBC)

"While air bags are modestly protective for mid-stature occupants, they appear to increase the risk of injury for large and small stature adults," Newgard said in the study published in the May issue of the Academic Emergency Medicine Journal.

Newgard said the many "smart" air bags use body weight to determine how the bags will deploy. He proposed that engineers should consider factoring in a height component. Until then, people not of medium height should not sit in the front passenger seat in a vehicle that has been equipped with an air bag, he said.

Drivers in Canada can have their vehicles equipped with an on-off switch for their air bags, however Transport Canada says the safety devices should only be disabled in specific cases, including for infants in rear-facing car seats and people with unusual medical conditions.

The federal agency also notes that deactivating air bags should be considered for drivers who because of medical reasons cannot position themselves at a distance so their sternum is at least 25 centimetres back from the air bag cover.

Children under the age 12, because they have a tendency to lean forward, along with drivers who cannot sit with their sternums at a 25-cm distance away from their air bag should also consider installing an on-off switch.