In addition to creating smoke, deployment also releases powder that is in the air bag folds to prevent them from sticking together. In order to protect the head and upper body in high-impact crashes, air bags must inflate so quickly, and with such force, that they can cause injuries. While most of these injuries are minor, consisting only of bruises and abrasions, some are more serious, such as broken arms. In extreme cases, such as when the head or chest is against the module when it opens, fatal injuries can result. People who sit close to the steering wheel are at higher risk of being injured by a deploying air bag than those who sit further away.
Small children are also very vulnerable.
Children under the age of 12 should always be seated in the back of the vehicle and should be properly restrained. Never allow a child to sit or stand near the dashboard. Whenever possible, Transport Canada sets standards of performance and does not stipulate that particular hardware be used by manufacturers. In the case of air bags, the Regulations specify vehicle test conditions and injury criteria for the effective protection of occupants. Already some possess two thresholds of activation, one that is appropriate for a belted occupant and another, lower threshold, for an unbelted person.