Even as Takata, the Japanese auto supplier, has acknowledged that its air bags are prone to rupture and has vastly expanded its recall, the company has maintained that the underlying explosive that powers the air bags can be used safely.
At a congressional hearing this week, lawmakers questioned a Takata executive about the safety of the propellant, called ammonium nitrate.
Ammonium nitrate, which Takata has used in its propellant since the early 2000s, has become a central concern over the air bags, which can explode violently when they deploy, sending metal shards into the cabin. According to experts, it is highly sensitive to moisture and to changes in temperature. Over time, the propellant can break down, making it prone to combusting violently.
Kevin Kennedy, an executive vice president for Takata, defended the company’s continued use of ammonium nitrate.
“We believe that when properly manufactured and designed, ammonium nitrate - phase-stabilized ammonium nitrate - can be done properly,” Kennedy said. He was referring to one of the changes the company’s engineers had made to stabilize the compound to prevent it from breaking down. Takata’s new design would alter the shape of the propellant wafers, but not the composition.
At least six deaths and more than 100 injuries have been linked to the airbag defect.
Some lawmakers questioned why the compound should be used at all, given the circumstances.