U.S. sticks to ruling that 50 million airbag inflators are unsafe, moves closer to massive recall

DETROIT — U.S. auto safety regulators say they stand by a finding that more than 50 million airbag inflators are dangerous and should not be used, which is one step closer to a mass recall.

The decision Wednesday by the National Highway Traffic Safety Administration concerns inflators made by ARC Automotive Inc. in Tennessee and another parts maker. The move comes despite opposition from automakers.

Inflators in approximately 49 million vehicles from 13 manufacturers may explode and throw shrapnel among drivers and passengers.

The agency said the inflators have been responsible for at least seven injuries and two deaths in the United States and Canada since 2009.

NHTSA said seven of the inflators exploded in the field in the United States, each showing evidence of insufficient welds or too much pressure in a canister designed to contain the explosion and fill the air bags in a crash.

The agency also said that 23 of the inflators ruptured during testing, due to causes common to those of the devices that exploded in the field. In addition, four inflators ruptured outside the United States, killing at least one person, the agency said.

“It is certain that the vast majority of the inflatable devices in question will not rupture upon deployment,” NHSTA wrote. “However, based on the evidence linking past ruptures to the same friction welding process, all of the inflatable devices in question are at risk of rupture.”

Several automakers argued in public comments that NHTSA had not found a safety defect and that none of the millions of inflators in their vehicles had burst.

But NHTSA said the only way to know which of the ARC-designed inflators will explode is to see them deploy in a crash. Federal motor vehicle safety law “does not permit such a defect to go uncorrected,” the agency said.