DETROIT — U.S. auto safety regulators have backed away from seeking a giant recall of nearly 50 million air bag inflators and will investigate further after the auto industry raised questions about whether all of the inflators are defective.
The move Wednesday by the National Highway Traffic Safety Administration is vastly different from a decision reiterated by the agency in January that the inflators made by ARC Automotive Inc. of Tennessee are defective, dangerous and should be recalled.
The agency has said inflators in about 49 million vehicles from 13 manufacturers are at risk of exploding and hurling shrapnel into drivers and passengers. They’re responsible for at least seven injuries and two deaths in the U.S. and Canada since 2009.
But in a document posted Wednesday in the Federal Register and dated Dec. 13, the agency said it considered comments on a decision from January seeking the recall. The auto industry pointed to technical and engineering differences between ARC inflators in vehicles made by different manufacturers. The comments also raised manufacturing-process variations at different plants that made the ARC inflators.
“Given the potential relevance of these issues to the agency’s decision making, including the appropriate scope of any recall, further investigation is warranted,” the agency said in the document.
A message was left Wednesday seeking comment from ARC, which is owned by by Yinyi Group of China.
NHTSA said Wednesday that it carefully considered the comments on its decision to seek a recall of all the inflators and decided that more investigation is warranted.
The agency said that in the coming weeks it will send more information request letters to ARC, vehicle manufacturers and air bag-module manufacturing companies.
In a supplemental decision in January, NHTSA said seven of the inflators have blown apart in the field in the U.S., 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.
In addition, the agency said 23 inflators have ruptured in testing with causes common to the inflators that blew apart in the field. Also, four inflators have ruptured outside the U.S., killing at least one person, the agency said.
“To be sure, the overwhelming majority of the subject inflators will not rupture upon deployment,” NHSTA wrote in January. “However, based on the evidence linking past ruptures to the same friction welding process, all of the subject inflators are at risk of rupturing.”
But several automakers argued in public comments that years of investigations by NHTSA did not establish a systemic design defect. Some said none of the millions of inflators in their vehicles have ruptured due to the cause pointed out by the agency.
NHTSA had said the only way to know which of the ARC-designed inflators will blow apart is for them to deploy in a crash. The federal motor vehicle safety act “does not allow such a defect to go unaddressed,” the agency said.