By David Shepardson and Paul Lienert
WASHINGTON/DETROIT (Reuters) - U.S. lawmakers on Tuesday stepped up pressure on federal regulators and Takata Corp (T:7312) to accelerate the recall of millions of airbag inflators, citing evidence that the Japanese company manipulated data to cover up problems with its products.
In another development on Tuesday, a group of 10 automakers said the cause of Takata airbag ruptures linked to 10 deaths and more than 100 injuries is a combination of exposure to humidity, design and manufacturing issues, and use of the volatile chemical ammonium nitrate.
Reuters reported on Monday that the National Highway Traffic Safety Administration (NHTSA) continues to investigate whether the recalls of nearly 29 million defective Takata inflators in the United States should be expanded to include another 70 million to 90 million inflators with ammonium nitrate.
On Tuesday, U.S. Senator Bill Nelson cited the Reuters report on the Senate floor, and said it was "puzzling" that NHTSA has allowed Takata to continue production of ammonium nitrate-based inflators indefinitely.
"Why aren't they taking a more aggressive approach? And what's going on after all of these inflators, based on what we see with ammonium nitrate, have been exploding?" asked the Florida Democrat, reiterating calls by senators for action on the issue.
The current recall may have to be redone, Nelson said, "because auto manufacturers are installing new live grenades into people's cars as replacements for the old live grenades."
NHTSA in a statement on Tuesday cited a consent order issued last November under which "all Takata ammonium nitrate-based inflators must eventually be recalled unless Takata can establish their long-term safety."
Former managers interviewed by Reuters described "chronic" quality failures at Takata's North American inflator plants, an assessment reflected in dozens of company emails and documents dating back to 2001. Those problems, the former managers said, make it difficult for the company and regulators to pinpoint which inflators – among tens of millions – pose a danger.
When exposed to moisture, ammonium nitrate, which is used to inflate the air bag, can cause the inflator to rupture with deadly force, spraying shrapnel into vehicle occupants.
The review by the automaker-backed Independent Testing Coalition and a Utah-based team from Orbital ATK (N:OA) found the ruptures were caused by a combination of three factors: ammonium nitrate propellant without moisture-absorbing desiccant, long-term exposure to repeated high-temperature cycling in the presence of moisture and "an inflator assembly that does not adequately prevent the intrusion of moisture."
In a statement on Tuesday, Takata said those findings were "consistent" with its own and those of Germany's Fraunhofer Group, which was hired earlier by Takata to conduct additional testing.
David Kelly, a former NHTSA acting administrator who is coordinating the coalition's activities, briefed NHTSA and congressional staff members on Tuesday on the findings. A NHTSA spokesman said the agency was reviewing the findings.
Kelly said the group planned to investigate newer inflators with drying agents - along with replacement airbags.
The study only covered inflators that do not have a drying agent, or desiccant. Most of the inflators with ammonium nitrate that have not been recalled have the drying agent.
The consortium, which includes Honda Motor Co (T:7267), Toyota Motor Corp (T:7203), Ford Motor Co (N:F), General Motors Co (N:GM) and Fiat Chrysler Automobiles NV (MI:FCHA) will next investigate the performance of all inflators being used as replacement parts for current recalls.