From left, Hiroshi Shimizu, senior vice president of global quality assurance at Japanese air-bag maker Takata, Rick Schostek, executive vice president of Honda North America, and Scott Kunselman, Chrysler's senior vice president of vehicle safety and regulatory compliance, prepare to testify before the Senate Commerce Committee hearing on Nov. 20 on air bags linked to multiple deaths and injuries in cars driven in the U.S. (J. Scott Applewhite/AP)

The company whose defective air bags will result in one of the largest vehicle recalls in history stopped short of endorsing an expanded nationwide recall in a contentious Senate hearing Thursday.

Sen. Edward J. Markey (D-Mass.) challenged Takata Vice President Hiroshi Shimizu about whether his company supported a nationwide recall rather than limiting the recall to humid regions where the air bags have been known to malfunction.

“It’s hard for me to answer yes or no,” Shimizu said.

“It’s not hard to answer yes or no,” Markey responded.

“I can’t answer,” Shimizu said.

“I’m going to take that as a no,” Markey said. “I think that you’re plain wrong. Your company is making a big mistake in not supporting [a nationwide] recall.”

The National Highway Traffic Safety Administration called Tuesday for a nationwide recall of vehicles equipped with Takata driver-side air bags, a move that could involve 20 million cars and cost Takata an estimated $852 million.

NHTSA Deputy Administrator David Friedman said after the hearing that he would take steps to enforce the recall unless automakers voluntarily comply.

Takata air bags are installed in 1 in 5 vehicles worldwide, including many models of the domestic and foreign cars sold in the United States.

NHTSA has been investigating whether Takata air-bag inflators that have been exposed to consistently high humidity are responsible for 130 injuries and at least four deaths in the United States and one in Malaysia. Humidity may cause the bags to deploy with so much force that they spray drivers with shards of metal from their steel inflators.

Senate Commerce Committee Chairman Bill Nelson (D-Fla.) compared the air bags to a “live hand grenade” poised at a driver’s chest. He called on the U.S. Transportation Department to level fines of up to $1 million a day on automakers who don’t give owners a replacement vehicle to drive until the faulty air bags are replaced.

Facing executives from two of the affected manufacturers — Chrysler and Honda — Nelson said they should be “providing . . . a loaner or rental car to people who potentially would be driving a death trap.”

The two executives said they would provide vehicles to customers when their recalls take effect but stopped short of offering to provide them immediately. Honda, with 45 injuries and four deaths attributed to Takata air bags, began recalling cars for air-bag replacements in 2008. More than 5 million Hondas ultimately may be subject to recall.

“We understand the urgency of the current situation and are taking proactive steps to encourage Honda and Acura owners to get their vehicles repaired at an authorized dealership,” Rick Schostek, executive vice president at Honda North America, told the committee.

Friedman said he would push the automakers to send letters to all owners of cars equipped with the air bags.

“Until they step up for the American public, my hands are tied, frankly, to help people understand who is at risk,” Friedman said.

Friedman told the committee that Takata was guilty of poor quality control and record keeping.

“We know that Takata hasn’t always provided the automobile industry with accurate information,” he said.

In one of the hearing’s most tense moments, Sen. Dean Heller (R.-Nev.) asked Shimizu whether Takata took “full responsibility for these tragic deaths” linked to its air bags.

Shimizu, who had been testifying in English, paused and then consulted with an interpreter.

“We recognize that three victims’ cases are related to our products,” Shimizu said after a brief discussion. “The other two are under investigation.”

Nelson described Shimizu’s pause before responding as “painful.”

Both Schostek and Scott Kunselman, Chrysler's senior vice president for vehicle safety and regulatory compliance, equivocated when Markey asked whether they supported a nationwide recall.

“Each of you should be saying yes,” Markey said.

When Heller asked Schostek whether his daughter’s Honda was safe to drive, he wasn’t happy with the imprecise response.

“It was clear you weren’t sure how to respond,” Heller said.

Since 2013, 7.8 million vehicles have been recalled, most of them in regions of the United States with high humidity. Now NHTSA wants a national recall by Takata and 10 automakers — BMW, Chrysler, Ford, General Motors, Honda, Mazda, Mitsubishi, Nissan, Subaru and Toyota — who use their bags in some models.

Takata contended this week that it has tested close to 1,000 of its air bags in regions where humidity is low and that none of them has ruptured dangerously. The company says a nationwide recall may put “lives at risk” by diverting replacement air bags from regions that need them most.

The emergence Thursday of a fatality attributed to a Takata air bag in arid Arizona gave a new twist to pinning down the cause of the deadly deployments.

Markey and Sen. Richard Blumenthal (D-Conn.) called a news conference before the hearing to discuss the case of Charlene Weaver, who died of multiple skull fractures and brain hemorrhages as the result of an air-bag deployment when she was riding in a 2004 Subaru Impreza in 2003.

“We need to learn the details,” said Friedman, who was unaware of the incident.

Markey and Blumenthal have called for a federal criminal investigation into whether the company sought to cover up the defects after they first surfaced in 2004.

“Reports that Takata concealed and destroyed test results revealing fatal air-bag defects, along with other evidence that the company was aware of these deadly problems, clearly require a criminal investigation by the Department of Justice,” Blumenthal and Markey said in a joint statement this month. “If the reports are true, the company must be held accountable for the horrific deaths and injuries that its wrongdoing caused.”

The report, published in the New York Times earlier this month, described the accounts of two unnamed former Takata employees who said the company attempted to cover up the defects when they were discovered during 2004 testing at Takata’s American headquarters in Auburn Hills, Mich.

Friedman said after the hearing that his agency has been cooperating with a Justice Department investigation since September.

Shimizu told the committee that replacement bags and those now being installed in new cars pose no risk.

“We are confident that the air bags Takata is producing today, including the replacements for recalled units, are safe,” Shimizu said.

In a new report published Thursday, the Times said Takata’s decision to switch to a new formula using ammonium nitrate may be responsible for the defect caused by temperature and humidity changes.

Shimizu didn’t respond directly when questioned about the potential defect.

“The question was not answered,” Nelson said in the hallway after he adjourned the hearing. He said Shimizu, Schostek and Kunselman did “the shuffle, two step and side step” in response to many of the questions.

Nelson and Sen. John Thune (R.-S.D.) said they would introduce legislation to encourage whisteblowers from the automotive sector to come forward with “original information” about defects or attempts to cover them up.

“We want them to come forward,” Thune said at Thursday’s hearing, alluding to the numerous auto recalls this year. “The public’s confidence has been shaken. What steps could have been taken?”