Various components of a Takata airbag, from a Honda automobile, were displayed before the start of a Senate Commerce, Science and Transportation Committee hearing on Nov. 20. (Gary Cameron/Reuters)

The manufacturer of automobile air bags that have killed at least five people and maimed scores of others sidestepped on Tuesday the demand for a nationwide recall of tens of millions of vehicles, setting up a confrontation with federal regulators determined to force the company’s hand.

In a statement to U.S. regulators, the Japanese company Takata outlined its response to the crisis, but stopped short of complying with a demand by the National Highway Traffic Safety Administration. The NHTSA wants regional recalls expanded to include all U.S. vehicles equipped with air-bag inflators that have sprayed drivers with shrapnel when deployed.

NHTSA Deputy Administrator David J. Friedman, in testimony prepared for a House committee hearing Wednesday, reiterates his intent to force what is mushrooming into one of the largest vehicle recalls in history. He has threatened to seek a $7,000-per-vehicle fine against Takata.

At the hearing, members of the House Committee on Energy and Commerce are expected to confront Hiroshi Shimizu, a Takata senior vice president, with the suspicion that his company has replaced air-bag inflators in more than 8 million vehicles with devices no better than the ones being recalled.

“Takata has not disclosed whether it has made any changes to the design specifications or manufacturing processes for the replacement inflators,” says a memo prepared for the hearing by the committee’s staff. “In discussions with staff, most vehicle manufacturers indicated that they were replacing the inflators with ‘like’ parts, indicating that it was the same inflator with the same propellant presumably manufactured the same way but of a newer vintage.”

A committee staff member familiar with the memo said, “Our members are hoping to gain a better understanding at [Wednesday’s] hearing of what is different and what improvements, if any, have been made in the manufacturing process.”

Takata did not respond Tuesday when asked to comment on the suggestion that the replacement parts might not be better than the recalled ones.

On Tuesday, Toyota, which has recalled 878,000 vehicles in the United States, called for independent testing of Takata air-bag inflators.

In prepared testimony, Abbas Saadat, a Toyota vice president, explains his company’s position: “Like you, we want additional assurances about the integrity and quality of Takata’s manufacturing processes, particularly in light of previous experiences.”

Toyota is one of 10 automakers involved in air-bag recalls in the past six years, along with Honda, Mazda, Mitsubishi, General Motors, Subaru, Ford, Chrysler, BMW and Nissan.

Takata has been testing its inflators to find the cause of defects first identified in 2008. The company, which supplies one in five air bags worldwide, has identified production mistakes in one of its U.S. plants and exposure to high humidity as likely causes.

“Based on the data currently available and our best engineering judgment, Takata continues to believe that the public safety is best served if the identified areas of high absolute humidity remain the priority for the replacement of suspect inflators,” Shimizu says in testimony prepared for Wednesday’s hearing.

In testimony before a Senate committee last month, Shimizu said the company was confident that its current line of air bags is safe.

The company is in a precarious position. It has admitted that it cannot produce replacement air bags fast enough to meet the demand if the U.S. recall goes nationwide, even as it rushes to replace recalled air bags globally. Takata’s competitors say they could help fill the gap but would want long-term commitments from automakers to justify the expansion. Shares in the company have plunged 57 percent this year.

“We recognize that NHTSA has urged Takata and our customers to support expansions of the current regional campaigns in the United States,” Takata chief executive Shigehisa Takada said in a statement Tuesday. “We will take all actions needed to advance the goal of safety for the driving public, including working to produce additional replacement units to support any further recalls that may be announced by our customers.”

Sen. Bill Nelson (D-Fla.), who chaired last month’s Senate hearing on Takata air bags, responded to the company’s statement by saying, “Anything short of a nationwide recall is unacceptable.

“Just look at the thousands and thousands of people who come to Florida from colder climates each year,” Nelson said. “Don’t they face the same risks as people who live in humid areas year-round?”

Neither Takata nor any of the five automakers that the NHTSA wants to issue a nationwide recall — Honda, Ford, Chrysler, Mazda and BMW — has agreed to do so. The NHTSA last week took the first formal step toward forcing a recall, demanding that Takata declare that millions of vehicles sold in the United States are equipped with defective air bags.

“While a decision to keep the Takata air-bag recall regional may help the supplier address the near-term concerns it doesn’t answer the larger questions related to injuries and deaths that have occurred outside these humid areas,” said Karl Brauer, senior analyst at Kelley Blue Book. “If more injuries or deaths happen outside the recall zones, it further damages Takata’s image while calling into question NHTSA’s understanding of the problem.”

NHTSA released a statement after receiving Takada’s formal submission Tuesday.

“We received Takata’s response to our Special Order and will immediately begin reviewing the documents as part of our ongoing investigation into ruptured Takata air bags,” the statement said.

Air bags are among major automotive-safety advances that are credited with saving millions of lives worldwide. When vehicle sensors detect a collision they ignite a solid wafer of chemical propellant inside the metal cannister of the air-bag inflator. The chemical reaction creates a gas that causes the air bag to inflate within milliseconds, emerging from the steering wheel or dashboard.

But if the propellant burns faster than intended, it creates more gas than the vents into the air bag can handle. The metal cannister can break into fragments that spray the driver or passengers.

Takada announced in Tuesday’s statement that the company had recruited three former U.S. secretaries of transportation to review its current air-bag production and advise the company on its handling of the crisis.

Samuel K. Skinner, who served as transportation secretary and White House chief of staff under President George H. W. Bush, has been asked to help with an audit and independent report on the manufacturing process.

Rodney E. Slater, secretary under President Bill Clinton, and Norman Mineta, secretary under President George W. Bush, “will advise the company as we address the current challenges we face,” Takada said.