(Bloomberg) -- The Takata Corp. air-bag recall already affectinga dozen automakers in the U.S. may widen as the nation’s regulatorheightens its scrutiny of the devices.

Volkswagen AG, Daimler AG, Jaguar Land Rover and Tesla MotorsInc. are among carmakers still using Takata air bags with ammoniumnitrate, a chemical propellant that U.S. safety regulators are nolonger confident in. Transportation Secretary Anthony Foxx saidthose automakers could also be affected by recalls that alreadyinvolve about 19 million vehicles.

“Everyone’s got to be vigilant,” Foxx said in an interviewMonday at a U.S.-Japan Council conference in Tokyo. “Even thoughour focus has been on the 12 manufacturers that we know pose a riskto safety of our consumers, it doesn’t preclude companies fromdoing their own testing. Our investigation remains open, so Iwouldn’t preclude the possibility that other OEMs would beaffected.”

Takata fell as much as 2.9% to 806 yen in Tokyo trading Tuesday,extending its streak of consecutive declines to seven days, thelongest since April 2014. The shares plunged 40% last week.

U.S. order

The U.S. has taken unprecedented steps overseeing recalls ofTakata air bag inflators, which deploy too forcefully and haveinjured scores of motorists and killed eight people. The U.S.National Highway Traffic Safety Administration last week finedTakata as much as a record $200 million and ordered the company tophase out its use of inflators that use ammonium nitratepropellant.

U.S. senators Richard Blumenthal of Connecticut and EdwardMarkey of Massachusetts raised concerns about Takata’s solvency ina letter to NHTSA, according to a statement released Monday inWashington.

Takata’s viability began to be questioned when Honda Motor Co.,Toyota Motor Corp. and Nissan Motor Co. were among automakers whofollowed NHTSA’s order by saying they would no longer use theTakata inflators in models under development. Honda said it’s awareof evidence suggesting the supplier manipulated air bag inflatortest data.

“It’s always troubling when you have a manufacturer who you relyupon to provide truthful information and that information is notprovided,” said Foxx, 44, who didn’t meet with Tokyo- based Takataduring his visit to Japan. “In many cases, what we found wereomissions that were unnecessary and harmed our ability to ensurethe safety of consumers, and in some cases, even errors ofcommission.”

VW testing

Volkswagen last month said it was collecting Takata air bagsfrom its vehicles for testing and told NHTSA that gettingreplacement parts would take more than a year if recalls areexpanded. There are no indications of a defect in its vehicles, andVolkswagen said it isn’t planning a recall, the German carmakerwrote to NHTSA in a letter dated Oct. 15.

In separate letters, Daimler’s Mercedes-Benz unit and JaguarLand Rover told NHTSA that they’re not testing air bags in theirvehicles or planning recalls. Tesla’s letter was made public butredacted and cited confidential business information.

Spartan Motors Inc., a maker of fire trucks, said in its letterthe company hadn’t been made aware that it should be included inthe recalls. NHTSA had sent letters to the companies in Septemberinquiring about their use of Takata air bags with ammonium nitratepropellant.

Takata’s viability

The “coordinated remedy order” released by NHTSA last weekdivides the vehicles already involved in Takata’s recalls intopriority groups, with the deadline for the first set of vehicles tobe repaired by March 2016. Others begin in 2017 and run through2019.

Takata President Shigehisa Takada last week told reporters thecompany was considering survival plans, which weren’t at the stagehe could discuss. The supplier has hired SMBC Nikko Securities Inc.to draw up a fundraising plan for the air-bag supplier, with thefinancial adviser proposing an additional share sale as one of thepotential options, according to people familiar with thematter.

“There have been some commitments made by Takata to clean thissituation up,” Foxx said, when asked whether he had concerns aboutthe company’s viability. “We’re expecting them to carry through onthose commitments. We will continue working with them to get thissituation back under control and in a place where we can expect ourconsumers to be safe.”

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