Nearly a month after the National Highway Traffic Safety Administration urged automakers and parts manufacturer Takata to expand recalls of vehicles with airbags that may spew shrapnel at passengers upon deployment, Honda and Mazda have agreed to national recalls – although many specifics regarding the new recalls remain undetermined.

Reuters reports that Takata’s biggest customer Honda, which has been linked to four of the five deaths involving the airbags, will voluntarily expand its previous regional recall to include an additional 2.6 million vehicles in the United States and 134,000 cars in the Japan.

A spokesperson for Honda tells Reuters that the company is still determining which models would be covered under the national recall.

The expansion brings the total number of Hondas recalled for the issue to 5.4 million vehicles in the U.S.

Previous Honda recalls only covered vehicles registered in hot, humid areas of the U.S. including Puerto Rico, Hawaii, the U.S. Virgin Islands, Guam, Saipan, American Samoa, Florida and adjacent counties in southern Georgia, as well as the coastal areas of Alabama, Louisiana, Mississippi and Texas.

As for Mazda, a spokesperson tells Reuters that the company will expand its current regional recalls nationally, but has yet to determine what models and how many vehicles are included in the new initiative. Previously, Mazda recalled 86,773 vehicles for the airbag issue.

Honda and Mazda’s newly announced initiatives bring the total number of vehicles recalled for the Takata airbag defect to 13 million in the U.S. and 19 million globally.

The airbags have been the center of controversy since early summer when car makers began recalling vehicles after receiving reports that drivers and passengers were hit with flying pieces of metal when their airbags deployed.

The airbag issues led to a number of investigations by NHTSA. One centers on Takata’s processes and the production of the airbag.

Additionally, NHTSA opened an investigation into Honda’s reporting procedures after it was revealed the company didn’t properly notify regulators about issues related to the Takata airbags. The car company currently faces the possibility of a record-breaking $35 million fine for its reporting failures.

In mid-November, NHSTA urged car manufacturers and Takata to issue nationwide recalls for the defective airbags.

Officials with the agency say the decision to call for an expanded recall was based on NHTSA’s evaluation of a recent driver’s side airbag failure in a vehicle outside the current regional recall area. The incident involved a 2007 Ford Mustang in North Carolina.

Investigators with NHTSA say that all other incidents of Takata airbag ruptures have occurred in areas of the regional recall.

Shortly after NHTSA’s request, officials with Takata said during a congressional hearing that they wouldn’t initiate a national recall, in part because they don’t believe that NHTSA has the power to order such an initiative and because testing hasn’t shown what’s really behind the issue.

It was previously reported that Takata uses an unusual chemical explosive – ammonium nitrate – for the chemical’s ability to make airbags inflate in a matter of milliseconds. Since then the company notified NHTSA of a change in its chemical compound.

Honda, Mazda to expand investigative air bag recall [Reuters]

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