Japanese car parts company Takata on Tuesday recalled another 2.7 million air bags that it previously thought were safe.
The recall affects certain Ford, Mazda and Nissan cars from the 2005 through 2012 model years.
Takata's air bags are inflated by a chemical — ammonium nitrate — in emergency situations, but it can deteriorate in conditions of high humidity and heat. The company added a desiccant to stop the chemical inflators from degrading and thought they had then been made safe.
However, tests by the U.S. National Transportation Safety Board showed that Takata air bags were still subject to inflating without warning, expanding with great force and sending metal parts flying. Previous problems with Takata air bags have killed at least 17 people and injured more than 180.
Takata, which has filed for bankruptcy protection, has already recalled 42 million cars to replace the defective inflators, the largest automobile-related recall in U.S. history. But the latest recall raised doubts about the safety of other Takata inflators. The company has agreed to recall all original equipment inflators without a drying agent in phases by the end of 2018. The National Highway Traffic Safety Administration gave Takata until the end of 2019 to prove that inflators with the drying agents are safe, or they must be recalled as well.
U.S. Senator Bill Nelson, a Florida Democrat, said federal regulators have to act faster to determine whether all Takata air bag inflators are safe.
"We certainly can't afford to wait until the December 2019 deadline. ... If even more are found to be defective, it will take us from being the biggest recall ever to something that could become mind-boggling," Nelson said.