Takata Corp. is investigating excessive moisture as a possible cause of defective airbag inflators that have led to 5.9 million recalls globally this year and last.
Today’s announcement by one of the world’s biggest airbag suppliers echoes the suspicions of U.S. safety regulators. On June 11, the National Highway Traffic Safety Administration said high humidity in Florida and Puerto Rico may have played a role in six incidents of ruptured frontal airbags.
The agency now is investigating potentially defective inflators in vehicles produced from model year 2002 through 2006 by Toyota, Nissan, Honda, Mazda and Chrysler.
In a statement, Takata CEO Shigehisa Takada confirmed that the inflators may have been damaged by moisture.
“We currently believe the high levels of absolute humidity in those states [Florida, Puerto Rico] are important factors; and as a result our engineers are analyzing the impact that humidity may have on the potential for an inflator malfunction,” he said.
Moisture can cause the propellant to crumble, so that it burns too quickly when ignited, Reuters reported in January. That, in turn, can cause the inflator to explode, spraying pieces of metal into the cabin.
According to Reuters, two motorists were killed in separate incidents in 2009 by metal pieces of the inflators after they exploded. But in the six incidents currently under investigation by NHTSA, nobody was seriously injured.
After the June 11 NHTSA announcement, Toyota said it would recall 2.3 million vehicles worldwide. In 2013, Honda, Toyota, Nissan, BMW and Mazda recalled 3.6 million vehicles with Takata inflators, according to Reuters.
Honda is poised to recall as many as 1 million vehicles this month for the same issue, Reuters reported this week, citing a source.
Damaged by moisture
Takata’s statement indicates that moisture on the road, in addition to moisture at the factory, can degrade the inflators.
Three companies -- Japan’s Takata, Sweden’s Autoliv Inc. and TRW Automotive Inc. of the United States -- dominate the global safety – systems business.
In part to combat moisture, they have located their inflator plants in arid regions.
TRW makes inflators in Mesa, Ariz., while Autoliv has a plant in Brigham City, Utah. Takata’s inflator plants are in Moses Lake, Wash., and Monclova, Mexico.
Deserts are considered ideal locations for inflator plants because their remote location limits the damage in case of explosions. Equally important, the dry air makes it easier to shield the inflator’s propellant from moisture.
It was moisture that caused some of Takata’s inflators to malfunction, according to the Reuters report in January.
Ammonium nitrate, the propellant used in Takata’s inflators, is sensitive to moisture, according to Reuters. The moisture can cause the wafers of propellant to crumble, so that it will burn too fast when ignited. When the airbag deploys that can trigger an explosion.
From 2000 to 2002, Takata’s plants in Washington and Mexico used some propellant that had been exposed to moisture. Takata fixed the problem at the factory, but faulty record-keeping hampered it from identifying those batches. So the automakers issued huge recalls to track down all defective airbags.
Last year, Autoliv’s sales of airbags and seat belts totaled $8.5 billion, while Takata reported sales of $3.9 billion for the 2014 fiscal year that ended March 31. The third largest supplier, TRW Automotive, recorded $3.4 billion in sales of occupant safety systems last year. The data are from the companies’ annual reports.
Other major suppliers include Key Safety Systems -- which had global sales of $1.2 billion -- and Toyoda Gosei Co.
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