The problem of exploding air bags could be widening beyond Japanese manufacturer Takata Corp.
U.S. safety regulators are investigating inflators made by ARC Automotive Inc. that went into about 420,000 older Fiat Chrysler Town and Country minivans and another 70,000 Kia Optima midsize sedans.
The probe, revealed in documents posted Tuesday by the National Highway Traffic Safety Administration, comes just weeks after Takata agreed to recall 33.8 million inflators in the U.S. in the largest automotive recall in American history. At least eight people have been killed worldwide by flying shrapnel from Takata inflators, and more than 100 injured.
The safety agency said it received a complaint in December about a 2009 incident in a 2002 Chrysler minivan but determined it was an isolated case involving an ARC driver's side inflator. Then in June, Kia told the agency about a lawsuit involving a 2004 Optima in New Mexico with an ARC driver's side inflator, so the agency decided to open an investigation. Both cases are the only known incidents involving ARC inflators in vehicles made by either automaker.
The agency said two people were hurt in the incidents but no one was killed.
Knoxville, Tennessee-based ARC said in a statement that it is cooperating in the probe and pointed to a 60-year record of "serving our customers with products that meet the most stringent global safety standards.''
Fiat Chrysler said it no longer uses the inflators that are being investigated. Both it and Kia said they are cooperating.
NHTSA said in documents that ARC makes inflators that are used by other companies in their air bag systems. The inflators use an inert gas to fill the air bag which is supplemented by an ammonium nitrate-based propellant. A preliminary analysis of the Chrysler minivan system showed that the path for the inflator gas to exit the inflator may have been blocked by an unknown object, the document said.
In the Takata cases, ammonium nitrate is the main propellant, and it can become unstable over time when exposed to high humidity and temperatures. The chemical can burn too fast and blow apart a metal inflator canister. Automakers, NHTSA and Takata are trying to find exactly what causes the malfunctions.
"We have opened up an investigation, to look to see if there is any connection,'' NHTSA Administrator Mark Rosekind told reporters in Orlando, Florida, on Tuesday.
In the Chrysler case, a probable cause was identified, but investigators don't know the cause of the Kia rupture, he said. If the investigation determines that the inflators are a hazard, NHTSA will act, Rosekind said.
"If we find out there is a problem, there could be a recall coming, yes,'' he said.
The investigation will determine just how many of the suspect ARC inflators are on the road, NHTSA said.
Documents show that the Chrysler minivan incident happened on Jan. 29, 2009, in Ohio. A man complained to NHTSA that his wife was injured by flying shrapnel when the minivan collided with a snowmobile while she was turning into their driveway and the air bag deployed.
"Most of the shrapnel went into her chest, with the air bag plate breaking apart, striking her in the chin, breaking her jaw in three places,'' wrote the man, who was not identified. "If it hadn't been for a great ambulance crew, she would have bled to death.''
According to NHTSA, ARC made inflators for Delphi Corp. air bags that were sold to Kia and used in Optimas, and it made inflators for Key Safety Systems air bags sold to Chrysler and used in minivans.
Delphi said in a statement that it will respond to any NHTSA inquiries. ARC inflators were used in some of its air bag assemblies before the company sold its air bag business in 2010, the statement said. Key said it would support the investigation.
Also Tuesday, Rosekind said about three-quarters of the Takata air bags that have ruptured in testing came from Florida. He urged Florida residents whose vehicles have been recalled to get them repaired as soon as possible. High heat and humidity, especially in areas along the Gulf Coast, can cause the Takata air bags to malfunction.
Dealers representing the 11 automakers involved in the Takata recalls have an abundant supply of replacement inflators in Florida, Rosekind said. But if a dealer doesn't have the parts, people should demand a loaner car, he said.
The inflators have ruptured on about 300 of the 30,000 Takata air bags tested in the investigation, NHTSA said.