(Adds details, comments from ARC and Kia)
By Sagarika Jaisinghani
July 14 (Reuters) - U.S. safety regulators said they were investigating airbag inflators made by ARC Automotive Inc for rupture, the second company to be probed for defective airbags after Japan's Takata Corp.
The ARC probe will cover airbags in about 420,000 Fiat Chrysler Town and Country minivans from model year 2002, and 70,000 Kia Optima midsize sedans from model year 2004, the National Highway Traffic Safety Administration (NHTSA) said in documents posted on its website on Tuesday. (1.usa.gov/L6b9wg)
"We have received NHTSA's notification and are cooperating fully with its preliminary evaluation," ARC spokesman Will Edgar said in an email to Reuters.
ARC makes inflators used by other auto parts makers in airbag modules that are then sold to carmakers.
The ARC investigation comes nearly two months after Takata doubled a recall of potentially deadly airbags to nearly 34 million vehicles, making it the largest automotive recall in American history.
The NHTSA said it received two complaints involving ARC inflators, the first in December about a 2009 incident in a Chrysler minivan and the second in June in a Kia vehicle.
A preliminary analysis of the inflator used in the Chrysler minivan showed that the exhaust path for the inflation gas mixture might have been blocked "by an object of indeterminate origin," the NHTSA said.
"This blockage appears to have caused high internal pressure and subsequent rupture of the inflator assembly."
Fiat Chrysler and Kia said they were no longer using the inflators that are being investigated.
The NHTSA said there were two known injuries related to the incidents, but no known fatalities.
"At the present time it is unknown if there is a common root cause in these incidents," the NHTSA said.
"(The agency) is opening this investigation in order to collect all known facts from the involved suppliers and vehicle manufacturers."
The NHTSA said the ARC inflators in question used an ammonium nitrate-based propellant, the compound seen as a contributing factor to Takata's faulty airbags, although the Japanese company has defended it.
ARC declined comment on whether ammonium-nitrate was used in the inflators being investigated. (Additional reporting by Ankit Ajmera in Bengaluru and Paul Lienert in Detroit; Editing by Sriraj Kalluvila)