WASHINGTON — The U.S. government appears poised to order a recall of millions of air bag inflators due to a manufacturing flaw that could send metal shrapnel rocketing through a car interior. The National Highway Traffic Safety Administration held a public hearing Thursday on air bags made by ARC Automotive of Tennessee.

At least 25 million vehicles containing ARC-made air bags could be affected. ARC has refused to issue a full-scale recall, setting the stage for the possible court fight. Thursday’s hearing was one of the final steps before the agency can issue a formal recall order and take the case to court for enforcement.

The company maintains that no safety defect exists.