(May 5, 2016, 1:27 PM EDT) -- WASHINGTON D.C. — The U.S. Department of Transportation’s National Highway Traffic Safety Administration (NHTSA) on May 4 expanded the recall of Takata air bag inflators by an additional 35 million to 40 million, after confirming that the root cause of the inflators’ propensity to rupture is linked to the degradation of ammonium nitrate propellant after it is exposed to humidity and moisture. The expansion brings the total of Takata air bags recalled to 68.8 million....