Auto parts supplier Takata Corp. slashed its annual earnings forecast on Friday, saying it had yet to determine the full impact of a global safety recall as customers began ditching its air bag inflators.

U.S. auto safety regulators earlier this week linked Takata's failing inflators to the use of ammonium nitrate as a propellant, prompting automakers from top customer Honda Motor Co. to Mazda Motor Corp. to say they will no longer fit the product in new cars, fanning concerns over Takata's future.

On Friday, Toyota Motor Corp. said it, too, would stop using Takata inflators containing ammonium nitrate, which U.S. regulators believe can cause air bags to explode with excessive force, spraying shrapnel inside the vehicle. Regulators have linked them to eight deaths, all in Honda cars, triggering the recall of tens of millions of vehicles worldwide.