This 2014 Ford Mustang is one of almost 34 million vehicles recalled in the United States for defective airbags made by the Takata Corp. Source: Ford Motor Co.

More than 30 million vehicles in the United States have been recalled in recent months because of defective airbags. 

The defective airbags were made by Japan-based supplier Takata Corp. (NASDAQ: TKTDY) for many different automakers. The issue is that the airbags' propellant can deteriorate in a way that causes the bags to spray metal shards around the car's cabin when set off in an accident. 

Over 100 injuries, including six fatalities, have been linked to the defective airbags so far. As its investigation has progressed, the Department of Transportation has expanded the list of cars that need to be recalled in the U.S. to almost 34 million. Millions more are being recalled in other countries.

This is a huge, expensive project. How is it affecting Ford (NYSE:F) and other major automakers?

Ford's exposure is significant -- but not bad in comparison to rivals
The good news for Ford shareholders is that the company hasn't been hit nearly as hard as some of its rivals. 

As of May 28, Ford had recalled 1,509,535 vehicles in order to replace potentially defective Takata airbags. The list includes 2005-2014 Ford Mustangs, 2005-2006 Ford GTs, 2004 Ford Rangers built at the Edison Assembly Plant in New Jersey (now closed), and 2004-2006 Ford Rangers built at the Twin Cities Assembly Plant in Minnesota (also now closed).

Ford said in a statement last week that it is aware of just one incident involving a defective airbag in one of its vehicles, in which a metal fragment injured a driver's leg when the airbag deployed after a crash. The metal fragments come from the airbag's inflator, which can rupture. Ford said it has so far not seen any other inflator ruptures in its vehicles, either in testing or in reports from the field.

Ford's obligation here is to pay to have those defective airbags replaced. It must notify owners of the affected cars and trucks, make sure its dealers have adequate supplies of replacement airbag parts, and track everything so it knows which cars have (and haven't) been fixed. It won't be cheap, but the costs should be covered by the "warranty reserve" that Ford holds on its balance sheet for such events. (Ford expanded that reserve last year, in the wake of rival General Motors(NYSE:GM) massive series of recalls.) Eventually, Ford should (theoretically, at least) recover some or all of the costs from Takata. 

Those 1.5 million vehicles might sound like a lot for Ford to fix, and it is. But it's a relatively small total compared to what some of Ford's rivals are facing, and the huge numbers involved mean it could be a while before all of those cars and trucks get new airbags.

Millions of Hondas and Toyotas must have their airbags replaced
We don't yet know the specifics of all of the cars to be recalled. The Department of Transportation greatly expanded the list of involved airbags last week, and automakers have been scrambling to identify the affected cars and notify owners. 

But we do know that Honda (NYSE:HMC), which most reports say is the hardest-hit automaker in this situation, has already recalled well over 5 million vehicles in the U.S., and millions more abroad. Toyota (NYSE:TM), Nissan (OTC:NSANY), and Fiat Chrysler Automobiles (NYSE:FCAU) have also had to recall significant numbers of vehicles. Models made by BMW, Mazda, Daimler's truck unit, and Subaru are also being recalled for the defective airbags. 

But it could take a year or more to repair all of the affected cars and trucks. That's because Takata and its airbag-making rivals need time to make enough replacement airbag parts to go around. Takata itself can only make about 450,000 a month, according to an Automotive News report. Its biggest rival, Autoliv (NYSE:ALV), has committed to provide 25 million replacement airbag inflators to various automakers -- but the last of those won't be delivered until sometime next year.

The upshot: Not a big deal for investors, but get your car fixed if it's affected
The impact on most of the affected automakers should be minor from an investment perspective. But it's still a significant situation that should be watched closely.

Meanwhile, if your car needs to be recalled, don't lose sleep over it -- but do get it fixed as soon as you can. While the individual risk is extremely small, the consequences of a defective airbag are pretty horrible.

The National Highway Traffic Safety Administration maintains an online tool that you can use to find out if your car has been recalled. To use it, you'll need your car's Vehicle Identification Number. 

Note that it could be a few weeks before all of the cars affected by the latest rounds of Takata-related recalls are entered into the NHTSA database. If you think your car might be affected, keep checking back.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.