More than 200,000 Irish car owners are driving cars where airbags are approaching the 10-year-old mark, where many manufacturers suggest they be replaced.
However, there's no evidence that owners of cars in the relevant bracket ever think of doing that. The cost of a replacement airbag averages €350 per unit.
The National Car Test (NCT) agency says they have no way of checking whether an airbag is in safe condition.
"The only thing we can fail a car on in this respect is if the airbag warning light is on," a spokesman told The Irish Times yesterday.
But such warning lights go on in brand-new cars on a regular basis, and are simply reset. "There's only one way to check if an airbag is working, and that's to deploy it," a technical manager for one car company says.
Studies suggest that airbags increase a seatbelt-wearing occupant's survival rate by just 9 per cent. This is on top of the 42 per cent increase in survival ratings between occupants with or without seatbelts.
The issue with airbags is particularly relevant for those with older cars, where age and unexpected problems might begin to show up in inadvertant deployment of the supplementary restraint systems.
However, it's not just in older cars that problems with airbags have arisen. Mazda in the US, for example, recalled 42,000 of their 2004 Mazda3 models late last year because water seepage into the airbag housing potentially made the bags liable to failure in an accident.
On the other hand, the US National Highway Traffic Safety Administration is investigating 117 incidents of spontaneous airbag deployment in recent-year Volkswagen cars, which resulted in a reported 19 injuries.
In the two years between 1997 and 1999, some three million cars were recalled in the US because of potential airbag problems, including over 100,000 Cadillacs because their bags could deploy without any impact.
Worldwide recalls for airbag problems in that same period included Audi, Volkswagen, Renault, Honda, Opel, Volvo, Mercedes, Saab and BMW cars.
The more recent recalls and investigations suggest that the arrival of more sophisticated airbag systems don't necessarily mean they are less likely to cause problems.