Back when I owned an '88 Mercedes there were words that airbag life was 15 years, at which time they were to be replaced.
Basically, I think, this has been quietly forgotten as it's the equivalent of politically incorrect to tell someone it's time to spend $800 or whatever it is for a new airbag on their 15 year old car. Be sure to wear your seatbelt.
As an aside, rolamite switch technology has been used in airbags, the rolamite being invented at my former employer. Link doesn't mention, but I think he was inspired by those toilet paper containers seen in commercial locations.
https://en.wikipedia.org/wiki/Rolamite
Hybrid Mode
