Yes, regarding the time in years.
Here is one study.
https://www.motorcyclemanic.com/you-need-to-know-now-what-is-a-motorcycle-helmets-lifespan/And here is another opinion.
https://forums.mtbr.com/apparel-protection/helmet-lifespan-time-dispell-myth-792859.htmlIn this litigious society, the helmet manufactures must put a life span on the helmets.
In my search, I did not find any definitive tests that would indicate that older helmets were actually tested to see how they did or did not deteriorate.
I did purchase a new helmet, again a Shark Evoline, the same size as the one I had, several years ago (two or three). It was he same size as the one I was using but, after using it for a few months, I gave it to my wife, and returned to my original Shark.
I like the Shark Evoline helmets. they are versatile but heavy.