?? Expiration dates on car seats

I was just curious if anyone knew why car seats have expiration dates?  Is it just because they change the safety rules?  Or is there some other reason....
Just curious is all...Thanks!

This was taken from http://www.carseat.org

How old is too old for a safety seat?

There is some controversy about the "expiration" date for safety seats. All experts agree that a seat should be discarded and destroyed if it is more than 10 years old, even if it looks fine. Most manufacturers suggest replacing a seat 5 to 8 years after the date of manufacture, because current safety seats may have better safety features than older seats, such as a tether or air bag warnings. The date of manufacture may be found on a sticker on the seat (unless it has peeled off) and may be stamped into the plastic shell. However, don’t confuse patent dates, which can also be molded into the plastic, with the date the individual safety seat was manufactured. For more information, go to Expiration date.

Thanks fort the info...that is what I was thinking but wasn't quite sure!  It was just a curious question! 

I heard on a commercial that it is because they are often stored in the car or in the garage, and with extreme heat and cold, it can wear down the material.

HTH!

Lisa

Thanks for the reply...I knew it was something like that...That makes sense though!  I was just curious on the theory of it! 

SOOOO funny that u ask this....my husband and i just went to this class {one of the many for childbirthing series} and when they said that CAR SEATS EXPIRE no one asked why but my mom had asked me and i didnt know so next class i ASKED....and the reason is because....the plasitc apparently gets brittle! so after 6 years u are supposed to discard it....and not throw it in the trash....like DIMOLISH it so no one else uses it. yup there is ur answer!! :)

I was thinking it was something like that...Thanks for the info!  I was just curious!  So...why do they put an expiration date on them is you should discard them in 6 years?  Is that just when the manufacturer becomes outdated for that seat as far as safety and then the 6 years is for use because they have been in and out of your car?  Hope that question makes sense...I wasn't sure how to word it like I was thinking!  LOL!   Thanks for the answers!

I've heard disguard after 2 years

Ash :)

Every 2 years?  Wow, that is often...I haven't heard that....so I will have to do some research because if that is true I will be getting the car seat I originally wanted!  Thanks!