Yes, car seats do expire. In fact, most car seats have an expiration date on one of the manufacturer labels that can be found on the sides or bottom of the car seat. To find out if a car seat is expired, you should look for that expiration date label first. If there's no expiration date listed, use the date of manufacture and consult the car seat owners' manual. Many manufacturers give a maximum car seat life in the manual. If not, call the manufacturer and ask. The rule of thumb, if no expiration date is given on the seat, is that car seats expire six years from the date of manufacture. Assuming that your car seat was manufactured in 1999, when you purchased it, yes, it is expired. A few car seat manufacturers allow 10 years of life for their car seats, but unless you have specific directions from the manufacturer, the car seat label or the manual that state otherwise, you should stop using a car seat after 6 years. Expired car seats should be destroyed so that no one picks the seat up thinking that it is still safe to use. Good ways to destroy car seats include cutting up the cover, cutting the harness straps, and using a saw or large hammer to break the shell. If you can actually watch the car seat go into a garbage truck and watch it be crushed, this is a good option, too. While I can understand the frustration of throwing away something that still looks good, it's important to understand that the breakdown of a car seat is not something that can always be seen with the naked eye. Car seats are made of plastics. Consider what happens to a plastic toy if it is left outside for some time. The plastic becomes brittle and can develop cracks when stressed. Car seats are subjected to extreme heat and extreme cold while sitting in your vehicle, so the plastics eventually react just like that toy left in the sun. You may not be able to see that the plastic is breaking down, or is more brittle, but that change could be dangerous in a crash when the car seat shell is stressed. It's far safer for parents to buy a new car seat than to take a chance on a car seat that may be too old to function properly in a crash.
Heather Corley is a certified Child Passenger Safety Technician.
http://babyproducts.about.com/b/2006/07/12/reader-question-do-car-seats-expire.htm I included the website this article is from so you can read some of the comments.
These are a few other sites to visit:
This video is a crash test with an expired car seat:
I just googled the subject, do car seats expire and I found lots of information but these are the best articles. I also found out another interesting fact that if you are in a car accident you need to destroy your car seats. They say you can't tell if the plastic that is not visible is cracked, so why chance it. Take it or leave it but I know my children are worth it. I have seen car seats for $50 these days. So beware of garage sales, resale shops, flea markets and other places to buy used car seats. Also watch buying car seats on sale b/c you may only get 3 years out of it.