CAR SEATS EXPIRE!
Plastic degrades over time, especially when exposed to the elements. Imagine that plastic play set you probably have in your back yard. Left in the son for six years, it starts to get brittle, and it starts to break. Car seats aren't much different. We leave them in our cars where they end up baking in the 130 degree heat, or freezing in the -40 degree cold. They are designed to withstand this abuse, for sure, but not forever. The plastic deteriorates, cracks, and breaks. The foam padding, after being compressed for ages, does the same thing. I'll be honest and say that I have a hard time with the idea that the nylon harness also expires, but if you're buying a new seat anyways, why would you reuse the harness?
Most seats expire six years after the date they were made, NOT six years after you bought them. While normally you will get a new car seat close to when it was made, it doesn't always happen. If you bought it on sale, for instance, it may have been marked down due to an early manufacture date. You have to check the seat for a date of expiration or a date of manufacture. Generally speaking, both are on the seat somewhere, usually on the bottom, or one of the side stickers. Sometimes you find a month, a day, and a year, and sometimes you'll only find month year. Graco is the only company where the seats expire at the end of the sixth year. All other seats expire in the month they were manufactures (so my kid's Evenflo Tribute - pictures here - will expire in July 2014).
Sure, it's highly unlikely that your seat is going to magically disintegrate on the first day of the sixth year. Here's a video showing what happens when a ten year old car seat is used during a crash. The shell has degraded so much that the harness, while securely holding the child, rips through the plastic shell. It doesn't state the injuries sustained by the "child" in this case, but I think it's pretty obvious that this is not a good outcome:
Yeah, this was ten years after, not one year after. But without knowing exactly when the car seat went from a safe condition to this condition, it's just a better choice all around to believe the manufacturer. I, too, wish they would publish this kind of information, or do more tests, or at least give us a CLEAR reason why the seats expire except "they might be broken." but alas, this is all we have to work with right now.
Not all seats expire after six years, so here's a useful list.
Baby Trend: 6 years
Britax classic generation: 6 years
Britac new generation: 7 yearsYears for most
Britax Frontier specifically: 9 years
Chicco: 6 years
Clek: 7 years
Clek Foonf specifically: 9 years
Compass: 7 years
Cosco: 6 years
Combi: 7 years
Evenflo: 6 years
Graco: 6 years (December of the 6th year) for most
Graco Nautilus specifically: 10 years
Harmony: 6 years
Maxi Cosi: 6-8 years
Orbit: 7 years
Peg-Perego: 5 years
Seats manufactured starting 2011: 7 years
Recaro: 6 years
Safety First: 6 years for most
Safety First Complete Air specifically: 8 years
Safety First Alpha Omega Elite specifically: 8 years
Sunshine Kids: 6 years for most
Sunshine Kids Monteray: 8 years
Diono seats: 10 years
The First Years: 7 years
If your brand of seat isn't on this list, and you can't find an expiration date or a date of manufacture, please don't hesitate to post a comment asking, and I will find the information for you. =)
Keep your kids safe!