Parents are often surprised to hear that car seats have expiration dates. Well, they do, and for good reason. Let's take a look at some of the reasons that car seats expire, and then we'll talk about how to check that your child's car seat is still safe to use.

Reason 1 - Heat, Cold, Sun Can Degrade Plastic
Even if your baby's car seat is never in a crash, it's actually subjected to some pretty harsh conditions daily just by being in the car. The interior of the car gets extremely hot in some parts of the year, and possibly very cold in other parts, depending on where you live. Temperature extremes could affect plastic over time. Sun exposure can also affect plastic. Just like plastic toys get brittle when left outside in the sun, this exposure can weaken the plastic in a car seat, too.

Reason 2 - Car Seat Safety Improvements
Manufacturers use data from studies of real life crashes as well as crash tests to improve the function of car seats over time. What is considered the ultimate in safety engineering one year may later be shown to need improvement, or may be replaced by something that could protect children so much more. Technology in almost any industry changes over time. Computers, MP3 players and cell phones are replaced by newer and better models almost as soon as they leave the factory. But, those items aren't called on to save a child's life in a crash, so replacing them with something newer in a few years isn't vital.

Reason 3 - Missed Recalls
Sometimes car seat manufacturers have to issue recalls to fix safety issues with their car seats. Some of these recalls are widely publicized, but others aren't. Some are confusing if they cover multiple models or manufacture dates. Sometimes, people just don't hear about recalls or realize that the one they just heard on the news applies to the car seat they have in the garage for a future child. Giving car seats an expiration date increases the chance that those car seats that needed repairs will be retired at some point, hopefully before they're ever needed in a crash.

Reason 4 - Time, Kids and Travel
Depending on the type of car seat you purchased, after five or six years, the cover may be shredded, the straps may twist into impossibly difficult ropes, the foam padding may be full of mysterious kiddie substances and you may not even want to look at the seat, let alone put your child in it. I've seen some seats that survived the full useful life looking good, but kids are very hard on car seats, so most of them show it after a while. For traveling families, your car seats also may have been hauled in and out of the car more than most, which could mean it has been dropped a time or two. If you've checked it at the airport, it was tossed into the plane with the other luggage. Those extra bumps add up over time, and could create weak spots in the car seat.

What Can Happen If I Use An Expired Car Seat?
Car seats, though they are used daily, are really single use items. Your child really only needs one in the moment that a crash happens. So, you need your child's car seat to be in good enough shape to work properly for that one time. The best illustration of what can happen with an expired car seat is this crash test video, which shows an expired ten-year-old Britax car seat. http://www.youtube.com/watch?v=wvCRz7BRAM0

How To Check Your Car Seat for an Expiration Date
All car seat manufacturers are required to put the date of manufacture somewhere on the car seat. Sometimes it's on a sticker on the side. Other times you may have to take the car seat out of your vehicle and turn it over to find the sticker on the back or bottom Some manufacturers even mark an expiration date on the car seat along with the date of manufacture. If an expiration date isn't listed, you can check the car seat manual to see if it says how many years the car seat is safe to use. If you can't find the information in the manual, call the manufacturer. A general rule of thumb is 6 years from the date of manufacture, but some companies vary from that, so it's a good idea to check. It's important to note that the expiration date doesn't depend on how much time the car seat has spent actually being used. It's always from the date of manufacture.

When the Car Seat Expires
Before getting rid of an expired car seat, take a moment to cut the straps or otherwise damage it so that it's obvious to any would-be curbside bargain hunters that it is not useable.