Parents should keep in mind that car seats won't last forever.

Pennsylvania State Trooper Shannon Yorke, a certified car seat technician, said the life span of a child's car seat is about six years because the plastic can break down and become brittle and may not withstand a crash."When you think about it, the seat is in extreme weather conditions, such as really cold during winter and really hot in the summer," she said."The plastic is constantly going through changes as far as weather, so after a certain period of time it isn't reliable anymore."Once it is past the expiration date, Yorke said parents should destroy the seat before throwing it away."Cut out the padding and harness, and if you have a sledgehammer, smash it so if anyone walking by sees it, they can't take it and use it."Yorke also said it is important to know the history of the car seat as well, so purchasing secondhand seats is not recommended.This is because the seat is typically made to withstand one crash, but there are some exceptions."The rule from the National Highway Traffic Safety Administration is that if a vehicle is involved in a crash, as long as there are no injuries, the vehicle can be driven from the scene, the airbags did not deploy and the side closest to the car seat was not impacted, then you can reuse the seat," she said."But, if there are injuries, the airbags go off, the door closest to the seat is damaged or the vehicle can't be driven from the scene, then we recommend you replace the seat."This is because the integrity of the plastic on the seat may have been damaged even though it could not be seen."With a crash, there are things going on you may not realize so you may not see it but there could be stresses put on the seat and if it is in another crash it may not hold up," Yorke said.If a seat needs to be replaced because of a crash, check with your insurance provider because they may pay for a replacement seat.