(HealthDay News) -- When children reach about 40 pounds, it's probably time for them to graduate from an infant car seat to a booster seat.

The Nemours Foundation offers these suggestions about booster seats:

• A booster seat should be placed in the back seat, facing forward and preferably in the middle seat, secured with both a lap and shoulder belt.
• Always read the manual on how to install and fasten a booster seat. Also read the manual for your car, which may explain how its seat belts work with a booster seat.
• Make sure the booster seat is safely and tightly secured before each trip.
• Adjust the lap belt so that it fits low and snug across your child's lap, and the shoulder belt is snug across the shoulder. The shoulder belt should not interfere with the neck or face.
• Always keep shoulder belts flat against your child, and never allow them to twist.