Installing and Using Child Safety Seats and Booster Seats


Proper restraints for children riding in motor vehicles depend on the child's age and size. Restraints to keep a child safe in the car include:

  • Infant safety seats

  • Child safety seats

  • Child booster seats

  • Properly used safety belts

The key to keeping your child safe is to use an age-appropriate child restraint that is properly installed and properly used.

Infant and child safety seats come in many shapes and sizes. Some are not compatible with certain vehicles. The best child safety seat for a family is the one that is easy to use for the parents or caregivers, fits in the vehicle's seats, is compatible with the vehicle's seat belts, and is the proper size for the child. The American Academy of Pediatrics has a series of specific recommendations for the use of child safety seats:

  • Children should face the rear of the vehicle until they are at least 2 years of age or preferably until they reach the maximum height or weight allowed by the seat. This is to reduce the risk of cervical spine injury in the event of a crash. Infants who outgrow their car safety seat recommended by the manufacturer can use convertible seats, but must still be rear-facing.

  • A rear-facing car safety seat must not be placed in the front passenger seat of any vehicle equipped with a passenger-side front air bag. This practice prevents the risk of death or serious injury from impact of the air bag against the safety seat.

  • Premature and small infants should not be placed in car safety seats with shields, abdominal pads, or arm rests that could directly contact an infant's face and neck during an impact.

  • In rear-facing car safety seats for infants, shoulder straps must be in the lowest slots until the infant's shoulders are above the slots. The harness must be snug and the car safety seat's retainer clip should be positioned at the midpoint of the infant's chest, not on the abdomen or in the neck area.

  • The car safety seat should be reclined halfway back, at a 45-degree tilt. A higher angle should be used when the child is over 6 months. Until engineering modifications can be put into place to prevent this problem, a firm roll of cloth or newspaper can be wedged under the car safety seat below the infant's feet to achieve this angle.

  • A convertible safety seat should be used as long as the child fits well. (This includes ears below the top of the back of the seat and shoulders below the seat strap slots.) It is positioned reclined and rear-facing for a child until 2 years of age and semi-upright and forward-facing for a child older than 2 years of age who weighs 20 to 40 pounds,

  • A booster seat should be used when the child has outgrown a convertible safety seat, but is too small to fit properly in a vehicle safety belt.

  • A belt-positioning booster seat that uses a combination lap/shoulder belt, if that type of belt is recommended. A booster seat with a small shield, which can be used when only a lap belt is available, is not recommended by the National Highway Traffic Safety Administration (NHTSA).

The infant safety seat

Infant safety seats are often small and portable seats used for babies up to age 1 and 35 pounds. Infant seats are rear-facing and may come with a three-point or a five-point harness. Some infant seats come with detachable bases that can be left belted into the vehicle so that the parent does not have to install the seat every time. (Some bases also are adjustable to correctly recline the infant.)

The child safety seat

Child safety seats are either convertible seats or forward-facing seats:

  • Convertible seats can be used for infants up to age 2 in the rear-facing position, and then turned around into the forward-facing position for toddlers. The disadvantage of a convertible seat is that it does not fit a newborn as well as an infant safety seat. When changing from a rear-facing position to a forward-facing position, parents or caregivers should check the seat's manual on how to adjust the shoulder straps appropriately and how to position the seat belt properly.

  • Forward-facing child safety seats are for children over 2 years of age. Some seats may convert to booster seats for children over 40 pounds.

The booster seat

Booster seats help raise your child so that the vehicle's seat belts fit properly. Booster seats are necessary when a child outgrows his or her child safety seat top weight or height, usually after 40 pounds or age 4. Children do not fit in adult shoulder/lap belts (without a booster seat) until they are 58 inches tall (with a sitting height of 29 inches) and weigh 80 pounds, according to the CDC.

Booster seats should always be placed in the back seat of the vehicle. There are two types of booster seats:

  • High back booster. A booster seat that helps protect the head and neck in back seats that do not have head restraints. The vehicle's lap and shoulder belts are used to secure the child. 

  • Backless booster. A booster seat that raises the child up so that the vehicle's lap and shoulder belts properly restrain the child.

Checking your car seat

As many as 73% of child safety seats are found to be improperly installed and/or used, according to the National Highway Traffic Safety Administration. Some of the most common mistakes in installing or using child safety seats include the following:

  • Safety belt not holding the seat in tightly or not in locked mode

  • Harness straps not snug or positioned correctly

  • Harness retainer clip not at armpit level

  • Locking clip not used correctly

  • Car seat recalled and not repaired (includes booster seats)

  • Infants placed rear-facing in front of an active air bag

  • Children turned forward-facing before reaching 2 years of age

Parents and caregivers should carefully read their vehicle owner's manual and the instructions that come with the child safety seat to make sure of proper installation and use of the seat. The NHTSA recommends doing the following quick safety seat assessment:

  • Is your child riding in the back seat? (The back seat is the safest place in a crash.)

  • Is your child facing the correct way? (Infants up to age 2 should face the rear.)

  • Is the child safety seat held tightly in place by the seat belt?

  • Does the harness buckle snugly around your child?

  • If your child is between 40 and 80 pounds, is he or she in a booster seat for better seat belt fit?

  • Does your older child fit properly in the vehicle's seat belts? (The shoulder belt should rest over the shoulder and across the chest, and the lap belt should fit low and tight over the upper thighs. The child should be tall enough to sit with knees bent at the edge of the seat--at least 58 inches tall and 80 pounds.)

Replacing child safety seats and seat belts after a crash

Once a vehicle has been in a severe crash, child safety seats and seat belts should be replaced because they may have become stretched or damaged. All child safety seats are replaced by insurance companies. Always check with your child safety seat manufacturer concerning questions about the safety of your child's seat.

When car seats are recalled

Sometimes child safety seats are recalled for safety reasons. It is important to register your car seat to make sure that you are notified if the specific product is recalled. To check if your child safety seat has been recalled, call the seat's manufacturer or the National Highway Traffic Safety Administration Vehicle Safety Hotline at 888-327-4236. If the seat has been recalled, you will be instructed on how to repair it, or how to obtain parts to repair it.