Which safety seat is "the best" for my child?  

by SafetyBeltSafe U.S.A.

The short answer:  The "best" child safety seat is the one that fits your child, fits your car, and fits your family's needs in terms of comfort and convenience, so that you'll use it on every single ride. Try before you buy! For the long answer — read on.

How can I tell which safety seat fits my child?

Consider both the age and the size of your child. Follow these general rules:

   • Keep babies rear facing as long as possible.

   • Keep small children in a seat with a harness as long as possible.

   • Keep older children in a belt-positioning booster as long as possible.

Newborns usually fit best in an infant-only seat (certified for use up to 20-35 pounds, depending on the model), because the harness can be adjusted snugly. It may be more economical to use a convertible seat from birth, but the slots for the shoulder and crotch straps generally are not as close to the infant's body.

Babies must ride rear facing until they are at least one year old to prevent possible death or lifelong disability by protecting the spine. Babies have heavy heads and weak necks with soft bones and stretchy ligaments. In a frontal collision, which is the type most likely to cause death or severe injury, a forward-facing baby's neck may stretch up to two inches, but the spine can only stretch one-fourth of an inch. At about one year, the bones start to harden, and the baby gradually becomes less vulnerable.

Older babies usually outgrow infant-only seats before they are old enough to face forward at one year. As the baby grows, make sure there is at least one inch of space between the top of her head and the top of the safety seat (the hard plastic, not the puffy fabric). Otherwise, the baby's head may not be fully contained within the seat for best protection in a crash.

When selecting a convertible seat, be sure to check the maximum rear-facing weight, which varies from 20 to 35 pounds. The average baby weighs 20 pounds at nine months and 22 pounds at 12 months. It is wise to choose a convertible seat which allows the baby to face the rear as long as possible.

Convertible seats come with three harness styles: five-point, T-shield, or tray-shield. If a convertible seat is used from birth, it is important to choose one with a simple, five-point harness instead of a harness with an attached shield. The five-point harness can be adjusted to fit almost all sizes and shapes of children up to 40 pounds.

A harness system with a shield is not appropriate for a baby, since the shield lies in front of the face or neck and holds the harness straps away from the baby's body. A 5-point harness has several advantages for  child of any age or size. The straps are placed on the child's shoulders and low on the hips, so that crash forces are absorbed by the strongest parts of the child's body instead of the soft abdomen. If the child is husky, a T-shield may press on chubby thighs, while a tray-shield may squeeze the tummy. In smaller cars, it may be hard to remove the child if the tray-shield cannot be raised  completely.

Safety experts have concerns about safety seats with shields. Tray-shields usually are not covered with energy-absorbing padding to protect the head if it hits the shield. This contact is more likely with a shorter child and a loose harness. In a test series with a 12-month-sized dummy^[1], peak head acceleration was 35% higher for tray-shield restraints than for 5-point harnesses. At least one child (19 lbs.) is known to have received a fatal head injury from contact with a tray shield.

Children from one year to at least 40 pounds

After age one, a child may ride in a forward-facing safety seat; for best protection, however, a small toddler should continue to ride rear facing as long as possible (based on the weight limit shown in the instructions). A few convertible seats are labeled to face forward at 20 to 22 pounds, but the child should not ride facing forward before age one.

When it is time to turn a convertible safety seat to face forward, based on the child's age and size, it is important to re-read the manufacturer's instruction booklet. In general, the safety seat should be adjusted to the upright position, the shoulder straps moved to the top (not center) slots, and the vehicle belt moved to a different part of the safety seat. It is essential that these adjustments be made according to the manufacturer's instructions to prevent possible serious injuries to the child.

Another type of seat for a child who is at least one year old and weighs at least 20-30 pounds, depending on the model, is a forward-facing-only seat with a harness. Most of these seats come with a removable harness and are called combination seats or child seat/boosters. (Some manufacturers call these seats high-backed boosters, which is confusing, because the term “booster” generally is used to describe a seat that lifts the child up to improve the fit of vehicle lap and shoulder belts.) A tall, thin, child may fit in a seat with a harness longer by using a combination seat, which is taller than a convertible seat and may have higher strap slots. For best protection, use the built-in harness until the child outgrows it.

Another important category is that of  safety seats that are built into motor vehicles. Many of them may be used with a harness up to 60 lbs. Built-in seats must meet the same standards as comparable products that are not integrated into the vehicles. Others can be modified for use with the vehicle lap and shoulder belt when the child reaches “booster” age and size.

Children over 40 pounds

If a child is ready to stay properly seated without being held in place by a 5-point harness, a belt-positioning booster seat is the next step.^[2] The best choice is a backless booster or a booster with a removable back that tilts to fit the angle of the vehicle seat. The belt hooks or “arms” on this type of booster keep the lap belt from sliding up on the abdomen.. If the child rides in a vehicle with a low seatback and no head restraint, a backrest is needed to prevent possible whiplash in a rear-end collision. Most boosters are certified for use up 80 pounds; but many children are too tall or too wide in the hips to use a booster after 65-70 pounds. Look for a wide or adjustable base if the child is short and chunky.

If the child has a combination seat (a child seat/booster with a removable harness), the child may use the seat as a booster with the vehicle lap and shoulder belt when he or she outgrows the harness (see instructions for maximum weight). However, many combination seats and some high-back boosters hold the lap belt up too high and/or push the shoulder belt out of the proper position. The shoulder belt should cross the center of the shoulder and lie on the child’s chest.

The belt-positioning strap or clip on the side of a high-back booster should only be used if necessary to prevent the shoulder belt from rubbing against the child’s neck. Caution: do not use the clip if it grips the shoulder belt so it will not retract if there is slack in the belt caused by the child leaning forward. In some cars, the safety  belt can be locked by “switching” the retractor mode at the top of the shoulder section of the belt. This adjustment helps children to sit up straight and prevents the addition of dangerous slack in that portion of the belt when used with a belt-positioning booster.

Most children need to use a belt-positioning booster until they are at least eight years old, depending on the child's height and where the safety belt is attached to the car. The child should continue using a booster until he or she can sit all the way back against the vehicle seat with the knees bending comfortably at the edge of the seat cushion. Otherwise, the child may slouch or slide forward to the edge of the seat, which is very dangerous. The lap belt should touch the hips or tops of the thighs, and the shoulder belt should touch the center of the shoulder and chest. Finally, the child must be able to sit like this for the whole trip. The child must be able to meet all of these criteria before he or she is ready to move out of the booster and start using just a vehicle lap and shoulder belt.^[3]

Children who are under three or four years old or are very active may not stay put if they are not strapped in snugly. Booster seats do not work well for these children because they may lean forward or place the shoulder belt behind the back or under the arm. Special products that provide upper body restraint for children over 40 pounds are available, but they may be difficult to find or to install.

If there are no shoulder belts in the back seat, a booster cannot be used. If the family plans to keep the car for some time, it may be worth the effort and expense to order and install a shoulder belt retrofit kit. These kits may be ordered from vehicle dealers for most cars built between 1972 and 1989.^[4]

Booster seats with a plastic shield in front of the child are not recommended. Shield boosters do not pass current federal standards for children over 40 pounds, and children under 40 pounds should ride in a regular safety seat with a harness.  If the booster has a removable shield, the base of the booster may be used with a lap and shoulder belt. Never use a booster with only a lap belt.

This article was reproduced with permission by: SafetyBeltSafe U.S.A. • P.O. Box 553, Altadena, CA 91003