Child Seat Safety Related Issues

Angle of recline for a rear facing seat, the seat should be reclined so that the angle of the back surface is not more than 45 degrees from vertical. As the baby grows, the angle should be decreased. For a forward facing seat, the most upright position is the safest in terms of load distribution. Newer model child seats have a level, which advises users the correct angle of recline. Some manufacturers mislabeled their instructions which allowed for excessive reclination.

Chest clip holds the shoulder straps together. If not spring loaded, the clip could slide down allowing the child's shoulders to slip out which could lead to complete or partial ejection. The clips that are not spring loaded also have a tendency to be flimsy and one of the teeth can shear rendering the shoulder straps ineffective.

Shoulder harness slots - two common problems. Mislabeling which slot to put the shoulder belt through is most common. For rear facing child seats, the shoulder straps should be at or just below the child's shoulders. For forward facing child seats, put the shoulder strap in the slot at or above the child's shoulders. The slots also have a tendency to be weak and un-reinforced such that the slots tear out under load ejecting the child.

Harness strap tightness - this is a major problem because users will wrap the child in bulky clothing or a blanket then the harness is not tight enough. However, nothing advises parents about swaddling a child in a blanket. Also some manuals differ in how they define tightness. Some say one finger between the straps. Some say two, others say three fingers.

3-point harness - this harness configuration has two straps over the shoulders and a single crotch strap. A child is susceptible to ejection or submarining with this design because there is no pelvic support.

Tray shield - located on a convertible child seat. The tray breaks off and impacts the child or the child impacts the tray and suffers injury because the tray was not adequately padded. Testing has shown that tray shields result in 35% higher head peak acceleration forces than 5-point harnesses.

T-shields - shoulder straps are attached to a flat, plastic fairly rigid stalk that buckles into the child seat shell between child's legs. Testing has revealed that a child's throat the top of the T-shield. Also, neck forces are 40% higher shields compared to 5-point harnesses.

Plastic shell fracturing - over the years, shell deformation has resulted in unnecessary child injury.

Head excursion - before September 1999, the forward head excursion was 32 inches forward of a point located five inches rearward of the seat bight. After September 1999, the head excursion has been reduced to 28 inches from that point but with a tether device. There is still no lateral head excursion requirement.

Lateral child seat excursion - Vehicle safety belts are not properly designed to laterally restrain a child seat. Lateral movement places the child in harm's way from intruding components. The top tether and LATCH system have minimized this problem.

Lateral head excursion - focuses on the failure to use a winged seat design to help minimize head excursion in side impacts.

Twisted harness belt - the load carrying capacity of the straps is decreased to the point the harness can separate under otherwise survivable accidents.

Low shield booster seats - these were first introduced in the US in 1979 and problems quickly followed because there is no harness restraint to retain the upper torso. As a result, children in shield boosters can be ejected or injured due to head contact or abdominal loading. One company recommended to its US customers that it was safe to use a shield booster seat for children under 40 lbs. This was contrary to the message it gave its Canadian customers. In 1991, the NHTSA wrote that "shield boosters may not provide adequate protection because they don't offer adequate upper body restraint and children can be ejected from them."

Unstable base - a narrow or unstable base that allows the child seat to move excessively sideways due to the vehicle belt placement can allow a child to impact the striking object or vehicle interior.

No positive belt capture feature - this has been seen primarily on no-back booster seats. The vehicle's belt routed around the booster but was not captured or locked in place. As such, the booster seat could slip out from under the vehicle's belt allowing the child to be ejected. On more conventional child seats the vehicle’s belt is routinely not capable of being locked to the child seat. This lack of retention can allow excessive lateral movement.

Vehicle seat incompatibility - due to the angle of the seat rake and seat bight location, the child seat cannot be placed securely to the vehicle.