New California Law Mandates Booster Seats for Tots

January 11, 2002
News Office: Maureen McInaney (415) 502-6397

Children improperly restrained in toddler and infant car seats are at risk to be injured, according to a recent study by investigators at the San Francisco Injury Center (SFIC). The researchers note that it is likely that similar installation errors will occur with booster seats.

New regulations mandate booster seats for children up to age six or weighing up to 60 pounds.

"The new state booster seat law which took effect January 1, 2002 can save lives by requiring a greater proportion of our youthful population be placed in a protective seat. Yet, it does not address preventable injuries related to improper car seat installation," said Dr. Margaret Knudson, UCSF professor of surgery at San Francisco General Hospital Medical Center (SFGHMC) and director of the SFIC.

Investigators from the SFIC, in partnership with the San Francisco SAFEKIDS coalition, recently completed a series of car seat safety checks (which included primarily toddler and infant seats) throughout San Francisco.

Of the 396 seats checked by certified examiners, 93 percent were either misused or incorrectly installed. With infant and toddler seats, examiners found that a majority of the errors occurred with the car seat harness or seat belts or with the harness clips. The two most common problems encountered were that the vehicle safety belt did not hold the car seat tightly in the vehicle and that the harness straps were not snug against the child. These findings are similar to those from other car seat safety checks conducted across the country, explained Knudson.

"In a car crash, installation errors involving any of these car seats could result in the child or seat acting as projectiles. This can result in serious head or neck injuries," said Knudson. "Additionally, improperly used restraint devices can be associated with injures to the intestines and major blood vessels."

The new California law, authored by State Senator Jackie Speier, extends the use of car seats to children up to age 6 or weighing up to 60 pounds. Prior regulations stopped at age 4 or 40 pounds, leaving a gap between young children and heavier, taller children who can use standard lap and shoulder belts, explained Knudson. Booster seats provide protection by lifting the child up so that the safety belt fits correctly and prevents the child or seat from being propelled during a car crash. Violation of the new law will result in a $270 fine.

Motor vehicle crashes remain the leading cause of death for children 1-14 years of age. Riding unrestrained is the single greatest risk factor for death and injury among child motor vehicle occupants. Unrestrained children in vehicles are twice as likely to die or be injured as those who are restrained. Despite the proven effectiveness of car seats and booster seats, however, their use is far from universal, particularly as children grow older.

Additionally, even when car seats and booster seats are used, errors in installation and positioning can cause them to be ineffective in preventing injuries or death, explained Knudson.

In addition to their work with car seats, researchers at the San Francisco Injury Center at the University of California San Francisco, are actively involved in surveillance work on pedestrian crashes in the city, and on injuries resulting from violence. The Center, which has recently been refunded for five years by the Center for Disease Control and Prevention (CDC) in Atlanta, has been recognized as a center of excellence in both clinical and laboratory investigations in the field of injury control. Investigations stem from basic work in the area of traumatic brain injury to defining the biomechanics of fractures of the spine.

Other investigations focus on the diagnosis and treatment of various types of injuries resulting from car crashes, falls and other traumatic mechanisms. The psychological stress suffered by children who are injured is also an area of interest for Center researchers. Finally, SFIC personnel are involved in educating medical professionals as well as the public in the area of injury prevention and control.

Parents and caregivers can avoid the tragedy of car seat related injuries by having their car seats checked to ensure proper installation. For a list of common installation errors or to locate convenient car seat examination sites, parents and caregivers can call 800-441- 1888 or visit or the California Vehicle Occupant Safety Program at For more information about the San Francisco Injury Center, visit: