Washington state law requires that children less than eight years old be restrained in appropriate child restraint systems (car seats or booster seats) unless the child is 4'9" tall. Children who are 8 or older, or who are 4'9" or taller, must be restrained with a vehicle seatbelt or appropriate child safety restraint. Children under 13 years of age must be transported in rear seats where it is practical to do so.
Washington state has created one of the strongest car seat safety laws in the United States. The new law, which went into effect June 1, 2007, also requires infants who are under one year of age AND under 20 pounds to ride in a rear-facing car seat. This law is also known as the Anton Skeen Law, named for a child who died in a rollover crash because, although he was properly restrained by state law at the time, the vehicle seatbelt could not protect him during the crash.
More State Car Seat Laws and Car Seat Safety Resources