http://www.mto.gov.on.ca/english/safety/carseat/choose.shtml
Pre-school to 8 years old
The law requires booster seats for children who have outgrown a child car seat but are too small for a regular seat belt.
Booster seats are required for children under the age of eight, weighing 18 kg or more but less than 36 kg (40-80 lb.) and who stand less than 145 cm (4 feet-9 inches) tall.
A child can start using a seatbelt alone once any one of the following criteria is met:
child turns eight years old
child weighs 36 kg (80 lb.)
child is 145 cm (4 feet-9 inches) tall.
Seatbelts are designed to protect adults. Booster seats raise the child up so that the adult seatbelt works more effectively. Booster seats protect against serious injury 3 ½ times better than seatbelts alone.
A lap and shoulder combination belt must be used with all booster seats. Your child's head must be supported by the top of the booster, vehicle seat or headrest. The shoulder strap must lie across the child's shoulder (not the neck or face) and middle of the chest, and the lap belt must cross low over the hips (not the stomach/abdomen). Never use seatbelt adjusters.
Between 18 and 36 kg (40—80 lb.)
Booster seat
Use with lap and shoulder belt
