Generally, countries with passenger safety rules includes laws regarding child safety in a manner that the child must be restrained depending on their age and weight.
These regulations and standards are often minimums and that for each graduation to the next kind of safety seat, there is a step down in the amount of protection a child has in a collision. Car seats have been found to cause severe and fatal injuries to the child when fitted in a the front seat with airbags.
In 2003, the American Academy of Pediatrics suggested that infants “should spend minimal time in car seats (when not a passenger in a vehicle) or other seating that maintains supine positioning” to avoid developing positional plagiocephaly ("flat head syndrome") .________
In 1990, the ISO standard ISOFix was launched in an attempt to provide a standard for fixing car seats into different makes of car, that now includes the top tether.
The U.S. version of this system is called LATCH. Generally, ISOFIX system can be used with Groups 0, 0+ and 1.
There are several types of car seat depending on the position of the child and size of the seat.
The United Nations standard ECE R44/04 categorises these into 4 groups: 0-3.