LATCH stands for “Lower Anchors and Tethers for Children”. They became mandatory in vehicles in 2002 to help parents better secure the baby seat in the car and eliminate seat belt incompatibility. Pursuant to the actual law the lower anchors are designed to support a maximum weight of 65 lbs. Most parents are not aware that this weight includes the child and the child seat. When the total weight exceeds 65 lbs the child seat must be secured with the car seatbelt.
In order to make this information clear to parents the new LATCH law effective in February 2014, will require child seat manufacturers to modify their label to make sure parents understand that their child weight determines how long they can use the lower anchors.
This legislation was heavily pushed by automakers in order to protect themselves from product liability lawsuits as baby seats these days are heavier than those manufactured in 2002 and are putting increased strain on the lower anchors.
The heaviest seat presently weighs around 33 lbs therefore LATCH can only be used until the child is 32 lbs which can be as young as two years old. Seat belt incompatibility may also cause parents to prematurely use an easier to install booster seat, a product which is not as reliable as a harnessed seat in case of an accident.
Previous crash tests have proven that LATCH installation is the safest design for child seats.
A law that would really improve child seat safety would be to require automakers to design the lower anchor to a higher strength so LATCH could be used longer.
For more info check Consumer Reports.