Generally, countries that regulate passenger safety have child safety laws that require a child to be restrained appropriately depending on their age and weight. These regulations and standards are often minimums, and with 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. Some countries, such as Australia and the United States, forbid rear-facing child seats in a front seat that has an airbag. A rear-facing infant restraint put in the front seat of a vehicle places an infant's head close to the airbag, which can cause severe head injuries or death if the airbag deploys. Some modern cars include a switch to disable the front passenger airbag for child-supporting seat use.