For about 20 years rearward facing child seats have been used in Sweden for children up to the age of 3 years. These seats are usually mounted in the front seat passenger position leaning against the dashboard. The protection performance has been shown to be excellent (90-95% injury reduction) and this concept is now being adopted in other countries. A passenger air bag can obviously be dangerous in combination with this type of child seats and some dynamic tests have been done with different combinations. These tests show that the dummy accelerations will reach very high levels and that some child seats will disintegrate. This paper will present these results and discuss possible countermeasures. The new requirements for roadside safety features that are now being developed in Europe and the USA are based on the assumption that passengers are not using seatbelts. These requirements will encourage the development of systems with a low g-level at the beginning of the collision in order to let the unbelted occupants hit the dashboard with a low impact speed. During this phase the air bag will probably not deploy. When the passenger is in contact with the instrument panel the g-levels will be allowed to increase and the air bag will deploy. This is obviously a dangerous situation. This paper will discuss the present state of these requirements and the problems with air bag use in these situations.