A rear-facing car seat should never be installed with an active airbag in the front seat. Today, most car manufacturers offer some form of safe disconnection of the airbag and if it has been actioned, the passenger front seat works fine for the rear-facing car seat. Regarding a forward-facing car seat in the passenger front seat, the basic rule is that the airbag must be deactivated if the child is under 140cm. However, today there are newer cars that have airbags where everyone who is travelling forward-facing, regardless of height, can sit even though the airbag is active. It is therefore important to read the car’s instruction manual or check with your car manufacturer as to what applies to your car.
Please note, side airbags do not pose a danger to children whether they are riding in a rear-facing or forward-facing car seat.