A giant foam building block for children includes an inner core, an outer layer and a barrier skin. The inner core is made of foam or expanded polystyrene having a lower density than the outer layer. The inner core is softer than the outer layer, but both have a hardness less than 20 Shore A. A resin is sprayed onto the inside surface of a mold before the inner core is placed in the mold and the outer layer is molded around the inner core. The outer layer is molded such that an integral skin forms on the inner surface of the mold. The resin attaches to the integral skin and together forms a barrier skin that becomes the outer surface of the block. The block has no covering over the barrier skin. Children are not exposed to the TDI-based foam core which is sealed off by the outer layer.