This International Standard specifies requirements for flexible load-bearing polyurethane foam of the polyether type. It is applicable to flexible polyurethane cellular materials manufactured in block, sheet and strip form, in moulded and fabricated shapes, and as reconstituted material, used for load-bearing applications in general, but excluding carpet backing and underlay. It thus primarily relates to the quality of polyurethane foam used for comfort cushioning purposes. The foam is classified according to performance during a fatigue test, indentation hardness index being used as a secondary means of grading the material. This International Standard is not applicable to polyurethane foams foamed in place or to foams for use in heat-welded systems unless for load-bearing purposes. Recommended applications for the range of flexible polyurethane foams covered by this International Standard are listed in Annex A.