This International Standard specifies the requirements and corresponding test methods for manufactured and natural micaceous iron oxide (MIO) pigments, in dry form, used primarily in protective coatings for steelwork. In accordance with current practice, the general requirements for micaceous iron oxide pigments have been sub-divided to give a) those requirements that are essential (see Table 2) and b) those requirements that are conditional upon prior agreement between the interested parties (see Table 3). In certain instances, reference may be made to an agreed reference pigment.