This European Standard defines a method of test for determining the chemical resistance of the surface of the glaze of ceramic tiles at room temperature. The method is applicable to all glazed ceramic tiles except that the pencil test is only applied to glazes from which pencil marks can be removed by means of a dry cloth.
Where the pencil test is not applicable, the glazes can be classified by the change in appearance resulting from chemical action.
The stain test is not applicable to tiles described as part glazed.