Standard Specification for Yellow Iron Oxide Hydrated

This specification covers the pigment commercially known as yellow iron oxide, hydrated. The pigment shall be a manufactured yellow iron oxide obtained by chemical reaction and shall be soft, finely powdered, and free of admixtures of other substances. The pigment shall conform to the composition requirements prescribed for: hydrated oxide of iron, total oxide of iron, loss on ignition, moisture and other volatile matter, water soluble matter, and coarse particles (total residues retained), and to the specified hydrogen ion concentration (pH value). The paste in oil shall be made by thoroughly grinding the specified pigment with linseed oil and the paste shall conform to the requirements prescribed for the following: pigment, nonvolatile vehicle, moisture by distillation, coarse particles and skins, and consistency by Stormer viscometer. The mass color character of the tint and the tinting strength formed by a mixture with a white pigment shall be within the specified limits. The methods for sampling, chemical analysis, and tests to determine conformance to the specified properties are given.