scope:

This part of ISO 3856 describes a diphenylcarbazide spectrophotometric method for the determination of the "soluble" hexavalent chromium content of the hydrochloric acid extract of the pigment portion of the liquid paint or of the paint in powder form, prepared in accordance with sub-clause 8.2.3 of ISO 6713 or other suitable International Standards. The method is applicable to paints having hexavalent chromium contents in the range a about 0,05 to 5% (m/m). Other methods can be used by agreement between the interested parties, provided that the methods are specific for hexavalent chromium but this spectrophotometric method is the referee method in cases of dispute.