This control is intended essentially for the detection of alcoholic impurities in aceton. The principle consists in treatment of a test portion with Agulhon's reagent (potassium dichromate solution added to nitric acid solution) under specified conditions. The presence of certain impurities, in particular alcoholic ones, is indicated by a blue or violett coloration. International Standards ISO 757/1 to ISO 757/5 cancel and replace ISO Recommendation R 757-1968, of which they constitute a technical revision. This document has also been approved by the International Union of Pure and Applied Chemistry (IUPAC).