Specifies the determination of total reducing matter and of reducing compounds other than formic acid. The principle consists in oxidation of formic acid and other reducing compounds in a test portion with an excess of sodium hypobromit solution. Determination of the excess sodium hypobromite by iodometry. Oxidation of reducing compounds other than formic acid with an excess of potassium bromide-bromate solution in an acid media. Determination of the excess potassium bromide-bromate by iodometry. Determination of the formic acid content from the difference between the two determinations. Is applicable to products having formic acid contents, between 0,02 % (m/m) and 0,35 % (m/m).