ISO 6794:1981

A test portion is treated with a solution of bromine in absolute methanol saturated with sodium bromide (Kaufman solution). After addition of potassium iodide solution the liberated iodine is titrated with standard volumetric sodium thiosulfate solution. The degree of unsaturation is expressed as iodine value, the number of grams of iodine absorbed by 100 g of a substance under specified conditions of test.