ODOR AND FLAVOR IN WATERS - QUANTITATIVE METHOD FOR A NEW EUROPEAN STANDARD

In the majority of the European Community, the assessment of odours an d flavours in water supplies are carried out only by sensory analysis. Consequently it is essential for institutes and water companies to us e the most accurate method in evaluating odour and flavour in drinking water. Until recently, most of the European countries had their own m ethod or national Standard. Due to the requirements for odour and flav our in EC Directive 80/778 on drinking water quality, applicable throu ghout Europe, there was a need to standardise their method of evaluati on. At the time, no ISO Standard for flavour and odour existed. Moreov er, since the materials intended for contact with drinking water must not induce organoleptic problems, manufacturers of pipes, fittings and coatings are also concerned in a standardization. This paper presents the state of the art for flavour and odour evaluation in European cou ntries and the next European Standard for these parameters. The Standa rd will be based on the dilution method to obtain a threshold flavour number (TFN) and a threshold odour number (TOM) of a water. The princi ple is to compare the successive dilutions of water samples with a ref erence water. Several methods can be used, for example paired and tria ngle test, forced and unforced choice. The Standard also includes the selection, training and calibration of panellists. This Standard was e laborated within the scope of CEN/TC 230 ''Water Analysis'', and was a chieved through the active participation of experts from water institu tes, water companies and manufacturers of materials.