This European Standard specifies quantitative methods for determining the TON and TFN of waters and also a qualitative method for determining any abnormal odour and/or flavour. It is essential that the safety remarks in Clause 5 are taken into account.
Two quantitative methods are described:
a short method applicable when either a sample has no odour and flavour or when the odour and flavour are to be compared with a specified threshold number;
a full method applicable when the threshold number for the sample is to be determined.
For both quantitative methods, two different methodologies are described:
unforced choice in the standard;
forced choice in Annex B.
Both methods are applicable for quantifying the odour and flavour of drinking water and/or migration waters from materials in contact with waters.
NOTE – The choice of the quantitative or qualitative method is depending on the national regulations, and on the type of water to be assessed (raw water, distribution water, migration water...)