This European Standard gives guidance for the determination of organic carbon indrinking water, ground water, surface water, sea water and waste water. It dealswith definitions, interferences, reagents, and the sample pretreatment of water samples with a content of organic carbon ranging from 0,3 mg/ l to 1000 mg/ l while the lower value is only applicable in special cases, for example drinking water, measured with instruments capable of measuring these low levels.