This European Standard specifies a procedure for determining the degree of aerobic degradation of fully formulated lubricants. The organic material in a fully formulated lubricant is exposed in a synthetic aqueous medium under laboratory conditions to an inoculum from activated sludge. Biodegradation resulting in mineralisation of the organic material can be determined by measuring released CO2 in a total organic carbon (TOC-) analyser. In contrast to existing test methods measuring released CO2 this method uses a precise preparation procedure for non-water soluble organic material. The above mentioned method applies to fully formulated lubricants which a) are water-soluble, non-water soluble or emulsifiable, and b) are not toxic and not inhibitory to the test microorganisms at the test concentration. The presence of inhibitory effects is determined as specified in this European standard. This test method is focused on fresh water as test medium. Tests in sea water are currently not included in this method, but may be introduced later.