This International Standard specifies a method, by determination of carbon dioxide (C_O2), for the evaluation in anaqueous medium of the ultimate biodegradability of organic compounds at a given concentration by aerobic microorganisms.

The method applies to organic compounds which are:

• water-soluble under the conditions of the test, in which case removal of DOC may be determined as additional information (see annex D);
• poorly water-soluble under the conditions of the test, in which case special measures may be necessary to achieve good dispersion of the compound (see, for example, ISO 10634);
• non-volatile or which have a negligible vapour pressure under the conditions of the test;
• not inhibitory to the test microorganisms at the concentration chosen for the test.