scope:

This Standard specifies a method, by determination of the oxygen demand in a closed respirometer for the evaluation in an aqueous medium of the ultimate biodegradability of organic compounds at a given concentration by aerobic micro-organisms. The conditions described in this Standard do not always correspond to the optimal conditions for allowing the maximum degree of biodegradation to occur. The method applies to organic compounds which a) are soluble in the test conditions; b) are insoluble in the test conditions, in which case special measures may be necessary to achieve good dispersion of the compound; c) do not reach and react with the CO₂ absorbant; d) are volatile, provided that a suitable respirometer is used; e) are not inhibitory to the test micro-organisms at the concentration chosen for the test. The presence of inhibitory effects can be determined as specified in 8.3, or by using any other method for determining the inhibitory effect of a compound on bacteria (see, for example, ISO 8192).