ISO 7827:2010 specifies a method for the evaluation of the “ready” and “ultimate” biodegradability of organic compounds at a given range of concentrations by aerobic microorganisms. In this context, ISO 7827:2010 also gives specific definitions for the terms “ready” and “ultimate”.

The method applies to organic compounds which are: a) soluble at the concentration used under the conditions of the test [dissolved organic carbon (DOC) concentrations of 10 mg/l to 40 mg/l]; b) non-volatile or having a negligible vapour pressure under the conditions of the test; c) not significantly adsorbable on glass and activated sludge; d) not inhibitory to the test microorganisms at the concentration chosen for the test.

The method is not suitable for waste waters, as they usually contain significant amounts of water-insoluble organic carbon, which is not included in DOC measurements.