AS 4351.6-1996

Provides guidance for the determination of the 'ready' biodegradability of poorly soluble organic compounds. Four techniques are provided for dispersing organic compounds which are not soluble enough to be analysed using the relevant test method in the normal manner. The techniques are applicable to the methods provided by AS 4351.3 and AS 4351.4. Identical with and reproduced from ISO 10634:1995.

This International Standard describes four techniques for preparing poorly water-soluble organic compounds and introducing them into test vessels for a subsequent test on biodegradability in an aqueous medium using standard methods. The test compounds concerned are not sufficiently soluble in water to perform the biodegradability tests in the normal manner, as described in the respective test methods indicated in clause 2.The preparation techniques are as follows:- direct addition (clause 3): this technique is restricted to non-volatile test compounds if inert supports or solvents are used;- ultrasonic dispersion (clause 4): this technique may be applied to non-volatile liquid and solid compounds;- adsorption on an inert support (clause 5);- dispersions or emulsions with an emulsifying agent (clause 6).The subsequent tests on biodegradability are primarily methods using the analysis of the released carbon dioxide (see ISO 9439) and the determination of the oxygen consumption (see ISO 9408). This International Standard does not describe the test methods; it is restricted to describing the techniques for introducing the test substances into the test medium and to keep them in a dispersed state. These techniques are implemented while observing the experimental conditions described in the standardized methods for evaluating biodegradability. It should be noted that volatile chemicals may not be tested by the carbon dioxide method specified in ISO 9439.

First published as AS 4351.6-1996.