This International Standard specifies a method, by measuring the oxygen demand in a closed respirometer, for the determination of the degree of aerobic biodegradability of plastic materials, including those containing formulation additives. The test material is exposed in an aqueous medium under laboratory conditions to an inoculum from
activated sludge, compost or soil. If an unadapted activated sludge is used as the inoculum, the test simulates the biodegradation processes which occur in a natural aqueous environment; if a mixed or pre-exposed inoculum is used, the method can be used to
investigate the potential biodegradability of a test material.
The conditions used in this International Standard do not necessarily correspond to the optimum conditions allowing
maximum biodegradation to occur, but the standard is designed to determine the potential biodegradability of plastic materials or give an indication of their biodegradability in natural environments.
The method enables the assessment of the biodegradability to be improved by calculating a carbon balance (optional, see annex E).
The method applies to the following materials: Natural and/or synthetic polymers, copolymers or mixtures thereof. Plastic materials which contain additives such as plasticizers, colorants or other compounds. Water-soluble polymers. Materials which, under the test conditions, do not inhibit the microorganisms present in the inoculum. Inhibitory effects can be determined using an inhibition control or by another appropriate method (see e.g. ISO 8192[3]). If
the test material is inhibitory to the inoculum, a lower test concentration, another inoculum or a pre-exposed inoculum can be used.
Diese Internationale Norm legt ein Verfahren fest, mit dem durch Messung des Sauerstoffbedarfs in einem geschlossenen Respirometer der Grad der aeroben Bioabbaubarkeit von Kunststoffen, einschließlich solcher Kunststoffe, die Formulierungs-Additive enthalten, bestimmt werden kann. Die Prüfsubstanz wird in einem wässrigen Medium unter Laborbedingungen einem Inokulum aus Belebtschlamm, Kompost oder Boden ausgesetzt. Wird ein nicht adaptierter Belebtschlamm als Inokulum verwendet, werden durch die Prüfung die Bioabbauprozesse simuliert, die in einer natürlichen wässrigen Umgebung auftreten; wird ein gemischtes oder voradaptiertes Inokulum verwendet, kann das Verfahren dazu dienen, die potentielle Bioabbaubarkeit einer Prüfsubstanz zu untersuchen.