BS EN ISO 14851 pdf download

BS EN ISO 14851 pdf download Determination of the ultimate aerobic biodegradability of plastic materials in an aqueous medium — Method by measuring the oxygen demand in a closed respirometer
1 Scope
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, an- other inoculum or a pre-exposed inoculum can be used.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.
ISO 8245:1999, Water quality — Guidelines for the determination of total organic carbon (TOC) and dissolved organic carbon (DOC).
ISO 9408:— 1) , Water quality — Evaluation of ultimate aerobic biodegradability of organic compounds in an aqueous medium by determination of oxygen demand in a closed respirometer.