As bio-derived plastics in agriculture (agricultural films to mulch sheets, and planters) are gaining widespread use, the issue has to be faced whether these are completely biodegradable in natural environments. ISO 17556 is a standard test method to define the aerobic biodegradability of plastic materials in soil. ISO 17556 is to provide a degradability in soil solution for plastics materials under aerobic (oxygen-augmented) field conditions, and assess how microbes use the plastic. It is usually the oxygen demand in a closed respirometer or the carbon dioxide evolved obtained from measurements of this.
ISO 17556 Test Method
| Test procedure | The purpose of this test is to obtain the optimum rate of biodegradation of a plastic material in a test soil through the control of soil humidity, and to measure the ultimate biodegradability of the material. The plastic, which is the only source of carbon, is added to the soil. This is then allowed to stay in a flask for a certain amount of time. This is done until biodegradation has plateaued at a constant rate, or for a total of six months. |
