ISO 18830:2016 is based on the determination of biological oxygen demand (BOD) and derives from ISO 14851. The testing medium is based on a solid phase and a liquid phase. The solid phase is sandy marine sediment laid in the bottom of a closed flask; the liquid phase is a column of natural or artificial sea water, poured on the sediment. The test material is preferably in the form of a film to be laid down on top of the sediment, at the interface between the solid phase and the liquid phase. This is a simulation of an object that has sunk and finally reached the sea floor.

Measurement of aerobic biodegradation is obtained by measuring the amount of oxygen required to maintain a constant volume of gas in the respirometer flasks, or by measuring the change in volume or pressure (or a combination of the two). The level of biodegradation is determined by comparing the BOD with the theoretical amount and expressed in percentage. The test result is the maximum level of biodegradation determined from the plateau phase of the biodegradation curve.

BPC Blue is a fully automated biodegradability testing system suitable for ISO 18830. Utilising an in-situ carbon dioxide absorption kit, BPC Blue functions as a closed-respirometer for continuous and on-line measurement of oxygen consumption or depletion caused by aerobic respiration of microorganisms. The instrument is suitable for all test protocols which the measurement principle is based on oxygen demand measurement.