This document specifies a method for the determination of the loss on ignition (LOI) of dry matter at 550 °C. The dry matter is determined according to EN 15934. This method applies to the determination of loss on ignition of sediment, sludge, treated biowaste, soil and waste. NOTE The loss on ignition is often used as an estimate for the content of organic matter in the sample. Inorganic substances or decomposition products (e.g. H2O, CO2, SO2, O2) are released or absorbed and some inorganic substances are volatile under the reaction conditions.