note | 10.06.2024

Ash treatment according to ITAD guidelines

Waste legislation classification of ash from household waste incineration

Approx. 6 million tonnes of bottom ash (IBA) per year are produced in the thermal treatment of municipal solid waste and commercial waste in Germany. 

The incinerator operator must arrange for testing to determine whether a specific IBA meets the conditions of the legal presumption as nonhazardous waste. In the worst case, the heavy metal levels lead to classification as environmentally hazardous waste in accordance with the German Waste List Ordinance (Abfallverzeichnisverordnung).

Working on behalf of the IGAM and ITAD associations, bifa developed guidelines on the classification of bottom ash from the thermal treatment and energy recovery of household waste and household-type waste. In these guidelines, the single substances and substance groups in the bottom ash are subjected to differentiated consideration. 

Classification by a three-stage procedure 
This three-stage process provides for general screening of the hazard-relevant properties, a worst-case analysis assuming that all elements are present in the most hazardous expected compound and an evaluation of the realistic composition based on scientific expertise. The practical guidelines are recommended by the Bavarian State Ministry of the Environment and Consumer Protection (Bayerischen Staatsministerium für Umwelt und Verbraucherschutz) as a suitable basis for the classification of IBA according to the Waste List Ordinance.

It differentiates between the basic test, which provides a basis for the assessment of all hazard classes and the periodic test in which only the hazard-relevant property HP 14 (environmentally hazardous) is explicitly tested. The practical guidelines provide for additional interim tests with significantly reduced test scope for ongoing monitoring of the ash quality.

bifa carries out these classification and follow-up control tests according to the practical guidelines. This includes proper sampling in accordance with the sampling regulations LAGA PN 98, high-quality sample preparation by crushing, grinding and screening, and analytical characterisation in the laboratory, as well as detailed assessment of the results with suggestions for classification of the respective ash sample.

The legal basis of the waste classification is not static. This mainly concerns the harmonised classification of single substances, as well as the definition of hazard-relevant properties and the rules on the basis of which the substances are classified. bifa therefore updates the guidelines regularly.