A comprehensive methodology for assessing the hazardousness of waste categorized in the european union legislation as “mirror entries”—case studies

In the European Union List of Wastes, the category of “mirror entry” waste refers to either hazardous or non-hazardous waste, depending on their composition and specificity. Classifying waste as hazardous or non-hazardous is essential because it influences the feasibility and economic viability of subsequent management methods. Thus, waste classification represents a challenge both for the scientific community and for the producers/holders of waste. The methodology presented in this paper describes the stages that are the basis for evaluating the dangerousness of “mirror entry” waste and the potential factors that influence the evaluation process. Three case studies that represented three types of industrial waste were selected: waste from the non-metallic minerals industry (W1), waste from glass manufacturing (W2), and waste from the iron and steel industry (W3). The case studies were characterized and evaluated according to hazardous properties and the assignment of a waste code. The W1 and W2 waste samples did not present the hazardous properties HP1–HP15 and were included in the non-hazardous waste list. The W3 waste sample exhibited five dangerous properties and was classified as hazardous waste. The assessed wastes maintain the classifications as long as there are no changes in the technological process generation and in their composition.