Characterization, classification and stabilization of industrial wastes for hazard property HP3: Flammable self-heating; assessment and evaluation of 50 industrial wastes

Highlights: • Evaluation of self-heating in 50 industrial wastes. • Reevaluation of entry types in List of Waste; two absolute-non-hazard wastes exhibit self-heating. • Limestone soil works as stabilizer agent in inorganic self-heating wastes. A pilot assessment procedure is introduced and used for the self-heating behavior of 50 industrial wastes based on UN N. 4 test and their subsequent classification as hazardous or non-hazardous, according to the Waste Framework Directive (WFD). When a waste contains self-heating substances it is classified as 'Hazardous Waste' by hazard property HP3: Flammable according to Regulation (EU) No 1357/2014. Self-heating is considered as a precursor stage to spontaneous ignition and fire under certain circumstances, with environmental effects and both human and property losses. The influence of the following parameters on the self-heating nature of the industrials wastes was assessed: temperature, granulometry and moisture. It was demonstrated that although some wastes are classified as absolute non-hazardous (ANH), they may still exhibit self-heating and thus must be classified as hazardous by HP3. It seems that there is a gap between the definition of hazardous waste according to WFD and the entry type of List of Wastes (LoW), regarding the ANH entries. This was found to be the case with two of the wastes examined. Finally, for a waste exhibiting self-heating, experiments were performed with addition of inert material, in order to secure safe management of the waste.