Increasing occurrences of waste fires that are caused by improperly discarded lithium-based portable batteries threaten the whole waste management sector in numerous countries. Studies showed that high quantities of these batteries have been found in several municipal solid waste streams in recent years in Austria. This article reveals the main influence factors on the risk of lithium-based batteries in their end-of-life and it focuses on the quantification of damages to portable batteries during waste treatment processes. Hazards are identified and analysed and potential risks in waste management systems are comprehensively assessed. In two scenarios, the results showed that the potential risks are too high to maintain a sustainable form of waste management. According to the assessment, a small fire in a collection vehicle is located in the risk graph’s yellow region (as low as reasonably practicable, ALARP), while a fully developed fire in a treatment plant has to be classified as an unacceptable risk (red region of risk graph). Finally, basic recommendations for action were made.