Aiming to reach circularity and resource efficiency, the metal industry pushes towards recycling secondary products instead of producing from primary material. This increases the use of scrap, which can bring about several benefits but could also come at the expense of the materials' quality and the potential loss of valuable resources. The above is mainly a result of the likely accumulation of unwanted elements throughout the recycling process, which may dissolve and become difficult to extract from the metal's melt, turning into what is known as tramp elements. This study focuses on the opportunity to limit the accumulation of unwanted elements before they end up in the molten solution. Taking an exploratory approach with the use of observation and expert interviews, this study examined where and how unwanted elements enter the recycling system. Eight element types were identified and categorised after the intentionality of their addition and their desirability in the end product. Thereafter, this article proposes a taxonomy based on the way in which these are present inside the furnace before melting, suggesting that the manner elucidates the entry points where impurities are introduced in the recycling stream. By introducing a taxonomy, this study aims to pave the way for developing strategies and research on how to minimise or prevent the presence of these elements in recycled metals, thereby increasing the quality of the recycling process.