In the context of the steel industry, residuals refer to the low level elements that may exist naturally, byproducts of steelmaking or scrap materials, or impurities that remain after the primary production of steel. These usually refer to trace amounts of elements that are not fully removed during the steelmaking process. Residuals might also include the small amounts of alloying elements (such as carbon, manganese, or silicon) that are still present in the final steel product, despite efforts to refine the material. These residual elements can impact the steel's final properties and quality so are carefully controlled.