“…Table 1 shows the possibilities of recycling waste in polyurethanes. [58][59][60][61] rigid polyurethane foams 15 -with the increase in the concentration of wood flour, there is a decrease in compression properties and a slight increase in thermal conductivity improves thermal stability buffing dust [62] rigid polyurethane foams 5 -improve the mechanical properties reduce the transition glass temperature thermoplastic elastomers and thermoplastic polyurethane [63] rigid polyurethane foams 2.5 -increase the compression modulus, tear resistance, and Young's Modulus ground corncake [64] flexible polyurethane foams 10 -improve the mechanical strength of the foams, resulting in better tensile strength and elongation at break values enhance the thermal behavior of the foams, such as thermal conductivity and temperature response improve the morphology and cell shape of the material Tetra Pak ® [65] polyurethane foams 20 -led to improved thermal stability, especially during the first degradation stages a significant increase in compressive stress, with values at 10% deformation four times higher than that of pristine foam coffee grounds [66] rigid polyurethane foams 20 After conducting the classification based on the utilized waste and the obtained polyurethane materials (PUR), it becomes apparent that there is significant potential to utilize waste in the production of various polyurethane products. In order to classify the waste in accordance with the Commission's guidelines on the technical classification of waste and Commission Decision of 18 December 2014 amending Decision 2000/532/EC on the List of Waste pursuant to Directive 2008/98/EC of the European Parliament and of the Council (2014/955/EU), it can be divided into several main categories: wastes resulting from exploration, mining, quarrying, the physical and chemical treatment of minerals (basalt waste); waste from agriculture, horticulture, aquaculture, forestry, hunting and fishing, food preparation and processing (bagasse, biochar, sawdust, coffee grounds, residual pineapple cellulose, chicken feathers, egg shells, turkey feather fiber, cuttlebone, ground corncake, sunflower husks, rice husks, and buckwheat hulls, pine seed shells, yerba mate, walnut shells, silanized walnut shells, mussel shell); waste from wood processing and the production of panels and furniture, pulp, paper and cardboard (wood flour, buffing dust); waste from organic chemical processes (waste lignin); waste not otherwise specified in the list (thermoplastic elastomers and thermoplastic polyurethane, Tetra Pak ® , glass fibers, ground rubber powder, tire rubber, glass fibers) [83].…”