This book on the conversion of wastes (polystyrene waste, sawdust and rice husk) to usefulness is a breakthrough. These wastes had been a menace on the environment due to numerous challenges of post-usage. The wastes were processed and characterized via Fourier Transform Infrared and followed by the formulation of adhesive from polystyrene waste with admixture using Design Expert Software Version 6.0.8. The results of the formulated adhesives based on the experimental design was characterized and optimized for the best fit. The best formulation which is resin seven adhesive two coded (Ri7Adh2) was subjected to further characterizations for Microstructural and Physicochemical properties. The produced adhesive was then applied in production of particleboards from sawdust and rice husk wastes, and optimized. The optimized and best were reproduced and further characterized for Microstructural analysis, Safety, Thermal comfort, Electrical insulation properties using ANSI, ASTM, BS, JIS standards. The results revealed that, waste polystyrene has been degraded and transformed into new product. The produced particleboards showed high quality and safe for indoor usage.