**Abstract**

Global denim jeans market size is over 70 billion dollars today, and it continues to grow with a compound annual growth rate (CAGR) of 2%. As a reflection of this annual growth, systems' waste generation also increases. Textile waste including denim accounts for nearly 5% of all landfill space, according to the Environmental Protection Agency (EPA). Today, efficient recycling technologies are essential to revive the waste generated. Recycling technologies potentially represent a new way to engineer products. This book chapter analyzes these different recycling technologies and their advantages and challenges and concentrates on denim fabrics produced with recycled content. Life cycle assessment (LCA) methodology is adopted to quantify and compare the environmental impact of recycled denim fabrics. The chapter concludes the challenges and the future of recycling, creating systems, and engineering of waste. The view of seeing waste as a raw material potentially represents a new opportunity to design circular systems.

**Keywords:** denim recycling, textile waste, life cycle assessment, design for sustainability, circularity
