Plastic waste is a major and persistent source of pollution, with significant impacts on ecosystems, human health and climate. This section highlights globally aligned knowledge products to support a full life-cycle approach, reducing unnecessary plastics, promoting reuse, and improving collection and recycling systems. For Istanbul and Türkiye, growing consumption and urban waste streams make plastics a critical entry point to advance circular economy practices, reduce leakage into land and marine environments, and support more sustainable material use.