Nanotechnology is one of the most significant scientific and industrial breakthroughs of the twenty-first century. With applications that cross scientific boundaries from electronics to medicine, to advanced manufacturing, to cosmetics nanotechnology has the potential to dramatically change lifestyles, jobs, and whole economies [1]. However, many of the materials and processes currently used not only are dependent on nonrenewable resources but also create hazardous wastes. The combination of green chemistry techniques with nanotechnology applications has thus become a key component of the nanotechnology future. The use of natural ingredients to synthesize nanomaterials and design environmentally benign synthetic processes has been extensively explored. While many of these so-called "green nanotechnologies" are now finding their way from the laboratory to commercial application, green nanotechnology still faces significant challenges. This article presents the recent advances and challenges in green nanotechnology, and suggests ways to improve the commercial readiness of these technologies. (C) 2015 Elsevier Ltd. All rights reserved.