Nanofillers are an important component of nanocomposites forming the filler phase mixed with the organic matrix. Nowadays, nanofillers are increasingly being used in various aspects of life, including the health care industry. They are useful in various domains of biomedical engineering. This chapter encapsulates the current understanding of the environmental, legal, health, and safety issues surrounding the use of nanofillers. The chapter begins by defining and classifying nanofillers and their applications in the construction, automotive, and consumer goods industries. It then reviews the literature on the environmental impact of these materials, including concerns about pollution and their effects on ecosystems. Further, the chapter examines legal and regulatory frameworks around nanofillers, including relevant international agreements and national regulations. Additionally, it reviews studies on the potential health and safety risks for workers and consumers and provides an overview of best practices for minimizing these risks. Lastly, the chapter provides a future outlook on the use of nanofillers and highlights areas in need of further research.