During the last decade, the environmental risk assessment (ERA) of nanomaterials (NMs) has advanced towards a better understanding the differential methodologies and tools needed to evaluate their behaviour and potential impact. Despite being regulated by agencies devoted to chemicals, such as the European Chemicals Agency (ECHA), NMs present inherent characteristics that make implementing the gold standard methods for quantification and ecotoxicology tests initially designed for chemicals challenging. In this chapter, we revise the advances of the last 10 years in knowledge, methods and instruments to assess the potential risks of NMs, including nanoplastics, in the environment: the development of specific standards and guidelines, analytical methods and instruments, high-throughput tests, frameworks for grouping and read-across or the exponential increase on the development of NM-specific computational tools and in silico models. We also identify the new trends in NM development, as the materials developed today can be the new contaminants tomorrow and stress the importance of the recently released safe and sustainable by-design framework for NMs. Finally, we will revise the current gaps that the researchers, regulatory bodies, and industry must fill to attain a good framework for NMs ERA.