Key challenges for evaluation of the safety of engineered nanomaterials

The development of reliable and practical tools to ensure the safe and sustainable use of nanomaterials has not kept pace with the rapid commercialization of nanotechnology-enabled products. Here we present an overview of some of the current challenges and opportunities for the evaluation of the safety of engineered nanomaterials (ENM), based on input from an IUPAC (International Union of Pure and Applied Chemistry) sponsored workshop in Queretaro, Mexico. The workshop covered detection and characterization of ENM, their transformations in consumer products and the environment, current gaps in nanotoxicology methods and challenges for standardization and risk assessment. Key future research priorities include developing methods to detect and characterize ENM in complex matrices and determinations of their transformations in such environments. The extension of methods to more challenging materials such as complex or advanced nanomaterials and carbon-based materials is also needed. Furthermore, an increased availability of validated protocols and reference materials will be necessary to advance both nanosafety studies and material characterization. A focus on accurate dosimetry, appropriate control experiments and more realistic in vitro models will help to address current gaps in nanotoxicology. Finally, there is an urgent need for reliable data and improved data reporting guidelines, supported by computational modeling, in order to allow the development of grouping and read across methods.