On January 12, 2018, the European Food Safety Authority (EFSA) opened a public consultation on its draft guidance for the risk assessment of nanoscience and nanotechnology applications in the food and feed chain. The guidance covers the relevant areas within EFSA’s remit, such as novel foods, food contact materials, food and feed additives, and pesticides. EFSA notes that the guidance takes account of scientific developments that have taken place since publication of the previous guidance in 2011, particularly studies that offer new insights into exposure assessment and hazard characterization of nanomaterials. The guidance considers potential future developments suggested in the scientific literature for nanoencapsulated delivery systems and nanocomposites in applications such as novel foods, food/feed additives, biocides, pesticides, and food contact materials. Therefore, EFSA states, the guidance has taken account of relevant new scientific studies that provide more insights to physicochemical properties, exposure assessment, and hazard characterization of nanomaterials. It specifically elaborates on physicochemical characterization of nanomaterials in terms of how to establish whether a material is a nanomaterial, the key parameters that should be measured, the methods and techniques that can be used for characterization of nanomaterials, and their determination in complex matrices. It also details the aspects relating to exposure assessment and hazard identification and characterization. In particular, according to EFSA, the guidance discusses nanospecific considerations relating to in vivo/in vitro toxicological studies and outlines a tiered framework for toxicological testing. Depending on the initial tier results, studies may be needed to investigate reproductive and developmental toxicity, immunotoxicity, allergenicity, neurotoxicity, effects on gut microbiome, and endocrine activity. The guidance touches upon the possible use of read across to fill data gaps, in vitro digestion, toxicokinetics, and genotoxicity, as well as general issues relating to in vitro testing of nanomaterials. The guidance also discusses the potential use of integrated testing strategies and the knowledge of modes/mechanisms of action. The guidance proposes approaches to risk characterization and uncertainty analysis, and provides recommendations for further research in this area. Comments are due March 4, 2018.