Guidance Document for In Vitro Testing of the Intestinal Fate of Orally Ingested Nanomaterials

This document contains guidance on in vitro testing of the intestinal fate of orally ingested nanomaterials. The regulatory relevance of determining the intestinal fate of ingested nanomaterials (NMs) under conditions representative of the human digestion process to address the need for regulatory interventions on oral exposure to NMs was highlighted by several institutions in OECD member countries. The intestinal barrier is designated as a priority target for evaluation, including exposure assessment and hazard characterisation within risk assessment (RA) frameworks. Several non-animal approaches are now available to address these considerations within a regulatory context. The document describes physiological processes and in chemico methods for the digestion of nanomaterials in simulated gastro-intestinal fluids. It also describes state-of-the-art in vitro models to assess the intestinal barrier, key elements for nanomaterials uptake and translocation, analytical considerations, and guidance on data interpretation and reporting.