The OECD has opened a public consultation on draft guidance for in vitro testing methods that assess the intestinal fate of orally ingested nanomaterials, running from 29 September to 10 November 2025. The guidance document addresses critical aspects of nanomaterial behavior in the human digestive system, including simulation of gastrointestinal digestion and interactions with the intestinal mucosa.

The draft guidance aims to standardize testing approaches for predicting how nano- and microparticles dissolve, transform, and are absorbed following oral ingestion. By establishing harmonized methods, the document will support regulatory agencies in conducting more accurate toxicokinetic assessments and exposure evaluations for nanomaterials that enter the body through ingestion.

This consultation represents an important step toward developing internationally recognized testing protocols that can improve safety assessments of nanomaterials in food, pharmaceuticals, and consumer products. Stakeholders from industry, academia, and regulatory bodies are invited to review the draft guidance and provide feedback during the consultation period.

More information on the OECD public consultation page.