OECD Issues Two New Test Guidelines For Nanomaterials

The Organisation for Economic Co-operation and Development (OECD) published on July 2, 2026, two new Test Guidelines (TG) for nanomaterials:

• Test No. 127: Dustiness determination of materials containing nano‑objects and their aggregates and agglomerates: OECD developed the TG to address the need for standardized dustiness test methods applicable to powders containing granular and fibrous nano-objects and their aggregates and agglomerates (NOAA). The objective of the TG is to provide methods for measuring dustiness data that support regulatory decision-making processes. To ensure the robustness and applicability of the methods described, the TG includes comparisons between different approaches, highlighting their respective strengths and limitations.

• Test No. 322: Determination of the Solubility and Dissolution Rate of Nanomaterials for Environmental Fate Assessment: The TG states that nanomaterials “are specific forms of chemical substances and are thus covered by chemicals legislation in the OECD member countries.” The TG notes that regulatory requirements may include information on the nanomaterials’ intrinsic properties and/or identity. According to OECD, information on dissolution is generally needed to understand how nanomaterials behave under given conditions, and information on dissolution may be part of the regulatory information requirements and used for risk assessment. This TG is based on OECD TG No. 105: Water Solubility, the OECD Guidance Document on Transformation/Dissolution of Metals and Metal Compounds in Aqueous Media, and the OECD Guidance Document for the Testing of Dissolution and Dispersion Stability of Nanomaterials, and the Use of the Data for Further Environmental Testing and Assessment.