The OECD has published two guidance documents for the testing of manufactured nanomaterials.

● Guidance 318: covers the testing of dissolution and dispersion stability of nanomaterials, and the use of the data for further environmental testing and assessment.

● Guidance 317: provides guidance for aquatic, including sediment, ecotoxicity testing of manufactured nanomaterials for determining their hazard.
Both documents are applicable for testing under the REACH Regulation and can be used to cover specific information requirements for nanomaterials that entered into force on 1 January 2020.

A full list of accepted test methods relevant to address REACH information requirements for nanoforms is available on the EU nanomaterials observatory.

Reference: https://euon.echa.europa.eu/reach-test-methods-for-nanomaterials