The European Chemicals Agency (ECHA) announced on December 3, 2019, that it has developed a new Appendix for nanoforms applicable to the Guidance on Registration and Substance Identification.  According to ECHA, it aligns ECHA’s guidance with the amended annexes of the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) regulation that will apply to nanomaterials and enter into force on January 1, 2020.  The new guidance document explains the term nanoform, provides advice on how to build and justify sets of nanoforms, and explains what characterization information needs to be reported.  ECHA updated the Appendix for nanoforms applicable to the Guidance on QSARs and Grouping of Chemicals to reflect the advice of the new guidance document.  ECHA states that the update also clarifies the differences between creating a set of nanoforms and read-across for justifying the use of hazard data between different (sets of) nanoforms of a substance.  ECHA notes that it will keep updating the existing guidance for human health and environmental information requirements during 2020.  To support potential registrants in meeting the new information requirements, an updated overview of available test guidelines and other recognized methods and standards is available on the European Union Observatory for Nanomaterials (EUON)