The European Commission has opened its long awaited <link http: ec.europa.eu info law better-regulation initiatives ares-2017-4513169 _blank>consultation on the revision of its Recommendation on the definition of nanomaterials. In 2011 the definition of nanomaterials was agreed to comprise substances with a content of at least 50% of particles or more with a size between 1nm-100nm. While it was originally planned to revise this definition in December 2014 this was delayed in order to take the third and final report from the Joint Research Centre into account.