The timing for implementation has been communicated as part of the End of Consultation letter, issued on 19 April 2023 (link). As indicated there, some final clarifications on elements of the 51st, specifically related to feedback received during the Consultation, were pending, and were confirmed just before the Notification. This was to ensure to act based on the latest information at hand, including advice from RIFM as well as the Expert Panel for Fragrance Safety.
The notification of the 51st Amendment went out on 30 June 2023. All documentation related to the 51st Amendment is available on the IFRA website via the following links: IFRA Standards documentation (ifrafragrance.org) and IFRA Standards Library (ifrafragrance.org)