This circular letter introduces NSI Technical Bulletin No. 0056 which describes the recently published BS 5839-6:2019+A1:2020. The main requirements introduced by the publication of the amendment 1 of BS 5839-6:2019 The main reason for the change and introduction of this new edition is to cover findings of clinical research that suggests that children may not be woken from their sleep by the sound produced by active fire alarm sounders. A note is added to BS 5839-6:2019+A1:2020 warning of the danger that children may sleep through a fire alarm. There is also a requirement for smoke detector manufacturers to include the same warning on product documentation. Implementation timescale for approved and applicant companies New applicant companies to NSI Fire Gold and Silver schemes will be audited against BS 5839-6:2019+A1:2020 with immediate effect and any Improvement Needs recorded against clauses of the Standard will have to be satisfactorily addressed before approval can be granted. How do I obtain a copy of BS 5839-6:2019+A1:2020? BS 5839-6:2019+A1:2020 is available as an outright individual purchase directly from the BSI or at a discounted rate from the NSI or, alternatively, as a download via the NSI approved company Standards on Subscription service. Questions or queries? If you have any questions or queries regarding the implementation of the change, please do not hesitate to contact me.