Hospitals have been told to ensure they have evacuation plans in place to deal with the risk of collapse-prone concrete.

NHS chiefs have been told to have procedures to cope with the failure of reinforced autoclaved aerated concrete (Raac), including for the “decant of patients and services”.

Managers in hospitals where Raac has already been confirmed have been told to ensure that management plans to deal with it are “sufficiently robust and being implemented”.

A letter sent from NHS England to trust chiefs said 27 sites had previously been identified as having Raac, with three of them having already eradicated the concrete.

The letter, from NHS England’s chief commercial officer Jacqui Rock and national director for emergency planning and incident response Dr Mike Prentice, called for trusts to make sure work to identify and manage Raac had been properly carried out.

But it added that plans for Raac collapses also needed to be kept up to date.

“Effective management of Raac significantly reduces associated risks; but does not completely eliminate them,” they said.

“Planning for Raac failure, including the decant of patients and services where Raac panels are present in clinical areas, is, therefore, part of business continuity planning for trusts where Raac is known to be present, or is potentially present.”

A regional evacuation plan was created and tested in the East of England region, with lessons from it shared across the country.

“We would recommend that all boards ensure that they are familiar with the learning from this exercise and that they are being incorporated into standard business continuity planning as a matter of good practice,” the NHS England letter said.

“This exercise is, however, essential for those organisations with known Raac, and should be done as a matter of priority if it has not already been completed.”

The NHS has been surveying sites and carrying out Raac mitigation work since 2019.

Almost £700 million has been allocated for mitigation work between 2021 and 2025, enabling trusts to put in place remediation and failsafe measures, with a goal of eradicating Raac from NHS buildings entirely by 2035.

Seven hospitals – Airedale, Queen Elizabeth King’s Lynn, Hinchingbrooke, Mid Cheshire Leighton, Frimley Park, West Suffolk Hospital and James Paget Hospital in Great Yarmouth – will be rebuilt due to Raac concerns.