Delayed Egress Devices
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Issue/Revision Date / 01/11/2010 / Review Date / 26/03/2015 / Version / 4.0
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Background
This Note for Inspecting Officers provides guidance on the standards that are considered appropriate in respect to Delayed Egress Devices.
The Note aims to set general principles and to provide the reader with information as to which approved document or technical standard is considered by this Authority to be appropriate.
Information
Delayed egress devices are being fitted to 'Push Bar' fire exit doors in an attempt to reduce theft from premises. These devices prevent the door from being immediately available (for a preset period) and in doing so allows employees time to investigate.
Before Authority approval is given to install delayed egress devices on doors required for means of escape the responsible person should have carried out a risk assessment. They should have noted, in particular, the requirements made in the Regulatory Reform (Fire Safety) Order 2005, i.e.
Emergency doors shall not be so locked or fastened that they cannot be easily and immediately opened by any person who may require to use them in an emergency"
Delayed egress devices are not normally recommended for exit doors situated in areas which may create 'pinch' or 'crush' points, for example, at the foot of stairs.
Fire Safety Officers considering their appropriateness should assess whether the fitting of a device prejudices the safety of any ‘relevant person’.
The following control measures are normally considered necessary before approval is given, however, each door's suitability for the fitting of a delayed egress device must be assessed individually (i.e. site specific), and there should be no blanket approval.
Appropriate Control Measures
The locking device must consist of two metal plates hold together by electro-magnetic force.
The device is arranged to fail-safe (unlocked) when power to the unit is isolated.
The device is arranged to fail-safe if power to the device/building is cut off or interrupted. No independent battery back up to the device is to be allowed.
The premises should have an appropriate Automatic Fire Detection system (minimum L3 type) –Manual call points should be positioned next to all final fire exit doors from the building
The device is arranged to fail-safe to open on actuation of the fire alarm (by any type of sensor, for example, actuation of a call point, smoke detector, heat detector or sprinkler link relay).
Fire alarm 'Time Delay Units' or ‘Double-knock Actuations’ should not be allowed.
The maximum release delay will depend on the circumstances of the individual fire exit, but in the first instance a maximum delay of 15 seconds is suggested. For a 15 second delay to be approved it should be established that a fire is unlikely spread so fast that a fifteen second delay would place persons at serious risk.
Re-locking of the device is to be achieved only by a manual reset of the device at the door. Remote re-locking or automatic re-locking should not be allowed.
The device should be arranged to fail-safe to open if all power to the fire alarm system is lost. Battery back up for the fire alarm system is acceptable and the doors do not need to fail-safe to open whilst this supply is maintained, however, the fire alarm operation should not be prejudiced or the battery standby duration reduced to below that required for the fire alarm system.
Each door fitted with a device should have a clear notice of an adequate size (minimum A4) indicating that:
• An alarm will sound as soon as the opening bar is pushed.
• The door will unlock automatically after a delay of ? seconds after the bar has been pushed.
Fire exit doors fitted with delayed egress devices should be in the view of trained employees. A local alarm (with a distinct and different tone to that used for the fire alarm) should be able to call their attention to the door when the operating bar is pressed.
Further information
BS 7273-4 gives recommendations for the design, installation, commissioning and maintenance of electrical control arrangements for actuation of mechanisms that unlock, release or open doors in the event of fire.
It does not apply to the actual equipment that holds, releases, locks or unlocks the doors, or that facilitates the opening of powered sliding doors. However, recommendations are, where appropriate, given for the standards to which some of this equipment needs to conform.
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