ISO 7240-1:2025

International
Standard
ISO 7240-1
Fourth edition
Fire detection and alarm systems —
2025-10
Part 1:
General and definitions
Systèmes de détection et d'alarme d'incendie —
Partie 1: Généralités et définitions
Reference number
© ISO 2025
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Functions .13
Annex A (informative) Functions, examples and relevant standards .15
Bibliography . 17

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
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The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
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This document was prepared by Technical Committee ISO/TC 21, Equipment for fire protection and fire
fighting, Subcommittee SC 3, Fire detection and alarm systems.
This fourth edition cancels and replaces the third edition (ISO 7240-1:2014), which has been technically
revised.
The main changes are as follows:
— wording of the scope has been simplified to improve readability;
— editorial corrections have been made to bring the document in line with current ISO drafting rules;
— some definitions (e.g. access level, detachable detector, multipoint detector, zone, etc.) have been changed
or added to bring them in line with other parts of ISO 7240 or EN 54-1:2021;
— some terms have been deleted (e.g. alarm, alarm indication, alphanumeric display, combustion gas
detector, etc.) because they were used as general meanings or not used in the ISO 7240 series.
A list of all parts in the ISO 7240 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
The ISO 7240 series specifies components of fire detection and alarm systems, requirements for their
interconnection and installation and the performance, testing, and servicing of parts or of complete systems.
It provides:
— signals to organizations having authority to respond to fire alarms, and
— signals to initiate the operation of fire protection equipment and other systems.
A fire detection and alarm system may be activated by automatic detection devices or by manual operation
and should fulfil its functions without errors or omissions, including:
— detecting quickly enough to fulfil its intended function,
— reliably transmitting the detection signal to the control and indicating equipment and, if applicable, the
fire alarm receiving station,
— translating the detection signal into a clear alarm signal that will attract the attention of occupants in an
immediate and unmistakable way,
— remaining insensitive to phenomena other than those which its function is to detect, and
— signalling immediately and clearly any supervised fault that can potentially jeopardize the correct
performance of the fire detection and alarm system.
A fire detection and alarm system should not:
— be adversely affected by any other systems whether associated with it, or not.
— be rendered partially or totally inoperative by the fire or the phenomenon which it is designed to detect
before the fire or phenomenon has been detected.
The ISO 7240 series applies to fire detection and alarm systems installed in and around buildings. It can be
used as a basis for the assessment of systems for other purposes (e.g. mines, ships) but the specific nature of
each application should be considered before use. Additional performance and environmental tests can be
necessary. It does not preclude the manufacture or use of systems having special characteristics suitable for
protection of specific risks against specific hazards.
A fire detection and alarm system is required to function satisfactorily not only in the event of fire, but
also during and after exposure to conditions likely to be met in practice such as corrosion, vibration, direct
impact, indirect shock, and electromagnetic interference. Some tests specified are intended to assess the
performance of system components under such conditions.
The performance of components of fire detection and alarm systems is assessed from the results obtained
in the specific tests. The compliance of a component with the relevant part of ISO 7240 does not necessarily
ensure that the component will function correctly when connected with another component also conforming
to the relevant part of ISO 7240 (e.g. a fire detector with fire detection control and indicating equipment),
unless both components have been assessed together as conforming to the requirements for a fire detection
and alarm system. Requirements for the assessment of the compatibility of system components are specified
in ISO 7240-13. Satisfactory operation of an installed system should be confirmed by testing after completion
of the installation (see ISO 7240-14 and ISO 7240-19). The ISO 7240 series is not intended to place any other
restrictions on the design and construction of such components.
If appropriate, the ISO 7240 series can be applied to the detection part of extinguishing systems, excluding
sprinkler heads, although the sensitivity requirements are not necessarily applicable in every instance.

v
International Standard ISO 7240-1:2025(en)
Fire detection and alarm systems —
Part 1:
General and definitions
1 Scope
This document defines the terms and definitions that are used throughout the ISO 7240 series of standards.
It describes the functions carried out by the components of a fire detection and alarm systems (FDAS).
This document applies to FDAS installed in and around buildings.
This document does not cover devices which are covered in ISO 12239.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
A-weighted sound pressure level
sound pressure level expressed in dB(a), which is 20 times the logarithm to base ten of the ratio of the
A-weighted sound pressure to the reference pressure of 20 μPa at 1 kHz
Note 1 to entry: The A-weighting characteristics are given in IEC 61672–1.
3.2
access level
one of several states of equipment in which selected:
— controls can be operated;
— manual operations can be carried out;
— indications are visible; and/or
— information can be obtained and changed
3.3
addressable device
device that can be individually identified at the control and indicating equipment (3.22)
3.4
addressable point
point (3.83) which can be individually identified at the control and indicating equipment (3.22)

3.5
aerosol density
smoke density
amount of particulates per volume as described operationally by one of two parameters:
— m (3.71), an absorbance index, used in the testing of smoke detectors (3.94) using scattered or
transmitted light;
— y (3.109), a dimensionless variable, used in the testing of smoke detectors using ionization
Note 1 to entry: These parameters are not concentrations in the strict sense, but represent values that are proportional
to the concentration and have been shown to function in place of a true concentration value for the purposes of tests.
3.6
alarm concept
description of the design of the fire detection and alarm system (3.48) with a justification of the choice of
audible and visual warning devices providing warning signals (3.107) to occupants,
Note 1 to entry: Note1 to entry: Includes the alarm organisation, fire receiving station and measures to be taken in
case of alarm
3.7
alert signal
audible signal conforming to ISO 7731 or visual signal or a combination of audible and visual signals that call
attention to the possibility of a hazardous or dangerous situation
3.8
analogue detector
detector that gives an output signal representing the value of the sensed phenomenon
Note 1 to entry: This may be a true analogue signal or a digitally encoded equivalent of the sensed value.
3.9
ancillary equipment
equipment that supports fire detection and fire alarm functions, and that not currently defined in ISO 7240
EXAMPLE Ancillary input or output equipment (see Figure 1, item N).
3.10
ancillary function
action performed by equipment not related to fire detection or fire alarm system (3.45)
Note 1 to entry: See Figure 1, item O.
3.11
aspirating smoke detector
smoke detector (3.94), in which air and aerosols are drawn through a sampling device and carried to one or
more smoke-sensing elements by an integral aspirator (e.g. fan or pump)
Note 1 to entry: Each smoke-sensing element may contain more than one sensor exposed to the same smoke sample.
3.12
audible alarm device
AAD
DEPRECATED: fire alarm sounders
component (3.20) intended to signal an audible warning of fire to the occupants of a building
Note 1 to entry: See Figure 1, item C and item P.
3.13
building management system
facilities used to monitor, control and manage equipment installed in a building for either comfort, safety or
security, or all of these purposes

3.14
cabinet
housing that affords a degree of mechanical protection and robustness to its constituent parts and
subassemblies
3.15
certification
third-party attestation related to an object of conformity assessment, with the exception of accreditation
[SOURCE: ISO/IEC 17000:2020, 7.6]
3.16
combination detector
detector incorporating within one mechanical housing more than one fire sensor with each sensor
independently signalling an alarm condition
3.17
commissioning
process that verifies the installed equipment or system meets the defined requirements
3.18
compatibility
ability of a component (3.20) of a fire detection and alarm system (3.48) to operate with
another component of the same FDAS
3.19
competent person
person who, in relation to the work undertaken, has the necessary knowledge, skill, and experience to
complete the work satisfactorily and without danger or injury to any person
3.20
component
device contained in one housing performing at least one or part of a function of a fire
detection and alarm system (3.48)
EXAMPLE Fire detectors (3.51), alarm devices, and control and indicating equipment (3.22) are components of an FDAS.
Note 1 to entry: Where a function is distributed in separate cabinets (3.14), each cabinet is considered as a separate
component.
3.21
configuration
structuring and interconnection of the hardware and software of a system for its intended application
[SOURCE: IEC 62425:2007, 3.1.8]
3.22
control and indicating equipment
CIE
equipment that is generally used for receiving signals, determining signal priority and routing, giving
audible and visible indication, and monitoring and warning of specified faults
Note 1 to entry: CIE that is used for detecting fire through detectors and manual call points is termed as fire detection
control and indicating equipment (3.49)
Note 2 to entry: CIE that is used to broadcast audible warning signals is termed as sound system control and indicating
equipment (3.97)
3.23
conventional detector
fire detector (3.51) which gives one of two output states relating to either normal condition or fire alarm
condition and indicates collective response as one of the points (3.83) in a fire detection zone (3.50) at an fire
detection control and indicating equipment (3.49)
Note 1 to entry: Some countries refer to conventional detector as non-addressable detector.
3.24
detachable detector
detector that is designed for removal of the head from its base
Note 1 to entry: The use of detachable detectors can assist during maintenance without disconnecting the fixed wiring.
3.25
detection circuit
transmission path (3.100) that connects points (3.83) to the fire detection control and indicating equipment (3.49)
3.26
detection concept
description of the design of the fire detection and alarm system (3.48) with a justification of the choice of
detectors, its sensitivity and its spacing
3.27
detection signal
signal from a detection device (see Figure 1, item A) to show that a fire has been detected
3.28
detector response
defined change of the status of a fire detector (3.51) after actuation of an alarm signal
3.29
earth fault
unwanted connection between earth potential and any part of the control and indicating equipment (3.22),
transmission paths (3.100) to the control and indicating equipment, or transmission paths between parts of
the control and indicating equipment
3.30
emergency detection system
application intended for the protection of life, property, or the environment such as
— fire detection and alarm system (3.48),
— gas detection system,
— intrusion and hold-up alarm,
— closed circuit television,
— access control, and
— manual call point (3.72).
3.31
emergency management plan
documented procedure that considers all aspects of the management of an emergency to ensure the safety
of building occupants
Note 1 to entry: The emergency management plan is likely to include the evacuation of building occupants, but under
certain circumstances, the retention of occupants in their current locations can be preferable.

3.32
end-of-line device
device, which may be inserted into the end of a transmission path (3.100) of a fire detection and alarm system
(3.48), to make monitoring of the integrity of the transmission path feasible
Note 1 to entry: An end-of-line device can be a physically separate device or it can be incorporated into another device
(e.g. end audible alarm device (3.12) on the line, detector or loudspeaker).
3.33
emergency microphone
microphone dedicated for use by a competent person (3.19) during the voice-alarm condition (3.106)
3.34
evacuation plan
part of the emergency management plan (3.31) dealing with the safe and orderly evacuation of building
occupants
3.35
evacuate signal
audible or visual signal or a combination of audible and visual signals conforming to ISO 8201 that means
“evacuate the building immediately”
3.36
fault warning routing equipment
equipment that routes a fault warning signal to a fault warning receiving station (3.37)
Note 1 to entry: See Figure 1, item J.
3.37
fault warning receiving station
centre from which the necessary corrective measures can be initiated on receipt of a fault signal
Note 1 to entry: See Figure 1, item K.
3.38
field
subdivision of a window (3.108)
3.39
final voltage
lowest recommended voltage to which a battery should be discharged
Note 1 to entry: The final voltage is specified by the battery manufacturer.
3.40
fire alarm and fault warning transmission system
system used for routing fire alarm and fault warning signals from fire detection and alarm system (3.48) to
fire alarm receiving stations (3.41) and fault warning receiving stations (3.37)
3.41
fire alarm receiving station
centre, on or remote from the protected premises, from which the necessary fire protection or firefighting
measures can be initiated at any time on receipt of a fire alarm signal (3.43)
Note 1 to entry: See Figure 1, item F.
3.42
fire alarm routing equipment
intermediate equipment which routes an alarm signal from fire detection control and indicating equipment
(3.49) to a fire alarm receiving station (3.41)
Note 1 to entry: See: Figure 1, item E.

3.43
fire alarm signal
signal, which may be electrical, mechanical, audible, visual, etc., to show that a hazard from fire exists in an area
Note 1 to entry: The signal may be local, addressed to the occupants of the area, or remote, addressed to other people
or organizations from whom assistance can potentially be required.
3.44
fire alarm signalling device
fire alarm device
equipment, not incorporated in the control and indicating equipment (3.22), that is used for warning persons
EXAMPLE audible alarm device (3.12), loudspeaker or visual alarm device (3.105)
Note 1 to entry: See Figure 1, item C and item P.
3.45
fire alarm system
DEPRECATED: sound system for emergency purposes
application consisting of:
— sound system control and indicating equipment (3.97),
— power supply equipment,
— loudspeakers,
— other equipment necessary for the operation of the system,
and interconnected by transmission paths (3.100)
3.46
fire alarm zone
DEPRECATED: emergency loudspeaker zone
subdivision of the premises composed of one or more acoustically distinguishable areas, such that the
occurrence of an emergency within it is indicated separately from any other subdivision
3.47
fire brigade panel
device connected to the fire detection control and indicating equipment (3.49) specifically designed for use by
the fire brigade
EXAMPLE Fire brigade control panel, fire brigade indicator panel.
3.48
fire detection and alarm system
FDAS
group of components (3.20), including control and indicating equipment (3.22), which, when arranged
in (a) specified conf
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