EN 15276-2:2019

Fixed firefighting systems - Condensed aerosol extinguishing systems - Part 2: Design, installation and maintenance

This document specifies requirements and methods for the design, installation and maintenance of condensed aerosol extinguishing systems and the characteristics of the extinguishing media and types of fire for which it is a suitable extinguishing medium.
This document covers the use of condensed aerosol extinguishing systems for total flooding applications.
This document is not applicable to explosion suppression applications.
This document does not cover all legislative requirements. In certain countries specific national regulations apply and take precedence over this document. Users of this document are advised to inform themselves of the applicability or non-applicability for this document by their national responsible authorities.

Ortsfeste Brandbekämpfungsanlagen - Löschanlagen für kondensierte Aerosole - Teil 2: Planung, Installation und Instandhaltung

Dieses Dokument legt Anforderungen und Verfahren für die Planung, Installation und Instandhaltung von Löschanlagen mit konzentriertem Aerosol sowie die Eigenschaften der Löschmittel und die Arten der Brände, für die die Löschmittel geeignet sind, fest.
Dieses Dokument behandelt den Einsatz von Löschanlagen für konzentrierte Aerosole als Raumschutzanlagen.
Dieses Dokument gilt nicht für Anwendungen zur Explosionsunterdrückung.
Dieses Dokument deckt nicht alle gesetzlichen Anforderungen ab. In bestimmten Ländern gelten besondere nationale Vorschriften, die gegenüber diesem Dokument Vorrang haben. Den Anwendern dieses Dokuments wird geraten, sich über die Anwendbarkeit oder Nichtanwendbarkeit dieses Dokuments bei ihren nationalen zuständigen Behörden kundig zu machen.

Installations fixes de lutte contre l'incendie - Systèmes d'extinction à aérosol - Partie 2 : Calcul, installation et maintenance

Le présent document spécifie les exigences et les méthodes de conception, d’installation et de maintenance et sécurité des systèmes d’extinction à aérosol condensé et les caractéristiques des agents extincteurs, ainsi que les types de feux pour lesquels ils sont appropriés.
Le présent document couvre également l’utilisation des systèmes d’extinction à aérosol condensé pour des applications de noyage total.
Le présent document n’est pas applicable aux applications de suppression d’explosion.
Le présent document ne traite pas des exigences légales. Dans certains pays, des règlementations nationales spécifiques s’appliquent et prennent le pas sur le présent document. Il est conseillé aux utilisateurs du présent document de s’informer auprès des autorités nationales responsables de l’applicabilité ou de la non-applicabilité du présent document.

Vgrajeni gasilni sistemi - Sistemi za gašenje s kondenziranim aerosolom - 2. del: Načrtovanje, vgradnja in vzdrževanje

Ta evropski standard določa zahteve in metode za načrtovanje, vgradnjo in vzdrževanje sistemov za gašenje s kondenziranim aerosolom ter značilnosti sredstev za gašenje in vrst požarov, za katere je primerno sredstvo za gašenje.
Ta standard zajema uporabo sistemov za gašenje s kondenziranim aerosolom za popolno zapolnitev.
Ta standard se ne uporablja za zadušenje eksplozije.
V tem standardu niso obravnavane vse zakonodajne zahteve. V določenih državah veljajo posebni nacionalni predpisi, ki imajo prednost pred tem evropskim standardom. Uporabnikom tega evropskega standarda se svetuje, da se pri svojih nacionalnih odgovornih organih seznanijo z uporabnostjo oziroma neuporabnostjo tega evropskega standarda.

General Information

• Status: Published
• Publication Date: 26-Mar-2019
• Withdrawal Date: 29-Sep-2019
• ICS: 13.220.20 - Fire protection
• Technical Committee: CEN/TC 191 - Fixed firefighting systems
• Drafting Committee: CEN/TC 191/WG 6 - Gas extinguishing Systems and components
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 27-Mar-2019
• Due Date: 05-May-2019
• Completion Date: 27-Mar-2019
• Ref Project: SIST EN 15276-2:2019 - Fixed firefighting systems - Condensed aerosol extinguishing systems - Part 2: Design, installation and maintenance

Relations

• Replaces: CEN/TR 15276-2:2009 - Fixed firefighting systems - Condensed aerosol extinguishing systems - Part 2: Design, installation and maintenance
• Effective Date: 08-Jun-2022

Overview

EN 15276-2:2019 - "Fixed firefighting systems - Condensed aerosol extinguishing systems - Part 2: Design, installation and maintenance" (CEN) defines requirements and methods for the design, installation and maintenance of condensed aerosol extinguishing systems used for total flooding fire protection. The document covers the characteristics of aerosol extinguishing media and identifies the types of fire for which condensed aerosol is suitable. It is not applicable to explosion suppression applications and does not replace national legislation, which may take precedence.

Key topics and technical requirements

The standard provides comprehensive, practical guidance and requirements on:

• Use and limitations - suitable fire classes, extinguishing mechanisms, temperature and atmosphere constraints (e.g., potentially explosive atmospheres).
• Safety - hazards to personnel, safety precautions for occupiable and unoccupiable spaces, installer and user responsibilities, and electrical safety (earthing and electrostatic considerations).
• System design - protected-enclosure assessment, openings and ventilation, venting requirements, design application density and adjustments for leakage/ventilation, unit sizing and quantity of aerosol generators, hold time and discharge characteristics.
• Installation - placement and arrangement of aerosol generators, operating conditions, practical installation recommendations and system operation (automatic/manual).
• Detection, alarm and control - automatic detection, operating devices, control equipment types (electrical/pneumatic), alarms, time-delay and indicators.
• Commissioning and acceptance - enclosure and electrical checks, functional tests, documentation and completion statements.
• Inspection, maintenance and training - user inspection programmes, service schedules, maintenance responsibilities and personnel training.
• Annexes - working documents (normative) and informative guidance such as toxicity tests.

Practical applications

EN 15276-2:2019 is intended for total flooding protection of enclosed spaces where condensed aerosol extinguishing media are appropriate. Typical applications include protection of:

• enclosed technical rooms and cabinets (e.g., electrical switchgear, control rooms)
• server rooms and data centres
• machinery rooms and other enclosed hazards where a gaseous-like total flooding agent is required

The standard helps ensure systems are safe, effective and consistent with accepted engineering practice for condensed aerosol solutions.

Who should use this standard

• Fire-protection designers and engineers
• System manufacturers and aerosol generator suppliers
• Installers and commissioning agents
• Facility managers, maintenance staff and safety officers
• Regulatory authorities and third-party certifiers

Related standards

• Supersedes CEN/TR 15276-2:2009 (technical report revised into a normative standard)
• Users should check national regulations and other EN standards for complementary requirements (e.g., detection, electrical safety and building codes).

Keywords: EN 15276-2:2019, condensed aerosol extinguishing systems, fixed firefighting systems, design installation maintenance, total flooding, aerosol generators, system commissioning, inspection and maintenance.

Standards Content (Sample)

SLOVENSKI STANDARD
01-maj-2019
1DGRPHãþD
SIST-TP CEN/TR 15276-2:2009
9JUDMHQLJDVLOQLVLVWHPL6LVWHPL]DJDãHQMHVNRQGHQ]LUDQLPDHURVRORPGHO
1DþUWRYDQMHYJUDGQMDLQY]GUåHYDQMH
Fixed firefighting systems - Condensed aerosol extinguishing systems - Part 2: Design,
installation and maintenance
Ortsfeste Brandbekämpfungsanlagen - Löschanlagen für kondensierte Aerosole - Teil 2:
Planung, Installation und Instandhaltung
Installations fixes de lutte contre l'incendie - Systèmes d'extinction à aérosol - Partie 2:
Calcul, installation et maintenance
Ta slovenski standard je istoveten z: EN 15276-2:2019
ICS:
13.220.10 Gašenje požara Fire-fighting
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 15276-2
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2019
EUROPÄISCHE NORM
ICS 13.220.20 Supersedes CEN/TR 15276-2:2009
English Version
Fixed firefighting systems - Condensed aerosol
extinguishing systems - Part 2: Design, installation and
maintenance
Installations fixes de lutte contre l'incendie - Systèmes Ortsfeste Brandbekämpfungsanlagen - Löschanlagen
d'extinction à aérosol - Partie 2 : Calcul, installation et für kondensierte Aerosole - Teil 2: Planung, Installation
maintenance und Instandhaltung
This European Standard was approved by CEN on 6 January 2019.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 15276-2:2019 E
worldwide for CEN national Members.

Contents Page
European foreword . 5
Introduction . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Use and limitations . 11
4.1 General . 11
4.2 Extinguishants . 11
4.2.1 General . 11
4.2.2 Extinguishing mechanism . 12
4.3 Potentially explosive atmosphere . 12
4.4 Temperature limitations . 12
5 Safety . 12
5.1 Hazard to personnel . 12
5.2 Safety precautions . 13
5.2.1 General . 13
5.2.2 Unoccupiable areas . 15
5.2.3 Installer’s responsibility . 15
5.2.4 User’s responsibility . 15
5.3 Electrical hazards . 16
5.3.1 General . 16
5.3.2 Electrical earthing . 17
5.3.3 Electrostatic discharge . 17
6 System design . 17
6.1 General . 17
6.2 Specifications, plans and approvals . 18
6.3 Enclosures . 18
6.3.1 Protected enclosure . 18
6.3.2 Openings . 18
6.3.3 Unclosable openings . 18
6.3.4 Ventilation and services . 19
6.3.5 Venting requirements . 19
6.4 Design application density requirements . 19
6.5 Design application density adjustment . 20
6.5.1 Effects of ventilation . 20
6.5.2 Compensation for Leakage through enclosure openings . 20
6.6 Design application density . 20
6.7 Unit size and quantity of aerosol generators . 21
6.7.1 Aerosol generator size selection . 21
6.7.2 Quantity of aerosol generator . 22
6.8 Hold time . 22
6.9 System discharge . 23
6.9.1 Discharge time . 23
6.9.2 Extended discharge . 23
6.10 Plans . 23
7 System installation . 24
7.1 General . 24
7.2 Aerosol generator arrangement . 24
7.3 Operating conditions . 24
7.4 Installation recommendations . 25
7.5 System operation . 25
7.5.1 General . 25
7.5.2 Automatic operation . 25
7.5.3 Manual operation . 25
7.5.4 System isolate switch . 25
8 Detection, alarm and control systems . 26
8.1 General . 26
8.2 Automatic detection . 26
8.2.1 General . 26
8.2.2 Type/system tests for specific applications . 26
8.3 Operating devices . 28
8.3.1 General . 28
8.3.2 Automatic operation . 28
8.3.3 Manual operation . 28
8.4 Control equipment . 29
8.4.1 Electric control equipment . 29
8.4.2 Pneumatic control equipment . 29
8.4.3 Operating alarms and indicators . 29
8.4.4 Time delay device . 29
8.4.5 Control and indicating equipment . 30
9 Commissioning and acceptance . 30
9.1 General . 30
9.2 Tests . 30
9.2.1 General . 30
9.2.2 Enclosure check . 30
9.2.3 Review of mechanical components of condensed aerosol generators . 31
9.2.4 Review of enclosure integrity . 31
9.2.5 Review of electrical components . 31
9.2.6 Preliminary functional tests . 32
9.2.7 System functional operational test . 33
9.2.8 Remote monitoring operations (if applicable) . 33
9.2.9 Control panel primary power source . 33
9.3 Completion of functional tests . 33
9.4 Completion statement and documentation . 33
10 Inspection . 33
10.1 General . 33
10.1.1 Enclosures . 34
11 Maintenance . 34
11.1 General . 34
11.2 User’s programme of inspection . 35
11.3 Service schedule . 35
12 Training . 35
Annex A (normative) Working documents . 36
A.1 General . 36
A.2 Working documents . 36
Annex B (informative) Toxicity Tests . 37
Bibliography . 38

European foreword
This document (EN 15276-2:2019) has been prepared by Technical Committee CEN/TC 191 “Fixed
firefighting systems”, the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by September 2019, and conflicting national standards
shall be withdrawn at the latest by September 2019.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes CEN/TR 15276-2:2009.
In comparison with the previous edition CEN/TR 15276-2:2009, the following technical modifications
have been made:
— the Technical Report CEN/TR 15276-2:2009 has been revised and published as a standard;
— Normative references have been updated;
— Clause 3 "Terms and definitions" has been revised;
— Clause 4 "Use and limitations" has been revised;
— Clause 5 "Safety" has been revised;
— Clause 6 "System design" has been revised;
— 7.5.4 "System isolate switch" has been revised;
— Clause 8 "Detection, alarm and control systems" has been revised;
— Clause 9 "Commissioning and acceptance" has been revised;
— Clause 10 "Inspection" has been revised;
— Annex B "Toxicity Tests" has been added;
— the standard has been editorially revised.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Introduction
It has been assumed in the preparation of this document that the execution of its provisions is entrusted
to appropriately qualified and experienced people in the specification, design, installation, testing,
inspection, operation and maintenance of systems and equipment, for whose guidance it has been
prepared, and who can be expected to exercise a duty of care to avoid unnecessary release of
extinguishant.
Firefighting systems covered in this document are designed to provide a supply of fixed condensed
aerosol extinguishing medium to extinguish fire.
The requirements of this document are made in the light of the best technical data known at the time of
writing but, since a wide field is covered, it has been impracticable to consider every possible factor or
circumstance that might affect implementation of the requirements.
It is important that the fire protection of a building or plant is considered as a whole. Aerosol
extinguishant systems form only a part of the available facilities, but it should not be assumed that their
adoption necessarily removes the need to consider supplementary measures, such as the provision of
portable fire extinguishers or other mobile appliances for first aid or emergency use, or to deal with
special hazards.
Small scale fire tests, comparable with the test methods mentioned in this standard, indicate that
aerosol extinguishants can be recognized as effective media for the extinction of certain Class A fires
(solid surface burning fires) and Class B and Class C fires according to EN 2, but it should not be
forgotten, in the planning of comprehensive schemes, that there can be hazards for which these
mediums are not suitable, or that in certain circumstances or situations there can be dangers in their
use requiring special precautions.
Advice on these matters can be obtained from the appropriate manufacturer of the aerosol generators
or the extinguishing system. Information can also be sought from the appropriate fire authority, the
health and safety authorities and insurers. In addition, reference should be made as necessary to other
standards and statutory regulations.
It is essential that firefighting equipment, the enclosure and the protected occupancy is carefully
maintained and managed to ensure instant readiness when required and effectiveness of the protection.
Condensed aerosol can contain traces of toxic substances like those produced by a fire, and will obscure
vision like smoke from fire.
1 Scope
This document specifies requirements and methods for the design, installation and maintenance of
condensed aerosol extinguishing systems and the characteristics of the extinguishing media and types
of fire for which it is a suitable extinguishing medium.
This document covers the use of condensed aerosol extinguishing systems for total flooding
applications.
This document is not applicable to explosion suppression applications.
This document does not cover all legislative requirements. In certain countries specific national
regulations apply and take precedence over this document. Users of this document are advised to
inform themselves of the applicability or non-applicability for this document by their national
responsible authorities.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
CEN/TS 54-14, Fire detection and fire alarm systems — Part 14: Guidelines for planning, design,
installation, commissioning, use and maintenance
EN 15004-1:2019, Fixed firefighting systems — Gas extinguishing systems — Part 1: Design, installation
and maintenance (ISO 14520-1:2015, modified)
EN 15276-1:2019, Fixed firefighting systems — Condensed aerosol extinguishing systems — Part 1:
Requirements and test methods for components
EN 12094-1:2003, Fixed firefighting systems — Components for gas extinguishing systems — Part 1:
Requirements and test methods for electrical automatic control and delay devices
EN 12094-2, Fixed firefighting systems — Components for gas extinguishing systems — Part 2:
Requirements and test methods for non-electrical automatic control and delay devices
EN 12094-3, Fixed firefighting systems — Components for gas extinguishing systems — Part 3:
Requirements and test methods for manual triggering and stop devices
EN 12094-12, Fixed firefighting systems — Components for gas extinguishing systems — Part 12:
Requirements and test methods for pneumatic alarm devices
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 15276-1 and the following
apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1
activation mechanism
automatic or manual activation leading to the physical discharge of extinguishant
3.2
automatic
performing a function without the necessity of intentional human intervention
3.3
automatic switch
manual switch
means of converting the system from automatic to manual activation
3.4
clearance
3.4.1
electrical clearance
unobstructed air distance between the aerosol generator components and unenclosed or uninsulated
live electrical components not at ground potential
3.4.2
thermal clearance
air distance between a condensed aerosol generator and any structure or components sensitive to the
temperature developed by the generator
3.5
competent person
designated person, suitably trained, qualified by knowledge and practical experience and with the
necessary instructions to enable the required tests and examinations to be carried out
3.6
condensed aerosol
extinguishing medium consisting of finely divided solid particles and gaseous matter, these being
generated by a combustion process of a solid aerosol forming compound
3.7
condensed aerosol generator
non-pressurized device which, when activated, generates an aerosol and includes the mounting
brackets
3.8
control device
device which is able to control the sequence of events leading to the activation
3.9
coolant
heat absorbing medium or process
3.10
design application density
extinguishing density multiplied by the safety factor, required for system design purposes
Note 1 to entry: The design application density is expressed in grams per cubic metre.
Note 2 to entry: Extinguishing density and design application density have been introduced as an alternative to
extinguishing concentration and design concentration respectively as concentration of the actual aerosol cannot
be measured or even assessed in some cases (the discharged medium, apart from the condensed aerosol, can
contain products of the thermal decomposition of a chemical coolant).
3.11
design quantity
mass of solid aerosol-forming composition necessary to achieve the design application density in the
maximum protected volume of a specific risk
Note 1 to entry: The design quantity is expressed in grams.
3.12
discharge time
time from the generator activation to the end of its discharge
3.13
emergency hold device
device that prevents the electrical actuation of aerosol generators
3.14
extinguishing density
effective minimum mass of discharged extinguishant per unit of enclosure volume required to
extinguish fire involving specific fuel under defined experimental conditions
Note 1 to entry: Measured in g/m .
Note 2 to entry: Based upon the test using one or more specific aerosol generator(s) and excluding the safety
factor and including the efficiency of the generators
3.15
family of condensed generators
range of generators designed with the same solid compound, the same kind of cooling device, discharge
outlet, ignition device, layout and internal or external architecture with varying mass of solid compound
3.16
holding time
period of time during which an extinguishant is required to maintain at least the extinguishing density
to maintain even distribution throughout protected volume
3.17
hot work
grinding, welding, thermal or oxygen cutting or heating and other related heat-producing or spark-
producing operations
3.18
ignition device
any device which is intended to ignite the solid aerosol-forming compound
3.19
inspection
visual check to give reasonable assurance that the extinguishing system is fully charged and operable
Note 1 to entry: This is done by seeing that the system is in place, that it has not been activated or tampered
with, and that there is no obvious physical damage or condition to prevent operation.
3.20
location drawing
layout diagram of protected volume clearly indicating the as-installed location of all aerosol generators,
controls, maintenance isolate switch or emergency hold devices and associated components of the
systems
3.21
maintenance
combination of all technical, administrative and managerial actions during the life cycle of an item
intended to retain it in, or restore it to, a state in which it can perform the required function
Note 1 to entry: Technical maintenance actions include observation and analyses of the item state (e.g.
inspection, monitoring, testing, diagnosis, prognosis, etc.) and active maintenance actions (e.g. repair,
refurbishment).
3.22
manual
requiring intentional intervention to accomplish a function
3.23
monitoring
supervision of the operating integrity of an electrical, mechanical, pneumatic or hydraulic control
feature of a system
3.24
normally unoccupied area
area not normally occupied by people but which may be entered occasionally for brief periods
3.25
protected volume
volume enclosed by the building elements around the protected enclosure, minus the volume of any
permanent impermeable building element within the enclosure
3.26
release
physical discharge or emission of an aerosol as a consequence of the generator actuation
3.27
safety factor
multiplier of the extinguishing density to determine the aerosol design application density
3.28
solid aerosol-forming compound
mixture of oxidant, combustible component and technical admixtures producing fire extinguishing
aerosol upon activation
3.29
supplier
entity that is responsible for the product and is able to ensure that its quality is ensured
3.30
system isolate switch
key operated or dual mode switch manual device that prevents the electrical actuation of aerosol
generators
Note 1 to entry: The actuation of this device provides an indication of system isolation.
Note 2 to entry: The intent is to prevent the discharge of agent into the hazard area when the system isolation
switch device is activated.
3.31
thermal activation device
device, which automatically operates at a rated temperature and is arranged for the activation of the
solid aerosol-forming compound
3.32
total flooding system
firefighting system arranged to discharge extinguishant into an enclosed space to achieve the
appropriate design application density
3.33
unoccupiable area
area that cannot be occupied due to dimensional or other physical constraints
Note 1 to entry: Examples of unoccupiable areas are shallow voids and cabinets.
3.34
user
legal person, whom the system is designed for, and who is responsible for operation and to ensure the
consistency of performance as described by the supplier and to follow the legal regulations
4 Use and limitations
4.1 General
The design, installation, service and maintenance of aerosol generators shall be performed by those
competent persons in fire extinguishing system technology.
The hazards against which these aerosol generators offer protection, and any limitations on their use,
shall be contained in the system manufacturer’s design manual.
The total flooding use of aerosol generators is primarily for protection against hazards that are within
an enclosure that will permit to establish and maintain the appropriate design application density of
condensed aerosol for the required period of time to ensure an effective extinguishment.
Fire test protocols for class A fires covered by this standard have preburn times of 120 s for wood fuels
and 210 s for polymeric fuels. Aerosol generators systems are therefore appropriate for surface burning
fires where early detection and actuation is achieved.
Effects of agent particulate residue on sensitive equipment and other objects shall be considered when
using condensed aerosol extinguishing agents in spaces containing that type of equipment.
4.2 Extinguishants
4.2.1 General
The extinguishants referred to in this document are electrically non-conductive media.
The extinguishants and specialized system parameters are each covered individually in EN 15276-1 for
specific extinguishants which shall be used in conjunction with this document.
The extinguishants referred to in EN 15276-1 shall not be used on fires involving the following:
a) chemicals containing their own supply of oxygen, such as cellulose nitrate;
b) mixtures containing oxidizing materials, such as sodium chlorate or sodium nitrate;
c) chemicals capable of undergoing autothermal decomposition, such as some organic peroxides;
d) reactive metals (such as sodium, potassium, magnesium, titanium and zirconium), reactive
hydrides, or metal amides, some of which can react violently with the extinguishants;
e) oxidizing agents such as nitric oxides and fluorine;
f) pyrophoric materials such as white phosphorous or metallo-organic compounds.
The above list may not be exhaustive.
4.2.2 Extinguishing mechanism
Condensed aerosol is an extinguishing media consisting of finely divided solid particles (e.g. 40 % by
mass) typically based on alkali metal salts and gases (e.g. 60 % by mass), mainly comprised of nitrogen,
carbon dioxide and water vapor.
Aerosol extinguishes fires chemically, interfering with the flame chain reaction by removing the
reactive free radicals and physically, by cooling the seat of the fire. Both actions take place mainly on the
surface of the aerosol particles, and as such, the finer the particles the more effective the
extinguishment.
4.3 Potentially explosive atmosphere
Explosive atmosphere is a mixture of dangerous substances with air, under atmospheric conditions, in
the form of gases, vapors, mist or dust in which, after ignition has occurred, combustion spreads to the
entire unburned mixture.
Under certain conditions the potential for explosive atmospheres can exist. Areas where such potential
can exist are classified as hazardous. Condensed aerosols can be used in hazardous areas subject to the
manufacturer obtaining the specific listings and approvals for such areas from the appropriate
authorities.
Where aerosol generators are used in potentially explosive atmosphere, the compatibility of the
generator to the atmosphere for the determined lifetime should be assessed according to ATEX
directive 2014/34/EU [5].
4.4 Temperature limitations
All devices shall be designed for the service they will encounter and shall not readily be rendered
inoperative or susceptible to accidental operation.
Devices normally shall be designed to function properly from −20 °C to +50 °C, or marked to indicate
temperature limitations, or in accordance with manufacturers’ specifications which shall be marked on
the name-plate, or (where there is no name-plate) in the manufacturer’s instruction manual.
For condensed aerosols a special care shall be used to determine the maximum ambient temperature at
which the aerosol generator can be installed, without risk of actuation by temperature itself.
The condensed aerosol generators shall not be employed at less than the minimum thermal clearance
distances specified in the manufacturer’s instruction manual.
5 Safety
5.1 Hazard to personnel
Any hazard to personnel created by the actuation and discharge of the condensed aerosol generators
shall be considered in the design of the protection in particular with reference to the hazards associated
with particular extinguishants. When selecting a condensed aerosol extinguishant a careful
consideration shall be given to independent occupational health and safety data.
Adherence to this document does not remove the user’s statutory responsibility to comply with the
appropriate safety regulations.
The discharge of a condensed aerosol generator can create serious hazards for personnel in both the
protected area and areas to which it can migrate. These hazards include the following:
a) Reduced visibility: when activated, condensed aerosol generators depending on situation can
significantly reduce visibility both during and after discharge period.
b) Potential toxicity: when activated, condensed aerosol generators can produce toxic levels of gases
such as carbon monoxide, nitrogen oxides and ammonia, which are typical by-products of the
aerosol generating reaction. Actual concentrations of these by-products depend on the chemical
compositions of the solid aerosol-forming compound and coolant, engineering design of the aerosol
generators and conditions of the enclosure under protection. Maximum allowable exposure to a
design application density of the aerosol under conditions of a sealed enclosure shall be provided
for each agent by its manufacturer. Any possible adverse effects on humans that can be experienced
at the indicated allowable exposures shall be described. The information shall be supported by the
appropriate test results on chemical composition of the aerosol and its short term “acute” adverse
effects.
c) Thermal hazard: a condensed aerosol discharges at the elevated temperatures. Depending on the
intended application(s) of the aerosol system, the temperature at the reasonable minimum
clearance from the discharge outlet, as specified by the manufacturer of the aerosol generators,
shall not exceed 75 °C for persons, 200 °C for combustible material and 400 °C for construction
structures respectively. Immediately after discharge the aerosol generators can be hot, therefore,
protective gloves shall be worn before handling generators after discharge. If the protected area is
congested or contains temperature-sensitive equipment, it would be appropriate to select several
smaller units that require less minimum clearance although one large unit can be adequate in terms
of achieving the required design application density.
d) Turbulence: turbulence caused by high-velocity discharge from the nozzle can be enough to
dislodge substantial objects directly in its path, such as ceiling tiles and light fittings. Therefore,
tiles and light fittings shall be properly secured. Aerosol discharge can also cause enough general
turbulence to move unsecured paper and light objects.
In order to assess the potential human health effects manufactures should conduct the toxicity testing
for use described in Annex B.
Manufacturers shall specify characteristics such as particle sizes and particle size distribution of the
aerosol to allow an estimation of physiological effects when being inhaled.
5.2 Safety precautions
5.2.1 General
Reduced visibility during and after discharge together with potential toxicity restricts the use of a
condensed aerosol total flooding system to normally unoccupied and unoccupiable areas only. In any
proposed use of condensed aerosol where there is a possibility that people can enter the protected
enclosure or be close to the protected risk, suitable safeguards such as personnel training, warning
signs, pre-discharge alarms and system isolate switches shall be provided. Means of ventilation after
fire shall be readily available.
Unnecessary exposure to a condensed aerosol shall be avoided.
Following the use of a condensed aerosol, personnel shall not enter the protected area until it has been
thoroughly ventilated. Venting of the post-fire atmosphere shall be to an open-air area, where possible,
to prevent the inadvertent exposure of personnel to any combustion products of the fire and aerosol-
generating reaction. In case of fire involving unknown products it is imperative to check the
concentration of carbon monoxide and other potentially toxic gases before entering the premises.
Following a system discharge the aerosol that has settled shall be removed in accordance with the
manufacturer’s recommendations. Protective clothing including gloves and goggles shall be worn. A
respirator or mask can be required.
Venting in to an open-air area shall also prevent contamination/migration of extinguishant to other
areas than the protected area.
If there are no regulations available, the following minimum requirements should be taken (see
Table 1).
Table 1 — Minimum safety precautions
Emergency hold
Maximum factor Time delay device System Isolation switch
device
Unoccupiable areas Not Required Not Required Not Required
All other areas Required Required Required
NOTE The intent of this table is to avoid unnecessary exposure of occupants to the discharged
extinguishant. Factors such as the time to evacuate and the risk to the occupants by the fire should be considered
when determining the system discharge time delay. Where standards require other precautions, these should be
implemented.
WARNING — Any change to the enclosure volume, or addition or removal of contents that was not covered in the
original design will affect the design application density. In such cases, the system shall be recalculated to ensure
that the system with the new design application density is consistent with Table 1.
Standards have to be taken into account and following general safety aspects shall apply for areas
protected by the condensed aerosol total flooding systems and which are capable of being occupied:
a) Time delay devices:
1) extinguishing systems shall incorporate a pre-discharge alarm with a time delay sufficient to
allow personnel evacuation prior to discharge;
2) time delay devices shall be used only for personnel evacuation or to prepare the hazard area
for discharge.
b) system isolation switch and emergency hold devices at the entrance to the protected area where
required in accordance with Table 1;
NOTE Although emergency hold devices are not always required, they are essential in some situations,
particularly for some specific maintenance functions.
c) thermal automatic activation device shall not be used in normally unoccupied areas;
d) exit routes which shall be kept clear at all times, and emergency lighting and adequate direction
signs to minimize travel distances;
e) outward-swinging self-closing doors which can be opened from the inside, including when locked
from the outside;
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