SIST EN ISO 19353:2019

SLOVENSKI STANDARD
01-maj-2019
1DGRPHãþD
SIST EN ISO 19353:2016
Varnost strojev - Požarna varnost (ISO 19353:2019)
Safety of machinery - Fire prevention and fire protection (ISO 19353:2098)
Sicherheit von Maschinen - Vorbeugender und abwehrender Brandschutz (ISO
19353:2019)
Sécurité des machines - Prévention et protection contre l'incendie (ISO 19353:2019)
Ta slovenski standard je istoveten z: EN ISO 19353:2019
ICS:
13.110 Varnost strojev Safety of machinery
13.220.01 Varstvo pred požarom na Protection against fire in
splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 19353
EUROPEAN STANDARD
NORME EUROPÉENNE
February 2019
EUROPÄISCHE NORM
ICS 13.110 Supersedes EN ISO 19353:2016
English Version
Safety of machinery - Fire prevention and fire protection
(ISO 19353:2019)
Sécurité des machines - Prévention et protection Sicherheit von Maschinen - Vorbeugender und
contre l'incendie (ISO 19353:2019) abwehrender Brandschutz (ISO 19353:2019)
This European Standard was approved by CEN on 21 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 ISO 19353:2019 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Annex ZA (informative) Relationship between this European Standard and the essential
requirements of Directive 2006/42/EC aimed to be covered . 4

European foreword
This document (EN ISO 19353:2019) has been prepared by Technical Committee ISO/TC 199 "Safety of
machinery" in collaboration with Technical Committee CEN/TC 114 “Safety of machinery” the
secretariat of which is held by DIN.
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 August 2019, and conflicting national standards shall
be withdrawn at the latest by August 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 EN ISO 19353:2016.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive(s).
For the relationship with EU Directive(s) see informative Annex ZA, which is an integral part of this
document.
According to the CEN-CENELEC Internal Regulations, the national standards organizations 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.
Endorsement notice
The text of ISO 19353:2019 has been approved by CEN as EN ISO 19353:2019 without any modification.

Annex ZA
(informative)
Relationship between this European Standard and the essential
requirements of Directive 2006/42/EC aimed to be covered
This European Standard has been prepared under a Commission’s standardization request “M/396
Mandate to CEN and CENELEC for Standardisation in the field of machinery” to provide one voluntary
means of conforming to essential requirements of Directive 2006/42/EC of the European Parliament
and of the Council of 17 May 2006 on machinery, and amending Directive 95/16/EC (recast).
Once this standard is cited in the Official Journal of the European Union under that Directive,
compliance with the normative clauses of this standard given in Table ZA.1 confers, within the limits of
the scope of this standard, a presumption of conformity with the corresponding essential requirements
of that Directive and associated EFTA regulations.
Table ZA.1 — Correspondence between this European Standard and Annex I of Directive
2006/42/EC
Essential Requirement of Clause(s)/subclause(s) Remarks/Notes
Directive of this EN
Essential Requirement 1.5.6 Clauses 4 to 7 None
with regard to identification of
the protective measures
available for risk reduction
WARNING 1 — Presumption of conformity stays valid only as long as a reference to this European
Standard is maintained in the list published in the Official Journal of the European Union. Users of this
standard should consult frequently the latest list published in the Official Journal of the European
Union.
WARNING 2 — Other Union legislation may be applicable to the products falling within the scope of this
standard.
INTERNATIONAL ISO
STANDARD 19353
Third edition
2019-01
Safety of machinery — Fire prevention
and fire protection
Sécurité des machines — Prévention et protection contre l'incendie
Reference number
ISO 19353:2019(E)
©
ISO 2019
ISO 19353:2019(E)
© ISO 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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below or ISO’s member body in the country of the requester.
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Email: copyright@iso.org
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Published in Switzerland
ii © ISO 2019 – All rights reserved

ISO 19353:2019(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Fire hazards . 3
4.1 General . 3
4.2 Combustible materials . 4
4.3 Oxidizers . 4
4.4 Ignition sources . 4
5 Strategy for fire risk assessment and risk reduction . 5
5.1 General . 5
5.2 Determination of the limits of the machinery . 7
5.3 Identification of fire hazards . 7
5.4 Risk estimation . 8
5.5 Risk evaluation . 9
5.6 Risk reduction .10
5.6.1 General.10
5.6.2 Inherently safe design measures .10
5.6.3 Safeguarding .11
5.6.4 Complementary protective measures .11
6 Procedure for the selection of complementary protective measures .12
6.1 General .12
6.1.1 Use of the procedure .12
6.1.2 Determination of the residual risk level .13
6.1.3 Specification of requirements for the choice of fire detection and fire
suppression system .13
6.1.4 Specification of safety and performance requirements .13
6.1.5 Selection of system parts and suitable fire-extinguishing agent .13
6.1.6 Decision on the need for further complementary protective measures .13
6.1.7 Validation .13
6.2 Selection of the fire prevention and protection system in relation to the expected
risk level .13
6.2.1 General.13
6.2.2 Injury to persons.14
6.2.3 Safety considerations .14
6.2.4 Selection of system parts .14
6.2.5 Selection of fire-extinguishing agent .14
6.2.6 Validation .15
7 Information for use .15
Annex A (informative) Examples of machines and their typical fire-related hazards .17
Annex B (informative) Example of a methodology for selecting and qualifying a fire
detection and fire suppression system .18
Annex C (informative) Example for the design of a fire suppression system integrated in
machinery .35
Annex D (informative) Examples of ignition sources .36
Annex E (informative) Example for the risk assessment and risk reduction of a machining
centre for the machining of metallic materials .38
Bibliography .49
ISO 19353:2019(E)
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 ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
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 documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso
.org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 199, Safety of machinery.
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.
This third edition cancels and replaces the second edition (ISO 19353:2015), which has been technically
revised. It also incorporates the Amendment ISO 19353:2015/DAM 1:2017. The main changes compared
to the previous edition are as follows:
— old Annexes A and B have become Annexes D and A, respectively;
— an example of methodology for selecting and qualifying a fire detection and fire suppression system
has been added as new Annex B;
— old Annex D has been improved editorially and it has become Annex E;
— old Annex E on fire risk reduction measures has been deleted as well as references to it.
iv © ISO 2019 – All rights reserved

ISO 19353:2019(E)
Introduction
The safety of machinery against fire involves fire prevention and fire protection and fire-fighting. In
general, these include technical, structural, organizational and fire suppression measures. Effective fire
safety of machinery can require the implementation of a single measure or a combination of measures.
This document deals with the measures shown in Figure 1.
Figure 1 — Protective measures dealt with in ISO 19353
This document is a type-B standard as stated in ISO 12100.
This document is of relevance, in particular, for the following stakeholder groups representing the
market players with regard to machinery safety:
— machine manufacturers (small, medium and large enterprises);
— health and safety bodies (regulators, accident prevention organizations, market surveillance etc.).
Others can be affected by the level of machinery safety achieved with the means of the document by the
above-mentioned stakeholder groups:
— machine users/employers (small, medium and large enterprises);
— machine users/employees (e.g. trade unions, organizations for people with special needs);
— service providers, e. g. for maintenance (small, medium and large enterprises);
— consumers (in case of machinery intended for use by consumers).
The above-mentioned stakeholder groups have been given the possibility to participate at the drafting
process of this document.
ISO 19353:2019(E)
In addition, this document is intended for standardization bodies elaborating type-C standards.
The requirements of this document can be supplemented or modified by a type-C standard.
For machines which are covered by the scope of a type-C standard and which have been designed and
built according to the requirements of that standard, the requirements of that type-C standard take
precedence.
vi © ISO 2019 – All rights reserved

INTERNATIONAL STANDARD ISO 19353:2019(E)
Safety of machinery — Fire prevention and fire protection
1 Scope
This document specifies methods for identifying fire hazards resulting from machinery and for
performing a risk assessment.
It gives the basic concepts and methodology of protective measures for fire prevention and protection
to be taken during the design and construction of machinery. The measures consider the intended use
and reasonably foreseeable misuse of the machine.
It provides guidelines for consideration in reducing the risk of machinery fires to acceptable levels
through machine design, risk assessment and operator instructions.
This document is not applicable to:
— mobile machinery;
— machinery designed to contain controlled combustion processes (e.g. internal combustion engines,
furnaces), unless these processes can constitute the ignition source of a fire in other parts of the
machinery or outside of this;
— machinery used in potentially explosive atmospheres and explosion prevention and protection; and
— fire detection and suppression systems that are integrated in building fire safety systems.
It is also not applicable to machinery or machinery components manufactured before the date of its
publication.
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.
ISO 12100:2010, Safety of machinery — General principles for design — Risk assessment and risk reduction
ISO 13849-1, Safety of machinery — Safety-related parts of control systems — Part 1: General principles
for design
ISO 13943, Fire safety — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 12100, ISO 13943 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
ISO 19353:2019(E)
3.1
combustibility
property of a material capable of burning
Note 1 to entry: Accurate assessment of the combustibility characteristics of a material depends on the operating
conditions of the machinery and the form and physical state of the material (e.g. gaseous, liquid or solid; solids
chopped to form shavings or dust, or not).
Note 2 to entry: On the basis of their combustibility, materials can be classified into non-combustible, hardly
combustible, combustible and easily combustible materials. It is important not to mix up combustibility on the
one hand, and flammability or ignitability on the other. Consequently, flash points and ignition points do not
represent quantitative measures of combustibility.
3.2
extinguishing opening
port in the machine housing, closed with a plug or flap that can be safely accessed with an
extinguishing device
Note 1 to entry: An extinguishing device, e.g. a hose or lance, can be used.
3.3
fire
self-supporting combustion that can occur as controlled combustion or uncontrolled combustion
Note 1 to entry: Controlled combustion is deliberately arranged to provide an intended effect.
Note 2 to entry: Uncontrolled combustion is spreading uncontrolled in time and space.
Note 3 to entry: In the case of a combustion control failure, controlled combustion can lead to uncontrolled
combustion.
3.4
fire-extinguishing agent
agent which is appropriate to extinguish fire (3.3) by cooling below ignition temperature and/or by
reducing the oxidizer level
Note 1 to entry: The extinguishing agent can be gaseous, liquid or solid. Common extinguishing agents include
water, carbon dioxide, nitrogen, argon, chemical powder or foam.
3.5
fire prevention
set of measures to prevent the outbreak of a fire (3.3) and/or to limit its effects
[SOURCE: ISO 8421-1:1987, 1.21, modified — The words “set of” has been added to the definition.]
3.6
fire protection
set of measures such as design features, systems, equipment, buildings or other structures to reduce
danger to persons and property by detecting, extinguishing or containing fires (3.3)
[SOURCE: ISO 8421-1:1987, 1.23, modified — The words “set of measures such as” have been added to
the definition.]
3.7
fire suppression system
technical system to fight a fire (3.3) and to reduce the damaging effects of flames and heat
Note 1 to entry: Additional devices can be required to extinguish the fire.
3.8
ignition energy
energy necessary to initiate combustion
2 © ISO 2019 – All rights reserved

ISO 19353:2019(E)
3.9
low evaporation metalworking fluid
low-emission metalworking fluid
metalworking fluid composed of low-evaporation base media and anti-mist additives
Note 1 to entry: Low-evaporation base media are base oils consisting of low-evaporation mineral oils, synthetic
esters and/or special liquids.
3.10
overheating
uncontrolled temperature increase
3.11
pre-fire alarm system
pre-fire detection
system that detects conditions that can lead to the potential onset of fire (3.3) and initiates a response
Note 1 to entry: A response can be a trigger of an alarm signal or can initiate an automatic reaction.
Note 2 to entry: Sensors for these systems can detect heat due to friction, hot surfaces, loss of inerting, abnormal
changes of gas concentrations, failure of lubrication or cooling supply, etc.
Note 3 to entry: A fire alarm system is understood to be a system that, by the use of sensors, detects the onset of
fire and initiates a response. Sensors can be designed to detect smoke, combustion gases, heat or flames.
3.12
required performance level
PL
r
performance level (PL) applied in order to achieve the required risk reduction for each safety function
[SOURCE: ISO 13849-1:2015, 3.1.24, modified — Note 1 to entry has been deleted.]
3.13
self-ignition
spontaneous ignition resulting from self-heating
4 Fire hazards
4.1 General
A fire hazard occurs if combustible materials (fuel), oxidizer (oxygen) and ignition energy (heat) are
available in sufficient quantities at the same place and at the same time. A fire is an interaction of these
three components in the form of an uninhibited chemical reaction (see Figure 2).
A fire can be prevented or suppressed by controlling or removing one or more of the components of the
fire tetrahedron.
Certain materials are inherently unstable, extraordinary oxidizers or capable of self-heating. This
affects the fire hazard.
Variation in oxygen concentration (e.g. oxygen enrichment) can also affect the fire hazard.
The fire hazard can arise from the material processed, used or released by the machinery, from
materials in the vicinity of the machinery, or from materials used in the construction of the machinery.
NOTE An explosion hazard can exist in addition to the fire hazard.
ISO 19353:2019(E)
Key
1 heat 3 fuel
2 oxygen 4 uninhibited chemical chain reaction
Figure 2 — Fire tetrahedron
4.2 Combustible materials
It shall be determined whether combustible materials exist or can exist and in what quantity and
distribution. Combustible materials can occur as solids, liquids or gases.
The ease of combustion of materials is affected by the size, shape and deposition of the materials. For
example, small pieces of a material loosely collected together can be more easily ignited than a large
piece of that material. Also, the combination of materials can have an influence on the ignitability and
the burning behaviour.
Consideration shall be given as to whether the properties of the materials can change over time or with
use. Such changes can include the possibility of decomposition of the material releasing combustible
gases and vapours. This can lead to an increased fire hazard.
4.3 Oxidizers
In assessing the fire hazard, the existence and quantity of fire-supporting substances, e.g. oxygen-
producing substances, and the probability of their occurrence shall be determined. The most common
oxidizer is air. But there are other oxidizers that support combustion, e.g. potassium nitrate (KNO ),
potassium permanganate (KMnO ), perchloric acid (HClO ), hydrogen peroxide (H O ) and nitrous
4 4 2 2
oxide (N O).
4.4 Ignition sources
It shall be determined which ignition sources exist or can occur.
Possible ignition sources can arise due to the influence of:
a) heat energy;
b) electrical energy;
c) mechanical energy; and/or
d) chemical energy.
NOTE See Annex A for examples of machines and their typical fire related hazards and Annex D for examples
of ignition sources.
4 © ISO 2019 – All rights reserved

ISO 19353:2019(E)
5 Strategy for fire risk assessment and risk reduction
5.1 General
Fire risk assessment comprises a series of logical steps that allow systematic examination of fire
hazards according to the procedures outlined in ISO 12100. Fire risk assessment includes the following
sequential phases:
a) fire risk analysis, comprising:
1) determination of the limits of the machinery (see 5.2);
2) identification of fire hazards (see 5.3);
3) risk estimation (see 5.4);
b) risk evaluation.
When deemed necessary, risk evaluation is followed by risk reduction.
In planning fire prevention and protection measures, normal operating conditions – including start-
up and standstill procedures, possible technical failures and reasonably foreseeable misuse – shall be
taken into account.
The fire risk assessment and risk reduction shall be repeated as an iterative process until the risk
of a fire occurrence has been adequately reduced. Risk analysis judgements shall be supported by a
qualitative or, where appropriate, quantitative estimate of the risk associated with the hazards present
on the machinery. See Figure 3.
NOTE See Annex E for an example for the risk assessment and risk reduction of a machining centre for the
machining of metallic materials.
ISO 19353:2019(E)
Key
a
The first time the question is asked, it is answered by the result of the initial risk assessment.
b
If the applied risk reduction generates other hazards than fire hazards, risk reduction methods according to
ISO 12100 shall be applied.
Figure 3 — Schematic representation of fire risk reduction process including iterative three-
step method (adopted from ISO 12100)
6 © ISO 2019 – All rights reserved

ISO 19353:2019(E)
5.2 Determination of the limits of the machinery
Risk assessment shall include determination of the limits of the machinery, taking into account the
phases of the machinery life that can involve fire hazards.
Examples of machine limits that are useful in fire risk assessment are as follows:
— intended use and reasonably foreseeable misuse of the machine;
— properties of materials processed by the machine;
— machine operating modes;
— anticipated levels of training, experience or ability of the machine operators, maintenance personnel,
and where appropriate the general public;
— the level of awareness of fire hazards by those persons likely to be exposed to the fire hazards;
— the anticipated life of the machine and its components and the impact of ageing with respect to
creation of fire hazards;
— recommended service intervals;
— housekeeping and level of cleanliness as potential contributors to a fire hazard;
— the environment in which the machine is expected to be operated (e.g. dry, dusty, humid, hot, cold
conditions).
5.3 Identification of fire hazards
Following the determination of the limits of the machinery, reasonably foreseeable fire hazards shall be
identified, taking into consideration the phases of machinery life in which a fire hazard can be present.
NOTE See Clause 4 for a general discussion on the nature of fire hazards.
All reasonably foreseeable fire hazards associated with the various uses of the machine shall be
identified. The hazard can be identified according to the fire loads and ignition sources (see Figure 4).
For the determination of fire scenarios according to fire loads and ignition sources and for an
estimation of the fire risk, the procedures outlined in ISO 12100 shall be followed. The procedure
provides a sequence of logical steps allowing systematic examination of the fire hazards arising from
the machinery and/or the work process (see Figure 3).
Identification of fire hazards shall include the following steps:
— identification of intended and reasonably foreseeable operating conditions;
— identification of combustible and/or flammable materials that are related to the fire hazard (all
materials involved in the machine and process, including raw and process materials);
— evaluation of their ignitability, flammability, combustibility, fire supporting effect and toxic issues;
— estimation of the fire load based on the main combustible materials (fuel);
— identification of all possible ignition sources (e.g. heat) that can contribute to an ignition event;
— identification of fire scenarios according to fire loads and ignition sources: all reasonably foreseeable
scenarios that can lead to an ignition of the combustible and flammable materials, including
scenarios brought about by human errors such as exchange of substances, improper operation of
the machine, or improper maintenance.
ISO 19353:2019(E)
Figure 4 — Identification of significant fire hazards
5.4 Risk estimation
Once the fire hazards (fire scenarios) have been identified, the risk of occurrence of a fire shall be
determined by estimation. Risk estimation provides information required for the risk evaluation, which
in turn allows judgements to be made about whether or not risk reduction is required. Risk estimation
depends on the existence of a fire hazard, the frequency at which the machine is exposed to the fire hazard,
the probability of a fire occurring once exposure to hazard is present and the degree of possible harm.
The risk related to the fire hazard is a function of the severity of harm that can result from the fire
hazard and the probability of occurrence of that harm. The risk graph given in Figure 5 provides
guidance for risk estimation.
NOTE Methodology equivalent to Figure 5 can be used (see ISO/TR 14121-2).
8 © ISO 2019 – All rights reserved

ISO 19353:2019(E)
Key
Risk parameters:
S1 slight severity of injury (normally reversible)
S2 serious severity of injury (normally irreversible or death)
F1 frequency: seldom to less often and/or short exposure time to hazard
F2 frequency: often to continuous and/or long exposure time to hazard
P1 possibility of avoiding hazard or limiting harm given under specific conditions
P2 avoiding hazard or limiting harm scarcely possible
Figure 5 — Estimation of the risk level
Analysis of fire risks shall include consideration of the following elements:
— the frequency that the machine is exposed to the fire hazard;
— information for use regarding fire preventive measures (e.g. operating instructions, signs on the
machine);
— the likelihood that the machine operator will recognize a fire hazard and take intervention steps to
eliminate or reduce the possibility of a fire;
— the likelihood that once an ignition takes place the fire can be detected by the operator or a sensor
at an early stage;
— the extent of machine damage;
— the potential for operator or bystander injury and the most likely severity of such injury;
— the level of training of the operator with respect to fire hazard awareness and fire prevention
practices.
5.5 Risk evaluation
After risk estimation has been completed, risk evaluation shall be carried out to determine if risk
reduction is required. If risk reduction is required, then appropriate protective measures shall be
selected and applied.
ISO 19353:2019(E)
The adequacy of the risk reduction shall be determined after applying the technical fire prevention and
protection measures stated in 5.6.
NOTE See also the “three-step method” given in ISO 12100:2010, Clause 6.
5.6 Risk reduction
5.6.1 General
If risk reduction measures are required, it shall be decided which protective measures shall be taken to
reduce the risk of fire and/or to limit the effects of a fire.
After each protective measure is taken to reduce the risk of fire, a risk analysis shall be performed
again until the machine is safe following the process given in ISO 12100.
Fire prevention and protection measures do not cover the overall risk at the machinery in question,
and therefore care shall be taken to ensure that the protective measures applied do not create and/or
increase other fire risks.
Adequate risk reduction is achieved when:
— all operating conditions and intervention procedures have been considered;
— the risk of fire has been eliminated or reduced to the lowest acceptable level;
— any new fire risks introduced by the protective measures have been properly addressed;
— protective measures are compatible with one another; and
— the protective measures do not adversely affect the operator’s working conditions or impede the
function of the machine.
The objective of risk reduction can be achieved by applying fire prevention and protection measures as
protective measures comprising, in order of priority, the following:
a) inherently safe design measures (see 5.6.2);
b) safeguarding (see 5.6.3);
c) complementary protective measures (see 5.6.4 and 6.1);
d) information for use (see Clause 7).
All protective measures to reach this objective shall be applied in the sequence given in 5.6.2 to 5.6.4,
referred to as the “three-step method” (see also ISO 12100:2010, Clause 6).
5.6.2 Inherently safe design measures
5.6.2.1 The elimination or reduction of the risk of fire shall be primarily achieved by inherently safe
design measures, as shown in 5.6.2.2 to 5.6.2.6.
5.6.2.2 Minimal use of combustible materials in the construction of a machine.
The selection of the materials shall be carried out according to the risk analysis (see 5.2 to 5.4). In case
non-combustible materials are not applicable, self-extinguishing materials and fire-protected materials
should be used.
NOTE Such materials can be classified as per EN 13501–1 as class A1, class A2 or class B.
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ISO 19353:2019(E)
5.6.2.3 Minimal use of flammable fluids or lubricants.
The selection of fluids shall be carried out according to the risk analysis (see 5.2 to 5.4) taking into
account the combustion and ignition properties of the process fluids used.
NOTE Data for non-water-miscible metalworking fluids to perform risk analysis are shown in Table E.1 as an
example.
5.6.2.4 Competent ignition sources.
The risk analysis shall include machine operation or process deviations that might lead to the generation
of competent ignition sources. It shall be identified how such deviations are detected and/or controlled.
5.6.2.5 Use of materials in the construction of a machine that eliminate or minimize an adverse
interaction with the materials produced by or used by the machine.
5.6.2.6 Machine design that shall avoid aggregation of combustible or fire supporting concentrations,
or accumulations of raw material, intermediate product or finished product that exceed the amount
required for normal operation of the machine.
If applicable, inclusion of information in the instruction manual regarding steps to be taken by the user
to reduce or prevent the onset of fire, see Clause 7.
5.6.3 Safeguarding
When it is not possible to eliminate hazards or sufficiently reduce risks by inherently safe design
measures, consideration shall then be given to safeguarding to prevent persons from being exposed to
the hazards.
Safeguarding comprises the following:
a) limitation of the effects of fire (e.g. flames, heat and smoke), for example by shielding or enclosure
of the machine to eliminate or minimize the risk of injury to persons and/or damage to property;
b) containment or evacuation of hazardous components (e.g. dust, heat, smoke, toxicity);
c) installation of measures against flame ejection and hot gases through openings of the machine (e.g.
labyrinths, door gaps, opening for workpiece loading, see E.3.8.1.2).
The required performance level (PL ) of a safety-related part of a control system necessary for a safety
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function shall be determined according to ISO 13849-1.
5.6.4 Complementary protective measures
5.6.4.1 General
When inherently safe design measures and safeguarding do not reduce the risk of fire adequately,
further risk reduction shall be achieved by applying complementary protective measures. The
procedure to select the complementary protective measures is set out in detail in Clause 6.
Preference shall be given to integrated fire detection and fire suppression systems.
5.6.4.2 Integrated fire detection and fire suppression systems
Integrated fire detection and fire suppression systems include devices for fire detection, control, alarm
and extinguishing.
The control of the integrated fire detection and fire suppression systems shall be implemented
according to ISO 13849-1.
ISO 19353:2019(E)
The system shall include at least one safety function, for example, for:
a) the detection of a fire;
b) the corresponding signal processing; and
c) the activation of adequate measures (e.g. activation of fire suppression and/or fire alarm).
Depending on the risk analysis, the necessary safety function(s) and corresponding required
performance level (PL ) shall be defined.
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NOTE 1 An example for the design of a fire suppression system integrated in machinery is given in Annex C.
NOTE 2 An exemplary list of safety functions for machining centres for the machining of metallic materials is
given in Table E.2.
The extent of fire damage essentially depends on the fire load, the fire spreading and duration of
the fire. The fire should be detected as soon as possible and the extinguishing procedure should be
initiated with the minimum of delay following fire detection. If persons can be endangered by the use
of a hazardous fire-extinguishing agent (e.g. carbon dioxide, nitrogen) due regard
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