SIST EN 60695-1-1:2000
(Main)Fire hazard testing -- Part 1-1: Guidance for assessing the fire hazard of electrotechnical products - General guidelines
Fire hazard testing -- Part 1-1: Guidance for assessing the fire hazard of electrotechnical products - General guidelines
Provides guidance for assessing the fire hazard of electrotechnical products and for the resulting development of fire hazard testing as related directly to harm to people, animals or property. Products, as defined in this standard, relate to materials, components or complete end-use products. Contains a new informative Annex with an example of the fire hazard assessment technique. The example is based on a hypothetical installation of rigid plastic conduit and quantifies the contribution of it to the total fire hazard in an actual fire scenario. Has the status of a basic safety publication in accordance with IEC Guide 104.
Prüfungen zur Beurteilung der Brandgefahr -- Teil 1-1: Anleitung zur Beurteilung der Brandgefahr von elektrotechnischen Erzeugnissen - Allgemeiner Leitfaden
Essais relatifs aux risques du feu -- Partie 1-1: Guide pour l'évaluation des risques du feu des produits électrotechniques - Directives générales
Fournit des directives pour évaluer les risques du feu des produits électrotechniques et pour développer en conséquence les essais relatifs aux risques de feu liés directement aux dommages aux personnes aux animaux ou aux biens. Les produits définis dans cette norme désignent les matériaux les composants ou les produits finis complets. Contient une nouvelle Annexe informative avec un exemple de technique d'estimation des risques du feu. L'exemple est basé sur une installation hypothétique d'un conduit rigide en matière plastique et il quantifie la contribution de ce produit par rapport aux risques totaux de feu dans un scénario feu réel. A le statut, d'une publication fondamentale de sécurité conformément au Guide 104.
Preskušanje požarne ogroženosti - 1-1. del: Navodila za ocenjevanje požarne ogroženosti pri elektrotehničnih proizvodih - Splošna navodila (IEC 60695-1-1:1999+corrigendum 2000)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 60695-1-1:2000
01-junij-2000
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SIST EN 60695-1-1:1999
3UHVNXãDQMHSRåDUQHRJURåHQRVWLGHO 1DYRGLOD]DRFHQMHYDQMHSRåDUQH
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Fire hazard testing -- Part 1-1: Guidance for assessing the fire hazard of electrotechnical
products - General guidelines
Prüfungen zur Beurteilung der Brandgefahr -- Teil 1-1: Anleitung zur Beurteilung der
Brandgefahr von elektrotechnischen Erzeugnissen - Allgemeiner Leitfaden
Essais relatifs aux risques du feu -- Partie 1-1: Guide pour l'évaluation des risques du feu
des produits électrotechniques - Directives générales
Ta slovenski standard je istoveten z: EN 60695-1-1:2000
ICS:
13.220.40 Sposobnost vžiga in Ignitability and burning
obnašanje materialov in behaviour of materials and
proizvodov pri gorenju products
29.020 Elektrotehnika na splošno Electrical engineering in
general
SIST EN 60695-1-1:2000 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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NORME CEI
INTERNATIONALE IEC
60695-1-1
INTERNATIONAL
Troisième édition
STANDARD
Third edition
1999-11
PUBLICATION FONDAMENTALE DE SÉCURITÉ
BASIC SAFETY PUBLICATION
Essais relatifs aux risques du feu –
Partie 1-1:
Guide pour l'évaluation des risques du feu
des produits électrotechniques –
Directives générales
Fire hazard testing –
Part 1-1:
Guidance for assessing the fire hazard of
electrotechnical products –
General guidelines
IEC 1999 Droits de reproduction réservés Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in
utilisée sous quelque forme que ce soit et par aucun procédé, any form or by any means, electronic or mechanical,
électronique ou mécanique, y compris la photo-copie et les including photocopying and microfilm, without permission in
microfilms, sans l'accord écrit de l'éditeur. writing from the publisher.
International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: +41 22 919 0300 e-mail: inmail@iec.ch IEC web site http://www.iec.ch
CODE PRIX
Commission Electrotechnique Internationale
W
PRICE CODE
International Electrotechnical Commission
Pour prix, voir catalogue en vigueur
For price, see current catalogue
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60695-1-1 © IEC:1999 – 3 –
CONTENTS
Page
FOREWORD.5
INTRODUCTION.9
Clause
1 Scope.11
2 Normative references.11
3 Definitions .11
4 Fire hazard assessment.13
4.1 General .13
4.2 Development of fire hazard assessment.13
5 Fire hazard tests. 21
5.1 General .21
5.2 Hazard assessment .21
5.3 Types of fire hazard tests.21
5.4 Preparation of requirements and test specifications.25
Annex A (informative) Flow charts .31
Annex B (informative) Use of rigid plastic conduit – A fire hazard assessment .47
Bibliography .73
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60695-1-1 © IEC:1999 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FIRE HAZARD TESTING –
Part 1-1: Guidance for assessing the fire hazard of
electrotechnical products – General guidelines
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International
Organization for Standardization (ISO) in accordance with conditions determined by agreement between the
two organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports or guides and they are accepted by the National
Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60695-1-1 has been prepared by IEC technical committee 89: Fire
hazard testing.
This third edition cancels and replaces the second edition published in 1995 and the
corrigendum (1996). It also constitutes a technical revision.
This standard has the status of a basic safety standard in accordance with IEC Guide 104.
The text of this standard is based on the second edition, the corrigendum and the following
documents:
FDIS Report on voting
89/374/FDIS 89/381/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 3.
Annexes A and B are for information only.
The contents of the corrigenda of January 2000 and August 2000 have been included in this copy.
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60695-1-1 © IEC:1999 – 7 –
The committee has decided that this publication remains valid until 2005.
At this date, in accordance with the committee’s decision, the publication will be
•
reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
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60695-1-1 © IEC:1999 – 9 –
INTRODUCTION
The risk of fire needs to be considered in any electrical circuit. With regard to this risk, the
objective of component circuit and equipment design and the choice of material is to reduce
the likelihood of fire even in the event of foreseeable abnormal use, malfunction or failure. The
primary aim is to prevent ignition due to the electrically energized part but, if ignition and fire
do occur, to control the fire preferably within the bounds of the enclosure of the
electrotechnical product. In cases where surfaces of the electrotechnical products are exposed
to an external fire, care will be taken to ensure that they do not contribute to the fire growth to
a greater extent than the building products or structures in the immediately surrounding areas.
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60695-1-1 © IEC:1999 – 11 –
FIRE HAZARD TESTING –
Part 1-1: Guidance for assessing the fire hazard of
electrotechnical products – General guidelines
1 Scope
This part of IEC 60695 provides guidance for assessing the fire hazard of electrotechnical
products (see clause 4) and for the resulting development of fire hazard testing (see clause 5)
as related directly to harm to people, animals or property. Products, as defined in this
standard, relate to materials, components or complete end-use products.
This standard is intended as guidance to IEC committees, and should be used with respect to
their individual applications. Attention is drawn to the principles in IEC Guide 104, and to the
role of committees with safety pilot functions and safety group functions.
One of the responsibilities of a technical committee is, wherever applicable, to make use of
basic safety publications in the preparation of its publications.
2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this part of IEC 60695. For dated references, subsequent amendments
to, or revisions of, any of these publications do not apply. However, parties to agreements
based on this part of IEC 60695 are encouraged to investigate the possibility of applying the
most recent editions of the normative documents indicated below. For undated references, the
latest edition of the normative document referred to applies. Members of IEC and ISO maintain
registers of currently valid International Standards.
IEC 60695-4:1993, Fire hazard testing – Part 4: Terminology concerning fire tests
IEC Guide 104:1997, The preparation of safety publications and the use of basic safety
publications and group safety publications
IEC Guide 109:1995, Environmental aspects – Inclusion in electrotechnical product standards
ISO/IEC Guide 52:1990, Glossary of fire terms and definitions
3 Definitions
For the purposes of this part of IEC 60695, the following definitions apply.
3.1
fire hazard
the potential for injury or loss of life and/or damage to property by a fire
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60695-1-1 © IEC:1999 – 13 –
3.2
fire risk
the probability of fire
NOTE The risk is described in terms of probability, combining:
a) the frequency of occurrence of an undesired event to be expected in a given technical operation or state, and,
b) the extent of damage to be expected on the occurrence of the event.
4 Fire hazard assessment
4.1 General
It is important to understand and maintain the differences between "fire hazard" and "fire risk".
The primary concern for hazard assessment is to minimize the risk of fires caused by
electrically induced ignition within electrotechnical products and, should one start, to limit fire
propagation. External events, such as the outbreak of a fire in the environment, shall also be
considered, but as a secondary matter and to a lesser extent; however, deliberate misuse of
an electrotechnical product shall, in general, be disregarded.
Consideration shall also be given to heat release and opacity, toxicity and corrosivity of the
smoke from a burning product, and any necessary ability to function under fire conditions.
These hazards are all related to ignition and fire growth. The emission of gases may also lead
to a risk of explosion under certain circumstances.
Certain electrotechnical products, such as large enclosures, insulated cables and conduits,
may in fact cover large portions of surfaces and finishing materials of building construction or
may penetrate fire-resisting walls. In these circumstances, electrotechnical products, when
exposed to an external fire, shall be evaluated from the standpoint of their contribution to the
fire hazard in comparison to the building materials or structure lacking the installation of
electrotechnical products.
Following a detailed review of all the hazards related to a fire scenario, the final product
standards, as drafted, should include a series of tests or a single test, as appropriate, to
address the specific hazard(s) defined.
4.2 Development of fire hazard assessment
4.2.1 Overview of fire hazard elements
The fire hazard of an electrotechnical product depends on its characteristics, service
conditions and the environment in which it is used, including the number and type of people,
the value and vulnerability of property to be exposed to a fire involving that product. Therefore,
a fire hazard assessment procedure for a particular product shall describe the product, its
conditions of operation and its environment.
4.2.2 Basic steps
The basic steps to follow in developing a fire hazard assessment are:
a) the definition of the scope (for example, the electrotechnical product range concerned) and
the context (for example, where and how the products are used) (see 4.2.2.1);
b) the identification of the scenarios of concern (see 4.2.2.2);
c) the selection of the criteria to be used (see 4.2.2.3);
d) the interpretation of results (see 4.2.2.4).
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60695-1-1 © IEC:1999 – 15 –
4.2.2.1 Definition of the scope and context
The first step involves defining the range of electrotechnical products to which the fire hazard
assessment is to apply, examining the points of variability and commonality in the product
range and its uses which may define the parameters of the fire hazard assessment procedure.
This may be done by answering the questions set out below.
Range of electrotechnical products
a)
What is the definition of the product to be covered? Is the product described well enough
that it can always be determined whether the product is in the range? Is it described by an
applicable IEC standard? Is the description broad enough so that all products capable of
substituting for the products covered are also included? Does the scope allow it to be
determined if a given product is covered?
b) Circumstances of use
What are the service conditions of the electrotechnical product: continuous or intermittent
use? Is the product attended or not during service? Is the surrounding temperature
controlled?
What does the location of the electrotechnical product indicate about its role in causing or
propagating fire, resulting from its interaction with other objects in the environment?
Is the product always in an enclosed or exposed space?
What are the number and capabilities of persons involved?
How close is the exposed population or critical equipment to the fire?
c) Testing of the defined scope and context
Using the answers to the above questions, formulate a trial description of the product and
its circumstances of use. The trial description can then be tested against a list of products,
which are potentially candidates for inclusion in the scope and context, by making use of
the procedure outlined in annex A, flow chart 1.
4.2.2.2 Identification of scenarios of concern
A fire scenario is a detailed description of conditions of one or more stages in an actual fire
from before ignition to completion of combustion, or a full-scale simulation. There will often be
more than one fire scenario in which the electrotechnical product can participate, and in
principle, the product can be assumed to contribute differently to the fire hazard associated
with each scenario. Therefore, a separate hazard assessment is required for each important
scenario identified.
Whether the focus of assessment is a product or a system, typically the most important
scenario characteristics will be those that either define the fire conditions that cause the
product to become involved in fire, or that indicate the time in the fire when its contribution will
cause the greatest hazard consequences.
a) Electrotechnical product involvement in fire
The knowledge of the source of ignition is of prime importance in the case of electrotechnical
products. If the product is its own source of ignition, conditions through which the ignition
could take place are to be analyzed in detail in terms of electrical behaviour (see table 1).
Is it a short circuit (which is seldom the case), a hot spot (cause of the hot spot), or a
general overheating? How long did the electrical malfunction continue before ignition took
place? Each scenario should give a precise description of the detailed conditions
governing the initiation of the fire, including the possible accumulation of gases within an
enclosed space.
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60695-1-1 © IEC:1999 – 17 –
If the electrotechnical product is not its own source of ignition, describe when and how it
tends to become involved in fire:
– Is the product likely to be the first item ignited?
– Is the product a potentially significant fuel source, even if it is not the first item ignited?
– Is the product a potential agent for fire propagation?
If one of these situations can be identified as being the greatest concern, then this may
mean that a single fire performance characteristic is of the greatest importance, such as
that product's ability to generate a significant hazard quickly, the quantity of products in
use, or the persistence of the hazard during and after suppression operations. Such
determinations can then be used to define test methods or calculation procedures that will
measure the product's contribution to fire hazard at these stages of a fire.
Relevant aspects of fire behaviour
b)
This exercise applies to both electrotechnical products and other objects in the
environment which may participate in the initiation, growth and development of fire.
The purpose of answering the questions posed is to characterize those hazard aspects
which are listed below (see also annex A, flow chart 2, charts 2A to 2F):
– potential to be an ignition source;
– ignitability;
– rate of flame spread;
– glowing, smouldering, melting;
– peak heat-release rate, fire growth rate, total heat release;
– mass loss or fire effluent generation rate;
– opacity of smoke produced;
– corrosivity of fire effluents produced;
– profile of toxic (irritant and asphyxiant) substances produced: rate, total toxic potency;
– maintenance of functions under fire conditions (for example structural integrity,
continuity of service, mechanical response);
– quantity of products in use relative to size and type of occupancy.
c) Use of scenarios to define key parameters
A test method or calculation procedure will require a number of specifications or input
values. For example, a test for rate of heat release of a burning product will require
specification of the type of ignition (for example, piloted ignition), the level of incident heat
flux, and any requirements for control of oxygen or humidity levels in the combustion
atmosphere. Where the product is not the first item ignited, nearby combustibles involved
will be important in determining the thermal conditions to which the product is exposed.
Each of the specifications and input values required by the test method or calculation
procedure should be determined from the characteristics of the scenario selected. This is
likely to require the use of statistics of relevant fires and some documented judgements by
experts. In completing these steps, the developer of a fire hazard assessment will need to
identify appropriate measurements and calculation procedures capable of characterizing
the hazard. A detailed examination of the scenario will provide the parameter specification
for these test methods and calculation procedures.
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60695-1-1 © IEC:1999 – 19 –
4.2.2.3 Selection of criteria to be used
The intent of this step is to select hazard measures that will provide valid technical information
sufficient to estimate and to make decisions on the product's contribution to fire hazard. Actual
damage to people and property is always the concern of the fire hazard assessment, but direct
measures of damage need not be used if it can be shown that simpler procedures will produce
the same results.
a) Direct life and property loss
If the contribution of the product to the hazard can be expressed in these terms, it is
desirable to do so. It is rare, however, that this can be accomplished, since rarely are the
capabilities of the occupants, or the equipment and property known with sufficient certainty
that the outcome to the scenario can be forecast quantitatively.
b) Indirect method of characterizing fire hazard
It is often possible to relate a measured or calculated product property to the build-up of
some aspect of fire hazard in the scenario. For example, the heat release rate of the
product may govern the temperature of the compartment and hence affect equipment
operation and/or continued human occupation. The rate of release of smoke from a
product may influence the escape time available to the occupants. In this approach, the
quantitative relationship between the hazard and the product's properties is identified, so
that changes in the level of hazard can be traced to changes in properties.
Comparative methods
c)
Even when it is not possible to express these relationships quantitatively it may be possible
to relate the performance of a tested product to a reference level. For example, cables with
a known heat release may be considered as providing an acceptably slow build-up of
temperature, even though the precise relationship is unknown. Then one measure of the
relative hazard is the comparison of the product's heat release rate with the reference
level.
4.2.2.4 Interpretation of results
At this point, the fire hazard assessment procedure will have identified which hazard measures
are to be used and how they are to be calculated, but the interpretation of the results may still
pose additional technical questions.
a) In assessing the hazard one should specify the procedure to be used in calculating an
overall fire hazard comparison between products, or when compared to a baseline. This
procedure might be a formula for calculating one overall hazard measure from several, in
which case, a scientific rationale will be presented for the formula. The procedure could be
a set of decision rules, such as a rule that one product is better than another only if it is
better in all hazard measures. However, in the specific case of two products, this rule may
not be sufficient to provide a definite comparison as to the overall hazard.
b) If more than one scenario has been used, it is necessary to specify the procedure to be
used in calculating an overall fire hazard. This procedure could be a formula or a set of
rules, for example if the scenario can be assigned relative probabilities of occurrence, as in
a fire risk assessment, this would be a basis for calculating the overall fire hazard from
several scenarios.
c) If the hazard is not expressed directly in terms of death, injuries or monetary loss, guidance
on the other quantitative units and measurements should be provided (i.e. escape time,
extent of flame spread, size of fire etc.).
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60695-1-1 © IEC:1999 – 21 –
d) The assessment should specify all the steps required to set a meaningful safety threshold,
or pass/fail criteria can be set by those responsible.
e) The points above relate to overall fire hazard assessment and the part played by
electrotechnical products within this assessment.
5 Fire hazard tests
5.1 General
The transmission, distribution, storage and utilization of energy of any type has the potential to
contribute to fire in most buildings.
The most frequent causes of ignition are overheating and arcing. The frequency of ignition will
depend on the type of materials used in the construction of the system.
Equipment in the electrotechnical field, when operating, involves heat dissipation and in some
cases arcing and sparking. These potential risks do not lead to hazardous conditions when
they are taken into account initially at the design stage, and afterwards during installation, use
and maintenance.
Hazardous conditions which do not arise from the use of electrotechnical equipment can and
do involve it. Considerations of this nature are dealt with in the overall hazard assessment.
Contrary to the commonly held belief that most electrical fires are caused by a short circuit,
electrical fires may be initiated from one or a combination of circumstances, including external
non-electrical sources (see also table 1).
These circumstances can include improper installation, utilization or maintenance conditions (for
example, operation under overload for temporary or extended periods, operation under
conditions not provided for by the manufacturer or contractor, inadequate heat dissipation,
clogged ventilation systems, etc.).
5.2 Hazard assessment
Data available for use in fire hazard assessment may be of any of these types:
a) test response results, based on application of small-scale test methods or large-scale test
protocols;
b) measurement of, or statistics on, characteristics of historical fires;
c) documented judgement by experts.
These data may be used directly as hazard measures or may be used as input data to a
calculation procedure that produces the final hazard evaluation.
5.3 Types of fire hazard tests
When possible, end-product tests are generally the most reliable test methods as they
normally duplicate exactly the conditions occurring in practice. When preparing requirements
and test specifications concerning fire and electrotechnical products the types of tests given
below should be recognized.
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60695-1-1 © IEC:1999 – 23 –
5.3.1 Fire simulation tests
These tests examine the reaction to fire of electrotechnical products and are aimed to be as
representative as possible of the use of the product in practice. Since the real conditions of
use (including foreseeable abnormal use, malfunction, or failure) of a product are simulated as
closely as possible, and the design of the test procedure is related to actual risks, such
tests assess the relevant aspects of the fire hazard associated with the use of the product.
The findings of such tests may not be valid when a change in the design is made, or when the
conditions of use are different from those simulated in the test.
5.3.2 Fire resistance tests
These tests are intended to assess the ability of a product or a part to preserve the various
properties for its use under specified conditions of exposure to fire, for a stated period of time.
They are intended to provide data on the behaviour and performance of a product or a finished
assembly under a particular condition of heat exposure.
Recent studies have shown that to relate the findings of such tests to performance in actual
fire situations, very careful consideration needs to be given to a comparison of the test
conditions with actual fire situations and the possible effect of any uncontrolled variables, such
as the environment in which the product is placed.
5.3.3 Tests of fire reaction
These tests examine the reaction to fire of standardized specimens under defined conditions
and in most cases are used to give data on properties related to burning behaviour and for a
comparative evaluation, such as flammability, ignitability, flame spread rate, smoke density,
fire effluents, heat release rate.
The data provided by such combustion characteristic tests are usually not representative of
other conditions to which the specimen may be subjected. Combustion characteristic tests can
be quite useful when designed to simulate as closely as possible the situation which materials
and components will meet when testing the complete product. However, the reaction to fire of
specimens can be very different from the reaction to fire of end products, because of
environmental differences.
5.3.4 Basic property tests
These tests are designed to ensure that, on measuring a basic physical or chemical property
of a material, they yield information that can be, at least approximately, technically defined
independent of the testing method. This is the case of net calorific value (or heat of
combustion), thermal conductivity, melting point, heat of vaporization and also, more or less,
of flash point, fire point and spontaneous ignition temperature.
In a real fire situation, a number of such properties, in accordance with the heat and mass
transfer theory, can collectively define behaviour; consequently, a single property
measurement will only define one aspect of the fire risk, or hazard associated with a system.
However, eventually, when fire engineering has a firmer technical base, results of such tests
may be used to assess a wide range of fire safety situations.
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5.4 Preparation of requirements and test specifications
When preparing requirements and test specifications concerning fire haz
...
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