IEC 60695-1-10:2009

Fire hazard testing - Part 1-10: Guidance for assessing the fire hazard of electrotechnical products - General guidelines

IEC 60695-1-10:2009 provides general guidance on how to reduce to acceptable levels the risk of fire and the potential effects of fires involving electrotechnical products. It also describes the relationship between fire risk and the potential effects of fire, it also emphasises the importance of the scenario approach to fire hazard and risk assessment and discusses criteria intended to ensure the development of technically sound hazard-based fire test methods. It has the status of a horizontal standard in accordance with IEC Guide 104 and ISO/IEC Guide 51.
This publication is to be read in conjunction with  IEC 60695-1-11:2010.

Essais relatif aux risques du feu - Partie 1-10: Lignes directrices pour l'évaluation des risques du feu des produits électrotechniques - Lignes directrices générales

La CEI 60695-1-10:2009 fournit des lignes directrices générales sur la manière de réduire à des niveaux acceptables le risque d'incendie et les effets potentiels des incendies impliquant des produits électrotechniques. Elle décrit la relation entre le risque d'incendie et les effets potentiels des incendies. Elle souligne l'importance de l'approche par scénario pour l'évaluation des dangers du feu et des risques d'incendie. Elle débat également des critères visant à assurer le développement de méthodes d'essai au feu basées sur les dangers qui soient techniquement solides. La présente publication fondamentale de sécurité est destinée aux comités d'études dans le cadre de l'élaboration de normes conformes aux principes exposés dans le Guide CEI 104 et le Guide ISO/CEI 51.
Cette publication doit être lue conjointement avec la CEI 60695-1-11:2010.

General Information

• Status: Published
• Publication Date: 24-Nov-2009
• ICS: 13.220.40 - Ignitability and burning behaviour of materials and products
• ICS: 29.020 - Electrical engineering in general
• Technical Committee: TC 89 - Fire hazard testing
• Drafting Committee: WG 10 - TC 89/WG 10
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 18-Nov-2016

Relations

• Revised: IEC 60695-1-10:2016 - Fire hazard testing - Part 1-10: Guidance for assessing the fire hazard of electrotechnical products - General guidelines
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60695-1-10
®
Edition 1.0 2009-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ
Fire hazard testing –
Part 1-10: Guidance for assessing the fire hazard of electrotechnical products –
General guidelines

Essais relatifs aux risques du feu –
Partie 1-10: Lignes directrices pour l'évaluation des risques du feu des produits
électrotechniques – Lignes directrices générales

IEC 60695-1-10:2009

---------------------- Page: 1 ----------------------
THIS PUBLICATION IS COPYRIGHT PROTECTED
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All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by
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IEC 60695-1-10
®
Edition 1.0 2009-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ
Fire hazard testing –
Part 1-10: Guidance for assessing the fire hazard of electrotechnical products –
General guidelines

Essais relatifs aux risques du feu –
Partie 1-10: Lignes directrices pour l'évaluation des risques du feu des produits
électrotechniques – Lignes directrices générales

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
Q
CODE PRIX
ICS 13.220.40, 29.020 ISBN 978-2-88910-252-5
® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

---------------------- Page: 3 ----------------------
– 2 – 60695-1-10 © IEC:2009
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

FIRE HAZARD TESTING –

Part 1-10: Guidance for assessing
the fire hazard of electrotechnical products –
General guidelines


FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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agreement between the two organizations.
2) The formal decisions or agreements of 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
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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6) All users should ensure that they have the latest edition of this publication.
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60695-1-10 has been prepared by IEC technical committee 89:
Fire hazard testing.
1
, cancels and replaces the
This first edition of this standard, together with IEC 60695-1-11
third edition of IEC 60695-1-1, published in 1999 and constitutes a technical revision.
It has the status of a basic safety publication in accordance with IEC Guide 104 and ISO/IEC
Guide 51.
This standard is to be used in conjunction with IEC 60695-1-11.
___________
1
 To be published.

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60695-1-10 © IEC:2009 – 3 –
The text of this standard is based on the following documents:
FDIS Report on voting
89/950/FDIS 89/963/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 2.
A list of all the parts in the IEC 60695 series, under the general title Fire hazard testing, can
be found on the IEC website.
Part 1 consists of the following parts:
Part 1-10: Guidance for assessing the fire hazard of electrotechnical products – General
guidelines
Part 1-11: Guidance for assessing the fire hazard of electrotechnical products – Fire hazard
assessment
Part 1-20: Guidance for assessing the fire hazard of electrotechnical products – Ignitability –
General guidance
Part 1-21: Guidance for assessing the fire hazard of electrotechnical products – Ignitability –
Summary and relevance of test methods
Part 1-30: Guidance for assessing the fire hazard of electrotechnical products – Preselection
testing process – General guidelines
Part 1-40: Guidance for assessing the fire hazard of electrotechnical products – Insulating
liquids
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

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– 4 – 60695-1-10 © IEC:2009
INTRODUCTION
In the design of any electrotechnical product the risk of fire and the potential hazards
associated with fire need to be considered. In this respect the objective of component, circuit
and product design as well as the choice of materials is to reduce to acceptable levels the
potential risks of fire even in the event of foreseeable abnormal use, malfunction or failure.
This standard, together with its companion, IEC 60695-1-11, provides guidance on how this is
to be accomplished.
The primary aims are to prevent ignition caused by an electrically energised component part
and, in the event of ignition, to confine any resulting fire within the bounds of the enclosure of
the electrotechnical product.
Secondary aims include the minimisation of any flame spread beyond the product’s enclosure
and the minimisation of harmful effects of fire effluents including heat, smoke, and toxic or
corrosive combustion products.
Fires involving electrotechnical products can also be initiated from external non-electrical
sources. Considerations of this nature are dealt with in the overall risk assessment.
Assessing the fire hazard of electrotechnical products is accomplished by performing fire
hazard tests. These tests are divided into two fundamental groups: qualitative fire tests and
quantitative fire tests.
Fire testing of electrotechnical products should, whenever possible, be carried out using
quantitative fire tests having the following characteristics:
a) The test should take into account the circumstances of product use, i.e. contemplated
end-use conditions as well as foreseeable abnormal use. This is because fire conditions
that may be hazardous under one set of circumstances will not necessarily pose the same
threat under a different set.
b) It should be possible to correlate the test results with the harmful effects of fire effluents
referred to above, i.e. the thermal and airborne threats to people and/or property in the
relevant end-use situation. This avoids the creation of artificial, and sometimes distorted,
performance scales with no clear relationship to fire safety.
c) Recognizing that there are usually multiple contributions to the effects of real fires, the
test results should be expressed in well defined terms and using rational scientific units,
so that the product's contribution to the overall fire effects can be quantitatively assessed
and compared with that of other products’ contributions.
Although quantitative tests are preferred, the characteristics of qualitative fire tests are that
they provide pass/fail and classification results. Under certain circumstances it will be
appropriate to maintain such qualitative test methods or to develop new ones. This part of
IEC 60695-1 establishes the circumstances under which such maintenance or development is
appropriate.

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60695-1-10 © IEC:2009 – 5 –
FIRE HAZARD TESTING –

Part 1-10: Guidance for assessing
the fire hazard of electrotechnical products –
General guidelines



1 Scope
This part of IEC 60695-1 provides general guidance on how to reduce to acceptable levels the
risk of fire and the potential effects of fires involving electrotechnical products. It also serves
as a signpost standard to the other guidance publications in the IEC 60695 series.
It describes the relationship between fire risk and the potential effects of fire, and provides
guidance to IEC product committees on the applicability of qualitative and quantitative fire
tests to the fire hazard assessment of electrotechnical products.
It emphasises the importance of the scenario approach to fire hazard and risk assessment
and discusses criteria intended to ensure the development of technically sound hazard-based
fire test methods.
It discusses the different types of fire tests, in particular, the nature of qualitative and
quantitative fire tests. It also describes the circumstances under which it is appropriate for
IEC product committees to maintain or develop qualitative fire tests.
This standard is intended as guidance to IEC committees, and should be used with respect to
their individual applications.
This basic safety publication is intended for use by technical committees in the preparation of
standards in accordance with the principles laid down in IEC Guide 104 and ISO/IEC
Guide 51.
One of the responsibilities of a technical committee is, wherever applicable, to make use of
basic safety publications in the preparation of its publications. The requirements, test
methods or test conditions of this basic safety publication will not apply unless specifically
referred to or included in the relevant publications.
2 Normative references
The following referenced documents are indispensable for the application 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.
IEC 60695 (all parts), Fire hazard testing
IEC 60695-1-11: Fire hazard testing – Part 1-11: Guidance for assessing the fire hazard of
2
electrotechnical products – Fire hazard assessment
IEC 60695-1-30:2008, Fire hazard testing – Part 1-30: Guidance for assessing the fire hazard
of electrotechnical products – Preselection testing process – General guidelines
___________
2
To be published.

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– 6 – 60695-1-10 © IEC:2009
IEC/TS 62441:2006, Accidentally caused candle flame ignition for audio/video,
communication and information technology equipment
IEC Guide 104:1997, The preparation of safety publications and the use of basic safety
publications and group safety publications
ISO/IEC Guide 51:1999, Safety aspects – Guidelines for their inclusion in standards
3
ISO 19706 :2007, Guidelines for assessing the fire threat to people
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
fire
〈uncontrolled〉 self-supporting combustion that has not been deliberately arranged to provide
useful effects and is not limited in its extent in time and space
[ISO/IEC 13943, definition 4.98]
3.2
fire hazard
physical object or condition with a potential for an undesirable consequence from fire
[ISO/IEC 13943, definition 4.112]
3.3
fire risk
probability of a fire combined with a quantified measure of its consequence
NOTE It is often calculated as the product of probability and consequence.
[ISO/IEC 13943, definition 4.124]
3.4
fire-safety engineering
application of engineering methods based on scientific principles to the development or
assessment of designs in the built environment through the analysis of specific fire scenarios
or through the quantification of risk for a group of fire scenarios
[ISO/IEC 13943, definition 4.126]
3.5
fire scenario
qualitative description of the course of a fire with respect to time, identifying key events that
characterise the studied fire and differentiate it from other possible fires
NOTE It typically defines the ignition and fire growth processes, the fully developed fire stage, the fire decay
stage, and the environment and systems that impact on the course of the fire.
[ISO/IEC 13943, definition 4.129]
3.6
intermediate-scale fire test
fire test performed on a test specimen of medium dimensions
___________
3
 ISO 9122-1, Toxicity testing of fire effluents – Part 1: General, has been withdrawn and replaced by
ISO 19706.

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60695-1-10 © IEC:2009 – 7 –
NOTE A fire test performed on a test specimen for which the maximum dimension is between 1 m and 3 m is
usually called an intermediate-scale fire test.
[ISO/IEC 13943, definition 4.200]
3.7
large-scale fire test
fire test that cannot be carried out in a typical laboratory chamber, performed on a test
specimen of large dimensions
NOTE A fire test performed on a test specimen of which the maximum dimension is greater than 3 m is usually
called a large-scale fire test.
[ISO/IEC 13943, definition 4.205]
3.8
qualitative fire test
fire test which is either:
a) a pass/fail test; or
b) a test which categorizes the behaviour of the test specimen by determining its position
in a rank order of performance
3.9
quantitative fire test
fire test which takes into account the circumstances of product use in which the test
conditions are based on, or are relatable to, the circumstances of use of the test specimen,
and which measures a parameter or parameters, expressed in well defined terms and using
rational scientific units, which can be used in the quantitative assessment of fire risk
3.10
reaction to fire
response of a test specimen when it is exposed to fire under specified conditions in a fire test
NOTE Fire resistance is regarded as a special case and is not normally considered as a ‘reaction to fire’ property.
[ISO/IEC 13943, definition 4.272]
3.11
real-scale fire test
fire test that simulates a given application, taking into account the real scale, the real way the
item is installed and used, and the environment
NOTE Such a fire test normally assumes that the products are used in accordance with the conditions laid down
by the specifier and/or in accordance with normal practice.
[ISO/IEC 13943, definition 4.273]
3.12
small-scale fire test
fire test performed on a test specimen of small dimensions
NOTE A fire test performed on a test specimen of which the maximum dimension is less than 1 m is usually called
a small-scale fire test.
[ISO/IEC 13943, definition 4.292]
4 Fire hazards associated with electrotechnical products
The transmission, distribution, storage and utilization of electrical energy can have the
potential to contribute to fire hazard.

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– 8 – 60695-1-10 © IEC:2009
With electrotechnical products the most frequent causes of ignition are overheating and
arcing. The likelihood of ignition will depend on the product and system design, the use of
safety devices and systems, and type of materials used.
Electrotechnical products, when operating, generate heat and in some cases arcing and
sparking are normal phenomena. These potential risks should not lead to hazardous
conditions provided that they have been taken into account initially at the design stage, and
subsequently during installation, use and maintenance.
Although it is a commonly held belief that most electrical fires are caused by a short-circuit,
there are many other possible causes of ignition. These can include improper installation,
improper utilization and inadequate maintenance. Examples are: operation under overload for
temporary or extended periods; operation under conditions not provided for by the
manufacturer or contractor; inadequate heat dissipation; and faulty ventilation. Table 1 lists
common ignition phenomena encountered in electrotechnical products.
Unless otherwise indicated, the sources of ignition are considered to be internal to the
electrotechnical product. It includes the most frequently encountered cases. The sequence
indicated is not related to the magnitude or frequency of occurrence.
Fires involving electrotechnical products can also be initiated from external non-electrical
sources. Hazardous conditions, which do not arise from the use of the electrotechnical
product itself, can and often do involve that product. Considerations of this nature are dealt
with in the overall hazard assessment, individual product safety standards, or for example by
the provisions of IEC/TS 62441.
When designing products, the prevention of ignition in normal and abnormal operating
conditions requires a higher priority compared to minimizing eventual spread of flames.
After ignition has occurred, for whatever reason, the effects of the subsequent fire must be
assessed. Factors to be taken into account include:
a) fire growth and flame spread;
b) heat release;
c) smoke generation (visibility);
d) production of toxic fire effluent;
e) production of potentially corrosive fire effluent;
f) the potential of explosion.
References to TC 89 guidance on items a) through f) can be found in Clause 9.
5 Fundamentals of fire hazard testing
5.1 Objectives
The objectives of fire hazard testing of electrotechnical products are to determine which fire
properties of the product contribute to the potential effects of fire and/or how the product or
part of the product contributes to the initiation, growth and effect of fire, and then to use this
knowledge to reduce the risks of fire in electrotechnical products.
5.2 Fire hazard and fire risk
5.2.1 Fire hazard
A fire hazard is a physical object or condition with a potential for an undesirable consequence
from fire (see 3.2). Fire hazards therefore encompass potential fuels and ignition sources.
Ignition of an electrotechnical product can be caused by an electrically energised component

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60695-1-10 © IEC:2009 – 9 –
part, and the conditions which can cause ignition are of three types: an abnormal temperature
rise, a short-circuit, or accidental arcs or sparks. Table 1 lists possible origins of such
phenomena and also lists the possible consequential effects.
Fires involving electrotechnical products can also be initiated from external non-electrical
sources, and an overall risk assessment should include this possibility.

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– 10 –               60695-1-10 © IEC:2009

Table 1 – Common ignition phenomena encountered in electrotechnical products
a b
Phenomenon Origin Consequential effects
b
Abnormal temperature rises Overcurrent in a conductor At start, protection devices are not activated (except in
special protection cases). They may be activated after a
Defective contacts
NOTE 1 Some products dissipate heat
variable length of time
in normal operation.
Leakage currents (insulation loss and heating)
The temperature rises are gradual and at times very slow.
Therefore a significant accumulation of heat and effluent in
Failure of a component, an internal part or an associated
the vicinity of the product may result, sufficient to support fire
system (for example, ventilation)
as soon as ignition starts
Mechanical distortions which modify electrical contacts or
Accumulation and diffusion of flammable gases in air may
the insulation system
give rise to an ignition or explosion, especially inside
Seizure of a motor shaft (locked rotor)
hermetically sealed products
Premature thermal ageing A locked motor shaft (locked rotor) can cause smouldering or
flaming due to excessive heating of the windings of the motor
b
Short-circuit Direct contact of conducting live parts at different The protection devices are activated
potentials (loosening of terminals, disengaged
The rise in temperature is significant after a very short time
conductors, ingress of conducting foreign bodies, etc.)
and is quite localized
Gradual degradation of some components causing
Possible emission of light, smoke, flammable gases
changes in their insulation impedances
Release of glowing materials or substances
After sudden failure of component or internal part
b
Accidental sparks and arcs Cause external to the product (overvoltage of the system The protection devices may not always be activated
network, accidental mechanical action exposing live parts
Possible emission of visible light, flammable gases and
NOTE 2 Some products produce arcs
or bringing them together, etc.)
flames Substantial risk of ignition in potentially explosive
and sparks in normal operation.
Internal cause (on-off switching with gradual degradation atmospheres
of some components and ingress of moisture)
Ignition may occur locally in surrounding components or
After sudden failure of a component or an internal part gases
b
High transient peak current Defect in the electrical circuit The protection devices may not always be activated
a
Mechanical distortions and structural changes induced by any one of the three phenomena may result in the occurrence of the other two.
b
The protection devices may include thermal, mechanical, electrical or electronic types.

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60695-1-10 © IEC:2009 – 11 –
5.2.2 Fire risk
In order to calculate fire risk, it is necessary to quantify the consequences of the fire that is
being assessed. The consequences may refer to injury or loss of life from threats such as
heat, low oxygen levels, or the concentration of incapacitating fire gases; or the
consequences may refer to loss of property, such as the extent of fire damage. A wide range
of potential fire scenarios may be analysed quantitatively to establish measures of overall fire
risk.
If c is the consequence of the fire (i.e. a quantified measure), and p is the probability of the
fire occurring within a defined time period, then the fire risk (in that time period) is usually
calculated as the product of p and c
Fire risk = p × c
If it is assumed that, within a given time-frame, that there is a probability, p , of a fire incident
1
involving a given product in a given scenario (scenario 1), and a probability, p , of a fire
2
incident involving the same product in a different scenario (scenario 2), and so on, covering
all relevant scenarios, the total fire risk associated with that product, within that time-frame is:
m
Total fire risk = p c
∑ i i
i=1
where
p is the probability of scenario i;
i
c is the consequence of scenario i;
i
m is the total number of scenarios being considered.
NOTE Further discussions of fire risk, and its use in selecting scenarios on which to base fire hazard tests, can
4
be found in ISO/TS 16732 [2] .
5.3 Fire scenarios
Fire scenarios differ in fire stages (phases), the oxygen content, the CO /CO ratio, the
2
temperature and the irradiance (see Table 1 in ISO 19706).
Analysis of the circumstances of use of a product involved in a given fire incident (real or
hypothetical) facilitates the description of the conditions and the chain of events that play a
significant role in the outcome of the fire.
There is a scenario associated with every fire incident involving a given product. While in
principle e
...