IEC 60695-1-11:2010

IEC 60695-1-11
®
Edition 1.0 2010-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ
Fire hazard testing –
Part 1-11: Guidance for assessing the fire hazard of electrotechnical products –
Fire hazard assessment

Essais relatifs aux risques du feu –
Partie 1-11: Lignes directrices pour l’évaluation des risques du feu des produits
électrotechniques – Evaluation des risques du feu

IEC 60695-1-11:2010

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IEC 60695-1-11
®
Edition 1.0 2010-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ
Fire hazard testing –
Part 1-11: Guidance for assessing the fire hazard of electrotechnical products –
Fire hazard assessment

Essais relatifs aux risques du feu –
Partie 1-11: Lignes directrices pour l’évaluation des risques du feu des produits
électrotechniques – Evaluation des risques du feu

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
X
CODE PRIX
ICS 13.220.40; 29.020 ISBN 978-2-88912-027-7
® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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– 2 – 60695-1-11 © IEC:2010
CONTENTS
FOREWORD.4
INTRODUCTION.6
1 Scope.7
2 Normative references .7
3 Terms and definitions .8
4 Elements of fire hazard assessment .14
4.1 Ignition sources.14
4.2 Fire hazard.14
4.3 Fire risk.14
4.4 Fire hazard assessment .14
5 Fire hazard tests .15
6 The fire hazard assessment process .15
6.1 General .15
6.2 Definition of the product range and the circumstances of use .16
6.3 Identification and analysis of fire scenarios .16
6.3.1 General .16
6.3.2 Qualitative description of the fire scenario .17
6.3.3 Quantitative analysis of the fire scenario .18
6.3.4 Simple hypothetical fire scenarios .19
6.4 Selection of criteria for acceptable fire scenario outcomes .19
6.5 Performance requirements .20
6.6 Interpretation of test results.20
6.7 Consequential testing.20
7 Scope and limitations of the fire hazard assessment .20
8 Fire test requirements and specifications.21
Annex A (informative) Calculation of acceptable toxic yield values for an electrical
insulation material, based on a simple hypothetical fire scenario .26
Annex B (informative) Use of rigid plastic conduit – A fire hazard assessment .31
Bibliography.43

Figure B.1 – Schematic of conduit installation.38
Figure B.2 – Corridor upper layer temperature (concrete wall) .38
Figure B.3 – Corridor upper layer temperature (gypsum wall board).39
Figure B.4 – Flux measured at the conduit 2 m away (concrete wall) .39
Figure B.5 – Flux measured at the conduit 2 m away (gypsum wall).40
Figure B.6 – Comparative mass loss rates of furniture and conduit (concrete wall) .40
Figure B.7 – Comparative mass loss rates of furniture and conduit (gypsum wall board).41
Figure B.8 – Relative increase of toxicity due to exposed conduit (concrete wall) .41
Figure B.9 – Relative increase of toxicity due to exposed conduit (gypsum wall board) .42

Table A.1 – Irritant F values and calculated X values for the defined fire scenario .27
Table A.2 – Asphyxiant X values calculated for the defined fire scenario.28
Table A.3 – Incapacitation times for hydrogen cyanide.29

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60695-1-11 © IEC:2010 – 3 –
Table A.4 – Multiplication factors for carbon dioxide .30
Table B.1 – Summary of fire scenario information .33
Table B.2 – Time of occurrence of highly-hazardous conditions in building corridors.36

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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

FIRE HAZARD TESTING –

Part 1-11: Guidance for assessing
the fire hazard of electrotechnical products –
Fire hazard assessment


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
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). 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. 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 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 IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
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 60695-1-11 has been prepared by IEC technical committee 89:
Fire hazard testing.
This first edition of this standard, together with IEC 60695-1-10, cancels and replaces the
third edition of IEC 60695-1-1 published in 1999, and corrigenda 1 and 2 (2000). It also
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 60695-1-10

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60695-1-11 © IEC:2010 – 5 –
The text of this standard is based on the following documents:
FDIS Report on voting
89/991A/FDIS 89/1005/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 stability 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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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 equipment 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 60695-1-10, 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 fire hazard assessment.
Fire hazard assessment is used to identify the kinds of fire events (fire scenarios) which will
be associated with the product, to establish how the measurable fire properties of the product
are related to the outcome of those events, and to establish test methods and performance
requirements for those properties which will either result in a tolerable fire outcome or
eliminate the event altogether.
Annex A demonstrates a relatively simple fire hazard assessment process as applied to the
toxic hazard from a burning material.
Annex B demonstrates a more complex fire hazard assessment process as applied to an
electrotechnical product: rigid plastic conduit.
Attention is drawn to the principles in IEC Guide 104, and to the role of committees with
horizontal safety functions and group safety functions.

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60695-1-11 © IEC:2010 – 7 –
FIRE HAZARD TESTING –

Part 1-11: Guidance for assessing
the fire hazard of electrotechnical products –
Fire hazard assessment



1 Scope
This part of IEC 60695-1 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. For the purposes of this standard, product means complete
electrotechnical equipments, their parts (including components) and electrical insulating
materials.
It outlines a hazard-based process to identify appropriate fire test methods and performance
criteria for products. The principles of the methodology are to identify fire events (fire
scenarios) which will be associated with the product, to establish how the measurable fire
properties of the product are related to the possible occurrence and outcome of those events,
and to establish test methods and performance requirements for those properties which will
either result in a tolerable fire outcome or eliminate the event altogether.
This standard is intended as guidance to IEC committees, and should be used with respect to
their individual applications. The actual implementation of this standard remains the
responsibility of each product committee, according to the minimum acceptable fire safety in
its application field and taking into account the feedback from experience.
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 60695-1-10:2009, Fire hazard testing – Part 1-10: Guidance for assessing the fire hazard
of electrotechnical products – General guidelines
IEC 60695-1-21:2008, Fire hazard testing – Part 1-21: Guidance for assessing the fire hazard
of electrotechnical products – Ignitability – Summary and relevance of test methods
IEC/TS 60695-5-2:2002, Fire hazard testing – Part 5-2: Corrosion damage effects of fire
effluents – Summary and relevance of test methods
IEC/TS 60695-6-2:2005, Fire hazard testing – Part 6-2: Smoke obscuration – Summary and
relevance of test methods

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– 8 – 60695-1-11 © IEC:2010
IEC/TR 60695-7-2:2002, Fire hazard testing – Part 7-2: Toxicity of fire effluent – Summary
and relevance of test methods
IEC/TR 60695-8-2:2008, Fire hazard testing – Part 8-2: Heat release – Summary and
relevance of test methods
IEC/TS 60695-9-2:2005, Fire hazard testing – Part 9-2: Surface spread of flame – Summary
and relevance of test methods
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
ISO/IEC 13943:2008, Fire safety – Vocabulary
ISO/TR 13387:1999 (all parts), Fire safety engineering
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC 13943, some of
which are reproduced below for the use’ convenience, as well as the followings apply.
3.1
asphyxiant
toxicant that causes hypoxia, which can result in central nervous system depression or
cardiovascular effects
NOTE Loss of consciousness and ultimately death may occur.
[ISO/IEC 13943, definition 4.17]
3.2
available safe escape time
ASET
time available for escape for an individual occupant, the calculated time interval between the
time of ignition (3.27) and the time at which conditions become such that the occupant is
estimated to be incapacitated, i.e. unable to take effective action to escape (3.8) to a safe
refuge or place of safety
NOTE 1 The time of ignition can be known, e.g. in the case of a fire model or a fire test, or it may be assumed,
e.g. it may be based upon an estimate working back from the time of detection. The basis on which the time of
ignition is determined is always stated.
NOTE 2 This definition equates incapacitation with failure to escape. Other criteria for ASET are possible. If an
alternate criterion is selected, it is necessary that it be stated.
NOTE 3 Each occupant can have a different value of ASET, depending on that occupant’s personal
characteristics.
[ISO/IEC 13943, definition 4.20]
3.3
built environment
building or other structure
EXAMPLES Off-shore platforms, civil engineering works such as tunnels, bridges and mines; and means of
transportation such as motor vehicles and marine vessels.
NOTE ISO 6707-1 contains a number of terms and definitions for concepts related to the built environment.
[ISO/IEC 13943, definition 4.26]

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60695-1-11 © IEC:2010 – 9 –
3.4
combustion
exothermic reaction of a substance with an oxidizing agent
NOTE Combustion generally emits fire effluent accompanied by flames and/or glowing.
[ISO/IEC 13943, definition 4.46]
3.5
combustion product
product of combustion
solid, liquid and gaseous material resulting from combustion (3.4)
NOTE Combustion products can include fire effluent, ash, char, clinker and/or soot.
[ISO/IEC 13943, definition 4.48]
3.6
effective heat of combustion
heat released (3.25) from a burning test specimen in a given time interval divided by the mass
lost from the test specimen in the same time period
NOTE 1 It is the same as the net heat of combustion if all the test specimen is converted to volatile combustion
(3.4) products and if all the combustion products (3.5) are fully oxidized.
-1
NOTE 2 The typical units are kJ⋅g .
[ISO/IEC 13943, definition 4.74]
3.7
environment
conditions and surroundings that may influence the behaviour of an item or persons when
exposed to fire (3.13)
[ISO/IEC 13943, definition 4.80]
3.8
escape
effective action taken to reach a safe refuge or place of safety
[ISO/IEC 13943, definition 4.82]
3.9
exposure dose
measure of the maximum amount of a toxic gas or fire effluent (3.14) which is available for
inhalation, calculated by integration of the area under a concentration-time curve
–3
NOTE 1 For fire effluent, typical units are grams times minutes per cubic metre (g·min·m ).
–1
NOTE 2 For a toxic gas, typical units are microlitres times minutes per litre (μL·min·L ) (at T = 298 K and
P = 1 atm).
[ISO/IEC 13943, definition 4.89]
3.10
extinction area of smoke
product of the volume occupied by smoke (3.35) and the extinction coefficient of the smoke
2
NOTE It is a measure of the amount of smoke, and the typical units are square metres (m ).
[ISO/IEC 13943, definition 4.92]

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3.11
fire
(general) process of combustion (3.4) characterized by the emission of heat and fire effluent
(3.14) and usually accompanied by smoke (3.35), flame or glowing or a combination thereof
NOTE In the English language, the term "fire" is used to designate three concepts, two of which, fire (3.12) and
fire (3.13), relate to specific types of self-supporting combustion with different meanings and two of them are
designated using two different terms in both French and German.
[ISO/IEC 13943, definition 4.96]
3.12
fire
(controlled) self-supporting combustion (3.4) that has been deliberately arranged to provide
useful effects and is limited in its extent in time and space
[ISO/IEC 13943, definition 4.97]
3.13
fire
(uncontrolled) self-supporting combustion (3.4) 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]
3.14
fire effluent
totality of gases and aerosols, including suspended particles, created by combustion (3.4) or
pyrolysis in a fire (3.11)
[ISO/IEC 13943, definition 4.105]
3.15
fire growth
stage of fire (3.11) development during which the heat release rate (3.26) and the
temperature of the fire are increasing
[ISO/IEC 13943, definition 4.111]
3.16
fire hazard
physical object or condition with a potential for an undesirable consequence from fire (3.13)
[ISO/IEC 13943, definition 4.112]
3.17
fire risk
probability of a fire (3.13) 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]
3.18
fire safety engineering
application of engineering methods based on scientific principles to the development or
assessment of designs in the built environment (3.3) through the analysis of specific fire
scenarios (3.19) or through the quantification of risk for a group of fire scenarios
[ISO/IEC 13943, definition 4.126]
3.19
fire scenario
qualitative description of the course of a fire (3.13) with respect to time, identifying key events
that characterise the studied fire and differentiate it from other possible fires

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60695-1-11 © IEC:2010 – 11 –
NOTE It typically defines the ignition (3.28) and fire growth (3.15) processes, the fully developed fire stage, the
fire decay stage, and the environment (3.7) and systems that will impact on the course of the fire.
[ISO/IEC 13943, definition 4.129]
3.20
fire test
test that measures behaviour of a fire (3.11) or exposes an item to the effects of a fire (3.12)
NOTE The results of a fire test can be used to quantify fire severity or determine the fire resistance or reaction to
fire (3.34) of the test specimen.
[ISO/IEC 13943, definition 4.132]
3.21
flame front
boundary of flaming combustion at the surface of a material or propagating through a gaseous
mixture
[ISO/IEC 13943, definition 4.136]
3.22
flame spread
propagation of a flame front (3.21)
[ISO/IEC 13943, definition 4.142]
3.23
flashover
〈stage of fire〉 transition to a state of total surface involvement in a fire (3.13) of combustible
materials within an enclosure
[ISO/IEC 13943, definition 4.156]
3.24
fractional effective dose
FED
ratio of the exposure dose (3.9) for an asphyxiant (3.1) to that exposure dose of the
asphyxiant expected to produce a specified effect on an exposed subject of average
susceptibility
NOTE 1 As a concept, fractional effective dose may refer to any effect, including incapacitation, lethality or other
endpoints.
NOTE 2 When not used with reference to a specific asphyxiant, the term FED represents the summation of FED
values for all asphyxiants in a combustion atmosphere.
NOTE 3 The FED is dimensionless.
[ISO/IEC 13943
...