SIST EN 60695-1-21:2017

Fire hazard testing - Part 1-21: Guidance for assessing the fire hazard of electrotechnical products - Ignitability - Summary and relevance of test methods (IEC 60695-1-21:2016)

IEC 60695-1-21:2016 provides a summary of test methods that are used to determine the ignitability of electrotechnical products or materials from which they are formed. It also includes test methods in which, by design, ignitability is a significant quantifiable characteristic. It represents the current state of the art of the test methods and, where available, includes special observations on their relevance and use. The list of test methods is not to be considered exhaustive, and test methods which were not developed by the IEC are not to be considered as endorsed by the IEC unless this is specifically stated. This basic safety publication is primarily 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. It is not intended for use by manufacturers or certification bodies. This first edition of IEC 60695-1-21 cancels and replaces the first edition of IEC TR 60695-1-21 published in 2008. It constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
- Change from a TR to an international standard;
- Modified Introduction;
- Modified Scope;
- Updated normative references;
- Updated terms and definitions;
- Updates and new text in Clause 4;
- Addition of text concerning ASTM D 3638;
- Updates to Annex A and Updates to the bibliography.
Key words: Fire Hazard, Fire Safety Engineering, Ignitability.

Prüfungen zur Beurteilung der Brandgefahr - Teil 1-21: Anleitung zur Beurteilung der Brandgefahr von elektrotechnischen Erzeugnissen - Entzündbarkeit - Zusammenfassung und Bedeutung der Prüfverfahren

Essais relatifs aux risques du feu - Partie 1-21: Lignes directrices pour l'évaluation des risques du feu des produits électrotechniques - Allumabilité - Résumé et pertinence des méthodes d'essais

L'IEC 60695-1-21:2016 donne un résumé des méthodes d'essai qui sont utilisées pour déterminer l'allumabilité des produits électrotechniques ou des matériaux à partir desquels ils sont fabriqués. Elle inclut également les méthodes d'essai pour lesquelles, par conception, l'allumabilité est une caractéristique quantifiable significative. Elle représente l'état de l'art de ces méthodes d'essai et, lorsque cela est applicable, inclut des observations spéciales concernant leur pertinence et leur utilisation. La liste des méthodes d'essai ne doit pas être considérée comme exhaustive et les méthodes d'essai qui n'ont pas été élaborées par l'IEC ne doivent pas être considérées comme étant entérinées par l'IEC sauf si cela est spécifiquement indiqué. La présente publication fondamentale de sécurité est destinée à être utilisée par les comités d'études pour l'élaboration de leurs normes conformément aux principes exposés dans le Guide IEC 104 et dans le Guide ISO/IEC 51. Elle n'est pas destiné à l'usage par des fabricants ou par des organismes de certification. Cette première édition de l'IEC 60695-1-21 annule et remplace la première édition de l'IEC TR 60695-1-21 parue en 2008. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- Changement d'un TR à une norme internationale;
- Introduction modifiée;
- Domaine d'application modifié;
- Références normatives mises à jour;
- Termes et définitions mis à jour;
- Mises à jour et nouveau texte dans l'Article 4;
- Complément de texte concernant l'ASTM D 3638;
- Mises à jour de l'Annexe A et mises à jour de la bibliographie.
Mots clés: Risques du feu, l'ingénierie de la sécurité incendie, Allumabilité

Preskušanje požarne ogroženosti - 1-21. del: Navodilo za ocenjevanje požarne ogroženosti elektrotehničnih izdelkov - Vžigljivost - Povzetek in pomen preskusnih metod (IEC 60695-1-21:2016)

Ta del standarda IEC 60695 zagotavlja pregled preskusnih metod, ki se uporabljajo za določevanje vžigljivosti elektrotehničnih izdelkov ali materialov, iz katerih so izdelani. Vključuje tudi preskusne metode, ki so zasnovane tako, da je vžigljivost pomembna merljiva lastnost.
Predstavlja trenutno najbolj izpopolnjene preskusne metode in vsebuje dodatna opažanja glede njihove primernosti in uporabe, če so na voljo. Seznam preskusnih metod ni popoln in preskusnih metod, ki jih ni razvil IEC, slednji ne podpira, razen če je navedeno drugače.
Ta osnovna varnostna publikacija je namenjena tehničnim odborom za pripravo standardov v skladu z načeli vodil IEC 104 in ISO/IEC 51.
Ena od pristojnosti tehničnih odborov je, da med pripravo publikacij uporabljajo osnovne varnostne publikacije, kadar je to primerno.

General Information

• Status: Published
• Publication Date: 28-Nov-2016
• ICS: 13.220.40 - Ignitability and burning behaviour of materials and products
• ICS: 29.020 - Electrical engineering in general
• Technical Committee: I09 - Imaginarni 09
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 16-Nov-2016
• Due Date: 21-Jan-2017
• Completion Date: 29-Nov-2016
• Ref Project: EN 60695-1-21:2016 - Fire hazard testing - Part 1-21: Guidance for assessing the fire hazard of electrotechnical products - Ignitability - Summary and relevance of test methods

Standards Content (Sample)

SLOVENSKI STANDARD
01-januar-2017
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RJURåHQRVWLHOHNWURWHKQLþQLKL]GHONRY9åLJOMLYRVW3RY]HWHNLQSRPHQSUHVNXVQLK
PHWRG,(&
Fire hazard testing - Part 1-21: Guidance for assessing the fire hazard of electrotechnical
products - Ignitability - Summary and relevance of test methods (IEC 60695-1-21:2016)
Essais relatifs aux risques du feu - Partie 1-21: Lignes directrices pour l'évaluation des
risques du feu des produits électrotechniques - Allumabilité - Résumé et pertinence des
méthodes d'essais
Ta slovenski standard je istoveten z: EN 60695-1-21:2016
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
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 60695-1-21

NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2016
ICS 29.020; 13.220.40
English Version
Fire hazard testing - Part 1-21: Guidance for assessing the fire
hazard of electrotechnical products - Ignitability - Summary and
relevance of test methods
(IEC 60695-1-21:2016)
Essais relatifs aux risques du feu - Partie 1-21: Lignes Prüfungen zur Beurteilung der Brandgefahr - Teil 1-21:
directrices pour l'évaluation des risques du feu des produits Anleitung zur Beurteilung der Brandgefahr von
électrotechniques - Allumabilité - Résumé et pertinence des elektrotechnischen Erzeugnissen - Entzündbarkeit -
méthodes d'essais Zusammenfassung und Bedeutung der Prüfverfahren
(IEC 60695-1-21:2016) (IEC 60695-1-21:2016)
This European Standard was approved by CENELEC on 2016-10-12. CENELEC 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 CENELEC 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 CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 60695-1-21:2016 E
European foreword
The text of document 89/1336/FDIS, future edition 1 of IEC 60695-1-21, prepared by IEC/TC 89 "Fire
hazard testing" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN
60695-1-21:2016.
The following dates are fixed:
(dop) 2017-07-12
• latest date by which the document has to be
implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2019-10-12
standards conflicting with the
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
Endorsement notice
The text of the International Standard IEC 60695-1-21:2016 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:

ISO 11357 (Series) NOTE Harmonized as EN ISO 11357 (Series).
ISO 4589-1:1996 NOTE Harmonized as EN ISO 4589-1:1999.
ISO 4589-2:1996 NOTE Harmonized as EN ISO 4589-2:1999.
ISO 4589-3:1996 NOTE Harmonized as EN ISO 4589-3:1999.

Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod), the relevant

EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60695-1-20 -  Fire hazard testing - Part 1-20: Guidance EN 60695-1-20 -
for assessing the fire hazard of
electrotechnical products - Ignitability -
General guidance
IEC 60695-1-30 -  Fire hazard testing -- Part 1-30: Guidance EN 60695-1-30 -
for assessing the fire hazard of
electrotechnical products - Preselection
testing process - General guidelines
IEC 60695-4 2012 Fire hazard testing -- Part 4: Terminology EN 60695-4 2012
concerning fire tests for electrotechnical
products
IEC Guide 104 -  The preparation of safety publications and - -
the use of basic safety publications and
group safety publications
ISO 13943 2008 Fire safety - Vocabulary EN ISO 13943 2010
ISO/IEC Guide 51 -  Safety aspects - Guidelines for their - -
inclusion in standards
IEC 60695-1-21 ®
Edition 1.0 2016-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ

Fire hazard testing –
Part 1-21: Guidance for assessing the fire hazard of electrotechnical products –

Ignitability – Summary and relevance of test methods

Essais relatifs aux risques du feu –

Partie 1-21: Lignes directrices pour l’évaluation des risques du feu des produits

électrotechniques – Allumabilité – Résumé et pertinence des méthodes d'essais

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 13.220.40, 29.020 ISBN 978-2-8322-3617-8

– 2 – IEC 60695-1-21:2016  IEC 2016
CONTENTS
FOREWORD .3
INTRODUCTION .5
1 Scope .7
2 Normative references .7
3 Terms and definitions .8
4 Summary of published test methods . 12
4.1 General . 12
4.2 Tests using heated air or electrical heating . 12
4.2.1 Determination of ignition temperature using a hot-air furnace, ISO 871 . 12
4.2.2 Differential scanning calorimetry (DSC), ISO 11357 [1] . 13
4.3 Tests using radiant heat . 14
4.3.1 Heat release rate – Cone calorimeter method, ISO 5660-1 [4] . 14
4.3.2 Heat release of insulating liquids, IEC TS 60695-8-3 [5] . 15
4.3.3 Standard test method for determining material ignition and flame
spread properties, ASTM E 1321 [6] . 16
4.3.4 Determination of the characteristic heat flux for ignition from a non-
contacting flame source, IEC TS 60695-11-11 [7] . 17
4.4 Oxygen index tests . 17
4.4.1 Oxygen index – Ambient temperature test, ISO 4589-2 [8] . 17
4.4.2 Oxygen index – Elevated temperature test, ISO 4589-3 [10] . 18
4.5 Glowing/hot-wire based test methods . 20
4.5.1 Glow wire tests, IEC 60695-2-11 [14], IEC 60695-2-12 [15] and
IEC 60695-2-13 [16] . 20
4.5.2 Hot wire coil ignitability test, IEC 60695-2-20 and ASTM D 3874 [17] . 22
4.6 Flame tests . 23
4.6.1 Needle flame test, IEC 60695-11-5 [18] . 23
4.6.2 50 W Horizontal and vertical flame test methods, IEC 60695-11-10 [19]
500 W flame test methods, IEC 60695-11-20 [20] . 24
4.6.3 1 kW nominal pre-mixed flame, IEC 60695-11-2 [23] . 25
4.6.4 Vertical and 60° tests for aircraft components, FAR 25 [25] . 25
4.7 Tests using an electrical arc . 26
4.7.1 Tracking index tests, IEC 60112 [26], ASTM D 3638 [27] . 26
4.7.2 High-Current Arc Ignition (HAI), UL 746A – Sec. 32 [30] . 28
4.7.3 High-voltage arc resistance to ignition (HVAR), UL 746A – Sec. 33 [31] . 28
Annex A (informative) Applicability of test methods . 30
A.1 Applicability of test methods . 30
Bibliography . 32

Table 1 – Main differences between IEC 60112 and ASTM D 3638 . 27
Table A.1 – Applicability of test methods (1 of 2) . 30

IEC 60695-1-21:2016  IEC 2016 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FIRE HAZARD TESTING –
Part 1-21: Guidance for assessing
the fire hazard of electrotechnical products –
Ignitability – Summary and relevance of test methods

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 60695-1-21 has been prepared by IEC technical committee 89:
Fire hazard testing.
The text of this standard is based on the following documents:
FDIS Report on voting
89/1336/FDIS 89/1339/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.

– 4 – IEC 60695-1-21:2016  IEC 2016
It has the status of a basic safety publication in accordance with IEC Guide 104 and
ISO/IEC Guide 51.
This first edition of IEC 60695-1-21 cancels and replaces the first edition of
IEC TR 60695-1-21 published in 2008. It constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) Change from a TR to an international standard;
b) Modified Introduction;
c) Modified Scope;
d) Updated normative references;
e) Updated terms and definitions;
f) Updates and new text in Clause 4;
g) Addition of text concerning ASTM D 3638;
h) Updates to Annex A;
i) Updates to the bibliography.
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.
The IEC 60695-1 series, under the general title Fire hazard testing, 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 1-12: Guidance for assessing the fire hazard of electrotechnical products – Fire safety
engineering
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 procedures – 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.
IEC 60695-1-21:2016  IEC 2016 – 5 –
INTRODUCTION
Fires are responsible for creating hazards to life and property as a result of the generation of
heat (thermal hazard), and also as a result of the production of toxic effluent, corrosive
effluent and smoke (non-thermal hazard). Fires start with ignition and then can grow, leading
in some cases to flash-over and a fully developed fire. Ignition resistance is therefore one of
the most important parameters of a material to be considered in the assessment of fire
hazard. If there is no ignition, there is no fire.
For most materials (other than metals and some other elements), ignition occurs in the gas
phase. Ignition occurs when combustible vapour, mixed with air, reaches a high enough
temperature for exothermic oxidation reactions to rapidly propagate. The ease of ignition is a
function of the chemical nature of the vapour, the fuel/air ratio and the temperature.
In the case of liquids, the combustible vapour is produced by vaporization of the liquid, and
the vaporization process is dependent on the temperature and chemical composition of the
liquid.
In the case of solids, the combustible vapour is produced by pyrolysis when the temperature
of the solid is sufficiently high. The vaporization process is dependent on the temperature
and chemical composition of the solid, and also on the thickness, density, specific heat, and
thermal conductivity of the solid.
The ease of ignition of a test specimen depends on many variables. Factors that need to be
considered for the assessment of ignitability are:
a) the geometry of the test specimen, including thickness and the presence of edges,
corners or joints;
b) the surface orientation;
c) the rate and direction of air flow;
d) the nature and position of the ignition source;
e) the magnitude and position of any external heat flux; and
f) whether the combustible material is a solid or a liquid.
In the design of an 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 the risk of fire to a
tolerable level even in the event of reasonably foreseeable (mis)use, malfunction or failure.
Fires involving electrotechnical products can also be initiated from external non-electrical
sources. Considerations of this nature are dealt with in an overall fire hazard assessment.
The aim of the IEC 60695 series of standards is to save lives and property by reducing the
number of fires or reducing the consequences of the fire. This can be accomplished by:
• trying 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.
• trying to minimise flame spread beyond the product’s enclosure and to minimise the
harmful effects of fire effluents including heat, smoke, and toxic or corrosive combustion
products.
For these reasons there are many tests used to evaluate the ignitability of electrotechnical
products and of the materials used in their construction. This part of IEC 60695 describes
ignitability test methods in common use to assess electrotechnical products, or materials
used in electrotechnical products. It also includes test methods in which, by design,

– 6 – IEC 60695-1-21:2016  IEC 2016
ignitability is a significant quantifiable characteristic. It forms part of the IEC 60695-1 series,
which gives guidance to product committees wishing to incorporate fire hazard test methods
in product standards.
IEC 60695-1-21:2016  IEC 2016 – 7 –
FIRE HAZARD TESTING –
Part 1-21: Guidance for assessing
the fire hazard of electrotechnical products –
Ignitability – Summary and relevance of test methods

1 Scope
This part of IEC 60695 provides a summary of test methods that are used to determine the
ignitability of electrotechnical products or materials from which they are formed. It also
includes test methods in which, by design, ignitability is a significant quantifiable
characteristic.
It represents the current state of the art of the test methods and, where available, includes
special observations on their relevance and use. The list of test methods is not to be
considered exhaustive, and test methods which were not developed by the IEC are not to be
considered as endorsed by the IEC unless this is specifically stated.
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.
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.
IEC 60695-1-20, Fire hazard testing – Part 1-20: Guidance for assessing the fire hazard of
electrotechnical products – Ignitability – General guidance
IEC 60695-1-30, Fire hazard testing – Part 1-30: Guidance for assessing the fire hazard of
electrotechnical products – Use of preselection testing procedures
IEC 60695-4:2012, Fire hazard testing – Part 4: Terminology concerning fire tests for
electrotechnical products
IEC Guide 104, The preparation of safety publications and the use of basic safety
publications and group safety publications
ISO/IEC Guide 51, Safety aspects – Guidelines for their inclusion in standards
ISO 13943:2008, Fire safety – Vocabulary

– 8 – IEC 60695-1-21:2016  IEC 2016
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 13943:2008 and
IEC 60695-4:2012 (some of which are reproduced below) and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
combustion
exothermic reaction of a substance with an oxidizing agent
Note 1 to entry: Combustion generally emits fire effluent accompanied by flames (3.10) and/or glowing.
[SOURCE: ISO 13943:2008, 4.46]
3.2
end product
product that is ready for use without modification
Note 1 to entry: An end product can be a component of another end product.
[SOURCE: IEC 60695-4:2012, 3.2.7]
3.3
fire
〈general〉 process of combustion (3.1) characterized by the emission of heat and fire effluent
and usually accompanied by smoke, flame (3.10), glowing or a combination thereof
Note 1 to entry: In the English language the term “fire” is used to designate three concepts, two of which, fire
(3.4) and fire (3.5), 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.
[SOURCE: ISO 13943:2008, 4.96]
3.4
fire
〈controlled〉 self-supporting combustion (3.1) that has been deliberately arranged to provide
useful effects and is limited in its extent in time and space
[SOURCE: ISO 13943:2008, 4.97]
3.5
fire
〈uncontrolled〉 self-supporting combustion (3.1) that has not been deliberately arranged to
provide useful effects and is not limited in its extent in time and space
[SOURCE: ISO 13943:2008, 4.98]
3.6
fire hazard
physical object or condition with a potential for an undesirable consequence from fire (3.3)
[SOURCE: ISO 13943:2008, 4.112]

IEC 60695-1-21:2016  IEC 2016 – 9 –
3.7
fire point
minimum temperature at which a material ignites and continues to burn for a specified time
after a standardized small flame (3.10) has been applied to its surface under specified
conditions
cf. flash point (3.15)
Note 1 to entry: In some countries the term "fire point" has an additional meaning: a location where fire fighting
equipment is sited, which may also comprise a fire-alarm call point and fire instruction notices.
Note 2 to entry: The typical units are degrees Celsius (°C).
[SOURCE: ISO 13943:2008, 4.119]
3.8
fire retardant, noun
substance added or a treatment applied to a material in order to delay ignition (3.19) or to
reduce the rate of combustion (3.1)
cf. flame retardant (3.11)
Note 1 to entry: The use of (a) fire retardant(s) does not necessarily suppress fire (3.3) or terminate combustion
(3.1).
[SOURCE: ISO 13943:2008, 4.123]
3.9
fire scenario
qualitative description of the course of a fire (3.5) with respect to time, identifying key events
that characterise the studied fire and differentiate it from other possible fires
Note 1 to entry: It typically defines the ignition (3.19) and fire growth processes, the fully developed fire (3.16)
stage, the fire decay stage, and the environment and systems that impact on the course of the fire.
[SOURCE: ISO 13943:2008, 4.129]
3.10
flame, noun
zone in which there is rapid, self-sustaining, sub-sonic propagation of combustion (3.1) in a
gaseous medium, usually with emission of light
[SOURCE: ISO 13943:2008, 4.133, modified (addition of “zone in which there is”)]
3.11
flame retardant, noun
substance added, or a treatment applied, to a material in order to suppress or delay the
appearance of a flame (3.10) and/or reduce the flame spread rate
cf. fire retardant (3.8)
Note 1 to entry: The use of (a) flame retardant(s) does not necessarily suppress fire (3.3) or terminate
combustion (3.1).
[SOURCE: ISO 13943:2008, 4.139]
3.12
flaming combustion
combustion (3.1) in the gaseous phase, usually with emission of light

– 10 – IEC 60695-1-21:2016  IEC 2016
[SOURCE: ISO 13943:2008, 4.148]
3.13
flash-ignition temperature
FIT
minimum temperature at which, under specified test conditions, sufficient flammable gases
are emitted to ignite momentarily on application of a pilot flame (3.10)
[SOURCE: ISO 871:2006, 3.1]
3.14
flash-over
〈stage of fire〉 transition to a state of total surface involvement in a fire (3.3) of combustible
materials within an enclosure
[SOURCE: ISO 13943:2008, 4.157]
3.15
flash point (ºC)
minimum temperature to which it is necessary to heat a material or a product for the vapours
emitted to ignite momentarily in the presence of flame (3.10), under specified test conditions
Note 1 to entry: The typical units are degrees Celsius (°C).
[SOURCE: ISO 13943:2008, 4.154]
3.16
fully developed fire
state of total involvement of combustible materials in a fire (3.5)
[SOURCE: ISO 13943:2008, 4.164]
3.17
glowing combustion
combustion (3.1) of a material in the solid phase without flame (3.10) but with emission of
light from the combustion zone
[SOURCE: ISO 13943:2008, 4.169]
3.18
ignitability
ease of ignition
measure of the ease with which a test specimen can be ignited, under specified conditions
[SOURCE: ISO 13943:2008, 4.182]
3.19
ignition
sustained ignition (deprecated)
〈general〉 initiation of combustion (3.1)
[SOURCE: ISO 13943:2008, 4.187]
3.20
ignition
sustained ignition (deprecated)
〈flaming combustion〉 initiation of sustained flame (3.10)

IEC 60695-1-21:2016  IEC 2016 – 11 –
[SOURCE: ISO 13943:2008, 4.188]
3.21
ignition source
source of energy that initiates combustion (3.1)
[SOURCE: ISO 13943:2008, 4.189]
3.22
lower flammability limit
LFL
minimum concentration of fuel vapour in air below which propagation of a flame (3.10) does
not occur in the presence of an ignition source (3.21)
Note 1 to entry: The concentration is usually expressed as a volume fraction at a defined temperature and
pressure, and expressed as a percentage.
[SOURCE: ISO 13943:2008, 4.216]
3.23
minimum ignition temperature
ignition point
minimum temperature at which sustained combustion (3.1) can be initiated under specified
test conditions
Note 1 to entry: The minimum ignition temperature implies the application of a thermal stress for an infinite length
of time.
Note 2 to entry: The typical units are degrees Celsius (°C).
[SOURCE: ISO 13943:2008, 4.231]
3.24
spontaneous-ignition temperature
SIT
minimum temperature at which ignition (3.19) is obtained by heating, under specified test
conditions, in the absence of any additional flame (3.10) ignition source (3.21)
[SOURCE: ISO 871, 3.2]
3.25
thermal inertia
product of thermal conductivity, density and specific heat capacity
8 2 -1 -4 -2
EXAMPLES The thermal inertia of steel is 2,3 × 10 J ⋅s ⋅m ⋅K . The thermal inertia of polystyrene foam is
3 2 -1 -4 -2
1,4 × 10 J ⋅s ⋅m ⋅K .
Note 1 to entry: When a material is exposed to a heat flux, the rate of increase of surface temperature depends
strongly on the value of the thermal inertia of the material. The surface temperature of a material with a low
thermal inertia rises relatively quickly when it is heated, and vice versa.
Note 2 to entry: The typical units are joules squared per second per metre to the fourth power per Kelvin squared
2 -1 -4 -2
(J ⋅s ⋅m ⋅K ).
[SOURCE: ISO 13943:2008, 4.326]

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3.26
tracking
arc tracking
〈electrotechnical〉 progressive formation of conducting paths that are produced on the surface
and/or within a solid insulating material, due to the combined effects of electric stress and
electrolytic contamination
[SOURCE: ISO 13943:2008, 4.342]
3.27
upper flammability limit
UFL
maximum concentration of fuel vapour in air above which propagation of a flame (3.10) will
not occur in the presence of an ignition source (3.21)
Note 1 to entry: The concentration is usually expressed as a volume fraction at a defined temperature and
pressure, and expressed as a percentage.
[SOURCE: ISO 13943:2008, 4.349]
4 Summary of published test methods
4.1 General
This summary cannot be used in place of published standards which are the only valid
reference documents. It represents the current state of the art of the test methods and, where
available, includes special observations on their relevance and use. The list of test methods
is not to be considered exhaustive, and test methods which were not developed by the IEC
are not to be considered as endorsed by the IEC unless this is specifically stated. General
guidance on ignitability is given in IEC 60695-1-20.
Some test methods are material tests and some are end product tests. Table A.1 lists the test
methods described below and distinguishes between material tests and end product tests.
In cases where fire tests are not yet specified, and need to be developed or altered for the
special purpose of an IEC technical committee, this shall be done in liaison with IEC
Technical Committee 89.
The test method(s) selected shall be relevant to the fire scenario of concern.
NOTE 1 Not all the following test methods are specifically ignition or ignitability tests, but some tests have been
included because ignition data are, or can be, measured.
NOTE 2 Where no repeatability and reproducibility data are known to be available, information may be available
from the author/publisher of the relevant test method.
4.2 Tests using heated air or electrical heating
4.2.1 Determination of ignition temperature using a hot-air furnace, ISO 871
4.2.1.1 Purpose and principle
ISO 871 specifies a laboratory method for determining the flash-ignition temperature and
spontaneous-ignition temperature of plastics using a hot-air furnace.
A specimen of the material is heated in a hot-air ignition furnace using various temperatures
within the heated chamber, and the flash-ignition temperature is determined with a small pilot
flame directed at the opening in the top of the furnace to ignite evolved gases. The
spontaneous-ignition temperature is determined in the same manner as the flash-ignition
temperature, but without the ignition flame.

IEC 60695-1-21:2016  IEC 2016 – 13 –
4.2.1.2 Test specimen
Materials supplied in any form, including composites, may be used. A 3 g sample is used if
-3
the density is greater than 100 kg⋅m . For cellular materials having a density less than
-3
100 kg⋅m , any outer skin is removed and a block of dimensions 20 mm × 20 mm × 50 mm is
cut.
4.2.1.3 Test method
-1
An air velocity of 25 mm⋅s is set and an initial test temperature is chosen. At the end of
10 min the temperature is lowered or raised by 50 °C, depending on whether ignition has or
has not occurred and a fresh sample is tested. When the range within which the ignition
temperature lies has been determined, tests are begun 10 °C below the highest temperature
within this range and continued by dropping the temperature in 10 °C steps until the
temperature is reached at which there is no ignition during a 10 min period. The ignition
temperature is recorded as the lowest test temperature at which ignition is observed.
4.2.1.4 Repeatability and reproducibility
Data are available in Annex A of ISO 871:2006.
4.2.1.5 Relevance of test data
Tests made under the conditions of this method can be of considerable value in comparing
the relative ignition characteristics of different materials. Values obtained represent the
lowest ambient air temperature that will cause ignition of the material under the conditions of
this test. Test values are expected to rank materials according to ignition susceptibility under
actual use conditions.
4.2.2 Differential scanning calorimetry (DSC), ISO 11357 [1]
4.2.2.1 Introduction
Differential scanning calorimetry (DSC) is one of a number of thermal methods of analysis
which are not used to directly measure ignition, but which are used to measure a number of
properties which affect ignitability and which can be used in fire safety engineering studies
and in fire modelling.
NOTE Other useful techniques include thermogravimetric analysis (TGA), differential thermal analysis (DTA),
thermomechanical analysis (TMA), dynamic mechanical thermal analysis (DMTA), and pyrolysis gas
chromatography [2], [3].
4.2.2.2 Purpose and principle
ISO 11357 consists of seven parts, and describes methods using DSC to measure the
following properties of polymeric materials such as thermoplastics and thermosetting plastics,
including moulded materials and composite materials:
• Glass transition temperature
• Temperature and enthalpy of melting and crystallization
• Specific heat capacity
• Polymerization temperatures and/or times and polymerization kinetics
• Oxidation induction time
• Crystallization kinetics
___________
Numbers in square brackets refer to the bibliography.

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The DSC method involves the measurement of the difference between the heat flow into a
test specimen and that into a reference specimen as a function of temperature and/or time,
while the test specimen and the reference specimen are subjected to a controlled
temperature programme under a specified atmosphere.
4.2.2.3 Test specimen
Test specimens may be liquid or solid. The optimum test specimen mass varies depending on
what parameter is being studied, but will typically be in the range 5 mg to 50 mg. The test
specimen is placed in a sample pan which, if required, is sealed with a lid. The reference
specimen is usually an identical empty sample pan.
4.2.2.4 Test method
The instrument is first calibrated, then the sample pans are inserted and the instrument is
programmed to carry out the desired thermal cycle. Control operations and data analysis are
according to the manufacturer’s instructions.
4.2.2.5 Repeatability and reproducibility
Data are given in annexes to the various parts of ISO 11357.
4.2.2.6 Relevance of test data
DSC enables the measurement of two important parameters which are needed in fire models
of ignition. These are: a) specific heat capacity as a function of temperature, and b) the heat
of gasification.
4.3 Tests using radiant heat
4.3.1 Heat release rate – Cone calorimeter method, ISO 5660-1 [4]
4.3.1.1 Purpose and principle
ISO 5660-1 specifies a method for assessing the heat release rate, smoke production rate
and mass loss rate of a test specimen exposed in the horizontal orientation to a controlled
level of irradiance in the presence of a spark ignition source. The irradiance is within the
-2 -2
range of 0 kW × m to 100 kW × m . The heat release rate is determined by measurement
of the oxygen consumption derived from the oxygen concentration and the flow rate in the
combustion product stream. The time to ignition (sustained flaming) is also measured in the
test. The test specimen is mounted on a load cell so that the mass is measured during the
test.
The test method is based on the observation that, generally, the net heat of combustion is
proportional to the amount of oxygen required for combustion. The relationship is that
approximately 13,1 kJ of heat are released per gram of oxygen consumed.
4.3.1.2 Test specimen
The test specimen is square (100 mm × 100 mm) and not more than 50 mm thick. It is
wrapped in aluminium foil so that the bottom and sides are covered and the top surface is
exposed. The wrapped test specimen is placed in a retainer frame. A substrate is used if
appropriate.
4.3.1.3 Test method
The apparatus is first calibrated, and then the exhaust flow and irradiance levels are set. The
test specimen is placed in position under a radiation shield, and then the test is started when
the shield is removed and the spark igniter is inserted and powered.

IEC 60695-1-21:2016  IEC 2016 – 15 –
Data are collected for typically 32 min after sustained flaming has occurred. Three specimens
are tested.
4.3.1.4 Repeatability and reproducibility
Data are available in Annex B of ISO 5660-1:2015.
4.3.1.5 Relevance of test data
Heat release rate is one of the most important variables in determining the hazard from a fire.
In a typical fire, many items composed of many surfaces contribute to the development of a
fire, thus making its evaluation quite complex. A determination must first be made of when
each separate surface will ignite, if at all, and this bench scale test gives this information.
The size of the fire from any items already burning must be determined in order to calculate
its contribution to the external irradiance on nearby items. Flame spread over each surface
must also be evaluated. The heat release rate from the whole surface is then determined
knowing the heat release rate per unit area for a given irradiance, as a function of time, as
evaluated using this bench scale test. The total fire output then involves a summation over all
surfaces for all materials.
Ignition time data as a function of irradiance can also be used to calculate useful ignition
related parameters such as the thermal inertia of materials.
4.3.2 Heat release of insulating liquids, IEC TS 60695-8-3 [5]
4.3.2.1 Purpose and principle
This technical specification specifies test methods for determining the heat release and
smoke production from insulating liquids of electrotechnical products when exposed to a
defined heat flux. The technical specification may also be applicable to other liquid
specimens.
The principle of the method is the same as that described in 4.2.1.1. In addition a laser,
shining through the exhaust effluent, is used to measure smoke production, as described in
ISO 5660-1.
4.3.2.2 Test specimen
3 3
For preliminary tests 20 cm of liquid are used. 50 cm of liquid are used for the main tests.
The liquid is placed in a square, stainless steel sample holder which is 100 mm × 100 mm
and 15 mm deep.
4.3.2.3 Test method
The apparatus is calibrated in accordance with ISO 5660-1 and preliminary tests are carried
out to find the minimum heat flux (critical ignition flux) at which the test specimen ignites in
less than 1 200 s. The main tests are then carried out at this critical ignition flux. Data
analysis is in accordance with ISO 5660-1.
4.3.2.4 Repeatability and reproducibility
No data are currently available.
___________
Withdrawn in 2015.
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4.3.2.5 Relevance of test data
From this test it is possible to obtain a quantitative assessment of the relative ease, or
difficulty, of the ignition of liquids used for electrotechnical purposes. Quantitative heat
release and smoke production data are also obtained. All these data can be used in fire
safety engineering studies including fire hazard assessments.
4.3.3 Standard test method for determining material ignition and flame spread
properties, ASTM E 1321 [6]
4.3.3.1 Purpose and principle
ASTM E 1321 determines material properties related to piloted ignition of a vertically oriented
sample under a constant and uniform heat flux and to lateral flame spread on a vertical
surface due to an externally applied radiant-heat flux.
4.3.3.2 Test specimen
Test specimens are tested in the form of intended use. For the ignition test, specimens are
155 mm × 155 mm. For the flame spread test, specimens are 800 mm × 155 mm. For both
tests, materials and composites of normal thickness 50 mm or less are tested using their full
thickness. The test method is restricted to thermally thick test specimens (i.e. when the
exposed surface has ignited, the back surface will not have become significantly heated
above the ambient temperature).
4.3.3.3 Test method
The test method consist
...