IEC 60332-1-2:2025

IEC 60332-1-2 ®
Edition 2.0 2025-06
COMMENTED VERSION
INTERNATIONAL
STANDARD
Tests on electric and optical fibre cables under fire conditions –
Part 1-2: Test for vertical flame propagation for a single insulated wire or cable –
Procedure for 1 kW pre-mixed flame
ICS 13.220.40; 29.020; 29.060.20 ISBN 978-2-8327-0502-5
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CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Test apparatus . 6
5 Procedure . 6
5.1 Sample . 6
5.2 Conditioning . 6
5.3 Positioning of test piece . 7
5.4 Flame application . 7
5.4.1 Safety warning . 7
5.4.2 Positioning of flame . 7
5.4.3 Test duration . 8
6 Evaluation of test results . 8
7 Performance requirements. 8
Annex A(informativenormative) Recommended Performance requirements . 12
Bibliography . 13
List of comments . 14

Figure 1 – Arrangement of test piece in test apparatus . 9
Figure 2 – Application of flame to test piece . 11

Table 1 – Time for flame application . 8
Table A.1 – Performance requirements . 12

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
TESTS ON ELECTRIC AND OPTICAL FIBRE CABLES
UNDER FIRE CONDITIONS –
Part 1-2: Test for vertical flame propagation for a single insulated wire
or cable – Procedure for 1 kW pre-mixed flame

FOREWORD
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This commented version (CMV) of the official standard IEC 60332-1-2:2025 edition 2.0
allows the user to identify the changes made to the previous IEC 60332-1-2:2004+
AMD1:2015 CSV edition 1.1. Furthermore, comments from IEC TC 20 experts are provided
to explain the reasons of the most relevant changes, or to clarify any part of the content.
A vertical bar appears in the margin wherever a change has been made. Additions are in
green text, deletions are in strikethrough red text. Experts' comments are identified by a
blue-background number. Mouse over a number to display a pop-up note with the
comment.
This publication contains the CMV and the official standard. The full list of comments is
available at the end of the CMV.

– 4 – IEC 60332-1-2:2025 CMV © IEC 2025
IEC 60332-1-2 has been prepared by IEC technical committee 20: Electric cables. It is an
International Standard.
This second edition cancels and replaces the first edition published in 2004 and
Amendment 1:2015. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) modification in positioning of test pieces, which move out of the flame (5.3);
b) addition of performance requirements (Annex A).
The text of this International Standard is based on the following documents:
Draft Report on voting
20/2232/FDIS 20/2244/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
This document has the status of a group safety publication in accordance with IEC Guide 104.
A list of all parts in the IEC 60332 series, published under the general title Tests on electric and
optical fibre cables under fire conditions, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
TESTS ON ELECTRIC AND OPTICAL FIBRE CABLES
UNDER FIRE CONDITIONS –
Part 1-2: Test for vertical flame propagation for a single insulated wire
or cable – Procedure for 1 kW pre-mixed flame

1 Scope
This part of IEC 60332 specifies the procedure for testing the resistance to vertical flame
propagation for a single vertical electrical insulated conductor or cable, or optical fibre cable,
under fire conditions using a 1 kW pre-mixed flame 1. The apparatus is described in
IEC 60332-1-1.
NOTE 1 Testing to IEC 60332-1-2 may can be performed simultaneously with that to IEC 60332-1-3, if required.
Recommended requirements for performance are given in Annex A.
IEC 60332-1-2 specifies the use of a 1 kW pre-mixed flame and is for general use, except that
the procedure specified may not be suitable for the testing of small single insulated conductors
or cables of less than 0,5 mm² total cross-section because the conductor melts before the test is
completed, or for the testing of small optical fibre cables because the cable is broken before the
test is completed. In these cases, the procedure given in IEC 60332-2-2 is recommended. 2
This group safety publication focusing on test method(s) is primarily intended to be used as a
product safety standard for the products mentioned in the scope, but is also intended to be used
by technical committees in the preparation of standards for products similar to those mentioned
in the scope of this group safety publication, in accordance with the principles laid down in
IEC Guide 104 and lSO/lEC Guide 51.
NOTE 2 Since the use of insulated conductor or cable which retards flame propagation and complies with the
recommended requirements of this standard is not sufficient by itself to prevent propagation of fire under all
conditions of installation, it is recommended that wherever the risk of propagation is high, for example in long vertical
runs of bunches of cables, special installation precautions should also be taken. It cannot be assumed that because
the sample of cable complies with the performance requirements recommended in this standard, that a bunch of
cables will behave in a similar manner. (See IEC 60332-3 series.) The performing of this test method on a single
insulated conductor or cable or optical fibre cable does not provide compliance with fire propagation requirements in
relevant standards in the case that the single insulated conductor or cable or optical fibre cable is installed with or
amongst other cables as a group. (See the IEC 60332-3 series). 3
One of the responsibilities of a technical committee is, wherever applicable, to make use of
basic safety publications and/or group 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 60332-1-1, Tests on electric and optical fibre cables under fire conditions – Part 1-1: Test
for vertical flame propagation for a single insulated wire or cable – Apparatus
IEC 60695-4, Fire hazard testing – Part 4: Terminology concerning fire tests

– 6 – IEC 60332-1-2:2025 CMV © IEC 2025
IEC 60811-203, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 203: General tests – Measurement of overall dimensions
IEC Guide 104, The preparation of safety publications and the use of basic safety publications
and group safety publications
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply. The definitions
are taken from IEC 60695-4.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
ignition source 4
source of energy that initiates combustion
[SOURCE: ISO 13943:2008, 1.489]
3.21
char, noun
carbonaceous residue resulting from pyrolysis or incomplete combustion
[SOURCE: ISO 13943:20082023, 4.38 3.53]
4 Test apparatus
The apparatus specified in IEC 60332-1-1 shall be used.
5 Procedure
5.1 Sample
The test sample shall be a piece of single insulated conductor or cable (600 ± 25) mm long.
The test sample diameter shall be measured using the method given in IEC 60811-203. The
measurement shall be made at each of three places, separated by at least 100 mm.
The average of the three values obtained shall be rounded to obtain the overall diameter. If the
calculation gives 5 or more for the second decimal figure, raise the first to the next number;
thus, for example, 5,75 is rounded to 5,8. If the calculation gives 4 or less for the second decimal
figure, maintain the first number; thus, for example, 5,74 is rounded to 5,7.
The overall diameter obtained shall be used for the selection of the time for flame application.
5.2 Conditioning
Before testing, all test pieces shall be conditioned at (23 ± 5) °C for not less than 16 h at a
relative humidity of (50 ± 20) %.

In the case of a single insulated conductor or cable with a finish of paint or lacquer, this
conditioning shall follow an initial period where the test piece shall be kept at a temperature of
(60 ± 2) °C for 4 h.
5.3 Positioning of test piece
The test piece shall be straightened and secured to two horizontal supports by means of a
suitable size of metal (copper or steel) wire, in a vertical position in the centre of the metal
enclosure, as described in IEC 60332-1-1, so that the distance between the bottom of the upper
support and the top of the lower support is (550 ± 5) mm. For cables up to and including 50 mm
diameter, metal wire of (1,0 ± 0,3) mm in diameter is recommended. For cables above 50 mm
diameter, metal wire of (1,5 ± 0,3) mm in diameter is recommended. 5
In addition, the test piece shall be positioned so that the bottom of the specimen is
approximately 50 mm from the base of the enclosure (see Figure 1).
The vertical axis of the test piece shall be arranged centrally within the enclosure (i.e. 150 mm
from each side and 225 mm from the rear).
The test is only valid if the test piece stays in the test flame during the whole test. 6
If the test piece moves out of the flame, for example because it breaks at the flame impact
point, the mounting, as described in the next paragraph, shall be applied.
The test piece shall be kept in the test flame by applying 1 mm diameter metal wire loops around
the test piece, approximately (50 ± 5) mm below as well as (50 ± 5) mm and (150 ± 5) mm
above the position of impingement of the blue cone, attached to the side walls of the metallic
enclosure or to a vertical rod or rail located in the back in the metallic enclosure. At the
beginning of the test these additional metal wire loops shall not touch the test piece. See
Figure 2.
The inner diameter of the wire loops shall exceed the cable diameter by at least 4,0 mm.
In the case of an electrical electric insulated conductor or cable, should the test piece move
significantly during the test so as to render the result invalid, the test piece shall be held straight
by the attachment of a load of approximately 5 N/mm of conductor area to the lower part of the
sample, so that the distance between the point where the load is attached and the lower edge
of the top support measures (550 ± 5) mm. In such cases, the test piece shall not be secured
to the lower support.
5.4 Flame application
5.4.1 Safety warning
WARNING – Safety precautions shall be taken to safeguard personnel against the following
when conducting tests:
a) the risk of fire or explosion;
b) the inhalation of smoke or noxious products, or both, particularly when halogenated
materials are burned;
c) harmful residues.
5.4.2 Positioning of flame
332-1-1, shall be ignited and the flow rates of gas and air
A burner, as described in IEC 60
adjusted to the specified values. The burner shall be positioned so that the tip of the blue cone
impinges on the surface of the test piece at a distance of (475 ± 5) mm from the lower edge of
the upper horizontal support, whilst the burner is at an angle of (45 ± 2)° to the vertical axis of

– 8 – IEC 60332-1-2:2025 CMV © IEC 2025
the test piece (see Figure 2). The burner position shall be fixed throughout the flame application
time.
For flat-form cables, the flame impingement shall be on the middle of the flat side of the cable.
5.4.3 Test duration
The flame shall be applied continuously for the period of time corresponding to the diameter
shown in Table 1.
Table 1 – Time for flame application
a
Time for flame application
Overall diameter of test piece
mm s
D ≤ 25 60 ± 2
25 < D ≤ 50 120 ± 2
50 < D ≤ 75 240 ± 2
D > 75 480 ± 2
a
For non-circular cables in which the major to minor axis ratio is less than 3, the
nominal minor axis shall be used as the overall diameter (D). For non-circular
cables in which the major to minor axis ratio lies between 3 and 16, the overall
diameter (D) shall be taken as the sum of the major and minor axis divided by
3,14 (π). For cables in which the major to minor axis ratio exceeds 16, the test
criteria shall be given in the product standard or, if not, agreed between the
manufacturer and purchaser.
At the end of the specified flame application time, the burner shall be removed and the flame
of the burner extinguished.
6 Evaluation of test results
After all burning has ceased, the test piece shall be wiped clean.
All soot shall be ignored if, when wiped off, the original surface is undamaged. Softening or any
deformation of the non-metallic materials shall also be ignored. The distance from the lower
edge of the top support to the upper onset of charring and the distance from the lower edge of
the top support to the lower onset of charring shall be measured to the nearest millimetre.
The onset of char shall be determined as follows.
Press against the cable surface with a sharp object, for example, a knife blade. Where the
surface changes from a resilient to a brittle (crumbling) surface, this indicates the onset of
charring.
7 Performance requirements 7
If no performance requirements are given in the relevant cable specification, Annex A shall be
followed.
Dimensions in millimetres
Key
1 metal enclosure
2 support arm and copper wire fixing
3 test piece
Distance A: Length from base of enclosure to bottom of test piece = 50 mm (approximately)
Figure 1 – Arrangement of test piece in test apparatus

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Dimensions in millimetres
45° ±2°
IEC
475 ±5
Key
1 lower edge of top support
2 test piece
3 position of impingement of blue cone
4 optional metal wire loop for securing the position of the test piece in the test flame in case the test piece moves
out of the flame, for example by breaking
Figure 2 – Application of flame to test piece

– 12 – IEC 60332-1-2:2025 CMV © IEC 2025
Annex A
(informativenormative) 8
Recommended Performance requirements
The performance requirements for a particular type or class of insulated conductor or cable
should preferably be given in the individual cable standard. In the absence of any given
requirement it is recommended that those, requirements given below should shall be taken as
a minimum acceptable level. These requirements are also listed in Table A.1.
The single insulated conductor or cable shall pass passes the test if the distance between the
lower edge of the top support and the upper onset of charring is greater than 50 mm.
In addition, a failure shall be is recorded if the lower onset of charring extends downwards to a
point greater than 540 mm from the lower edge of the top support.
Additionally, in order to pass the test, the distance from the upper onset of charring (above the
flame application point) to the lower onset of charring (below the flame application point) is not
in excess of 425 mm. 9
If a failure is recorded, two more tests shall be are carried out. If both tests result in passes,
the single insulated conductor or cable shall be is deemed to have pas
...