ISO/TS 15791-2:2022
(Main)Plastics — Development and use of intermediate-scale fire tests for plastics products — Part 2: Use of intermediate-scale tests for semi-finished and finished products
Plastics — Development and use of intermediate-scale fire tests for plastics products — Part 2: Use of intermediate-scale tests for semi-finished and finished products
This document provides guidelines and specifies requirements for the development and use of intermediate-scale fire tests applicable to semi-finished and finished products made of, or containing, plastics. This document covers typical applications of such tests, as well as methods of preparation and mounting of test specimens. This document applies to planar, linear or profiled plastics products. These products can be tested in horizontal or vertical orientation. This document defines the parameters to be measured, the way that test results are expected to be reported and explains how they can be used for direct product assessment or as input data for scaling studies.
Plastiques — Développement et utilisation des essais au feu à une échelle intermédiaire pour les produits plastiques — Partie 2: Utilisation des essais à une échelle intermédiaire pour les produits semi-finis et les produits finis
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TECHNICAL ISO/TS
SPECIFICATION 15791-2
Second edition
2022-11
Plastics — Development and use
of intermediate-scale fire tests for
plastics products —
Part 2:
Use of intermediate-scale tests for
semi-finished and finished products
Plastiques — Développement et utilisation des essais au feu à une
échelle intermédiaire pour les produits plastiques —
Partie 2: Utilisation des essais à une échelle intermédiaire pour les
produits semi-finis et les produits finis
Reference number
ISO/TS 15791-2:2022(E)
© ISO 2022
---------------------- Page: 1 ----------------------
ISO/TS 15791-2:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
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ISO/TS 15791-2:2022(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Different applications of intermediate-scale fire tests . 2
4.1 General . 2
4.2 Pre-selection tests on semi-finished products . 3
4.3 End-product tests . 3
5 Types of plastics and typical products . 4
5.1 Generic types . 4
5.2 Typical products . . 4
5.2.1 General . 4
5.2.2 Complex products ready for assembly for an end-use application . 4
5.2.3 Profiled products . 5
6 Method of preparation and mounting of test specimens . 5
6.1 General method of preparation and mounting of test specimens . 5
6.1.1 Finished products . 5
6.1.2 Substrates . 5
6.1.3 Backing boards . 5
6.1.4 Joint . 6
6.1.5 Fixing of test specimens to substrates . 6
6.1.6 Air gap between test specimen and backing board . 6
6.2 Preparation and mounting method for specific types of products . 7
6.2.1 Boards/sheets . 7
6.2.2 Surface coatings . 7
6.2.3 Joints and sealing materials for joints and other arrangements . 7
6.2.4 Insulation materials . 7
6.2.5 Composites . 8
6.2.6 Pipe and pipe insulation . 8
6.2.7 Roof lights and light diffusers . 9
6.2.8 Curtain walling . 9
7 Matters relevant for semi-finished or finished plastic products .9
7.1 Sample conditioning and test specimen preparation . 9
7.2 Practical advice on operating procedures in the event of test specimen collapse or
deformation on exposure to heat from standard ignition sources . . 9
7.3 Problem–solving approaches to complications caused by melting effects in
thermoplastics . 10
7.4 Intumescence . 10
7.5 Slumping of the thermoplastic sheets . 10
7.6 Flaming debris . 10
7.7 Profiled products . 11
Annex A (normative) Preparation and use of test specimens with relevance to product end-
use conditions .12
Bibliography .14
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ISO/TS 15791-2:2022(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 4, Burning
behaviour.
This second edition cancels and replaces the first edition (ISO/TS 15791-2:2017), which has been
technically revised.
The main changes are as follows:
— technical update in Clause 4 has been updated;
— the following references have been added:
— ISO 14697 (as a normative reference);
— ISO/TS 17431 (as an informative reference).
A list of all parts in the ISO 15791 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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ISO/TS 15791-2:2022(E)
Introduction
The major benefit in intermediate-scale testing is the ability to reflect more accurately the fire
conditions of real fires than small-scale tests. For example:
— Specimen mounting. Specimens can incorporate end-use fixings, joints and air-gaps (see Annex A)
in the larger test apparatus. In addition, thick and/or profiled products may be accommodated. This
capability is valuable for testing thick multilayer composites (such as sandwich structures). It is
also useful for testing profiled product such as pipes, pipe insulations, cable trays, GRP frames and
similar products.
— Test specimen size and orientation. Intermediate-scale tests allow to evaluate fire growth. The
ability to measure flame spread beyond the impingement zone of the ignition source is a desirable
feature.
— Observation of actual phenomena of products (especially thermoplastics) exposed to ignition
sources. Representative behaviour may be observed with intermediate-scale test specimens.
[11]
The test results may be useful to the manufacturers of the products and regulation authorities .
However, intermediate-scale tests may have the following disadvantages because of their large scale.
— Intermediate-scale tests may develop an increased amount of fire effluent.
— Intermediate-scale tests may require higher cost.
— An intermediate-scale test may limit the fire scenario and cannot realize a wide range of fire
behaviours.
An intermediate-scale test can be used as a screening test for large-scale tests for the purpose of
research and product development.
In addition to the usage mentioned above, this document has been prepared for manufacturers of
semi-finished plastics products. These semi-finished products may be tested for production control or
developmental reasons. They cannot always be tested in the end-use conditions (such as mounting and
fixing) that are appropriate for finished products.
This document is intended to support the information that product manufacturers may require as part
of a quality assurance scheme. In addition, it should be recognized that this document is not intended
to replace finished product technical specifications for products containing a semi-finished plastics
component.
The information given in this document is in accordance with the principles recommended in ISO 10840,
which was established to develop a general policy and philosophy for the development and use of fire
tests for plastics.
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TECHNICAL SPECIFICATION ISO/TS 15791-2:2022(E)
Plastics — Development and use of intermediate-scale fire
tests for plastics products —
Part 2:
Use of intermediate-scale tests for semi-finished and
finished products
1 Scope
This document provides guidelines and specifies requirements for the development and use of
intermediate-scale fire tests applicable to semi-finished and finished products made of, or containing,
plastics.
This document covers typical applications of such tests, as well as methods of preparation and mounting
of test specimens.
This document applies to planar, linear or profiled plastics products. These products can be tested in
horizontal or vertical orientation.
This document defines the parameters to be measured, the way that test results are expected to be
reported and explains how they can be used for direct product assessment or as input data for scaling
studies.
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.
ISO 834-12, Fire resistance tests — Elements of building construction — Part 12: Specific requirements for
separating elements evaluated on less than full scale furnaces
ISO 10840, Plastics — Guidance for the use of standard fire tests
ISO 13943, Fire safety — Vocabulary
ISO 14697, Reaction-to-fire tests — Guidance on the choice of substrates for building and transport products
ISO 25762, Plastics — Guidance on the assessment of the fire characteristics and fire performance of fibre-
reinforced polymer composites
ISO 30021, Plastics — Burning behaviour — Intermediate-scale fire-resistance testing of fibre-reinforced
polymer composites
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 10840, ISO 13943 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
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ISO/TS 15791-2:2022(E)
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
end-use application
real application of a product including method of installation
3.2
finished product
manufactured article ready for end-use
3.3
intermediate-scale fire test
fire test performed on a test specimen (3.9) of smaller dimensions than the final end-use product/system
3.4
pre-selection test
test which provides data for the process of assessing and choosing candidate materials, components or
subassemblies for making an end-product
3.5
product parameter
aspect of a product which may vary and which may have an influence on the product’s fire performance,
e.g. thickness, composition and density
3.6
profiled product
homogenous product with a non-planar surface
3.7
sample
representative part of a manufactured product or piece of a material or semi-finished product (3.8)
3.8
semi-finished product
manufactured article ready for assembly for an end-use application (3.1)
3.9
test specimen
test piece that may be cut from a sample of a product, or prepared by moulding or otherwise, as specified
by the test procedure, or a representative sample of the product itself
4 Different applications of intermediate-scale fire tests
4.1 General
The intermediate-scale fire test can be used for direct product assessment when a test specimen of a
finished product can be tested in end-use conditions.
Intermediate-scale tests can evaluate several parameters such as ignitability, flame spread, orientation
and the mounting effects of products. These parameters may be used to indicate the behaviour of
products in large-scale or full-scale fire tests.
An intermediate-scale tests may be used
— as a pre-selection test to evaluate the influence of product parameters on the fire behaviour of semi-
finished products and to aid the development process, and/or
— to evaluate, as far as possible, end-use conditions.
The ways in which different types of tests are used are explained in the following subclauses.
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ISO/TS 15791-2:2022(E)
4.2 Pre-selection tests on semi-finished products
An intermediate-scale test can be used as a pre-selection test
— to aid the selection of materials, components and sub-assemblies during the design stage when
small-scale tests are not appropriate because of the complexity of the product, and/or
— to study the influence of product parameters on the fire behaviour of the products.
4.3 End-product tests
If it is possible to reproduce the end-use condition for a product, the test should be conducted in such
condition. The test should reflect the end-use application scenario as far as possible. Important factors
to consider include relevance of configuration, orientation, ventilation and the nature of the ignition
source.
Reaction-to-fire testing for fire safety and for fire hazard assessment of products should be programmed
as follows:
a) define the relevant product-application (or misuse) scenario;
b) specify the fire hazard to be assessed (e.g. vision impairment by smoke) and the required safety
criteria;
c) select the appropriate test method;
d) conduct the tests and analyse the data with respect to the defined criteria;
e) select acceptable or unacceptable for the candidate materials or products.
Intermediate-scale fire test methods permit measurements of the principal fire parameters (ignitability,
spread of flame, heat release, ignited droplets, smoke effluent gases).
NOTE A guide for extended application is found in EN/TS 15117.
Table 1 summarizes which test methods with an intermediate test specimen can be used and which
measurements are possible.
Table 1 — Examples of the applicability of intermediate-scale fire tests
Use/ Test methods
measurements
ISO 9239-1
a
ISO 5658-4 ISO 21367 ISO/TS 17431 ISO 14696
ISO 9239-2
Preselection Only for flat
Yes Yes Yes Yes
test products
Only for vertical Only for vertical Only for flat Only for vertical
product product products product
End-product Only for horizontal
Adaptation of Adaptation of Adaptation of
test flat products
test specimen for test specimen for test specimen for
profiled product profiled product profiled product
Additional pa- Possible presence Possible pres- Possible pres- Possible pres- Possible presence
rameters of joints ence of joints ence of joints ence of joints of joints
a
The standardized size of the test specimen is 1,5 m × 1,0 m. This method could apply on a test specimen with reduced
size (e.g. 1 m × 1 m).
b
Measurement using Fourier transform infrared (FTIR) spectroscopy following the guidance of ISO 19702 is technically
possible, but has not been standardized. Care should be taken concerning the dilution of the fire effluent and the limits of
quantification.
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ISO/TS 15791-2:2022(E)
TTabablele 1 1 ((ccoonnttiinnueuedd))
Use/ Test methods
measurements
ISO 9239-1
a
ISO 5658-4 ISO 21367 ISO/TS 17431 ISO 14696
ISO 9239-2
Ignitability Yes Yes Yes No Yes
Lateral and Lateral and Lateral and
Only lateral spread Vertical spread of
Spread of flame vertical spread of vertical spread of vertical spread of
of flame flame
flame flame flame
Flash-over No No No Yes No
Ignited droplets No Yes Yes No Yes
Heat release No No Yes Yes Yes
Smoke opacity Yes No Yes Yes Yes
b b b b b
Smoke toxicity No No No No No
a
The standardized size of the test specimen is 1,5 m × 1,0 m. This method could apply on a test specimen with reduced
size (e.g. 1 m × 1 m).
b
Measurement using Fourier transform infrared (FTIR) spectroscopy following the guidance of ISO 19702 is technically
possible, but has not been standardized. Care should be taken concerning the dilution of the fire effluent and the limits of
quantification.
5 Types of plastics and typical products
5.1 Generic types
All of the following types of plastics materials or products can be involved in a fire performance
assessment:
— thermoplastics;
— thermosets;
— fibre-reinforced polymer composites;
— honeycomb composites contained plastics;
— sandwich panels contained cellular plastics.
5.2 Typical products
5.2.1 General
Some applications of plastics which present particular problems in small-scale tests for their fire
performance assessment and which may require the use of intermediate-scale fire testing are described
in 5.2.2 and 5.2.3.
5.2.2 Complex products ready for assembly for an end-use application
Composite products ready for assembly for an end-use application may be tested as semi-finished
products. They include:
— boards/sheets with coating and joints;
— insulation materials with surface covering layers;
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ISO/TS 15791-2:2022(E)
— composites:
— laminates, e.g. melamine-formaldehyde-covered chipboard;
— laminated film and sheet, e.g. weatherproofing membranes;
— moulded foams, e.g. for packaging;
— structural mouldings, e.g. for ships, lorries, coaches, trains, aircraft;
— composite panels, e.g. rigid foams faced with metal sheets (especially steel or aluminium sheets)
or inorganics (especially gypsum or plasterboard) for thermal insulation;
— fibre-reinforced products.
5.2.3 Profiled products
Profiled products may be tested as finished products. They include:
— housings for electrical appliances;
— profiled sheets, e.g. roofing or panels for containers;
— profiles, e.g. conduits for electric cables, window-frames, extruded sections;
— weatherproof glazing for agricultural buildings;
— foam pipe-sections;
— pipes, e.g. rainwater drainage and discharge pipes;
— pipes for air ventilation systems in, for example, ships, trains, aircraft;
— containers for liquids, e.g. oil, kerosene;
— waste containers (for recycling materials or for rubbish).
6 Method of preparation and mounting of test specimens
6.1 General method of preparation and mounting of test specimens
6.1.1 Finished products
In tests on a finished product, the preparation and mounting of the test specimen should aim to match
the end-use application as far as practicably possible.
The general principles are specified in Annex A.
6.1.2 Substrates
Products which are self-standing or not applied to any substrate in the end-use condition will not
require a substrate.
The substrate required in the end-use condition is used in the test. The method of choice of the substrate
shall be in accordance with ISO 14697.
6.1.3 Backing boards
Backing boards are required for many tests. For the backing board, alternatives are available:
a) panels of calcium silicate board with thickness and density specified in each test standard, or
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ISO/TS 15791-2:2022(E)
b) for products that are fixed to a substrate identical to the backing board, only one backing board
behind each test specimen is required.
Non-combustible substrates and backing boards can be reused if they are not contaminated with any
residue which may result in significant contribution to the rate of heat release, flame spread, smoke
production or other burning behaviour and if the board is not cracked or in other ways damaged. If
mechanical fixing has left holes with a diameter greater than 3 mm, the board is considered damaged
and cannot be reused.
6.1.4 Joint
If the joint in end-use is covered or sealed, this should also be the case in the test.
6.1.5 Fixing of test specimens to substrates
6.1.5.1 General
Methods of fixing the test specimens to substrates specified in this document shall be used if not
specified in the relevant product standard.
6.1.5.2 Mechanical fixing
The method of mechanical fixing of a test specimen to a substrate should be the same as that used in the
end-use condition as far as is practicable. The following is an alternative recommended method.
Boards which are mechanically fixed to a substrate should be fixed using screws unless otherwise
specified. The number of fixings should be 10 per metre. The fixings should be evenly distributed on the
boards and none of them closer than 25 mm from any edges.
Insulating materials which are mechanically fixed shall be fixed using pins and washers having
sufficient diameter to keep the materials in their end-use position. The number of fixings should be the
same as for boards.
6.1.5.3 Glue
Products that are glued to a substrate shall be glued using the glue and the procedure specified by the
sponsor. If product manufacturers have not specified a glue, the following specification is recommended:
Silica (as SiO ) (30 ± 2) %
2
Total alkali (as Na O) (10 ± 1) %
2
Water (60 ± 3) %
Weight ratio SiO /Na O 3,1 to 3,4/1
2 2
Viscosity at 20 °C 0,65 Pa·s to 1,20 Pa·s
Gluing shall be done according to the end-use conditions. Thus, in some cases, the glue has to be applied
only as dots and not for the whole area.
6.1.6 Air gap between test specimen and backing board
For some products, an air gap between the test specimen and the backing board is required. If the
product is self-supporting, the air gap is made using distance holders at the top and bottom of the test
specimen. Additional distance holders may be required if the test specimen could deform during the
test. If the product is not self-supporting, it should be mounted according to end-use conditions on
request by the supplier.
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ISO/TS 15791-2:2022(E)
6.2 Preparation and mounting method for specific types of products
6.2.1 Boards/sheets
6.2.1.1 General
The test methods which are listed in Table 1 can be used to test these products as pre-selection tests or
end-use tests if the test specimen is prepared or mounted as the following.
6.2.1.2 Free-standing boards with an air gap
Free-standing boards shall be fixed to a frame using appropriate fixings. If the product maintains its
stability during the test and is not fixed in its end-use condition, it may be tested without the frame and
the fixings.
Multi-layered products with an air gap (e.g. polycarbonate) shall be tested with vertical channels. The
openings at the edges shall be closed according to the instructions of the manufacturer.
6.2.2 Surface coatings
If, in practice, the products are equipped with surface coatings in the manufacturing procedure, they
are to be tested together with the surface coating. However, plastic foils for transport protection shall
be removed before conditioning.
If the surfaces of the products are coated/painted only after leaving the factory, representative
coatings/paints shall be applied using the end-use amount/thickness. The representative coating/paint
shall be as similar as practicable to the end-use material. In tests on building boards, a dispersion based
paint can be used to simulate other wall paints.
A surface coating applied in the manufacturing process and a
...
TECHNICAL ISO/TS
SPECIFICATION 15791-2
Second edition
Plastics — Development and use
of intermediate-scale fire tests for
plastics products —
Part 2:
Use of intermediate-scale tests for
semi-finished and finished products
Plastiques — Développement et utilisation des essais au feu à une
échelle intermédiaire pour les produits plastiques —
Partie 2: Utilisation des essais à une échelle intermédiaire pour les
produits semi-finis et les produits finis
PROOF/ÉPREUVE
Reference number
ISO/TS 15791-2:2022(E)
© ISO/TS 2022
---------------------- Page: 1 ----------------------
ISO/TS 15791-2:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
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ISO/TS 15791-2:2022(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Different applications of intermediate-scale fire tests . 2
4.1 General . 2
4.2 Pre-selection tests on semi-finished products . 3
4.3 End-product tests . 3
5 Types of plastics and typical products . 4
5.1 Generic types . 4
5.2 Typical products . . 4
5.2.1 General . 4
5.2.2 Complex products ready for assembly for an end-use application . 4
5.2.3 Profiled products . 5
6 Method of preparation and mounting of test specimens . 5
6.1 General method of preparation and mounting of test specimens . 5
6.1.1 Finished products . 5
6.1.2 Substrates . 5
6.1.3 Backing boards . 5
6.1.4 Joint . 6
6.1.5 Fixing of test specimens to substrates . 6
6.1.6 Air gap between test specimen and backing board . 6
6.2 Preparation and mounting method for specific types of products . 7
6.2.1 Boards/sheets . 7
6.2.2 Surface coatings . 7
6.2.3 Joints and sealing materials for joints and other arrangements . 7
6.2.4 Insulation materials . 7
6.2.5 Composites . 8
6.2.6 Pipe and pipe insulation . 8
6.2.7 Roof lights and light diffusers . 9
6.2.8 Curtain walling . 9
7 Matters relevant for semi-finished or finished plastic products .9
7.1 Sample conditioning and test specimen preparation . 9
7.2 Practical advice on operating procedures in the event of test specimen collapse or
deformation on exposure to heat from standard ignition sources . . 9
7.3 Problem–solving approaches to complications caused by melting effects in
thermoplastics . 10
7.4 Intumescence . 10
7.5 Slumping of the thermoplastic sheets . 10
7.6 Flaming debris . 10
7.7 Profiled products . 11
Annex A (normative) Preparation and use of test specimens with relevance to product end-
use conditions .12
Bibliography .14
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ISO/TS 15791-2:2022(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 4, Burning
behaviour.
This second edition cancels and replaces the first edition (ISO/TS 15791-2:2017), which has been
technically revised.
The main changes are as follows:
— technical update in Clause 4 has been updated;
— the following references have been added:
— ISO 14697 (as a normative reference);
— ISO/TS 17431 (as an informative reference).
A list of all parts in the ISO 15791 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
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ISO/TS 15791-2:2022(E)
Introduction
The major benefit in intermediate-scale testing is the ability to reflect more accurately the fire
conditions of real fires than small-scale tests. For example:
— Specimen mounting. Specimens can incorporate end-use fixings, joints and air-gaps (see Annex A)
in the larger test apparatus. In addition, thick and/or profiled products may be accommodated. This
capability is valuable for testing thick multilayer composites (such as sandwich structures). It is
also useful for testing profiled product such as pipes, pipe insulations, cable trays, GRP frames and
similar products.
— Test specimen size and orientation. Intermediate-scale tests allow to evaluate fire growth. The
ability to measure flame spread beyond the impingement zone of the ignition source is a desirable
feature.
— Observation of actual phenomena of products (especially thermoplastics) exposed to ignition
sources. Representative behaviour may be observed with intermediate-scale test specimens.
[11]
The test results may be useful to the manufacturers of the products and regulation authorities .
However, intermediate-scale tests may have the following disadvantages because of their large scale.
— Intermediate-scale tests may develop an increased amount of fire effluent.
— Intermediate-scale tests may require higher cost.
— An intermediate-scale test may limit the fire scenario and cannot realize a wide range of fire
behaviours.
An intermediate-scale test can be used as a screening test for large-scale tests for the purpose of
research and product development.
In addition to the usage mentioned above, this document has been prepared for manufacturers of
semi-finished plastics products. These semi-finished products may be tested for production control or
developmental reasons. They cannot always be tested in the end-use conditions (such as mounting and
fixing) that are appropriate for finished products.
This document is intended to support the information that product manufacturers may require as part
of a quality assurance scheme. In addition, it should be recognized that this document is not intended
to replace finished product technical specifications for products containing a semi-finished plastics
component.
The information given in this document is in accordance with the principles recommended in ISO 10840,
which was established to develop a general policy and philosophy for the development and use of fire
tests for plastics.
v
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TECHNICAL SPECIFICATION ISO/TS 15791-2:2022(E)
Plastics — Development and use of intermediate-scale fire
tests for plastics products —
Part 2:
Use of intermediate-scale tests for semi-finished and
finished products
1 Scope
This document provides guidelines and specifies requirements for the development and use of
intermediate-scale fire tests applicable to semi-finished and finished products made of, or containing,
plastics.
This document covers typical applications of such tests, as well as methods of preparation and mounting
of test specimens.
This document applies to planar, linear or profiled plastics products. These products can be tested in
horizontal or vertical orientation.
This document defines the parameters to be measured, the way that test results are expected to be
reported and explains how they can be used for direct product assessment or as input data for scaling
studies.
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.
ISO 834-12, Fire resistance tests — Elements of building construction — Part 12: Specific requirements for
separating elements evaluated on less than full scale furnaces
ISO 10840, Plastics — Guidance for the use of standard fire tests
ISO 13943, Fire safety — Vocabulary
ISO 14697, Reaction-to-fire tests — Guidance on the choice of substrates for building and transport products
ISO 25762, Plastics — Guidance on the assessment of the fire characteristics and fire performance of fibre-
reinforced polymer composites
ISO 30021, Plastics — Burning behaviour — Intermediate-scale fire-resistance testing of fibre-reinforced
polymer composites
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 10840, ISO 13943 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
1
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ISO/TS 15791-2:2022(E)
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
end-use application
real application of a product including method of installation
3.2
finished product
manufactured article ready for end-use
3.3
intermediate-scale fire test
fire test performed on a test specimen (3.9) of smaller dimensions than the final end-use product/system
3.4
pre-selection test
test which provides data for the process of assessing and choosing candidate materials, components or
subassemblies for making an end-product
3.5
product parameter
aspect of a product which may vary and which may have an influence on the product’s fire performance,
e.g. thickness, composition and density
3.6
profiled product
homogenous product with a non-planar surface
3.7
sample
representative part of a manufactured product or piece of a material or semi-finished product (3.8)
3.8
semi-finished product
manufactured article ready for assembly for an end-use application (3.1)
3.9
test specimen
test piece that may be cut from a sample of a product, or prepared by moulding or otherwise, as specified
by the test procedure, or a representative sample of the product itself
4 Different applications of intermediate-scale fire tests
4.1 General
The intermediate-scale fire test can be used for direct product assessment when a test specimen of a
finished product can be tested in end-use conditions.
Intermediate-scale tests can evaluate several parameters such as ignitability, flame spread, orientation
and the mounting effects of products. These parameters may be used to indicate the behaviour of
products in large-scale or full-scale fire tests.
An intermediate-scale tests may be used
— as a pre-selection test to evaluate the influence of product parameters on the fire behaviour of semi-
finished products and to aid the development process, and/or
— to evaluate, as far as possible, end-use conditions.
The ways in which different types of tests are used are explained in the following subclauses.
2
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ISO/TS 15791-2:2022(E)
4.2 Pre-selection tests on semi-finished products
An intermediate-scale test can be used as a pre-selection test
— to aid the selection of materials, components and sub-assemblies during the design stage when
small-scale tests are not appropriate because of the complexity of the product, and/or
— to study the influence of product parameters on the fire behaviour of the products.
4.3 End-product tests
If it is possible to reproduce the end-use condition for a product, the test should be conducted in such
condition. The test should reflect the end-use application scenario as far as possible. Important factors
to consider include relevance of configuration, orientation, ventilation and the nature of the ignition
source.
Reaction-to-fire testing for fire safety and for fire hazard assessment of products should be programmed
as follows:
a) define the relevant product-application (or misuse) scenario;
b) specify the fire hazard to be assessed (e.g. vision impairment by smoke) and the required safety
criteria;
c) select the appropriate test method;
d) conduct the tests and analyse the data with respect to the defined criteria;
e) select acceptable or unacceptable for the candidate materials or products.
Intermediate-scale fire test methods permit measurements of the principal fire parameters (ignitability,
spread of flame, heat release, ignited droplets, smoke effluent gases).
NOTE A guide for extended application is found in EN/TS 15117.
Table 1 summarizes which test methods with an intermediate test specimen can be used and which
measurements are possible.
Table 1 — Examples of the applicability of intermediate-scale fire tests
Use/ Test methods
measurements
ISO 9239-1
a
ISO 5658-4 ISO 21367 ISO/TS 17431 ISO 14696
ISO 9239-2
Preselection Only for flat
Yes Yes Yes Yes
test products
Only for vertical Only for vertical Only for flat Only for vertical
product product products product
End-product Only for horizontal
Adaptation of Adaptation of Adaptation of
test flat products
test specimen for test specimen for test specimen for
profiled product profiled product profiled product
Additional pa- Possible presence Possible pres- Possible pres- Possible pres- Possible presence
rameters of joints ence of joints ence of joints ence of joints of joints
a
The standardized size of the test specimen is 1,5 m × 1,0 m. This method could apply on a test specimen with reduced
size (e.g. 1 m × 1 m).
b
Measurement using Fourier transform infrared (FTIR) spectroscopy following the guidance of ISO 19702 is technically
possible, but has not been standardized. Care should be taken concerning the dilution of the fire effluent and the limits of
quantification.
3
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ISO/TS 15791-2:2022(E)
TTabablele 1 1 ((ccoonnttiinnueuedd))
Use/ Test methods
measurements
ISO 9239-1
a
ISO 5658-4 ISO 21367 ISO/TS 17431 ISO 14696
ISO 9239-2
Ignitability Yes Yes Yes No Yes
Lateral and Lateral and Lateral and
Only lateral spread Vertical spread of
Spread of flame vertical spread of vertical spread of vertical spread of
of flame flame
flame flame flame
Flash-over No No No Yes No
Ignited droplets No Yes Yes No Yes
Heat release No No Yes Yes Yes
Smoke opacity Yes No Yes Yes Yes
b b b b b
Smoke toxicity No No No No No
a
The standardized size of the test specimen is 1,5 m × 1,0 m. This method could apply on a test specimen with reduced
size (e.g. 1 m × 1 m).
b
Measurement using Fourier transform infrared (FTIR) spectroscopy following the guidance of ISO 19702 is technically
possible, but has not been standardized. Care should be taken concerning the dilution of the fire effluent and the limits of
quantification.
5 Types of plastics and typical products
5.1 Generic types
All of the following types of plastics materials or products can be involved in a fire performance
assessment:
— thermoplastics;
— thermosets;
— fibre-reinforced polymer composites;
— honeycomb composites contained plastics;
— sandwich panels contained cellular plastics.
5.2 Typical products
5.2.1 General
Some applications of plastics which present particular problems in small-scale tests for their fire
performance assessment and which may require the use of intermediate-scale fire testing are described
in 5.2.2 and 5.2.3.
5.2.2 Complex products ready for assembly for an end-use application
Composite products ready for assembly for an end-use application may be tested as semi-finished
products. They include:
— boards/sheets with coating and joints;
— insulation materials with surface covering layers;
4
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ISO/TS 15791-2:2022(E)
— composites:
— laminates, e.g. melamine-formaldehyde-covered chipboard;
— laminated film and sheet, e.g. weatherproofing membranes;
— moulded foams, e.g. for packaging;
— structural mouldings, e.g. for ships, lorries, coaches, trains, aircraft;
— composite panels, e.g. rigid foams faced with metal sheets (especially steel or aluminium sheets)
or inorganics (especially gypsum or plasterboard) for thermal insulation;
— fibre-reinforced products.
5.2.3 Profiled products
Profiled products may be tested as finished products. They include:
— housings for electrical appliances;
— profiled sheets, e.g. roofing or panels for containers;
— profiles, e.g. conduits for electric cables, window-frames, extruded sections;
— weatherproof glazing for agricultural buildings;
— foam pipe-sections;
— pipes, e.g. rainwater drainage and discharge pipes;
— pipes for air ventilation systems in, for example, ships, trains, aircraft;
— containers for liquids, e.g. oil, kerosene;
— waste containers (for recycling materials or for rubbish).
6 Method of preparation and mounting of test specimens
6.1 General method of preparation and mounting of test specimens
6.1.1 Finished products
In tests on a finished product, the preparation and mounting of the test specimen should aim to match
the end-use application as far as practicably possible.
The general principles are specified in Annex A.
6.1.2 Substrates
Products which are self-standing or not applied to any substrate in the end-use condition will not
require a substrate.
The substrate required in the end-use condition is used in the test. The method of choice of the substrate
shall be in accordance with ISO 14697.
6.1.3 Backing boards
Backing boards are required for many tests. For the backing board, alternatives are available:
a) panels of calcium silicate board with thickness and density specified in each test standard, or
5
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ISO/TS 15791-2:2022(E)
b) for products that are fixed to a substrate identical to the backing board, only one backing board
behind each test specimen is required.
Non-combustible substrates and backing boards can be reused if they are not contaminated with any
residue which may result in significant contribution to the rate of heat release, flame spread, smoke
production or other burning behaviour and if the board is not cracked or in other ways damaged. If
mechanical fixing has left holes with a diameter greater than 3 mm, the board is considered damaged
and cannot be reused.
6.1.4 Joint
If the joint in end-use is covered or sealed, this should also be the case in the test.
6.1.5 Fixing of test specimens to substrates
6.1.5.1 General
Methods of fixing the test specimens to substrates specified in this document shall be used if not
specified in the relevant product standard.
6.1.5.2 Mechanical fixing
The method of mechanical fixing of a test specimen to a substrate should be the same as that used in the
end-use condition as far as is practicable. The following is an alternative recommended method.
Boards which are mechanically fixed to a substrate should be fixed using screws unless otherwise
specified. The number of fixings should be 10 per metre. The fixings should be evenly distributed on the
boards and none of them closer than 25 mm from any edges.
Insulating materials which are mechanically fixed shall be fixed using pins and washers having
sufficient diameter to keep the materials in their end-use position. The number of fixings should be the
same as for boards.
6.1.5.3 Glue
Products that are glued to a substrate shall be glued using the glue and the procedure specified by the
sponsor. If product manufacturers have not specified a glue, the following specification is recommended:
Silica (as SiO ) (30 ± 2) %
2
Total alkali (as Na O) (10 ± 1) %
2
Water (60 ± 3) %
Weight ratio SiO /Na O 3,1 to 3,4/1
2 2
Viscosity at 20 °C 0,65 Pa·s to 1,20 Pa·s
Gluing shall be done according to the end-use conditions. Thus, in some cases, the glue has to be applied
only as dots and not for the whole area.
6.1.6 Air gap between test specimen and backing board
For some products, an air gap between the test specimen and the backing board is required. If the
product is self-supporting, the air gap is made using distance holders at the top and bottom of the test
specimen. Additional distance holders may be required if the test specimen could deform during the
test. If the product is not self-supporting, it should be mounted according to end-use conditions on
request by the supplier.
6
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ISO/TS 15791-2:2022(E)
6.2 Preparation and mounting method for specific types of products
6.2.1 Boards/sheets
6.2.1.1 General
The test methods which are listed in Table 1 can be used to test these products as pre-selection tests or
end-use tests if the test specimen is prepared or mounted as the following.
6.2.1.2 Free-standing boards with an air gap
Free-standing boards shall be fixed to a frame using appropriate fixings. If the product maintains its
stability during the test and is not fixed in its end-use condition, it may be tested without the frame and
the fixings.
Multi-layered products with an air gap (e.g. polycarbonate) shall be tested with vertical channels. The
openings at the edges shall be closed according to the instructions of the manufacturer.
6.2.2 Surface coatings
If, in practice, the products are equipped with surface coatings in the manufacturing procedure, they
are to be tested together with the surface coating. However, plastic foils for transport protection shall
be removed before conditioning.
If the surfaces of the products are coated/painted only after leaving the factory, representative
coatings/paints shall be applied using the end-use amount/thickness. The representative coating/paint
shall be as similar as practicable to the end-use material. In tests on buildin
...
ISO/TC 61/SC 4
Date: 2022-0709-12
ISO/PRF TS 15791-2:2022(E)
ISO/TC 61/SC 4
ISO/TC 61/SC 4
Secretariat: BSIBSI
Plastics — Development and use of intermediate-scale fire tests for plastics products —
Part 2: Use of intermediate-scale tests for semi-finished and finished products
Plastiques --— Développement et utilisation des essais au feu à une échelle intermédiaire pour les
produits plastiques --— Partie 2: Utilisation des essais à une échelle intermédiaire pour les
produits semi-finis et les produits finis
For Publication
i © ISO 2015 – All rights reserved
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ISO/PRF TS 15791-2:2022 (E)
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part
of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or
mechanical, including photocopying, or posting on the internet or an intranet, without prior written
permission. Permission can be requested from either ISO at the address below or ISO’s member body
in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.orgwww.iso.org
Published in Switzerland
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ISO/PRF TS 15791-2:2022(E)
Contents Page
Foreword . viv
Introduction . vivi
1 Scope . 11
2 Normative references . 11
3 Terms and definitions . 2 Field Code Changed
Field Code Changed
4 Different applications of intermediate-scale fire tests . 3
4.1 General . 3
Field Code Changed
4.2 Pre-selection tests on semi-finished products . 3
Field Code Changed
4.3 End-product tests . 3
Field Code Changed
5 Types of plastics and typical products . 55
5.1 Generic types . 55
5.2 Typical products . 55
5.2.1 General . 55
5.2.2 Complex products ready for assembly for an end-use application . 55
5.2.3 Profiled products . 55
6 Method of preparation and mounting of test specimens . 66
6.1 General method of preparation and mounting of test specimens . 66
6.1.1 Finished products . 66
6.1.2 Substrates . 66
6.1.3 Backing boards . 66
6.1.4 Joint . 66
6.1.5 Fixing of test specimens to substrates . 77
6.1.6 Air gap between test specimen and backing board . 77
6.2 Preparation and mounting method for specific types of products . 77
6.2.1 Boards/sheets . 77
6.2.2 Surface coatings . 88
6.2.3 Joints and sealing materials for joints and other arrangements . 88
6.2.4 Insulation materials . 88
6.2.5 Composites . 99
6.2.6 Pipe and pipe insulation . 9 Field Code Changed
6.2.7 Roof lights and light diffusers . 9
Field Code Changed
6.2.8 Curtain walling . 9
Field Code Changed
7 Matters relevant for semi-finished or finished plastic products . 10 Field Code Changed
7.1 Sample conditioning and test specimen preparation . 1010
7.2 Practical advice on operating procedures in the event of test specimen collapse or
deformation on exposure to heat from standard ignition sources . 10 Field Code Changed
7.3 Problem–solving approaches to complications caused by melting effects in
thermoplastics . 11 Field Code Changed
7.4 Intumescence . 11
Field Code Changed
7.5 Slumping of the thermoplastic sheets . 1111
7.6 Flaming debris . 11 Field Code Changed
7.7 Profiled products . 11
Field Code Changed
Annex A (normative) Preparation and use of test specimens with relevance to product end-
Field Code Changed
use conditions . 12
A.1 General . 12
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ISO/PRF TS 15791-2:2022 (E)
A.2 Mounting of the test specimen . 12
A.3 Treatment of underlying surface . 12
A.4 Exposed surface to be tested . 12
A.5 Parameters and conditions to be considered . 13
Bibliography . 1414
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ISO/PRF TS 15791-2:2022(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO
collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives 2 (see
www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any
patent rights identified during the development of the document will be in the Introduction and/or on
the ISO list of patent declarations received (see www.iso.org/patentswww.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation onof the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the World
Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL:
www.iso.org/iso/foreword.html), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 4, Burning
behaviour.
This second edition cancels and replaces the first edition (ISO0TSISO/TS 15791-2:2017), which has been
technically revised.
The main changes compared to the previous edition are as follows:
— technical update in clause Clause 4 has been updated;
— addition of established — the following references have been added:
— ISO standard (ISO 14697 and ISO/TS 17431) (as a normative reference);
— ISO/TS 17431 (as an informative reference).
A list of all parts in the ISO 15791 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at
www.iso.org/members.htmlwww.iso.org/members.html.
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ISO/PRF TS 15791-2:2022 (E)
Introduction
The major benefit in intermediate-scale testing is the ability to reflect more accurately the fire conditions
of real fires than small-scale tests. For example:
— Specimen mounting. Specimens can incorporate end-use fixings, joints and air-gaps (see Annex A) in
the larger test apparatus. In addition, thick and/or profiled products may be accommodated. This
capability is valuable for testing thick multilayer composites (such as sandwich structures). It is also
useful for testing profiled product such as pipes, pipe insulations, cable trays, GRP frames and similar
products.
— Test specimen size and orientation. Intermediate-scale tests allow to evaluate fire growth. The ability
to measure flame spread beyond the impingement zone of the ignition source is a desirable feature.
— Observation of actual phenomena of products (especially thermoplastics) exposed to ignition
sources. Representative behaviour may be observed with intermediate-scale test specimens.
[1011]
The test results may be useful to the manufacturers of the products and regulation authorities .
However, intermediate-scale tests may have the following disadvantages because of their large scale.
— Intermediate-scale tests may develop an increased amount of fire effluent.
— Intermediate-scale tests may require higher cost.
— An intermediate-scale test may limit the fire scenario and cannot realize a wide range of fire
behaviours.
An intermediate-scale test can be used as a screening test for large-scale tests for the purpose of research
and product development.
In addition to the usage mentioned above, this document has been prepared for manufacturers of semi-
finished plastics products. These semi-finished products may be tested for production control or
developmental reasons. They cannot always be tested in the end-use conditions (such as mounting and
fixing) that are appropriate for finished products.
This document is intended to support the information that product manufacturers may require as part of
a quality assurance scheme. In addition, it should be recognized that this document is not intended to
replace finished product technical specifications for products containing a semi-finished plastics
component.
The information given in this document is in accordance with the principles recommended in ISO 10840
that, which was established to develop a general policy and philosophy for the development and use of
fire tests for plastics.
vi © ISO 2017 – All rights reserved© ISO 2022 – All rights
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TECHNICAL SPECIFICATION ISO/PRF TS 15791-2:2022(E)
Plastics — Development and use of intermediate-scale fire tests
for plastics products — Part 2: Use of intermediate-scale tests for
semi-finished and finished products
1 Scope
This document provides guidelines and specifies requirements for the development and use of
intermediate-scale fire tests applicable to semi-finished and finished products made of, or containing,
plastics.
This document covers typical applications of such tests, as well as methods of preparation and mounting
of test specimens.
This document applies to planar, linear or profiled plastics products. These products can be tested in
horizontal or vertical orientation.
This document defines the parameters to be measured, the way that test results are expected to be
reported and explains how they can be used for direct product assessment or as input data for scaling
studies.
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.
ISO 834-12, Fire resistance tests — Elements of building construction — Part 12: Specific requirements
for separating elements evaluated on less than full scale furnaces
ISO 5658-2, Reaction to fire tests — Spread of flame — Part 2: Lateral spread on building and transport
products in vertical configuration
ISO 10840, Plastics — Guidance for the use of standard fire tests
ISO 13943, Fire safety — Vocabulary
ISO 14697, Reaction-to-fire tests — Guidance on the choice of substrates for building and transport
products
ISO 25762, Plastics — Guidance on the assessment of the fire characteristics and fire performance of fibre-
reinforced polymer composites
ISO 30021, Plastics — Burning behaviour — Intermediate-scale fire-resistance testing of fibre-reinforced
polymer composites
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ISO/PRF TS 15791-2:2022 (E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 10840 and, ISO 13943 and the
following apply.
ISO and IEC maintain terminologicalterminology 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/obphttps://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1
end-use application
real application of a product including method of installation
3.2
finished product
manufactured article ready for end-use
3.3
intermediate-scale fire test
fire test performed on a test specimen (3.9) of smaller dimensions than the final end-use product/system
3.4
pre-selection test
test which provides data for the process of assessing and choosing candidate materials, components or
subassemblies for making an end-product
3.5
product parameter
aspect of a product which may vary and which may have an influence on the product’s fire performance,
e.g. thickness, composition and density
3.6
profiled product
homogenous product with a non-planar surface
3.7
sample
representative part of a manufactured product or piece of a material or semi-finished product (3.8)
3.8
semi-finished product
manufactured article ready for assembly for an end-use application (3.1)
3.9
test specimen
test piece that may be cut from a sample of a product, or prepared by moulding or otherwise, as specified
by the test procedure, or a representative sample of the product itself
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ISO/PRF TS 15791-2:2022(E)
4 Different applications of intermediate-scale fire tests
4.1 General
The intermediate-scale fire test can be used for direct product assessment when a test specimen of a
finished product can be tested in end-use conditions.
Intermediate-scale tests can evaluate several parameters such as ignitability, flame spread, orientation
and the mounting effects of products. These parameters may be used to indicate the behaviour of
products in large-scale or full-scale fire tests.
An intermediate-scale tests may be used
— as a pre-selection test to evaluate the influence of product parameters on the fire behaviour of semi-
finished products and to aid the development process, and/or
— to evaluate, as far as possible, end-use conditions.
The ways in which different types of tests are used are explained in the following subclauses.
4.2 Pre-selection tests on semi-finished products
An intermediate-scale test can be used as a pre-selection test
— to aid the selection of materials, components and sub-assemblies during the design stage when small-
scale tests are not appropriate because of the complexity of the product, and/or
— to study the influence of product parameters on the fire behaviour of the products.
4.3 End-product tests
If it is possible to reproduce the end-use condition for a product, the test should be conducted in such
condition. The test should reflect the end-use application scenario as far as possible. Important factors to
consider include relevance of configuration, orientation, ventilation and the nature of the ignition source.
Reaction-to-fire testing for fire safety and for fire hazard assessment of products should be programmed
as follows:
a) define the relevant product-application (or misuse) scenario;
b) specify the fire hazard to be assessed (e.g. vision impairment by smoke) and the required safety
criteria;
c) select the appropriate test method;
d) conduct the tests and analyse the data with respect to the defined criteria;
e) select acceptable or unacceptable for the candidate materials or products.
Intermediate-scale fire test methods permit measurements of the principal fire parameters (ignitability,
spread of flame, heat release, ignited droplets, smoke effluent gases).
NOTE A guide for extended application is found in EN/TS 15117.
Table 1 summarizes which test methods with an intermediate test specimen can be used and which
measurements are possible.
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Table 1 — Examples of the applicability of intermediate-scale fire tests
Use/ Test methods
measurement
s
ISO 9239-1
a
ISO 5658-4 ISO 21367 ISO/TS 17431 ISO 14696
ISO 9239-2
Preselection Only for flat
Yes Yes Yes Yes
test products
Only for vertical Only for vertical Only for flat
product product products Only for vertical product
Only for
End-product
Adaptation of Adaptation of Adaptation of test
horizontal flat
test
test specimen test specimen specimen for
products
for for profiled product
profiled product profiled product
Possible Possible Possible
Additional Possible presence Possible presence of
presence of presence of presence of
parameters of joints joints
joints joints joints
Ignitability Yes Yes Yes No Yes
Lateral and Lateral and Lateral and
Spread of Only lateral
vertical spread vertical spread vertical spread Vertical spread of flame
flame spread of flame
of flame of flame of flame
Flash-over No No No Yes No
Ignited
No Yes Yes No Yes
droplets
Heat release No No Yes Yes Yes
Smoke opacity Yes No Yes Yes Yes
b b b b b
Smoke toxicity No No No No No
a
The standardized size of the test specimen is 1,5 m × 1,0 m. This method could apply on a test specimen with reduced
Deleted Cells
size (e.g. 1 m × 1 m).
b
Measurement using Fourier transform infrared (FTIR) spectroscopy following the guidance of ISO 19702 is technically
possible, but has not been standardized. Care should be taken concerning the dilution of the fire effluent and the limits of
quantification.
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ISO/PRF TS 15791-2:2022(E)
5 Types of plastics and typical products
5.1 Generic types
All of the following types of plastics materials or products can be involved in a fire performance
assessment:
— thermoplastics;
— thermosets;
— fibre-reinforced polymer composites;
— honeycomb composites contained plastics;
— sandwich panels contained cellular plastics.
5.2 Typical products
5.2.1 General
Some applications of plastics which present particular problems in small-scale tests for their fire
performance assessment and which may require the use of intermediate-scale fire testing are described
in 5.2.2 and 5.2.3.
5.2.2 Complex products ready for assembly for an end-use application
Composite products ready for assembly for an end-use application may be tested as semi-finished
products. They include:
— boards/sheets with coating and joints;
— insulation materials with surface covering layers;
— composites:
— laminates, e.g. melamine-formaldehyde-covered chipboard;
— laminated film and sheet, e.g. weatherproofing membranes;
— moulded foams, e.g. for packaging;
— structural mouldings, e.g. for ships, lorries, coaches, trains, aircraft;
— composite panels, e.g. rigid foams faced with metal sheets (especially steel or aluminium sheets)
or inorganics (especially gypsum or plasterboard) for thermal insulation;
— fibre-reinforced products.
5.2.3 Profiled products
Profiled products may be tested as finished products. They include:
— housings for electrical appliances;
— profiled sheets, e.g. roofing or panels for containers;
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ISO/PRF TS 15791-2:2022 (E)
— profiles, e.g. conduits for electric cables, window-frames, extruded sections;
— weatherproof glazing for agricultural buildings;
— foam pipe-sections;
— pipes, e.g. rainwater drainage and discharge pipes;
— pipes for air ventilation systems in, for example, ships, trains, aircraft;
— containers for liquids, e.g. oil, kerosene;
— waste containers (for recycling materials or for rubbish).
6 Method of preparation and mounting of test specimens
6.1 General method of preparation and mounting of test specimens
6.1.1 Finished products
In tests on a finished product, the preparation and mounting of the test specimen should aim to match
the end-use application as far as practicably possible.
The general principles are specified in Annex A.
6.1.2 Substrates
Products which are self-standing or not applied to any substrate in the end-use condition will not require
a substrate.
The substrate required in the end-use condition is used in the test. The method of choice of the substrate
is given byshall be in accordance with ISO 14697.
6.1.3 Backing boards
Backing boards are required for many tests. For the backing board, alternatives are available:
a) panels of calcium silicate board with thickness and density specified in each test standard, or
b) for products that are fixed to a substrate identical to the backing board, only one backing board
behind each test specimen is required.
Non-combustible substrates and backing boards can be reused if they are not contaminated with any
residue which may result in significant contribution to the rate of heat release, flame spread, smoke
production or other burning behaviour and if the board is not cracked or in other ways damaged. If
mechanical fixing has left holes with a diameter greater than 3 mm, the board is considered damaged and
cannot be reused.
6.1.4 Joint
If the joint in end-use is covered or sealed, this should also be the case in the test.
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6.1.5 Fixing of test specimens to substrates
6.1.5.1 General
Methods of fixing the test specimens to substrates specified in this document shall be used if not specified
in the relevant product standard.
6.1.5.2 Mechanical fixing
The method of mechanical fixing of a test specimen to a substrate should be the same as that used in the
end-use condition as far as is practicable. The following is an alternative recommended method.
Boards which are mechanically fixed to a substrate should be fixed using screws unless otherwise
specified. The number of fixings should be 10 per metre. The fixings should be evenly distributed on the
boards and none of them closer than 25 mm from any edges.
Insulating materials which are mechanically fixed shall be fixed using pins and washers having sufficient
diameter to keep the materials in their end-use position. The number of fixings should be the same as for
boards.
6.1.5.3 Glue
Products that are glued to a substrate shall be glued using the glue and the procedure specified by the
sponsor. If product manufacturers have not specified a glue, the following specification is recommended:
Silica (as SiO ) (30 ± 2) %
2
Total alkali (as Na O) (10 ± 1) %
2
Water (60 ± 3) %
Weight ratio SiO /Na O 3,1 to 3,4/1
2 2
Viscosity at 20 °C 0,65 Pa·s to 1,20 Pa·s
Gluing shall be done according to the end-use conditions. Thus, in some cases, the glue has to be applied
only as dots and not for the whole area.
6.1.6 Air gap between test specimen and backing board
For some products, an air gap between the test specimen and the backing board is required. If the product
is self-supporting, the air gap is made using distance holders at the top and bottom of the test specimen.
Additional distance holders may be required if the test specimen could deform during the test. If the
product is not self-supporting, it should be mounted according to end-use conditions on request by the
supplier.
6.2 Preparation and mounting method for specific types of products
6.2.1 Boards/sheets
6.2.1.1 General
The test methods which are listed in Table 1 can be used to test these products as pre-selection tests or
end-use tests if the test specimen is prepared or mounted as the following.
6.2.1.2 Free-standing boards with an air gap
Free-standing boards shall be fixed to a frame using appropriate fixings. If the product maintains its
stability during the test and is not fixed in its end-use condition, it may be tested without the frame and
the fixings.
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Multi-layered products with an air gap (e.g. polycarbonate) shall be tested with vertical channels. The
openings at the edges shall be closed according to the instructions o
...
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