ISO/TS 15791-2:2017

TECHNICAL ISO/TS
SPECIFICATION 15791-2
First edition
2017-06
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 15791-2:2017(E)
©
ISO 2017

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ISO/TS 15791-2:2017(E)

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ISO/TS 15791-2:2017(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 . 5
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 . 6
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 . 7
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 15791-2:2017(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 on 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: w w w . i s o .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 4, Burning
behaviour.
A list of all parts in the ISO 15791 series can be found on the ISO website.
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ISO/TS 15791-2:2017(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.
[9]
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 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 15791-2:2017(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 5658-2:2006, 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
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.
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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
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 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
EXAMPLE 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
semi-finished product
manufactured article ready for assembly for an end-use application
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
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— 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
— 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 of a product, then the test can be used for end-product testing.
These tests should reflect the end-use application scenario as far as is 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 measurement of the principal fire parameters (ignitability,
spread of flame, heat release, ignited droplets and smoke).
[8]
NOTE A guide for extended application is found in EN/TS 15117 .
2
Table 1 summarizes which test methods with a test specimen size of less than 1 m can be used and
which measurements are possible.
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Table 1 — Examples of the applicability of intermediate-scale fire tests
Use/requirements Test methods
ISO 9239-1
a
ISO 5658-4 ISO 21367 ISO 14696
ISO 9239-2
Only for flat
Preselection test Yes Yes Yes
products
Only for vertical Only for vertical Only for vertical
product product product
Only for horizontal
End-product test
Adaptation of test Adaptation of test Adaptation of test
flat products
specimen for specimen for specimen for
profiled product profiled product profiled product
Possible presence Possible presence Possible presence Possible presence
Additional parameters
of joints of joints of joints of joints
Requirements for
Yes Yes Yes Yes
ignitability
Requirements for Only lateral spread Lateral and vertical Lateral and vertical Vertical spread of
spread of flame of flame spread of flame spread of flame flame
Requirements for
No Yes Yes Yes
ignited droplets
Requirements for heat
No No Yes Yes
release
Requirements for
Yes No Yes Yes
smoke opacity
Requirements for
b b b b
No No No No
smoke toxicity
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 [5]
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.
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5.2.2 Complex products ready for assembly for an end-use application
Complex 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;
— 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 best 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.
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The substrate required in the end-use condition is used in the test. The method of choice of the substrate
is given by 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.
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.
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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.
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 appearing in end-use shall be a part of the
product tested.
A surface coating attached to a product at the construction site shall be treated and evaluated as
an independent surface coating product but shall be tested with the substrate (whether it is non-
combustible or combustible) to which the coating is applied.
6.2.3 Joints and sealing materials for joints and other arrangements
In order to evaluate the fire performance of joints, a joint used in the end-use application of the product
shall be included in the test specimen. In order to simulate joints between massive mineral elements
(e.g. concrete, masonry), angles of calcium silicate boards (see 6.1.3) shall be used as supporting
construction.
Joints shall be built up in the test specimen according to the specification provided by the manufacturer.
6.2.4 Insulation materials
6.2.4.1 Rigid foams
The method of applying rigid foam insulation shall be in accordance with the relevant product standard.
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