ISO/TR 10093:2017

TECHNICAL ISO/TR
REPORT 10093
First edition
2017-11
Plastics — Fire tests — Standard
ignition sources
Plastiques — Essais au feu — Sources d'allumage normalisées
Reference number
ISO/TR 10093:2017(E)
©
ISO 2017

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ISO/TR 10093:2017(E)

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ISO/TR 10093:2017(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Ignition processes . 3
5 Characteristics of ignition sources . 4
6 General principles . 4
6.1 Flaming ignition sources . 4
6.1.1 Diffusion flame ignition source . 4
6.1.2 Premixed flame source . 4
6.2 Issues associated with flaming ignition sources . 4
6.3 Non-flaming ignition sources . 5
7 Smouldering (cigarette) ignition sources . 6
7.1 Traditional cigarettes . 6
7.2 Non-reduced ignition propensity cigarettes . 7
8 Non-flaming electrical ignition sources . 7
8.1 Glow-wire ignition . 7
8.2 Hot-wire ignition . 9
9 Radiant ignition sources .10
9.1 Conical radiant ignition sources .10
9.1.1 General.10
9.1.2 Cone calorimeter ignition source .10
9.1.3 Smoke chamber conical heater .13
9.1.4 Periodic flaming ignition test .16
9.2 Other radiant ignition sources .17
9.2.1 Glowbars ignition source .17
9.2.2 Lateral ignition and flame spread test (LIFT) radiant panel heater. .18
9.2.3 Setchkin ignition .18
10 Infrared heating system .21
11 Diffusion flame ignition .21
11.1 Needle flame ignition .21
11.2 Burning match .22
11.3 Burners generating 50 W or 500 W flames .24
12 Premixed burners .27
12.1 Premixed burner for 1 kW flame .27
12.2 Burners for vertical cable tray tests.28
12.2.1 Venturi burners for 20 kW vertical cable tray tests .28
12.2.2 Burner for vertical riser cable tests .30
12.3 Burner for large scale horizontal tests .30
12.4 Burners for room corner tests .31
12.4.1 Burner for ISO 9705-1.31
12.4.2 Alternate burner for room corner test .32
12.5 Burners for individual product heat release tests .33
12.5.1 Burner for single fuel package calorimeter .33
12.5.2 Square tube propane burner .33
12.5.3 T-shaped propane burner .34
12.5.4 Dual T-shaped propane burner .34
13 Other ignition sources .35
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ISO/TR 10093:2017(E)

13.1 Wood cribs .35
13.2 Paper bags .35
Bibliography .37
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ISO/TR 10093:2017(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: www.iso.org/iso/foreword.html.
The committee responsible for this document is Technical Committee ISO/TC 61, Plastics, Subcommittee
SC 4, Burning behaviour.
This first edition of ISO/TR 10093 cancels and replaces ISO 10093:1998, which has been technically
revised.
The main changes compared to the previous edition are as follows:
— the document has been updated and converted from an International Standard to a Technical Report;
— several additional ignition sources have been added, including some that originate in standards that
have not been issued by ISO or IEC;
— no details of wood crib and paper bag ignition sources are included;
— Annex A and Annex B have been deleted;
— the information that used to be in Annex A on confirmatory procedure for evaluating test flames is
described in IEC 60695-11 and in ASTM D5207;
— the bibliography formerly contained in Annex B has been extended.
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Introduction
Fires are caused by a wide range of possible ignition sources. Statistical analysis of fires has identified
the main primary and secondary sources, especially for fires in buildings. The most frequent sources of
fires have been found to be as follows:
a) cooking appliances;
b) space-heating appliances;
c) electric wiring, connectors and terminations;
d) other electrical appliances (such as washing machines, bedwarmers, televisions, water heaters);
e) cigarettes;
f) matches and smokers' gas lighters;
g) blow-lamps, blow-torches and welding torches;
h) rubbish burning; and
i) candles.
The above list covers the major primary ignition sources for accidental fires. Other sources can be
involved in fires raised maliciously. Research into causes of fires has shown that primary ignition
sources (e.g. glowing cigarettes or dropped flaming matches) can set fire to waste paper, which then
acts as a secondary ignition source of greater intensity.
When analysing and evaluating the various ignition sources for applications involving plastics
materials, it is important to answer the following questions on the basis of detailed fire statistics.
1) What is the significance of the individual ignition sources in various fire risk situations?
2) What proportion is attributable to secondary ignition sources?
3) Where does particular attention have to be paid to secondary ignition sources?
4) To what extent are different ignition sources responsible for fatal fire accidents?
The following laboratory ignition sources are intended to simulate actual ignition sources that have
been shown to be the cause of real fires involving plastics. Laboratory ignition sources are preferred
over actual ignition sources due to their consistency, which results in greater data repeatability within
a laboratory and greater reproducibility between laboratories.
These laboratory ignition sources can be used to develop new test procedures.
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TECHNICAL REPORT ISO/TR 10093:2017(E)
Plastics — Fire tests — Standard ignition sources
1 Scope
This document describes and classifies a range of laboratory ignition sources for use in fire tests on
plastics and products consisting substantially of plastics. These sources vary in intensity and area
of impingement. They are suitable for use to simulate the initial thermal abuse to which plastics are
potentially exposed in certain actual fire risk scenarios.
Different standards developing organizations have issued many standard test methods, specifications
and regulations to assess fire properties of plastics or of products containing plastic materials. Many
of those standards contain ignition sources associated with flaming and non-flaming ignition. This
document describes the ignition sources and references the associated standard.
This compilation of ignition sources does not discuss the application of the standard where the ignition
source is described and is likely not to be a fully comprehensive list of ignition sources.
This document does not address detailed test procedures.
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 13943, Fire safety — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 13943 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
afterflame
persistence of flaming of a material after the ignition source has been removed
3.2
afterflame time
duration of flame
length of time for which a material continues to flame, under specified test conditions, after the ignition
source has been removed
3.3
afterglow
persistence of glowing of a material after cessation of flaming or, if no flaming occurs, after the ignition
source has been removed
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3.4
afterglow time
length of time for which a material continues to glow, under specified test conditions, after the ignition
source has been removed and/or cessation of flaming
3.5
combustion
exothermic reaction of a substance with an oxidizer, generally accompanied by flames and/or glowing
and/or emission of smoke
3.6
ease of ignition
ease with which a material can be ignited under specified test conditions
3.7
exposed surface
surface subjected to the heating conditions of the test
3.8
flame
rapid, self-sustaining, sub-sonic propagation of combustion (3.5) in a gaseous medium, usually with
emission of light
3.9
flame
to produce flame (3.8)
3.10
flaming debris
material separating from the specimen during the test procedure and falling below the initial lower
edge of the specimen and continuing to flame (3.9) as it falls
3.11
glowing combustion
combustion (3.5) of a material in the solid phase without flame (3.8) but with emission of light from the
combustion zone
3.12
ignitability
measure of the ease with which a specimen can be ignited (3.13) due to the influence of an external heat
source under specified test conditions
3.13
ignite, transitive verb
initiate combustion (3.5)
3.14
ignite, intransitive verb
catch fire with or without the application of an external heat source
3.15
ignition
initiation of combustion (3.5)
3.16
ignition source
applied source of heat which is used to ignite (3.13) combustible materials or products
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3.17
ignition temperature
minimum temperature of a material at which sustained combustion (3.5) can be initiated under
specified test conditions
3.18
irradiance
ratio of the radiant flux incident on a small but measurable element of surface containing the point, by
the area of that element
3.19
minimum ignition time
minimum time of exposure of a material to an ignition source (3.16) to obtain sustained combustion
(3.5) under specified test conditions
3.20
primary ignition source
first applied ignition source (3.16)
3.21
punking
propagation of a smouldering combustion (3.5) front after removal of the ignition source (3.16)
3.22
secondary ignition source
heat source which is activated following ignition (3.15) from a primary source
3.23
sustained flaming
flame (3.8), on or over the surface of a test specimen, which persists for longer than a defined
period of time
3.24
transitory flaming
flame (3.8), on or over the surface of a test specimen, which persists for a defined short period of time
Note 1 to entry: Compare with the term sustained flaming (3.23).
4 Ignition processes
4.1 When plastics are exposed to thermal energy, flammable vapours are often generated from
their surface. Under suitable conditions (especially high temperatures), it is possible that a critical
concentration of flammable vapour will form and spontaneous ignition will result. If a flame is present
as the sole energy source, or as a supplementary source, the ignition process will be assisted; this
mechanism is sometimes known as piloted ignition.
4.2 A specimen of plastic is regarded as ignited when flames appear on the surface of the plastic or
when glowing combustion is evident.
4.3 After ignition has occurred, some burning plastics create additional fire hazards by forming flaming
debris or drips. If this flaming debris falls on to combustible material, it is possible that secondary
ignition will occur and the fire will spread more rapidly.
4.4 The localized application of a heat source to some plastics results in glowing combustion. With
some thermoplastic foams and foams from thermosetting materials, the localized application of a heat
source results in punking which produces a carbonaceous char.
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5 Characteristics of ignition sources
5.1 The following factors are the main characteristics describing ignition sources and their relation to
the test specimen:
a) intensity of the ignition source, which is a measure of the thermal load on the specimen resulting
from the combined conduction, convection and radiation effects caused by the ignition source;
b) area of impingement of the ignition source on the specimen;
c) duration of exposure of the specimen and whether it is continuous or intermittent;
d) presentation of the ignition source to the specimen and whether or not it impinges;
e) orientation of the specimen in relation to the ignition source;
f) ventilation conditions in the vicinity of the ignition source and exposed surface of the specimen;
NOTE Factors c) to f) are often a function of the specific fire test conditions.
5.2 Several of the ignition sources provide a range of intensities and areas of impingement to be
considered for use in fire tests of plastics.
6 General principles
6.1 Flaming ignition sources
6.1.1 Diffusion flame ignition source
To form a diffusion flame ignition source, a gas (usually propane, methane or butane) flows through
metallic tubes without ingress of air prior to the base of the flame. These flames simulate natural flames
well but they often fluctuate and are not convenient to direct if any angular presentation is required
towards the specimen.
6.1.2 Premixed flame source
To form a premixed flame source, a gas burner (usually using propane, methane or butane) fitted with
air inlet ports or an air intake manifold is used. Premixed flame sources are typically more directional
than diffusion flame sources and are generally hotter than diffusion flame sources.
6.2 Issues associated with flaming ignition sources
Gas burners are always set up to conform to precise gas flow rates and/or flame heights. Periodic
checks of flame temperature or heat flux precede the setup, but criteria on these parameters are not
necessarily an essential part of the laboratory procedure. After setting up the burner for a particular
test (i.e. often at an acute angle to the test specimen), it is desirable to leave the burner in this orientation
throughout a series of experiments. This objective is conveniently satisfied if the operator only has to
maintain the gas flow constant to the burner.
The gas burners are connected to the gas supply by flexible tubing via a cylinder regulator providing an
outlet pressure, on-off valve, fine-control valve and flowmeter.
Difficulties sometimes occur with the supply and measurement of butane or propane when the cylinders
have been stored in an environment cooler than the defined test conditions and/or some distance
from the test rig. When difficulties occur, a sufficient length of tubing is used inside the controlled
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environment (15 °C to 30 °C) to ensure that the gas equilibrates to the appropriate temperature before
flow measurement.
NOTE One way to facilitate this equilibration is to pass the gas (before flow measurement) through a metal
tube immersed in water maintained at 25 °C.
It is important to exercise great care with the measurement and setting of the flow rate of the gas and to
check direct-reading flowmeters, even those obtained with a direct calibration for the gas used initially,
at regular intervals during testing, with a method capable of measuring accurately the absolute gas
flow at the burner tube.
NOTE One way of doing this is to connect the burner tube with a short length of tubing (about 7 mm internal
diameter) to a soap bubble flowmeter. Passage of a soap film meniscus in a glass tube (e.g. a calibrated burette)
over a known period of time gives an absolute measurement of the flow. Also, fine-control valves that can each be
pre-set to one of the desired gas flow rates, with simple means for switching from one to the other, have proved
helpful.
6.3 Non-flaming ignition sources
The following clauses/subclauses describe ignition sources as follows (see Table 1):
Clause 7: smouldering (cigarette)
Clause 8: Non-flaming electrical ignition sources
8.1 Glow-wire ignition
8.2 Hot-wire ignition
Clause 9: Radiant ignition sources
9.1 Conical radiant ignition
9.2 Other radiant ignition
Clause 10: Infrared heating ignition
Clause 11: Diffusion flame ignition
11.1 Needle flame ignition
11.2 Burning match
11.3 Burners generating 50 W or 500 W flames
Clause 12: Premixed flame ignition
12.1 Premixed burner for 1 kW flame
12.2 Vertical cable tray burners
12.3 Burners for large scale horizontal tests
12.4 Burners for room corner tests
12.5 Burners for individual product heat release tests
Clause 13: Other ignition sources
13.1 Wood cribs
13.2 Paper bags
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Table 1 — Classification of ignition sources
Type of ignition source Standard(s) using ignition source Clause/subclause
Smouldering (cigarette) ISO 8191-1, NFPA 260, NFPA 261 7
Non flaming electrical ignition sources 8
Glow-wire ignition IEC 60695–2-10, IEC 60695–2-11, 8.1
ASTM D6194
Hot-wire ignition IEC/TS 60695–2-20, ASTM D3874 8.2
Radiant ignition sources 9
Conical radiant ignition ISO 5657, ISO 5659-2, ISO 5660-1, 9.1
ASTM E1354, ASTM E1995, NFPA 270
Other radiant ignition ISO 871, ASTM D1929, ASTM E906, 9.2
ASTM E1321
Infrared heating ignition sources ASTM E2058, NFPA 287 10
+
Diffusion flame ignition sources 11
Needle flame ignition IEC 60695–11–5 11.1
Burning match ISO 8191-2, ISO 11925-2 11.2
Burners generating 50 W or 500 W flames IEC/TS 60695–11–3, IEC/TS 60695–11–4, 11.3
ASTM D635, ASTM D5025, UL 94
Premixed flame ignition sources 12
Premixed burner for 1 kW flame IEC 60695–11–2, IEC 60332–1–2, 12.1
IEC 60332–2–1
Vertical cable tray burners IEC 60332–3–10, ASTM D5424, ASTM D5537, 12.2
UL 1666, UL 1685, UL 2556
Burners for large scale horizontal tests ASTM E84, NFPA 262 12.3
Burners for room corner tests ISO 9705,-1 ASTM E2257, NFPA 265, 12.4
NFPA 286
Burners for individual product heat release tests ASTM E1537, ASTM E1590, ASTM E1822, 12.5
NFPA 289
Other ignition sources 13
Wood cribs 13.1
Paper bags 13.2
7 Smouldering (cigarette) ignition sources
7.1 Traditional cigarettes
7.1.1 This source is typical of a common commercial cigarette, which is known to cause many fires
involving upholstered furniture and bedding as discussed in ISO 8191-1. The untipped (unfiltered)
cigarette meets the following:
— length: (70 ± 4) mm
— diameter: (8,0 ± 0,5) mm
— mass: (1,0 ± 0,1) g
— smouldering rate: (12,0/50 ± 3,0/50) min/mm
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7.1.2 The smouldering rate is verified on one specimen from each batch of 10 cigarettes used as
follows:
a) condition the cigarette before the test for 72 h in indoor ambient conditions and then for at least
16 h in an atmosphere having a temperature of (20 ± 5) °C and a relative humidity of (50 ± 20) %;
b) mark the cigarette at 5 mm and 55 mm from the end to be lit;
c) light the cigarette and draw air through it until the tip glows brightly; do not consume more than
3 mm of the cigarette in this operation;
d) impale the cigarette in draught-free air on a horizontal wire spike, inserting not more than 13 mm
of the spike into the unlit end of the cigarette; and
e) record the time taken to smoulder from the 5 mm to the 55 mm mark.
7.1.3 In many countries, including in the European Union and the United States, regulations that apply
to commercial cigarettes mean that they meet the characteristics of reduced ignition propensity (RIP)
cigarettes, by being tested in accordance with ISO 12863 or ASTM E2187. Thus, such RIP cigarettes have
become replacement commercial cigar
...