SIST EN ISO 4589-2:2000
(Main)Plastics - Determination of burning behaviour by oxygen index - Part 2: Ambient-temperature test (ISO 4589-2:1996)
Plastics - Determination of burning behaviour by oxygen index - Part 2: Ambient-temperature test (ISO 4589-2:1996)
Kunststoffe - Bestimmung des Brandverhaltens durch den Sauerstoff-Index - Teil 2: Bestimmung des Sauerstoff-Index (OI) bei Umgebungstemperatur (ISO 4589-2:1996)
In diesem Teil von ISO 4589 werden Verfahren zur Bestimmung der minimalen Sauerstoffkonzentration in Gemischen mit Stickstoff, die die Verbrennung senkrecht angeordneter kleiner Probekörper unter festgelegten Prüfbedingungen unterstützen, festlegt. Die Ergebnisse sind als Sauerstoff-Index-Werte festgelegt.
Plastiques - Détermination du comportement au feu au moyen de l'indice d'oxygene - Partie 2: Essai a la température ambiante (ISO 4589-2:1996)
Polimerni materiali - Določanje gorljivosti s kisikovim indeksom - 2. del: Preskus pri sobni temperaturi (ISO 4589-2:1996)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 4589-2:2000
01-maj-2000
3ROLPHUQLPDWHULDOL'RORþDQMHJRUOMLYRVWLVNLVLNRYLPLQGHNVRPGHO 3UHVNXV
SULVREQLWHPSHUDWXUL ,62
Plastics - Determination of burning behaviour by oxygen index - Part 2: Ambient-
temperature test (ISO 4589-2:1996)
Kunststoffe - Bestimmung des Brandverhaltens durch den Sauerstoff-Index - Teil 2:
Bestimmung des Sauerstoff-Index (OI) bei Umgebungstemperatur (ISO 4589-2:1996)
Plastiques - Détermination du comportement au feu au moyen de l'indice d'oxygene -
Partie 2: Essai a la température ambiante (ISO 4589-2:1996)
Ta slovenski standard je istoveten z: EN ISO 4589-2:1999
ICS:
13.220.40 Sposobnost vžiga in Ignitability and burning
obnašanje materialov in behaviour of materials and
proizvodov pri gorenju products
83.080.01 Polimerni materiali na Plastics in general
splošno
SIST EN ISO 4589-2:2000 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 4589-2:2000
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SIST EN ISO 4589-2:2000
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SIST EN ISO 4589-2:2000
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SIST EN ISO 4589-2:2000
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SIST EN ISO 4589-2:2000
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SIST EN ISO 4589-2:2000
INTERNATIONAL IS0
STANDARD
4589-2
First edition
1996-07-I 5
Plastics - Determination of burning
behaviour by oxygen index - .
Part 2:
Ambient-temperature test
P/as tiques - D&termination du comportement au feu au moyen de
I ‘indice d ‘oxygkne -
Partie 2: Essai 6 la temperature ambiante
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SIST EN ISO 4589-2:2000
IS0 4589-2: 1996
Contents
Page
1
1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
2 Normative references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
3 Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
4 Principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
5 Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5
6 Calibration of equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
7 Preparation of test specimens
8
8 Procedure for determination of oxygen index . . . . . . . . . . . . . . . . . . . . . . . . . .
12
9 Calculations and expression of results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10 Procedure C - Comparison with a specified minimum value of the
oxygen index (short procedure) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
14
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11 Test report
Annexes
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
A Calibration of equipment
17
Calculation of oxygen concentration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B
18
Typical test results sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C
20
D Results obtained by interlaboratory trials on type VI specimens
0 IS0 1996
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
ii
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SIST EN ISO 4589-2:2000
0 IS0 IS0 4589-2: 1996(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work
of preparing International Standards is normally carried out through IS0
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. IS0
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard IS0 4589-2 was prepared by Technical Committee
ISO/TC 61, Plastics, Subcommittee SC 4, Burning behaviour.
Together with parts 1 and 3 (see below), this part of IS0 4589 cancels and
replaces IS0 4589: 1984.
This revision has been prepared to introduce the following changes rela-
tive to the 1984 edition:
to amplify the requirements for equipment calibration (see clause 6
a)
and annex A);
to reduce the permissible deviations for the gas flow rate through the
b)
chimney at 40 mm/s from + IO mm/s to ~fr 2 mm/s;
to introduce a relatively short procedure, as procedure C, intended for
d
use for comparison purposes, to determine whether or not the oxygen
index of a material lies above a specified minimum value;
to introduce a new specimen (form VI) and a corresponding procedure
d
for testing of thin films. Precision data for the new procedure are given
in an informative annex.
IS0 4589 consists of the following parts, under the general title
P/as tics - Determination of burning behaviour by oxygen index:
- Part 7: Guidance
- Part 2: Ambient-temperature test
- Part 3: Elevated-temperature test
Annexes A and B form an integral part of this part of IS0 4589. Annexes
C and D are for information only.
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SIST EN ISO 4589-2:2000
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SIST EN ISO 4589-2:2000
INTERNATIONAL STANDARD 0 IS0 IS0 4589-2: 1996(E)
Plastics - Determination of burning behaviour by
oxygen index -
Part 2:
Ambient-temperature test
correlation with flammability behaviour under other
1 Scope
fire conditions is implied.
Results obtained in accordance with this part of
This part of IS0 4589 specifies methods for deter-
IS0 4589-2 must not be used to describe or appraise
mining the minimum concentration of oxygen, in ad-
the fire hazard presented by a particular material or
mixture with nitrogen, that will support combustion
shape under actual fire conditions, unless used as one
of small vertical test specimens under specified test
element of a fire risk assessment that takes into ac-
conditions. The results are defined as oxygen index
count all of the factors pertinent to the assessment
values.
of the fire hazard of a particular application for the
material.
Methods are provided for testing materials that are
NOTES
self-supporting in the form of vertical bars or sheet
up to IO,5 mm thick. These methods are suitable for
1 It may not be possible to apply these methods satisfac-
solid, laminated or cellular materials characterized by
torily to materials that exhibit high levels of shrinkage when
an apparent density greater than 100 kg/m3. The
heated, e.g. highly oriented thin film.
methods may also be applicable to some cellular ma-
terials having an apparent density of less than
2 For assessing the flame propagation properties of cellu-
100 kg/m3. A method is provided for testing flexible lar materials of density < 100 kg/m3, attention is drawn to
the method of IS0 3582:1978, Cellular plastic and cellular
sheet or film materials while supported vertically.
rubber materials - Laboratory assessment of horizontal
burning characteristics of small specimens subjected to a
For comparative purposes, a procedure is provided for
small flame, for testing horizontal burning characteristics.
determining whether or not the oxygen index of a
material lies above some specified minimum value.
Oxygen index results obtained using the methods 2 Normative references
described in this part of IS0 4589 can provide a sen-
sitive measure of the burning characteristics of ma- The following standards contain provisions which,
through reference in this text, constitute provisions
terials under certain controlled laboratory conditions,
of this part of IS0 4589. At the time of publication, the
and hence may be useful for quality control purposes.
editions indicated were valid. All standards are subject
The results obtained are dependent upon the shape,
to revision, and parties to agreements based on this
orientation and isolation of the test specimen and the
conditions of ignition. For particular materials or appli- part of IS0 4589 are encouraged to investigate the
possibility of applying the most recent editions of the
cations, it may be necessary or appropriate to specify
standards indicated below. Members of IEC and IS0
different test conditions. Results obtained from test
maintain registers of currently valid International
specimens of differing thickness or by using different
Standards.
ignition procedures may not be comparable and no
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SIST EN ISO 4589-2:2000
IS0 4589-2: 1996(E)
IS0 293: 1986, Plastics - Compression moulding test
5 Apparatus
specimens of thermoplastic materials.
5.1 Test chimney, consisting of a heat-resistant
IS0 294: 1995, Plastics - Injection moulding of test
glass tube supported vertically on a base through
specimens of thermoplastic materials.
which oxygen-containing gas mixtures can be intro-
duced (see figures 1 and 2).
IS0 295:1991, Plastics - Compression moulding of
test specimens of thermose tting materials.
The preferred dimensions of the chimney are
450 mm minimum height and 95 mm minimum di-
IS0 2818:1994, Plastics - Preparation of test speci-
ameter.
mens by machining.
The upper outlet shall be restricted as necessary by
IS0 2859-l : 1989, Sampling procedures for inspection
an overhead cap having an outlet small enough to
by attributes - Part 7: Sampling plans indexed by
produce an exhaust velocity of at least 90 mm/s from
acceptable quality level (AQL) for lot-by-lot
that outlet.
inspection.
NOTE 3 A cap converging to an outlet of 40 mm diam-
I SO 2859-2: 1985, Sampling procedures for inspection
eter at a level at least 10 mm above the top of the cylindrical
by attributes - Part 2: Sampling plans indexed by
chimney has been found satisfactory.
limiting quality (LC?) for isolated lot inspection.
Chimneys of other dimensions, with or without re-
- Multipurpose test speci-
IS0 3167:1993, Plastics
stricted outlets, may be used, if shown to give equiv-
mens.
alent results. The bottom of the chimney, or the base
upon which the chimney is supported, shall incorpo-
rate a device for distributing evenly the gas mixture
3 Definition entering the chimney. The preferred device comprises
a suitable diffuser and a mixing chamber with metal
For the purposes of this part of IS0 4589, the follow-
foil. Other devices, such as radial manifolds, may be
ing definition applies.
used, if shown to give equivalent results. A porous
screen may be mounted below the level of the spec-
3.1 oxygen index: The minimum concentration of
imen holder,. to prevent falling combustion debris
oxygen, by volume percentage, in a mixture of oxygen
from fouling the gas entry and distribution paths.
and nitrogen introduced at 23 “C zf~ 2 “C that will just
The chimney support may incorporate a levelling de-
support combustion of a material under specified test
vice and indicator, to facilitate vertical alignment of the
conditions.
chimney and a test specimen supported therein. A
dark background may be provided to facilitate obser-
vation of flames within the chimney.
4 Principle
A small test specimen is supported vertically in a
5.2 Test specimen holder, suitable for supporting
mixture of oxygen and nitrogen flowing upwards
a specimen vertically in the centre of the chimney.
through a transparent chimney. The upper end of the
For self-supporting materials, the specimen shall be
specimen is ignited and the subsequent burning be-
held by a small clamp which is at least 15 mm away
haviour of the specimen is observed to compare the
period for which burning continues, or the length of from the nearest point at which the specimen may
specimen burnt, with specified limits for such burning. burn before the extent-of-burning criterion is ex-
ceeded. For supported film or sheet test specimens,
By testing a series of specimens in different oxygen
the specimen shall be supported by both vertical
concentrations, the minimum oxygen concentration is
edges in a frame equivalent to that illustrated by fig-
estimated (see 8.6).
ure2, with reference marks at 20 mm and 100 mm
Alternatively, for comparison with a specified mini-
below the top of the frame.
mum oxygen index value, three test specimens are
tested using the relevant oxygen concentration, at The profile of the holder and its support should pref-
least two of which are required to extinguish before erably be smooth to minimize induction of turbulence
any relevant burning criterion is exceeded. in the rising flow gas.
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SIST EN ISO 4589-2:2000
IS0 4589-2: 1996(E)
Dimensions in millimetres
Chimney
r (height 450 mm,
diameter 95 mm)
Outlet, @ 40 mm
,-- Test specimen
Chimney cap
- Specimen holder
Glass chimney
Suitable device for restricting
chimney outlet (see 5.1)
Wire-mesh
debris screen
/-
Oxygen/nitroge
mixture
y Igniter
e
- Diffuser ring
Alternative gas flow measuring
devices (see note S to 5.4)
4 Pressure gauge 7 Needle valve
1 Gas premixing point
pressure regulator 8 Gas flow meter
2 Cut-off valve 5 Precision
3 Orifice in holder 6 Filter
Figure 1 - Diagram of typical apparatus for determination of oxygen index
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SIST EN ISO 4589-2:2000
IS0 4589-2: 1996(E) 0 IS0
Dimensions in millimetres with tolerances of
+ 0,25 mm
38
I
/
Upper reference mark
---
Lower reference mark \
NOTE - The test specimen is held securely along both upright edges between forks made of stainless steel.
Figure 2 - Support frame for non-self-supporting test specimens
5.3 Gas supplies, comprising pressurized sources ing or sampling the gas supply for moisture content,
of oxygen and/or nitrogen not less than 98 % (m/m)
unless the moisture content of the gas supplies is
pure and/or clean air [containing 20,9 % (WV)
known to be acceptable.
oxygen], as appropriate.
The constituent gas supply lines shall be linked in a
The moisture content of the gas mixture entering the
manner which thoroughly mixes the gases, before
chimney shall be < 0,l % (m/m), unless the results
they enter the gas distribution device at the base of
have been shown to be insensitive to higher moisture
the chimney, so that the variation in oxygen concen-
levels in the gas mixture. The gas supply system shall
tration in the gas mixture rising in the chimney, below
incorporate a drying device, or provision for monitor-
the level of the test specimen, is < 0,2 % (V/v).
4
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SIST EN ISO 4589-2:2000
Q IS0 IS0 4589=2:1996(E)
NOTE 4 It should not be assumed that bottled oxygen
5.7 Fume extraction system, providing sufficient
or nitrogen will always contain < 0,l % (m/m) of water;
ventilation or exhaust to remove fumes or soot
moisture contents of 0,003 % (m/m) to 0,Ol % (m/m) are
expelled from the chimney without disrupting the gas
typical for commercial supplies as filled bottles of purity
flow rate or temperatures in the chimney.
> 98 % (m/m), but as such bottled gases are depressurized
to below about 1 MPa, the moisture content of the gas
NOTE 6 If soot-generating materials are being tested, the
drawn off may rise above 0,l % (m/m).
glass chimney may require cleaning to maintain good visi-
bility, and the gas inlets, or inlet screen, and temperature
sensor (if fitted) may also require cleaning to function prop-
5.4 Gas measurement and control devices, suit- erly. Suitable precautions should be taken to protect per-
sonnel from noxious materials or burns during testing or
able for measuring the concentration of oxygen in the
cleaning operations.
gas mixture entering the chimney with an accuracy
of + 0,5 % (V/v) of the mixture and for adjusting the
5.8 Tool for preparing rolled film, consisting of a
concentration with a precision of - + 0,l % (V/v) of the
stainless-steel rod of 2 mm diameter, with a slit in
mixture when the gas velocity through the chimney
one end (see figure3).
is 40 mm/s + 2 mm/s at 23 “C + 2 “C.
- -
Means shall be provided for checking or ensuring that
6 Calibration of equipment
the temperature of the gas mixture entering the
chimney is 23 “C rtr: 2 “C. If this involves an internal
For compliance with this method, calibrate the equip-
probe, its position and profile shall be designed to
ment periodically in accordance with the instructions
minimize induction of turbulence within the chimney.
given in annex A so that the maximum interval be-
tween recalibration and use complies with the periods
NOTE 5 Systems of measurement and control that have
stated in table 1.
proved satisfactory include the following:
7 Preparation of test specimens
needle valves on individual and mixed gas supply lines,
a)
a paramagnetic oxygen analyser that continuously
samples the mixed gas, and a flowmeter to indicate
7.1 Sampling
when the gas flow through the chimney is within the
required limits;
Obtain a sample sufficient for preparation of at least
15 test specimens. The sample shall be taken, if rel-
pressure regulators
calibrated orifices, and pressure
b) gas
evant, in accordance with the material specification,
ividu al gas supply lines;
gauges on the ind
otherwise in accordance with IS0 2859-l or
IS0 2859-2, as applicable.
needle valves and ca flowmeters on the i ndivid-
d
ual gas lines.
supply
NOTE 7 For a material for which the oxygen index is
Systems b) and c) may require calibration after assembly to known to within + 2, 15 test specimens may be sufficient.
ensure that the cumulative errors of the component parts For materials of unknown oxygen index, or which exhibit
erratic burning characteristics, between 15 and 30 test
do not exceed the requirements of 5.4.
specimens may be required.
5.5 Flame igniter, comprising a tube that can be
Table 1 - Equipment calibration frequencies
inserted into the chimney to apply to the test speci-
men a flame issuing from an outlet of
Maximum
Item
2 mm + 1 mm diameter at the end of the tube.
- period
The flame fuel shall be propane, without premixed air. Gas system joints (as required by clause
A.1 in annex A)
The fuel supply shall be adjusted so that the flame
will project 16 mm + 4 mm vertically downwards
a) for joints disturbed during use or clean- Immedi-
from the outlet when the tube is vertical within the
ing of the apparatus ately
chimney and the flame is burning within the chimney
b) for undisturbed equipment 6 months
atmosphere.
Cast PMMA sample 1 month
Gas flow rate controls 6 months
Oxygen concentration controls 6 months
5.6 Timing device, capable of measuring periods
up to 5 min with an accuracy of -+ 0,5 s.
-
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SIST EN ISO 4589-2:2000
OS0 4589-Z: 1996(E)
Dimensions in millimetres
0,3 mm slit to hold one
end of film to be rolled
it-
Figure 3 -
Tool for preparing rolled-film specimens
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SIST EN ISO 4589-2:2000
0 IS0
IS0 4589-2: 1996(E)
Note the position and orientation of test specimens
7.2 Test specimen dimensions and
with respect to any asymmetry in the sample material
preparation
(see note IO).
Using, if applicable, procedures that comply with the
NOTES
appropriate material specification (see note 8) or IS0
methods (see note 9) for specimen preparation,
8 Some material specifications may require choice and
mould or cut test specimens that satisfy the dimen-
identification of the “state of the test specimen” used; e.g.
sions specified for the most appropriate specimen
in a “defined state” or a “basic state” for a styrene-based
form given in table2. polymer or copolymer.
To prepare a rolled specimen from a thin film, use the 9 In the absence of a relevant specification, one or more
procedures from IS0 293, IS0 294, IS0 295, IS0 2818 or
tool described in 5.8. Insert one corner of the film into
IS0 3167 may be used.
the slit and then wind the film round the rod in a spiral
of 45”. Ensure that the 45” angle is maintained during
10 Oxygen index results may be significantly affected by
the winding process so that the film reaches exactly
differences in ease of ignition or burning behaviour, due to
to the end of the tool, to produce a test piece of the
material inhomogeneity (e.g. different levels of shrinkage
correct length, as shown in figure3. After the winding
when heated for specimens cut in different directions from
is finished, tape the last end of the roll while the ma-
asymmetrically oriented thermoplastics film).
terial is still on the stainless steel rod to prevent
11 If a thin film burns in such a manner that erratic com-
loosening. Then pull the rod out of the rolled film. Cut
bustion behaviour including heat shrinkage and fluctuation
off the rolled film at a distance of 20 mm from the top
of data results, the specimen form VI, i.e. a rolled film,
end (see figure4).
should preferably be used. It gives reproducible results,
similar to those given by specimen form I. Precision data
Ensure that the surfaces of the specimens are clean
obtained by interlaboratory trials on specimen form VI are
and free from flaws that could affect burning behav-
given in annex D.
iour, e.g. peripheral moulding flash or burrs from ma-
chining.
Table 2 - Test specimen dimensions
Dimensions
Test specimen
Typical use
Length Width Thickness
formI)
mm mm mm
I 80 to 150 IO + 0,5 4 + 0,25 For moulding materials
- -
II 80 to 150 10 + 0,5 10 + 0,5 For cellular materials
- -
III 2) 80 to 150 10 + 0,5 < IO,5 For sheet materials “as received”
-
IV 70 to 150 6,5 + 0,5 3 + 0,25 Alternative size for self-supporting moulding or sheet ma-
- -
terials, for electrical purposes
V2) 140 -; 52 + 0,5 < IO,5 For flexible film or sheet
-
VI 3) 140 to 200 20 0,02 to 0,lO 4) For thin film “as received”; limited to the film that can be
rolled by the specified rod41
1) Test specimens of forms I, II, III and IV are suitable for materials that are self-supporting at these dimensions. Test
specimens of form V are suitable for materials that require support during testing.
2) Results obtained using form Ill or form V test specimens may only be comparable for specimens of the same form and
thickness. It is assumed that the amount of variation in thickness for such materials will be controlled by other standards.
3) The test specimen of form VI is suitable for a thin film that is self-supporting when it is rolled. Dimensions in the table
are of an original film from which the rolled form is made. See 7.2 for the preparation of rolled film.
4) The film is limited to thicknesses that can be rolled by the specified rod (see figure3). If the film is very thin,, it may
be necessary to combine two or more films together in the preparation of the rolled film so as to obtain results similar to
those normally obtained with specimen form VI.
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SIST EN ISO 4589-2:2000
0 IS0
IS0 4589-2: 1996(E)
Dimensions in millimetres
Figure 4 - Rolled specimen
they shall be marked at 10 mm and at 60 mm from
7.3 Marking of test specimens
the end to be ignited.
7.3.1 General
7.4 Conditioning
For monitoring the distance over which a specimen
burns, it may be marked with transverse lines at one
Unless otherwise specified in other established stan-
or more levels which are dependent upon the speci-
dards, each test specimen shall be conditioned for at
men form and the ignition procedure to be used.
least 88 h at 23 “C + 2 “C and (50 + 5) % relative
Self-supporting specimens are preferably marked on
humidity immediatelyprior to use.
-
at least two adjacent faces. If wet inks are used, the
marks shall be dry before the specimen is ignited.
NOTE 12 Specimens of cellular materials that may con-
tain volatile flammable material should preferably be purged
7.3.2 Marks for testing by top surface ignition of such volatile material prior to conditioning at 23 “C and
50 % relative humidity. Test specimens may be purged
satisfactorily by pre-conditioning in suitable ventilated ovens
Test specimens of form I, II, III, IV or VI to be tested
for 168 h. Larger blocks of such materials may require
in accordance with procedure A (see 8.2.2) shall be
longer pre-treatment. It is important that facilities for cutting
marked 50 mm from the end to be ignited.
specimens from cellular material that may contain volatile
flammable material are suitable for the hazards involved.
7.3.3 Marks for testing by propagating ignition
The reference marks for testing specimens of form V
are carried by the supporting frame (see figure2), but
8 Procedure for determination of oxygen
such specimens may be marked at 20 mm and at
index
100 mm from the end to be ignited, for convenience
when testing heat-stable materials.
NOTE 13
For a shortened procedure to determine com-
pliance relative to a specified minimum value of the oxygen
If specimens of forms I, II, III, IV and VI are to be
index, without determining the actual oxygen index of the
tested in accordance with procedure B (see 8.2.3),
material under test, see clause 10.
8
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SIST EN ISO 4589-2:2000
0 IS0
IS0 4589=2:1996(E)
a) for specimen forms I, II, III, IV and VI (see
8.1 Setting up the apparatus and test
table2), use procedure A (top surface ignition) as
specimen
described in 8.2.2;
8.1.1 Maintain the ambient temperature for the test
b) for specimen form V, use procedure B (propagat-
ap.paratus at 23 “C + 2 “C. If necessary, keep the
ing ignition) as described in 8.2.3.
test specimens in an-enclosure at 23 “C + 2 “C and
(50 + 5) % relative humidity from which-each test Ignition shall imply, for the purposes of this part of
-
specimen may be taken when required. IS0 4589, the initiation of flaming combustion.
NOTES
8.1.2 Recalibrate equipment components, if
necessary (see clause 6 and annex A). 14 For tests on materials that exhibit steady burning and
spread of combustion in oxygen concentrations at, or close
to, their oxygen index value, or for self-supporting speci-
Select an initial concentration of oxygen to be
8.1.3
mens of < 3 mm thickness, procedure B (with specimens
used. When possible, base this on experience of re-
marked in accordance with 7.3.2) may be found to give
sults for similar materials. Alternatively, try to ignite a
more consistent results than procedure A. Procedure B may
then be used for specimens of form I, II, III, IV or VI.
test specimen in air, and note the burning behaviour.
If the specimen burns rapidly, select an initial con-
15 Some materials may exhibit a non-flaming type of
centration of about 18 % (V/v) of oxygen; if the test
combustion (e.g. glowing combustion) instead of, or at a
specimen burns gently or unsteadily, select an initial
lower oxygen concentration than that required for, flaming
oxygen concentration of about 21 % (VW); if the
combustion. When testing such materials, it is necessary to
specimen does not continue to burn in air, select an
identify the type of combustion for which the oxygen index
initial concentration of at least 25 % (VW), depending
is required or measured.
upon the difficulty of ignition or the period of burning
before extinguishing in air.
8.2.2 Procedure A - Top surface ignition
For top surface ignition, the igniter is used to initiate
8.1.4 Ensure that the test chimney is vertical (see
burning only on the top surface of the upper end of
figure I). Mount a specimen vertically in the centre of
the specimen.
the chimney so that the top of the specimen is at
least 100 mm below the open top of the chimney and
Apply the lowest visible part of the flame to the top
the lowest exposed part of the specimen is at least
of the specimen using a sweeping motion, if necess-
100 mm above the top of the gas distribution device
ary, to cover the whole surface, but taking care not to
at the base of
...
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