ISO 9772:2020

INTERNATIONAL ISO
STANDARD 9772
Fourth edition
2020-11
Cellular plastics — Determination of
horizontal burning characteristics of
small specimens subjected to a small
flame
Plastiques alvéolaires — Détermination des caractéristiques de
combustion de petites éprouvettes en position horizontale, soumises à
une petite flamme
Reference number
©
ISO 2020
© ISO 2020
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ii © ISO 2020 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Significance of test . 2
5 Apparatus . 3
6 Specimens . 7
6.1 Extended application of test results . 7
6.2 Preparation of specimens . 8
7 Conditioning . 8
7.1 Specimens . 8
7.2 Cotton indicator . 9
8 Test procedure . 9
8.1 Adjustment of the flame . 9
8.2 Adjustment of specimen support .10
8.3 Positioning of cotton indicator .11
8.4 Positioning of specimen .11
8.5 Burning procedure .11
8.6 Measurements .11
8.7 Preparation for the next test .12
9 Calculations.12
10 Precision .13
11 Test report .13
Annex A (informative) Classification system .14
Bibliography .16
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
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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).
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iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 4, Burning
behaviour.
This fourth edition cancels and replaces the third edition (ISO 9772:2012), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— better definitions of positions of specimen on wire mesh and of burner have been provided;
— requirements for materials that show different damaged lengths on top and bottom faces of the
specimen have been specified;
— dimensions of cotton indicator have been reduced;
— reference to ASTM E2016 has been added.
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 © ISO 2020 – All rights reserved

Introduction
Cellular plastics are widely used in products for packaging, building, housing, industry and transport,
in various applications. The burning behaviour of cellular plastics is a concern for the fire safety of these
products. This document gives a method for the determination of the burning behaviour of cellular
plastics using a small flame source.
The burning behaviour of cellular plastics is influenced by the test specimen orientation (vertical or
horizontal). This method of test evaluates specimens which are oriented horizontally.
The method described is also intended as a pre-selection test for materials used for components of
devices and appliances. The final acceptance of the material is dependent upon its use in complete
equipment that conforms with the standards applicable to such equipment.
It should be noted that the test results obtained by the test specified in this document alone cannot
represent all the aspects of the fire hazard of cellular plastics in end-use conditions.
INTERNATIONAL STANDARD ISO 9772:2020(E)
Cellular plastics — Determination of horizontal burning
characteristics of small specimens subjected to a small
flame
1 Scope
1.1 This document specifies a small-scale laboratory screening procedure for comparing the relative
burning characteristics of horizontally oriented, small cellular plastic specimens having a density less
−3
than 250 kg⋅m determined in accordance with ISO 845, when exposed to a small-flame ignition source.
[2]
NOTE Another International Standard which covers flexible cellular plastic and cellular rubber is ISO 3582 .
1.2 This method of test is intended for quality assurance and limited product evaluation of cellular
plastic materials under controlled laboratory conditions, and is not intended to assess the fire behaviour
of, for example, building materials or furnishings under actual fire conditions.
1.3 The optional classification system described in Annex A is intended for the pre-selection of cellular
plastic materials for products, including the determination of the ranges of material parameters that give
the same classification (see 6.1).
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 845, Cellular plastics and rubbers — Determination of apparent density
ISO 1923, Cellular plastics and rubbers — Determination of linear dimensions
ISO 10093:2020, Plastics — Fire tests — Standard ignition sources
ISO 13943, Fire safety — Vocabulary
ASTM E2016, Standard Specification for Industrial Woven Wire Cloth
IEC 60695-11-3, Fire hazard testing — Part 11-3: Test flames — 500 W flames — Apparatus and
confirmational test methods
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:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
afterflame
flame that persists after the ignition source has been removed
[SOURCE: ISO 13943:2017, 3.11]
3.2
afterflame time
length of time for which an afterflame (3.1) persists under specified conditions
[SOURCE: ISO 13943:2017, 3.12]
3.3
afterglow
persistence of glowing combustion after both removal of the ignition source and the cessation of any
flaming combustion
[SOURCE: ISO 13943:2017, 3.13]
3.4
afterglow time
length of time for which an afterglow (3.3) persists under specified conditions
[SOURCE: ISO 13943:2017, 3.14]
3.5
extended application of test results
process of predicting a test result, on the basis of one or more existing test results obtained by the
same test, for a product for which a property and/or the intended end-use application(s) are subject to
variation
3.6
draught-free environment
space in which the results of experiments are not significantly affected by the local air speed
4 Significance of test
4.1 Tests conducted on a material under the conditions specified can be of considerable value when
comparing the horizontal burning characteristics of different materials, controlling manufacturing
processes or assessing any changes in formulation or treatment prior to use.
4.2 Assessment of fire hazard requires consideration of factors such as fuel contribution, intensity
of burning (rate of heat release) and products of combustion, as well as environmental factors such as
intensity of source, orientation of exposed material and ventilation conditions.
4.3 The horizontal burning characteristics, as measured by this test procedure, might be affected by
factors such as density, any anisotropy of the cellular material, its melting characteristics, its colour and
its thickness.
4.4 Certain materials might shrink from the applied flame without igniting. In this event, the test results
are not valid, and additional test specimens are required to obtain
...