ISO/DIS 9772

DRAFT INTERNATIONAL STANDARD
ISO/DIS 9772
ISO/TC 61/SC 4 Secretariat: BSI
Voting begins on: Voting terminates on:
2020-03-17 2020-06-09
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

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Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Significance of test .............................................................................................................................................................................................. 2

5 Apparatus ..................................................................................................................................................................................................................... 2

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 ....................................................................................................................................................................................................................12

11 Test report ................................................................................................................................................................................................................13

Annex A (informative) Classification system ............................................................................................................................................14

Bibliography .............................................................................................................................................................................................................................16

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

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.

The main task of technical committees is to prepare International Standards. 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

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.

ISO 9772 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 4, Burning

This fourth edition cancels and replaces the third edition (ISO 9772:2012), which has been technically

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 International Standard gives a method for the determination of the burning behaviour of

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 will be dependent upon its use in complete

It should be noted that the test results obtained by the test specified in this International Standard

alone cannot represent all the aspects of the fire hazard of cellular plastics in end-use conditions.

1.1 This International Standard specifies a small-scale laboratory screening procedure for comparing

the relative burning characteristics of horizontally oriented, small cellular plastic specimens having a

density less than 250 kg⋅m determined in accordance with ISO 845, when exposed to a small-flame

NOTE Another International Standard exists covering flexible cellular plastic and cellular rubber:

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

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 following referenced documents are indispensable for the application of this document. For dated

references, only the edition cited applies. For undated references, the latest edition of the referenced

For the purposes of this International Standard, the terms and definitions given in ISO 13943 and the

persistence of glowing combustion after both removal of the ignition source and the cessation of any

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

space in which the results of experiments are not significantly affected by the local air speed

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

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

4.3 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

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 will be required to obtain 10 valid test results. If

this proves impossible due to non-ignition of all the specimens, then this test is not suitable for these

4.5 The horizontal burning characteristics of some cellular plastic materials might change with time,

5.1 A laboratory fume hood, having an inside volume of at least 0,5 m is used. The chamber shall permit

observation of tests in progress and shall provide a draught free environment whilst allowing normal

thermal circulation of air past the test specimen during burning. The inside surfaces of the chamber shall

be of a dark colour. When a light meter, facing towards the rear of the chamber, is positioned in place of

For safety and convenience, this enclosure (which can be completely closed) shall be fitted with an

extraction device, such as an exhaust fan, to remove products of combustion that might be toxic. The

extraction device shall be turned off during the test and turned on again immediately after the test to

NOTE The amount of oxygen available to support combustion is naturally important for the conduct of these

flame tests. For tests conducted by this method when burning times are protracted, chamber sizes greater than

5.2 P/PF2 laboratory burner, as specified in IEC 60695-11-3, having a barrel length of (100 ± 10) mm

and an internal diameter of (9,5 ± 0,3) mm. The barrel shall not be equipped with an end attachment,

5.3 The burner shall be fitted with a Burner wing top, having an opening of internal length

To ensure the wing top opening is uniform in width, one option is to slide a (1,3 ± 0,05) mm steel wire

5.4 The Support gauze shall be a wire cloth of plain weave, approximately 215 mm long by 75 mm

wide, as shown in Figure 2. It shall consist of (6,4 ± 0,5) mm mesh gauze constructed of (0,9 ± 0,1) mm

diameter stainless steel, plain or low carbon steel wire. The cloth-mesh and wire diameter are to be

determined as described in the Standard Specification for Industrial Woven Wire Cloth, ASTM E2016.

5.5 The gauge-support holder shall consist of two laboratory ring stands with clamps adjustable to

the desired angles and heights. The gauze-support holder shall be constructed from aluminium or steel

— the nearest end of the specimen shall be (13 ± 1) mm above the burner wing top (see Figure 2);

— a means shall be provided for positioning the burner in the correct location relative to the specimen,

preferably with a sliding mechanism and a stop to allow fast movement of the burner flame towards

— the gauze shall be equidistant from the front and back, and from both sides, of the test chamber, and

5.6 There shall be two timing devices, each of which reads to within 1 s or less.

5.7 A Measuring scale graduated in millimetres, shall be used to measure the length, width and

5.8 A Gas supply shall, supply technical-grade methane gas with a purity of at least 98 % and having a

heat content of (37 ± 1) MJ⋅m , with regulator and meter to ensure uniform gas flow.

Other gas mixtures having a heat content of approximately (37 ± 1) MJ⋅m or propane having a heat

content of (94 ± 2) MJ⋅m have been shown to provide similar results when using the procedure of