ISO 23949:2023

Plastics - Application of spread of flame test to plastic pipes

This document specifies test methods for assessing the flame spread of plastic pipes including fiberglass reinforced plastic (FRP) pipes. This document is applicable to plastic pipes including FRP pipes for use in ships, air crafts and vehicles.

Plastiques — Application de l’essai de propagation de flamme aux canalisations plastiques

General Information

• Status: Published
• Publication Date: 17-Apr-2023
• ICS: 13.220.40 - Ignitability and burning behaviour of materials and products
• ICS: 23.040.20 - Plastics pipes
• ICS: 83.080.01 - Plastics in general
• Technical Committee: ISO/TC 61/SC 4 - Burning behaviour
• Drafting Committee: ISO/TC 61/SC 4/WG 9 - Composites and semi-finished products
• Current Stage: 6060 - International Standard published
• Start Date: 18-Apr-2023
• Due Date: 21-Jul-2023
• Completion Date: 18-Apr-2023

Overview

ISO 23949:2023 - Plastics - Application of spread of flame test to plastic pipes - specifies how to assess surface flame spread for plastic pipes, including fiberglass reinforced plastic (FRP) pipes, primarily for use in ships, aircraft and vehicles. The standard adapts the lateral spread test of ISO 5658-2:2006 to pipe geometries and provides detailed specimen preparation, conditioning, test procedures and reporting requirements to ensure repeatable reaction-to-fire results.

Key topics and technical requirements

• Test principle: Uses the ISO 5658-2 lateral spread-of-flame method with additional pipe-specific protocols (radiant heat flux exposure, time-to-ignition, lateral spread and extinguishment observations).
• Specimen preparation:
  • Pipe sections cut to 800 mm length.
  • For rigid pipes: lateral cutting rules depending on inner diameter (e.g., curvature height ≤ 5 mm if ID > 10 mm; split into two parts if 5 mm < ID ≤ 10 mm; full section used if ID ≤ 5 mm).
  • Wall thickness: test at full thickness if ≤ 40 mm; reduce unexposed face to 40 mm if > 40 mm (record original thickness).
  • Assembly: place sections side-by-side on a non-combustible backing board (155 mm × 800 mm, 20 mm thick, nominal density 900 ± 100 kg/m³) and secure with thin metal wires or wire mesh where deformation can occur.
• Number of specimens: At least six specimens unless agreed otherwise.
• Conditioning: Constant mass at (23 ± 2) °C and (50 ± 5) % RH; constant mass defined by two weighings 24 h apart differing by ≤ 0.1% or 0.1 g.
• Test execution: Use ISO 5658-2 apparatus and calibration; account for possible large fume/gas production for thick-walled pipes and ensure adequate exhaust.
• Results and calculations: Derive average heat for sustained burning (Qsb) and critical heat flux at extinguishment (CFE) per ISO 5658-2.
• Reporting: Include time to reach standard 50 mm positions, observations, derived characteristics (Q and C), specimen description, test conditions, number of specimens, ignition time and limitations.

Applications and practical value

• Ensures consistent, repeatable assessment of flame spread on plastic and FRP piping used in maritime, aviation, automotive and land-based installations.
• Supports product development, material selection and compliance evidence for designers, shipbuilders, aircraft and vehicle manufacturers, and fire safety engineers.
• Useful for manufacturers and testing laboratories seeking standardized methods to demonstrate fire performance of pipe systems and to inform risk assessments and regulatory submissions.

Who should use this standard

• Pipe and composite (FRP) manufacturers
• Accredited fire testing laboratories
• Maritime, aviation and automotive OEMs and suppliers
• Fire safety engineers, certification bodies and regulators

Related standards

• ISO 5658-2:2006 - Reaction-to-fire tests - Spread of flame - Part 2 (lateral spread)
• ISO 13943 - Fire safety - Vocabulary
• IMO guidelines on use of plastic pipes (referenced in the introduction)

Keywords: ISO 23949:2023, spread of flame test, plastic pipes, FRP pipes, ISO 5658-2, flame spread, reaction-to-fire, pipe fire testing, maritime fire safety.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 23949
First edition
2023-04
Plastics — Application of spread of
flame test to plastic pipes
Plastiques — Application de l’essai de propagation de flamme aux
canalisations plastiques
Reference number
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
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or ISO’s member body in the country of the requester.
ISO copyright office
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Phone: [phone]
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Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Test apparatus .1
6 Test specimen . 2
6.1 General . 2
6.2 Number of test specimens . 2
6.3 Thickness of the test specimen . 2
6.4 Rigid pipes . 2
6.5 Flexible pipes . 4
7 Conditioning of specimens . 4
8 Test procedures . 4
8.1 General . 4
8.2 Additional test procedures for pipes . 4
9 Calculation of the test results . 5
10 Precision of the test .5
11 Test report . 5
Annex A (informative) Example of the test results on plastic pipes . 7
Bibliography .10
iii
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
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electrotechnical standardization.
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described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO document should be noted. This document was drafted in accordance with the
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www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 61 Plastics, Subcommittee SC 4, Burning
behaviour.
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
Introduction
Plastic pipes and fiberglass reinforced plastic (FRP) pipes exhibit corrosion resistance against water
including sea water and liquid chemicals. These pipes have been used on ships in various applications,
such as piping supplying fresh water, sanitary and drain piping, sea-water piping and liquid cargo
piping.
The International Maritime Organization (IMO) adopted guidelines on use of plastic pipes (see
Reference [1]). These guidelines contain requirements on the fire performance of plastic pipes and of
FRP pipes to be used on-board ships. These guidelines also contain brief explanation of test procedures
applicable to flame spread for plastics pipes and FRP pipes. However, the details provided regarding
these fire tests are very short and are insufficient to conduct these tests in a uniform manner.
This document was developed based on the IMO Guidelines, ISO 5658-2:2006, Annex E and the NATO
[2]
Reaction-to-fire tests for materials surface spread of flame (see AFAP – 4 Edition 3 ). It provides
detailed descriptions of the test methods for assessing the flame spread of plastic pipes and FRP pipes.
This document is applicable, on a voluntary basis, to plastic pipes and to FRP pipes for use in ships, air
crafts, vehicles, building and land-based structures.
v
INTERNATIONAL STANDARD ISO 23949:2023(E)
Plastics — Application of spread of flame test to plastic
pipes
1 Scope
This document specifies test methods for assessing the flame spread of plastic pipes including fiberglass
reinforced plastic (FRP) pipes. This document is applicable to plastic pipes including FRP pipes for use
in ships, air crafts and vehicles.
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 5658-2:2006, Reaction to fire tests — Spread of flame — Part 2: Lateral spread on building and
transport products in vertical configuration
ISO 13943, Fire safety — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5658-2, ISO 13943 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 https:// www .electropedia .org/
4 Principle
The test procedure in this document uses the test method given in ISO 5658-2 to evaluate the surface
spread of flame characteristics of test specimens. Additional test protocols and procedures for testing
plastic pipes are also specified in this document.
The test specimen is constructed in such a way that plastic pipes are cut to a length of 800 mm. The
length of cut pipes are further cut laterally. The cut pipe sections are placed side by side on a non-
combustible backing board, with dimensions of 155 mm wide and 800 mm long. The test specimens are
secured by means of narrow metal wires. The test specimen is exposed to a graded radiant heat flux
field, as specified in ISO 5658-2.
Data on critical heat flux at extinguishment and average heat for sustained burning are derived from
observations of time to ignition, lateral spread and extinguishment of flame along the surface of the
test specimen which is exposed such that the surface is vertical and the longer edge in horizontal.
...