ISO 7203-3:2019

INTERNATIONAL ISO
STANDARD 7203-3
Third edition
2019-07
Fire extinguishing media — Foam
concentrates —
Part 3:
Specification for low-expansion foam
concentrates for top application to
water-miscible liquids
Agents extincteurs — Émulseurs —
Partie 3: Spécifications pour les émulseurs bas foisonnement destinés
à une application par le haut sur les liquides miscibles à l'eau
Reference number
©
ISO 2019
© ISO 2019
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ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Grades and uses of foam concentrates . 4
4.1 Grades . 4
4.2 Use with sea water . 4
5 Tolerance of the foam concentrate to freezing and thawing . 4
6 Sediment in the foam concentrate . 4
6.1 Sediment before ageing . 4
6.2 Sediment after ageing . 4
7 Determination of viscosity . 4
7.1 Newtonian foam concentrates . 4
7.2 Pseudo-plastic foam concentrates . 4
8 pH of the foam concentrate . 5
8.1 pH limits. 5
8.2 Sensitivity to temperature . 5
9 Expansion and drainage of foam. 5
9.1 General . 5
9.2 Expansion limits . 5
9.3 Drainage limits . 5
10 Test fire performance . 5
11 Marking, packaging and specification sheet . 6
11.1 Marking . 6
11.2 Packaging . 7
11.3 Specification sheet . 7
Annex A (normative) Preliminary sampling and conditioning of the foam concentrate .8
Annex B (normative) Determination of tolerance to freezing and thawing .9
Annex C (normative) Determination of percentage of sediment .11
Annex D (normative) Determination of viscosity for pseudo-plastic foam concentrates .12
Annex E (normative) Determination of expansion and drainage time .14
Annex F (normative) Determination of test fire performance .20
Annex G (informative) Determination of radiation measurement method .24
Annex H (informative) Compatibility .28
Annex I (informative) Small-scale fire test .29
Bibliography .39
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
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www .iso .org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 21, Equipment for fire protection and fire
fighting, Subcommittee SC 6, Foam and powder media and firefighting systems using foam and powder.
This third edition cancels and replaces the second edition (ISO 7203-3:2011), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— Clause 2 “Terms and definitions” has been extended;
— Clause 9 “Expansion and drainage of foam” has been modified to run two tests instead of one and
take the average of both values instead having just one datum;
— Several Figures were corrected;
— Annex F “Determination of test fire performance” has been extended by a scheme of a decision tree
and the acceptable temperature range for testing fire performance has been modified;
— Annex “Typical anticipated performance for various types of foam concentrate” has been removed
from the document.
A list of all parts in the ISO 7203 series can be found on the ISO website.
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 2019 – All rights reserved

Introduction
Firefighting foams are widely used to control and extinguish fires of Class B (flammable liquids) and /
or Class A fuels (Solid materials, usually of an organic nature) and for inhibiting re-ignition.
Foams can be used in combination with other extinguishing media, particularly halons, carbon dioxide
and powders, which are the subject of other International Standards, including, ISO 6183, ISO 7201-1,
ISO 7201-2 and ISO 7202. A specification for foam systems can be found in ISO 7076.
Attention is drawn to Annex H, which deals with the compatibility of foam concentrates, and the
compatibility of foams and powders.
INTERNATIONAL STANDARD ISO 7203-3:2019(E)
Fire extinguishing media — Foam concentrates —
Part 3:
Specification for low-expansion foam concentrates for top
application to water-miscible liquids
1 Scope
This document specifies the essential properties and performance of liquid foam concentrates used
to make low-expansion foams for the control, extinction and inhibition of re-ignition of fires of water-
miscible liquids. Minimum performance on certain test fires is specified.
These foams are suitable for top application to fires of water-miscible liquids. Those foams that also
comply with ISO 7203-1 are also suitable for top application to fires of water-immiscible liquids.
The foam concentrates can be suitable for use in non-aspirating sprayers or for subsurface application
to liquid fires, but requirements specific to those applications are not included in this document.
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 3104, Petroleum products — Transparent and opaque liquids — Determination of kinematic viscosity
and calculation of dynamic viscosity
ISO 3219, Plastics — Polymers/resins in the liquid state or as emulsions or dispersions — Determination of
viscosity using a rotational viscometer with defined shear rate
ISO 3310-1, Test sieves — Technical requirements and testing — Part 1: Test sieves of metal wire cloth
ISO 3506-1, Mechanical properties of corrosion-resistant stainless steel fasteners — Part 1: Bolts, screws
and studs
ISO 7203-2, Fire extinguishing media — Foam concentrates — Part 2: Specification for medium - and high -
expansion foam concentrates for top application to water-immiscible liquids
BS 5117-1.3:1985, Testing corrosion inhibiting, engine coolant concentrate (“antifreeze”). Methods of test
for determination of physical and chemical properties. Determination of freezing point
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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
characteristic value
value declared by
...