ISO 8502-5:2025

Preparation of steel substrates before application of paints and related products — Tests for the assessment of surface cleanliness — Part 5: Measurement of chloride on steel surfaces prepared for painting (ion detection tube method)

This document describes a field test for the measurement of chloride ions using special detection tubes. With suitable surface sampling techniques, this document is applicable to steel surfaces before and after cleaning, as well as to painted surfaces between applications of coats.

Préparation des subjectiles d’acier avant application de peintures et de produits assimilés — Essais pour apprécier la propreté d’une surface — Partie 5: Mesurage des chlorures sur les surfaces d’acier préparées pour la mise en peinture (méthode du tube détecteur d’ions)

Le présent document décrit une méthode d’essai in situ pour le mesurage des ions chlorure à l’aide de tubes détecteurs spécifiques. Avec des techniques d’échantillonnage de surface appropriées, le présent document est applicable aux surfaces d’acier avant et après nettoyage ou aux surfaces peintes entre les applications de revêtements.

General Information

• Status: Published
• Publication Date: 18-Jun-2025
• ICS: 25.220.10 - Surface preparation
• Technical Committee: ISO/TC 35/SC 12 - Preparation of steel substrates before application of paints and related products
• Drafting Committee: ISO/TC 35/SC 12 - Preparation of steel substrates before application of paints and related products
• Current Stage: 6060 - International Standard published
• Start Date: 19-Jun-2025
• Due Date: 13-Jun-2026
• Completion Date: 19-Jun-2025

Relations

• Consolidates: EN ISO 8502-5:2025 - Preparation of steel substrates before application of paints and related products - Tests for the assessment of surface cleanliness - Part 5: Measurement of chloride on steel surfaces prepared for painting (ion detection tube method) (ISO 8502-5:2025)
• Effective Date: 12-Feb-2026
• Revises: ISO 8502-5:1998 - Preparation of steel substrates before application of paints and related products — Tests for the assessment of surface cleanliness — Part 5: Measurement of chloride on steel surfaces prepared for painting (ion detection tube method)
• Effective Date: 06-Jun-2022

Overview

ISO 8502-5:2025 is an international standard by ISO that specifies a practical field test for measuring chloride ion contamination on steel surfaces prepared for painting. Using an ion detection tube method, this standard ensures reliable assessment of surface cleanliness for steel structures before and after cleaning, and at intermediary stages during multilayer painting processes. Accurate evaluation of chloride levels is vital because residual salts can undermine the effectiveness of paint systems, leading to premature corrosion.

Key Topics

• Field measurement of chloride ions using special detection tubes
• Assessment of surface cleanliness before application of paints and related products
• Applicable surfaces: uncoated, cleaned, or partially coated steel
• Sampling techniques that allow efficient extraction of water- or acid-soluble chlorides
• Procedures for extraction and measurement of contaminants
• Interpretation and reporting of chloride concentration results

Process Highlights

• Use of a silver chromate-filled detection tube for simple and accurate chloride quantification
• Extraction protocols suitable for various surface conditions, referencing ISO 8502-2, ISO 8502-6, and ISO 8502-15
• No laboratory analysis required, supporting on-site decision making

Applications

ISO 8502-5:2025 is used across a range of industries and project types, wherever protective paints are applied to steel. Typical scenarios include:

• Corrosion protection: Guarantees optimal performance of coatings for steel bridges, pipelines, storage tanks, and marine structures.
• Quality control: Allows for on-site verification of surface readiness prior to painting, ensuring compliance with project specifications.
• Maintenance and refurbishment: Offers a field-appropriate method to assess surface cleanliness between maintenance coating layers.
• Project documentation: Supports traceability and compliance for standards-driven construction or renovation works.

Implementing this standard helps prevent coating failures related to invisible surface contamination, minimizes premature corrosion risk, and extends the service life of steel assets. Its field-friendly, procedural approach improves productivity and promotes quality assurance in painting and anti-corrosion treatments.

Related Standards

Adherence to ISO 8502-5:2025 typically involves reference to other surface cleanliness and corrosion protection standards, including:

• ISO 8502-2: Laboratory determination of chloride on cleaned surfaces
• ISO 8502-6: Extraction of water-soluble contaminants for analysis (Bresle method)
• ISO 8502-15: Extraction of soluble contaminants for acid extraction analysis
• ISO 12944-8: Development of paint system specifications for corrosion protection of steel structures

By aligning procedures with these standards, organizations ensure consistency, accuracy, and international recognition in their surface preparation and coating quality control processes.

---

Keywords: ISO 8502-5, chloride measurement, steel surface cleanliness, ion detection tube method, surface preparation standard, corrosion protection, field test for chloride, paint application on steel, ISO painting standards, surface contamination assessment.

Standards Content (Sample)

International
Standard
ISO 8502-5
Second edition
Preparation of steel substrates
2025-06
before application of paints and
related products — Tests for the
assessment of surface cleanliness —
Part 5:
Measurement of chloride on steel
surfaces prepared for painting (ion
detection tube method)
Préparation des subjectiles d’acier avant application de peintures
et de produits assimilés — Essais pour apprécier la propreté
d’une surface —
Partie 5: Mesurage des chlorures sur les surfaces d’acier
préparées pour la mise en peinture (méthode du tube détecteur
d’ions)
Reference number
© ISO 2025
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
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus and materials . 2
5.1 Extraction solvent.2
5.2 Chloride ion detection tube .2
5.2.1 Design . .2
5.2.2 Calibration . . .2
5.3 Cutter .2
5.4 Vessel .2
5.5 Gloves .2
6 Procedure . 2
6.1 Extraction of chloride . .2
6.2 Determination of the chloride concentration in the extract solution .3
6.3 Verification test.3
7 Expression of results . 3
8 Test report . 3

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 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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 35, Paints and varnishes, Subcommittee SC 12,
Preparation of steel substrates before application of paints and related products, in collaboration with the
European Committee for Standardization (CEN) Technical Committee CEN/TC 139, Paints and varnishes, in
accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 8502-5:1998), which has been technically
revised.
The main changes are as follows:
— the procedure for washing the test area has been moved to ISO 8502-2 and replaced with the extraction
of chloride as specified in ISO 8502-6 and ISO 8
...

Norme
internationale
ISO 8502-5
Deuxième édition
Préparation des subjectiles d’acier
2025-06
avant application de peintures et
de produits assimilés — Essais
pour apprécier la propreté d’une
surface —
Partie 5:
Mesurage des chlorures sur les
surfaces d’acier préparées pour la
mise en peinture (méthode du tube
détecteur d’ions)
Preparation of steel substrates before application of paints
and related products — Tests for the assessment of surface
cleanliness —
Part 5: Measurement of chloride on steel surfaces prepared for
painting (ion detection tube method)
Numéro de référence
DOCUMENT PROTÉGÉ PAR COPYRIGHT
© ISO 2025
Tous droits réservés. Sauf prescription différente ou nécessité dans le contexte de sa mise en œuvre, aucune partie de cette
publication ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique,
y compris la photocopie, ou la diffusion sur l’internet ou sur un intranet, sans autorisation écrite préalable. Une autorisation peut
être demandée à l’ISO à l’adresse ci-après ou au comité membre de l’ISO dans le pays du demandeur.
ISO copyright office
Case postale 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Genève
Tél.: [phone]
E-mail: [e-mail]
Web: www.iso.org
Publié en Suisse
ii
Sommaire Page
Avant-propos .iv
1 Domaine d’application . 1
2 Références normatives . 1
3 Termes et définitions . 1
4 Principe. 2
5 Appareillage et matériel . 2
5.1 Solvant d’extraction .2
5.2 Tube détecteur d’ions chlorure .2
5.2.1 Conception .2
5.2.2 Étalonnage .2
5.3 Cutter .2
5.4 Récipient . .2
5.5 Gants .2
6 Mode opératoire . 3
6.1 Extraction des chlorures .3
6.2 Détermination de la teneur en chlorures de la solution d’extraction .3
6.3 Essai de contrôle .3
7 Expression des résultats . 3
8 Rapport d’essai . 4

iii
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes nationaux
de normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est en général
confiée aux comités techniques de l'ISO. Chaque comité membre intéressé par une étude a le droit de faire
partie du comité technique créé à cet effet. Les organisations internationales, gouvernementales et non
gouvernementales, en liaison avec l'ISO participent également aux travaux. L'ISO collabore étroitement avec
la Commission électrotechnique internationale (IEC) en ce qui concerne la normalisation électrotechnique.
Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont
décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier, de prendre note des différents
critères d'approbation requis pour les différents types de documents ISO. Le présent document a
été rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2 (voir
www.iso.org/directives).
L’ISO attire l’attention sur le fait que la mise en application du présent document peut entraîner l’utilisation
d’un ou de plusieurs brevets. L’ISO ne prend pas position quant à la preuve, à la validité et à l’applicabilité de
tout droit de brevet revendiqué à cet égard. À la date de publication du présent document, l’ISO n'avait pas
reçu notification qu’un ou plusieurs brevets pouvaient être nécessaires à sa mise en application. Toutefois,
il y a lieu d’avertir les responsables de la mise en application du présent document que des informations
plus récentes sont susceptibles de figurer dans la base de données de brevets, disponible à l'adresse
www.iso.org/brevets. L’ISO ne saurait être tenue pour responsable de ne pas avoir identifié tout ou partie de
tels droits de propriété.
Les appellations commerciales éventuellement mentionnées dans le présent document sont données pour
information, par souci de commodité, à l’intention des utilisateurs et ne sauraient constituer un engagement.
Pour une explication de la nature volontaire des normes, la signification des termes et expressions
spécifiques de l'ISO liés à l'évaluation de la conformité, ou pour toute information au sujet de l'adhésion de
l'ISO aux principes de l’Organisation mondiale du commerce (OMC) concernant les obstacles techniques au
commerce (OTC), voir www.iso.org/avant-propos.
Le présent document a été élaboré par le comité technique ISO/TC 35, Peintures et vernis, sous-comité SC 12,
Préparation de subjectiles d’acier avant application de peintures et de produits assimilés, en collaboration
avec le comité technique CEN/TC 139, Peintures et vernis, du Comité européen de normalisation (CEN),
conformément à l'Accord de coopération technique entre l'ISO et le CEN (Accord de Vienne).
Cette deuxième édition annule et remplace la première édition (ISO 8502-5:1998), qui a fait l’objet d’une
révision technique.
Les principales modifications sont les suivantes:
— transfert du mode opératoire de lavage de la surface d’essai dans l’ISO 8502-2 et remplacement par
l’extraction des chlorures comme spécifié dans l’ISO 8502-6 et l’ISO 8502-15;
— révision de la détermination de la teneur en chlorures de la solution d’extraction;
— modification de la gamme de concentration de la solution d’essai de contrôle;
— révision de la formule d’expression des résultats.
Une liste de toutes les parties de la série ISO 8502 se trouve sur le site Web de l’ISO.
Il convient que l’utilisateur adresse tout retour d’information ou toute question concernant le présent
document à l’organisme national de
...

2025-06
Style Definition
...
Formatted: Bottom: 0.5 cm, Section start: Odd page,
ISO/PRF 8502--5:2025(en)
Header distance from edge: 1.25 cm, Footer distance
from edge: 0 cm, Different first page header
ISO/TC 35/SC 12/WG 2
Formatted: Font: Bold, English (United States)
Formatted: zzCover
Secretariat: BSI
Formatted
...
Date: 2025-04-28
Formatted
...
Formatted
...
Preparation of steel substrates before application of paints and
Formatted
...
related products — Tests for the assessment of surface cleanliness —
— Part 5: Formatted: zzCover
Measurement of chloride on steel surfaces prepared for painting (ion detection tube
Formatted
...
method)
Préparation des subjectiles d’acier avant application de peintures et de produits assimilés — Essais pour
apprécier la propreté d’une surface —
— Partie 5: Mesurage des chlorures sur les surfaces d’acier préparées pour la mise en peinture Formatted: zzCover
(méthode du tube détecteur d’ions)
Formatted
...
PROOF
ISO/PRF DIS 8502-5:2025(en2024(E)
Formatted: Font: 12 pt
Formatted: Header, Space After: 36 pt, Line spacing:
Exactly 12 pt
Formatted: Font: 12 pt
Formatted: Font: 12 pt
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 the internet or an intranet, without prior written
permission. Permission can be requested from either ISO at the address below or ISO’sISO's member
body in the country of the requester.
ISO copyright officeCopyright Office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Formatted: zzCopyright, Don't adjust space between
Latin and Asian text, Don't adjust space between Asian
Phone: + 41 22 749 01 11
text and numbers
Formatted: English (United Kingdom)
E-mail: [e-mail]
Formatted: English (United Kingdom)
Email: [e-mail]
Website: www.iso.orgwww.iso.org
Formatted: zzCopyright, Don't adjust space between
Latin and Asian text, Don't adjust space between Asian
Published in Switzerland.
text and numbers
Formatted: Font: 9 pt
Formatted: Font: 9 pt
Formatted: Font: 10 pt
Formatted: Footer, Space After: 24 pt, Line spacing:
Exactly 12 pt
ii © ISO 2025 2024 – All rights reserved
ii
ISO/PRF 8502-5:2025(en)
Formatted: Font: 12 pt
Formatted: Header, Centered
Formatted: Font: 12 pt
Contents
Formatted: Don't adjust space between Latin and
Asian text, Don't adjust space between Asian text and
Foreword . iv numbers
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus and materials . 2
6 Procedure . 2
7 Expression of results . 3
8 Test report . 3

Foreword . iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus and materials . 2
5.1 Extraction solvent . 2
5.2 Chloride ion detection tube. 2
5.2.1 Design . 2
5.2.2 Calibration . 2
5.3 Cutter . 2
5.4 Vessel . 2
5.5 Gloves . 2
6 Procedure . 3
6.1 Extraction of chloride . 3
6.2 Determination of the chloride concentration in the extract solution . 3
6.3 Verification test . 3
7 Expression of results . 3
8 Test report . 4

Formatted: Font: 9 pt
Formatted: Normal, Centered, Space Before: 18 pt,
Tab stops: 17.2 cm, Right
Formatted: Font: 9 pt
Formatted: Font: 9 pt
Formatted: Normal, Centered, Space After: 24 pt, Tab
stops: 17.2 cm, Right
© ISO 2025 – All rights reserved
iii
ISO/PRF DIS 8502-5:2025(en2024(E)
Formatted: Font: 12 pt
Formatted: Font: 12 pt
Formatted: Font: 12 pt
Foreword
Formatted: Header, Space After: 36 pt, Line spacing:
Exactly 12 pt
ISO (the International Organization for Standardization) is a worldwide federation of national standards
Formatted: Don't adjust space between Latin and
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
Asian text, Don't adjust space between Asian text and
ISO technical committees. Each member body interested in a subject for which a technical committee has been
numbers
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
Formatted: English (United States)
ISO document should be noted. This document was drafted in accordance with the editorial rules of the
Formatted: English (United States)
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Formatted: Don't adjust space between Latin and
ISO draws attention to the possibility that the implementation of this document may involve the use of (a) Asian text, Don't adjust space between Asian text and
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights numbers
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
Formatted: std_publisher
which may be required to implement this document. However, implementers are cautioned that this may not
Formatted: std_docNumber
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents.www.iso.org/patents. ISO shall not be held responsible for identifying any or all such Formatted: std_docPartNumber
patent rights.
Formatted: std_year
Formatted: Don't adjust space between Latin and
Any trade name used in this document is information given for the convenience of users and does not
Asian text, Don't adjust space between Asian text and
constitute an endorsement.
numbers, Tab stops: 0.7 cm, Left + 1.4 cm, Left + 2.1
cm, Left + 2.8 cm, Left + 3.5 cm, Left + 4.2 cm, Left +
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
4.9 cm, Left + 5.6 cm, Left + 6.3 cm, Left + 7 cm, Left
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Formatted: std_publisher
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.htmlwww.iso.org/iso/foreword.html.
Formatted: std_docNumber
Formatted: std_docPartNumber
This document was prepared by Technical Committee ISO/TC 35, Paints and varnishes, Subcommittee SC 12,
Formatted: std_publisher
Preparation of steel substrates before application of paints and related products, in collaboration with the
European Committee for Standardization (CEN) Technical Committee CEN/TC 139, Paints and varnishes, in
Formatted: std_docNumber
accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
Formatted: std_docPartNumber
This second edition cancels and replaces the first edition (ISO 8502-5:1998), which has been technically
Formatted: std_publisher
revised.
Formatted: std_docNumber
Formatted: std_docPartNumber
The main changes are as follows:
Formatted: Don't adjust space between Latin and
— the procedure for washing the test area has been moved to ISO 8502-2 and replaced with the extraction
Asian text, Don't adjust space between Asian text and
of chloride as specified in ISO 8502-6 and ISO 8502-15;
numbers
Formatted: std_publisher
— the determination of the chloride concentration in the extract solution has been revised;
Formatted: std_docNumber
— the range in the verification test solution has been changed;
Formatted: std_docPartNumber
Formatted: Font: 9 pt
— the formula for the expression of results has been revised.
Formatted: Font: 9 pt
A list of all parts in the ISO 8502 series can be found on the ISO website.
Formatted: Font: 10 pt
Formatted: Footer, Space After: 24 pt, Line spacing:
Exactly 12 pt
iv © ISO 2025 2024 – All rights reserved
iv
ISO/PRF 8502-5:2025(en)
Formatted: Font: 12 pt
Formatted: Header, Centered
Formatted: Font: 12 pt
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. Formatted: English (United States)
Formatted: English (United States)

Field Code Changed
Formatted: Font: 9 pt
Formatted: Normal, Centered, Space Before: 18 pt,
Tab stops: 17.2 cm, Right
Formatted: Font: 9 pt
Formatted: Font: 9 pt
Formatted: Normal, Centered, Space After: 24 pt, Tab
stops: 17.2 cm, Right
© ISO 2025 – All rights reserved
v
International Standard ISO 8502-5:2025(en)

P
...