prEN ISO 8502-9
(Main)Preparation of steel substrates before application of paints and related products - Tests for the assessment of surface cleanliness - Part 9: Field method for the conductometric determination of water-soluble salts (ISO/DIS 8502‑9:2026)
General Information
- Abstract
This document specifies a field method for the assessment of the surface density of various water-soluble salts on steel surfaces, before and/or after surface preparation, by conductometric determination. The individual surface densities of the salt composition like chlorides, sulphates, sodium, etc, cannot be determined by this method.
This method assesses only contaminants that forms an electrolyte (ions) when in contact with water. These represent the greater part of the contaminants.
- Status
- Not Published
- Publication Date
- 23-Mar-2028
- Technical Committee
- CEN/TC 139 - Paints and varnishes
- Current Stage
- 4020 - Submission to enquiry - Enquiry
- Start Date
- 03-Sep-2026
- Completion Date
- 03-Sep-2026
Overview
prEN ISO 8502-9:2026 provides an internationally recognized method for assessing the cleanliness of steel surfaces by measuring the surface density of water-soluble salts through a conductometric field method. Developed by CEN in collaboration with ISO (ISO/DIS 8502-9:2026), this standard is part of a broader series addressing preparation and evaluation of steel substrates before coatings are applied.
Water-soluble salts, such as chlorides and sulphates, can significantly impact the adhesion, durability, and protective performance of paints and related products. This standard outlines a practical, field-based approach to quantitatively determine the total level of these ionic contaminants, which is essential for ensuring optimal surface preparation and long-lasting coating systems.
Key Topics
- Surface Cleanliness Assessment: Specifies a conductometric test method for evaluating the total amount of water-soluble salts present on steel surfaces, before or after surface preparation.
- Non-Specific Ion Measurement: The process measures total electrolyte content (in mg/m²) but does not differentiate between individual ions such as chloride, sulphate, or sodium.
- Field Method: Designed for use on-site, the method involves extracting salts from steel surfaces using adhesive cells (as per ISO 8502-6), dissolving them in purified water, and measuring solution conductivity.
- Reliable Test Conditions: Emphasizes sample consistency through calibration, use of standardized extraction areas, and accounting for temperature and test equipment accuracy.
- Reporting Requirements: Specifies essential data for test reporting, including equipment details, extraction parameters, environmental conditions, and test results.
Applications
prEN ISO 8502-9 serves a critical function in multiple industries where steel surface preparation and coating quality are paramount:
- Protective Coatings & Anti-corrosion: Ensures that steel substrates are sufficiently free of water-soluble salts, reducing the risk of premature coating failure, blistering, or corrosion beneath the protective layer.
- Surface Preparation Verification: Used by inspectors and contractors during or after processes such as blast cleaning or washing to verify that contaminants have been removed to acceptable levels before paint or coating application.
- Field Quality Control: Enables practical, on-site assessment of surface cleanliness, supporting project documentation and compliance with quality assurance requirements.
- Industrial Sectors: Applicable across marine, oil and gas, construction, infrastructure, and manufacturing sectors where steel surfaces require high-integrity coatings for durability and safety.
Related Standards
prEN ISO 8502-9 forms part of an integrated family of standards for steel surface preparation and evaluation. Related standards include:
- ISO 8501: Visual assessment of surface cleanliness.
- ISO 8502 (Other Parts): Additional test methods for cleanliness assessment, including specific procedures for dust, oil, grease, and particulate contamination.
- ISO 8503: Surface roughness characteristics of blast-cleaned steel substrates.
- ISO 8504: Surface preparation methods and guidance on achieving desired cleanliness and profile.
These standards, when implemented collectively, help ensure steel substrates are effectively prepared and assessed prior to the application of paints and coatings, maximizing both the immediate performance and the lifecycle durability of protective systems.
Keywords: prEN ISO 8502-9, ISO 8502-9, conductometric determination, water-soluble salts, steel surface preparation, field method, surface cleanliness, paints and coatings, chloride contamination, anti-corrosion, quality control, industrial surface testing, CEN standard.
Relations
- Effective Date
- 09-Jul-2025
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Frequently Asked Questions
prEN ISO 8502-9 is a draft published by the European Committee for Standardization (CEN). Its full title is "Preparation of steel substrates before application of paints and related products - Tests for the assessment of surface cleanliness - Part 9: Field method for the conductometric determination of water-soluble salts (ISO/DIS 8502‑9:2026)". This standard covers: This document specifies a field method for the assessment of the surface density of various water-soluble salts on steel surfaces, before and/or after surface preparation, by conductometric determination. The individual surface densities of the salt composition like chlorides, sulphates, sodium, etc, cannot be determined by this method. This method assesses only contaminants that forms an electrolyte (ions) when in contact with water. These represent the greater part of the contaminants.
This document specifies a field method for the assessment of the surface density of various water-soluble salts on steel surfaces, before and/or after surface preparation, by conductometric determination. The individual surface densities of the salt composition like chlorides, sulphates, sodium, etc, cannot be determined by this method. This method assesses only contaminants that forms an electrolyte (ions) when in contact with water. These represent the greater part of the contaminants.
prEN ISO 8502-9 is classified under the following ICS (International Classification for Standards) categories: 25.220.10 - Surface preparation. The ICS classification helps identify the subject area and facilitates finding related standards.
prEN ISO 8502-9 has the following relationships with other standards: It is inter standard links to EN ISO 8502-9:2020. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
prEN ISO 8502-9 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-oktober-2026
Priprava jeklenih podlag pred nanašanjem barv in sorodnih premazov - Preskusi
za ocenjevanje čistosti površine - 9. del: Terenska metoda za konduktometrijsko
določanje soli, topnih v vodi (ISO/DIS 8502-9:2026)
Preparation of steel substrates before application of paints and related products - Tests
for the assessment of surface cleanliness - Part 9: Field method for the conductometric
determination of water-soluble salts (ISO/DIS 8502-9:2026)
Vorbereitung von Stahloberflächen vor dem Auftragen von Beschichtungsstoffen und
verwandten Produkten - Prüfungen zur Beurteilung der Oberflächenreinheit - Teil 9:
Feldverfahren zur konduktometrischen Bestimmung von wasserlöslichen Salzen
(ISO/DIS 8502-9:2026)
Préparation des subjectiles d'acier avant application de peintures et de produits
assimilés - Essais pour apprécier la propreté d'une surface - Partie 9: Méthode in situ
pour la détermination des sels solubles dans l'eau par conductimétrie (ISO/DIS 8502-
9:2026)
Ta slovenski standard je istoveten z: prEN ISO 8502-9
ICS:
25.220.10 Priprava površine Surface preparation
87.020 Postopki za nanašanje Paint coating processes
barvnih premazov
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
International
Standard
ISO/DIS 8502-9
ISO/TC 35/SC 12
Preparation of steel substrates
Secretariat: BSI
before application of paints and
Voting begins on:
related products — Tests for the
2026-08-31
assessment of surface cleanliness —
Voting terminates on:
2026-11-23
Part 9:
Field method for the
conductometric determination of
water-soluble salts
Préparation des subjectiles d'acier avant application de peintures
et de produits assimilés — Essais pour apprécier la propreté
d'une surface —
Partie 9: Méthode in situ pour la détermination des sels solubles
dans l'eau par conductimétrie
ICS: 25.220.10
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document has not been edited by the ISO Central Secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Reference number
ISO/DIS 8502-9:2026(en)
DRAFT
ISO/DIS 8502-9:2026(en)
International
Standard
ISO/DIS 8502-9
ISO/TC 35/SC 12
Preparation of steel substrates
Secretariat: BSI
before application of paints and
Voting begins on:
related products — Tests for the
2026-08-31
assessment of surface cleanliness —
Voting terminates on:
2026-11-23
Part 9:
Field method for the
conductometric determination of
water-soluble salts
Préparation des subjectiles d'acier avant application de peintures
et de produits assimilés — Essais pour apprécier la propreté
d'une surface —
Partie 9: Méthode in situ pour la détermination des sels solubles
dans l'eau par conductimétrie
ICS: 25.220.10
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document has not been edited by the ISO Central Secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2026
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
ISO copyright office
RECIPIENTS OF THIS DRAFT ARE INVITED
CP 401 • Ch. de Blandonnet 8
TO SUBMIT, WITH THEIR COMMENTS,
CH-1214 Vernier, Geneva
NOTIFICATION OF ANY RELEVANT PATENT
Phone: +41 22 749 01 11
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 8502-9:2026(en)
ii
ISO/DIS 8502-9:2026(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus and materials . 1
5.1 Conductometer .1
5.2 Beaker.2
5.3 Equipment for sampling .2
5.4 Syringe .2
5.5 Solvent .2
6 Procedure . 2
6.1 Calibration .2
6.2 Preparation of water and equipment blank test .2
6.3 Sampling of salts from the steel surface .3
6.4 Conductometric measurement .3
7 Calculations . 3
7.1 Calculation of corrected volume .3
7.2 Calculation of total amount of salt on the surface .3
7.3 Examples: Standard patch A-1250 and flexible sleeve S-1000 acc. to ISO 8502-6 .4
8 Accuracy . 5
9 Test report . 6
Bibliography . 7
iii
ISO/DIS 8502-9:2026(en)
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 any patent
rights identified during the development of the document will be in the Introduction and/or on the ISO list of
patent declarations received (see www.iso.org/patents).
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 thirdedition cancels and replaces the second edition (ISO 8502-9:2020), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— the introduction has been revised;
— addition of new Annex A, Evaluation of results.
A list of all parts in the ISO 8502 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/DIS 8502-9:2026(en)
Introduction
The performance of protective coatings of paint and related products applied to steel is significantly
affected by the state of the steel surface immediately prior to painting. The principal factors that are known
to influence this performance are:
a) the presence of rust and mill scale;
b) the presence of surface contaminants, including salts, dust, oils and greases;
c) the surface profiles.
ISO 8501, ISO 8502 and ISO 8503 have been prepared to provide methods of assessing these factors, while
ISO 8504 provides guidance on the preparation methods that are available for cleaning steel substrates,
indicating the capabilities of each in attaining specified levels of cleanliness.
These International Standards do not contain recommendations for the protective coating systems to be
applied to the steel surface. Neither do they contain recommendations for the surface quality requirements
for specific situations even though surface quality can have a direct influence on the choice of protective
coating to be applied and on its performance. Such recommendations are found in other documents such as
national standards and codes of practice. It is be necessary for the users of these International Standards to
ensure that the qualities specified are:
— compatible and appropriate both for the environmental conditions to which the steel is exposed and for
the protective coating system to be used, and
— within the capability of the cleaning procedure specified.
The four International Standards referred to above deal with the following aspects of preparation of steel
substrates before application of paints and related products:
— ISO 8501, Visual assessment of surface cleanliness;
— ISO 8502, Tests for the assessment of surface cleanliness;
— ISO 8503, Surface roughness characteristics of blast-cleaned steel substrates;
— ISO 8504, Surface preparation methods.
Each of these International Standards is in turn divided into separate parts.
This document describes a field method for the assessment of the total amount of water-soluble salts by
conductometric determination, the salts being reported as one value. Conductivity can be caused by multiple
salts. These can include both corrosion-promoting salts such as chlorides
...



