oSIST prEN ISO 8502-15:2026

• Abstract:

  This document specifies a method of extracting, for analysis, acid soluble contaminants from a surface by use of flexible cells in the form of adhesive patches or sleeves which can be attached to any surface, regardless of its shape (flat or curved) and its orientation (facing in any direction, including downwards).; The described method is suitable for use in the field to determine the presence of acid soluble contaminants before painting or a similar treatment.; This document does not cover the subsequent analysis of the contaminants that have been dissolved off. Methods of analysis suitable for field use are described in other parts of ISO 8502 such as ISO 8502-5.; This document is similar in procedure to, but not equal to, ISO 8502-6. The main difference is the solvent used and the subsequent analysis that can be performed on the extraction solution.

• Status: Not Published
• Public Enquiry End Date: 01-Nov-2026
• ICS: 25.220.10 - Surface preparation
• ICS: 87.020 - Paint coating processes
• Technical Committee: IBLP - Paints and varnishes
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 09-Sep-2026
• Due Date: 27-Jan-2027
• Ref Project: prEN ISO 8502-15 - Preparation of steel substrates before application of paints and related products - Tests for the assessment of surface cleanliness - Part 15: Extraction of soluble contaminants for analysis by acid extraction (ISO/DIS 8502‑15:2026)

• Revises: SIST EN ISO 8502-15:2025 - Preparation of steel substrates before application of paints and related products - Tests for the assessment of surface cleanliness - Part 15: Extraction of soluble contaminants for analysis by acid extraction (ISO 8502-15:2020)
• Effective Date: 01-Oct-2026

oSIST prEN ISO 8502-15:2026 is a CEN draft in the ISO 8502 series for preparing steel substrates before application of paints and related products. It specifies a field method for extracting acid soluble contaminants from steel surfaces using flexible adhesive patches or sleeves, so the extract can be analysed before painting or a similar treatment.

What does oSIST prEN ISO 8502-15:2026 specify?

oSIST prEN ISO 8502-15:2026 specifies how to take an extract from a steel surface with flexible cells and a mildly acidic solvent. The method is intended for field use on flat or curved surfaces, in any orientation, including downward-facing surfaces.

The document is organized into scope, normative references, terms and definitions, principle, apparatus and materials, procedure, analysis, test report, and a normative annex on leak testing. The scope also makes clear that the document covers extraction only, not the later chemical analysis of the extract.

Annex	What it covers
Annex A	Normative leak test for type testing of adhesive cells, including patches and sleeves

What are the key requirements of oSIST prEN ISO 8502-15:2026?

oSIST prEN ISO 8502-15:2026 focuses on extracting contaminants without losing solvent, because the quality of the extract determines the reliability of the later analysis. In practice, users need suitable cells, a compatible solvent, careful handling, and a test report that records the extraction conditions.

Extraction principle and cell types

Clause 4 describes two cell types: an adhesive patch with a central compartment, and a flexible sleeve. The patch uses injection and withdrawal of the acid, while the sleeve can be used either by injection or by pre-filling. This matters because the choice affects how the surface is wetted and how practical the method is on the job site.

Apparatus, materials, and solvent

Clause 5 specifies an ageing-resistant flexible adhesive cell, a reusable syringe, a contact thermometer, and a mildly acidic solvent. The solvent is required to have pH 3.6 ± 0.3 and to avoid ions of interest or acids that interfere with later analysis. For readers, this means the extraction liquid must be chosen to suit the contaminant being measured, not just any acid.

The document also gives standard cell sizes, including patch A-1250 and sleeve S-1000. The adhesive cell must be leak-tight, and Annex A provides the type-test for checking that property.

Surface selection and extraction procedure

Clause 6.1 directs users to select representative test areas, and to focus on pitted zones, metal loss, and welds where salts tend to accumulate. That is important in practice because contamination is often localized rather than evenly spread.

Clauses 6.2 and 6.3 set out the extraction steps for patch/sleeve injection and for sleeve pre-filling. The procedure requires full wetting of the test area, agitation during contact, and careful recovery of the solvent. If solvent is lost, the resulting solution is rejected.

Blank testing, temperature, and analysis

Clause 6.4 requires blank tests for each batch of cells, and additional blank testing when background interference is significant and cannot be eliminated. Clause 6.3.7 requires recording the steel surface temperature, which must be above 0 °C.

Clause 7 leaves the analytical method to be agreed between the interested parties and points to chloride measurement by ISO 8502-5 as an example. For users, this means oSIST prEN ISO 8502-15:2026 is the sampling step, not the full measurement method.

Type testing of the cells

Annex A gives the leak test for adhesive patches and sleeves. It uses water, a clean steel plate, and a timed pressure test to verify leak-tightness. This matters because a leaking cell can understate contamination and make results unreliable.

Who uses oSIST prEN ISO 8502-15:2026?

oSIST prEN ISO 8502-15:2026 is used by coating inspectors, corrosion engineers, paint applicators, quality managers, and testing laboratories working with steel surface preparation. It is relevant when a buyer, contractor, or inspector needs to check for salt or other acid soluble contamination before painting, especially on structures with pitting, welds, or difficult surface geometry.

What changed in oSIST prEN ISO 8502-15:2026 from the previous edition?

oSIST prEN ISO 8502-15:2026 replaces ISO 8502-15:2020. The document states that Table 1 was revised and that Clauses 5 and 6 were revised.

Which standards are used with oSIST prEN ISO 8502-15:2026?

oSIST prEN ISO 8502-15:2026 refers to several related standards that support sampling, analysis, and laboratory competence.

• ISO 8502-5 - gives a chloride measurement method using ion detection tubes for steel surfaces prepared for painting.
• ISO 8502-6 - gives the Bresle method for extracting water soluble contaminants.
• ISO/IEC 17025 - sets competence requirements for testing and calibration laboratories, which matters for leak testing and other laboratory work.
• ISO 8501, ISO 8503, and ISO 8504 - frame the wider ISO system for visual cleanliness, surface roughness, and surface preparation methods mentioned in the introduction.

What does the oSIST prEN ISO 8502-15:2026 document contain?

The document contains a defined field extraction method, a materials list, step-by-step procedures, and reporting requirements. It also includes figures showing the patch, sleeve, syringe, injection, retrieval, transfer to a vessel, and sleeve placement on metal.

Table 1 gives the standard cell sizes and the related compartment areas, while Annex A gives the leak test set-up and acceptance condition for type testing. The test report clause identifies the information that must be recorded, including the solvent, volumes used, contact time, temperature, cell type and size, batch number, and test date.

The annex and figures are practical rather than descriptive: they support selection of equipment, execution of the extraction, and verification that the cell performs without leakage.

SLOVENSKI STANDARD
01-oktober-2026
Priprava jeklenih podlag pred nanašanjem barv in sorodnih premazov - Preskusi
za ocenjevanje čistosti površine - 15. del: Ekstrakcija topnih nečistoč s kislino za
nadaljnjo analizo (ISO/DIS 8502-15:2026)
Preparation of steel substrates before application of paints and related products - Tests
for the assessment of surface cleanliness - Part 15: Extraction of soluble contaminants
for analysis by acid extraction (ISO/DIS 8502-15:2026)
Vorbereitung von Stahloberflächen vor dem Auftragen von Beschichtungsstoffen -
Prüfungen zum Beurteilen der Oberflächenreinheit - Teil 15: Extraktion von löslichen
Verunreinigungen zur Analyse durch Säureextraktion (ISO/DIS 8502-15:2026)
Préparation des subjectiles d’acier avant application de peintures et de produits
assimilés - Essais pour apprécier la propreté d’une surface - Partie 15: Extraction des
contaminants solubles en vue de l’analyse par extraction à l’acide (ISO/DIS 8502-
15:2026)
Ta slovenski standard je istoveten z: prEN ISO 8502-15
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 8502-15
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 15:
Extraction of soluble contaminants
for analysis by acid extraction
Préparation des subjectiles d’acier avant application de peintures
et de produits assimilés — Essais pour apprécier la propreté
d’une surface —
Partie 15: Extraction des contaminants solubles en vue de
l’analyse par extraction à l’acide
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 8502-15:2026(en)
DRAFT
ISO/DIS 8502-15:2026(en)
International
Standard
ISO/DIS 8502-15
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 15:
Extraction of soluble contaminants
for analysis by acid extraction
Préparation des subjectiles d’acier avant application de peintures
et de produits assimilés — Essais pour apprécier la propreté
d’une surface —
Partie 15: Extraction des contaminants solubles en vue de
l’analyse par extraction à l’acide
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: [phone]
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 8502-15:2026(en)
ii
ISO/DIS 8502-15:2026(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus and materials . 2
5.1 Adhesive cell .2
5.2 Reusable syringe .2
5.3 Solvent .2
5.4 Contact thermometer .3
6 Procedure . 3
6.1 Selection of test surface .3
6.2 Extraction by patch or sleeve by injection .3
6.3 Extraction by sleeve by pre-filling .4
6.4 Blank test .4
7 Analysis . . 4
8 Test report . 5
Annex A (normative) Leak test for type testing of adhesive cells (patches and sleeves) . 8
Bibliography .10

iii
ISO/DIS 8502-15:2026(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.
This second edition cancels and replaces the first edition (ISO 8502-15:2020), which has been technically
revised. The main changes compared to the previous edition are as follows:
— Table 1 has been revised;
— Clause 5 and Clause 6 have been revised.
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 8502-15:2026(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 profile.
The ISO 8501, ISO 8502 and ISO 8503 series have been prepared to provide methods of assessing these
factors, while the ISO 8504 series 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 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 will be exposed
and for the protective coating system to be used;
— within the capability of the cleaning procedure specified.
The four series of international standards referred to above deal with the following aspects of preparation
of steel substrates:
— visual assessment of surface cleanliness (see ISO 8501 series);
— tests for the assessment of surface cleanliness (see ISO 8502 series);
— surface roughness characteristics of blast-cleaned steel substrates (see ISO 8503 series);
— surface preparation methods (see ISO 8504 series).
Each of these series of international standards is in turn divided into separate parts.
This document, along with the other parts of the ISO 8502 series, specifies tests for the assessment of
surface cleanliness. In connection with such tests, there are several methods for the extraction, for analysis,
of soluble contaminants on surfaces to be painted. Some of these methods are based on the swabbing of
comparatively large test surfaces. This technique provides average values of the contamination present, but
it might conceal localized concentrations of contaminants. Swabbing might not ensure sufficient penetration
to dissolve all of the deep-seated contamination such as ferrous salts. Furthermore, the solvent used affects
the dissolution rate and what contaminants are dissolved. This document covers sampling with a weak acid
as solvent.
There are other methods, however, which use small cells for the liquid to remove and collect the surface
contaminants. The cells (rigid or flexible) are attached to test surfaces where soluble contaminants could
be expected, for example where pitting has occurred. This technique usually provides more accurate point
values of the contamination present.

v
DRAFT International Standard ISO/DIS 8502-15:2026(en)
Preparation of steel substrates before application of paints
and related products — Tests for the assessment of surface
cleanliness —
Part 15:
Extraction of soluble contaminants for analysis by acid
extraction
1 Scope
This document specifies a method of extracting, for analysis, acid soluble contaminants from a surface by use
of flexible cells in the form of adhesive patches or sleeves which can be attached to any surface, regardless of
its shape (flat or curved) and its orientation (facing in any direction, including downwards).
The described method is suitable for use in the field to determine the presence of acid soluble contaminants
before painting or a similar treatment.
This document does not cover the subsequent analysis of the contaminants that have been dissolved off.
M
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