kSIST FprEN ISO 787-9:2026

• Abstract:

  This document specifies a general method of test for determining the pH value of an aqueous suspension of a sample of pigment or extender.

• Status: Not Published
• Public Enquiry End Date: 01-Jun-2026
• ICS: 87.060.10 - Pigments and extenders
• Technical Committee: PIP - Pigments and extenders
• Current Stage: 5020 - Formal vote (FV) (Adopted Project)
• Start Date: 02-Nov-2026
• Due Date: 21-Dec-2026
• Ref Project: FprEN ISO 787-9 - General methods of test for pigments and extenders - Part 9: Determination of pH value of an aqueous suspension (ISO/FDIS 787-9:2026)

• Revises: SIST EN ISO 787-9:2019 - General methods of test for pigments and extenders - Part 9: Determination of pH value of an aqueous suspension (ISO 787-9:2019)
• Effective Date: 01-May-2026

kSIST FprEN ISO 787-9:2026 is a general test method for pigments and extenders published by SIST as the Slovenian adoption of the ISO draft on pH determination. It specifies how to measure the pH value of an aqueous suspension of a pigment or extender sample, so laboratories can compare results on the same basis.

What does kSIST FprEN ISO 787-9:2026 specify?

kSIST FprEN ISO 787-9:2026 specifies a laboratory method for determining the pH value of an aqueous suspension made from a sample of pigment or extender. It is a test method document, not a product specification.

The document is organized into:

• Scope
• Normative references
• Terms and definitions
• Reagents
• Apparatus
• Sampling
• Procedure
• Expression of results
• Test report

That structure matters in practice because it shows the full workflow: choose the right sample, prepare the suspension, measure pH, then report the result in a consistent way.

What are the key requirements of kSIST FprEN ISO 787-9:2026?

The method depends on controlled water quality, careful sample preparation and calibrated pH measurement. The main points in Clauses 4 to 9 are the practical steps that determine whether results are comparable.

Reagents and measuring setup

Clause 4 requires distilled or demineralized water of at least grade 3 from ISO 3696, with a pH between 5,0 and 7,5, and protected from atmospheric carbon dioxide. Clause 4 also gives an optional ion intensity regulating solution, 0,1 % KCl, prepared with that water. In practice, this reduces variation in the suspension and helps make readings more stable.

Clause 5 requires a chemically resistant glass container, a pH measuring device readable to 0,1 unit and calibrated at the test temperature, and a balance with suitable error limit. This means the result depends not only on the sample but also on clean, suitable equipment and calibration at the right temperature.

Sampling and suspension preparation

Clause 6 requires a representative sample taken in accordance with ISO 15528. That matters because pH can vary if the sample is not representative of the batch.

Clause 7 requires the test to be carried out at room temperature and the sample to be made into a 5 % to 10 % mass fraction suspension with water or the ion intensity regulating solution. The suspension is then shaken, rolled or stirred vigorously, left for 5 min, and measured to the nearest 0,1 unit. The document also allows filtering the suspension before measurement, if needed.

Wetting agent and reporting

Clause 7 allows a wetting agent when the product does not disperse easily in water. Pure ethanol or methanol may be used up to 10 % by volume of the suspension, but the minimum quantity should be used and the neutrality of the wetting agent checked by a blank determination. The water volume is adjusted so the original suspension concentration stays the same. In practice, this keeps difficult-to-disperse pigments measurable without changing the meaning of the result.

Clause 8 requires the result to be reported to the nearest 0,1 unit. Clause 9 requires the report to include the product identification, the reference to ISO 787-9, the suspension concentration and liquid used, any filtration method, any wetting agent used, the result, the test temperature, deviations, anomalies and the test date.

What terms does kSIST FprEN ISO 787-9:2026 use?

The document uses the terminology of ISO 18451-1 for pigments, dyestuffs and extenders. A few terms are especially important for reading and applying the method:

• pH value - the measured acidity or alkalinity of the aqueous suspension.
• Aqueous suspension - a mix of the sample in water, or in the ion intensity regulating solution, prepared for measurement.
• Ion intensity regulating solution - the optional 0,1 % KCl solution used to improve measurement consistency.
• Wetting agent - an additive used when the sample does not disperse easily in water.
• Representative sample - a sample taken so it reflects the product being tested.
• Mass fraction - the concentration basis used for the 5 % to 10 % suspension.

Who uses kSIST FprEN ISO 787-9:2026?

kSIST FprEN ISO 787-9:2026 is used by laboratories testing pigments and extenders, including quality control and quality assurance teams in manufacturers’ plants. It is also relevant to buyers, specification writers and third-party test labs that need a common way to compare pH results on pigment or extender suspensions.

What changed in kSIST FprEN ISO 787-9:2026 from the previous edition?

kSIST FprEN ISO 787-9:2026 replaces ISO 787-9:2019 and is described as a technical revision. The stated changes are:

• updated normative references
• revised wording for distilled or demineralized water in 4.1
• replacement of “buffer solution” with “ion intensity regulating solution” in 4.2
• changed quantity of added wetting agent in Clause 7
• updated information required in the test report in Clause 9

Which standards are used with kSIST FprEN ISO 787-9:2026?

kSIST FprEN ISO 787-9:2026 refers to three standards that support the method:

• ISO 3696 - specifies the quality of the water used for the suspension.
• ISO 15528 - gives the sampling method for obtaining a representative test sample.
• ISO 18451-1 - provides the terminology used for pigments, dyestuffs and extenders.

What does the kSIST FprEN ISO 787-9:2026 document contain?

The document contains the full test method for pH measurement of pigment and extender suspensions, including reagent requirements, apparatus, sampling, procedure, result expression and reporting. It also gives the practical details needed to run the test consistently, such as suspension concentration, standing time, measurement precision and optional use of a wetting agent.

It does not present product specifications or acceptance limits. Its value is in the test setup and reporting rules that let different laboratories obtain comparable pH results for the same material.

SLOVENSKI STANDARD
oSIST prEN ISO 787-9:2026
01-maj-2026
Splošne preskusne metode za pigmente in polnila - 9. del: Določanje pH-vrednosti
vodne suspenzije (ISO/DIS 787-9:2026)
General methods of test for pigments and extenders - Part 9: Determination of pH value
of an aqueous suspension (ISO/DIS 787-9:2026)
Allgemeine Prüfverfahren für Pigmente und Füllstoffe - Teil 9: Bestimmung des pH-
Wertes einer wässrigen Suspension (ISO/DIS 787-9:2026)
Méthodes générales d'essai des pigments et matières de charge - Partie 9:
Détermination du pH d'une suspension aqueuse (ISO/DIS 787-9:2026)
Ta slovenski standard je istoveten z: prEN ISO 787-9
ICS:
87.060.10 Pigmenti in polnila Pigments and extenders
oSIST prEN ISO 787-9:2026 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN ISO 787-9:2026
oSIST prEN ISO 787-9:2026
DRAFT
International
Standard
ISO/DIS 787-9
ISO/TC 256
General methods of test for
Secretariat: DIN
pigments and extenders —
Voting begins on:
Part 9: 2026-03-24
Determination of pH value of an
Voting terminates on:
2026-06-16
aqueous suspension
Méthodes générales d'essai des pigments et matières de charge —
Partie 9: Détermination du pH d'une suspension aqueuse
ICS: 87.060.10
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 is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
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USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
BE CONSIDERED IN THE LIGHT OF THEIR
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Reference number
ISO/DIS 787-9:2026(en)
oSIST prEN ISO 787-9:2026
DRAFT
ISO/DIS 787-9:2026(en)
International
Standard
ISO/DIS 787-9
ISO/TC 256
General methods of test for
Secretariat: DIN
pigments and extenders —
Voting begins on:
Part 9:
2026-03-24
Determination of pH value of an
Voting terminates on:
2026-06-16
aqueous suspension
Méthodes générales d'essai des pigments et matières de charge —
Partie 9: Détermination du pH d'une suspension aqueuse
ICS: 87.060.10
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 is circulated as received from the committee 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
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Published in Switzerland Reference number
ISO/DIS 787-9:2026(en)
ii
oSIST prEN ISO 787-9:2026
ISO/DIS 787-9:2026(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Reagents . 1
5 Apparatus . 2
6 Sampling . 2
7 Procedure . 2
8 Expression of results . 2
9 Test report . 2

iii
oSIST prEN ISO 787-9:2026
ISO/DIS 787-9:2026(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 a
...