ISO 22197-2:2019

INTERNATIONAL ISO
STANDARD 22197-2
Second edition
2019-10
Fine ceramics (advanced ceramics,
advanced technical ceramics) —
Test method for air-purification
performance of semiconducting
photocatalytic materials —
Part 2:
Removal of acetaldehyde
Céramiques techniques — Méthodes d'essai relatives à la performance
des matériaux photocatalytiques semi-conducteurs pour la
purification de l'air —
Partie 2: Élimination de l'acétaldéhyde
Reference number
©
ISO 2019
© ISO 2019
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Published in Switzerland
ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 2
5 Principle . 3
6 Apparatus . 3
6.1 Test equipment . 3
6.2 Test gas supply . 4
6.3 Photoreactor . 5
6.4 Light source . 6
6.5 Analytical system for acetaldehyde . 6
6.6 Analytical system for CO . 7
7 Test piece . 7
8 Procedure. 7
8.1 General aspects . 7
8.2 Pretreatment of test piece . 8
8.3 Preparation for the test . 8
8.4 Pretest . 9
8.5 Test of acetaldehyde removal and CO conversion . 9
8.6 Test of acetaldehyde removal (when the CO concentration cannot be measured) .10
9 Calculation .11
9.1 Calculation method .11
9.2 Removal percentage and removed quantity of acetaldehyde .11
9.3 Conversion to CO .11
10 Test method for test pieces with lower performance .12
11 Test report .13
Annex A (informative) Results of round-robin test .14
Bibliography .16
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
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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
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.org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 206, Fine ceramics.
This second edition cancels and replaces the first edition (ISO 22197-2:2011), which has been technically
revised. The main changes compared to the previous edition are as follows:
— deletion of reference to ISO 2718 (withdrawn) from Clause 2 and 6.5;
— deletion of ISO 4677-1 (withdrawn) from Clause 2 and 8.3.1;
— change of gas flow measurement from dry-gas basis to wet-gas basis in 6.2;
— change of tolerance on dimensions of test piece in Clause 7;
— addition of procedures for removing water-soluble contaminants (8.2);
— addition of criterion for acceptable adsorption of acetaldehyde (9.2).
A list of all parts in the ISO 22197 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

INTERNATIONAL STANDARD ISO 22197-2:2019(E)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Test method for air-purification performance
of semiconducting photocatalytic materials —
Part 2:
Removal of acetaldehyde
1 Scope
This document specifies a test method for the determination of the air-purification performance of
materials that contain a photocatalyst or have photocatalytic films, usually made from semiconducting
metal oxides, such as titanium dioxide or other ceramic materials, by continuous exposure of a test
piece to the model air pollutant under irradiation with ultraviolet light (UV-A).
This document is intended for use with different kinds of materials, such as construction materials in
flat sheet, board or plate shape, that are the basic forms of materials for various applications.
This document also applies to structured filter materials including honeycomb-form, woven and non-
woven fabrics, and to plastic or paper materials if they contain ceramic microcrystals and composites.
This document does not apply to powder or granular photocatalytic materials.
This test method is usually applicable to photocatalytic materials produced for air purification.
This method is not suitable for the determination of other performance attributes of photocatalytic
materials, i.e. decomposition of water contaminants, self-cleaning, antifogging and antibacterial
actions. It concerns the removal of acetaldehyde.
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 4224, Ambient air — Determination of carbon monoxide — Non-dispersive infrared spectrometric method
ISO 10677, Fine ceramics (advanced ceramics, advanced technical ceramics) — Ultraviolet light source for
testing semiconducting photocatalytic materials
ISO 16000-3, Indoor air — Part 3: Determination of formaldehyde and other carbonyl compounds in indoor
air and test chamber air — Active sampling method
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
ISO 80000-1:2009, Quantities and units — Part 1: General
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
photocatalyst
substance that performs one or more functions based on oxidization and reduction reactions under
photoirradiation, including decomposition and removal of air and water contaminants, deodorization,
and antibacterial, self-cleaning and antifogging actions
3.2
photocatalytic materials
materials in which or on which the photocatalyst is added by, for example, coating, impregnation or mixing
Note 1 to entry: Such photocatalytic materials are intended primarily for use as building and road construction
materials to obtain the functions described in 3.1.
3.3
zero-calibration gas
air that does not contain pollutants (i.e. in which common pollutants are below 0,01 µl/l and carbon
dioxide is below 0,1 µl/l)
Note 1 to entry: The zero-calibration gas is prepared from indoor air using a laboratory air-purification system,
or supplied as synthetic air in a gas cylinder.
3.4
standard gas
diluted gas of known concentration supplied in cylinders and certified by an accredited laboratory
3.5
test gas
mixture of air and pollutant(s) of known concentration prepared from a standard gas or a zero-
calibration gas, to be used for the performance test of a photocatalytic material
3.6
dark condition
test condition with no light irradiation by the light source for testing and room lighting
4 Symbols
For the purposes of this document, the following symbols apply.
f air-flow rate converted into that at the standard state (0 °C and 101,3 kPa) (l/min)
ϕ volume fraction of acetaldehyde at the reactor exit (µl/l)
A
ϕ acetaldehyde volume fraction at the reactor exit under dark conditions (µl/l)
AD
ϕ supply volume fraction of acetaldehyde (µl/l)
A0
carbon dioxide (CO ) volume fraction generated by UV irradiation (µl/l)
φ
CO
CO volume fraction at the reactor exit under UV irradiation (µl/l)
φ
CO ,L
CO volume fraction at the reactor exit under dark conditions (µl/l)
φ
CO ,D
CO volume fraction in the dark
...