ISO 17094:2014

INTERNATIONAL ISO
STANDARD 17094
First edition
2014-05-01
Fine ceramics (advanced ceramics,
advanced technical ceramics) — Test
method for antibacterial activity
of semiconducting photocatalytic
materials under indoor lighting
environment
Céramiques techniques — Méthode d’essai de l’activité
antibactérienne des matériaux photocatalytiques semiconducteurs
dans un environnement d’éclairage intérieur
Reference number
©
ISO 2014
© ISO 2014
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ii © ISO 2014 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 2
5 Principle . 3
6 Materials . 3
6.1 Bacteria strains and preparation for tests . 3
6.2 Chemicals and implements . 3
7 Apparatus . 4
7.1 General . 4
7.2 Cover film . 5
7.3 Moisture preservation glass plate . 5
7.4 Glass tube or glass rod . 5
7.5 Light source . 5
7.6 UV sharp cut-off filter . 5
7.7 Illuminance meter . 6
8 Test piece . 6
9 Procedure. 6
9.1 General . 6
9.2 Cover film method . 7
9.3 Indoor lighting condition . 8
9.4 Measurement of number of living bacteria . 8
10 Calculation . 9
10.1 General . 9
10.2 Test requirement fulfilment validation . 9
10.3 Indoor light-active photocatalyst antibacterial activity value calculation .10
11 Test report .11
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.
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described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
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to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 206, Fine ceramics.
iv © ISO 2014 – All rights reserved

Introduction
A test method for cloths or textiles is not included in this International Standard because of a lack of
indoor-light-active photocatalytic cloths or textiles. When indoor-light-active photocatalytic cloths
or textiles have been developed, a suitable test method will be proposed with the remediated glass
adhesion method given in ISO 27447.
INTERNATIONAL STANDARD ISO 17094:2014(E)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Test method for antibacterial activity of
semiconducting photocatalytic materials under indoor
lighting environment
WARNING — Handling and manipulation of microorganisms that are potentially hazardous
requires a high degree of technical competence. Only personnel trained in microbiological
techniques should carry out tests.
1 Scope
This International Standard presents a test method for determining the antibacterial activity of materials
that contain an indoor-light-active photocatalytic material or have indoor-light-active photocatalytic
films on the surface by measuring the survival of bacteria after illumination with indoor light.
It is intended for use with different kinds of indoor-light-active photocatalytic materials used in
construction materials in flat sheet, board or plate shape that are the basic forms of materials for
various applications. It does not include powder, granular, or porous indoor-light-active photocatalytic
materials, nor is it applicable to cloths or textiles.
It is applicable to indoor-light-active photocatalytic materials produced for antibacterial application.
Other types of performance of indoor-light-active photocatalytic materials, i.e. decomposition of water
contaminants, self-cleaning, antifogging, and air purification, cannot be determined by this method.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 27447, Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for antibacterial
activity of semiconducting photocatalytic materials
ISO 14605, Fine ceramics (advanced ceramics, advanced technical ceramics) — Light source for testing
semiconducting photocatalytic materials used under indoor lighting environment
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
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, antifungal, self-cleaning, and antifogging actions
3.2
indoor-light-active photocatalyst
photocatalyst that functions under illumination with artificial light used for general lighting purposes
3.3
indoor lighting environment
illumination with artificial light source(s) used for general lighting purposes and excluding sunlight
3.4
indoor-light-active photocatalytic material
material in which or on which the indoor-light-active photocatalyst is added by coating, impregnation,
mixing, etc
3.5
antibacterial
condition inhibiting the growth of bacteria on the surface of flat surface materials
3.6
indoor-light-active photocatalyst antibacterial activity value
numerical difference between the logarithmic values of the total number of viable bacteria on the indoor-
light-active photocatalytic treated material and non-treated material after indoor light illumination
Note 1 to entry: This value includes the decrease of number of bacteria without indoor light illumination.
3.7
indoor-light-active photocatalyst antibacterial activity value with indoor light illumination
numerical difference between the logarithmic values of the total number of viable bacteria on the indoor-
light-active photocatalytic treated material after indoor light illumination and the same material kept
in the dark
4 Symbols
A average number of viable bacteria on non-treated test pieces, just after inoculation
B average number of viable bacteria on non-treated test pieces, after being kept in a dark
D
place
B average number of viable bacteria on non-treated test pieces, after indoor light illumina-
L
tion of intensity L
C average number of viable bacteria on indoor-light-active photocatalytic treated test
D
pieces, after being kept in dark place
C average number of viable bacteria on indoor-light-active photocatalytic treated test
L
pieces, after indoor light illumination of intensity L
D dilution factor
F
L illuminance of indoor light
L maximum logarithmic value of viable bacteria
max
L average logarithmic value of viable bacteria for three test pieces
mean
L minimum logarithmic value of viable bacteria
min
N number of viable bacteria
P bacteria concentration
R indoor-light-active photocatalyst antibacterial activity value, after illumination at a con-
L
stant intensity (L) on an indoor-light-active photocatalytic material
ΔR indoor-light-active photocatalyst antibacterial activity value with indoor light illumina-
tion
2 © ISO 2014 – All rights reserved

V volume of soybean-casein digest broth with lecithin and polysorbate 80 medium for
washout
Z average number of colonies in two Petri dishes
5 Principle
The method is used to obtain the antibacterial activity of indoor-light-active photocatalytic materials by
contact of a test piece with bacteria, under indoor lighting condition. The film cover method is available
for flat sheet, board, or plate-shaped materials.
The test piece is laid in a Petri dish and the bacterial suspension is dripped onto the test piece. Then
the cover film is placed on the suspension and the moisture conservation glass is placed on top of the
Petri dish. The Petri dish containing the test piece is exposed to light. After exposure, the test bacteria
are washed out of the test piece and the cover film. This washout suspension is measured by the viable
bacterial count method.
6 Materials
6.1 Bacteria strains and preparation for tests
6.1.1 Bacteria strains
The bacteria strains to be used in the test shall be the same as or equivalent to those described in Table 1
and supplied by an entity that is registered under the World Federation for Culture Collections or the
Japan Society for Culture Collections.
Table 1 — Bacteria strains to be used in test
Bacteria species WDCM code
Staphylococcus aureus WDCM 00195
Escherichia coli WDCM 00196
NOTE Refer to WDCM (World Data Centre for Microorganisms) and its website: http://
www.wdcm.org/.
NOTE If necessary, additional tests with other bacteria can be allowed.
6.1.2 Bacteria preparation
Aseptic manipulations using microorganisms should be performed in an adequate safety cabinet.
Inoculate each strain into slant culture medium (nutrient agar medium), incubate for 16 h to 24 h at
37 °C ± 1 °C, and then store in a refrigerator at 5 °C to 10 °C. Repeat subcultures within one month by
replicating this process. The maximum number of subcultures from the original strain transferred by
culture collection is 10. A slant culture shall not be stored for more than one month.
NOTE 1 In the case of bacteria stored in deep freezer, the maximum number of subcultures from original strain
transferred by culture collection is 10.
NOTE 2 If activity of used bacteria is maintained, agar plates can be used.
6.2 Chemicals and implements
6.2.1 General
Commercial media of same components described below can be used.
Volume of prepared media should be adjusted in accordance with the number of test pieces.
6.2.2 1/500 nutrient broth (1/500 NB)
For 100 ml of purified water, take 0,3 g meat extract, 1,0 g peptone, and 0,5 g sodium chloride, put them
into a flask and dissolve them thoroughly. When the contents are thoroughly dissolved, use a solutio
...