ISO/TS 23650:2021

Nanotechnologies — Evaluation of the antimicrobial performance of textiles containing manufactured nanomaterials

This document specifies the antimicrobial performance assessment method of textiles containing manufactured (metals/metal oxides) nanomaterials (TCMNMs). The textiles in this document include fabric, yarn and fibre in which manufactured nanomaterials are used during production or finishing process. Further, this document also specifies protocols to determine the quantity of nanomaterials released from textile following washing and/or exposure to artificial human body sweat. This document only covers the antibacterial, antifungal, and the anti-odour performance assessment method of TCMNMs. This document does not cover textiles that have therapeutic application as well as environment, health and safety (EHS) issues related to TCMNMs. Further, it does not cover the release of nanomaterials from TCMNMs as a result of aging, dry attrition and abrasion, although it is considered as an effective factor in releasing nanomaterials.

Nanotechnologies — Evaluation de la performance antimicrobienne des textiles contenant des nanomatériaux manufacturés

General Information

• Status: Published
• Publication Date: 06-Oct-2021
• ICS: 07.120 - Nanotechnologies
• Technical Committee: ISO/TC 229 - Nanotechnologies
• Drafting Committee: ISO/TC 229/WG 5 - Products and Applications
• Current Stage: 9020 - International Standard under periodical review
• Start Date: 15-Oct-2024
• Completion Date: 15-Oct-2024

Standards Content (Sample)

TECHNICAL ISO/TS
SPECIFICATION 23650
First edition
2021-10
Nanotechnologies — Evaluation of
the antimicrobial performance of
textiles containing manufactured
nanomaterials
Nanotechnologies — Evaluation de la performance antimicrobienne
des textiles contenant des nanomatériaux manufacturés
Reference number
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms.2
5 Characteristics of metal or metal oxide nanomaterials in TCMNMs.3
5.1 General . 3
5.2 Physicochemical characteristics of metal or metal oxide nanomaterials . 3
5.3 Characterization methods. 4
6 Measurement of the released metal or metal oxide nanomaterials .4
6.1 Principle . 4
6.2 Human perspiration solution preparation . 4
6.2.1 General . 4
6.2.2 Measurement method . 4
6.3 Washing procedure . 5
7 Determination of antimicrobial activities of TCMNMs . 5
7.1 Principle . 5
7.2 Antibacterial activity . 5
7.3 Antifungal activity . 5
7.4 Anti-odour property . 6
8 Test report . 6
Annex A (informative) Physical characterization techniques of nanomaterials in TCMNMs .9
Annex B (informative) Chemical characterization of nanomaterials in TCMNMs .10
Annex C (informative) Determination of antibacterial, antifungal, and anti-odour activity
of TCMNMs .11
Bibliography .13
iii
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 229, Nanotechnologies.
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
Introduction
The utilization of nanotechnology in textile industry has presented novel functions such as
antimicrobial activity, stain resistance, flame retardancy, mechanical strength enhancement, UV
resistance, and wrinkle resistance into the conventional textiles without significant loss or change of
[17]
the original properties. According to the nanodatabase website there are already over 400 textiles
containing manufactured nanomaterials (TCMNMs), making them the second largest market among
other nanoproducts.
The rapid and continued growth of TCMNMs is increasing the need to develop international standards
specific for manufactured nanomaterials (MNMs) in textiles and testing processes guidelines. It is a
dual need of industry and consumer.
TCMNMs can be classified into three groups based on how nanomaterials are integrated into the
[1]
textiles including nanofinished, nanocomposite, and nanofibrous textiles :
a) Nanofinished textiles: The textiles that the applied nanoscale property is added after the textile
fabrication through post-manufacture treatments and coatings to create nanostructured surfaces
on fibre media. Most nanotextiles on the consumer market belong to this category.
b) Nanocomposite textiles: The textiles composed of fibres containing one or more nanostructured
or nanoscale components produced by pre-manufacture integration of nanoscale properties into
fibrous components.
c) Nanofibrous textiles: The textiles made of nanofibres which have a nanoscale cross-sectional area
and may or may not have a nanoscale length.
Natural and manufactured textile fibres can be treated with different nanomaterials and chemicals to
provide enhanced antimicrobial properties. The antimicrobial activities of TCMNMs include activities
against bacteria, fungal, viruses, and other microorganisms. Also, the antimicrobial activities can help
to impart anti-odour property as the consequence of the reduced microbial activity. For antimicrobial
TCMNMs, various metals, mainly silver and copper, and metal oxides such as copper oxide (CuO),
titanium dioxide (TiO ) and zinc oxide (ZnO) are normally used.
Several characteristics of MNMs have great impacts on their antimicrobial performance including
size, shape, surface area, chemical composition, surface chemistry and surface charge. The size and
shape of MNMs have important impacts on their antimicrobial property due to their association to
their surface area. Generally, the antibacterial properties of nanoparticles are size-dependent. Smaller
particles with higher surface area to volume ratio have more contact with either bacteria or fungi cells,
[2]
or both, leading to improve either the bactericidal or fungicidal effectiveness, or both . Therefore,
when they incorporate in textiles even at low concentrations they show noticeable antimicrobial
[3]-[5]
activity compared to their micro-and macro scale counterparts. The shape of MNMs remarkably
influences the rate of interaction and uptake by microbial cells. For instance, spherical-shaped of
[7]
gold nanoparticles demonstrated higher cellular uptake than nanorod shaped particles . Surface
charge of MNMs is another important characteristic that can be measured by Zeta potential method.
The antimicrobial effect of MNMs is triggered by the electrostatic interaction between the positively
charged MNMs and the negatively charged microbial cell membranes ultimately leading to cell damage
and inhibition of their growth and reproduction. Surface chemistry of MNMs has an important effect
on their antimicrobial activity. The presence of functional groups, capping agents or biomolecules
on the surface of nanomaterials has also potential influence in their antibacterial activities. Surface
functionalization of antimicrobial nanoparticles such as silver nanoparticles with bioactive molecules
[8]
exhibited enhanced antibacterial activity compared to the bare ones . The above-mentioned inter-
relationship highlights the important effect of physiochemical characteristics on antimicrobial
performance of TCMNMs.
Currently, there are various antimicrobial TCMNMs products in the market such as underwear,
shirts, socks, and bed sheets/covers. The antimicrobial mechanism of action of nanomaterials can
generally be described as one of three models: oxidative stress induction, metal ion release, or non-
[1]
oxidative mechanisms, which can occur simultaneously as well . The antimicrobial activity of
v
TCMNMs can decline significantly after several washing cycles and exposure to body sweat due to the
possible release of incorporated nanomaterials and also the chemical action of sweat and laundering
solution on the nanocompounds. Currently, there is no ISO document specific to TCMNM products.
Therefore, the development of a standard to determine antimicrobial performance of TCMNMs
subjected to washing process and body sweating can facilitate the trade and growth of market. It is
worth mentioning that already published ISO standards are related to the assessment of antimicrobial
properties of conventional textiles. Moreover, there is an ASTM standard document for detection and
[9]
characterization of silver nanomaterials in textiles . However, these documents do not address the
potential release of nanomaterials/nanostructure from TCMNNs following washing or sweating and
their possible consequence on the antimicrobial activity of these textiles.
This document does not address nano-safety and environmental impact of the release of nanomaterials
from TCMNMs into the air, water and to landfill. Data related to the release of nanomaterials from the
fabrics under different conditions such as sweating, mechanical stresses (repetitive abrasion) during
washing process in a laundry machine, are considered as essential information for understanding the
potential releases to the environment.
Artificial sweat solution is an appropriate candidate to use as a material to resemble the human skin
sweat to determine the amount of release of nanomaterials from TCMNMs to human body. For many
TCMNMs applications, such as human clothes, there is a high possibility of skin contact and interaction
[10]
with incorporated nanomaterials . In such condition, the involved interaction and r
...

TECHNICAL ISO/TS
SPECIFICATION 23650
First edition
2021-10
Nanotechnologies — Evaluation of
the antimicrobial performance of
textiles containing manufactured
nanomaterials
Nanotechnologies — Evaluation de la performance antimicrobienne
des textiles contenant des nanomatériaux manufacturés
Reference number
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms.2
5 Characteristics of metal or metal oxide nanomaterials in TCMNMs.3
5.1 General . 3
5.2 Physicochemical characteristics of metal or metal oxide nanomaterials . 3
5.3 Characterization methods. 4
6 Measurement of the released metal or metal oxide nanomaterials .4
6.1 Principle . 4
6.2 Human perspiration solution preparation . 4
6.2.1 General . 4
6.2.2 Measurement method . 4
6.3 Washing procedure . 5
7 Determination of antimicrobial activities of TCMNMs . 5
7.1 Principle . 5
7.2 Antibacterial activity . 5
7.3 Antifungal activity . 5
7.4 Anti-odour property . 6
8 Test report . 6
Annex A (informative) Physical characterization techniques of nanomaterials in TCMNMs .9
Annex B (informative) Chemical characterization of nanomaterials in TCMNMs .10
Annex C (informative) Determination of antibacterial, antifungal, and anti-odour activity
of TCMNMs .11
Bibliography .13
iii
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 229, Nanotechnologies.
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
Introduction
The utilization of nanotechnology in textile industry has presented novel functions such as
antimicrobial activity, stain resistance, flame retardancy, mechanical strength enhancement, UV
resistance, and wrinkle resistance into the conventional textiles without significant loss or change of
[17]
the original properties. According to the nanodatabase website there are already over 400 textiles
containing manufactured nanomaterials (TCMNMs), making them the second largest market among
other nanoproducts.
The rapid and continued growth of TCMNMs is increasing the need to develop international standards
specific for manufactured nanomaterials (MNMs) in textiles and testing processes guidelines. It is a
dual need of industry and consumer.
TCMNMs can be classified into three groups based on how nanomaterials are integrated into the
[1]
textiles including nanofinished, nanocomposite, and nanofibrous textiles :
a) Nanofinished textiles: The textiles that the applied nanoscale property is added after the textile
fabrication through post-manufacture treatments and coatings to create nanostructured surfaces
on fibre media. Most nanotextiles on the consumer market belong to this category.
b) Nanocomposite textiles: The textiles composed of fibres containing one or more nanostructured
or nanoscale components produced by pre-manufacture integration of nanoscale properties into
fibrous components.
c) Nanofibrous textiles: The textiles made of nanofibres which have a nanoscale cross-sectional area
and may or may not have a nanoscale length.
Natural and manufactured textile fibres can be treated with different nanomaterials and chemicals to
provide enhanced antimicrobial properties. The antimicrobial activities of TCMNMs include activities
against bacteria, fungal, viruses, and other microorganisms. Also, the antimicrobial activities can help
to impart anti-odour property as the consequence of the reduced microbial activity. For antimicrobial
TCMNMs, various metals, mainly silver and copper, and metal oxides such as copper oxide (CuO),
titanium dioxide (TiO ) and zinc oxide (ZnO) are normally used.
Several characteristics of MNMs have great impacts on their antimicrobial performance including
size, shape, surface area, chemical composition, surface chemistry and surface charge. The size and
shape of MNMs have important impacts on their antimicrobial property due to their association to
their surface area. Generally, the antibacterial properties of nanoparticles are size-dependent. Smaller
particles with higher surface area to volume ratio have more contact with either bacteria or fungi cells,
[2]
or both, leading to improve either the bactericidal or fungicidal effectiveness, or both . Therefore,
when they incorporate in textiles even at low concentrations they show noticeable antimicrobial
[3]-[5]
activity compared to their micro-and macro scale counterparts. The shape of MNMs remarkably
influences the rate of interaction and uptake by microbial cells. For instance, spherical-shaped of
[7]
gold nanoparticles demonstrated higher cellular uptake than nanorod shaped particles . Surface
charge of MNMs is another important characteristic that can be measured by Zeta potential method.
The antimicrobial effect of MNMs is triggered by the electrostatic interaction between the positively
charged MNMs and the negatively charged microbial cell membranes ultimately leading to cell damage
and inhibition of their growth and reproduction. Surface chemistry of MNMs has an important effect
on their antimicrobial activity. The presence of functional groups, capping agents or biomolecules
on the surface of nanomaterials has also potential influence in their antibacterial activities. Surface
functionalization of antimicrobial nanoparticles such as silver nanoparticles with bioactive molecules
[8]
exhibited enhanced antibacterial activity compared to the bare ones . The above-mentioned inter-
relationship highlights the important effect of physiochemical characteristics on antimicrobial
performance of TCMNMs.
Currently, there are various antimicrobial TCMNMs products in the market such as underwear,
shirts, socks, and bed sheets/covers. The antimicrobial mechanism of action of nanomaterials can
generally be described as one of three models: oxidative stress induction, metal ion release, or non-
[1]
oxidative mechanisms, which can occur simultaneously as well . The antimicrobial activity of
v
TCMNMs can decline significantly after several washing cycles and exposure to body sweat due to the
possible release of incorporated nanomaterials and also the chemical action of sweat and laundering
solution on the nanocompounds. Currently, there is no ISO document specific to TCMNM products.
Therefore, the development of a standard to determine antimicrobial performance of TCMNMs
subjected to washing process and body sweating can facilitate the trade and growth of market. It is
worth mentioning that already published ISO standards are related to the assessment of antimicrobial
properties of conventional textiles. Moreover, there is an ASTM standard document for detection and
[9]
characterization of silver nanomaterials in textiles . However, these documents do not address the
potential release of nanomaterials/nanostructure from TCMNNs following washing or sweating and
their possible consequence on the antimicrobial activity of these textiles.
This document does not address nano-safety and environmental impact of the release of nanomaterials
from TCMNMs into the air, water and to landfill. Data related to the release of nanomaterials from the
fabrics under different conditions such as sweating, mechanical stresses (repetitive abrasion) during
washing process in a laundry machine, are considered as essential information for understanding the
potential releases to the environment.
Artificial sweat solution is an appropriate candidate to use as a material to resemble the human skin
sweat to determine the amount of release of nanomaterials from TCMNMs to human body. For many
TCMNMs applications, such as human clothes, there is a high possibility of skin contact and interaction
[10]
with incorporated nanomaterials . In such condition, the involved interaction and r
...