ISO/FDIS 21701
(Main)Textiles —Test method for accelerated hydrolysis of textile materials and biodegradation under controlled composting conditions of the resulting hydrolysate
Textiles —Test method for accelerated hydrolysis of textile materials and biodegradation under controlled composting conditions of the resulting hydrolysate
This document specifies a test method for the determination of the biodegradability of the hydrolysate of textile materials obtained after accelerated hydrolysis under controlled composting conditions by measurement of the amount of evolved carbon dioxide with a gas chromatography. This test method can be applied to petroleum-based man-made biodegradable textile materials which are manufactured from polyethylene terephthalate succinate, polycaprolactone, polypropylene carbonate, polybuthylene succinate or copolymer using them.
Textiles — Méthode d’essai pour hydrolyse accélérée des matières textiles et la biodégradation dans des conditions de compostage contrôlées de l'hydrolysat résultant
General Information
Relations
Standards Content (Sample)
FINAL DRAFT
International
Standard
ISO/TC 38
Textiles — Test method for
Secretariat: JISC
accelerated hydrolysis of textile
Voting begins on:
materials and biodegradation under
2025-08-05
controlled composting conditions of
Voting terminates on:
the resulting hydrolysate
2025-09-30
Textiles — Méthode d’essai pour hydrolyse accélérée des matières
textiles et la biodégradation dans des conditions de compostage
contrôlées de l'hydrolysat résultant
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 SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
FINAL DRAFT
International
Standard
ISO/TC 38
Textiles — Test method for
Secretariat: JISC
accelerated hydrolysis of textile
Voting begins on:
materials and biodegradation under
controlled composting conditions of
Voting terminates on:
the resulting hydrolysate
Textiles — Méthode d’essai pour hydrolyse accélérée des matières
textiles et la biodégradation dans des conditions de compostage
contrôlées de l'hydrolysat résultant
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 SUPPOR TING DOCUMENTATION.
© ISO 2025
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland Reference number
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Reference material . 3
6 Apparatus . 3
7 Test procedure . 4
7.1 Preparation of test material .4
7.2 Preparation of the inoculum .4
7.3 Accelerated hydrolysis test (abiotic test) . .4
7.4 Biodegradation test (biotic test) of hydrolysate .4
7.5 Gas chromatographic analysis .5
7.6 Non–dispersive infrared (NDIR) analysis .5
8 Calculation and expression of results . 5
8.1 Amount of carbon dioxide in grams by gas chromatography .5
8.2 Amount of carbon dioxide in grams by non-dispersive infrared .7
8.3 Percentage of biodegradation .7
8.4 Validity of results .8
9 Test report . 8
Annex A (informative) Example of apparatus . 9
Annex B (informative) Example of accelerated hydrolysis test results .11
Bibliography .12
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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 38, Textiles.
This second edition cancels and replaces the first edition (ISO 21701:2019), which has been technically
revised.
The main changes are as follows:
— in Clause 1, non-dispersive infrared has been added;
— in Clause 2, ISO 3071 has been added;
— in Clause 4, non-dispersive infrared has been added;
— in Clause 6, 6.7 Non-dispersive infrared(NDIR) has been added;
— in Clause 6, 6.9 pH-meter has been specified by ISO 3071;
— in Clause 7, 7.6 Non-dispersive infrared(NDIR) has been added;
— in Clause 8, 8.1 Amount of carbon dioxide in grams by gas chromatography has been modified;
— in Clause 8, 8.2 Amount of carbon dioxide in grams by non-dispersive infrared has been added;
— in Clause 9, d) the average flow rate and interval of sampling by non-dispersive infrared, f) date of test,
and g) any unusual features observed have been added;
— in Annex A, A.3, Non-dispersive infrared for thermal desorption has been added;
— in Annex A, A.4, Example of the analysis condition of gas cell has been added.
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
Textile fibres can be classified into natural fibres and man-made fibres according to ISO/TR 11827. Some
man-made fibres manufactured from organic materials are biodegradable and can be divided into three
major categories in relation to their origin, i.e. natural material base, biology base and petroleum base.
The representative bio-based, man-made biodegradable fibre is polylactide and petroleum-based, man-
made biodegradable fibres are manufactured from polyethylene terephthalate succinate, polycaprolactone,
polypropylene carbonate, polybuthylene succinate or copolymer using them.
The biodegradation of petroleum-based fibres is relatively slow compared to biology-based or natural fibres
due to the chemical structure. In addition, the rate of biodegradation of textile materials such as fibres and
yarns can also be affected negatively by high molecular weight, degree of crystallinity and orientation
occurred during the spinning. Although some standards refer to the instrument analysis, such as gas
chromatograph or infrared analysis, the process and calculation method are not standardized. Therefore,
it is difficult to determine the biodegradation of petroleum-based textile materials using the existing
standards available for natural fibres, biology-based fibres or plastic materials used for packaging.
To overcome these difficulties, the new test method is proposed by a combination of accelerated hydrolysis
and biodegradation using instrument analysis for analysis of evolved carbon dioxide.
Under the composting of textile materials both mechanisms, abiotic and biotic processes, operate together
and the microorganisms eventually remove the hydrolysate in a synergistic process. It is difficult and
time consuming to reproduce this in the laboratory. For convenience, the accelerated hydrolysis, which is
an abiotic process, should be carried out followed by biodegradation subsequently. The rate and extent of
molecular weight loss is measured as indicative of losses in physical properties from accelerated hydrolysis
and then the biodegradability of hydrolysate is estimated by direct measurement of evolved carbon dioxide
with a gas chromatograph.
v
FINAL DRAFT International Standard ISO/FDIS 21701:2025(en)
Textiles — Test method for accelerated hydrolysis of textile
materials and biodegradation under controlled composting
conditions of the resulting hydrolysate
1 Scope
This document specifies a test method for the determination of the biodegradability of the hydrolysate
of textile materials obtained after accelerated hydrolysis under controlled composting conditions, by
measurement of the amount of evolved carbon dioxide with a gas chromatography or non-dispersive
infrared.
This test method can be applied to petroleum-based, man-made biodegradable textile materials which
are manufactured from polyethylene terephthalate succinate, polycaprolactone, polypropylene carbonate,
polybuthylene succinate or copolymer using them.
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 1628-1, Plastics — Determination of the viscosity of polymers in dilute solution using capillary viscometers
— Part 1: Ge
...
ISO/TC 38
Secretariat: JISC
Date: 2025-06-23
Textiles — Test method for accelerated hydrolysis of textile
materials and biodegradation under controlled composting
conditions of the resulting hydrolysate
Textiles — Méthode d’essai pour hydrolyse accélérée des matières textiles et la biodégradation dans des
conditions de compostage contrôlées de l'hydrolysat résultant
FDIS stage
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'sISO’s member body in the country of the requester.
ISO Copyright Officecopyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
Email: copyright@iso.org
E-mail: copyright@iso.org
Website: www.iso.orgwww.iso.org
Published in Switzerland.
ii
Contents Page
Foreword . v
Introduction . vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Reference material . 3
6 Apparatus . 3
7 Test procedure . 4
8 Calculation and expression of results . 5
9 Test report . 10
Annex A (informative) Example of apparatus . 11
Annex B (informative) Example of accelerated hydrolysis test results . 13
Bibliography . 14
Contents
Foreword . iv
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Reference material . 3
6 Apparatus . 3
7 Test procedure . 4
7.1 Preparation of test material . 4
7.2 Preparation of the inoculum . 4
7.3 Accelerated hydrolysis test (abiotic test) . 4
7.4 Biodegradation test (biotic test) of hydrolysate . 5
7.5 Gas chromatographic analysis . 5
7.6 Non – dispersive infrared (NDIR) analysis . 5
8 Calculation and expression of results . 5
8.1 Amount of carbon dioxide in grams by gas chromatography . 5
Figure 1 — Calculation of the accumulative concentration . 7
8.2 Amount of carbon dioxide in grams by non-dispersive infrared . 8
8.3 Percentage of biodegradation . 8
8.4 Validity of results . 8
9 Test report . 8
Annex A (informative) Example of apparatus . 10
iii
Annex B (informative) Example of accelerated hydrolysis test results . 12
B.1 Test condition for accelerated hydrolysis test . 12
B.2 Test results . 12
Table B.1 Weight-average molecular weight after accelerated hydrolysis test . 12
Table B.2 Initial viscosity after accelerated hydrolysis test . 12
Bibliography . 13
iv
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents.www.iso.org/patents. ISO shall not be held responsible for identifying any or all such
patent rights.
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.htmlwww.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 38, Textiles.
This second edition cancels and replaces the first edition (ISO 21701:2019), which has been technically
revised.
The main changes are as follows:
— — in Clause 1,1, non-dispersive infrared has been added;
— — in Clause 2,2, ISO 3071 has been added;
— — in Clause 4,4, non-dispersive infrared has been added;
— — in Clause 6, 6.76, 6.7 Non-dispersive infrared(NDIR) has been added;
— — in Clause 6, 6.96, 6.9 pH-meter has been specified by ISO 3071;
— — in Clause 7, 7.67, 7.6 Non-dispersive infrared(NDIR) has been added;
— — in Clause 8, 8.18, 8.1 Amount of carbon dioxide in grams by gas chromatography has been modified;
— — in Clause 8, 8.28, 8.2 Amount of carbon dioxide in grams by non-dispersive infrared has been added;
— — in Clause 9,in 9, d) the average flow rate and interval of sampling by non-dispersive infrared, f) date of
test, and g) any unusual features observed have been added;
v
— — in Annex A, A3.Annex A, A.3, Non-dispersive infrared for thermal desorption has been added;
— — in Annex A, A4.in Annex A, A.4, Example of the analysis condition of gas cell has been added.
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.htmlwww.iso.org/members.html.
vi
Introduction
Textile fibres can be classified into natural fibres and man-made fibres according to ISO/TR 11827. Some man-
made fibres manufactured from organic materials are biodegradable and can be divided into three major
categories in relation to their origin, i.e. natural material base, biology base and petroleum base. The
representative bio-based, man-made biodegradable fibre is polylactide and petroleum-based, man-made
biodegradable fibres are manufactured from polyethylene terephthalate succinate, polycaprolactone,
polypropylene carbonate, polybuthylene succinate or copolymer using them.
The biodegradation of petroleum-based fibres is relatively slow compared to biology-based or natural fibres
due to the chemical structure. In addition, the rate of biodegradation of textile materials such as fibres and
yarns can also be affected negatively by high molecular weight, degree of crystallinity and orientation occurred
during the spinning. Although some standards refer to the instrument analysis, such as gas chromatograph or
infrared analysis, the process and calculation method are not standardized. Therefore, it is difficult to
determine the biodegradation of petroleum-based textile materials using the existing standards available for
natural fibres, biology-based fibres or plastic materials used for packaging.
To overcome these difficulties, the new test method is proposed by a combination of accelerated hydrolysis
and biodegradation using instrument analysis for analysis of evolved carbon dioxide.
Under the composting of textile materials both mechanisms, abiotic and biotic processes, operate together
and the microorganisms eventually remove the hydrolysate in a synergistic process. It is difficult and time
consuming to reproduce this in the laboratory. For convenience, the accelerated hydrolysis, which is an abiotic
process, should be carried out followed by biodegradation subsequently. The rate and extent of molecular
weight loss is measured as indicative of losses in physical properties from accelerated hydrolysis and then the
biodegradability of hydrolysate is estimated by direct measurement of evolved carbon dioxide with a gas
chromatograph.
vii
Final Draft International Standard ISO/FDIS 21701:2025(en)
Textiles — Test method for accelerated hydrolysis of textile materials
and biodegradation under controlled composting conditions of the
resulting hydrolysate
1 Scope
This document specifies a test method for the determination of the biodegradability of the hydrolysate of
textile materials obtained after accelerated hydrolysis under controlled composting conditions, by
measurement of the amount of evolved carbon dioxide with a gas chromatography or non-dispersive infrared.
This test
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.