ISO/FDIS 8810

Plastics — Determination of residual peroxide — Gas chromatography method

This document specifies a method for determination of di-tert-butyl peroxide (DTBP) and 2, 5-Dimethyl-2, 5-di (tert-butylperoxy) hexane (DBPH) in plastic by using gas chromatography. This document is applicable to the determination of the content of residual peroxides in plastics and their products, which using the peroxides as a degradation agent or crosslinking agent during plastic processing, or as an additive during polymerization, thereby remaining in degraded polypropylene, crosslinked polyethylene, polystyrene and other plastics.

Plastiques — Détermination du peroxyde résiduel — Méthode par chromatographie en phase gazeuse

General Information

• Status: Not Published
• ICS: 83.080.01 - Plastics in general
• Technical Committee: ISO/TC 61/SC 5 - Physical-chemical properties
• Drafting Committee: ISO/TC 61/SC 5 - Physical-chemical properties
• Current Stage: 5020 - FDIS ballot initiated: 2 months. Proof sent to secretariat
• Start Date: 03-Mar-2026
• Completion Date: 03-Mar-2026

Overview

ISO/FDIS 8810: Plastics - Determination of Residual Peroxide - Gas Chromatography Method is an international standard developed by ISO's Technical Committee 61, Subcommittee 5 (ISO/TC 61/SC 5). This document outlines a precise method for determining residual peroxide compounds-specifically di-tert-butyl peroxide (DTBP) and 2,5-Dimethyl-2,5-di(tert-butylperoxy) hexane (DBPH)-in plastics using gas chromatography (GC). The standard is applicable to a range of plastics and plastic products that utilize peroxides as degradation agents, crosslinking agents, or additives during polymerization and processing, including degraded polypropylene, crosslinked polyethylene, polystyrene, and similar materials.

The accurate determination of residual peroxides is essential for assessing material safety, compliance, and quality control within the plastics industry. ISO/FDIS 8810 provides a robust, reproducible analytical approach by gas chromatography, facilitating industry-wide consistency and harmonization.

Key Topics

• Scope and Applicability: ISO/FDIS 8810 specifies the method to identify and quantify residual DTBP and DBPH in plastics by GC. Applicability extends to various polymers where peroxides are used during manufacturing or processing.
• Safety and Laboratory Practice: Users must follow standard laboratory safety procedures and employ appropriate protections when handling toxic reagents such as tetrahydrofuran, toluene, and other solvents.
• Sample Preparation: The method details preparation of both resin granules and product samples, including cutting, extraction with solvents, and filtration.
• Calibration and Internal Standards: The process includes preparing a series of calibration solutions using recognized internal reference substances (e.g., undecane), ensuring accuracy and repeatability.
• Gas Chromatography Analysis: The method supports both flame ionization detection (GC-FID) and mass spectrometry (GC-MS), according to the detection needs and sample characteristics.
• Result Calculation and Reporting: Detailed formulas guide users in converting measured data into precise residual peroxide content, with requirements for complete and standardized reporting of results.
• Precision and Validation: Interlaboratory precision and method validation are highlighted to support reliability and regulatory acceptance.

Applications

The ISO/FDIS 8810 standard holds significant practical value for:

• Manufacturers of Polyolefin and Polystyrene Products: For controlling and verifying the removal of residual peroxides in polypropylene, polyethylene, and related materials after processing.
• Quality Control Laboratories: Supporting routine analysis of residual peroxides to meet regulatory requirements and ensure material safety for consumer, industrial, and technical applications.
• R&D in Polymer Chemistry: Facilitating method validation when developing new formulations or optimizing crosslinking and degradation strategies involving peroxides.
• Regulatory Compliance: Providing a harmonized methodology for global compliance documentation and quality assurance within the supply chain for plastic materials.
• Health and Environmental Safety: Identifying and mitigating risks related to residual peroxide compounds which may impact product safety and environmental compliance.

Related Standards

Organizations seeking comprehensive coverage or wishing to expand their testing protocols may reference the following related standards:

• ISO 5725-2:Accuracy (trueness and precision) of measurement methods and results-Provides guidelines on the determination of repeatability and reproducibility, supporting the validation of results from ISO/FDIS 8810.
• ISO 648:Laboratory glassware - Single-volume pipettes-Ensures precision in volumetric measurements during sample preparation.
• ISO 1042:Laboratory glassware - One-mark volumetric flasks-Specifies requirements for volumetric accuracy in solution preparation.
• ASTM D7210-21:Standard Practice for Extraction of Additives in Polyolefin Plastics-US standard offering extraction procedures that complement peroxide determination in plastics.

Adhering to ISO/FDIS 8810 helps ensure product quality, regulatory compliance, and safety in plastic manufacturing processes involving peroxide agents. The standard’s use of gas chromatography provides a reliable, sensitive approach for precise quantification of residual peroxides.

Standards Content (Sample)

DRAFT
International
Standard
ISO/DIS 8810
ISO/TC 61/SC 5
Plastics — Determination
Secretariat: DIN
of residual peroxide — Gas
Voting begins on:
chromatography method
2025-06-06
Plastiques — Détermination du peroxyde résiduel — Méthode
Voting terminates on:
par chromatographie en phase gazeuse
2025-08-29
ICS: 83.080.01
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.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
This document is circulated as received from the committee secretariat.
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
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 SUPPORTING DOCUMENTATION.
Reference number
ISO/DIS 8810:2025(en)
DRAFT
ISO/DIS 8810:2025(en)
International
Standard
ISO/DIS 8810
ISO/TC 61/SC 5
Plastics — Determination
Secretariat: DIN
of residual peroxide — Gas
Voting begins on:
chromatography method
Plastiques — Détermination du peroxyde résiduel — Méthode
Voting terminates on:
par chromatographie en phase gazeuse
ICS: 83.080.01
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.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2025
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
STANDARDS MAY ON OCCASION HAVE TO
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
This document is circulated as received from the committee secretariat. BE CONSIDERED IN THE LIGHT OF THEIR
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
ISO copyright office
RECIPIENTS OF THIS DRAFT ARE INVITED
CP 401 • Ch. de Blandonnet 8
TO SUBMIT, WITH THEIR COMMENTS,
CH-1214 Vernier, Geneva
NOTIFICATION OF ANY RELEVANT PATENT
Phone: [phone]
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 8810:2025(en)
ii
ISO/DIS 8810:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagents . 2
6 Apparatus . 2
7 Preparation of sample . 3
8 Procedure . 3
8.1 Preparation of internal calibration solutions .3
8.2 Preparation of test solution .3
8.3 Preparation of the calibration curve .3
8.4 Determination .5
9 Calculation . 5
10 Precision . 6
11 Test report . 6
Annex A (informative) Examples of operating conditions . 7
Annex B (informative) Peroxides (DTBP and DBPH) chromatograms . 9
Annex C (informative) Precision and Accuracy of the method .12
Bibliography . 14

iii
ISO/DIS 8810:2025(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 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).
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 61, Plastics, Subcommittee SC 5, Physical-
Chemical Properties.
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/DIS 8810:2025(en)
Introduction
Peroxide has many applications in polymer preparation, such as: used as a degradation agent in the
degradation reaction of ultra-high fluidity polypropylene (PP) and a variety of polymers, as a crosslinking
agent in polyethylene’s (PE) crosslinking reaction, as initiator for free radical polymerization, as a
vulcanizing agent for rubber vulcanization, etc. For health reasons and stable product quality, the content of
residual peroxide in plastics, especially in peroxide-degraded polypropylene (PP) needs to be determined.
Chromatography is the main method for the determination of peroxide.

v
DRAFT International Standard ISO/DIS 8810:2025(en)
Plastics — Determination of residual peroxide — Gas
chromatography method
WARNING — Persons using this document should be familiar with normal laboratory practice. This
document does not purport to address all of the safety problems, if any, associated with its use. It
is the responsibility of the user to establish appropriate safety and health practices and to ensure
compliance with any national regulatory conditions.
IMPORTANT — It is absolutely essential that tests conducted in accordance with this document be
carried out by suitably trained staff.
1 Scope
This document specifies a method for the determination of di-tert-butyl peroxide (DTBP) and 2, 5-Dimethyl-2,
5-di (tert-butylperoxy) hexane (DBPH) in plastics by using gas chromatography.
This document is applicable to the determination of the content of residual peroxides in plastics and their
products, which use peroxides as a degradation agent or crosslinking agent during plastics processing, or as
an additive during polymerization, thereby remaining in degraded polypropylene, crosslinked polyethylene,
polystyrene and other plastics.
NOTE The applicability of this method to other peroxides is possible when the method is validated for each case.
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 648, Laboratory glassware — Single-volume pipettes
ISO 1042, Laboratory glassware — One-mark volumetric flasks
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Principle
The test sample is extracted by ultrasonic bath with tetrahydrofuran or other suitable solvent. After the
extract solution is cooled, the internal standard is added, and the solution is shaken and filtered. The residual
peroxides in the extract solution are determined by gas chromatography (GC) with suitable detection
technique.
ISO/DIS 8810:2025(en)
5 Reagents
During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and distilled
or demineralized water or water of equivalent purity.
5.1 Di-tert-butyl peroxide (DTBP), CAS No. 110-05-4, minimum of 95 % purity.
5.2 2, 5-Dimethyl-2, 5-di (tert-butylperoxy) hexane (DBPH), CAS No. 78-63-7, minimum of 93 % purity.
5.3 Solvent, any product which will completely dissolve the internal reference and the target peroxides
(DTBP and DBPH) to give a stable solution, and which meets the following requirements:
— is inert (does not react with the resin or the internal standard under the test conditions);
— is compatible with the constituents of the chromatographic column;
— has a retention time different from those of the peroxides and the internal reference.
Examples of solvents which meet the above-mentioned requirements are:
— tetrahydrofuran (THF), CAS No. 109-99-9 (recommended);
— toluene, CAS No. 108-88-3;
— trichloromethane, CAS No. 67-66-3.
WARNING — The reagents used in this method are toxic. Safety precautions are necessary.
5.4 Internal reference substance, Undecane, CAS No. 1120-21-4, analytical grade or higher.
The internal reference substance shall not be present in the test portion matrix. Other compounds may be
used as alternative internal reference substances.
5.5 Initial calibration solution, 100 mg/l of DTBP and DBPH, each in tetrahydrofuran or other suitable
solvent.
The ini
...

FINAL DRAFT
International
Standard
ISO/TC 61/SC 5
Plastics — Determination
Secretariat: DIN
of residual peroxide — Gas
Voting begins on:
chromatography method
2026-03-03
Plastiques — Détermination du peroxyde résiduel — Méthode
Voting terminates on:
par chromatographie en phase gazeuse
2026-04-28
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 61/SC 5
Plastics — Determination
Secretariat: DIN
of residual peroxide — Gas
Voting begins on:
chromatography method
Plastiques — Détermination du peroxyde résiduel — Méthode
Voting terminates on:
par chromatographie en phase gazeuse
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 2026
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: [phone]
Email: [e-mail]
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 . 1
5 Reagents . 2
6 Apparatus . 2
7 Preparation of sample . 3
8 Procedure . 3
8.1 Preparation of internal calibration solutions .3
8.2 Preparation of test solution .3
8.3 Preparation of the calibration curve .4
8.4 Determination .4
9 Calculation . 4
10 Precision . 5
11 Test report . 5
Annex A (informative) Examples of operating conditions . 6
Annex B (informative) Peroxides (DTBP and DBPH) chromatograms . 8
Annex C (informative) Precision and accuracy of the method .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).
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 61, Plastics, Subcommittee SC 5, Physical-
chemical properties.
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
Peroxide has many applications in polymer preparation, such as: used as a degradation agent in the
degradation reaction of ultra-high fluidity polypropylene (PP) and a variety of polymers, as a crosslinking
agent in polyethylene’s (PE) crosslinking reaction, as initiator for free radical polymerization, as a
vulcanizing agent for rubber vulcanization, etc. For health reasons and stable product quality, the content of
residual peroxide in plastics, especially in peroxide-degraded polypropylene (PP) needs to be determined.
Chromatography is the main method for the determination of peroxide.

v
FINAL DRAFT International Standard ISO/FDIS 8810:2026(en)
Plastics — Determination of residual peroxide — Gas
chromatography method
WARNING — Persons using this document should be familiar with normal laboratory practice. This
document does not purport to address all of the safety problems, if any, associated with its use. It is
the responsibility of the user to establish appropriate safety and health practices and to determine
any applicable national regulatory conditions prior to use.
IMPORTANT — It is absolutely essential that tests conducted in accordance with this document be
carried out by suitably trained staff.
1 Scope
This document specifies a method for the determination of di-tert-butyl peroxide (DTBP) and 2, 5-Dimethyl-2,
5-di (tert-butylperoxy) hexane (DBPH) in plastics by using gas chromatography.
This document is applicable to the determination of the content of residual peroxides in plastics and their
products, which use peroxides as a degradation agent or crosslinking agent during plastics processing, or as
an additive during polymerization, thereby remaining in degraded polypropylene, crosslinked polyethylene,
polystyrene and other plastics.
NOTE The applicability of this method to other peroxides is possible when the method is validated for each case.
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 648, Laboratory glassware — Single-volume pipettes
ISO 1042, Laboratory glassware — One-mark volumetric flasks
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
4 Principle
The test sample is extracted by ultrasonic bath with tetrahydrofuran or other suitable solvent. After the
extract solution is cooled, the internal standard is added, and the solution is shaken and filtered. The residual
peroxides in the extract solution are determined by gas chromatography (GC) with suitable detection
technique.
5 Reagents
During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and distilled
or demineralized water or water of equivalent purity.
®1)
5.1 Di-tert-butyl peroxide (DTBP), CAS RN . 110-05-4, minimum of 95 % purity.
®1)
5.2 2, 5-Dimethyl-2, 5-di (tert-butylperoxy) hexane (DBPH), CAS RN 78-63-7, minimum of 93 %
purity.
5.3 Solvent, any product which will completely dissolve the internal reference and the target peroxides
(DTBP and DBPH) to give a stable solution, and which meets the following requirements:
— is inert (does not react with the resin or the internal standard under the test conditions);
— is compatible with the constituents of the chromatographic column;
— has a retention time different from those of the peroxides and the internal reference.
Examples of solvents which meet the above-mentioned requirements are:
®1)
— tetrahydrofuran (THF), CAS RN 109-99-9 (recommended);
®1)
— toluene, CAS RN 108-88-3;
®1)
— trichloromethane, CAS RN 67-66-3.
WARNING — The reagents used in this method are toxic. Safety precautions are necessary.
®1)
5.4 Internal reference substance, Undecane, CAS RN 1120-21-4, analytical grade or higher.
The internal reference substance shall not be present in the test portion matrix. Other compounds may be
used as alternative internal reference substances.
5.5 Initial calibration solution, 100 mg/l of DTBP and DBPH, each in tetrahydrofuran or other suitable
solvent.
The initial calibration solution should be properly stored at 4 °C to prevent change of concentration. It is
recommended that the solution should be prepared at least every three months.
5.6 Internal reference solution, 100 mg/l of undecane or others, in tetrahydrofuran or other suitable
solvent.
The internal stock solution should be properly stored at 4 °C to prevent change of concentration. It is
recommended that the solution should be prepared at
...

ISO/TC 61/SC 5/WG 11
Secretariat: DIN
Date: 2026-0102-17
Plastics — Determination of residual peroxide — Gas
chromatography method
Plastiques — Détermination du peroxyde résiduel — Méthode par chromatographie en phase gazeuse
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’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
EmailE-mail: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagents . 2
6 Apparatus . 3
7 Preparation of sample . 3
8 Procedure . 3
8.1 Preparation of internal calibration solutions . 3
8.2 Preparation of test solution . 3
8.3 Preparation of the calibration curve . 4
8.4 Determination . 4
9 Calculation . 4
10 Precision . 5
11 Test report . 5
Annex A (informative) Examples of operating conditions . 6
Annex B (informative) Peroxides (DTBP and DBPH) chromatograms . 8
Annex C (informative) Precision and accuracy of the method . 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).
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 61, Plastics, Subcommittee SC 5, Physical-
Chemical Propertieschemical properties.
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
Peroxide has many applications in polymer preparation, such as: used as a degradation agent in the
degradation reaction of ultra-high fluidity polypropylene (PP) and a variety of polymers, as a crosslinking
agent in polyethylene’s (PE) crosslinking reaction, as initiator for free radical polymerization, as a vulcanizing
agent for rubber vulcanization, etc. For health reasons and stable product quality, the content of residual
peroxide in plastics, especially in peroxide-degraded polypropylene (PP) needs to be determined.
Chromatography is the main method for the determination of peroxide.
v
DRAFT International Standard ISO/DIS 8810:2025(en)

Plastics — Determination of residual peroxide — Gas chromatography
method
WARNING — Persons using this document should be familiar with normal laboratory practice. This
document does not purport to address all of the safety problems, if any, associated with its use. It is
the responsibility of the user to establish appropriate safety and health practices and to ensure
compliance withdetermine any applicable national regulatory conditions prior to use.
IMPORTANT — It is absolutely essential that tests conducted in accordance with this document be
carried out by suitably trained staff.
1 Scope
This document specifies a method for the determination of di-tert-butyl peroxide (DTBP) and 2, 5-Dimethyl-
2, 5-di (tert-butylperoxy) hexane (DBPH) in plastics by using gas chromatography.
This document is applicable to the determination of the content of residual peroxides in plastics and their
products, which use peroxides as a degradation agent or crosslinking agent during plastics processing, or as
an additive during polymerization, thereby remaining in degraded polypropylene, crosslinked polyethylene,
polystyrene and other plastics.
NOTE The applicability of this method to other peroxides is possible when the method is validated for each case.
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 648, Laboratory glassware — Single-volume pipettes
ISO 1042, Laboratory glassware — One-mark volumetric flasks
3 Terms and definitions
No terms and definitions are listed in this document.
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4 Principle
The test sample is extracted by ultrasonic bath with tetrahydrofuran or other suitable solvent. After the extract
solution is cooled, the internal standard is added, and the solution is shaken and filtered. The residual
peroxides in the extract solution are determined by gas chromatography (GC) with suitable detection
technique.
5 Reagents
During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and distilled or
demineralized water or water of equivalent purity.
®1 1)
5.1 5.1 Di-tert-butyl peroxide (DTBP), CAS RN . . 110-05-4, minimum of 95 % purity.
®1)
5.2 5.2 2, 5-Dimethyl-2, 5-di (tert-butylperoxy) hexane (DBPH), CAS RN 78-63-7,
minimum of 93 % purity.
5.3 5.3 Solvent, any product which will completely dissolve the internal reference and the target
peroxides (DTBP and DBPH) to give a stable solution, and which meets the following requirements:
— — is inert (does not react with the resin or the internal standard under the test conditions);
— — is compatible with the constituents of the chromatographic column;
— — has a retention time different from those of the peroxides and the internal reference.
Examples of solvents which meet the above-mentioned requirements are:
®1)
— — tetrahydrofuran (THF), CAS RN 109-99-9 (recommended);
®1)
— — toluene, CAS RN 108-88-3;
®1)
— — trichloromethane, CAS RN 67-66-3.
WARNING — The reagents used in this method are toxic. Safety precautions are necessary.
®1)
5.4 5.4 Internal reference substance, Undecane, CAS RN 1120-21-4, analytical grade or higher.
The internal reference substance shall not be present in the test portion matrix. Other compounds may be
used as alternative internal reference substances.
5.5 5.5 Initial calibration solution, 100 mg/l of DTBP and DBPH, each in tetrahydrofuran or other
suitable solvent.
The initial calibration solution should be properly stored at 4 °C to prevent change of concentration. It is
recommended that the solution should be prepared at least every three months.
5.6 5.6 Internal reference solution, 100 mg/l of undecane or others, in tetrahydrofuran or other
suitable solvent.
The internal stock solution should be properly stored at 4 °C to prevent change of concentration. It is
recommended that the solution should be prepared at least every three months.

CAS Registry Number® is a trademark of the American Chemical Society (ACS). This information is given for the
convenience of users of this document and does not constitute an endorsement by ISO of the product named. Equivalent
products may be used if they can be shown to lead to the same results.
1)
CAS Registry Number® is a trademark of the American Chemical Society (ACS). This information is given for the
convenience of users of this document and does not constitute an endorsement by ISO of the product named. Equivalent
products may be used if they can be shown to lead to the same results.

6 Apparatus
6.1 6.1 Gas chromatography (GC), any laboratory chromatograph fitted with a suitable detection.
Examples of the operating conditions are shown in Annex AAnnex A. It is possible to use different procedures
providing it can be verified that they would give the same results.
6.2 6.2 Column, any column with characteristics (length, diameter, stationary phase) which will
ensure separation of the peroxides (DTBP and DBPH), internal standard and solvent is suitable.
Examples of columns are shown in 0Table A.1 and 0Table A.2.
6.3 6.3 Analytical balance, maximum load ≥ 5 mg, accurate to ±0,1 mg.
6.4 6.4 Ultrasonic bath, maximum temperature ≥ 60 °C, accur
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