FprEN IEC 60544-4:2026

• Status: Not Published
• Publication Date: 03-Jan-2027
• ICS: 17.240 - Radiation measurements
• ICS: 29.035.01 - Insulating materials in general
• Technical Committee: CLC/SR 112 - Evaluation and qualification of electrical insulating materials and systems (to be defined)
• Drafting Committee: IEC/TC 112 - IEC_TC_112
• Current Stage: 5020 - Vote circulated - Formal Approval
• Start Date: 21-Aug-2026
• Due Date: 25-Apr-2025
• Completion Date: 21-Aug-2026
• Ref Project: kSIST FprEN IEC 60544-4:2026 - Electrical insulating materials - Determination of the effects of ionizing radiation - Part 4: Classification system for service in radiation environments

• Revises: EN 60544-4:2003 - Electrical insulating materials - Determination of the effects of ionizing radiation - Part 4: Classification system for service in radiation environments
• Effective Date: 23-Jan-2023

Overview

FprEN IEC 60544-4:2026 focuses on the classification of electrical insulating materials according to their performance and stability when exposed to ionizing radiation. Developed by the International Electrotechnical Commission (IEC), this standard provides a recognized system to guide the selection, qualification, and specification of insulating materials for use in environments where radiation exposure is a critical factor-such as nuclear facilities, irradiation plants, particle accelerators, and medical X-ray equipment.

This document is part of the IEC 60544 series, which addresses the broader topic of evaluating the effects of ionizing radiation on electrical insulating materials. Part 4 specifically establishes a classification framework to help engineers and procurement professionals match materials’ radiation endurance to service conditions.

Key Topics

• Radiation Index:
  The core of this standard is the "radiation index," which quantitatively represents the maximum dose of ionizing radiation a given material can endure while maintaining specified electrical or mechanical properties. The index is based on logarithmic values of absorbed dose (in grays).

• Critical Properties and End-Point Criteria:
  The classification system specifies which properties are critical for different types of polymeric materials. For rigid plastics, flexural stress at maximum load is typically used, while for flexible plastics and elastomers, elongation at break is common. Properties like tensile strength, volume resistivity, and surface resistivity are also considered.

• Service Qualifiers:
  The radiation index includes essential service qualifiers such as:

  • Dose rate at which the material was tested
  • Sample thickness
  • Medium of irradiation (e.g., in air, vacuum)
  • Service temperature

• Testing and Conditions:
  Testing procedures must comply with referenced standards to ensure consistent, reliable outcomes. The test conditions simulate real service environments, considering variables such as temperature, atmosphere, and irradiation type.

• Material Identification:
  The standard requires that the source, type, and specific properties of the insulated material be documented to prevent misclassification, as similar materials may behave differently based on additives and structure.

Applications

• Nuclear Facilities:
  FprEN IEC 60544-4:2026 is vital for specifying insulation in reactors and fuel processing plants, where exposure to high doses of ionizing radiation is routine.

• Radiation Processing and Research:
  Insulating materials in irradiation facilities or particle accelerators must reliably withstand radiation without compromising safety or function.

• Medical and Industrial X-ray Equipment:
  Devices used in diagnostic imaging or non-destructive testing require insulation that meets defined thresholds for radiation endurance.

• Equipment Procurement and Specification:
  The classification system provides a common language and benchmarks for manufacturers, engineers, and buyers, supporting informed decisions and accurate procurement documentation.

• Material Qualification and Comparison:
  By providing clear parameters for classification, the standard assists in qualifying new insulating materials for use or in comparing alternatives for specific applications.

Related Standards

Adherence to FprEN IEC 60544-4:2026 often requires consultation of related standards, including:

• IEC 60544-1: Radiation interaction and dosimetry overview
• IEC 60544-2: Procedures for irradiation and test
• IEC TS 61244 Series: Long-term radiation ageing in polymers
• IEC 62631-3-1 and -3-2: Methods for determining resistive properties of insulating materials
• IEC 60212: Standard conditions for testing solid insulating materials
• ISO standards for measurement of mechanical and electrical properties, including ISO 178, ISO 527, ISO 37, and ISO 815

Practical Value

Implementation of the classification system for electrical insulating materials in radiation environments ensures enhanced safety, predictable performance, and compliance with international best practices. By following FprEN IEC 60544-4:2026, organizations can reduce risk, improve specification accuracy, and facilitate the global trade of electrical insulating materials fit for radiation service.

SLOVENSKI STANDARD
oSIST prEN IEC 60544-4:2025
01-december-2025
Električni izolacijski materiali - Ugotavljanje učinkov ionizirnega sevanja - 4. del:
Klasifikacijski sistem za uporabo v okoljih s sevanjem
Electrical insulating materials - Determination of the effects of ionizing radiation - Part 4:
Classification system for service in radiation environments
Elektroisolierstoffe - Bestimmung der Wirkung ionisierender Strahlung - Teil 4:
Klassifikationssystem für den Einsatz unter Strahlung
Matériaux isolants électriques - Détermination des effets des rayonnements ionisants -
Partie 4: Système de classification pour l'utilisation dans un environnement sous
rayonnement
Ta slovenski standard je istoveten z: prEN IEC 60544-4:2025
ICS:
17.240 Merjenje sevanja Radiation measurements
29.035.01 Izolacijski materiali na Insulating materials in
splošno general
oSIST prEN IEC 60544-4:2025 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN IEC 60544-4:2025
oSIST prEN IEC 60544-4:2025
112/696/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 60544-4 ED3
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2025-10-10 2026-01-02
SUPERSEDES DOCUMENTS:
112/680/CD, 112/694/CC
IEC TC 112 : EVALUATION AND QUALIFICATION OF ELECTRICAL INSULATING MATERIALS AND SYSTEMS
SECRETARIAT: SECRETARY:
Germany Mr Bernd Komanschek
OF INTEREST TO THE FOLLOWING COMMITTEES: HORIZONTAL FUNCTION(S):
SC 45A
ASPECTS CONCERNED:
Electricity transmission and distribution,Safety
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft for Vote
(CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
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This document is still under study and subject to change. It should not be used for reference purposes.
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Recipients of this document are invited to submit, with their comments, notification of any relevant “In Some Countries” clauses to
be included should this proposal proceed. Recipients are reminded that the CDV stage is the final stage for submitting ISC clauses.
(SEE AC/22/2007 OR NEW GUIDANCE DOC).

TITLE:
Electrical insulating materials – Determination of the effects of ionizing radiation – Part 4: Classification
system for service in radiation environments

PROPOSED STABILITY DATE: 2029
NOTE FROM TC/SC OFFICERS:
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oSIST prEN IEC 60544-4:2025
Link to Committee Draft for Vote (CDV) online document:

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oSIST prEN IEC 60544-4:2025
IEC CDV 60544-4 © IEC 2025
CONTENTS
FOREWORD . 2
INTRODUCTION . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Classification system . 6
4.1 Definition of radiation index . 6
4.2 Dose rate . 6
4.3 Critical properties . 7
4.4 Temperatures . 7
4.5 Additional considerations . 7
5 Designation of radiation index and special service qualifiers . 8
5.1 Radiation index . 8
5.2 Radiation index with qualifications . 8
5.3 Examples . 8
Bibliography . 11

Table 1 – Critical properties and end-point criteria to be considered in evaluating
the classification of insulating materials in radiation environments . 9
Table 2 – Values for radiation index . 9

oSIST prEN IEC 60544-4:2025
IEC CDV 60544-4 © IEC 2025
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Electrical insulating materials –
Determination of the effects of ionizing radiation –
Part 4: Classification system for service in radiation environments

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for
standardization comprising all national electrotechnical committees (IEC National Committees).
The object of IEC is to promote international co-operation on all questions concerning
standardization in the electrical and electronic fields. To this end and in addition to other
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any personal injury, property damage or other damage of any nature whatsoever, whether direct
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of, or reliance upon, this IEC Publication or any other IEC Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced
publications is indispensable for the correct application of this publication.
9) IEC draws attention to the possibility that the implementation of this document may involve
the use of (a) patent(s). IEC 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,
IEC had not notice of (a) patent(s), which may be required to implement this document.
oSIST prEN IEC 60544-4:2025
IEC CDV 60544-4 © IEC 2025
However, implementers are cautioned that this may not represent the latest information, which
may be obtained from the patent database available at https://patents.iec.ch and
www.iso.org/patents . IEC shall not be held responsible for identifying any or all such patent
rights.
IEC 60544-4 has been prepared by IEC technical committee TC 112: Evaluation and
qualification of electrical insulating materials and systems. It is an International Standard.
This third edition cancels and replaces the second edition published in 2003. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
– The purpose of the revision was to update the list of test methods and associated references
in Part 4.
The text of this International Standard is based on the following documents:
Draft Report on voting
112/XXX/XX 112/XXX/XX
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English [change
language if necessary].
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
IEC 60544 consists of the following parts, under the general title Electrical insulating materials
– Determination of the effects of ionizing radiation:
Part 1:  Radiation interaction and dosimetry
Part 2:  Procedures for irradiation and test
Part 3:  (now incorporated into Part 2)
Part 4:  Classification system for service in radiation environments
Part 5:  Procedures for assessment of ageing in service
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
– reconfirmed,
– withdrawn, or
– revised.
oSIST prEN IEC 60544-4:2025
IEC CDV 60544-4 © IEC 2025
INTRODUCTION
Organic insulating materials occupy a role of major significance in electrical technology. They
rank with metals and ceramics as the principal category of materials used in the construction
of components in this field. Of all materials, organics are amongst those that are most sensitive
to the effects of radiation, and the response varies widely for different materials. Thus, when
selecting insulating materials for specific service applications in radiation environments,
information on the radiation tolerance of the candidate materials is required. The purpose of
this part of IEC 60544 is to define an internationally recommended classification system to
categorize the radiation endurance of insulating materials for such applications.
This standard is the fourth in a series dealing with the effect of ionizing radiation on insulating
materials. IEC 60544-1 constitutes an introduction dealing very broadly with the problems
involved in evaluating radiation effects. It also provides a guide to dosimetry terminology,
several methods of determining exposure and absorbed dose, and methods of calculating
absorbed dose in any specific material from the dosimetry method applied.
IEC 60544-2 describes procedures for maintaining seven different types of exposure conditions
during the irradiation. It also specifies the controls that are maintained over these conditions so
that when test results are reported, reliable comparisons of material performances can be
obtained. In addition, it defines certain important irradiation conditions and the test procedures
to be used for property change determinations and the corresponding end-point criteria.
IEC 60544-3 has been incorporated into the second edition of IEC 60544-2.
IEC 60544-5 deals with procedures for the assessment of ageing in service.
Note from IEC: the following item is listed in the bibliography but not cited in the text. Please
find a suitable place to cite it in the text to justify its inclusion in the bibliography.
IEC 60167, Methods of test for the determination of the insulation resistance of solid insulating
materials
oSIST prEN IEC 60544-4:2025
IEC CDV 60544-4 © IEC 2025
1 Scope
This part of IEC 60544 provides a classification system that serves as a guide for the selection
and indexing of insulating materials intended to serve in the radiation environment of nuclear
reactor facilities, reactor fuel-processing facilities, irradiation facilities, particle accelerators,
and X-ray apparatus.
The classification system provides a set of parameters defining the utility of the three types of
polymeric materials (rigid plastics, flexible plastics, elastomers) for use in devices which are
exposed to ionizing radiation.
This part of IEC 60544 forms the basis for a quantitative statement of the suitability of such
materials for radiation environments and therefore provides a guide for material specifications
and for procurement agreements between suppliers and users.
2 Normative references
The following documents are referred to in the text in such a
...