ISO/ASTM 51539:2023

Guidance for use of radiation-sensitive indicators

This document covers procedures for using radiationsensitive indicators (referred to hereafter as indicators) in radiation processing. These indicators may be labels, papers, inks or packaging materials which undergo a visual change when exposed to ionizing radiation (1-5). The purpose for using indicators is to determine visually whether or not a product has been irradiated, rather than to measure different dose levels. Indicators are not dosimeters and should not be used as a substitute for proper dosimetry. Information about dosimetry systems for radiation processing is provided in other ASTM and ISO/ASTM documents (see ISO/ASTM Guide 51261). This document does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this document to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. This document was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

Lignes directrices pour l'utilisation d'indicateurs sensibles aux rayonnements

General Information

• Status: Published
• Publication Date: 15-May-2023
• ICS: 17.240 - Radiation measurements
• Technical Committee: ISO/TC 85 - Nuclear energy, nuclear technologies, and radiological protection
• Drafting Committee: ISO/TC 85 - Nuclear energy, nuclear technologies, and radiological protection
• Current Stage: 9599 - Withdrawal of International Standard
• Start Date: 04-Apr-2025
• Completion Date: 30-Oct-2025

Relations

• Revises: ISO/ASTM 51539:2013 - Guide for use of radiation-sensitive indicators
• Effective Date: 28-Aug-2021

Overview

ISO/ASTM 51539:2023 provides comprehensive guidance on the use of radiation-sensitive indicators in radiation processing. These indicators, including labels, papers, inks, or packaging materials, exhibit a visible change upon exposure to ionizing radiation. The standard defines procedures for their proper application to visually confirm whether a product has undergone irradiation. It emphasizes that such indicators serve as qualitative tools, not as dosimeters, and should not replace formal dosimetry methods for dose measurement.

This international standard was developed under ISO and ASTM collaboration following the World Trade Organization (WTO) Technical Barriers to Trade (TBT) Committee principles, ensuring global applicability and harmonization in radiation processing industries.

Key Topics

• Purpose of Indicators
  Radiation-sensitive indicators are designed to provide a visual confirmation of product irradiation. They facilitate differentiation between irradiated and non-irradiated items by displaying a color or appearance change under standard viewing conditions.

• Non-Dosimetric Nature
  These indicators do not measure absorbed dose levels and are not suitable as substitutes for quantitative dosimetry systems. Proper dose assessment requires specialized systems detailed in related standards such as ISO/ASTM Guide 51261.

• Selection Criteria
  Indicators must be chosen based on suitability for the radiation type, dose range, environmental conditions, and product characteristics. Factors such as response threshold, stability under irradiation, and adherence to product surfaces are critical for effective use.

• Application Guidelines
  The standard advises using indicators to verify process loads, support segregation of irradiated vs. non-irradiated products, and assist in locating process interruptions. For multi-sided irradiation processes, indicators can aid by being placed on surfaces facing radiation sources to assure proper exposure.

• Limitations and Environmental Effects
  Users must recognize indicators’ limitations. Environmental factors like heat, UV light, and gases from irradiation may alter indicator appearance, potentially causing false positives or negatives. Therefore, their use is most effective within controlled irradiation facilities, with manufacturer guidelines on handling and storage strictly followed.

• Safety and Compliance Responsibility
  The standard does not cover all possible safety concerns associated with indicator use. Users must ensure compliance with health, safety, environmental practices, and regulatory requirements independently.

Applications

• Radiation Processing Verification
  Indicators serve as a practical visual check to confirm if products have been exposed to ionizing radiation during sterilization, food processing, or material modification processes.

• Quality Control Support
  By showing a visible change after irradiation, indicators aid in quality assurance protocols, marking batches or individual items for easy identification, especially in complex processing lines.

• Process Monitoring and Troubleshooting
  They are useful to detect irradiation interruptions and help isolate affected zones, minimizing wasted product and ensuring process integrity.

• Facility Workflow Management
  Indicators facilitate sorting and handling within radiation facilities by quickly segregating irradiated materials from unprocessed ones.

• Education and Training
  The standard provides a foundation for training operators and quality managers on the proper use and limitations of radiation-sensitive indicators in industrial environments.

Related Standards

• ISO/ASTM Guide 51261 – Calibration of Routine Dosimetry Systems for Radiation Processing
• ISO/ASTM 51608 – Dosimetry for X-ray (Bremsstrahlung) Facilities
• ISO/ASTM 51649 – Dosimetry for Electron Beam Facilities
• ISO/ASTM 51702 – Dosimetry for Gamma Facilities
• ISO/ASTM 51939 – Blood Irradiation Dosimetry Practices
• ISO/ASTM 51940 – Dosimetry Guide for Sterile Insect Release Programs

These interconnected standards complement ISO/ASTM 51539 by providing detailed quantitative dosimetry methods essential for dose measurement and control in radiation processing.

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Keywords: radiation-sensitive indicator, radiation processing, ionizing radiation, irradiation verification, radiation dosimetry, electron beam, gamma radiation, X-ray irradiation, radiation monitoring, process control indicators.

Standards Content (Sample)

INTERNATIONAL ISO/ASTM
STANDARD 51539
Fourth edition
2023-05
Guidance for use of radiation-sensitive
indicators
Lignes directrices pour l'utilisation d'indicateurs sensibles aux
rayonnements
Reference number
© ISO/ASTM International 2023
© ISO/ASTM International 2023
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. In the United States, such requests should be sent to ASTM International.
ISO copyright office ASTM International
CP 401 • Ch. de Blandonnet 8 100 Barr Harbor Drive, PO Box C700
CH-1214 Vernier, Geneva West Conshohocken, PA 19428-2959, USA
Phone: [phone] Phone: [phone]
Fax: [phone]
Email: [e-mail] Email: [e-mail]
Website: www.iso.org Website: www.astm.org
Published in Switzerland
ii © ISO/ASTM International 2023 – All rights reserved

Contents Page
1 Scope. 1
2 Referenced documents. 1
3 Terminology. 1
4 Significance and use. 2
5 Selection of indicators. 2
6 Application. 2
7 Limitations of use. 2
8 Keywords. 2
© ISO/ASTM International 2023 – All rights reserved iii

ISO/ASTM 51900:2023(E)
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 ASTM Committee E61, Radiation processing (as ASTM E1539-93), and
drafted in accordance with its editorial rules. It was assigned to Technical Committee ISO/TC 85, Nuclear
energy, nuclear technologies and radiological protection.
This fourth edition cancels and replaces the third edition (ISO/ASTM 51939:2013) which has been
technically revised.
The main changes are as follows:
— Editorial corrections throughout the document.
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/ASTM International 2023 – All rights reserved

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Standard Guidance for
Use of Radiation-Sensitive Indicators
This standard is issued under the fixed designation ISO/ASTM 51539; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision.
1. Scope 2.2 ISO/ASTM Standards:
51261Practice for Calibration of Routine Dosimetry Sys-
1.1 This document covers procedures for using radiation-
tems for Radiation Processing
sensitive indicators (referred to hereafter as indicators)in
51608Practice for Dosimetry in an X-ray (Bremsstrahlung)
radiation processing. These indicators may be labels, papers,
Facility for Radiation Processing at Energies between 50
inks or packaging materials which undergo a visual change
2 keV and 7.5 MeV
when exposed to ionizing radiation (1-5).
51649Practice for Dosimetry in an Electron Beam Facility
1.2 Thepurposeforusingindicatorsistodeterminevisually
forRadiationProcessingatEnergiesbetween300keVand
whether or not a product has been irradiated, rather than to
25 MeV
measure different dose levels.
51702Practice for Dosimetry in a Gamma Facility for
Radiation Processing
1.3 Indicators are not dosimeters and should not be used as
51939Practice for Blood Irradiation Dosimetry
a substitute for proper dosimetry. Information about dosimetry
51940Guide for Dosimetry for Sterile Insect Release Pro-
systems for radiation processing is provided in other ASTM
grams
and ISO/ASTM documents (see ISO/ASTM Guide 51261).
2.3 International Commission on Radiation Units and Mea-
1.4 This standard does not purport to address all of the 4
surements (ICRU) Reports:
safety concerns, if any, associated with its use. It is the
ICRU Report 85Fundamental Quantities and Units for
responsibility of the user of this standard to establish appro-
Ionizing Radiation
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
3. Terminology
1.5 This international standard was developed in accor-
3.1 Definitions:
dance with internationally recognized principles on standard-
3.1.1 dosimetry system—interrelated elements used for de-
ization established in the Decision on Principles for the
termining absorbed dose, consisting of dosimeters, measure-
Development of International Standards, Guides and Recom-
ment instruments and their associated reference standards, and
mendations issued by the World Trade Organization Technical
procedures for the system’s use.
Barriers to Trade (TBT) Committee.
3.1.2 indicator—see radiation-sensitive indicator.
3.1.3 process load—volume of material with a specified
2. Referenced documents
product loading configuration irradiated as a single entity.
2.1 ASTM Standards:
3.1.4 radiation-sensitive indicator—material such as coated
E170Terminology Relating to Radiation Measurements and
orimpregnatedadhesive-backedsubstrate,ink,coatingorother
Dosimetry
materials which may be affixed to or printed on the process
E3083Terminology Relating to Radiation Processing: Do-
loads, and which undergoes a visual change when exposed to
simetry and Applications
ionizing radiation.
3.1.4.1 Discussion—This visual change may be as observed
withtheunaidedeyeorwithaneyeaidsuchasanopticalfilter.
ThisdocumentisunderthejurisdictionofASTMCommitteeE61onRadiation
3.1.4.2 Discussion—In the past, radiation-
...