EN ISO 20553:2025 PDF

Overview

EN ISO 20553:2025 - "Radiation protection - Monitoring of workers occupationally exposed to a risk of internal contamination with radioactive material" (ISO 20553:2025) specifies minimum requirements for designing programmes to monitor workers at risk of internal contamination. Published by CEN and aligned with the ISO edition, this standard establishes principles for setting compatible goals and requirements for monitoring programmes in occupational radiation protection.

Key topics and technical requirements

The standard defines the scope and core elements of monitoring programmes without prescribing detailed measurement techniques. Major topics include:

• Purposes of monitoring: objectives for routine, special, task-related and confirmatory monitoring.
• Categories of programmes: definitions and use-cases for routine, special, task-related and confirmatory monitoring.
• Quantitative criteria: decision criteria for when and how to monitor occupational intakes.
• Selection of monitoring methods: guidance on suitable in vivo and in vitro methods and criteria for choosing them.
• Required information: data to be collected to design an effective monitoring programme (work tasks, radionuclides, exposure pathways).
• General programme requirements: performance expectations such as detection limits and tolerated uncertainties.
• Measurement frequencies: calculation of measurement intervals using the ICRP Occupational Intakes of Radionuclides (OIR) series.
• Special-case individual monitoring: procedures for actinide intakes, wound intakes and transdermal intakes.
• Quality assurance: programmatic QA elements to ensure reliability of monitoring.
• Documentation and record-keeping: reporting, record retention and worker information requirements.

The standard explicitly excludes radon and its progeny monitoring, detailed measuring procedures, dose interpretation, and biokinetic models for dose conversion.

Practical applications and users

EN ISO 20553:2025 is designed for organizations that manage occupational exposure to radioactive materials, including:

• Radiation protection officers and health physicists
• Employers in nuclear power, research reactors, radiopharmacies, nuclear medicine departments and industrial radiography
• Occupational hygiene and safety teams responsible for programme design and implementation
• Accredited laboratories and in vivo monitoring facilities developing routine or special monitoring services
• Regulators and inspectors establishing compliance expectations

Practical applications include designing routine individual and workplace monitoring programmes, establishing measurement schedules based on ICRP OIR guidance, selecting appropriate bioassay or in vivo techniques, and implementing QA and record-keeping systems to document worker exposures and programme performance.

Related standards

• ISO 20553:2025 (this document; supersedes EN ISO 20553:2017)
• ICRP Occupational Intakes of Radionuclides (OIR) series - used for calculating monitoring frequencies and assessment criteria

EN ISO 20553:2025 helps organizations implement robust, defensible monitoring programmes for internal contamination risk, integrating radiation protection best practices, quality assurance, and regulatory compliance.