EN ISO 13164-4:2023 PDF

Overview

EN ISO 13164-4:2023 - Water quality - Radon-222 - Part 4 describes a validated laboratory method for measuring radon-222 (222Rn / Rn-222) activity concentration in non-saline waters using two-phase liquid scintillation counting. The standard is the CEN-adopted version of ISO 13164-4:2023 and supersedes the 2020 edition. It is intended for routine environmental and drinking-water monitoring where typical measurable activity concentrations are above 0.5 Bq·L−1 (using a 10 ml test sample and ~1 h counting time).

Key topics and technical requirements

• Scope and limitations
  • Applicable to non-saline waters; laboratories must verify method validity for untested matrices.
  • Typical detection limit: ~0.5 Bq·L−1 for specified sample volume and counting time.
• Principle
  • Extraction of 222Rn into a scintillation phase followed by two-phase liquid scintillation counting.
• Sampling and sample handling
  • Procedures for sampling with and without on-site source preparation to preserve radon integrity.
• Reagents and apparatus
  • Lists of required reagents, consumables and counting equipment suitable for two-phase liquid scintillation.
• Measurement procedure
  • Calibration source preparation, optimization of counting conditions, determination of detection efficiency, blank preparation and sample measurement.
• Quality assurance / quality control
  • Instrument verification, contamination control, interference checks, method verification and analyst competency requirements.
• Expression of results
  • Calculation of count rates, activity concentration per unit mass, combined uncertainty, decision threshold and detection limit reporting.
• Annex A (informative)
  • Set-up parameters and validation data (counting conditions and examples to meet detection limits for drinking water monitoring).

Practical applications

• Routine monitoring of drinking water and groundwater for radon-222 compliance and risk assessment.
• Environmental surveillance of surface waters and groundwater near uranium-bearing geology or industrial sites.
• Support for regulatory laboratories, accredited testing bodies and research labs performing radioactivity measurements.
• Baseline studies, exposure assessments and investigations following releases from industrial or natural sources.

Who should use this standard

• Water testing laboratories and environmental monitoring services
• Public health and drinking-water regulators
• Accredited radiation measurement laboratories
• Consultants and researchers in hydrogeology, environmental radiochemistry and public health

Related standards

• Other parts of the ISO 13164 series covering radon measurement in water
• ISO/TC 147 (Water quality) and CEN/TC 230 (Water analysis) publications for broader water-quality testing guidance

Keywords: EN ISO 13164-4:2023, radon-222, Rn-222, water quality, two-phase liquid scintillation counting, drinking water monitoring, detection limit, non-saline waters.