prEN ISO 13164-1

• Abstract:

  ISO 13164-1:2013 gives general guidelines for sampling, packaging, and transporting of all kinds of water samples, for the measurement of the activity concentration of radon-222.; The test methods fall into two categories: a) direct measurement of the water sample without any transfer of phase (see ISO 13164‑2); b) indirect measurement involving the transfer of the radon-222 from the aqueous phase to another phase (see ISO 13164‑3).; The test methods can be applied either in the laboratory or on site.; The laboratory is responsible for ensuring the suitability of the test method for the water samples tested.

• Status: Not Published
• Publication Date: 07-Nov-2027
• ICS: 13.060.60 - Examination of physical properties of water
• ICS: 17.240 - Radiation measurements
• Technical Committee: CEN/TC 230 - Water analysis
• Drafting Committee: CEN/TC 230 - Water analysis
• Current Stage: 4060 - Closure of enquiry - Enquiry
• Start Date: 03-Jul-2026
• Completion Date: 03-Jul-2026
• Ref Project: oSIST prEN ISO 13164-1:2026 - Water quality - Radon-222 - Part 1: General principles (ISO/DIS 13164-1:2026)

• Revises: EN ISO 13164-1:2020 - Water quality - Radon-222 - Part 1: General principles (ISO 13164-1:2013, Correction version 2013-11-15)
• Effective Date: 05-Nov-2024

Overview

prEN ISO 13164-1:2026 sets out the general principles for sampling, packaging, and transporting water samples for the accurate measurement of radon-222 activity concentration. Developed by CEN and aligned with ISO guidance, this draft standard applies to all types of water-including drinking water, groundwater, surface waters, and industrial waters. It establishes key requirements and recommendations for laboratory and field measurements of radon-222, supporting compliance with health and environmental regulations.

Radon-222 is a naturally occurring radioactive gas, present in various water sources due to geological and environmental factors. Its monitoring is essential because elevated levels in water may pose radiation hazards to human health, especially when such water is used for drinking or domestic purposes.

Key Topics

• Sampling Methods:
  • Provides protocols for representative sampling, container selection, and labelling to minimize radon loss and contamination.
  • Covers discrete and continuous sampling, with specific steps for sampling from taps, stagnant waters, and flowing sources.
• Packaging and Transportation:
  • Specifies the use of air-tight, radon-impermeable containers, proper sealing, and shock-resistant packaging.
  • Recommends rapid transport and cool storage, with analysis ideally completed within 48 hours of collection.
• Test Sample Preparation:
  • Outlines techniques such as degassing (to transfer radon to air phase), permeation (using selective membranes), and liquid extraction.
• Measurement Approaches:
  • Categorizes methods into:
    • Direct measurement (analyzing water samples without phase transfer, detailed in ISO 13164-2).
    • Indirect measurement (requiring transfer of radon to another phase, detailed in ISO 13164-3).
  • Discusses detection principles including gamma spectrometry, scintillation counting (ZnS(Ag)), air ionization, semiconductor alpha-detection, and liquid scintillation.
• Quality Assurance:
  • Emphasizes the importance of method suitability, regular calibration, equipment verification, and adherence to quality control protocols.

Applications

Adhering to prEN ISO 13164-1:2026 ensures reliable results in:

• Drinking Water Monitoring: Ensuring radon-222 levels meet regulatory limits to protect public health.
• Environmental Surveillance: Assessing radon in rivers, lakes, and groundwater for geochemical studies or environmental impact assessments.
• Industrial and Process Water Testing: Monitoring water used in food production, pharmaceuticals, and other sectors where water quality is critical.
• Regulatory Compliance: Satisfying national or international requirements on radiation safety in water, including European Council Directive 2013/51/EURATOM.
• Emergency Response: Rapid assessment of potential contamination after industrial incidents or natural events impacting water sources.

Related Standards

The general principles outlined in prEN ISO 13164-1:2026 reference and complement several key standards for water quality and radioactivity measurement:

• ISO 13164-2: Specifies the direct gamma-spectrometric method for radon-222 in water.
• ISO 13164-3: Details indirect measurement methods involving radon transfer between phases.
• ISO 5667-1 / ISO 5667-3: Provide comprehensive guidance on water sampling, preservation, and handling.
• ISO 10703: Describes high-resolution gamma spectrometry for waterborne radionuclides.
• ISO/IEC 17025: Sets general requirements for testing and calibration laboratory competence.
• Other citations: Standards on calculation of measurement limits and terminology (e.g., ISO 80000-10).

Applying this standard promotes best practices in radon-222 water testing, supports health risk minimization, and enables organizations to respond effectively to regulatory and environmental demands.

SLOVENSKI STANDARD
01-junij-2026
Kakovost vode - Radon Rn-222 - 1. del: Splošna načela (ISO/DIS 13164-1:2026)
Water quality - Radon-222 - Part 1: General principles (ISO/DIS 13164-1:2026)
Wasserbeschaffenheit - Radon-222 - Teil 1: Grundlagen (ISO/DIS 13164-1:2026)
Qualité de l'eau - Radon 222 - Partie 1: Principes généraux (ISO/DIS 13164-1:2026)
Ta slovenski standard je istoveten z: prEN ISO 13164-1
ICS:
13.060.60 Preiskava fizikalnih lastnosti Examination of physical
vode properties of water
17.240 Merjenje sevanja Radiation measurements
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 13164-1
ISO/TC 147/SC 3
Water quality — Radon-222 —
Secretariat: AFNOR
Part 1:
Voting begins on:
General principles 2026-04-10
Voting terminates on:
Qualité de l'eau — Radon 222 —
2026-07-03
Partie 1: Principes généraux
ICS: 17.240; 13.060.60; 13.280
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.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
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 13164-1:2026(en)
DRAFT
ISO/DIS 13164-1:2026(en)
International
Standard
ISO/DIS 13164-1
ISO/TC 147/SC 3
Water quality — Radon-222 —
Secretariat: AFNOR
Part 1:
Voting begins on:
General principles
2026-04-10
Voting terminates on:
Qualité de l'eau — Radon 222 —
2026-07-03
Partie 1: Principes généraux
ICS: 17.240; 13.060.60; 13.280
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.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2026
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
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
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
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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 13164-1:2026(en)
ii
ISO/DIS 13164-1:2026(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols . 4
5 Principle . 5
6 Sampling . 6
7 Transportation and storage . 6
8 Test sample preparation . 8
8.1 Degassing techniques .8
8.2 Permeation technique .9
8.3 Liquid extraction technique .9
9 Detection techniques . 9
9.1 Gamma-spectrometry .9
9.2 Silver-activated zinc sulfide, ZnS(Ag), scintillation .9
9.3 Air ionization .9
9.4 Semiconductor (alpha-detection) .10
9.5 Liquid scintillation .10
10 Measurement methods . 10
10.1 General .10
10.2 Gamma-spectrometry method . .10
10.3 Emanometric method .10
10.4 Liquid scintillation counting methods (LSC). 12
10.5 Permeation method . 12
11 Calibration .12
12 Quality assurance and quality control programme .12
12.1 General . 12
12.2 Influence quantities . 12
12.3 Instrument verification . 13
12.4 Method verification . 13
12.5 Demonstration of analyst capability . . 13
13 Expression of results .13
14 Test report .13
Annex A (informative) Radon and its decay products in water .15
Annex B (informative) Examples of data record forms . 19
Bibliography .21

iii
ISO/DIS 13164-1:2026(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 147, Water Quality, Subcommittee SC 3,
Radioactivity measurements.
This second edition cancels and replaces the first edition (ISO 13164-1:2013), which has been technically
revised.
The main changes are as follows:
— Introduction
— Test report
— References
A list of all parts in the ISO 13164 series can be found on the ISO website.
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 13164-1:2026(en)
Introduction
Radionuclides are present throughout the environment; thus, water bodies (e.g. surface waters, ground
waters, sea waters) contain radionuclides, which can be of either natural or anthropogenic origin:
3 14 40
— naturally occurring radionuclides, including H, C, K and those originating from the thorium and
210 210 222 226 228 227 232 231 234 238
uranium decay series, in particular Pb, Po, Rn, Ra, Ra, Ac, Th, Pa, U, and U
can be found in water bodies due to either natural processes (e.g., desorption from the soil, runoff by rain
water) or released from technological processes involving naturally occurring radioactive materials (e.g.
mining, mineral processing, oil, gas and production, water treatment and the production and the use of
phosphate fertilisers);
55 59 63 90 99
— anthropogenic radionuclides such as Fe, Ni, Ni, Sr, Tc, transuranic elements (Np, Pu, Am,
60 137
and Cm) and some gamma emitting radionuclides such as Co and Cs can also be found in natural
waters. Small quantities of anthropogenic radionuclides can be discharged from nuclear facilities to the
environment as a result of authorized routine releases. The radionuclides present in liquid effluents
[1]
are usually controlled before being discharged to the environment and water bodies. Anthropogenic
radionuclides used in medical and industrial applications can be released to the environment after use.
Anthropogenic radionuclides are also found in waters due to the contamination from fallout resulting
above-ground nuclear detonations and accidents such as those that occurred at the Chornobyl and
Fukushima nuclear facilities.
Radionuclide activity concentrations in water bodies can vary according to local geological characteristics
and climatic conditions and can be locally and temporally enhanced by releases from nuclear facilities
[2][3]
during planned, existing, and emergency exposure situations . Some drinking water sources can thus
contain radionuclides at activity concentrations that could present a human health risk. The World Health
[4]
Organization (WHO) recommends to routinely monitor radioactivity in drinking waters and to take
proper actions when needed to minimize the health risk.
National regulations usually specify the activity concentration limits that are authorized in drinking waters,
water bodies, and liquid effluents to be discharged to the environment. These limits can vary for planned,
existing, and emergency exposure situations. The WHO does not have a current recommended specific
activity concentration limit for radon in water as radon exposure through indoor air is considered a more
[4]
pressing concern. In Europe, the implementation of European Council Directive 2013/51/EURATOM
on October 22, 2013, establishes a radon concentration limit of 100 Bq·l-1 and that analytical methods
achieve a 10 Bq·l-1 limit of detection. Compliance with such limits is assessed by measuring radioactivity in
water samples and by comparing the results obtained, with their associated uncertainties, as specified by
[5] [6]
ISO/IEC Guide 98-3 and ISO 5667-20 .
This document contains method to support laboratories which need to determine Rn in water samples.
The method described in this document can be used for various types of waters (see Clause 1). Minor
modifications such as sample volume and counting time can be made if needed to ensure that the
characteristic limit, decision threshold, detection limit, and uncertainties are below the required limits.
This can be done for several reasons such as emergency situations, lower national guidance limits, and
operational requirements.
v
DRAFT International Standard ISO/DIS 13164-1:2026(en)
Water quality — Radon-222 —
Part 1:
General principles
WARNING — Persons using this document should be familiar with normal laboratory practices. 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
the applicability of any other restrictions.
IMPORTANT — It is absolutely essential that tests conducted in accordance with this document be
carried out by suitably qualified staff.
1 Scope
This part of ISO 13164 gives general guidelines for sampling, packaging, and transporting of all kinds of
water samples, for the measurement of the activity concentration of Rn.
The test methods fall into two categories:
[7]
a) direct measurement of the water sample without any transfer of phase (see ISO 13164-2 );
b) indirect measurement involving the transfer of the Rn from the aqueous phase to another phase (see
[8] [9]
ISO 13164-3 and 13164-4 ).
The test methods can be applied either in the laboratory or on-site.
The laboratory is responsible for ensuring the suitability of the test method for the water samples tested.
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 5667-1, Water quality — Sampling — Part 1: Guidance on the design of sampling programmes and sampling
techniques
ISO 5667-3, Water quality — Sampling — Part 3: Preservation and handling of water samples
ISO 10703, Water quality — Gamma-ray emitting radionuclides — Test method using high resolution gamma-
ray spectrometry
ISO 11929-1, Determination of the characteristic limits (decision threshold, detection limit and limits of
the coverage interval) for measurements of ionizing radiation — Fundamentals and application — Part 1:
Elementary applications
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
ISO 80000-10, Quantities and units — Part 10: Atomic and nuclear physics

ISO/DIS 13164-1:2026(en)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 80000-10 and the following apply.
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/
3.1.1
activity
number of spontaneous nuclear disintegrations occurring in a given quantity of material during a suitably
small interval of time divided by that interval of time
[10]
[SOURCE: ISO 921:1997, 23 ]
3.1.2
activity concentration in water
activity per volume of water
Note 1 to entry: The activity concentration in water is expressed in becquerels per litre.
3.1.3
activity concentration in air
activity per volume of air following the degassing phase
Note 1 to entry: The activity concentration in air is expressed in becquerels per cubic metre.
3.1.4
test sample
part of the total sample subjected to analysis
3.1.5
Bunsen coefficient
volume of a gas dissolved at standard temperature (273,15 K) and standard partial pressure (0,1 MPa)
divided by the volume of the solvent at a temperature, T, and standard pressure (0,1 MPa)
Note 1 to entry: Adapted from Reference [11], p. 239.
Note 2 to entry: Modern practice recommends that gas solubility be expressed as molality, mole fraction or mole ratio
(see Reference [11]). However, in many studies dealing with radon measurement in water, the Bunsen coefficient
appears frequently.
Note 3 to entry: The solubility of radon in water increases as the water temperature decreases (see Annex A).
3.1.6
continuous measurement of radon in water
measurement of the radon activity concentration of continuous samples at a given sampling point in the
body of water
Note 1 to entry: This form of analysis is used to monitor variations in the activity concentration of radon in the water
at the sampling point over time.
3.1.7
continuous sampling
process whereby samples are taken continuously from a body of water
[13]
[SOURCE: ISO 6107-2:2006, 32, modified]
3.1.8
degassing
transfer of dissolved radon from water to air, usually by means of a physical process

ISO/DIS 13164-1:2026(en)
3.1.9
direct in-situ measurement
automatic analysis system in which at least the measurement probe is immersed in the body of water
3.1.10
discrete sample
localized discrete sample
single sample taken from a body of water at a random time or place
3.1.11
dissolution
mixing of two phases with the formation of one new homogeneous phase
3.1.12
drinking water
potable water
water of a quality suitable for drinking purposes
[12]
[SOURCE: ISO 6107-1:2004, 30]
3.1.13
groundwater
water which is held in, and can usually be recovered from, an underground formation
[12]
[SOURCE: ISO 6107-1:2004, 41, modified]
3.1.14
intermittent sampling
process whereby discrete samples are taken from a body of water
3.1.15
mains water
water fed from a drinking water treatment station, spring or borehole into a distribution system or reservoir
3.1.16
Ostwald coefficient
volume of a gas dissolved at a given temperature and pressure divided by the volume of the solvent at the
same temperature and pressure
Note 1 to entry: Adapted from Reference [11], p.256.
Note 2 to entry: Modern practice recommends that gas solubility be expressed as molality, mole fraction or mole ratio
(see Reference [11]). However, in many studies dealing with radon measurement in water, the Ostwald coefficient
appears frequently.
Note 3 to entry: The solubility of radon in a liquid increases as the liquid temperature decreases (see Annex A).
3.1.17
radon transport by permeation
transfer of radon from one medium to another across a third homogeneous medium (membrane)
3.1.18
raw water
water which has received no treatment whatsoever, or water entering a plant for treatment or further
treatment
[12]
[SOURCE: ISO 6107-1:2004, 59]
3.1.19
reservoir
construction, partially or wholly man-made, for storage or regulation and control of water
[13]
[SOURCE: ISO 6107-2:2006, 107, modified]

ISO/DIS 13164-1:2026(en)
3.1.20
surface water
water which flows over, or rests on, the surface of a land mass
[12]
[SOURCE: ISO 6107-1:2004, 74]
3.1.21
sample
portion, ideally representative, removed from a specified body of water, either discretely or continuously,
for the purpose of examination of various defined characteristics
[8]
[SOURCE: ISO 6107-2:2006, 111]
3.1.22
sampling
process of removing a portion, intended to be representative, of a body of water for the purpose of
examination of various defined characteristics
[13]
[SOURCE: ISO 6107-2:2006, 114]
3.1.23
sampling point
precise position within a sampling location from which samples are taken
[13]
[SOURCE: ISO 6107-2:2006, 117]
3.1.24
sampling zone
extent of a body of water over which samples are taken
3.1.25
short-lived Rn decay products
222 218
radionuclides with a half-life <1 h produced by the decay of radon-222 ( Rn), namely polonium-218 ( Po),
214 214 214
lead-214 ( Pb), bismuth-214 ( Bi), and polonium-214 ( Po)
Note 1 to entry: See Figure 1.
3.1.26
spot measurement of radon in water
measurement of the radon activity concentration in a discrete water sample carried out either immediately
or after a known delay
Note 1 to entry: The result obtained is only representative of the time the sample was taken.
3.1.27
transfer
displacement or transport of radon from one phase to another
4 Symbols
For the purpose of this document, the symbols given in ISO 80000-10 and the following apply.
A Activity of each radionuclide in calibration source, at the calibration time Bq
-3
c activity concentration in air following degassing Bq·m
−1
c activity concentration in water Bq·l
A
−1
∗
decision threshold Bq·l
c
A
ISO/DIS 13164-1:2026(en)
−1
#
detection limit Bq·l
c
A
−1

lower and upper limits of the confidence interval Bq·l
cc,
AA
−1
c activity concentration in a liquid Bq·l
l
L Ostwald coefficient
temperature of water sample °C
T
HO
U expanded uncertainty calculated by U = k·u( ) with k = 2
-1
u(c ) standard uncertainty associated with the measurement result Bq l
A
V volume of the test sample l
α Bunsen coefficient
5 Principle
226 238
Rn-222 is a radioactive gas produced by the decay of Ra, which is one of the decay products of the U
that is naturally present in the Earth’s crust (see Annex A). The decay of Rn proceeds through a series of
non-volatile radioactive elements resulting in stable Pb(see Figure 1) (Reference [14]).
Figure 1 — Uranium-238 and its decay products
A large number of methods are available to measure the activity concentration of Rn in water.
The measurement of the activity concentration of Rn in water involves the following operations:
— collection of a representative sample of the water at time t in a suitable container;
— storage and the transportation of the sample, when the measurement is carried out in a laboratory;

ISO/DIS 13164-1:2026(en)
— test sample preparation by transferring the radon dissolved in the water to another phase, when needed
by the detection techniques (emanometric or a liquid scintillation counting);
— determination of the radon activity concentration in the water using a variety of detection techniques
directly or through its decay products (see Figure 2).
The methods specified in the different parts of this International Standard are applicable to all types of water
(see Table 2), and the method is selected according to the purpose of the measurement, phenomenological
observation or radiological impact assessment taking into account the level of the radon activity
concentration expected in the raw sample.
6 Sampling
Sampling shall be carried out in accordance with ISO 5667-1 and ISO 5667-3.
The sampling conditions shall comply with ISO 5667-1, and shall also satisfy those conditions specified in
Table 1 in order to minimize as far as possible any exchange with the atmosphere and to maintain the radon
in solution in the water sample.
The sample container shall be labelled.
The sampling location, date and time shall be recorded.
−1
When measuring very low levels of radon activity concentration (<10 Bq·l ), minimize any contact between
the sample and the atmosphere when taking the sample.
When measurement methods require specific precautions, these are listed in the relevant parts of ISO 13164
(e.g. when using degassing techniques, the temperature of the water shall be recorded).
7 Transportation and storage
The transportation and storage conditions shall be adapted to keep the integrity of the sample.
The container shall be protected and sealed to avoid opening during transportation. The container shall be
packed in an appropriate manner, especially around the cap, in order to prevent any leakage.
The sample shall be measured as soon as possible after sampling. When it is necessary to store the sample
for an extended period of time prior to measurement, it shall be stored at low temperature in a refrigerator
or similar storage facility in accordance with ISO 5667-1 and ISO 5667-3.
The duration of transportation and storage prior to analysis shall not exceed 48 hours, given be as short
as possible given the half-life of Rn, the expected activity concentration, and the detection limit of the
measurement method to be used.
NOTE the countdown for this 48-hour period starts at the moment of sample collection, not upon receipt at the
lab.
ISO/DIS 13164-1:2026(en)
Figure 2 — Diagram illustrating the techniques used to measure Rn in water

ISO/DIS 13164-1:2026(en)
Table 1 — Sampling conditions
Sampling type Container Sampling steps
— The container shall be made from a — Prepare the equipment.
material that is non-porous to radon
— Open the tap to obtain a continuous flow to
(e.g. aluminium). Use materials with a
avoid turbulence at the outlet of the tap and on
hydrophilic surface (e.g., glass, certain
the walls of the container.
treated plastics) to minimize gas
bubble formation and adhesion on the
— Take the sample carefully, allowing the stream
container walls Avoid the use of grease
of water to flow against the walls of the
and oil because of the high solubility of
container.
radon in those substances.
Sampling from an
— Fill the container completely in order to avoid
— The volume of the container shall be
outlet (tap, spring,
the presence of air in the container, but do
adapted to the test sample size needed
etc.)
not allow the container to overflow with
for the chosen measurement method
turbulence.
(refer to the relevant parts of this
International Standard).
— Close the container.
— The sealing of the container shall be
airtight (e.g. a cap with an aluminium
NOTE In some cases, it can be necessary to
liner).
purge the supply system before taking the sample
— The container shall be resistant to
shock and pressure
— Prepare the equipment.
— Ensure that the sampling point is
representative of the body of water concerned.
It is likely that stratification will make it
necessary to take several samples at different
— Type and size of container, see above.
Sampling by
lateral pos
...