prEN ISO 9360-2

• Status: Not Published
• Publication Date: 12-Mar-2028
• ICS: 11.040.10 - Anaesthetic, respiratory and reanimation equipment
• Technical Committee: CEN/TC 215 - Respiratory and anaesthetic equipment
• Drafting Committee: CEN/TC 215 - Respiratory and anaesthetic equipment
• Current Stage: 4020 - Submission to enquiry - Enquiry
• Start Date: 20-Aug-2026
• Completion Date: 20-Aug-2026
• Ref Project: oSIST prEN ISO 9360-2:2026 - Heat and moisture exchangers, and breathing system filters for respired gases - Part 2: Measurement of moisture loss (ISO/DIS 9360-2:2026)

• Referred By: EN ISO 12855:2022 - Electronic fee collection - Information exchange between service provision and toll charging (ISO 12855:2022)
• Effective Date: 28-Jan-2026
• Referred By: EN ISO 12855:2025 - Electronic fee collection - Information exchange between service provision and toll charging (ISO 12855:2025)
• Effective Date: 28-Jan-2026
• Revises: EN ISO 9360-2:2009 - Anaesthetic and respiratory equipment - Heat and moisture exchangers (HMEs) for humidifying respired gases in humans - Part 2: HMEs for use with tracheostomized patients having minimum tidal volumes of 250 ml (ISO 9360-2:2001)
• Effective Date: 19-Feb-2025

Overview

prEN ISO 9360-2:2026 is an international draft standard developed by CEN and ISO/TC 121/SC 2. It focuses on the measurement of moisture loss from heat and moisture exchangers (HMEs), heat and moisture exchanging filters (HMEFs), and breathing system filters (BSFs) used in medical respiration systems. These devices serve a critical role in maintaining the humidity and temperature of gases inhaled by patients during anaesthesia, ventilation, or spontaneous breathing with tracheostomy.

Medical gases typically lack sufficient moisture for safe and comfortable respiratory function. HMEs and filters address this deficiency, making the measurement and standardization of their moisture-retentive performance essential for patient safety and consistent device quality.

Key Topics

• Scope of the Standard

  • Specifies methods to measure moisture loss from HMEs, HMEFs, and some BSFs.
  • Applicable to adult breathing systems with tidal volumes of 250 mL or more.
  • Includes devices used with tracheostomy patients not requiring mechanical ventilation.
  • Excludes active HMEs, which are covered by a separate standard (ISO 80601-2-74).

• Test Apparatus and Procedures

  • Outlines requirements for the test apparatus, including a humidity generator, reservoir, insulated chamber, and weighing equipment.
  • Describes specific test conditions (air temperature, humidity, tidal volume, respiratory rate, and inspiratory-to-expiratory ratio).
  • Includes a standardized method for calculating moisture loss over time.

• Comparative Evaluation

  • Provides guidelines for using calibration reference HMEs to ensure repeatability and comparability between devices.
  • States that test results are mainly comparative rather than exact physiological simulations.

• Terminology and Reference Framework

  • Relies on definitions from ISO 9360-1 and ISO/IEC terminology databases.
  • References other applicable standards for connectors and alternative testing (e.g., ISO 5356-1, ISO TS 24172).

Applications

prEN ISO 9360-2:2026 is highly relevant across healthcare settings and the medical device industry, particularly for:

• Medical Device Manufacturers

  • Ensures that HMEs and filters consistently meet moisture retention requirements.
  • Supports product validation, design optimization, and regulatory compliance.

• Testing Laboratories

  • Provides standardized procedures for third-party product certification and type testing.
  • Enables comparative product assessments for procurement and quality control.

• Healthcare Facilities

  • Helps clinicians and biomedical engineers select devices with proven moisture retention performance, crucial for patient comfort and airway safety.

• Regulatory Bodies

  • May serve as a reference for national and international regulations relating to breathing system humidification standards.

By adhering to prEN ISO 9360-2, stakeholders contribute to improved patient outcomes, minimized airway complications, and enhanced consistency in respiratory care.

Related Standards

For effective implementation and integration, prEN ISO 9360-2 should be considered alongside the following standards:

• ISO 9360-1: Heat and moisture exchangers, and breathing system filters for respired gases - Part 1: Common requirements
• ISO 80601-2-74:2026: Medical electrical equipment - Particular requirements for basic safety and essential performance of respiratory humidifying equipment (covers active HMEs)
• ISO 5356-1:2015: Anaesthetic and respiratory equipment - Conical connectors
• ISO TS 24172: Alternative test method for heat and moisture exchangers

These references ensure comprehensive coverage of device safety, performance, and compatibility within anaesthetic and respiratory equipment standards.

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Keywords: heat and moisture exchanger standard, prEN ISO 9360-2, breathing system filter testing, measurement of moisture loss, medical device humidification, respiratory care standards, HME performance, CEN ISO standards, clinical respiratory equipment, moisture retention in ventilator filters

SLOVENSKI STANDARD
01-oktober-2026
Izmenjevalniki toplote in vlage ter filtri dihalnih sistemov za dihalne pline - 2. del:
Merjenje izgube vlage (ISO/DIS 9360-2:2026)
Heat and moisture exchangers, and breathing system filters for respired gases - Part 2:
Measurement of moisture loss (ISO/DIS 9360-2:2026)
Anästhesie- und Beatmungsgeräte - Wärme- und Feuchtigkeitsaustauscher und
Atemschutzfilter (HMEF) zur Anfeuchtung von Atemgasen beim Menschen - Teil 2:
Messung von Feuchtigkeitsverlusten (ISO/DIS 9360-2:2026)
Titre manque — Partie 2: Titre manque
Ta slovenski standard je istoveten z: prEN ISO 9360-2
ICS:
11.040.10 Anestezijska, respiratorna in Anaesthetic, respiratory and
reanimacijska oprema reanimation equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 9360-2
ISO/TC 121/SC 2
Heat and moisture exchangers, and
Secretariat: ANSI
breathing system filters for respired
Voting begins on:
gases —
2026-08-20
Part 2:
Voting terminates on:
2026-11-12
Measurement of moisture loss
ICS: 11.040.10
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 has not been edited by the ISO Central 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 9360-2:2026(en)
DRAFT
ISO/DIS 9360-2:2026(en)
International
Standard
ISO/DIS 9360-2
ISO/TC 121/SC 2
Heat and moisture exchangers, and
Secretariat: ANSI
breathing system filters for respired
Voting begins on:
gases —
2026-08-20
Part 2:
Voting terminates on:
2026-11-12
Measurement of moisture loss
ICS: 11.040.10
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 has not been edited by the ISO Central 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
WHICH REFERENCE MAY BE MADE IN
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 9360-2:2026(en)
ii
ISO/DIS 9360-2:2026(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Measurement of moisture loss . 2
4.1 Principle .2
4.2 Test apparatus.2
4.3 Test conditions .8
4.4 Procedure .8
5 Measurement of moisture loss from HME/HMEFs without a machine port .10
5.1 Principle .10
5.2 Test apparatus.10
5.3 Test conditions .10
5.4 Procedure .10
Annex A (informative) Lists of parts and specifications in Figure 1 and Figure 2.13
Annex B (informative) Rationale .15
Bibliography . 17

iii
ISO/DIS 9360-2:2026(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.
International Standard ISO 9360-2 was prepared by Technical Committee ISO/TC 121, Anaesthetic and
respiratory equipment, Subcommittee SC 2, Airway devices and related equipment.
ISO 9360 consists of the following parts, under the general title Breathing system filters for anaesthetic and
respiratory use:
— Part 1: Common requirements
— Part 2: Measurement of moisture loss
— Part 3: Measurement of filtration performance
These parts technically revise and replace ISO 9360-1:2000, ISO 9360-2:2001, ISO 23328-1:2008 and
ISO 23328-2:2009.
These parts are a combination of the above standards with new and modified requirements, in particular:
— Part 1 combines requirements from ISO 9360-1:2000 and ISO 23328-2:2009
— Part 2 combines requirements from ISO 9360-1:2000 and ISO 9360-2:2001
— Part 3 are requirements from ISO 23328-1:2008
Changes from the previous standards are:
— Corrected dimensions for the calibration HME and heated water bath side view

iv
ISO/DIS 9360-2:2026(en)
Introduction
The gases generally available for medical use lack sufficient moisture to be physiologically acceptable to
the respiratory tract of patients. Heat and moisture exchangers (HME) are used to raise the water content
and the temperature of the gas delivered to the respiratory tract of spontaneously and non spontaneously
breathing patients. HMEs are intended to form part of a ventilator breathing system. HME's are primarily
placed between the patient interface (e.g. Tracheal or Tracheostomy tube) and the anaesthesia or ventilator
breathing set. HME's are also intended for use with tracheostomy tubes where the HME is not designed to
connect to an anaesthesia or ventilator breathing set.

v
DRAFT International Standard ISO/DIS 9360-2:2026(en)
Heat and moisture exchangers, and breathing system filters
for respired gases —
Part 2:
Measurement of moisture loss
1 Scope
This document specifies requirements for the measurement of moisture loss from heat and moisture
exchangers (HMEs), including those incorporating breathing system filters (HMEFs), intended for the
humidification of respired gases for use primarily with patients with a tidal volume equal to or greater than
250 ml.
Breathing system filters (BSF) are also included in scope, as these devices do some amount of moisture to
inspired gases.
This document also includes requirements for the measurement of moisture loss from HMEs for use with
tracheostomized patients that do not have a machine port and having minimum tidal volumes of 250 mL.
Active HMEs are excluded from this document, the requirements for active HMEs are included in
[1]
ISO 80601-2-74:2026 .
NOTE 1 Wherever the term “device” is used in this document, it may either refer to HME, HMEF or BSF.
*** Add rationale why 250ml lower limit***
NOTE 2 HMEs, HMEFs that do not have a machine port for connection to a breathing tube are intended for patients
who are spontaneously breathing via a tracheostomy and do not require mechanical ventilation.
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 5356-1:2015, Anaesthetic and respiratory equipment — Conical connectors — Part 1: Cones and sockets
ISO 9360-1: 202X Heat and moisture exchangers, and breathing system filters for respired gases — Part 1:
Common requirements
ISO TS 24172, Alternative test method for heat and moisture exchangers
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 9360-1: 202X 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/

ISO/DIS 9360-2:2026(en)
NOTE The terms given in Clause 3 are delineated throughout the text in italics.
4 Measurement of moisture loss
NOTE There is guidance or rationale for this subclause contained in Annex B.
4.1 Principle
The performance of the device shall be measured by recording the mass of water lost from the test apparatus
specified in 4.2.
NOTE An alternative method to determine heat and moisture exchanging efficiency can be found in ISO TS 24172.
4.2 Test apparatus
NOTE There is guidance or rationale for this subclause contained in Annex B.
The test apparatus (Figure 1) shall comprise the following components.
a) A bidirectional flow generator, which is a mechanically driven piston used to produce a flow having a
sinusoidal waveform.
b) A Humidity generator (HG), consisting of
1) a heated water bath (Figure 2) through which air is bubbled in both directions;
2) a rigid cylindrical reservoir (Figure 3) with a maximum volume of 7 L and a diameter of
approximately 150 mm, containing a 2 L reservoir bag;
3) a thermally insulated chamber (Figure 4), which contains the water bath, the reservoir and a heat
source.
c) An air delivery system (Figure 5), consisting of a T-piece with an internal diameter greater than 15 mm,
and an exhaust tube at least 200 mm in length.
d) Weighing equipment, with an accuracy of ± 0,1 g or better in the range of the mass to be measured.
e) Flowrate measuring equipment, with an accuracy of at least 5 % of the reading.
f) Calibration HME (Figure 6) consisting of a housing containing 81 polyvinyl chloride (PVC) tubes
arranged in a 9 × 9 array, each with an internal diameter of 2 mm, an external diameter of 4 mm, and a
length of 50 mm.
When the apparatus has been constructed and operated as specified in 4.4 the moisture loss from the
humidity generator with the calibration HME will be as shown in Table 2.

ISO/DIS 9360-2:2026(en)
Dimensions in millimetres
Key
1 to 19 see Annex A
20 sine wave generator inlet
21 air outlet
22 dry air supply 23 ± 1 °C, < 1 mg H O per litre air
23 weighing equipment
Figure 1 — Test apparatus side view

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