prEN ISO 18562-4

Biocompatibility evaluation of breathing gas pathways in healthcare applications - Part 4: Tests for leachables in condensate (ISO/DIS 18562-4:2022)

ISO 18562-4:2017 specifies tests for substances leached by liquid water condensing into gas pathways of a medical device, its parts or accessories, which are intended to provide respiratory care or supply substances via the respiratory tract to a patient in all environments. The tests of this document are intended to quantify hazardous water-soluble substances that are leached from the medical device, its parts or accessories by condensate and then conveyed by that liquid to the patient. This document establishes acceptance criteria for these tests.
ISO 18562-4:2017 addresses potential contamination of the gas stream arising from the gas pathways, which is then conducted to the patient.
ISO 18562-4:2017 applies over the expected service life of the medical device in normal use and takes into account the effects of any intended processing or reprocessing
ISO 18562-4:2017 does not address biological evaluation of the surfaces of gas pathways that are in direct contact with the patient. The requirements for direct contact surfaces are found in the ISO 10993 series.
Medical devices, parts or accessories containing gas pathways that are addressed by this document include, but are not limited to, ventilators, anaesthesia workstations (including gas mixers), breathing systems, oxygen conserving devices, oxygen concentrators, nebulizers, low-pressure hose assemblies, humidifiers, heat and moisture exchangers, respiratory gas monitors, respiration monitors, masks, mouth pieces, resuscitators, breathing tubes, breathing systems filters, Y-pieces and any breathing accessories intended to be used with such devices. The enclosed chamber of an incubator, including the mattress, and the inner surface of an oxygen hood are considered to be gas pathways and are also addressed by this document.
ISO 18562-4:2017 does not address contamination already present in the gas supplied from the gas sources while medical devices are in normal use.
EXAMPLE Contamination arriving at the medical device from gas sources such as medical gas pipeline systems (including the non-return valves in the pipeline outlets), outlets of pressure regulators connected or integral to a medical gas cylinder, or room air taken into the medical device is not addressed by ISO 18562 series.
ISO 18562-4:2017 does not address contact with drugs or anaesthetic agents. If a medical device is intended to be used with anaesthetic agents or drugs, then additional testing can be required.
This document is intended to be read in conjunction with ISO 18562‑1.
NOTE This document has been prepared to address the relevant essential principles of safety and performance as indicated in Annex B.

Beurteilung der Biokompatibilität der Atemgaswege bei medizinischen Anwendungen - Teil 4: Prüfungen für herauslösbare Substanzen in Kondensaten (ISO/DIS 18562-4:2022)

Évaluation de la biocompatibilité des chemins de gaz respiratoires dans les applications de soins de santé - Partie 4: Essais concernant les substances relargables dans le condensat (ISO/DIS 18562-4:2022)

ISO 18562-4:2017 spécifie les essais concernant les substances relarguées dans l'eau qui se condense dans les chemins de gaz utilisés dans un dispositif médical, ses parties ou ses accessoires, qui sont destinés à dispenser des soins respiratoires ou à fournir des substances par les voies respiratoires à un patient dans tous les types d'environnements. Les essais du présent document sont destinés à quantifier les substances dangereuses hydrosolubles qui sont relarguées par le dispositif médical, ses parties ou ses accessoires dans le condensat, puis acheminées par le liquide jusqu'au patient. Le présent document établit les critères d'acceptation de ces essais.
ISO 18562-4:2017 traite de la contamination potentielle du flux gazeux provenant des chemins de gaz, qui est ensuite acheminé jusqu'au patient.
ISO 18562-4:2017 s'applique pour la durée de vie prévue du dispositif médical en utilisation normale et prend en compte les effets associés à tout traitement ou retraitement prévu.
ISO 18562-4:2017 ne traite pas de l'évaluation biologique des surfaces des chemins de gaz qui sont en contact direct avec le patient. Les exigences relatives aux surfaces en contact direct sont indiquées dans la série de normes ISO 10993.
Les dispositifs médicaux, leurs parties ou accessoires, contenant des chemins de gaz et faisant l'objet du présent document, comprennent, mais sans s'y limiter, les ventilateurs, les systèmes d'anesthésie (y compris les mélangeurs de gaz), les systèmes respiratoires, les économiseurs d'oxygène, les concentrateurs d'oxygène, les nébuliseurs, les flexibles de raccordement à basse pression, les humidificateurs, les échangeurs de chaleur et d'humidité, les moniteurs de gaz respiratoires, les moniteurs de respiration, les masques, les embouts buccaux, les appareils de réanimation, les tubes respiratoires, les filtres des systèmes respiratoires, les raccords en Y ainsi que tous les accessoires respiratoires destinés à être utilisés avec ces dispositifs médicaux. La chambre fermée d'un incubateur, y compris le matelas et la surface intérieure d'une cloche de Hood, sont considérés comme des chemins de gaz et sont également couverts par le présent document.
ISO 18562-4:2017 ne traite pas de la contamination déjà présente dans le gaz provenant des sources de gaz lors d'une utilisation normale des dispositifs médicaux.
EXEMPLE La contamination arrivant dans le dispositif médical et provenant de sources de gaz telles que des systèmes de distribution de gaz médicaux (notamment les clapets anti-retour situés sur les prises murales), les sorties des détendeurs raccordés ou intégrés à une bouteille de gaz médical, ou l'air ambiant envoyé dans le dispositif médical, ne sont pas couverts par la série de normes ISO 18562.
ISO 18562-4:2017 ne traite pas du contact avec les médicaments ou les agents anesthésiques. Si un dispositif médical est destiné à être utilisé avec des agents anesthésiques ou des médicaments, des essais supplémentaires peuvent être nécessaires.
ISO 18562-4:2017 est destiné à être lu conjointement à l'ISO 18562‑1.
NOTE Le présent document a été élaboré pour satisfaire aux principes essentiels de sécurité et de performances indiqués en Annexe B.

Ovrednotenje biokompatibilnosti vdihanega plina za uporabo v zdravstvu - 4. del: Preskusi izlužnin v kondenzatih (ISO/DIS 18562-4:2022)

General Information

• Status: Not Published
• Publication Date: 26-Nov-2024
• ICS: 11.040.10 - Anaesthetic, respiratory and reanimation equipment
• Technical Committee: CEN/TC 215 - Respiratory and anaesthetic equipment
• Drafting Committee: CEN/TC 215/WG 2 - Lung ventilators
• Current Stage: 4599 - Dispatch of FV draft to CMC - Finalization for Vote
• Start Date: 12-May-2023
• Completion Date: 12-May-2023
• Directive: 2017/745 - Regulation (EU) 2017/745 of the European Parliament and of the Council of 5 April 2017 on medical devices, amending Directive 2001/83/EC, Regulation (EC) No 178/2002 and Regulation (EC) No 1223/2009 and repealing Council Directives 90/385/EEC and 93/42/EEC
• Mandate: M/575 - Medical devices in support of Regulation (EU) 2017/745 and in vitro diagnostic medical devices in support of Regulation (EU) 2017/746
• Ref Project: oSIST prEN ISO 18562-4:2023 - Biocompatibility evaluation of breathing gas pathways in healthcare applications - Part 4: Tests for leachables in condensate (ISO/DIS 18562-4:2022)

Relations

• Revises: EN ISO 18562-4:2020 - Biocompatibility evaluation of breathing gas pathways in healthcare applications - Part 4: Tests for leachables in condensate (ISO 18562-4:2017)
• Effective Date: 18-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN ISO 18562-4:2023
01-januar-2023
Ovrednotenje biokompatibilnosti vdihanega plina za uporabo v zdravstvu - 4. del:
Preskusi izlužnin v kondenzatih (ISO/DIS 18562-4:2022)
Biocompatibility evaluation of breathing gas pathways in healthcare applications - Part 4:
Tests for leachables in condensate (ISO/DIS 18562-4:2022)
Beurteilung der Biokompatibilität der Atemgaswege bei medizinischen Anwendungen -
Teil 4: Prüfungen für herauslösbare Substanzen in Kondensaten (ISO/DIS 18562-4:2022)
Évaluation de la biocompatibilité des chemins de gaz respiratoires dans les applications
de soins de santé - Partie 4: Essais concernant les substances relargables dans le
condensat (ISO/DIS 18562-4:2022)
Ta slovenski standard je istoveten z: prEN ISO 18562-4
ICS:
11.040.10 Anestezijska, respiratorna in Anaesthetic, respiratory and
reanimacijska oprema reanimation equipment
oSIST prEN ISO 18562-4:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 18562-4:2023

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oSIST prEN ISO 18562-4:2023
DRAFT INTERNATIONAL STANDARD
ISO/DIS 18562-4
ISO/TC 121/SC 3 Secretariat: ANSI
Voting begins on: Voting terminates on:
2022-11-03 2023-01-26
Biocompatibility evaluation of breathing gas pathways in
healthcare applications —
Part 4:
Tests for leachables in condensate
Évaluation de la biocompatibilité des chemins de gaz respiratoires dans les applications de soins de
santé —
Partie 4: Essais concernant les substances relargables dans le condensat
ICS: 11.040.10
This document is circulated as received from the committee secretariat.
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
ISO/CEN PARALLEL PROCESSING
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
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POTENTIAL TO BECOME STANDARDS TO
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Reference number
NATIONAL REGULATIONS.
ISO/DIS 18562-4:2022(E)
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. © ISO 2022

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oSIST prEN ISO 18562-4:2023
ISO/DIS 18562-4:2022(E)
DRAFT INTERNATIONAL STANDARD
ISO/DIS 18562-4
ISO/TC 121/SC 3 Secretariat: ANSI
Voting begins on: Voting terminates on:

Biocompatibility evaluation of breathing gas pathways in
healthcare applications —
Part 4:
Tests for leachables in condensate
Évaluation de la biocompatibilité des chemins de gaz respiratoires dans les applications de soins de
santé —
Partie 4: Essais concernant les substances relargables dans le condensat
ICS: 11.040.10
This document is circulated as received from the committee secretariat.
COPYRIGHT PROTECTED DOCUMENT
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
© ISO 2022
ISO/CEN PARALLEL PROCESSING
THEREFORE SUBJECT TO CHANGE AND MAY
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
NOT BE REFERRED TO AS AN INTERNATIONAL
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on STANDARD UNTIL PUBLISHED AS SUCH.
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
IN ADDITION TO THEIR EVALUATION AS
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ISO copyright office
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CP 401 • Ch. de Blandonnet 8
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
CH-1214 Vernier, Geneva
POTENTIAL TO BECOME STANDARDS TO
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WHICH REFERENCE MAY BE MADE IN
Reference number
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NATIONAL REGULATIONS.
Website: www.iso.org ISO/DIS 18562-4:2022(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
Published in Switzerland
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
ii
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PROVIDE SUPPORTING DOCUMENTATION. © ISO 2022

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oSIST prEN ISO 18562-4:2023
ISO/DIS 18562-4:2022(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 General principles . 3
4.1 Type tests . 3
4.2 General . 3
5 Leachables in condensate . 3
5.1 Identifying applicable gas pathway surfaces . 3
5.2 Determining if testing is required . 3
5.3 Test methods . 4
5.3.1 General . 4
5.3.2 Sample collection . 5
5.3.3 Chemical characterization of leachables in condensate. 6
5.3.4 Calculation of tolerable exposure . 7
5.3.5 Calculation of exposure dose estimate . 7
5.3.6 Risk assessment . 7
5.3.7 Biological evaluation according to ISO 10993 standards . 8
6 Reporting . 9
Annex A (informative) Rationale and guidance .10
Annex B (informative) Reference to the IMDRF essential principles and labelling guidances .12
Annex C (informative) Reference to the essential principles .13
Annex ZA (informative) Relationship between this European standard and the General
Safety and Performance Requirements of Regulation (EU) 2017/745 aimed to be
covered .14
Bibliography .17
Terminology — Alphabetized index of defined terms .19
iii
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oSIST prEN ISO 18562-4:2023
ISO/DIS 18562-4:2022(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 Technical Committee ISO/TC 121, Anaesthetic and respiratory
equipment, Subcommittee SC 3, Respiratory devices and related equipment used for patient care in
collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC
215, Respiratory and anaesthetic equipment, in accordance with the Agreement on technical cooperation
between ISO and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 18562-4:2017), which has been
technically revised. The main changes compared to the previous edition are as follows:
— reformatted according to most recent Central Secretariat editing rules;
— added informative mapping annexes to relevant regulatory requirements;
— clarified terms and definitions used in the document;
— clarified the stepwise test procedure;
— required determination of volume of condensate that can reach the patient; and
— required calculating resulting exposure dose.
A list of all parts in the ISO 18562 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
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oSIST prEN ISO 18562-4:2023
ISO/DIS 18562-4:2022(E)
Introduction
This document is intended to protect patients connected to medical devices from harmful amounts of
substances that might be dissolved in water that has condensed in the gas pathways of those medical
devices. This document represents the application of the best-known science by addressing the risks
from potentially hazardous substances in the condensate being conveyed to the patient by the gas
pathway. The condensate itself will be distilled water, having condensed from the vapour phase. But
substances from within the medical device could leach into the liquid water (condensate) present in the
breathing system.
This document is intended to cover the biological evaluation of gas pathways of medical devices within
a risk management process, as part of the overall medical device evaluation and development. This
approach combines the review and evaluation of existing data from all sources with, where necessary,
the selection and application of additional tests.
In general, the ISO 10993 series is intended to cover the biological evaluation of medical devices.
However, the ISO 10993 series does not appropriately address the biological evaluation of the gas
pathways of medical devices.
It is not within the scope of this document to address contamination arising from the source of the
breathing gases entering such medical devices, but rather only address the potential contamination
generated from within the medical device itself. This contamination might be from the original
manufacturing process or generated by the medical device itself during use.
This document is concerned with substances that could be conveyed to the patient by liquid condensate
forming in the medical device and then subsequently reaching the lungs of the patient. Potentially
harmful substances that could be found in condensate include organic compounds and elements (such
as metals). Condensate management is part of most healthcare institution protocols, with the primary
aim of preventing the condensate reaching the patient in the first place. The absolute volume of liquid
reaching a patient by this route should therefore be low, but it might happen. This document outlines
tests for substances contained in the liquid.
The methods to determine the acceptable levels of contamination are contained in ISO 18562-1.
In this document, the following print types are used:
— requirements and definitions: roman type;
— informative material appearing outside of tables, such as notes, examples and references: in smaller
type. Normative text of tables is also in a smaller type;
— terms defined in Clause 3 of this document or as noted and test specifications: italic type;
This document has been prepared in consideration of:
— the Essential Principles of Safety and Performance of Medical Devices and IVD Medical Devices, IMDRF/
[17]
GRRP WG/N47:2018 as indicated in Annex B;
[18]
— the Labelling Principles for Medical Devices and IVD Medical Devices, IMDRF/GRRP WG/N52:2019
as indicated in Annex B;
[15]
— the essential principles of safety and performance of a medical device according to ISO 16142-1:2016
as indicated in Annex C; and
— the general safety and performance requirements of a medical device according to regulation
[19]
(EU) 2017/745 .
In this document, the conjunctive “or” is used as an “inclusive or” so a statement is true if any
combination of the conditions is true.
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oSIST prEN ISO 18562-4:2023
ISO/DIS 18562-4:2022(E)
For the purposes of this document, the auxiliary verb:
— “shall” indicates a requirement;
— “should” indicates a recommendation;
— “may” indicates a permission;
— "can" is used to describe a possibility or capability, and
— "must" indicates an external constraint.
Requirements in this document have been decomposed so that each requirement is uniquely delineated.
This is done to support automated requirements tracking.
vi
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oSIST prEN ISO 18562-4:2023
DRAFT INTERNATIONAL STANDARD ISO/DIS 18562-4:2022(E)
Biocompatibility evaluation of breathing gas pathways in
healthcare applications —
Part 4:
Tests for leachables in condensate
1 Scope
This document specifies tests for substances leached by liquid water condensing in gas pathways of
a medical device, its parts or accessories, which are intended to provide respiratory care or supply
substances via the respiratory tract to a patient in all environments. The chemical characterization
methods described in this document apply to chemical substances that could leach from the medical
device, its parts or accessories into the condensate. This document establishes verifiable acceptance
criteria for these tests. The identity and quantity of each chemical released is intended for toxicological
1)
risk assessment as described in ISO 18562-1:— .
This document addresses potential contamination of the gas stream arising from the gas pathways,
which is delivered to the patient.
This document applies over the expected lifetime of the medical device in normal use and takes into
account the effects of any intended processing.
This document does not address biological evaluation of the surfaces of gas pathways that have direct
contact with the patient. The requirements for direct contact surfaces are found in the ISO 10993 series.
Medical devices, parts or accessories containing gas pathways that are addressed by this document
include, but are not limited to, ventilators, anaesthesia workstations (including gas mixers), breathing
systems, oxygen conserving devices, oxygen concentrators, nebulizers, low-pressure hose assemblies,
humidifiers, heat and moisture exchangers, respiratory gas monitors, respiration monitors, masks,
mouth pieces, resuscitators, breathing tubes, breathing systems filters, Y-pieces and any breathing
accessories intended to be used with such devices. The enclosed chamber of an incubator, including
the mattress, and the inner surface of an oxygen hood are considered to be gas pathways and are also
addressed by this document.
This document does not address contamination already present in the gas supplied from the gas sources
while medical devices are in normal use.
EXAMPLE Contamination arriving at the medical device from gas sources such as medical gas pipeline
systems (including the non-return valves in the pipeline outlets), outlets of pressure regulators connected or
integral to a medical gas cylinder, or room air taken into the medical device.
This document does not address contact with drugs or anaesthetic agents. If a medical device or accessory
is intended to be used with anaesthetic agents or drugs, then additional testing can be required.
This document is intended to be read in conjunction with ISO 18562-1:—.
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.
1)  Under preparation. Stage at the time of publication: ISO/DIS 18562-1:2022.
1
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oSIST prEN ISO 18562-4:2023
ISO/DIS 18562-4:2022(E)
ISO 10993-1:2018, Biological evaluation of medical devices — Part 1: Evaluation and testing within a risk
management process
ISO 10993-5:2009, Biological evaluation of medical devices — Part 5: Tests for in vitro cytotoxicity
ISO 10993-10:2021, Biological evaluation of medical devices — Part 10: Tests for skin sensitization
ISO 10993-12:2021, Biological evaluation of medical devices — Part 12: Sample preparation and reference
materials
I S O 10 9 93-18:2020 +A M D1: 2022 , Biological evaluation of medical devices — Part 18: Chemical
characterization of materials
ISO 10993-23:2020, Biological evaluation of medical devices — Part 23: Tests for irritation
ISO 18562-1:—, Biocompatibility evaluation of breathing gas pathways in healthcare applications —
Part 1: Evaluation and testing within a risk management process
2)
ICH Q3D(R1):2016 , Guideline for elemental impurities
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 18562-1:— and the following
apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at https:// www .electropedia .org/
— ISO Online browsing platform: available at https:// www .iso .org/ obp
NOTE For convenience, an alphabetized index of all defined terms and their sources used in this document
are given at the end of the document.
3.1
exaggerated extraction
extraction that is intended to result in a greater amount of a chemical constituent being released as
compared to the amount generated under the simulated conditions of use
Note 1 to entry: It is important to ensure that the exaggerated extraction does not result in a chemical change of
the material.
[SOURCE: ISO 10993-12:2021, 3.3]
3.2
extractable
substance that is released from a medical device or material of construction when the medical device or
material is extracted using laboratory extraction conditions and vehicles
[SOURCE: ISO 10993-18:2020+AMD1: 2022, 3.16]
2)  Available at: (viewed 2021 03-12)
https:// admin .ich .org/ sites/ default/ files/ inline -files/ Q3D -R1EWG _Document _Step4 _Guideline _2019 _0322 .pdf
2
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oSIST prEN ISO 18562-4:2023
ISO/DIS 18562-4:2022(E)
4 General principles
4.1 Type tests
The tests described in this document are type tests. Type tests are performed on the final medical device,
a component of the medical device, portions of the final finished medical device or a representative
sample of the medical device, part or accessory being evaluated.
a) If representative samples are used, (i.e. manufactured and processed by equivalent methods),
consideration shall be made regarding whether or not the differences between the representative
sample and the final medical device or component could affect the results of the test.
b) Testing of representative samples (manufactured and processed by equivalent methods) instead of
the final medical device shall:
1) be supported by a description of any differences between the representative sample and the
final medical device; and
2) include a detailed rationale for why each difference is not expected to impact the biocompatibility
of the final medical device.
NOTE Some authorities having jurisdiction evaluate these differences and rationales.
4.2 General
All gas pathways from which the patient inspires gas shall be evaluated using the principles detailed in
ISO 18562-1:—.
5 Leachables in condensate
5.1 Identifying applicable gas pathway surfaces
a) A medical device, its parts or accessories shall not add leachables to the condensate at levels that
create an unacceptable risk to the patient.
b) All gas pathways from which the patient inspires gas in normal use and normal condition shall be
evaluated for leachables in condensate, where
— gas in the gas pathway can reach 100 % saturation with water at some point in the gas pathway,
— condensate can form on the gas pathway surfaces, and
— liquid condensate can reach the patient.
NOTE 1 Condensate, which in itself is water, can form in gas pathways and can take the form
of liquid drops or a film of water on the gas pathway walls. This liquid water can extract substances
from the materials of the walls that would not be extracted by the breathing gas alone. If this liquid
condensate can reach the patient, it could potentially convey harmful substances to the patient.
1) Reasonably foreseeable use errors that can affect condensate reaching the patient should also be
considered one use error at a time.
NOTE 2 Reasonably foreseeable use errors can include incorrect equipment set up.
5.2 Determining if testing is required
a) The evaluation should use the risk management process to assess if testing is required.
b) Sections of the gas pathway from which the patient cannot be exposed to condensate need not be
tested.
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oSIST prEN ISO 18562-4:2023
ISO/DIS 18562-4:2022(E)
EXAMPLE 1 An exhaust gas pathway separated by a check valve preventing backflow of condensate to
the patient.
1) The rationale for excluding gas pathways where the patient cannot be exposed to condensate
shall be documented in the report.
c) If the medical device part or accessory is identical or sufficiently similar in formulation, geometry,
manufacturing processes or application processes, packaging and any subsequent processing to an
existing medical device with the same intended use and worst case clinically relevant conditions, an
evaluation may conclude that no further testing is required. Refer to ISO 18562-1:—, Figure 2 and
ISO 10993-18:2020+AMD1: 2022, C.2.
NOTE 1 Manufacturing and application processes include processing (i.e., cleaning/disinfection/
sterilization either prior to use or between uses).
1) Any differences between the medical device part or accessory and existing medical device part
or accessory
i) shall be documented in the report, with
ii) a rationale provided in the report for why the changes do not negatively impact the
condensate volume and leachable profile.
d) If the medical device under evaluation has already been evaluated as an external communicating
medical device with contact to tissue/bone/dentin in accordance with ISO 10993-1:2018, then the
tests in 5.3 need not be performed.
EXAMPLE 2 A tracheal tube, because of its direct contact with the patient, is evaluated utilizing
ISO 10993-1. In this case, the tests of this document are not required.
NOTE 2 Some authorities having jurisdiction might require the tests of 5.3 if the medical device is intended
for use on particularly vulnerable patient populations, such as neonates.
e) If the risk management process determines that testing is required, the tests of 5.3 shall be
performed.
5.3 Test methods
5.3.1 General
The condensate evaluation of gas pathways shall include
a) establishing the worst-case clinically relevant maximum volume of condensates that can be
conveyed to the patient.
NOTE 1 There is guidance and rationale for this list item contained in Clause A.2.
1) This shall be done by one of the following:
i) experimentally determining in normal use and normal condition under worst-case clinically
relevant parameters (e.g., temperature, gas flowrate, etc.) the volume of condensate
reaching the patient; or
I) Normal use shall include reasonably foreseeable use errors that contribute to
condensate reaching the patient, one use error at a time (e.g., selection of incorrect
settings for a patient or incorrect equipment set up).
NOTE 2 Normal use assumes the implementation of specific measures described in the
instructions for use intended to avoid or reduce patient exposure to condensate. The worst-case amount
of condensate that can be formed and reach the patient from simultaneous use errors is not relevant. A
lower volume can then be justified for the toxicological risk assessment.
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oSIST prEN ISO 18562-4:2023
ISO/DIS 18562-4:2022(E)
II) All reasonably foreseeable use errors shall be documented in the report with the
respective condensate volumes generated.
III) If the experimentally determined volume of condensate reaching the patient establishes
that no condensate reaches the patient under worst case clinical conditions, then no
further testing is required.
IV) The experimental methods shall be justified in the report.
NOTE 3 Breathing gas pathways are systems that commonly include multiple medical devices
and accessories, often from different manufacturers. The subject medical device or accessory needs to be
evaluated in its intended use as part of a system and might not be the part that determines the volume of
condensate forming and being delivered to the patient.
ii) by justified arguments in the report.
NOTE 4 Some authorities having jurisdiction can require experimental testing.
b) the chemical characterization of the leachables in the condensate.
c) performing a toxicological risk assessment on the leachables in condensate with respect to systemic
effects.
d) condensate testing of the leachables with respect to the following local e
...