SIST EN ISO 80601-2-74:2021

SLOVENSKI STANDARD
01-oktober-2021
Nadomešča:
SIST EN ISO 80601-2-74:2020
Medicinska električna oprema - 2-74. del: Posebne zahteve za osnovno varnost in
bistvene lastnosti za vlažilne sisteme dihalne opreme (ISO 80601-2-74:2021)
Medical electrical equipment - Part 2-74: Particular requirements for basic safety and
essential performance of respiratory humidifying equipment (ISO 80601-2-74:2021)
Medizinische elektrische Geräte - Teil 2-74: Besondere Festlegungen für die Sicherheit
einschließlich der wesentlichen Leistungsmerkmale von Anfeuchtersystemen für
Atemgase (ISO 80601-2-74:2021)
Appareils électromédicaux - Partie 2-74: Exigences particulières pour la sécurité de base
et les performances essentielles des équipements d'humidification respiratoire (ISO
80601-2-74:2021)
Ta slovenski standard je istoveten z: EN ISO 80601-2-74:2021
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.

EN ISO 80601-2-74
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2021
EUROPÄISCHE NORM
ICS 11.040.10 Supersedes EN ISO 80601-2-74:2020
English Version
Medical electrical equipment - Part 2-74: Particular
requirements for basic safety and essential performance of
respiratory humidifying equipment (ISO 80601-2-
74:2021)
Appareils électromédicaux - Partie 2-74: Exigences Medizinische elektrische Geräte - Teil 2-74: Besondere
particulières pour la sécurité de base et les Festlegungen für die Sicherheit einschließlich der
performances essentielles des équipements wesentlichen Leistungsmerkmale von
d'humidification respiratoire (ISO 80601-2-74:2021) Anfeuchtersystemen für Atemgase (ISO 80601-2-
74:2021)
This European Standard was approved by CEN on 2 July 2021.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 80601-2-74:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 80601-2-74:2021) has been prepared by Technical Committee ISO/TC 121
"Anaesthetic and respiratory equipment" in collaboration with Technical Committee CEN/TC 215
“Respiratory and anaesthetic equipment” the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by January 2022, and conflicting national standards shall
be withdrawn at the latest by January 2022.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 80601-2-74:2020.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN websites.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 80601-2-74:2021 has been approved by CEN as EN ISO 80601-2-74:2021 without any
modification.
INTERNATIONAL ISO
STANDARD 80601-2-74
Second edition
2021-07
Medical electrical equipment —
Part 2-74:
Particular requirements for basic
safety and essential performance of
respiratory humidifying equipment
Appareils électromédicaux —
Partie 2-74: Exigences particulières pour la sécurité de base et
les performances essentielles des équipements d'humidification
respiratoire
Reference number
ISO 80601-2-74:2021(E)
©
ISO 2021
ISO 80601-2-74:2021(E)
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
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Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

ISO 80601-2-74:2021(E)
Contents Page
Foreword . v
Introduction . vii
201.1 Scope, object and related standards. 1
201.2 Normative references . 3
201.3 Terms and definitions . 5
201.4 General requirements . 8
201.5 General requirements for testing of ME equipment . 11
201.6 Classification of ME equipment and ME systems . 12
201.7 ME equipment identification, marking and documents . 13
201.8 Protection against electrical hazards form ME equipment . 20
201.9 Protection against mechanical hazards of ME equipment and ME systems. 20
201.10 Protection against unwanted and excessive radiation hazards . 21
201.11 Protection against excessive temperatures and other hazards . 21
201.12 Accuracy of controls and instruments and protection against hazardous outputs
.......................................................................................................................................................... 24
201.13 Hazardous situations and fault conditions for ME Equipment . 30
201.14 Programmable electrical medical systems (PEMS) . 31
201.15 Construction of ME equipment . 32
201.16 ME systems . 32
201.16.2 Accompanying documents of an ME system . 32
201.17 Electromagnetic compatibility of ME equipment and ME systems . 32
201.101 Breathing system connectors and ports . 33
201.102 Requirements for the breathing system and accessories . 35
201.103 Liquid container . 36
201.104 Functional connection . 36
202 Electromagnetic disturbances — Requirements and tests . 37
206 Usability . 38
208 General requirements, tests and guidance for alarm systems in medical
electrical equipment and medical electrical systems . 39
211 Requirements for medical electrical equipment and medical electrical systems
used in the home healthcare environment . 39
Annex C (informative)  Guide to marking and labelling requirements for ME equipment
and ME systems . 40
Annex D (informative)  Symbols on marking . 45
Annex AA (informative)  Particular guidance and rationale . 47
Annex BB (normative)  * Determination of the accuracy of the displayed measured gas
temperature . 64
Annex CC (normative)  * Determination of the humidification output . 66
Annex DD (normative)  * Specific enthalpy calculations . 71
Annex EE (normative)  Removable temperature sensors and mating ports . 73
Annex FF (normative)  * Reference temperature sensor . 77
ISO 80601-2-74:2021(E)
Annex GG (informative)  Saturation vapour pressure . 80
Annex HH (informative)  Reference to the IMDRF essential principles and labelling
guidances . 81
Annex II (informative)  Reference to the essential principles of safety and performance of
medical devices in accordance with ISO 16142-1:2016 . 85
Annex JJ (informative)  Reference to the general safety and performance requirements
.......................................................................................................................................................... 88
Annex KK (informative)  Terminology — Alphabetized index of defined terms . 91
Bibliography . 95

iv
ISO 80601-2-74:2021(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 jointly by Technical Committee ISO/TC 121, Anaesthetic and respiratory
equipment, Subcommittee SC 3, Respiratory devices and related equipment used for patient care, and
Technical Committee IEC/TC 62, Electrical equipment in medical practice, Subcommittee SC 62D,
Electromedical equipment, 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 80601-2-74:2017), which has been
technically revised.
The main changes compared to the previous edition are as follows:
— harmonization with the ‘A2 project’ of the general standard;
— harmonization with ISO 20417;
— addition of category 3 for respiratory high-flow therapy equipment;
— modification of requirements for humidification output of category 2 humidifiers;
— addition of requirements for maximum temperature in normal use;
— addition of requirements for static and dynamic temperature stability;
ISO 80601-2-74:2021(E)
— addition of requirements for low humidification output alarm condition;
— modification of audible acoustic energy test procedure;
— modification of thermal requirements for applied parts;
— modification of measured gas temperature test procedure;
— enlarged the ØW dimension of the temperature sensor port; and
— modification of humidification output test procedure.
A list of all parts in the ISO 80601 series and the IEC 80601 series can be found on the ISO and IEC
websites.
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.
vi
ISO 80601-2-74:2021(E)
Introduction
This document specifies requirements for respiratory humidifying equipment intended for use on
patients in home healthcare environment and in healthcare facilities. Humidifiers are used to raise the
water content of gases delivered to patients. Gases available for medical use do not contain sufficient
moisture and can damage or irritate the respiratory tract or desiccate secretions of patients whose
upper airways have been bypassed. Inadequate humidity in the inspired gas can cause drying of the
upper airway, or desiccation of tracheo-bronchial secretions in the tracheal or tracheostomy tube,
[25] [38]
which can cause narrowing or even obstruction of the airway . Heat is employed to increase the
water output of the humidifier.
In addition, many humidifiers utilize heated breathing tubes in order to increase operating efficiency and
reduce water loss (condensate) as well as heat loss in the breathing tube. Ventilator and anaesthesia
breathing tubes in common use might not withstand the heat generated by humidifiers and breathing
tube heating mechanisms.
Many humidifier manufacturers use off-the-shelf electrical connectors for their electrically heated
breathing tubes. However, since different manufacturers have used the same electrical connector for
different power outputs, electrically heated breathing tubes can be physically, but not electrically,
interchangeable. Use of improper electrically heated breathing tubes has caused overheating, circuit
melting, patient and operator burns and fires. It was not found practical to specify the interface
requirements for electrical connectors to ensure compatibility between humidifiers and breathing tubes
produced by different manufacturers.
Since the safe use of a humidifier depends on the interaction of the humidifier with its many accessories,
this document sets total system performance requirements up to the patient-connection port. These
requirements are applicable to accessories such as breathing tubes (both heated and non-heated),
temperature sensors and equipment intended to control the environment within these breathing tubes.
Humidification can also be used by respiratory support ME equipment to increase patient comfort and
compliance with the therapy. Examples are obstructive sleep apnoea and nasal high-flow therapy
equipment. The humidification output requirements of such ME equipment is less demanding as the
patient’s upper airway is not bypassed.
Humidifiers are commonly used with air and air-oxygen mixtures and any humidifier should be able to
operate with these gases. Care should be taken if using other gas mixes such as helium-oxygen mixtures,
as the different physical and thermal properties of these gases may disturb the operation of the
humidifier.
In this document, the following print types are used:
— Requirements and definitions: roman type;
— Test specifications and terms defined in Clause 3 of the general standard, in this document or as noted:
italic 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;
In referring to the structure of this document, the term
— “clause” means one of the five numbered divisions within the table of contents, inclusive of all
subdivisions (e.g. Clause 201 includes subclauses 201.7, 201.8, etc.);
— “subclause” means a numbered subdivision of a clause (e.g. 201.7, 201.8 and 201.9 are all
subclauses of Clause 201).
ISO 80601-2-74:2021(E)
References to clauses within this document are preceded by the term “Clause” followed by the clause
number. References to subclauses within this document are by number only.
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.
For the purposes of this document, the auxiliary verb:
— “shall” means that conformance with a requirement or a test is mandatory for conformance with
this document;
— “should” means that conformance with a requirement or a test is recommended but is not
mandatory for conformance with this document;
— “may” is used to describe permission (e.g. a permissible way to achieve conformance with a
requirement or test);
— "can" is used to describe a possibility or capability; and;
— "must" is used to express an external constraint.
Annex C contains a guide to the marking and labelling requirements in this document.
Annex D contains a summary of the symbols referenced in this document.
An asterisk (*) as the first character of a title or at the beginning of a paragraph or table title indicates
that there is guidance or rationale related to that item in Annex AA.
viii
INTERNATIONAL STANDARD ISO 80601-2-74:2021(E)

Medical electrical equipment —
Part 2-74:
Particular requirements for basic safety and essential
performance of respiratory humidifying equipment
201.1 Scope, object and related standards
Clause 1 of IEC 60601-1:2005+AMD1:2012+AMD2:2020 applies, except as follows.
NOTE The general standard is IEC 60601-1:2005+AMD1:2012+AMD2:2020.
201.1.1 * Scope
Replacement:
This document applies to the basic safety and essential performance of a humidifier, also hereafter
referred to as ME equipment, in combination with its accessories, the combination also hereafter
referred to as ME system.
This document is also applicable to those accessories intended by their manufacturer to be connected to
a humidifier where the characteristics of those accessories can affect the basic safety or essential
performance of the humidifier.
EXAMPLE 1 Heated breathing tubes (heated-wire breathing tubes) or ME equipment intended to control these
heated breathing tubes (heated breathing tube controllers).
NOTE 1 Heated breathing tubes and their controllers are ME equipment and are subject to the requirements of
IEC 60601-1.
NOTE 2 ISO 5367 specifies other safety and performance requirements for breathing tubes.
This document includes requirements for the different medical uses of humidification, such as invasive
ventilation, non-invasive ventilation, nasal high-flow therapy, and obstructive sleep apnoea therapy, as
well as humidification therapy for tracheostomy patients.
NOTE 3 A humidifier can be integrated into other equipment. When this is the case, the requirements of the
other equipment also apply to the humidifier.
[10]
EXAMPLE 2 Heated humidifier incorporated into a critical care ventilator where ISO 80601-2-12 also
applies.
EXAMPLE 3 Heated humidifier incorporated into a homecare ventilator for dependent patients where
[12]
ISO 80601-2-72 also applies.
[11]
EXAMPLE 4 Heated humidifier incorporated into sleep apnoea therapy equipment where ISO 80601-2-70
also applies.
EXAMPLE 5 Heated humidifier incorporated into ventilatory support equipment where either ISO 80601-2-
[13] [14]
79 or ISO 80601-2-80 also apply.
EXAMPLE 6 Heated humidifier incorporated into respiratory high-flow therapy equipment where
[15]
ISO 80601-2-90 also applies.
ISO 80601-2-74:2021(E)
This document also includes requirements for an active HME (heat and moisture exchanger),
ME equipment which actively adds heat and moisture to increase the humidity level of the gas delivered
from the HME to the patient. This document is not applicable to a passive HME, which returns a portion
of the expired moisture and heat of the patient to the respiratory tract during inspiration without
adding heat or moisture.
[4]
NOTE 4 ISO 9360-1 and ISO 9360-2 specify safety and performance requirements for a passive HME.
NOTE 5 If a clause or subclause is specifically intended to be applicable to ME equipment only, or to ME systems
only, the title and content of that clause or subclause will say so. If that is not the case, the clause or subclause
applies both to ME equipment and to ME systems, as relevant.
Hazards inherent in the intended physiological function of ME equipment or ME systems within the
scope of this document are not covered by specific requirements in this document except in
IEC 60601-1:2005+AMD1:2012+AMD2:2020, 7.2.13 and 8.4.1.
NOTE 6 Additional information can be found in IEC 60601-1:2005+AMD1:2012+AMD2:2020, 4.2.
This document does not specify the requirements for cold pass-over or cold bubble-through
[6]
humidification devices, the requirements for which are given in ISO 20789 .
This document is not applicable to equipment commonly referred to as “room humidifiers” or
humidifiers used in heating, ventilation and air conditioning systems, or humidifiers incorporated into
infant incubators.
This document is not applicable to nebulizers used for the delivery of a drug to patients.
[7]
NOTE 7 ISO 27427 specifies the safety and performance requirements for nebulizers.
201.1.2 Object
Replacement:
The object of this document is to establish particular basic safety and essential performance
requirements for a humidifier, as defined in 201.3.214, and its accessories.
Accessories are included because the combination of the humidifier and the accessories needs to be
adequately safe. Accessories can have a significant impact on the basic safety or essential performance of
a humidifier.
NOTE 1 This document has been prepared to address the relevant essential principles and labelling guidances
of the International Medical Devices Regulators Forum (IMDRF) as indicated in Annex HH.
NOTE 2 This document has been prepared to address the relevant essential principles of safety and performance
of ISO 16142-1:2016 as indicated in Annex II.
NOTE 3 This document has been prepared to address the relevant general safety and performance
requirements of European regulation (EU) 2017/745 as indicated in Annex JJ.
201.1.3 Collateral standards
Addition (add after existing text):
This document refers to those applicable collateral standards that are listed in Clause 2 of the general
standard and in 201.2 of this document.
IEC 60601-1-2:2014+AMD1:2020, IEC 60601-1-6:2010+AMD1:2013+AMD2:2020,
IEC 60601-1-8:2006+AMD1:2012+AMD2:2020 and IEC 60601-1-11:2015+AMD1:2020 apply as
modified in Clauses 202, 206, 208 and 211, respectively. IEC 60601-1-3:2008+AMD1:2013 does not
apply. All other published collateral standards in the IEC 60601-1 series apply as published.
2 © ISO 2021 – All rights reserved

ISO 80601-2-74:2021(E)
201.1.4 Particular standards
Replacement:
In the IEC 60601 series, particular standards define basic safety and essential performance
requirements, and may modify, replace or delete requirements contained in the general standard and
collateral standards as appropriate for the particular ME equipment under consideration.
A requirement of a particular standard takes priority over the general standard.
For brevity, IEC 60601-1:2005+AMD1:2012+AMD2:2020 is referred to in this document as the general
standard. Collateral standards are referred to by their document number.
The numbering of clauses and subclauses of this document corresponds to that of the general standard
with the prefix “201” (e.g. 201.1 in this document addresses the content of Clause 1 of the general
standard) or applicable collateral standard with the prefix “20x”, where x is the final digit(s) of the
collateral standard document number (e.g. 202.4 in this document addresses the content of Clause 4 of
the IEC 60601-1-2 collateral standard, 208.6 in this document addresses the content of Clause 6 of the
IEC 60601-1-8 collateral standard, etc.). The changes to the text of the general standard are specified by
the use of the following words:
“Replacement” means that the clause or subclause of the general standard or applicable collateral
standard is replaced completely by the text of this document.
“Addition” means that the text of this document is additional to the requirements of the general
standard or applicable collateral standard.
“Amendment” means that the clause or subclause of the general standard or applicable collateral
standard is amended as indicated by the text of this document.
Clauses, subclauses, figures or tables which are additional to those of the general standard are
numbered starting from 201.101. However, due to the fact that definitions in the general standard are
numbered 3.1 through 3.154, additional definitions in this document are numbered beginning from
201.3.201. Additional annexes are lettered AA, BB, etc., and additional items aa), bb), etc.
Subclauses, figures or tables which are additional to those of a collateral standard are numbered
starting from 20x, where “x” is the number of the collateral standard, e.g. 202 for IEC 60601-1-2, 211 for
IEC 60601-1-11, etc.
The term “this document” is used to make reference to the general standard, any applicable collateral
standards and this particular document taken together.
Where there is no corresponding clause or subclause in this document, the clause or subclause of the
general standard or applicable collateral standard, although possibly not relevant, applies without
modification; where it is intended that any part of the general standard or applicable collateral
standard, although possibly relevant, is not to be applied, a statement to that effect is given in this
document.
201.2 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.
Clause 2 of IEC 60601-1:2005+AMD1:2012+AMD2:2020 applies, except as follows.
Replacement:
Addition:
ISO 3744:2010, Acoustics — Determination of sound power levels and sound energy levels of noise sources
using sound pressure — Engineering methods for an essentially free field over a reflecting plane
ISO 80601-2-74:2021(E)
ISO 5356-1:2015, Anaesthetic and respiratory equipment — Conical connectors — Part 1: Cones and
sockets
ISO 5367:2014, Anaesthetic and respiratory equipment — Breathing sets and connectors
ISO 7396-1:2016+AMD1:2017, Medical gas pipeline systems — Part 1: Pipeline systems for compressed
medical gases and vacuum
ISO 9360-1:2000, Anaesthetic and respiratory equipment — Heat and moisture exchangers (HMEs) for
humidifying respired gases in humans — Part 1: HMEs for use with minimum tidal volumes of 250 ml
ISO 9360-2:2001, 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 14937:2009, Sterilization of health care products — General requirements for characterization of a
sterilizing agent and the development, validation and routine control of a sterilization process for medical
devices
ISO 16142-1:2016, Medical devices -- Recognized essential principles of safety and performance of medical
devices — Part 1: General essential principles and additional specific essential principles for all non-IVD
medical devices and guidance on the selection of standards
ISO 17664:2017, Processing of health care products — Information to be provided by the medical device
manufacturer for the processing of medical devices
ISO 18562-1:2017, Biocompatibility evaluation of breathing gas pathways in healthcare applications —
Part 1: Evaluation and testing within a risk management process
ISO 19223:2019, Lung ventilators and related equipment — Vocabulary and semantics
ISO 20417:2021, Medical devices — Information to be supplied by the manufacturer
ISO 23328-2:2002, Breathing system filters for anaesthetic and respiratory use — Part 2: Non-filtration
aspects
ISO 80369-1:2018, Small-bore connectors for liquids and gases in healthcare applications — Part 1:
General requirements
IEC 60601-1:2005+AMD1:2012+AMD2:2020, Medical electrical equipment — Part 1: General
requirements for basic safety and essential performance
IEC 60601-2-19:2020, Medical electrical equipment — Part 2-19: Particular requirements for the basic
safety and essential performance of infant incubators
IEC 62366-1:2015+AMD1:2020, Medical devices — Part 1: Application of usability engineering to
medical devices
IEC 62570:2014, Standard practice for marking medical devices and other items for safety in the
magnetic resonance environment
4 © ISO 2021 – All rights reserved

ISO 80601-2-74:2021(E)
201.3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 7396-1:2016,
ISO 9360-1:2000, ISO 17664:2017, ISO 18562-1:2017, ISO 19223:2019, ISO 23328-2:2002,
IEC 60601-1:2005+AMD1:2012+AMD2:2020, IEC 60601-1-2:2014+AMD1:2020,
IEC 60601-1-8:2006+AMD1:2012+AMD2:2020, IEC 60601-1-11:2015, IEC 62366-1:2015 and the
following apply.
ISO and IEC maintain terminological 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/
NOTE An alphabetized index of defined terms is found in Annex KK.
201.3.201
absolute humidity
mass of water vapour present in a unit volume of moist gas
Note 1 to entry: In respiratory applications absolute humidity is commonly represented in units of milligrams per
litre or grams per cubic metre.
Note 2 to entry: See also relative humidity.
[1]
[SOURCE: ISO 4135:— , 3.1.1.1]
201.3.202
active HME
humidifier where water, water vapour or heat is actively added to the HME to increase the humidity
level of the gas delivered from the HME to the patient
[1]
[SOURCE: ISO 4135:— , 3.7.2.3, modified —replaced 'device' with 'humidifier'.]
201.3.203
aerosol
suspension of liquid or solid particles in a gas
[1]
, 3.1.1.3]
[SOURCE: ISO 4135:—
201.3.204
airway device
device intended to provide a gas pathway to and from the patient’s trachea
[1]
[SOURCE: ISO 4135:— , 3.8.1.2]
201.3.205
body temperature pressure, saturated
BTPS
ambient atmospheric pressure, at a temperature of 37 °C, and a relative humidity (201.3.222) of 100 %
[1]
[SOURCE: ISO 4135:— , 3.1.1.7]
ISO 80601-2-74:2021(E)
201.3.206
breathing system
inspiratory and expiratory gas pathways through which gas flows at respiratory pressures and
continuously or intermittently in fluid communication with the patient’s respiratory tract during any
form of mechanical ventilation or respiratory therapy
[1]
[SOURCE: ISO 4135:— , 3.6.1.1, modified —deleted the notes to entry.]
201.3.207
breathing tube
non-rigid tube used to convey gases or vapours between components of a breathing system (201.3.206)
[1]
[SOURCE: ISO 4135:— , 3.1.4.4, modified —deleted “and/”.]
201.3.208
delivered gas temperature
temperature of the gas, or aerosol (201.3.203), or both, at the patient-connection port
[1]
[SOURCE: ISO 4135:— , 3.1.1.13]
201.3.209
flow-direction-sensitive component
component or accessory through which gas flow is in one direction only for proper functioning or
patient safety
[1]
[SOURCE: ISO 4135:— , 3.1.4.15, modified —replaced “must be” with “is”.]
201.3.210
gas intake port
port through which gas is drawn for use by the patient
[1]
[SOURCE: ISO 4135:— , 3.1.4.21
201.3.211
heated breathing tube controller
ME equipment which controls the temperature or the heating of a breathing tube
Note 1 to entry: A heated breathing tube controller can be either stand-alone or part of the humidifier.
201.3.212
humidification chamber
part of the humidifier (201.3.214) in which vaporization or nebulization takes place
[1]
[SOURCE: ISO 4135:— , 3.7.2.5]
201.3.213
humidification output
total mass of water vapour per unit volume of gas at the patient-connection port
Note 1 to entry: Humidification output is expressed under body temperature and pressure, saturated (BTPS)
conditions.
[1]
[SOURCE: ISO 4135:— , 3.7.2.6]
6 © ISO 2021 – All rights reserved

ISO 80601-2-74:2021(E)
201.3.214
humidifier
ME equipment that adds water in the form of droplets or vapour, or both, to the inspired gas
Note 1 to entry: This term includes vaporizing, bubble-through and ultrasonic humidifiers and active heat and
moisture exchangers (HMEs).
[1]
[SOURCE: ISO 4135:— , 3.7.2.1]
201.3.215
liquid container
part of a vaporizer, nebulizer or humidifier (201.3.214) which holds the liquid
Note 1 to entry: The liquid container can be accessible to the breathing gas.
Note 2 to entry: The liquid container can also be part of the humidification chamber.
Note 3 to entry: The liquid container can be detachable for filling.
[1]
[SOURCE: ISO 4135:— , 3.1.4.28]
201.3.216
liquid reservoir
reservoir from which the liquid container (201.3.215) can be replenished or which, in the absence of a
liquid container (201.3.215), supplies liquid directly to a vaporizer or aerosol (201.3.203) generator
[1]
[SOURCE: ISO 4135:— , 3.1.4.29, modified —replaced 'may' with 'can'.]
201.3.217
mask
device which provides a non-invasive interface between the patient’s airway and a patient-connection
port or other connection to a source of respirable gas
[1]
[SOURCE: ISO 4135:— , 3.8.6.4]
201.3.218
maximum operating pressure
maximum rated pressure in the humidification chamber (201.3.212) during normal use
201.3.219
measured gas temperature
temperature of the gas that the ME system is measuring and, if applicable, displaying
201.3.220
monitoring equipment
ME equipment or part that continuously or continually measures and indicates the value of a variable to
the operator
[1]
[SOURCE: ISO 4135:— , 3.11.1.3, modified —replaced 'user' with 'operator'.]
201.3.221
protection device
part or function of medical device or accessory that, without intervention by the operator, protects the
patient, other people or the environment from hazardous output due to incorrect delivery of energy or
substances
ISO 80601-2-74:2021(E)
[1]
[SOURCE: ISO 4135:— , 3.14.48, modified —replaced 'user' with 'operator'.]
201.3.222
relative humidity
water vapour pressure, expressed as a percentage of the saturation vapour pressure, at a particular
temperature
Note 1 to entry: See also absolute humidity.
[1]
[SOURCE: ISO 4135:— , 3.1.2.4]
201.3.223
set temperature
temperature at which the humidifier (201.3.214) attempts to maintain measured gas temperature
(201.3.219)
Note 1 to entry: The set temperature may be operator-adjustable.
201.3.224
standard temperature and pressure, dry
STPD
pressure of 101,325 kPa at an operating temperature of 20 °C, dry
[1]
[SOURCE: ISO 4135:— , 3.1.1.8]
201.3.225
validation
confirmation, through the provision of objective evidence, that the requirements for a specific intended
use or application have been fulfilled
Note 1 to entry: The objective evidence needed for a validation is the result of a test or other form of determination
such as performing alternative calculations or reviewing documents.
Note 2 to entry: The term “validated” is used to designate the corresponding status.
Note 3 to entry: The use conditions for validation can be real or simulated.
[3]
[SOURCE: ISO 9000:2015 , 3.8.13]
201.4 General requirements
Clause 4 of IEC 60601-1:2005+AMD1:2012+AMD2:2020 applies, except as follows.
201.4.3 Essential performance
IEC 60601-1:2005+AMD1:2012, 4.3 applies, except as follows.
Additional subclause:
201.4.3.101 * Additional requirements for essential performance
Additional essential performance requirements are found in the subclauses listed in Table 201.101.
8 © ISO 2021 – All rights reserved

ISO 80601-2-74:2021(E)
Table 201.101 — Distributed essential performance requirements
Requirement Subclause
a
For category 1 or category 3 humidifiers, delivery of humidification output 201.12.1.101

or generation of a technical alarm condition
measured gas temperature 201.12.1.102
low humidification output 201.12.4.102
For category 2 humidifiers for the purposes of this document, category 2 —
humidifiers are considered to not have essential performance. Notwithstanding
this fact, when this document refers to essential performance as acceptance
a
criteria, the delivery of humidification output is evaluated.
a
Subclause 202.8.1.101 indicates methods of evaluating delivery of humidification output as acceptance criteria following
specific tests required by this document.

201.4.6 * ME equipment or ME system parts that contact the patient
Amendment (add at end of 4.6 prior to the compliance check):
aa)  The humidifier or its parts or accessories that can come into contact with the patient shall be
subject to the requirements for applied parts according to this subclause.
Additional subclauses:
201.4.11.101 * Additional requirements for pressurized gas input
201.4.11.101.1 Overpressure requirement
a) If the humidifier is intended to be connected to a medical gas pipeline system conforming with
ISO 7396-1:2016+AMD1:2017, then it:
1) shall operate and meet the requirements of this document throughout its rated range of input
pressure;
2) shall not cause an unacceptable risk under the single fault condition of 1 000 kPa.
NOTE 1 An internal pressure regulator can be needed to accommodate the single fault condition of
maximum input pressure, as well as the rated range of input pressure.
NOTE 2 Under the single fault condition of overpressure, it is desirable for gas to continue to flow to
the breathing system. Under this condition, the flowrate from the humidifier is likely to be outside of its
specification.
b) If the humidifier has a maximum rated input pressure in excess of 600 kPa, the humidifier shall not
cause an unacceptable risk under the single fault condition of twice the maximum rated input
pressure.
Check conformance by functional testing in normal use and under normal condition with the most adverse
operating settings, by functional testing in single fault condition and inspection of the risk management
file.
ISO 80601-2-74:2021(E)
201.4.11.101.2 Compatibility requirement
If the humidifier is intended to be directly connected to a medical gas pipeline system conforming with
ISO 7396-1:2016+AMD1:2017 then:
a) the rated range of input pressure shall cover the range spec
...