EN ISO 8835-2:2007

SLOVENSKI STANDARD
01-april-2008
1DGRPHãþD
SIST EN 740:2000
SIST EN 740:2000/A1:2005
SIST EN 740:2000/AC:2000
Inhalacijski anestezijski sistemi - 2. del: Anestezijski dihalni sistemi za odrasle
(ISO 8835-2:2007)
Inhalational anaesthesia systems - Part 2: Anaesthetic breathing systems (ISO 8835-
2:2007)
Systeme für die Inhalationsanästhesie - Teil 2: Anästhesie-Atemsysteme (ISO 8835-
2:2007)
Systemes d'anesthésie par inhalation - Partie 2: Systemes respiratoires d'anesthésie
(ISO 8835-2:2007)
Ta slovenski standard je istoveten z: EN ISO 8835-2:2007
ICS:
11.040.10
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 8835-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2007
ICS 11.040.10 Supersedes EN 740:1998
English Version
Inhalational anaesthesia systems - Part 2: Anaesthetic breathing
systems (ISO 8835-2:2007)
Systèmes d'anesthésie par inhalation - Partie 2: Systèmes Systeme für die Inhalationsanästhesie - Teil 2: Anästhesie-
respiratoires d'anesthésie (ISO 8835-2:2007) Atemsysteme (ISO 8835-2:2007)
This European Standard was approved by CEN on 9 June 2007.
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 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 Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2007 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 8835-2:2007: E
worldwide for CEN national Members.

Foreword
This document (EN ISO 8835-2:2007) 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 February 2008, and conflicting national
standards shall be withdrawn at the latest by May 2009.
This document has been prepared under a mandate given to CEN by the European
Commission and the European Free Trade Association, and supports essential requirements
of EU Directive(s).
For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of
this document.
Other European Standards relating to anaesthetic workstations and their components
prepared by CEN/TC 215 which together with EN 60601-2-13:2006, replace appropriate
portions of EN 740:1998, are:
– EN ISO 8835-2:2007, Inhalational anaesthesia systems – Part 2: Anaesthetic breathing
systems (ISO 8835-2:2007)
– EN ISO 8835-3:2007, Inhalational anaesthesia systems – Part 3: Transfer and receiving
systems of active anaesthetic gas scavenging systems (ISO 8835-3:2007)
– EN ISO 8835-4:2004, Inhalational anaesthesia systems – Part 4: Anaesthetic vapour
delivery devices (ISO 8835-4:2004)
– EN ISO 8835-5:2004, Inhalational anaesthesia systems – Part 5: Anaesthetic ventilators
(ISO 8835-5:2004)
Attention is also drawn to ISO/TS 18835:2004, Inhalational anaesthesia systems — Draw-
over vaporizers and associated equipment.
Annex RR of EN 740:1998 (Method of test for draw-over vaporizers used with emergency
anaesthetic equipment) is not superseded.
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.
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, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United
Kingdom.
Endorsement notice
The text of ISO 8835-2:2007 has been approved by CEN as EN ISO 8835-2:2007 without any
modifications.
ANNEX ZA
(informative)
Relationship between this standard and the Essential
Requirements of EU Directive 93/42/EEC

This European Standard has been prepared under a mandate given to CEN by the European
Commission and the European Free Trade Association to provide a means to conforming to
Essential Requirements of the New Approach Directive 93/42/EEC, Council Directive of 14
June 1993 on the approximation of the laws of the Member States concerning medical
devices (Medical Device Directive).

Once this European Standard is cited in the Official Journal of the European Communities
under that Directive and has been implemented as a national standard in at least one
Member State, compliance with the clauses of this European Standard given in Table ZA.1
confers, within the limits of the scope of this European Standard, a presumption of conformity
with the corresponding Essential Requirements of that Directive and associated EFTA
regulations.
Table ZA.1 — Correspondence between this International Standard and EU Directive
93/42/EEC
Clause(s)/sub-clause(s) of Essential requirements (ERs) of EU Qualifying remarks/Notes
this International Standard Directive 93/42/EEC
All 1 to 6
4.1 1 to 6, and 7
4.2 1 to 6, and 9.2
4.3 1 to 6, and 12.6
4.4
5 1 to 6, 9 and 12.7
6 1 to 6, 9 and 12.7
7 1 to 6, 9.2 and 12.7
8.1 1 to 6, 9 and 12.7
8.2 1 to 6, 9 and 12.9
8.2.2 1 to 6, and 9
8.2.3 1 to 6, 9 and 12.7
9.1 1 to 6, and 9
9.2 1 to 6, 9 and 12.7
9.3 1 to 6, 9, 12.7 and 12.9
9.4 1 to 6, and 9
9.5.1 1 to 6, and 9
9.5.2 1 to 6, and 9
9.5.3 1 to 6, and 9
9.5.4 1 to 6, and 9
9.5.5 1 to 6, and 9
10 1 to 6, 9 and 10
11 1 to 6, and 9
12 1 to 6, 9 and 13
13 1 to 6, 9 and 13
Warning – Other requirements and other EU Directives may be applicable to the
product(s) falling within the scope of this standard.
INTERNATIONAL ISO
STANDARD 8835-2
Third edition
2007-08-15
Inhalational anaesthesia systems —
Part 2:
Anaesthetic breathing systems
Systèmes d'anesthésie par inhalation —
Partie 2: Systèmes respiratoires d'anesthésie

Reference number
ISO 8835-2:2007(E)
©
ISO 2007
ISO 8835-2:2007(E)
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ii © ISO 2007 – All rights reserved

ISO 8835-2:2007(E)
Contents Page
Foreword. v
Introduction . vi
* 1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 2
4 General. 3
4.1 Materials . 3
4.2 Anaesthetic breathing system component packaging . 3
4.3 Electrical requirements . 3
4.4 Alternative test methods. 4
5 Connection ports . 4
5.1 Patient connection port. 4
5.2 Y-Piece . 4
5.3 Exhaust connection port. 4
5.4 Interchangeable non-rebreathing exhaust valves. 4
* 5.5 Reservoir bag connection port. 4
5.6 Anaesthetic ventilator connection port. 5
5.7 Connection ports of interchangeable anaesthetic breathing system components. 5
* 5.8 Inspiratory and expiratory connection ports of an interchangeable circle absorber
assembly. 5
5.9 Other connection ports . 5
6 Reservoir bag/anaesthetic ventilator selector switch. 5
7 Complete anaesthetic breathing system either supplied assembled or assembled in
accordance with the manufacturer’s instructions . 5
* 7.1 Leakage. 5
* 7.2 Inspiratory and expiratory pressure/flow characteristics . 6
8 Interchangeable anaesthetic breathing system components — Exhaust valves . 6
8.1 Direction of movement of controls . 6
8.2 Pressure/flow characteristics. 6
8.3 Opening pressure . 6
8.4 Leakage. 6
9 Circle absorber assemblies . 6
9.1 Construction. 6
9.2 Absorbent bypass mechanism. 7
9.3 Pressure/flow characteristics. 7
9.4 Inspiratory and expiratory valves . 7
10 Pressure monitoring and limitation . 8
10.1 Pressure monitoring. 8
10.2 Pressure-limiting device . 8
* 11 Location of components in an anaesthetic breathing system containing a circle absorber
assembly (as defined in 3.3) . 8
11.1 Exhaust valve . 8
11.2 Reservoir bag connection port. 8
11.3 Fresh gas inlet. 8
11.4 Inspiratory and expiratory valves . 8
12 Marking . 9
ISO 8835-2:2007(E)
12.1 Marking of complete anaesthetic breathing systems and anaesthetic breathing system
components. 9
12.2 Marking of packages. 10
13 Information to be provided by the manufacturer or supplier. 10
13.1 General . 10
13.2 For anaesthetic breathing systems supplied complete. 10
13.3 For anaesthetic breathing system components . 11
Annex A (normative) Typical test arrangements and methods . 13
Annex B (informative) Rationale . 18
Annex C (informative) Environmental aspects . 20
Annex D (normative) Antistatic requirements . 21
Bibliography . 22

iv © ISO 2007 – All rights reserved

ISO 8835-2:2007(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 8835-2 was prepared by Technical Committee ISO/TC 121, Anaesthetic and respiratory equipment,
Subcommittee SC 1, Breathing attachments and anaesthetic machines.
This third edition cancels and replaces the second edition (ISO 8835-2:1999), which has been technically
revised.
ISO 8835 consists of the following parts, under the general title Inhalational anaesthesia systems:
⎯ Part 2: Anaesthetic breathing systems
⎯ Part 3: Transfer and receiving systems of active anaesthetic gas scavenging systems
⎯ Part 4: Anaesthetic vapour delivery devices
⎯ Part 5: Anaesthetic ventilators
ISO 8835-2:2007(E)
Introduction
An anaesthetic breathing system comprises an assembly of tubes and connectors and may include valves, a
reservoir bag and a circle absorber assembly. Other items of equipment (e.g. humidifiers, filters, spirometers,
thermometers, gas analysers) may be incorporated into an anaesthetic breathing system.
Its function is to convey mixtures of gases to and from the patient.
Annex A gives typical test arrangements and methods. Annex B gives the rationale for some of the
requirements found within this part of ISO 8835.
Annex B contains rationale statements for some of the requirements of this part of ISO 8835. The clauses and
subclauses marked with an asterix (*) before their number have corresponding rationale contained in Annex B,
included to provide additional insight into the reasoning that led to the requirements and recommendations
that have been incorporated in this International Standard.
Annex C lists the clauses of this part of ISO 8835 that address the environmental aspects of the device.

vi © ISO 2007 – All rights reserved

INTERNATIONAL STANDARD ISO 8835-2:2007(E)

Inhalational anaesthesia systems —
Part 2:
Anaesthetic breathing systems
* 1 Scope
This part of ISO 8835 specifies requirements for anaesthetic breathing systems that are supplied either
assembled by the manufacturer or for assembly by the user in accordance with the manufacturer's
instructions.
It also covers circle absorber assemblies, exhaust valves, inspiratory and expiratory valves and, in some
designs, those parts of an anaesthetic breathing system that are incorporated within an inhalation anaesthetic
system, including the expiratory gas pathway of an anaesthetic ventilator.
This part of ISO 8835 does not cover the performance of anaesthetic breathing systems regarding the
elimination of expired carbon dioxide since this is complex and depends on the interaction of the patient, the
fresh gas flow, the carbon dioxide absorbent and the anaesthetic breathing system itself.
This part of ISO 8835 does not apply to anaesthetic breathing systems intended for use with flammable
anaesthetic agents/gases as determined by Annex DD of IEC 60601-2-13:2003.
2 Normative references
The following referenced documents are indispensable for the application 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 594-2, Conical fittings with a 6 % (Luer) taper for syringes, needles and certain other medical
equipment — Part 2: Lock fittings
ISO 2878:2005, Rubber — Antistatic and conductive products — Determination of electrical resistance
ISO 4135, Anaesthetic and respiratory equipment — Vocabulary
ISO 5356-1, Anaesthetic and respiratory equipment — Conical connectors — Part 1: Cones and sockets
ISO 5356-2, Anaesthetic and respiratory equipment — Conical connectors — Part 2: Screw-threaded weight-
bearing connectors
ISO 5362, Anaesthetic reservoir bags
ISO 5367, Breathing tubes intended for use with anaesthetic apparatus and ventilators
ISO 7000:2004, Graphical symbols for use on equipment — Index and synopsis
IEC 60601-1, Medical electrical equipment — Part 1: General requirements for basic safety and essential
performance
ISO 8835-2:2007(E)
IEC 60601-1-2, Medical electrical equipment — Part 1-2: General requirements for safety — Collateral
standard: Electromagnetic compatibility — Requirements and tests
IEC 60601-2-13:2003, Medical electrical equipment — Part 2-13: Particular requirements for the safety and
essential performance of anaesthetic systems
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4135 and IEC 60601-2-13 and the
following apply.
3.1
anaesthetic breathing system
ABS
those inspiratory and expiratory pathways through which gas flows at respiratory pressure between the fresh
gas inlet (3.6), the patient connection port (3.9) and the exhaust valve (3.5) or exhaust port (3.4)
3.2
circle absorber assembly
that part of a circle breathing system (3.3) which comprises one or more carbon-dioxide-absorbent
containers, inspiratory and expiratory valves or other means of ensuring unidirectional gas flow, two ports for
connection to breathing tubes, a fresh gas inlet (3.6), a reservoir bag port and/or an anaesthetic ventilator
port
3.3
circle breathing system
anaesthetic breathing system (3.1) in which the direction of gas flow through inspiratory and expiratory
pathways is unidirectional and in which the two pathways form a circle
3.4
exhaust port
that port through which waste gas(es) are discharged to the atmosphere or to an anaesthetic gas scavenging
system (AGSS)
3.5
exhaust valve
valve through which waste gas(es) are discharged to the atmosphere or to an AGSS
NOTE Such a valve can or might not be an adjustable pressure-limiting (APL) valve.
3.6
fresh gas inlet
that port through which fresh gas is supplied to the anaesthetic breathing system (3.1)
3.7
interchangeable component
operator-detachable anaesthetic breathing system component designed to be used with specified equipment
from different manufacturers
3.8
non-rebreathing exhaust valve
exhaust valve (3.5) with three ports, namely an inlet port for connection to a breathing tube or ABS
component, a patient connection port (3.9) and an exhaust port (3.4), the function of the valve being to
prevent exhaled gas from re-entering the anaesthetic breathing system (3.1)
2 © ISO 2007 – All rights reserved

ISO 8835-2:2007(E)
3.9
patient connection port
that port at the patient end of an anaesthetic breathing system (3.1) intended for connection to devices such
as a tracheal or tracheostomy tube connector, or the connector to a face mask or supraglottic device
3.10
Y-piece
three-way connector with a patient connection port (3.9) and two ports for connection to breathing tubes
4 General
4.1 Materials
All components of an anaesthetic breathing system shall be designed and manufactured in such a way as to
reduce to a minimum the risks posed by substances leaching from them.
When selecting materials for components of anaesthetic breathing systems, manufacturers should take
particular care to ensure compatibility of the materials with the gases and anaesthetic agents with which they
are intended to come into contact.
4.2 Anaesthetic breathing system component packaging
Anaesthetic breathing system components shall be packaged in such a way as to minimize the risk of
incomplete removal of the packaging before use.
NOTE 1 This is to prevent accidental retention of the packaging (e.g. transparent wrapper, caps, lids, covers, etc.) and
to ensure its removal by the operator prior to use.
NOTE 2 Attention is drawn to IEC 60601-1-6 which requires a usability engineering process. Completion of this
process will ensure that such risks are minimized to an acceptable level.
4.3 Electrical requirements
* 4.3.1 General
If the anaesthetic breathing system incorporates electrically powered components, the system shall comply
with applicable parts of IEC 60601-1 and IEC 60601-1-2.
Anaesthetic breathing systems and anaesthetic breathing system components which incorporate RF wireless
technology should be assessed for the following risks:
⎯ electromagnetic compatibility (EMC);
⎯ performance of wireless functions;
⎯ wireless coexistence;
⎯ wireless quality of service;
⎯ integrity of data transmitted wirelessly;
⎯ security of data transmitted wirelessly;
⎯ wireless network access.
ISO 8835-2:2007(E)
4.3.2 Electrical conductivity
Anaesthetic breathing systems and anaesthetic breathing system components marked as “antistatic” or
“conductive” shall comply with Annex D when tested as described in ISO 2878.
NOTE See 12.1 h) for marking requirements.
4.4 Alternative test methods
The manufacturer may use type tests different from those described in this part of ISO 8835 if an equivalent
degree of compliance can be demonstrated. However, in the event of dispute, the test arrangements and
methods described in this part of ISO 8835 should be used as the reference methods.
5 Connection ports
5.1 Patient connection port
The patient connection port shall be a coaxial male 22 mm/female 15 mm conical connector complying with
ISO 5356-1.
NOTE The patient connection port can be designed so that it will swivel.
5.2 Y-Piece
The machine ends of a Y-piece not permanently attached to breathing tubes shall be either 22 mm male
conical connectors complying with ISO 5356-1 or other connectors compatible with breathing tubes complying
with ISO 5367.
5.3 Exhaust connection port
The exhaust connection port shall be one of the following:
a) a 30 mm male conical connector complying with ISO 5356-1, for connection to an interchangeable AGS
transfer and receiving system and with means of preventing connection of the orifice to any anaesthetic
breathing system component;
b) a proprietary fitting incompatible with connectors complying with ISO 5356-1 and breathing tubes
complying with ISO 5367, for connection to a non-interchangeable anaesthetic gas scavenging (AGS)
transfer and receiving system;
c) non-operator-detachable from the anaesthetic gas scavenging transfer system.
NOTE See 12.1 c) for marking requirements.
5.4 Interchangeable non-rebreathing exhaust valves
The inlet connection port shall be a female 22 mm conical connection complying with ISO 5356-1.
The patient connection port shall comply with 5.1
The exhaust connection port shall comply with 5.3
* 5.5 Reservoir bag connection port
The reservoir bag connection port shall be compatible with a reservoir bag complying with ISO 5362 and a
breathing tube complying with ISO 5367.
4 © ISO 2007 – All rights reserved

ISO 8835-2:2007(E)
This connection shall be within 20° of the vertical axis.
NOTE See 12.1 d) for marking requirements.
5.6 Anaesthetic ventilator connection port
If a connection port for an interchangeable anaesthetic ventilator is provided, it shall be a 22 mm male conical
connector complying with ISO 5356-1 or ISO 5356-2
If a connection port for a manufacturer-specific anaesthetic ventilator is provided, it shall be a proprietary
fitting incompatible with connectors complying with ISO 5356-1 and breathing tubes complying with ISO 5367.
NOTE See 12.1 e) for marking requirements.
5.7 Connection ports of interchangeable anaesthetic breathing system components
Interchangeable anaesthetic breathing system components shall have connection ports with conical
connectors of either 15 mm or 22 mm complying with ISO 5356-1 or ISO 5356-2.
NOTE To prevent unintended disengagement of conical connection, 22 mm latching connectors complying with
ISO 5356-1 can be used.
* 5.8 Inspiratory and expiratory connection ports of an interchangeable circle absorber
assembly
If these connection ports are operator-detachable, the inspiratory and the expiratory ports of a circle absorber
assembly shall have 22 mm male conical connectors with or without coaxial 15 mm female conical connectors,
both complying with ISO 5356-1 or ISO 5356-2. The axis of these ports shall be either horizontal or within
± 50° of the horizontal plane.
5.9 Other connection ports
Connection ports used for specific purposes (e.g. pressure measurement, gas sample return, etc.) shall not be
compatible with ISO 5356-1, ISO 5356-2 or ISO 594-2 connectors. The connection ports shall be provided
with a means of securing closure when not in use. The means of closure shall be non-detachable from the
component.
NOTE 1 Particular device standards (e.g. ISO 8185 for humidifiers) might contain requirements for specific ports
(e.g. temperature probe) when such equipment is added to the anaesthetic breathing system.
NOTE 2 For gas sample return port, see 12.1 g) for marking requirements.
6 Reservoir bag/anaesthetic ventilator selector switch
If a switch is provided to change from the reservoir bag to the anaesthetic ventilator and vice versa, it shall be
bi-stable.
NOTE See 12.1 i) for marking requirements.
7 Complete anaesthetic breathing system either supplied assembled or assembled
in accordance with the manufacturer’s instructions
* 7.1 Leakage
The leakage from an anaesthetic breathing system shall not exceed 150 ml/min (15,2 kPa × l/min) at 3,0 kPa
(30 cm H O) internal pressure.
ISO 8835-2:2007(E)
NOTE 1 For some uses the leakage limit of 150 ml/min might not be appropriate.
NOTE 2 See Annex A for typical test arrangement and method.
* 7.2 Inspiratory and expiratory pressure/flow characteristics
The pressure (positive/sub-atmospheric) generated at the patient connection port shall not exceed 0,6 kPa
(6 cm H O) at the peak flow of 60 l/min when connected to the anaesthesia system or suitable test rig
supplying a fresh gas flow of 10 l/min (± 1 l/min) or the maximum fresh gas inlet flow specified by the
manufacturer.
The manufacturer shall disclose the pressure/flow characteristics of the anaesthetic breathing system,
including the pressure at 60 l/min [see 13.2 b)].
NOTE See Annex A for typical test arrangement and method.
8 Interchangeable anaesthetic breathing system components — Exhaust valves
8.1 Direction of movement of controls
For operator-adjustable exhaust valves with rotary controls, the movement of the control in a clockwise
direction shall progressively increase the opening pressure.
NOTE In some designs, movement of the control to a fully clockwise position might not close the valve completely.
8.2 Pressure/flow characteristics
For exhaust valves supplied separately, the manufacturer shall disclose the pressure-flow characteristics of
the valve, including the opening pressure and the pressure drop with any valve control fully open at a flow of
30 l/min [see 13.3.2 b)].
8.3 Opening pressure
For exhaust valves supplied separately, the manufacturer shall disclose the opening pressure of the valve
under wet conditions [see 13.3.2 c)].
8.4 Leakage
For exhaust valves supplied separately, which can be fully closed, the manufacturer shall disclose the leakage
to atmosphere in the fully closed position at a pressure of 3 kPa (30 cm H O).
9 Circle absorber assemblies
9.1 Construction
Circle absorber assemblies supplied separately shall incorporate inspiratory and expiratory valves or other
means of ensuring unidirectional gas flow. If these valves or means can be detached from the circle absorber
assembly, the method of attachment to the latter shall be by means of connectors which are
non-interchangeable with each other and which are not compatible with any of the connectors specified in
ISO 5356-1 and ISO 5356-2.
NOTE See 12.1 l) for marking requirements.
The design of the carbon dioxide-absorbent container shall enable the colour change of the absorbent to be
clearly visible.
It should be possible to change the absorbent without opening the gas pathway to the atmosphere.
6 © ISO 2007 – All rights reserved

ISO 8835-2:2007(E)
9.2 Absorbent bypass mechanism
9.2.1 If a means of excluding the absorbent from the gas pathway is provided, the operation of which is
actuated automatically by removing the absorbent container(s), the circle absorber assembly shall meet the
leakage requirements of 7.1 and the pressure/flow requirements of 7.2, both with the container(s) in place and
with them removed.
9.2.2 When the mechanism for excluding the absorbent is operator-controlled, the control shall have a
means of preventing accidental movement and shall be marked in accordance with 12.1 j). The “off” indicator
shall mean that the gas does not pass through the absorbent and the indicator shall be visible to the operator
from the normal operating position.
9.2.3 Unless the absorber bypass mechanism is intended to function at one or more intermediate setting(s),
the control shall have only “on” and “off” positions and shall be bi-stable. The circle absorber assembly shall
meet the leakage requirements of 7.1 and the pressure/flow requirements of 7.2 with the control in the “on”
and “off” positions.
9.2.4 For a bypass mechanism intended to function at one or more intermediate setting(s), the control shall
so indicate and the circle absorber assembly shall meet the leakage requirements of 7.1 and the pressure/flow
requirements of 7.2 in the “on” and “off” positions and at any intermediate setting of the control.
9.2.5 For a circle absorber assembly with an operator-controlled absorbent bypass mechanism, when the
control is in the “off” position, it shall be possible to change the absorbent without opening the gas pathway to
the atmosphere.
9.3 Pressure/flow characteristics
Circle absorber assemblies supplied separately, when assembled with other components according to the
manufacturer's instructions to form a complete anaesthetic breathing system, shall meet the leakage and
pressure/flow requirements of Clause 7.
NOTE See Annex A for typical test arrangement and method.
9.4 Inspiratory and expiratory valves
9.4.1 General
Unless a means of indicating a malfunction is provided, inspiratory and expiratory valves shall be designed
and located such that their action is visible to the operator.
9.4.2 Pressure/flow characteristics
For inspiratory and expiratory valves supplied as separate components, the manufacturer shall disclose the
pressure-flow characteristics of the valves under both wet and dry conditions, including the pressure drop at a
flow of 60 l/min [see 13.3.4 a)].
At a flow of 20 ml/min the pressure to open a dry valve shall not exceed 0,12 kPa (1,2 cm H O).
NOTE See Annex A for typical test arrangement and method.
* 9.4.3 Reverse flow and dislocation
The reverse flow through the valve shall not exceed 60 ml/min at a pressure of up to 0,5 kPa (5,0 cm H O)
NOTE 1 Typically the most significant reverse flow with disc-type valves is at pressures of less than 0,05 kPa
(0,5 cm H O), whereas with flap valves it can be at a higher pressure.
The valve disc or flap shall not become dislocated on application of a reverse pressure of 5 kPa (50 cm H O)
and the reverse flow through the valve shall not exceed 60 ml/min at a pressure of up to 0,5 kPa (5,0 cm H O)
NOTE 2 See Annex A for typical test arrangement and method.
ISO 8835-2:2007(E)
10 Pressure monitoring and limitation
10.1 Pressure monitoring
10.1.1 The anaesthetic breathing system shall incorporate either a pressure-measuring device or a means
for connection to a pressure-measuring device.
10.1.2 If a pressure-measuring device is provided, it shall be marked in kilopascals.
NOTE Additional units (e.g. cm H O) can be used.
The pressure-measuring device shall have a minimum range from − 1 kPa (− 10 cm H O) to + 6 kPa
(+ 60 cm H O).
Under conditions of dynamic testing, readings shall be within a tolerance of ± (4 % of the full scale reading
+ 4 % of the reading).
10.1.3 To permit cleaning and disinfection or sterilization of the anaesthetic breathing system components,
the pressure-measuring device shall either be detachable or be capable of being cleaned and disinfected or
sterilized.
10.2 Pressure-limiting device
If a pressure-limiting device is provided, then both during normal operating conditions and under single fault
conditions the pressure at the patient connection port shall not exceed 12,5 kPa (125 cmH O).
NOTE A reservoir bag complying with ISO 5362 may be considered as a maximum pressure-limiting device for an
anaesthetic system without an anaesthetic ventilator or when the anaesthetic ventilator is in the manual or spontaneous
ventilation mode.
* 11 Location of components in an anaesthetic breathing system containing a circle
absorber assembly (as defined in 3.3)
NOTE For circle absorber assemblies integrated within an anaesthesia system these restrictions on the location of
components might not apply.
11.1 Exhaust valve
An exhaust valve shall not be located between the inspiratory valve and the Y-piece.
11.2 Reservoir bag connection port
The port for connection to a reservoir bag shall not be on the patient side of the inspiratory or expiratory
valve(s).
11.3 Fresh gas inlet
The fresh gas inlet shall not be on the patient side of the inspiratory or expiratory valve.
The fresh gas inlet should preferably be between the carbon dioxide absorbent container and the inspiratory
valve.
11.4 Inspiratory and expiratory valves
Inspiratory valves and expiratory valves shall not be located in the Y-piece.
8 © ISO 2007 – All rights reserved

ISO 8835-2:2007(E)
12 Marking
12.1 Marking of complete anaesthetic breathing systems and anaesthetic breathing system
components
Complete anaesthetic breathing systems and components shall be marked with the following as appropriate:
a) the name and/or trademark of the manufacturer or supplier;
b) the production identifier (e.g. batch or lot);
c) for an exhaust connection port complying with 5.3, the word “EXHAUST” and/or “AGS” or the equivalent
in the national language or an appropriate symbol;
d) for a reservoir bag connection port complying with 5.5, the word “BAG” or the equivalent in the national
language or an appropriate symbol;
e) for an anaesthetic ventilator connection port complying with 5.6, the word “VENTILATOR” or the
equivalent in the national language or an appropriate symbol;
f) for operator-interchangeable flow-direction sensitive components, an indication of the direction of gas flow;
g) for a gas sampling return connection port complying with 5.9, the words “GAS SAMPLE RETURN” or the
equivalent in the national language or symbol from ISO 7000;
h) the word “ANTISTATIC” or “CONDUCTIVE” for anaesthetic breathing systems and integrally attached
non-metallic components made of antistatic or conductive materials;
NOTE They can also bear an indelible yellow-coloured mark.
i) for a switch provided to change from reservoir bag to anaesthetic ventilator and vice versa, complying
with Clause 6, the words “BAG” and “VENTILATOR” or the equivalent in the national language and/or
appropriate symbols;
j) for an operator-controlled mechanism for excluding the absorbent from the gas pathway, the control shall
be marked with the words “on” and “off”, or the equivalent in the national language, and/or with symbols
shown in Figure 1;
NOTE The words “on” and “off” can be preceded by the word “absorber”.
k) for single use devices, the words “FOR SINGLE USE” or the equivalent in the national language or
symbol No. 1051 of ISO 7000:2004 (indicating “do not re-use”);
l) inspiratory and expiratory ports of a circle absorber assembly, with an arrow to indicate the direction of
gas flow.
a)  Symbol for “absorber on” b)  Symbol for “absorber off”
Figure 1 — Absorbent bypass control markings
ISO 8835-2:2007(E)
12.2 Marking of packages
Packages containing complete anaesthetic breathing system or anaesthetic breathing system components
shall be marked with the following as appropriate:
a) the name and/or trademark of the manufacturer or supplier;
b) the production identifier (e.g. batch or lot);
c) a description of the contents;
d) the words “FOR SINGLE USE” or the equivalent in the national language or symbol No. 1051 of
ISO 7000:2004 (indicating “do not re-use”);
e) the word “STERILE” or a symbol;
f) the word “ANTISTATIC” or “CONDUCTIVE”.
13 Information to be provided by the manufacturer or supplier
13.1 General
The following information shall be provided as appropriate by the manufacturer for complete anaesthetic
breathing systems and for anaesthetic breathing system components supplied separately:
a) installation instructions;
b) warnings, cautions and safety notices;
c) the meaning or a description of all symbols, abbreviations and figures;
d) explanation of the function of controls;
e) a description of all the operational modes in which the anaesthetic breathing system or anaesthetic
breathing system component is intended to be used;
f) a statement of known compatibility with gases and anaesthetic agents, and a statement regarding
suitability for use with flammable anaesthetic agents;
g) where appropriate, an indication of the date by which the anaesthetic breathing system or ABS
component can be used in safety, e
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