ISO 17420-5:2021

INTERNATIONAL ISO
STANDARD 17420-5
First edition
2021-06
Respiratory protective devices —
Performance requirements —
Part 5:
Special application fire and rescue
services - Supplied breathable gas
RPD and filtering RPD
Appareils de protection respiratoire — Exigences de performances —
Partie 5: Applications particulières pour lutte contre les feux et
opérations de sauvetage - APR alimentés en gaz respirable et APR
filtrants
Reference number
©
ISO 2021
© 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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, abbreviations and symbols . 2
3.1 Terms and definitions . 2
3.2 Abbreviated terms . 3
4 Classification overview . 3
4.1 General . 3
4.2 Supplied breathable gas RPD. 3
4.3 Filtering RPD . 4
5 General requirements for RPD . 4
6 Basic requirements for supplied breathable gas RPD and filtering RPD .4
7 Special application for fire and rescue services filtering and supplied breathable gas RPD 5
7.1 Special application for fire and rescue services RPD – Requirement matrices . 5
7.1.1 General. 5
7.1.2 Supplied breathable gas fire and rescue services RPD . 5
7.1.3 Filtering fire and rescue services RPD . 7
7.2 Requirements for special application fire and rescue services RPD . 9
7.2.1 Thermal Requirements . 9
7.2.2 Resistance to flame .11
7.2.3 Radiant heat .12
7.2.4 Resistance to hot particles (embers/sparks/ash) – Supplied breathable
gas RPD and filtering RPD .13
7.2.5 Chemical resistance of materials .13
7.2.6 Hazardous materials – Supplied breathable gas RPD .14
7.2.7 Contact with hot and cold surfaces generated by the RPD .15
7.2.8 Avoidance of frictional sparks – Supplied breathable gas RPD and filtering RPD 16
7.2.9 Visor after chemical exposure – Supplied breathable gas RPD and filtering RPD 16
7.2.10 Mechanical requirement .17
7.2.11 Requirements for audible warning devices – Supplied breathable gas RPD .18
7.2.12 Practical performance requirements .19
7.2.13 Eye irritation (external) .19
7.2.14 Operation during submersion – Supplied breathable gas RPD .19
7.2.15 Resistance to water splash – Filtering RPD .20
7.2.16 Communication performance (speaking and hearing) – Supplied
breathable gas RPD and filtering RPD .20
7.2.17 Requirements for RPD used in explosive atmospheres and
electromagnetic compatibility – Supplied breathable gas RPD and filtering
RPD .20
7.2.18 RPD class FF1 . . .21
7.2.19 Exposure to dust .22
7.3 Pre-conditioning of supplied breathable gas RPD and filtering RPD .22
7.3.1 General.22
7.3.2 Exposure to vibration and shock – Supplied breathable gas RPD and
filtering RPD.22
7.3.3 Exposure to impact from drop – Filtering RPD and replaceable filters .23
7.3.4 Exposure to impact from drop — Supplied breathable gas RPD .23
7.3.5 Enhanced resistance to corrosion — Constant exposure .24
8 Testing .24
8.1 General .24
8.2 Inspection .24
8.3 Testing of leak tightness using positive pressure .25
8.4 Testing of hose permeation .25
8.4.1 Hose material .25
8.4.2 Sampling air .25
8.4.3 Test equipment .25
9 Marking .28
10 Information supplied by the manufacturer .28
Bibliography .29
iv © ISO 2021 – All rights reserved

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 on 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 the following
URL: www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 94, Personal safety - Personal protective
equipment, Subcommittee SC 15, Respiratory protective devices in close cooperation with Subcommittee
SC 14, Firefighters' personal equipment.
A list of all parts in the ISO 17420 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.
Introduction
This document describes requirements for RPD used for special applications fire and rescue services
and its elements and components.
Some test methods are described. For other test methods references are given to the ISO 16900 series
"Methods of test and test equipment" or other test methods not developed by ISO/TC 94/SC 15.
The sequence of testing follows the principle to minimize the necessary number of samples by carrying
out destructive tests at the end. For safety reason it also includes that tests with test subjects are only
carried out after the test samples have shown their safe performance in other tests.
To apply this standard properly consider the following:
— ISO 17420-1 specifies the general requirements for supplied breathable gas RPD and filtering
RPD and cannot be used as a standard for "certification" alone. Therefore, compliance with the
requirements and tests of ISO 17420-2 or ISO 17420-4 is required in addition.
The structure of the standards is as follows:
ISO 17420-1 specifies the general requirements for RPD.
ISO 17420-2 and ISO 17420-4 gives requirements for filtering or supplied breathable gas RPD and give
information if any of the general requirements in Part 1 needs an addition.
EXAMPLE for ISO 17420-4 5.8.1 General
ISO 17420-1:2021, 5.8.1 applies with the following in addition:
ISO 17420-5 to ISO 17420-9 gives requirements for filtering or supplied breathable gas RPD — Special
application and some of the requirements will supersede requirements specified in ISO 17420-2 or
ISO 17420-4.
EXAMPLE for ISO 17420-5 7.2.1.3 Temperature of operation – level 0 — Supplied breathable gas
RPD
This clause supersedes ISO 17420-4:2021, 6.1.
For more information see also the introduction in the other parts of the ISO 17420 series.
vi © ISO 2021 – All rights reserved

INTERNATIONAL STANDARD ISO 17420-5:2021(E)
Respiratory protective devices — Performance
requirements —
Part 5:
Special application fire and rescue services - Supplied
breathable gas RPD and filtering RPD
1 Scope
This document specifies the minimum requirements for supplied breathable gas RPD and filtering RPD
to be used for special application fire and rescue services.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 6529:2013, Protective clothing — Protection against chemicals — Determination of resistance of
protective clothing materials to permeation by liquids and gases
ISO 8031, Rubber and plastics hoses and hose assemblies — Determination of electrical resistance and
conductivity
ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests
ISO 10297, Gas cylinders — Cylinder valves — Specification and type testing
ISO 13506-1, Protective clothing against heat and flame — Part 1: Test method for complete garments —
Measurement of transferred energy using an instrumented manikin
ISO 16900-1:2019, Respiratory protective devices — Methods of test and test equipment — Part 1:
Determination of inward leakage
ISO 16900-2, Respiratory protective devices — Methods of test and test equipment — Part 2: Determination
of breathing resistance
ISO 16900-5, Respiratory protective devices — Methods of test and test equipment — Part 5: Breathing
machine, metabolic simulator, RPD headforms and torso, tools and verification tools
ISO 16900-6, Respiratory protective devices — Methods of test and test equipment — Part 6: Mechanical
resistance/strength of components and connections
ISO 16900-7, Respiratory protective devices — Methods of test and test equipment — Part 7: Practical
performance test methods
ISO 16900-8, Respiratory protective devices — Methods of test and test equipment — Part 8: Measurement
of RPD air flow rates of assisted filtering RPD
ISO 16900-10, Respiratory protective devices — Methods of test and test equipment — Part 10: Resistance
to ignition, flame, radiant heat and heat
ISO 16900-12, Respiratory protective devices — Methods of test and test equipment — Part 12:
Determination of volume-averaged work of breathing and peak respiratory pressures
ISO 16900-14, Respiratory protective devices — Methods of test and test equipment — Part 14:
Measurement of sound pressure level
ISO 16972, Respiratory protective devices — Vocabulary and graphical symbols
ISO/TS 16975-1:2016, Respiratory protective devices — Selection, use and maintenance — Part 1:
Establishing and implementing a respiratory protective device programme
ISO 17420-1:2021, Respiratory protective devices — Performance requirements — Part 1: General
ISO 17420-2:2021, Respiratory protective devices — Performance requirements — Part 2: Requirements
for filtering RPD
ISO 17420-4:2021, Respiratory protective devices — Performance requirements — Part 4: Requirements
for supplied breathable gas RPD
ISO 80079-36:2016, Explosive atmospheres — Part 36: Non-electrical equipment for explosive
atmospheres — Basic method and requirements
IEC 60068-2-27:2010, Environmental testing — Part 2-27: Tests — Test Ea and guidance: Shock
IEC 60068-2-64, Environmental testing — Part 2-64: Tests — Test Fh: Vibration, broadband random and
guidance
IEC 60079-0, Explosive atmospheres — Part 0: Equipment — General requirements
IEC 60529:2013, Degrees of protection provided by enclosures (IP Code)
IEC 60721-1:2002, Classification of environmental conditions — Part 1: Environmental parameters and
their severities
IEC 60721-3-2:2018, Classification of environmental conditions — Part 3-2: Classification of groups of
environmental parameters and their severities — Transportation and Handling
IEC 61000-6-2, Electromagnetic compatibility (EMC) — Part 6-2: Generic standards — Immunity standard
for industrial environments
EN 15333-1:2008, Respiratory equipment - Open-circuit umbilical supplied compressed gas diving
apparatus - Part 1: Demand apparatus
ASTM D1003: 2013, Standard Test Method for Haze and Luminous Transmittance of Transparent Plastics
ASTM D6413, Standard Test Method for Flame Resistance of Textiles (Vertical Test)
NFPA 1981:2019, Standard on Open-Circuit Self-Contained Breathing Apparatus (SCBA) for Emergency
Services
3 Terms, definitions, abbreviations and symbols
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 16972 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 http:// www .electropedia .org/
2 © ISO 2021 – All rights reserved

3.1.1
non pre-conditioned state
without pre-conditioning but possibly modified to carry out tests or already used in non-destructive
tests
Note 1 to entry: This includes e.g., cleaning and disinfection.
3.1.2
RPD in as worn state
RPD where all components are connected and assembled in the way that it is intended to be used (e.g.
worn by the wearer, adapted to an RPD headform or RPD headform and torso or suitable holder)
Note 1 to entry: All of the various components (e.g. for an SCBA: cylinder, respiratory interface, demand valve,
harness etc.) have been completely assembled and then connected (RI connected to the demand valve) together
in accordance with the information supplied by the manufacturer.
3.1.3
component in ready for assembly state
component with seal, plug, packaging or other environmental protective means, still in place
3.1.4
RPD in ready for use state
RPD ready to be donned as described by the manufacturer
Note 1 to entry: In line with the information supplied by the manufacturer for donning the RPD, further actions
can be necessary.
3.2 Abbreviated terms
RI Respiratory Interface
RPD Respiratory protective devices
4 Classification overview
ISO 17420-2:2021, Clause 4 or ISO 17420-4:2021, Clause 4 applies.
4.1 General
ISO 17420-1:2021, 4.1 applies.
4.2 Supplied breathable gas RPD
This subclause applies in addition to ISO 17420-4:2021, Clause 4.
Additionally supplied breathable gas RPD may be classified for one or more special applications, as
given in Table 1.
Table 1 — Special application classification supplied breathable gas RPD
Special application Classes
a
FF5 (Firefighting type R2)
a
FF4 (Firefighting type R1)
Fire and rescue services FF3 (Hazardous material)
FF2 (Rescue)
FF1 (Wildland firefighting)
a
Selection of the RPD shall be based on a risk assessment, which includes compatibility of the selected RPD being
worn with other items of PPE, taking into consideration operational practices, environmental conditions, local building
regulations or standards and other technical standards. See e.g. ISO/TS 16075-1, ISO 17420-1:2021, 5.4 and ISO 11999-2.
FF4 (type R1) and FF5 (type R2) items of RPD have differing performance characteristics.
For example, type R1 provides material thermal performance tested at 180 °C maximum and is commonly used for
defensive firefighting and is generally not intended to be used for internal attack firefighting. Type R2 provides a material
thermal performance tested at 260 °C maximum and is commonly used for internal attack firefighting.
Example for a supplied breathable gas RPD for special application firefighting type R1 with protection
class (PC5), work rate class (W3), RI class (cT), supplied breathable gas capacity class (S1800) and
special application class (FF4)
Marking for the given example PC5 W3 cT S1800 FF4
4.3 Filtering RPD
This subclause applies in addition to ISO 17420-2:2021, Clause 4.
Additionally filtering RPD may be classified for one or more special applications, as given in Table 2.
Table 2 — Special application classification of filtering RPD
Special application Classes
FF2 (Rescue)
Fire and rescue services
FF1 (Wildland firefighting)
Example for a filtering RPD for special application wildland firefighting with protection class (PC3),
work rate class (W2), RI class (bT), particle filter performance class (F3) and special application class
(FF1).
Marking for the given example PC3 W2 bT F3 FF1
Multi-functional filtering RPD have separate classifications for each function, i.e. one classification for
the unassisted mode and one classification for the assisted mode.
5 General requirements for RPD
ISO 17420-1:2021, Clause 5 and ISO 17420-2:2021, Clause 5 or ISO 17420-4:2021, Clause 5 applies.
6 Basic requirements for supplied breathable gas RPD and filtering RPD
All requirements of ISO 17420-2:2021, Clause 6 or ISO 17420-4:2021, Clause 6 apply unless superseded
by this document and indicated in the relevant clauses.
NOTE 1 Optional features are also given in ISO 17420-2 or ISO 17420-4.
NOTE 2 Where requirements are superseded by those in Clause 7 of this document, the test schedules given in
ISO 17420-2:2021 Annex C or ISO 17420-4:2021, Annex C can be used as a guideline for testing.
4 © ISO 2021 – All rights reserved

7 Special application for fire and rescue services filtering and supplied
breathable gas RPD
7.1 Special application for fire and rescue services RPD – Requirement matrices
7.1.1 General
Supplied breathable gas fire and rescue services RPD shall fulfil all requirements specified in Table 3.
Filtering fire and rescue services RPD shall fulfil all requirements specified in Table 4.
7.1.2 Supplied breathable gas fire and rescue services RPD
Table 3 gives an overview about requirements and preconditioning of supplied breathable gas fire and
rescue services RPD.
Table 3 shall be read as follows:
In the first column the requirements are specified. In the third to seventh column the required pre-
conditioning for different fire and rescue services classes are specified.
For each pre-conditioning within one line of the cell different sample(s) shall be used. At least one RPD
shall be tested after each required pre-conditioning.
For the requirement 7.2.1.3 and class hazardous materials (FF3) the following applies.
At least one sample shall be pre-conditioned VS & CE (Exposure to vibration and shock – firefighting
and enhanced resistance to corrosion – constant exposure).
At least one further sample shall be pre-conditioned DR (Exposure to impact from drop).
Table 3 — Special application requirement overview – Supplied breathable gas fire and rescue
services RPD
Wildland Hazardous
Rescue Firefighting
firefighting materials
a a
FF1 FF2 FF3 FF4 FF5
Protection Protection Protection Protection Protection
class class class class class
Requirement Title
≥PC3 ≥PC3 ≥PC4 ≥PC5 ≥PC5
Work rate Work rate Work rate Work rate Work rate
class class class class class
≥W2 ≥W2 ≥W2 ≥W3 =W4
Pre-conditioning
VS&CE VS&CE VS&CE VS&CE VS&CE
Temperature of operation
7.2.1.3
– level 0
DR DR DR DR DR
Temperature of operation
7.2.1.5 AR/NP AR/NP AR/NP AR/NP AR/NP
– level 1
Temperature of operation
b b b b
7.2.1.7 — — — AR/NP —
– level 2- type R1
Temperature of operation
b b b b
7.2.1.8 — — — — AR/NP
– level 3- type R2
Temperature of operation
b b b
7.2.1.9 — — — AR/NP AR/NP
at level 2 and flammability
Temperature of operation
b b b b
7.2.1.10 — — — — AR/NP
at level 3 and flammability
Table 3 (continued)
Wildland Hazardous
Rescue Firefighting
firefighting materials
a a
FF1 FF2 FF3 FF4 FF5
Protection Protection Protection Protection Protection
class class class class class
Requirement Title
≥PC3 ≥PC3 ≥PC4 ≥PC5 ≥PC5
Work rate Work rate Work rate Work rate Work rate
class class class class class
≥W2 ≥W2 ≥W2 ≥W3 =W4
Pre-conditioning
b
7.2.1.11 Thermal shock — AR/NP AR/NP AR/NP AR/NP
Fabric material flame re-
b b
7.2.2.2 AR/NP AR/NP AR/NP — —
sistance performance
7.2.3.2 Radiant heat – level 1 AR/NP AR/NP AR/NP AR/NP AR/NP
b b b
7.2.3.3 Radiant heat – level 2 — — — AR/NP AR/NP
b b b b
7.2.3.4 Radiant heat – level 3 — — — — AR/NP
7.2.4 Resistance to hot particles AR/NP AR/NP AR/NP AR/NP AR/NP
Chemical resistance of
b
7.2.5.1 — AR/NP AR/NP AR/NP AR/NP
materials
b b
7.2.6 Hazardous materials — — AR/NP O O
Contact with hot and cold
7.2.7.1 AR/NP AR/NP AR/NP AR/NP AR/NP
surfaces
Avoidance of frictional
b
7.2.8 — AR/NP AR/NP AR/NP AR/NP
sparks
Visor after chemical expo-
b
7.2.9 — AR/NP AR/NP AR/NP AR/NP
sure
b
7.2.10.1 Connections — AR/NP AR/NP AR/NP AR/NP
Abrasion resistance of
b b
7.2.10.3 — — AR/NP AR/NP AR/NP
visor
Requirements for audible
b b
7.2.11 — — AR/NP AR/NP AR/NP
warning devices
Practical performance -
b
7.2.12 — AR/NP AR/NP AR/NP AR/NP
RPD
7.2.13 Eye irritation (external) AR/NP AR/NP AR/NP AR/NP AR/NP
Operating during submer-
7.2.14 AR/NP AR/NP AR/NP AR/NP AR/NP
sion
Communication perfor-
b b
7.2.16 mance (speaking and — — AR/NP AR/NP AR/NP
hearing)
Use in explosive atmos-
b
7.2.17.1 — AR/NP AR/NP AR/NP AR/NP
pheres
Electromagnetic compat-
b
7.2.17.2 — AR/NP AR/NP AR/NP AR/NP
ibility
b b b c c
7.2.19 Exposure to dust — — — X X
6 © ISO 2021 – All rights reserved

Table 3 (continued)
Wildland Hazardous
Rescue Firefighting
firefighting materials
a a
FF1 FF2 FF3 FF4 FF5
Protection Protection Protection Protection Protection
class class class class class
Requirement Title
≥PC3 ≥PC3 ≥PC4 ≥PC5 ≥PC5
Work rate Work rate Work rate Work rate Work rate
class class class class class
≥W2 ≥W2 ≥W2 ≥W3 =W4
Pre-conditioning
a
Selection of the RPD shall be based on a risk assessment, which includes compatibility of the selected RPD being
worn with other items of PPE, taking into consideration operational practices, environmental conditions, local
building regulations or standards and other technical standards. See e.g. ISO 17420-1:2021, 5.4 and ISO 11999-2.
FF4 (type R1) and FF5 (type R2) items of RPD have differing performance characteristics.
For example, type R1 provides material thermal performance tested at 180 °C maximum and is commonly used for
defensive firefighting and is generally not intended to be used for internal attack firefighting. Type R2 provides a
material thermal performance tested at 260 °C maximum and is commonly used for internal attack firefighting.
b
— means that a test is not required for this combination of requirement and special application class.
c
X means exposure to dust has to be addressed by the FMEA (see 7.2.19).
AR/NP as received or in non pre-conditioned.
VS & CE Exposure to vibration and shock (see 7.3.2) and enhanced resistance to corrosion –constant exposure
(see 7.3.5).
DR Exposure to impact from drop (see 7.3.4).
O Optional feature.
7.1.3 Filtering fire and rescue services RPD
Table 4 gives an overview about requirements and pre-conditioning of filtering fire and rescue services
RPD.
At least one RPD shall be tested after each required pre-conditioning. Pre-conditionings shall not be
combined.
Table 4 shall be read as follows:
In the first column the requirements are specified. In the third and fourth column the required pre-
conditioning for different fire and rescue services classes are specified.
For each pre-conditioning within one cell different sample(s) shall be used.
EXAMPLE For the requirement 7.2.1.4 and class rescue (FF2) the following applies.
At least one sample shall be pre-conditioned VS (Exposure to vibration and shock – fire and rescue
services).
Table 4 — Special application requirement overview – Filtering RPD – Fire and rescue services
Wildland Fire-
Rescue
fighting
FF1 FF2
Protection class Protection class
Requirement Title
≥PC3 ≥PC3
Work rate class Work rate class
≥W2 ≥W2
DRO DRO
ISO 17420-2:2021,
Particle filter
6.10.1.2
EA EA
DRO DRO
ISO 17420-2:2021,
a
Gas filter
6.10.1.3
EA EA
7.2.1.4 Temperature of operation – level 0 VS VS
a
7.2.1.6 Temperature of operation – level 1 AR/NP AR/NP
b
7.2.8 Avoidance of frictional sparks — AR/NP
a b
7.2.2.1 Six burner dynamic AR/NP —
a
7.2.3.2 Radiant heat – level 1 AR/NP AR/NP
a
7.2.4 Resistance to hot particles (embers, sparks, ash) AR/NP AR/NP
7.2.5.2 Chemical resistance of materials — AR/NP
7.2.7.2 Contact with hot surfaces generated by the RPD AR/NP AR/NP
b
7.2.10.2 Connections — AR/NP
7.2.10.3 Abrasion resistance of visor AR/NP AR/NP
7.2.17.1 Use in explosive atmospheres AR/NP AR/NP
7.2.17.2 Electromagnetic compatibility AR/NP AR/NP
7.2.13 Eye irritation (external) AR/NP AR/NP
b b
7.2.16 Communication performance (speaking and hearing) — —
7.2.15 Resistance to water splash AR/NP AR/NP
Filter capacity and filter performance for the test
b
7.2.18.2.1 AR/NP —
a
gas CO
Filter capacity for the test gases other than CO and
7.2.18.2.2 AR/NP AR/NP
a
particle filter efficiency
c c
7.2.19 Exposure to dust X X
a
If claimed for FF 1 (wildland firefighting).
b
— means that a test is not required for this combination of requirement and special application class.
c
X means exposure to dust has to be addressed by the FMEA (see 7.2.19).
AR/NP as received or in non pre-conditioned state.
DRO Exposure to impact from drop (see 7.3.3).
VS Exposure to vibration and shock (see 7.3.2).
EA Exposure to exhaled air, if applicable (see ISO 17420-2:2021 6.9.3.1).
8 © ISO 2021 – All rights reserved

7.2 Requirements for special application fire and rescue services RPD
7.2.1 Thermal Requirements
7.2.1.1 Temperature of operation – Supplied breathable gas RPD
After exposure to the relevant temperature levels outlined in 7.2.1.3, 7.2.1.5, 7.2.1.7, 7.2.1.8, 7.2.1.9,
7.2.1.10 and 7.2.1.11 warning and monitoring devices, if applicable, shall continue to function.
The preheating shall be homogenous around the RPD.
Deformation or superficial damage of components does not constitute a failure.
Check in accordance with 8.2.
7.2.1.2 Temperature of operation – Filtering RPD
After exposure to the relevant temperature levels outlined in 7.2.1.4 and 7.2.1.6, warning and monitoring
devices, if applicable, shall continue to function.
Deformation or superficial damage of components does not constitute a failure.
Check in accordance with 8.2.
7.2.1.3 Temperature of operation – level 0 – Supplied breathable gas RPD
This clause supersedes clause ISO 17420-4:2021, 6.1.
RPD in ready for use state or the RPD component in ready for assembly state shall be exposed to the
pre-conditioning in accordance with 7.3.2 and 7.3.5 and the relevant subclauses as given in Table 3.
+2
 
One RPD shall be equilibrated for a minimum of 4 h and tested at −32 °C.
 
 
 
One RPD shall be equilibrated for a minimum of 4 h and tested at 60 °C.
 
−2
 
The RPD shall continue to meet the work of breathing/breathing resistance requirements at the work
rate regime for the RPD class, as specified in ISO 17420-4:2021, 6.2.
Testing shall be performed in accordance with ISO 16900-12.
For RPD having cylinder valve(s), the valve(s) shall meet the requirements of ISO 10297 at the
+2
 
temperature of operation of −32 °C and an impact of 120 J.
 
 
7.2.1.4 Temperature of operation – level 0 – Assisted filtering RPD
The influence of temperature of flow rate shall be determined in accordance with ISO 17420-2:2021, 6.2
+2 0
   
but using the temperatures of −32 °C and 60 °C.
   
0 −2
   
RPD shall continue to meet the work of breathing/breathing resistance requirements at the test regime
for the RPD work rate class, as specified in ISO 17420-2:2021, 6.3.1 or 6.3.2.
Testing shall be performed in accordance with ISO 16900-12.
7.2.1.5 Temperature of operation – level 1 – Supplied breathable gas RPD
 
One RPD in as worn state shall be exposed to 100 °C whilst the RPD is ventilated with the settings
 
−2
 
of the test equipment at 35 l/min for 30 min or the service life of the RPD, whatever is shorter. Testing
shall be started 2 min before the end of the exposure time or service life. The RPD shall continue to
meet the work of breathing/breathing resistance requirements at 35 l/min setting of the test equipment,
as specified in ISO 17420-4:2021, 6.2.
Testing shall be performed in accordance with ISO 16900-12.
7.2.1.6 Temperature of operation – level 1 – Assisted filtering RPD
To determine the influence of temperature the RPD shall be tested for flow after each of the following:
 
One RPD in as worn state shall be exposed to 100 °C for 30 min. Testing shall be started within
 
−2
 
3 min after the exposure at ambient laboratory temperature.
Taking into account the influencing parameters as specified in ISO 17420-2:2021, 6.1, the measured
minimum and the measured maximum flow rate shall be determined in accordance with ISO 16900-8.
The RPD shall continue to meet the work of breathing/breathing resistance requirements as specified
in ISO 17420-2:2021, 6.3.2.
Testing shall be performed in accordance with and ISO 16900-12.
7.2.1.7 Temperature of operation – level 2- FF4 (type R1) – Supplied breathable gas RPD
One RPD in as worn state shall be tested as received at (180 ± 5) °C for 5 min.
Testing shall be performed as part of 7.2.1.9.
7.2.1.8 Temperature of operation – level 3-FF5 (type R2) – Supplied breathable gas RPD
One RPD in as worn state shall be tested as received at ()260±5 °C for 5 min.
Testing shall be performed as part of 7.2.1.10.
7.2.1.9 Temperature of operation – level 2 and flammability – Supplied breathable gas RPD
Temperature of operation level 3 is specified by a flame engulfment test after pre-conditioning at
180±5 °C .
()
One RPD, as received and in as worn state shall be subjected to (950 ± 50) °C for 10 s at 105 l/min
(42 cycles/min and 2,5 l/cycle) after the temperature exposure of (180 ± 5) °C for 5 min at a ventilation
rate of 40 l/min (20 cycles/min and 2 l/cycle) in accordance with the flame engulfment test specified in
ISO 16900-10.
The change of the ventilation rate from 40 l/min to 105 l/min shall be completed prior to the start of
the flame exposure. The transition period between one flow rate and the next flow rate shall be no
more than 60 s whilst the RPD remains in the operational mode.
No after-flame shall continue for more than 2,2 s after the test flame extinguishes.
Additionally, no component that secures the apparatus to the user’s body or that secures the cylinder
to the apparatus shall separate or be displaced to such an extent that would cause the RPD to become
detached from the wearer’s body or the cylinder to become unsecured.
10 © ISO 2021 – All rights reserved

Check in accordance with 8.2.
The breathing resistance shall not exceed 1 200 Pa at both flow rates.
Testing shall be performed in accordance with ISO 16900-10.
7.2.1.10 Temperature of operation – level 3 and flammability – Supplied breathable gas RPD
Temperature of operation level 4 is specified by a flame engulfment test after pre-conditioning at
(260 ± 5) °C.
One RPD, as received and in as worn state shall be subjected to (950 ± 50) °C for 10 s at 105 l/min after
the temperature exposure of (260 ± 5) °C for 5 min at a ventilation rate of 40 l/min (20 l/min × 2) in
accordance with the flame engulfment test ISO 16900-10.
The change of the ventilation rate from 40 l/min to 105 l/min shall be completed prior to the start of
the flame exposure. The transition period between one flow rate and the next flow rate shall be no
more than 60 s whilst the RPD remains in the operational mode.
Additionally, no component that secures the apparatus to the user’s body or that secures the cylinder
to the apparatus shall separate or be displaced to such an extent that would cause the RPD to become
detached from the wearer’s body or the cylinder to become unsecured.
Check in accordance with 8.2.
The breathing resistance shall not exceed 1 200 Pa at both flow rates.
Testing shall be performed in accordance with ISO 16900-10.
7.2.1.11 Thermal shock – Supplied breathable gas RPD
+2
 
One RPD in ready for use state shall be equilibrated for a minimum of 4 h at −32 °C and tested
 
 
within 10 min at (60 ± 5) °C.
 
One RPD in ready for use state shall be equilibrated for a minimum of 4 h at 60 °C and tested
 
−2
 
within 10 min at (-32 ± 5) °C.
The RPD shall continue to meet the work of breathing/breathing resistance requirements specified in
ISO 17420-4:2021, 6.3 at the work rate regime for the RPD class, as specified in ISO 17420-4:2021, 6.2.
7.2.2 Resistance to flame
7.2.2.1 Six burner dynamic – Filtering RPD
This clause supersedes ISO 17420-1:2021, 5.3 for the RI only.
One RI as received shall be tested for flame and heat resistance as specified in ISO 16900-10. Prior to
testing, all components and accessories, which are claimed by the manufacturer as part of the RPD,
shall be assembled with the RI. The components and accessories shall be in as received state. There
shall be no dripping at all, and the assembly under test shall not continue to burn for more than 5 s.
Deformation/decomposition is allowed, as long as it does not drip or burn through or present any other
hazard to the wearer.
The tip of each burner shall be set at 250 mm from the closest point upon which that flame will impinge,
following the contour of the RI and component contour.
The RPD or the RI does not need to fulfil any other requirement of this standard after this test.
Check in accordance with 8.2.
After exposure to flame the RPD or RI shall not leak at a rate of more than one bubble per second.
Testing shall be performed in accordance with 8.3.
7.2.2.2 Fabric material flame resistance performance – Supplied breathable gas RPD
This clause supersedes ISO 17420-1:2021, 5.3 for fabric materials only.
Three test samples shall be conditioned by five cycles of washing and drying in accordance with the
procedures specified in the information supplied by the RPD manufacturer.
If washing is not intended in accordance with the information supplied by the RPD manufacturer, three
samples shall be tested as received.
All fabric material of RPD used to secure the RPD to the wearer shall be tested as designed for its
function for flame resistance as specified in ISO 16900-10, in accordance with ASTM D6413 and shall
not
— exceed an average char length of 100 mm,
— exceed an after flame time of 2,0 s,
— drip.
7.2.3 Radiant heat
7.2.3.1 General
One RPD shall be tested as received in as worn state for resistance to radiant heat specified in 7.2.3.2,
7.2.3.3 or 7.2.3.4. When exposed to the relevant conditions given in 7.2.3.2 or 7.2.3.3, while ventilated
and subsequently returned to ambient conditions, no component of the RPD shall melt through or burn
through as checked in accordance with ISO 17420-1:2021, 6.2 and the RPD shall continue to meet the
breathing resistance requirements specified in ISO 17420-2:2021, 6.2.
Deformation of components does not constitute a failure.
For levels 1 and 2 exposures, one RPD shall be tested on a head and torso with a radiant heat panel in
the front and, after the RPD has cooled down to ambient temperature, from the back.
The donning of the RPD shall be performed in accordance with the information supplied by the
manufacturer. If more than one position is possible chose that which exposes functional parts to the
heat flux the most.
Heat-Flux shall be measured at the point of the RPD closest to the radiant heat panel.
Level 3 exposure is assessed in the instrumented manikin test, in accordance with ISO 13506-1 and
ISO 16900-10.
Test in accordance with ISO 13506-1 and ISO 16900-10.
7.2.3.2 Radiant heat – level 1 – Supplied breathable gas RPD and filtering RPD
One RPD shall be exposed to a radiant heat of 1,25 kW/m for 30 min at the flow rate of 35 l/min
(dynamic sinusoidal) and the setting of the test equipment in accordance with ISO 17420-4:2021 Table 2
and following the requirements given in 7.2.3.
12 © ISO 2021 – All rights reserved

Breathing resistance (peak pressure) shall be measured during the exposure. The breathing resistance
(peak pressure) shall not exceed 1 200 Pa. For supplied breathable gas RPD and assisted filtering RPD
with work rate class ≥3 the inhalation breathing resistance (peak pressure) shall be greater than
...