ISO 20854:2019
(Main)Thermal containers — Safety standard for refrigerating systems using flammable refrigerants — Requirements for design and operation
Thermal containers — Safety standard for refrigerating systems using flammable refrigerants — Requirements for design and operation
This document describes the design of the mechanical refrigeration unit (MRU) and operation of container refrigerating systems in all anticipated operational modes and locations. It describes the industry's best practices for the safe operation of flammable refrigerants in refrigerating systems used in thermal freight containers operated on board ships, in terminals, on road, on rail and on land. This document addresses the use of flammable refrigerants with classifications defined in ISO 817, defined as 2L, 2 and 3, except R717 (Ammonia). This document describes an operational mode risk assessment (OMRA) which uses methods such as HAZOP (Hazard and operability analysis), FMEA (Failure mode and effects analysis), or FTA (Fault tree analysis) or combination of methods. This document specifies requirements for the validation and consideration of possible safety concepts and protective devices within the OMRA process, including charge release tests, simulation, and function tests of the associated protective equipment. It defines test requirements for shock, impact, and vibration. A validation procedure is given to demonstrate that risks from hazardous events are investigated and their severity and frequency are meaningfully reduced, with the aim of achieving tolerable risk values. The obligations of the manufacturer, the container owner as well as the responsible operator are described, as well as how stakeholders can investigate and mitigate risks associated with the use of flammable refrigerants. Finally, this document describes the requirements of service and maintenance when working with flammable refrigerants. This document is restricted to refrigerating systems integrated with or mounted on ISO thermal containers according to ISO 1496-2. It provides minimum requirements for reducing the risk associated with the use of flammable refrigerants. The scope is limited to container refrigerating systems operated in conjunction with the carriage of refrigerated cargo as operating reefer (OR) or when used as a non-operating reefer (NOR) or when empty for positioning — while in intermodal transit. Static land-based continuous operations are excluded.
Conteneurs thermiques — Norme de sécurité pour les systèmes réfrigérants utilisant des fluides frigorigènes inflammables — Exigences de conception et de fonctionnement
General Information
Buy Standard
Standards Content (Sample)
ISO 20854:2019(E)
Deleted: /FDIS
Deleted: /FDIS
ISO 20854:2019(E)
ISO TC 104/SC 2 N496
Thermal containers — Safety standard for refrigerating systems using flammable
refrigerants – Requirements for design and operation
© ISO 2019 – All rights reserved i
---------------------- Page: 1 ----------------------
ISO 20854:2019(E)
Deleted: /FDIS
© ISO 2019, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or
utilised 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
Ch. de Blandonnet 8 • CP 401
CH‐1214 Vernier, Geneva, Switzerland
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2019 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 20854:2019(E)
Deleted: /FDIS
Contents
Foreword . 6
Introduction. 7
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols and abbreviated terms . 11
5 Safety requirements for the design of container refrigerating systems . 11
5.1 General . 11
5.2 Significant hazards of the refrigerating system . 11
5.3 Safety concept for container refrigerating systems . 12
5.3.1 General . 12
5.3.2 Operational mode risk assessment . 12
5.3.3 Tolerable risk . 14
5.3.4 Flammable refrigerants . 16
5.3.5 Protection against hazards . 17
5.3.6 Validation of safety concept and protective devices . 17
gn and construction of the refrigerating system . 18
6 Desi
6.1 General . 18
6.2 Components and piping of refrigerating systems with flammable refrigerant . 18
6.2.1 General . 18
6.2.2 Components . 18
6.2.3 External fire relief device . 18
6.3 Assemblies . 19
6.3.1 General . 19
6.3.2 Components and joints . 19
6.4 Interior of the thermal container . 19
6.4.1 General . 19
6.4.2 Ventilation inside the container . 19
6.4.3 Refrigerant detectors . 20
6.4.4 Protection against hot surfaces . 20
6.4.5 Electrical components . 20
6.5 Outside electrical cabinet . 20
6.6 Refrigerant charge . 21
stem . 21
6.7 Alarm sy
6.7.1 General . 21
6.7.2 Alarm system power . 21
6.8 Testing . 22
6.8.1 General . 22
6.8.2 Protective device test . 22
6.8.3 Vibration type-test . 22
6.8.4 Shock and impact type test . 22
6.8.5 Production test . 23
6.9 Marking and documentation . 23
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ISO 20854:2019(E)
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6.9.1 General . 23
6.9.2 Marking . 23
6.9.3 Manuals and documentation . 24
6.10 Certification . 25
7 Design related requirements of the MRU manufacturer for safe service, maintenance,
repair . 26
7.1 Education and training . 26
7.2 Safety instructions . 26
7.3 Testing before operation . 27
7.4 Maintenance and repair . 27
8 General recommendations at operating sites . 28
9 Safe operation at different operating sites . 29
9.1 General . 29
9.2 Operating sites . 30
9.3 Significant hazards . 31
9.4 Ventilating condition at operating sites . 32
9.4.1 Requirements for operation in open air . 32
9.4.2 Requirements for operation in well-ventilated areas . 32
9.4.3 Requirements for operation in non-well-ventilated areas . 33
9.4.4 Container operation in non-ventilated areas . 34
9.5 Requirements for opening of container door and for packing and un-packing of
goods . 34
9.6 Electrical installations at operating sites . 35
9.7 Operator instruction for handling of alarms . 35
9.8 Accidents . 36
9.8.1 Measures for accidents prevention. 36
9.8.2 Measures after accidents . 37
9.9 Operating instructions, manuals, guidelines at operating sites . 38
9.10 Information in the manual related to operating sites. 38
10 Servicing recommendations and requirements at operating sites . 38
10.1 Operating sites with service activities . 39
10.2 General . 39
10.2.1 Instruction of personnel . 39
10.2.2 General failure prevention . 40
10.3 Repair and maintenance on the container structure . 40
10.4 Repair and maintenance on the MRU including opening of the refrigerating system . 40
10.4.1 General . 40
10.4.2 Instruction of personnel . 40
10.4.3 Work area requirements . 41
10.4.4 Inspection . 41
10.4.5 System failures . 42
10.4.6 Actions and procedure for repair and opening of the refrigerating system . 42
10.4.7 Tools and equipment . 45
10.4.8 Testing after repair . 46
10.4.9 Failure prevention for repair and opening of the refrigerating system . 46
10.4.10 Documentation . 46
10.5 Handling, recovery, reuse and disposal of refrigerant . 46
11 Decommissioning of the container refrigerating system . 47
Annex A (informative) Definition of control volumes . 48
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ISO 20854:2019(E)
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Annex B (informative) Description of mechanisms to reduce risk . 49
B.1 General . 49
B.2 Separation mechanism . 49
B.3 Ventilation mechanism . 50
B.3.1 General . 50
B.3.2 Outside ventilation mechanism . 50
B.3.3 Inside ventilation mechanism . 50
B.4 Refrigerant detection . 51
B.5 Alarm system . 51
B.5.1 Types of alarm . 51
B.5.2 Visible and audible refrigerant leak alarm . 52
B.5.3 Actions by the alarm system . 53
B.6 Shut-off devices . 53
B.7 Examples of alternative systems . 53
Annex C (normative) Information on leak types and leak mass flow . 57
Annex D (normative) Useful equations for the calculation of ventilation environment . 59
D.1 General . 59
D.2 Dilution of a flammable substance release with air . 59
D.3 Additional examples . 61
D.3.1 Small volume in open air situation . 61
volume in a well-ventilated area . 61
D.3.2 A small
D.3.3 A non-well-ventilated area . 62
D.3.4 A Non-ventilated enclosure . 63
Bibliography . 64
© ISO 2019 – All rights reserved v
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ISO 20854:2019(E)
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Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national
standards bodies (ISO member bodies). The work of preparing International Standards is normally
carried out through ISO technical committees. Each member body interested in a subject for which a
technical committee has been established has the right to be represented on that committee.
International organizations, governmental and non‐governmental, in liaison with ISO, also take part in
the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all
matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT)
see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 104, Freight containers, SC 2, Specific
purpose containers.
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 2019 – All rights reserved
---------------------- Page: 6 ----------------------
ISO 20854:2019(E)
Deleted: /FDIS
Introduction
This document has been developed to enable the use of flammable refrigerants in refrigerated thermal
containers. This document enables container owners and operators to understand and validate the
risks associated with operating refrigerating equipment using previously non‐acceptable flammable
refrigerants. The goal is to achieve an acceptable level of safety for container refrigerating systems
using flammable refrigerants as for container refrigerating systems using non‐flammable refrigerants.
The background for initiating the development of this document was the foreseeable impact of global
and national regulations on hydrofluorocarbons (HFCs) currently used in thermal containers.
Hydrofluorocarbons are listed in the Kigali Amendment to the Montreal Protocol from 2016 due to the
high global warming potential (GWP) of HFCs and a phase down in the use and availability of R134a,
R404A and, for low temperature, R23, is expected in intermodal transport refrigeration.
This document is intended to complement ISO 1496‐2 but not to replace existing standards such as the
ISO 5149 series. It provides minimum requirements for the design of a refrigerating system and follows Deleted: it
a risk‐based approach to reduce, but not eliminate, the risks to persons, assets and the environment.
The working group, which developed this document consisted of representatives from refrigerating
system manufacturers, refrigerated container box manufacturers, shipping lines, classification societies,
equipment owners and other interested industry experts.
© ISO 2019 – All rights reserved vii
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ISO 20854:2019(E)
Deleted: /FDIS
Thermal containers — Safety standard for refrigerating systems
using flammable refrigerants – Requirements for design and
operation
1 Scope
This document describes the design of the mechanical refrigeration unit (MRU) and operation of
container refrigerating systems in all anticipated operational modes and locations.
It describes the industry's best practices for the safe operation of flammable refrigerants in
refrigerating systems used in thermal freight containers operated on board ships, in terminals, on road,
on rail and on land.
This document addresses the use of flammable refrigerants with classifications defined in ISO 817,
defined as 2L, 2 and 3, except R717 (Ammonia).
This document describes an operational mode risk assessment (OMRA) which uses methods such as
HAZOP (Hazard and operability analysis), FMEA (Failure mode and effects analysis), or FTA (Fault tree
analysis) or combination of methods.
This document specifies requirements for the validation and consideration of possible safety concepts
and protective devices within the OMRA process, including charge release tests, simulation, and
function tests of the associated protective equipment. It defines test requirements for shock, impact,
and vibration. A validation procedure is given to demonstrate that risks from hazardous events are
investigated and their severity and frequency are meaningfully reduced, with the aim of achieving
tolerable risk values.
The obligations of the manufacturer, the container owner as well as the responsible operator are
described, as well as how stakeholders can investigate and mitigate risks associated with the use of
flammable refrigerants.
Finally, this document describes the requirements of service and maintenance when working with
flammable refrigerants.
This document is restricted to refrigerating systems integrated with or mounted on ISO thermal
containers according to ISO 1496‐2. It provides minimum requirements for reducing the risk associated
with the use of flammable refrigerants.
The scope is limited to container refrigerating systems operated in conjunction with the carriage of
refrigerated cargo as operating reefer (OR) or when used as a non‐operating reefer (NOR) or when
empty for positioning — while in intermodal transit. Static land‐based continuous operations are
excluded.
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 817, Refrigerants — Designation system
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ISO 20854:2019(E)
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ISO 1496‐2, Freight containers — Specification and testing — Thermal containers
ISO 5149 (all parts), Refrigerating systems and heat pumps — Safety and environmental requirements
ISO 14903, Refrigerating systems and heat pumps — Qualification of tightness of components and joints
IEC 60068‐2‐6, Environmental testing — Part 2-6: Tests — Test Fc: Vibration (sinusoidal)
IEC 60068‐2‐75, Environmental testing — Part 2-75: Tests — Test Eh: Hammer tests
IEC 60079‐10‐1, Explosive atmospheres — Part 10-1: Classification of areas — Explosive gas atmospheres
IEC 60079‐14, Explosive atmospheres — Part 14: Electrical installations, design, selection and erection
IEC 60079‐15, Explosive atmospheres — Part 15: Equipment protection by type of equipment “n”
IEC 60335‐2‐40, Household and similar electrical appliances — Safety — Part 2-40: Particular
requirements for electrical heat pump, air-conditioners and dehumidifiers
EN 1127‐1, Explosive atmospheres — Explosion prevention and protection — Part 1: Basic concepts and
methodology
EN 14624, Performance of portable leak detectors and of room monitors for halogenated refrigerants
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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/
3.1
alarm system
system constituting all electrical and electronic parts of the refrigerating system which monitor the
correct function of the protective device(s) and/or give a warning in case of malfunctioning or
refrigerant leakage
3.2
hazardous area
area in which a flammable or toxic atmosphere is present, or may be expected to be present, in
quantities such as to require special precautions for construction, installation or use of apparatus
[SOURCE: IEC‐60079‐10‐1:2015, 3.3.1, modified — In the definition, the word "explosive" has been
replaced with "flammable and toxic".]
3.2.1
non-hazardous area
area in which a flammable or toxic atmosphere is not expected to be present in quantities such as to
require special precautions for construction, installation and use of equipment
2 © ISO 2019 – All rights reserved
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ISO 20854:2019(E)
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[SOURCE: IEC‐60079‐10‐1:2015, 3.3.2, modified — In the definition, the word "explosive" has been
replaced with "flammable and toxic".]
3.2.2
temporary hazardous area
area which can be defined as a hazardous area for a short period of time as a consequence of an
abnormal or accidental type leak
3.3
authorized service facility
service facility that is authorized by the manufacturer to repair and to maintain the container
refrigerating system
3.4
condenser section
space of the container where all outside parts of the refrigeration circuit including condenser fan are
located
Note 1 to entry: The condenser section is not a confined space.
Note 2 to entry: The condenser section corresponds to control volume II (see Annex A).
3.5
container refrigerating system
mechanically refrigerated container with a vapour compression refrigeration cycle using refrigerant as
a working fluid
3.6
control volume
theoretical volume representing the space in which a flammable atmosphere can occur as a
consequence of a refrigerant leak
Note 1 to entry: It can be delimited by the internal or external space of a container, and/or by specific component
compartments.
Note 2 to entry: A description of control volumes is included in Annex A.
3.7
durably technically tight
sealed equipment
...
INTERNATIONAL ISO
STANDARD 20854
First edition
2019-10
Thermal containers — Safety
standard for refrigerating systems
using flammable refrigerants
— Requirements for design and
operation
Conteneurs thermiques — Norme de sécurité pour les systèmes
réfrigérants utilisant des fluides frigorigènes inflammables —
Exigences de conception et de fonctionnement
Reference number
ISO 20854:2019(E)
©
ISO 2019
---------------------- Page: 1 ----------------------
ISO 20854:2019(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2019
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
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 20854:2019(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols and abbreviated terms . 9
5 Safety requirements for the design of container refrigerating systems .9
5.1 General . 9
5.2 Significant hazards of the refrigerating system . 9
5.3 Safety concept for container refrigerating systems .10
5.3.1 General.10
5.3.2 Operational mode risk assessment .10
5.3.3 Tolerable risk .12
5.3.4 Flammable refrigerants .13
5.3.5 Protection against hazards .14
5.3.6 Validation of safety concept and protective devices .15
6 Design and construction of the refrigerating system .15
6.1 General .15
6.2 Components and piping of refrigerating systems with flammable refrigerant .16
6.2.1 General.16
6.2.2 Components .16
6.2.3 External fire relief device .16
6.3 Assemblies .16
6.3.1 General.16
6.3.2 Components and joints . .17
6.4 Interior of the thermal container .17
6.4.1 General.17
6.4.2 Ventilation inside the container .17
6.4.3 Refrigerant detectors .17
6.4.4 Protection against hot surfaces .17
6.4.5 Electrical components . .18
6.5 Outside electrical cabinet .18
6.6 Refrigerant charge .18
6.7 Alarm system .19
6.7.1 General.19
6.7.2 Alarm system power .19
6.8 Testing .19
6.8.1 General.19
6.8.2 Protective device test .19
6.8.3 Vibration type-test .20
6.8.4 Shock and impact type test .20
6.8.5 Production test .20
6.9 Marking and documentation .21
6.9.1 General.21
6.9.2 Marking .21
6.9.3 Manuals and documentation .22
6.10 Certification .23
7 Design related requirements of the MRU manufacturer for safe service,
maintenance, repair .23
7.1 Education and training .24
7.2 Safety instructions .24
7.3 Testing before operation .24
© ISO 2019 – All rights reserved iii
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ISO 20854:2019(E)
7.4 Maintenance and repair .24
8 General recommendations at operating sites .25
9 Safe operation at different operating sites .26
9.1 General .26
9.2 Operating sites .27
9.3 Significant hazards .28
9.4 Ventilating condition at operating sites .29
9.4.1 Requirements for operation in open air .29
9.4.2 Requirements for operation in well-ventilated areas .29
9.4.3 Requirements for operation in non-well-ventilated areas .30
9.4.4 Container operation in non-ventilated areas .31
9.5 Requirements for opening of container door and for packing and un-packing of goods .31
9.6 Electrical installations at operating sites .32
9.7 Operator instruction for handling of alarms .32
9.8 Accidents .33
9.8.1 Measures for accidents prevention .33
9.8.2 Measures after accidents .34
9.9 Operating instructions, manuals, guidelines at operating sites .34
9.10 Information in the manual related to operating sites .34
10 Servicing recommendations and requirements at operating sites .35
10.1 Operating sites with service activities .35
10.2 General .35
10.2.1 Instruction of personnel .36
10.2.2 General failure prevention .36
10.3 Repair and maintenance on the container structure .36
10.4 Repair and maintenance on the MRU including opening of the refrigerating system .37
10.4.1 General.37
10.4.2 Instruction of personnel .37
10.4.3 Work area requirements .38
10.4.4 Inspection .38
10.4.5 System failures .38
10.4.6 Actions and procedure for repair and opening of the refrigerating system .39
10.4.7 Tools and equipment .41
10.4.8 Testing after repair .42
10.4.9 Failure prevention for repair and opening of the refrigerating system .42
10.4.10 Documentation .42
10.5 Handling, recovery, reuse and disposal of refrigerant .43
11 Decommissioning of the container refrigerating system .43
Annex A (informative) Definition of control volumes .44
Annex B (informative) Description of mechanisms to reduce risk .45
Annex C (normative) Information on leak types and leak mass flow .53
Annex D (normative) Useful equations for the calculation of ventilation environment .54
Bibliography .59
iv © ISO 2019 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 20854:2019(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso
.org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 104, Freight containers, SC 2, Specific
purpose containers.
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.
© ISO 2019 – All rights reserved v
---------------------- Page: 5 ----------------------
ISO 20854:2019(E)
Introduction
This document has been developed to enable the use of flammable refrigerants in refrigerated thermal
containers. This document enables container owners and operators to understand and validate the
risks associated with operating refrigerating equipment using previously non-acceptable flammable
refrigerants. The goal is to achieve an acceptable level of safety for container refrigerating systems
using flammable refrigerants as for container refrigerating systems using non-flammable refrigerants.
The background for initiating the development of this document was the foreseeable impact of
global and national regulations on hydrofluorocarbons (HFCs) currently used in thermal containers.
Hydrofluorocarbons are listed in the Kigali Amendment to the Montreal Protocol from 2016 due to the
high global warming potential (GWP) of HFCs and a phase down in the use and availability of R134a,
R404A and, for low temperature, R23, is expected in intermodal transport refrigeration.
This document is intended to complement ISO 1496-2 but not to replace existing standards such as the
ISO 5149 series. It provides minimum requirements for the design of a refrigerating system and follows
a risk-based approach to reduce, but not eliminate, the risks to persons, assets and the environment.
The working group, which developed this document consisted of representatives from refrigerating
system manufacturers, refrigerated container box manufacturers, shipping lines, classification
societies, equipment owners and other interested industry experts.
vi © ISO 2019 – All rights reserved
---------------------- Page: 6 ----------------------
INTERNATIONAL STANDARD ISO 20854:2019(E)
Thermal containers — Safety standard for refrigerating
systems using flammable refrigerants — Requirements for
design and operation
1 Scope
This document describes the design of the mechanical refrigeration unit (MRU) and operation of
container refrigerating systems in all anticipated operational modes and locations.
It describes the industry's best practices for the safe operation of flammable refrigerants in refrigerating
systems used in thermal freight containers operated on board ships, in terminals, on road, on rail and
on land.
This document addresses the use of flammable refrigerants with classifications defined in ISO 817,
defined as 2L, 2 and 3, except R717 (Ammonia).
This document describes an operational mode risk assessment (OMRA) which uses methods such as
HAZOP (Hazard and operability analysis), FMEA (Failure mode and effects analysis), or FTA (Fault tree
analysis) or combination of methods.
This document specifies requirements for the validation and consideration of possible safety concepts
and protective devices within the OMRA process, including charge release tests, simulation, and
function tests of the associated protective equipment. It defines test requirements for shock, impact,
and vibration. A validation procedure is given to demonstrate that risks from hazardous events are
investigated and their severity and frequency are meaningfully reduced, with the aim of achieving
tolerable risk values.
The obligations of the manufacturer, the container owner as well as the responsible operator are
described, as well as how stakeholders can investigate and mitigate risks associated with the use of
flammable refrigerants.
Finally, this document describes the requirements of service and maintenance when working with
flammable refrigerants.
This document is restricted to refrigerating systems integrated with or mounted on ISO thermal
containers according to ISO 1496-2. It provides minimum requirements for reducing the risk associated
with the use of flammable refrigerants.
The scope is limited to container refrigerating systems operated in conjunction with the carriage of
refrigerated cargo as operating reefer (OR) or when used as a non-operating reefer (NOR) or when
empty for positioning — while in intermodal transit. Static land-based continuous operations are
excluded.
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 817, Refrigerants — Designation system
ISO 1496-2, Freight containers — Specification and testing — Thermal containers
ISO 5149 (all parts), Refrigerating systems and heat pumps — Safety and environmental requirements
© ISO 2019 – All rights reserved 1
---------------------- Page: 7 ----------------------
ISO 20854:2019(E)
ISO 14903, Refrigerating systems and heat pumps — Qualification of tightness of components and joints
IEC 60068-2-6, Environmental testing — Part 2-6: Tests — Test Fc: Vibration (sinusoidal)
IEC 60068-2-75, Environmental testing — Part 2-75: Tests — Test Eh: Hammer tests
IEC 60079-10-1, Explosive atmospheres — Part 10-1: Classification of areas — Explosive gas atmospheres
IEC 60079-14, Explosive atmospheres — Part 14: Electrical installations, design, selection and erection
IEC 60079-15, Explosive atmospheres — Part 15: Equipment protection by type of equipment “n”
IEC 60335-2-40, Household and similar electrical appliances — Safety — Part 2-40: Particular requirements
for electrical heat pump, air-conditioners and dehumidifiers
EN 1127-1, Explosive atmospheres — Explosion prevention and protection — Part 1: Basic concepts and
methodology
EN 14624, Performance of portable leak detectors and of room monitors for halogenated refrigerants
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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/
3.1
alarm system
system constituting all electrical and electronic parts of the refrigerating system which monitor
the correct function of the protective device(s) and/or give a warning in case of malfunctioning or
refrigerant leakage
3.2
hazardous area
area in which a flammable or toxic atmosphere is present, or may be expected to be present, in
quantities such as to require special precautions for construction, installation or use of apparatus
[SOURCE: IEC -60079 -10 -1: 2015, 3.3.1, modified — In the definition, the word "explosive" has been
replaced with "flammable and toxic".]
3.2.1
non-hazardous area
area in which a flammable or toxic atmosphere is not expected to be present in quantities such as to
require special precautions for construction, installation and use of equipment
[SOURCE: IEC -60079 -10 -1: 2015, 3.3.2, modified — In the definition, the word "explosive" has been
replaced with "flammable and toxic".]
3.2.2
temporary hazardous area
area which can be defined as a hazardous area for a short period of time as a consequence of an
abnormal or accidental type leak
3.3
authorized service facility
service facility that is authorized by the manufacturer to repair and to maintain the container
refrigerating system
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ISO 20854:2019(E)
3.4
condenser section
space of the container where all outside parts of the refrigeration circuit including condenser fan
are located
Note 1 to entry: The condenser section is not a confined space.
Note 2 to entry: The condenser section corresponds to control volume II (see Annex A).
3.5
container refrigerating system
mechanically refrigerated container with a vapour compression refrigeration cycle using refrigerant as
a working fluid
3.6
control volume
theoretical volume representing the space in which a flammable atmosphere can occur as a consequence
of a refrigerant leak
Note 1 to entry: It can be delimited by the internal or external space of a container, and/or by specific component
compartments.
Note 2 to entry: A description of control volumes is included in Annex A.
3.7
durably technically tight
sealed equipment with enhanced tightness which is equal or less than that of fugitive emissions
accomplished by enhanced maintenance and supervision
Note 1 to entry: Clauses 8, 9 and especially Clause 10 provide information on design aspects and operational
aspects to maintain tightness, permanently ensured by means of enhanced maintenance and supervision.
Note 2 to entry: Additional information can be found in EN 1127:2011, Annex B.
Note 3 to entry: ISO 5149-2 provides information on “sealed systems” and IEC 60335-2-40 on “enhanced
tightness”.
3.8
evaporator space
space inside the container containing the evaporator and air ducts
Note 1 to entry: The evaporator space corresponds to control volume III (see Annex A).
3.9
flammable atmosphere
mixture with air, under atmospheric conditions, of flammable substances in the form of gas or vapour,
which after ignition, permits self-sustained flame propagation
Note 1 to entry: For example, a mixture of flammable refrigerant fluid with air under atmospheric conditions.
[SOURCE: IEC 60079-10-1:2015, 3.2]
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ISO 20854:2019(E)
1)
3.10 flammable limit/explosive limit
3.10.1
LFL
lower flammable limit
minimum concentration of the refrigerant that is capable of propagating a flame through a homogeneous
mixture of the refrigerant and air under the specified test conditions at 23,0 °C and 101,3 kPa
[SOURCE: ISO 817:2018, 3.1.24, modified — Notes 1 and 2 have been omit
...
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