ISO/DTS 22359-2

FINAL DRAFT
Technical
Specification
ISO/TC 292
Security and resilience — Hardened
Secretariat: SIS
protective shelters —
Voting begins on:
2025-12-09
Part 2:
Requirements for shelter protective
Voting terminates on:
2026-02-03
equipment
Securité et résilience — Abris durcis —
Partie 2: Exigences pour les équipements de protection des abris
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
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Reference number
FINAL DRAFT
Technical
Specification
ISO/TC 292
Security and resilience — Hardened
Secretariat: SIS
protective shelters —
Voting begins on:
Part 2:
Requirements for shelter protective
Voting terminates on:
equipment
Securité et résilience — Abris durcis —
Partie 2: Exigences pour les équipements de protection des abris
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2025
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ii
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Common requirements for shelter protective equipment . 2
4.1 Background .2
4.2 Design service life .2
4.3 Quality of protective equipment .2
4.4 User manual .2
4.5 Equipment markings .2
4.6 Corrosion protection .3
4.7 Gaskets and other rubber or polymer parts .3
4.8 Temperature and humidity resistance .3
4.9 Fire resistance .3
4.10 Maintenance .3
4.11 Operational requirements .3
5 Blast protection . 4
5.1 General information.4
5.2 Blast doors and hatches .5
5.2.1 Blast resistance for positive, negative and rebound load .5
5.2.2 Impact load .6
5.2.3 Shock load .6
5.2.4 Additional requirements for double doors .6
5.2.5 Additional requirements for power-operated doors .7
5.2.6 Additional requirements for sliding doors.7
5.3 Blast valves for ventilation .8
5.3.1 Blast resistance for positive and negative load .8
5.3.2 Blast attenuation capacity .9
5.3.3 Impact load .9
5.3.4 Shock load .9
5.3.5 Ventilation capacity and sound power level .10
5.4 Blast valves for combustion engine exhaust system and tank vent pipe protection .10
5.4.1 Blast resistance .10
5.4.2 Blast attenuation capacity .11
5.4.3 Shock load . 12
5.4.4 Ventilation capacity and requirements to restrict exhaust system back pressure . 12
5.4.5 Heat resistance . 12
5.5 Overpressure blast valves . 13
5.5.1 Blast resistance and maintenance of overpressure and air flow in a shelter . 13
5.5.2 Blast attenuation capacity .14
5.5.3 Impact load .14
5.5.4 Shock load . 15
5.5.5 Ventilation capacity, sound power level and capability to maintain overpressure
and air flow . 15
6 Gas tightness .15
6.1 General information. 15
6.2 Gastight doors and hatches .16
6.2.1 Resistance to entry of toxic substances .16
6.2.2 Residual blast resistance .16
6.2.3 Shock load .16
6.2.4 Additional requirements for double doors .17
6.3 Gastight valves . .17

iii
6.3.1 Resistance to entry of toxic substances .17
6.3.2 Residual blast resistance .18
6.3.3 Shock load .18
6.3.4 Ventilation capacity .18
6.3.5 Additional requirements for power operated valves .19
7 Tightness of penetrations . 19
7.1 General .19
7.2 Ventilation duct penetrations .19
7.2.1 Blast resistance .19
7.2.2 Gas tightness . 20
7.3 Pipe penetrations . 20
7.3.1 Blast resistance . 20
7.3.2 Gas tightness . 20
7.4 Cable penetrations .21
7.4.1 Blast resistance .21
7.4.2 Gas tightness .21
8 Ground shock isolation .21
8.1 General information.21
8.1.1 Ground shock propagation in various soil types . 22
8.1.2 Shock spectrum for explosion induced ground shocks . 22
8.2 Shock attenuation . 22
8.2.1 Attenuation of transmitted shock force . 22
8.2.2 Limiting of transmitted displacement . 23
9 CBRN protection .23
9.1 General . 23
9.1.1 Background . 23
9.2 CBRN detection . 23
9.2.1 General information . 23
9.2.2 Functional requirements .24
9.2.3 Chemical warfare agents and toxic industrial chemicals .24
9.2.4 Biological warfare agents and other pathogens .24
9.2.5 Radiological agents and nuclear materials . 25
9.3 Upstream prefiltration of incoming air . 25
9.3.1 Prefilters and prefilter materials . 25
9.4 CBRN filtration . 26
9.4.1 Dimensioning of the CBRN filtration system . 26
9.4.2 Particle and aerosol filtration . .27
9.4.3 Filtration of toxic gases .27
9.4.4 Mechanical requirements for the CBRN filters . 28
9.4.5 System blower and ductwork . 29
9.4.6 System control devices . 29
10 Removal of carbon dioxide and addition of oxygen during shut-off mode .30
10.1 General information. 30
10.2 Removal of carbon dioxide (CO ) . 30
10.2.1 Background . 30
10.2.2 Functional requirements . 30
10.2.3 Verification of performance . 30
10.3 Addition of oxygen (O ) . . 30
10.3.1 Background . 30
10.3.2 Functional requirements .31
10.3.3 Verification of performance .31
Annex A (informative) Toxic chemical agents .32
Bibliography .34

iv
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,
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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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
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This document was prepared by Technical Committee ISO/TC 292, Security and resilience.
A list of all parts in the ISO 22359 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.

v
Introduction
This document is a part of the ISO 22359 series on hardened protective shelters, which comprises:
— ISO 22359: the document gives an overview of hardened protective shelters and presents guidelines for
their design, construction, use and maintenance;
— ISO/TS 22359-2 (this document): this document presents the minimum requirements for shelter
protective equipment, i.e. various equipment that makes a shelter safe and secure to maximize the
chances that the occupants stay alive and unharmed during their time in the shelter during a crisis.
A hardened protective shelter is a purpose-built structure, which is blast resistant (designed to withstand
the effects of a blast with a predefined force) and gastight (so completely closed that no gases can get in or
out), and which protects occupants against the effects of disasters by isolating them from the hazardous
environment. A shelter can sustain the lives of the occupants even for an extended period of time if the
anticipated threat so requires, by maintaining a sufficient internal overpressure and using purified filtered
air to prevent entry of all possible toxic substances that the ambient air can contain.
Completely isolated from the surrounding environment during a crisis, a shelter is expected to be well
equipped to protect occupants against hazards and to keep them alive and unharmed until it is safe to leave
the shelter. For these purposes, a shelter is outfitted with several types of shelter protective equipment,
which are devices specifically designed to shield and protect the enclosed shelter space, the ventilation and
air conditioning systems, as well as other installations against the effects of hazards to the shelter and its
occupants.
vi
FINAL DRAFT Technical Specification ISO/DTS 22359-2:2025(en)
Security and resilience — Hardened protective shelters —
Part 2:
Requirements for shelter protective equipment
1 Scope
This document provides functional requirements and methods for verification of performance for protective
equipment and systems necessary to guarantee a desired protection level of hardened protective shelters.
The document covers six functional categories of protective equipment available for the protection of a
hardened protective shelter:
— blast protection;
— gas tightness;
— tightness of penetrations;
— ground shock isolation;
— CBRN (chemical, biological, radiological, nuclear) protection; and
— carbon dioxide (CO ) removal and oxygen (O ) addition.
2 2
The document is intended for use by the owners of the hardened protective shelters, architects and
engineers designing them, industries producing the targeted equipment, and procurement organizations in
the construction industry sourcing such equipment.
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 22300, Security and resilience — Vocabulary
ISO 22359:2024, Security and resilience — Guidelines for hardened protective shelters
ISO 12944-2, Paints and varnishes — Corrosion protection of steel structures by protective paint systems —
Part 2: Classification of environments
ISO 16890-1, Air filters for general ventilation — Part 1: Technical specifications, requirements and classification
system based upon particulate matter efficiency (ePM)
ISO 2135:2024, Anodizing of aluminium and its alloys — Accelerated test of light fastness of coloured anodic
oxidation coatings using artificial light
ISO 29463-1, High efficiency filters and filter media for removing particles in air — Part 1: Classification,
performance, testing and marking

3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 22300, ISO 22359 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
design service life
anticipated period of time during which the equipment is expected to perform its intended function with
acceptable performance and reliability, under specified conditions, without requiring major overhaul or
replacement
3.2
shelter protective equipment
special devices designed to enclose the shelter space, ensure the supply of breathing air, maintain
overpressure, and protect the ventilation systems and other installations against the effects of hazards
4 Common requirements for shelter protective equipment
4.1 Background
The requirements outlined in Clause 4 apply to all shelter protective equipment presented in this document
unless specifically limited to concern particular group(s) of equipment. The manufacturer of the shelter
protective equipment is responsible for demonstrating the conformity of the products to these common
requirements.
4.2 Design service life
The shelter protective equipment shall have a design service life of at least 30 years; equipment embedded in
concrete shall have a design service life of at least 50 years.
4.3 Quality of protective equipment
The quality of the protective equipment shall be assured by the manufacturer.
NOTE The manufacturer can align the protective equipment with a quality management system, such as ISO 9001.
4.4 User manual
A user manual containing the necessary instructions for safe handling, use and disposal of the equipment
shall be a part of the delivery.
4.5 Equipment markings
The shelter protective equipment (excluding wall sleeves, wall frames, prefilter material and ducting) shall
be provided with permanent markings, indicating at least the following:
— name and type code of the equipment;
— name of the manufacturer;
— month and year of manufacture;
— manufacturer’s serial number.

4.6 Corrosion protection
The shelter protective equipment made of steel materials shall comply with the requirements for resistance
against environmental conditions in accordance with ISO 12944-2 applying the resistance classes given in
Table 1.
Table 1 — Corrosion protection classes for steel components
Type of equipment Class in accordance with ISO 12944-
Doors and hatches C2-C4
Blast valves C2-C4
Blast valves for exhaust systems of power generators C4-C5
Gastight valves and shut-off devices C1-C3
CBRN filtration systems C1-C3
4.7 Gaskets and other rubber or polymer parts
Gaskets and other rubber or polymer parts shall be resistant to acids and bases such as chemical warfare
agents according to the operational requirements.
[7]
NOTE Whenever available, MIL-STD 282 (method 204.1) can be used for the verification.
4.8 Temperature and humidity resistance
The range for the operational temperature of protective equipment installed inside the shelter shall be 0 °C
to 40 °C and the minimum requirement for the operational humidity range RH 40 % to RH 80 %.
The minimum range for protective equipment exposed to the outside environment shall be selected
according to the local climate conditions, covering the expected combined minimum and maximum values of
temperature and humidity.
4.9 Fire resistance
Blast doors and hatches, blast valves, overpressure blast valves and wall sleeves exposed to the outside
environment shall be designed to resist a temperature load of at least 100 °C for 10 min. This can be verified
through calculations or tests based on generally accepted and scientifically correct methods.
4.10 Maintenance
Shelter protective equipment shall be maintained regularly for their entire design service life by a competent
service provider; preferably one authorized by the manufacturer.
4.11 Operational requirements
The operational requirements referred to in this document define the specific conditions under which a
hardened protective shelter is operated, encompassing aspects such as expected threats and scenarios,
required capacities, environmental factors, necessary infrastructure, logistics, maintenance and responsible
parties. The operational requirements can be set forth, for example, in the technical specifications of the end
user or in the building contract.

5 Blast protection
5.1 General information
An explosion (such as a weapon detonation) creates an oncoming blast wave front (also called shock front),
which, when it encounters structures or other objects, generates a blast pressure uniformly distributed on
the object's surface. This pressure causes a blast load on the object; the protective equipment is designed
and dimensioned to protect against the effects of this load.
The blast load considered in the design can be positive or negative. The positive load is the load acting
against the frame where the object is fixed, and the negative load is the load acting away from the frame.
A blast event creates a rapidly rising positive pressure that decreases steadily, reaching the surrounding
atmospheric pressure, and then dropping below it, reaching a negative phase of the blast. See Figure 1.
Key
P pressure
P atmospheric pressure
P maximum positive pressure
max
P minimum negative pressure
min
t duration of the positive load
pos
t duration of the negative load
neg
t time
Figure 1 — Blast wave parameters
A hardened protective shelter is protected from a blast wave front by constructing a blast protection barrier
(see ISO 22359:2024, 4.3) around the shelter, which is able to resist the blast effects without breaking or
leaking the blast pressure into the shelter.
The blast protection barrier consists of:
— the shell of the shelter (e.g. bedrock or reinforced concrete);
— the shelter protective equipment such as blast doors, hatches, valves or wall sleeves at all apertures (e.g.
entries and exits) and penetrations (e.g. for tubes, pipes and cables) in the blast protection barrier.

5.2 Blast doors and hatches
5.2.1 Blast resistance for positive, negative and rebound load
5.2.1.1 Background
Blast doors and hatches protect the shelter entries and exits against blast pressure. When an oncoming
blast wave front hits a blast door or hatch, it first generates a positive blast load that is transmitted to the
surrounding structures through the door frame into the wall structure. As depicted in Figure 1, the blast
load then turns into a negative blast load acting away from the frame.
When the blast load causes the door plate to deform, it absorbs the potential energy of the blast wave front
like a tensioned spring. When the external blast load decreases and ceases to push the door plate against
the door frame, the potential energy stored in the door plate is released and the door plate bounces back
in a phenomenon called rebound. The rebound phenomenon generates a rebound load on the door (see
Figure 2). The rebound load and the required resistance depend on the basic natural vibration time of the
door construction.
Key
1 positive load
2 rebound load
3 negative load
i interior area
e exterior area
Figure 2 — Blast doors under positive, rebound and negative loads
5.2.1.2 Functional requirements
A blast door or hatch in a shelter as well as their frames shall be dimensioned and designed so that the
positive and negative loads described above can be transmitted to the surrounding wall structures through
the frames.
A rebound latching system restraining the door plate structure in its place, shall be designed so that the
rebound force is transmitted into the surrounding wall structure.
If the load caused by the blast is of long duration (significantly longer than the basic natural vibration time
of the door construction) then:
— the static pressure in kPa (kilopascals) is used as a basis for calculating the required blast resistance of
blast doors and hatches;
— the maximum value for the rebound load shall not exceed 0,5 × positive load.
If the load caused by the blast is of short duration (shorter than or equal to the basic natural vibration time
of the door construction) then:
— the dynamic pressure in kPa is used as basis for the calculation of the required blast resistance of blast
doors and hatches;
— the rebound load shall be determined by rigorous dynamic analysis.
The blast resistance for negative load shall not be separately calculated, as the resistance of the door against
the rebound load is a governing factor in the design of a door.

5.2.1.3 Verification of performance
The blast resistance of a blast door or hatch is verified through calculations based on generally accepted and
scientifically correct methods. Acceptable methods are static analysis in case of a long duration load and
dynamic analysis in case of a short duration load.
5.2.2 Impact load
5.2.2.1 Background
The outer surface of a shelter and objects installed into it (such as blast doors and hatches) can be exposed to
the impact of high velocity shrapnel or fragments that can penetrate unprotected objects.
5.2.2.2 Functional requirements
An exposed blast door or hatch shall be protected against the impact of shrapnel and fragments by structural
steel of minimum 20 mm thickness or reinforced concrete of minimum 200 mm thickness or by another
material with corresponding impact resistance.
5.2.2.3 Verification of performance
The resistance of a blast door or hatch against fragment penetration is verified by generally accepted and
scientifically correct methods based on the estimated momentum of the flying object and the properties of
the door material.
5.2.3 Shock load
5.2.3.1 Background
Blast doors and hatches can be subject to explosion induced in-structure ground shock loads transmitted
through shelter structures to the installation location of the doors and hatches. Depending on the type of
the soil, the acceleration caused by the shock load can be up to 30g, which can cause severe damage to the
hinges and latching mechanism of the doors and hatches due to the movement of the heavy door plate. In a
wall installation, the wall structure can exert vertical and horizontal shock forces tending to move the door
plate in relation to the frame fixed in the wall.
5.2.3.2 Functional requirements
The resistance against a shock load exerted on a blast door shall be the same as that on the structure in
which it is installed.
Sufficient shock support against the specified shock forces to the door plate shall be provided in both vertical
and horizontal directions.
5.2.3.3 Verification of performance
The resistance of a blast door or hatch against shock loads is demonstrated by design and calculations
indicating sufficient support of the door plate structure in both vertical and horizontal directions.
5.2.4 Additional requirements for double doors
5.2.4.1 Background
Double doors with two wings are missing the door jamb at the centre (see Figure 3). They are usually
substantially heavier than single wing doors.

Key
1 single wing door
2 double wing door
Figure 3 — Single and double wing doors
5.2.4.2 Functional requirements
Support of the door at the centre and the load transfer from the centre of the door into the door sill and head
shall be designed to transfer both the positive and negative loads into the door frame.
NOTE This can be achieved by, for example, providing the door wings with a centre beam or mullion to support
the wing.
The heavy door wings shall operate smoothly despite their heavy weight. The design of the door hinges shall
minimize the friction in opening and closing the door wings.
5.2.4.3 Verification of performance
The adequacy of the door wing support and load transfer from the centre of the door is verified through
calculations based on generally accepted and scientifically correct methods. Acceptable methods are static
analysis for a long duration load and dynamic analysis for a short duration load.
5.2.5 Additional requirements for power-operated doors
5.2.5.1 Background
If the blast doors and hatches are required to be remotely operated or are too heavy for manual operation,
means for power operated opening and closing of the door can be necessary. The power operation of the
door wings and latches can be effectuated, for example, by electrical or hydraulic actuators.
5.2.5.2 Functional requirements
During the opening cycle, opening of the door wing(s) shall be prevented unless the door has first been
unlatched. The door closing cycle shall be accomplished in reverse order.
A power-operated door shall be provided with a safety arrangement that stops the door movement rapidly if
any obstacle gets in the way of the door swing.
5.2.5.3 Verification of performance
The design of the power-operated door is verified through provision of its design, material and component data.
5.2.6 Additional requirements for sliding doors
5.2.6.1 Background
Instead of hinged, swinging blast doors, it can be necessary to use sliding blast doors. Sliding doors are
supported from the sill or from the head of the door frame. The door structure moves on a rail along the
surface of the installation wall.

5.2.6.2 Functional requirements
The door structure support and rail system shall enable a smooth and safe movement of the sliding blast
door between the open and closed positions.
The door shall be held in closed position by a latching system that tightens the door structure evenly against
the door frame and is designed to withstand the specified blast and shock loads.
5.2.6.3 Verification of performance
The adequacy of the support and rail system and the capability of the latching system to retain the door
structure in its position for the specified blast and shock loads are verified through calculations based on
generally accepted and scientifically correct methods. Acceptable methods are static analysis for a long
duration load and dynamic analysis for a short duration load.
5.3 Blast valves for ventilation
5.3.1 Blast resistance for positive and negative load
5.3.1.1 Background
Blast valves for ventilation are designed to protect the ventilation system of a shelter from the oncoming
blast wave front by automatically closing due to a rapidly rising positive blast pressure followed by a negative
blast pressure (see 5.1). An example of a disc-type blast valve responding to the positive and negative blast
pressures is depicted in Figure 4.
Key
1 normal ventilation position
...