ISO 11999-9:2025

International
Standard
ISO 11999-9
Second edition
PPE for firefighters — Test methods
2025-04
and requirements for PPE used
by firefighters who are at risk of
exposure to high levels of heat
and/or flame while fighting fires
occurring in structures —
Part 9:
Fire hoods
Équipement de protection personnelle pour pompiers —
Méthodes d'essai et exigences pour les équipements de protection
personnelle utilisés par les pompiers qui sont à risque d'une
exposition à des niveaux élevés de chaleur et/ou de flamme quand
la lutte contre les incendies survient dans les structures —
Partie 9: Cagoules
Reference number
© ISO 2025
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Published in Switzerland
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 General design requirements . 2
4.1 General .2
4.2 Innocuousness .3
4.3 Flexibility.3
4.4 Facial opening . .3
4.5 Yoke interface area .3
4.6 Sizing .3
4.7 Labels .3
4.8 Seam construction .3
4.9 Particulate protection .3
5 Sampling and pre-treatment . . 4
6 Performance requirements . . 5
6.1 General .5
6.2 Limited flame spread .5
6.2.1 General .5
6.2.2 Flame resistance (surface ignition) .5
6.2.3 Flame resistance (bottom edge) .6
6.3 Heat resistance .7
6.4 Heat transfer (flame exposure) .7
6.5 Heat transfer (radiant exposure) .7
6.6 Heat transfer (combined flame and radiant exposure) .7
6.7 Residual strength of material following radiant heat exposure .8
6.8 Seam bursting strength .8
6.9 Dimensional change .8
6.10 Thread heat resistance.8
6.11 Particulate protection .8
6.12 Water vapour resistance.8
7 Complete fire hood test - opening size retention test . 9
8 Report . 9
9 Compatibility . 9
10 Marking . . 9
11 Information supplied by manufacturer . 9
Annex A (normative) Donning, doffing and shape retention test .10
Annex B (normative) Particulate test .11
Annex C (normative) Determination of property values .12
Annex D (normative) Uncertainty of measurement .13
Bibliography .15

iii
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 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)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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 94, Personal safety — Protective clothing and
equipment, Subcommittee SC 14, Fire-fighters' personal equipment.
This second edition cancels and replaces the first edition (ISO 11999-9:2016), which has been technically
revised.
The main changes are as follows:
— the design requirement have been amended and added to (particulate protection)
— all the heat and flame properties have been brought to amended single levels (see Table 1);
— all the mechanical properties have been brought to amended single levels (see Table 1);
— additional tests have been added or changed (including resistance evaporative transfer (RET), size
retention)
A list of all parts in the ISO 11999 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.

iv
International Standard ISO 11999-9:2025(en)
PPE for firefighters — Test methods and requirements for
PPE used by firefighters who are at risk of exposure to high
levels of heat and/or flame while fighting fires occurring in
structures —
Part 9:
Fire hoods
1 Scope
This document specifies the minimum design and performance requirements for a fire hood as part of
personal protective equipment (PPE) to be used by firefighters, primarily but not solely to protect against
exposure to flame, high thermal loads and particulate protection.
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 3146, Plastics — Determination of melting behaviour (melting temperature or melting range) of semi-
crystalline polymers by capillary tube and polarizing-microscope methods
ISO 3175-2, Textiles — Professional care, drycleaning and wetcleaning of fabrics and garments — Part 2:
Procedure for testing performance when cleaning and finishing using tetrachloroethene
ISO 5077, Textiles — Determination of dimensional change in washing and drying
ISO 6942:2022, Protective clothing — Protection against heat and fire — Method of test: Evaluation of materials
and material assemblies when exposed to a source of radiant heat
ISO 8559-1:2017, Size designation of clothes — Part 1: Anthropometric definitions for body measurement
ISO 9151, Protective clothing against heat and flame — Determination of heat transmission on exposure to flame
ISO 11092, Textiles — Physiological effects — Measurement of thermal and water-vapour resistance under
steady-state conditions (sweating guarded-hotplate test)
ISO 11999-1:2024, PPE for firefighters — Test methods and requirements for PPE used by firefighters who are at
risk of exposure to high levels of heat and/or flame while fighting fires occurring in structures — Part 1: General
ISO 11999-2, PPE for firefighters — Test methods and requirements for PPE used by firefighters who are at risk of
exposure to high levels of heat and/or flame while fighting fires occurring in structures — Part 2: Compatibility
ISO 13688:2013+Amd 1:2021, Protective clothing — General requirements
ISO 13935-2, Textiles — Seam tensile properties of fabrics and made-up textile articles - Part 2: Determination
of maximum force to seam rupture using the grab method
ISO 13938-1, Textiles — Bursting properties of fabrics — Part 1: Hydraulic method for determination of bursting
strength and bursting distension

ISO 13938-2, Textiles — Bursting properties of fabrics — Part 2: Pneumatic method for determination of
bursting strength and bursting distension
ISO 15025:2016, Protective clothing — Protection against flame — Method of test for limited flame spread
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 16900-5:2016/A1:2018, respiratory protective devices – Methods of test and test equipment – Part 5:
Breathing machine, metabolic simulator, RPD headforms and torso, tools and verification tools
ISO 17492, Clothing for protection against heat and flame — Determination of heat transmission on exposure to
both flame and radiant heat
ISO 17493, Clothing and equipment for protection against heat — Test method for convective heat resistance
using a hot air circulating oven
ISO/TR 19591, Personal protective equipment for firefighters — Standard terms and definitions
NFPA 1970 (1971)-2025, Standard on Protective Ensembles for Structural and Proximity Fire Fighting, Work
Apparel and Open-Circuit Self-Contained Breathing Apparatus (SCBA) for Emergency Services, and Personal
Alert Safety Systems (PASS)
ASTM F2299/F2299M-24, Standard Test Method for Determining the Initial Efficiency of Materials Used in
Medical Face Masks to Penetration by Particulates Using Latex Spheres
3 Terms and definitions
For the purposes of this document, the terms and definitions in ISO/TR 19591 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— IEC Electropedia: available at https:// www .electropedia .org/
— ISO Online browsing platform: available at https:// www .iso .org/ obp
3.1
fire hood
item worn directly in contact with the head to protect exposed parts of the head and neck where the
protective coat/helmet/respiratory protective device (RPD) facepiece interface
3.2
particulate protection
barrier layer that principally inhibits airborne particles of solid or liquid substance in the finely divided state
3.3
yoke
area of the fire hood interfacing with the coat
4 General design requirements
4.1 General
General requirements which are not specifically covered in this document shall be in accordance with
ISO 13688 and ISO 11999-1.
The design requirements for fire hood, the face mask of RPD and helmet (including shikoro) shall be verified
by visual inspection during the procedure laid out in ISO 11999-2.
NOTE Shikoro requirements, providing coverage of the neck, ears, chin, and facial area, are covered in ISO 11999-5.

4.2 Innocuousness
Acceptability of materials in relation to innocuousness shall be according to ISO 13688:2013+Amd 1:2021,
4.2 with due consideration to Note 1 and Annex F, materials shall not release substances generally known to
be toxic, carcinogenic, mutagenic, allergenic, toxic to reproduction or otherwise harmful.
4.3 Flexibility
The fire hood shall fit close to the head and be able to be worn without discomfort. It shall not restrict head
movement, reduce the field of view, or interfere with use of the respiratory protective device. The fire hood
shall also be compatible with the respiratory device.
NOTE 1 Excess material in the construction of the fire hood may hamper the wearer and compromise the wearing
of other personal protective equipment.
4.4 Facial opening
The fire hood shall have a facial opening creating an interface to fit around an RPD face mask.
The design requirements specified shall be verified by visual inspection during the procedure laid out in
ISO 11999-2.
4.5 Yoke interface area
The fire hood shall have a yoke creating an interface with the protective coat (see ISO 11999-3) that stays
secure under the protective coat without being attached.
The design requirements specified shall be verified by visual inspection during the procedure laid out in
ISO 11999-2.
NOTE The yoke is not always symmetrical on the back, upper shoulders and front (upper chest).
4.6 Sizing
The fire hood shall be manufactured in various sizes or be sufficiently elastic to be compatible with various
head sizes, shapes and hair styles. The design requirements specified shall be verified by visual inspection
during the procedures in Annex A.
NOTE Overstretching has the potential to reduce the thermal protection.
4.7 Labels
The label(s) for the marking requirement shall be positioned in the area defined as the front dorsal plane of
the yoke of the fire hood. Assess by visual inspection.
4.8 Seam construction
Seams shall be constructed to give the minimum loss of strength and to maintain the integrity of the fire
hood. Seams shall meet the requirements of 6.2.
4.9 Particulate protection
The fire hood shall meet the requirements in 6.11 and 6.12 and the requirements in this sub-clause.
The particulate protection surface shall include at least the area from 50 mm below the side of the neck
point, and from 100 mm below both the front of the neck point and back of the neck point up to the top of the
head as defined in ISO 8559-1:2017, Figure 1.

The elastic and stitching around the facial opening shall be permitted to exclude particulate blocking
material specifically for meeting the requirements of 4.2 for a distance of (20 ± 2) mm from the leading edge
of the fire hood face opening to the innermost row of stitching.
Dimensions in millimetres
Key
1 top of fire hood
2 face opening
3 base neck line with neck points at back, front and sides (see ISO 8559-1:2017, 3.1.6-3.1.8 and 3.2.1)
shaded area of fire hood
Figure 1 — Fire hood with particulate protection area (shaded)
The distance shall be checked in at least 6 locations with the fire hood lying on a flat surface with the face
opening facing upwards.
Fire hoods meeting the requirements of this subclause shall include the label wording equivalent to “This
fire hood provides limited particulate protection" (see also Clause 10).
5 Sampling and pre-treatment
5.1 The number and size of specimens for the different tests shall be in accordance with the respective
test method.
5.2 Where specified, the test samples shall be pre-treated by cleaning. The cleaning shall be in line with
the manufacturer’s instructions on the basis of standardized processes.
NOTE Manufacturer’s instructions typically indicate one or several of the various methods and processes of
ISO 6330, ISO 15797, ISO 3175-2 or equivalent as standardized processes for cleaning.
Samples shall be subjected to five cleaning cycles with a normal load in a front loading horizontal drum
machine using non-phosphate reference detergent No 3 in soft water in accordance with the procedures of
ISO 6330 at 60 °C normal wash (6 N). The dry procedure of ISO 6330 shall be F tumble dry at low temperature
(max 60 °C) measured at the outlet temperature. Materials that are labelled as dry-clean only shall be dry
cleaned five times in accordance with ISO 3175-2.
5.3 Unless otherwise specified in the specific test methods, all specimens shall be conditioned fo
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