ISO 13216-3:2018

Road vehicles - Anchorages in vehicles and attachments to anchorages for child restraint systems - Part 3: Classification of child restraint system and space in vehicle

This document classifies the spatial requirements in a vehicle to enable a child restraint system (CRS) to be conveniently mounted. It also specifies the dimensions of child restraint systems, to ensure that they will fit in vehicles. A classification scheme is provided to determine dimensional compatibility between child restraint systems and the available space at specified seating positions in vehicles. The dimensional requirements refer to forward-facing child restraint systems of three size categories, rearward-facing child restraint systems of three size categories, and lateral-facing child restraint systems of two categories. This edition of the document also incorporates size classification of booster systems.

Véhicules routiers — Ancrages dans les véhicules et attaches aux ancrages pour systèmes de retenue pour enfants — Partie 3: Classification des dimensions des retenues pour enfants et espace dans le véhicule

General Information

• Status: Published
• Publication Date: 17-Oct-2018
• ICS: 43.040.80 - Crash protection and restraint systems
• Technical Committee: ISO/TC 22/SC 36 - Safety and impact testing
• Drafting Committee: ISO/TC 22/SC 36/WG 2 - Child restraint systems
• Current Stage: 9093 - International Standard confirmed
• Start Date: 07-Mar-2024
• Completion Date: 13-Dec-2025

Relations

• Revises: ISO 13216-3:2006 - Road vehicles - Anchorages in vehicles and attachments to anchorages for child restraint systems - Part 3: Classification of child restraint dimensions and space in vehicle
• Effective Date: 04-Nov-2015

Overview

ISO 13216-3:2018 - "Road vehicles - Anchorages in vehicles and attachments to anchorages for child restraint systems - Part 3" specifies how to classify the spatial compatibility between vehicles and child restraint systems (CRS). The standard defines child restraint envelopes and fixtures (CRF), maximum CRS dimensions, and a classification scheme so manufacturers, OEMs and testing labs can determine whether a given CRS will fit a specific vehicle seating position. The 2018 edition also incorporates booster system envelopes and updated lateral- and rearward-facing envelopes.

Key topics and technical requirements

• Classification of CRS and vehicle space
  • Three size categories for forward‑facing CRS, three for rearward‑facing CRS, and two for lateral‑facing CRS.
  • Booster envelopes added (ISO/B1, ISO/B2, ISO/B3) for booster seat/cushion size classification.
• Child restraint envelopes and CRF
  • Envelopes simulate CRS geometry for dimensional compatibility checks; CRFs are physical implementations used in vehicle testing.
  • CRF masses recommended for realistic seat compression (examples from the standard: R1 = 10 ±1 kg, R3 = 13 ±1 kg, B1 = 3 ±1 kg).
• Vehicle installation and assessment rules
  • Seat adjustment requirements when checking fit (e.g., seat to rearmost and lowest positions; front seat mid‑position for rear seating checks).
  • Typical CRS pitch angle for checks: 15° ± 10°.
  • Interference criteria: envelope must be accommodated without significant contact with head restraints, dashboards, windshields or front seats.
• Virtual assessment
  • Use of CAD and virtual tools is permitted provided they represent physical installation parameters (mass, center of gravity, seat compression).
• Marking and consumer guidance
  • Informative Annex A suggests marking schemes for vehicle seating positions and CRS dimensions to help consumers choose compatible products.

Practical applications and users

• Vehicle manufacturers (OEMs) - design seat geometry and ISOFIX/anchorage locations to accommodate common CRS envelopes.
• Child restraint manufacturers - size and mark CRS to show dimensional class compatibility with vehicles.
• Test laboratories and conformity assessors - perform physical and virtual compatibility checks using CRFs and envelope definitions.
• Regulators and standards bodies - adopt classification for vehicle type approvals and consumer safety information.
• Consumers and retailers - use vehicle/CRS markings and classifications to select dimensionally compatible child seats and boosters.

Related standards

• ISO 13216-1:1999 - Seat bight anchorages and attachments (normative reference for anchorage positioning and geometry).
• Other parts of the ISO 13216 series for ISOFIX and anchorage requirements.

Keywords: ISO 13216-3:2018, child restraint system, CRS, child restraint envelope, CRF, ISOFIX, booster system, vehicle seating compatibility, CRS dimensions.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 13216-3
Second edition
2018-10
Road vehicles — Anchorages
in vehicles and attachments to
anchorages for child restraint
systems —
Part 3:
Classification of child restraint system
and space in vehicle
Véhicules routiers — Ancrages dans les véhicules et attaches aux
ancrages pour systèmes de retenue pour enfants —
Partie 3: Classification des dimensions des retenues pour enfants et
espace dans le véhicule
Reference number
©
ISO 2018
© ISO 2018
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
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CH-1214 Vernier, Geneva
Phone: [phone]
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Published in Switzerland
ii © ISO 2018 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Vehicle space requirements . 2
4.1 Space required in a vehicle to accommodate specified types and installation
modes of child restraint systems. 2
4.1.1 General. 2
4.1.2 Mass of CRF . 2
4.1.3 Installation and assessment using virtual tools and procedures . . 3
4.2 Space required for full-height forward-facing toddler child restraint systems . 3
4.3 Space required for reduced-height forward-facing toddler child restraint systems . 3
4.4 Space required for reduced-height forward-facing toddler child restraint systems
having a reduced contour in the upper part, and an extended seatback upper part . 3
4.5 Space required for full-size rearward-facing toddler child restraint systems . 6
4.6 Space required for reduced-size rearward-facing toddler child restraint systems . 7
4.7 Space required for rearward-facing infant child restraint systems . 7
4.8 Space required for lateral-facing infant child restraint system (carry-cot) . 7
4.9 Space required for booster seat and booster cushion.13
4.9.1 Purpose of the booster system envelopes for determination of space and
seat belt alignment in vehicles .13
4.9.2 Installation requirements .13
4.9.3 Belt routing requirements .13
4.9.4 Installation with ISOFIX support .13
4.9.5 Installation without ISOFIX support .14
5 Dimensions of child restraint system .18
5.1 Maximum dimensions of child restraint systems .18
5.2 Full-height forward-facing toddler child restraint system .18
5.3 Reduced-height forward-facing toddler child restraint system .18
5.4 Reduced-height forward-facing toddler child restraint systems with a reduced
contour in the upper part, and an extended seatback upper part .19
5.5 Full-size rearward-facing toddler child restraint system.19
5.6 Reduced-size rearward-facing toddler child restraint system .19
5.7 Rearward-facing infant child restraint systems .19
5.8 Lateral-facing infant child restraint systems .19
5.9 Booster seat and booster cushion restraint systems .19
5.9.1 Purpose of the booster system envelopes with regard to child restraint
systems .19
5.9.2 Maximum dimensional requirements .19
5.9.3 Booster with ISOFIX additional requirements .20
5.10 Procedure for checking CRS compliance with CRF .20
5.11 Installation and assessment using virtual tools and procedures .20
6 Classification system .20
Annex A (informative) Marking of vehicle seating positions and child restraint systems .22
Annex B (informative) Drawings and tools .24
Bibliography .25
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 22, Road vehicles, Subcommittee SC 36.
This second edition cancels and replaces the first edition (ISO 13216-3:2006), which has been
technically revised.
The main changes compared to the previous edition are as follows:
— Addition of booster system envelopes ISO/B3, ISO/B2 and ISO/B1;
— Addition of envelope ISO/R2X (modified version of ISO/R2 to provide improved compatibility with
the vehicle interior);
— Improved version of the lateral facing envelope (ISO/L1 and ISO/L2);
— Dashed line in seatback area of the ISO/R series of envelopes;
— Corrections in the following envelope drawings: Figures 3, 5 and 7; and
— Addition of recommended CRF masses (Table 1).
A list of all parts in the ISO 13216 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 © ISO 2018 – All rights reserved

Introduction
The basic ISOFIX standard ISO 13216-1 provides requirements needed for positioning of the seat bight
anchorages, the geometry around anchorage points and, to some extent, dimensional requirements for
forward-facing child restraint systems.
In order to ensure that a child restraint system fits in a vehicle, it is also essential that the vehicle interior
and the child restraint system match each other spatially. This document provides requirements for the
space needed in vehicles to accommodate child restraints of different types and sizes.
Not all vehicles on the market are capable of accommodating the largest child restraint systems.
This document thus provides a classification system to help in judging which types and sizes of child
restraint systems will fit in the vehicle. Three size classes of forward-facing systems and three size
classes of rearward-facing systems are provided. Two classes of lateral-facing systems are included
(dimensionally revised in this second edition). This second edition also incorporates booster system
envelopes for size classification of booster systems.
A suggested marking of the space available for the respective child restraint positions in the vehicle,
and for the child restraint system dimensions, is included in this document to help consumers choose
a child restraint system that is dimensionally suitable for their vehicle. This information is shown in
informative Annex A.
INTERNATIONAL STANDARD ISO 13216-3:2018(E)
Road vehicles — Anchorages in vehicles and attachments
to anchorages for child restraint systems —
Part 3:
Classification of child restraint system and space in vehicle
1 Scope
This document classifies the spatial requirements in a vehicle to enable a child restraint system (CRS)
to be conveniently mounted. It also specifies the dimensions of child restraint systems, to ensure that
they will fit in vehicles.
A classification scheme is provided to determine dimensional compatibility between child restraint
systems and the available space at specified seating positions in vehicles. The dimensional requirements
refer to forward-facing child restraint systems of three size categories, rearward-facing child restraint
systems of three size categories, and lateral-facing child restraint systems of two categories. This
edition of the document also incorporates size classification of booster systems.
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 13216-1:1999, Road vehicles — Anchorages in vehicles and attachments to anchorages for child
restraint systems — Part 1: Seat bight anchorages and attachments
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 13216-1 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http: //www .electropedia .org/
— ISO Online browsing platform: available at https: //www .iso .org/obp
3.1
child restraint envelope
envelope simulating the dimensions of a child restraint system of a specified class, used in this document
to evaluate the space available for child restraint systems in a vehicle at a specified seating position
Note 1 to entry: The child restraint envelope is also used to identify the dimensional class for a given child
restraint system.
3.2
child restraint fixture
CRF
physical implementation of the envelope dimensions
3.3
booster system envelope
envelope describing a booster seat or a booster cushion
3.4
interference
significant contact with the vehicle interior that impedes the installation of the fixture
4 Vehicle space requirements
4.1 Space required in a vehicle to accommodate specified types and installation modes
of child restraint systems
4.1.1 General
Determination of space available in vehicle for child restraint systems is done by use of child restraint
envelopes in CAD or physical fixtures (CRF).
It shall be possible to accommodate the child restraint envelopes/fixtures, specified in this document at
a specified seating position in a vehicle, without interference with the vehicle interior elements, such as
head restraints, dashboard, windshield, or the vehicle seat in front of the seating position.
When checking the child restraint envelope/fixture on a seat, the vehicle seat shall be adjusted
longitudinally to its rearmost position and its lowest position.
In addition, when checking the child restraint envelope/fixture in a rear seating position, the related
vehicle front seat shall be adjusted as follows:
— longitudinally, to the mid-position between the rearmost position and the foremost position;
— vertically, to the mid position of its height adjustment, if not otherwise recommended by the vehicle
manufacturer; and
— the seat backrest may be adjusted, but not to a more upright angle than corresponding to a torso
angle of 15°.
NOTE 1 The angle can be measured according to ISO 6549.
The requirements apply for the child restraint envelope/fixture when positioned in the anchorages. It
is not required that the child restraint fixture shall move in and out of the seat under these conditions.
Adjustable attachments (adjustable longitudinally between −10 mm and +70 mm) may be used to
facilitate the interference checking. Envelope illustrations are showing the most extended position.
When installed on a vehicle seat, the child restraint envelopes in 4.2 to 4.9 should have a pitch angle
of 15° ± 10°, which corresponds to a clockwise rotation of the side view (upper-right drawing) in
Figures 1 to 11.
NOTE 2 The ISO/F, ISO/R and ISO/B envelope series are fully modular in size, except for the "X" versions. This
means that a vehicle compatible with the larger envelope is also compatible with the smaller one(s) of the same
category. For example, a vehicle seating position accommodating ISO/R3 also accommodates ISO/R2 and ISO/R1.
4.1.2 Mass of CRF
Child restraint fixtures for practical testing should have a mass according to Table 1 to obtain a realistic
compression of the vehicle seat.
2 © ISO 2018 – All rights reserved

Table 1 — CRF masses
Envelope / CRF Mass (kg) Tolerance (kg)
a
R1 10 ±1,0
a
R2 / R2X 10 ±1,0
R3 13 ±1,0
L1 / L2 13 ±1,0
a
F2 / F2X 13 ±1,0
F3 13 ±1,0
B1 3 ±1,0
B2 7 ±1,0
B3 7 ±1,0
a
ISOFIX base mass taken into account.
4.1.3 Installation and assessment using virtual tools and procedures
When using virtual tools for the assessment of the envelopes in a vehicle interior, the assessments shall
be representative of installing a physical fixture in a vehicle seating position, e.g. with regard to CRF
mass, centre of gravity, vehicle seat compression and extent of interference.
4.2 Space required for full-height forward-facing toddler child restraint systems
The vehicle seating position accommodates a full-height forward-facing toddler CRS. The child restraint
envelope according to Figure 1 can be positioned without interference with the vehicle interior when
installed as in 4.1.
4.3 Space required for reduced-height forward-facing toddler child restraint systems
The vehicle seating position accommodates a reduced-height forward-facing toddler CRS. The child
restraint envelope according to Figure 2 can be positioned without interference with the vehicle
interior when installed as in 4.1.
4.4 Space required for reduced-height forward-facing toddler child restraint systems
having a reduced contour in the upper part, and an extended seatback upper part
The vehicle seating position accommodates a reduced-height forward-facing toddler CRS having a
reduced contour in the upper part (to allow fitting in low-roof cars), and an extended upper part of the
seatback. The child restraint envelope according to Figure 3 can be positioned without interference
with the vehicle interior when installed as in 4.1.
Dimensions in millimetres
Key
1 limits in the forward and upward directions
2 dashed line marks the area where a support leg, or similar, may protrude
3 shape of CRF for positioning purpose in ISO 13216-1 (for reference)
4 further specifications of the connector area, see detail Y and ISO 13216-1:1999, Figures 2 and 3
Figure 1 — Envelope dimensions for a full-height forward-facing CRS — ISO/F3
4 © ISO 2018 – All rights reserved

Dimensions in millimetres
Key
1 limits in the forward and upward directions
2 dashed line marks the area where a support leg, or similar, may protrude
3 shape of CRF for positioning purpose in ISO 13216-1 (for reference)
4 further specifications of the connector area, see detail Y and ISO 13216-1:1999, Figures 2 and 3
Figure 2 — Envelope dimensions for a reduced-height forward-facing CRS, height 650 mm —
ISO/F2
Dimensions in millimetres
Key
1 limits in the forward and upward directions
2 dashed line marks the area where a support leg, or similar, may protrude
3 shape of CRF for positioning purpose in ISO 13216-1 (for reference)
4 further specifications of the connector area, see detail Y and ISO 13216-1:1999, Figures 2 and 3
Figure 3 — Envelope dimensions for a reduced-height forward-facing CRS having a reduced
contour in the upper part, and an extended seatback upper part — ISO/F2X
4.5 Space required for full-size rearward-facing toddler child restraint systems
The vehicle seating position accommodates a
...