ISO/FDIS 19916-4

ISO/TC 160
ISO/DIS 19916-4:2026(en)
Date: 2026-01-09
Secretariat: BSI
Date: 2026-02-02
Glass in building — Vacuum insulating glass —
Part 4:
Pendulum impact testing and classification
FDIS stage
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ISO/DISFDIS 19916-4:20252026(en)
Contents
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Test requirements . 2
4.1 General . 2
4.2 Test requirements for mode of breakage Type B. 3
4.3 Test requirements for mode of breakage Type C . 3
5 Test method . 3
5.1 Test apparatus . 3
5.2 Calibration of test apparatus . 3
5.3 Test specimens . 3
5.4 Impact test procedure . 4
6 Classification. 5
6.1 Drop height class . 5
6.2 Mode of breakage . 5
6.3 Performance classification . 5
7 Test report . 6
Annex A (normative) Fragmentation test of tempered glass in the VIG . 8
Annex B (informative) Examples of performance classification . 9

iii
Foreword
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This document was prepared by Technical Committee ISO/TC 160, Glass in building.
A list of all parts in the ISO 19916 series can be found on the ISO website.
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ISO/DISFDIS 19916-4:20252026(en)
Introduction
Accidental human impact with glass panes can be a source of injury. The classification of glass in terms of its
ability to withstand impact and the consequences of the glass breaking under such impact has been considered
in many countries. The use of a soft body impactor to represent a human body has enabled regulators, code
officials and other control organizations to specify glazing that reduces the risk of cutting and piercing injuries.
This document is based on relevant parts of the test and classification methods described in ISO 29584:2015.
ISO 29584:2015 cannot be directly applied to vacuum insulating glass. In this document, vacuum insulating
glass is categorised into two groups: Group 1 (with laminated glass or film-backed glass) in which no shear or
opening can occur, and Group 2 (without laminated glass or film-backed glass) in which disintegration can
occur when broken after impact. Performance classification is given for Group 1 as two panes separated by a
vacuum layer and for Group 2 as the complete vacuum insulating glass.
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DRAFT International Standard ISO/DIS 19916-4:2025(en)

Glass in building — Vacuum insulating glass —
Part 4:
Pendulum impact testing and classification
1 Scope
This document specifies a method to evaluate, by means of impactors described in ISO 29584:2015, safe
breakage characteristics of vacuum insulating glass (VIG) products intended to reduce cutting and piercing
injuries to persons through accidental impact.
This document does not specify the intended use of the products, but provides a method of classification in
terms of the performance of the products being tested. The impact energy used for the various levels of
classification are designed to provide the intended user or the legislator with the information to assist in
defining the level of safety and protection required relative to the intended location at which the selected
safety glass is to be used.
The products to which this document is applicable are:
— — VIG without further processing (Group 2);
— — VIG processed into a laminated glass (Group 1);
— — VIG backed with an adhesive (safety) film (Group 1).
Insulating glass units incorporating VIG are excluded from this document.
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 19916--1, Glass in building — Vacuum insulating glass — Part 1: Basic specification of products and
evaluation methods for thermal and sound insulating performance
ISO 29584:2015, Glass in building — Pendulum impact testing and classification of safety glass
ISO 12540:2017, Glass in building — Tempered soda lime silicate safety glass
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 19916-1, ISO 29548:2015 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 3.1
ply
sheet of monolithic glass
Note 1 to entry: See Figure 13.2.
3.2
pane
glass component separated by vacuum layer in vacuum insulating glass (VIG)
Note 1 to entry: See Figure 1.

a)  Vacuum insulating glass (VIG) without further processing b)  VIG processed into a laminated glass
Key
1 pane
2 ply
3 vacuum layer
4 pillar
5 edge seal
6 interlayer
1 pane
2 ply
3 vacuum layer
4 pillar
5 edge seal
6 interlayer
Figure 1 — Examples for ply and pane
4 Test requirements
4.1 4.1 General
When tested by the method given in Clause 5Clause 5,, each test specimen shall either not break or shall break
as defined in either 4.24.2 or 4.34.3.
© ISO #### 2026 – All rights reserved
ISO/DISFDIS 19916-4:20252026(en)
4.2 4.2 Test requirements for mode of breakage Type B
Numerous cracks appear, but no shear or opening is allowed within the test specimen through which a
(76 ± 1) mm diameter sphere can pass when a maximum force of 25 N is applied (in accordance with
ISO 29584:2015, Annex C).
Additionally, if particles are detached from the test specimen up to 3 min after impact, they shall, in total,
weigh no more than the mass equivalent to 10 000 mm of the original test specimen.
of the original test
The largest single particle shall weigh no more than the mass equivalent to 4 400 mm
specimen.
The mass equivalent shall be determined using the measured thickness of the ply from which the glass
particles originate.
4.3 4.3 Test requirements for mode of breakage Type C
Disintegration occurs, and the 10 largest crack-free particles of each broken ply collected within 5 min after
impact shall weigh no more than the mass equivalent to 6 500 mm of the original test specimen. The particles
shall be selected only from the portion of the original test specimen exposed in the test frame. Only the exposed
area of any particle retained in the test frame shall be taken into account in determining the mass equivalent.
The mass equivalent shall be determined using the measured thickness of the ply from which the glass
particles originate.
5 Test method
5.1 Test apparatus
It shall be in accordance with ISO 29584:2015, 5.1.
5.2 Calibration of test apparatus
It shall be in accordance with ISO 29584:2015, 5.2.
5.3 Test specimens
5.3.1 General
Each test specimen shall be representative of the normal production of the type of product submitted for test.
Test specimens shall be categorized into one of the following two groups in terms of type of mode of breakage
defined in 6.26.2.
Group 1: VIG in which mode of breakage of at least one pane is Type B defined in 6.26.2.
Group 2: VIG not covered by Group 1.
5.3.2 Dimensions of the test specimens
InThey shall be in accordance with ISO 29584:2015, 5.3.2.
5.3.3 Number of test specimens
InIt shall be in accordance with ISO 29584:2015, 5.3.3.
5.3.4 Preparation of the test specimens
Remove all masking and protection material from the test specimens and condition for a minimum of 12 h at
(20 ± 5) °C.
To help with identification of any detached particles after impact, a thin layer of paint may be applied over the
whole surface of one side of the test specimen prior to testing. It shall be ensured that the applied paint does
not affect the pendulum impact performance of the test specimen.
NOTE Paints that have been found to be suitable for this application are Engineers Layout Iink, blanc de Meudon
1 1)
and India ink.
5.4 Impact test procedure
Testing shall be in accordance with ISO 29584:2015, 5.4.2 to 5.4.5 of ISO 29584:2015, with the exception that
the impactor should be raised to the intended drop height.
Inspect each pane in the VIG test specimen after impact and note whether
a) a) that pane remains unbroken, or
b) b) it broke in accordance with either the requirements of 4.24.2 or 4.34.3,, or
c) c) it broke and failed to conform to the requirements of 4.24.2 or 4.34.3.
For Group 1, if both panes in any of the four test specimens fail to conform to the requirements of 4.24.2 or
4.34.3,, terminate the procedure. If the same or bot
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