ICS 81.040.20  
 
Reference number
DRS 397-5: 2023
© RSB2023
  
 RWANDA 
STANDARD  DRS
397-5
First edition
2023-mm- dd
Use of glass in building — 
Part 5: Safety related to human impact  
   
DRS 397-5: 2023 
©RSB 2023- All rights reserved                  ii 
 In order to match with technological development and to keep continuous progress in industries, 
standards are subject to periodic review. Users shall ascertain that they are in possession of the latest 
edition 
 
 
 
 
 
 
 
 
© RSB2023 
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized 
in any form or by any means, electronic or mechanical, including photocopying and microfilm, without 
prior written permission from RSB. 
Requests for permission to reproduce this document should be addressed to: 
Rwanda Standards Board 
P.O Box 7099 Kigali-Rwanda 
KK 15 Rd, 49 
Tel. +250 788303492 
Toll Free: 3250 
E-mail: info@rsb.gov.rw  
Website: www.rsb.gov.rw  
ePortal: www.portal.rsb.gov.rw  DRS 397-5: 2023 
iii                ©RSB2023- All rights reserved 
 Contents Page 
Foreword ............................................................................................................................................................ iv  
1 Scope ...................................................................................................................................................... 1  
2 Normative references ............................................................................................................................ 1  
3 Terms and definitions ........................................................................................................................... 1  
4 Application ............................................................................................................................................. 1  
5 Criteria for human impact safety ......................................................................................................... 2  
5.1 General ................................................................................................................................................... 2  
5.2 Safety glass ............................................................................................................................................ 2  
5.3 Critical location ...................................................................................................................................... 3  
5.4 Manifestation (making glass visible) ................................................................................................... 6  
5.5 Identification of safety glass ................................................................................................................ 7  
5.6 Test requirements ................................................................................................................................. 7  
5.6.1 Fragmentation test ................................................................................................................................ 7  
5.6.2 Mechanical strength .............................................................................................................................. 7  
6 Safety related to glass handling, transportation and storage .......................................................... 8  
6.1 Glass handling and transportation safety considerations................................................................ 8  
6.2 Glass storage safety considerations................................................................................................... 9  
 DRS 397-5: 2023 
©RSB 2023- All rights reserved                  iv 
 Foreword 
Rwanda Standardsarepreparedby Technical Committees and approved by Rwanda Standards Board (RSB) 
Board of Directors in accordance with the procedures of RSB, in compliance with Annex 3 of the WTO/TBT 
agreement on the preparation, adoption and application of standards. 
The main task of technical committees is to prepare national standards. Final Draft Rwanda Standards 
adopted by Technical committees are ratified by members of RSB Board of Directors for publication and 
gazettment as Rwanda Standards. 
DRS 397-5 was prepared by Technical Committee RSB/TC 009, Civil engineering and building materials.  
In the preparation of this standard, reference was made to the following standards: 
1) AS 1288, Glass in buildings – Selection and installation  
2) BS 6262-4: 2018, Code of practice for glazing for buildings  
3) IS 3548, Code of practice for glazing in building  
4) IS 16232-4:2019, Use of glass in buildings — Code of practice — Part 4: Safety related to human impact  
The assistance derived from the above source is hereby acknowledged with thanks. 
DRS 397 consists of the following parts, under the general title Use of glass in building  
─ Part 1: Terminology 
─ Part 2: General methodology for selection 
─ Part 3: Energy and light 
─ Part 4: Fire and loading 
─ Part 5: Safety related to human impact 
 
 
 
 DRS 397-5: 2023 
v                ©RSB2023- All rights reserved 
  
Committee membership  
The following organizations were represented on the Technical Committee on Civil engineering and building 
materials (RSB/TC 009) in the preparation of this standard. 
Advanced Construction Technology Services (ACTS) Rwanda 
AFRIPRECAST  
Bridge to Prosperity 
City of Kigali 
Greenpact Africa 
Ministry of Health 
Mass Design Group 
Rwanda Housing Authority (RHA) 
Rwanda Transport Development Agency (RTDA) 
Standards for Sustainability (SfS) 
University of Rwanda – College of Science and Technology (UR-CST) 
Rwanda Standards Board(RSB) – Secretariat DRS 397-5: 2023 
©RSB 2023- All rights reserved                  vi 
 Introduction 
Glazing is an important item in building construction and glass, the primary glazing element has to be selected 
to cater for several requirements. Fixing of glass is a specialized operation, when properly done, will avoid the 
hazards of broken glass. Growing trend in resorting to glazed windows/doors in buildings and structures has 
considerably increased the importance of glazing and the need for proper workmanship.  
This standard on Code of practice for use of glass in buildings  is envisaged to address the above concerns 
and their engineering aspects, and is brought out in various parts as listed in the foreword.  
DRS397-5 is intended to provide guidance with respect to human impact safety while using glazing in 
buildings. 
 DRS 397-5: 2023 
1                ©RSB2023- All rights reserved 
 Use of glass in building— Part 5: Safety related to human impact 
1 Scope 
This Draft Rwanda Standard covers selection, handling, installation and manifestation of glass in buildings, 
subject to safety with respect to human impact of the occupants.  
This standard does not cover the following:  
a) glazing system including frameless glazing system; and 
b) patent glazing. 
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. 
RS 397-1 , Use of glass in building ― Part 1: Terminology  
RS 397-2 , Use of glass in building ― Part 2: General methodology for selection 
DRS 397-4 , Use of glass in building ― Code of practice — Part 4: Fire and loading 
RS ISO 12543-4 , Glass in building ― Laminated glass and laminated safety glass ― Part 4: Test methods for 
durability   
3 Terms and definitions 
For the purposes of this standard, the terms and definitions given in RS 397-1apply. 
4 Application 
While selecting the glass for application, the structural performance and required glass thickness shall satisfy 
the following criteria: 
c) glazing thickness calculation subjected to wind load is calculated in accordance DRS 397-4; and 
d) for a given application, the type and thickness of glass selected shall be in accordance with RS 397-2.  
©RSB 2023- All rights reserved                  2 
 5 Criteria for human impact safety 
5.1 General 
5.1.1 The provisions herein are limited to the behaviour of glass when subjected to various kinds of human 
impact, precautions against risk of fall and falling glass. Conditions outside of ‘human impact’ are not covered 
under this clause.  
5.1.2 This standard does not assume that the glass used in accordance with this standard is not to be 
broken under all human impact conditions, rather: 
a) it will not be broken under most likely forms of human impact; and  
b) even if it breaks, the likelihood of cutting or piercing injuries will be minimized by virtue of the protection 
given to the glass, or by the limited size or increased thickness, or by the fracture characteristics of the glass. 
5.1.3 Further, this standard does not deal with the safety and security of people or goods in relation to risks 
of:  
a) vandalism, riots, burglary or break in protection,  
b) fire arm protection,  
c) protection from explosion (terrorist attack),  
d) natural disasters like earthquakes, cyclone, fire, etc,  
e) plastic glazing material, safety and security glazing, etc.  
5.1.4 In circumstances wherein the requirements of any referenced standard(s) exceed the requirements of 
this standard, in such case(s) the higher requirement shall become applicable.  
5.1.5 The use of this standard shall also be in conformity with all other relevant standards in force including 
those on fire safety, structural stability, natural disasters, safety and security. 
5.2 Safety glass 
5.2.1 Glazing material that are constructed, treated, or combined with other materials so as to reduce, in 
comparison with ordinary sheet/float/plate glass, the likelihood of injury to persons by objects from exterior 
sources or by these safety glasses when they may be cracked or broken.  
5.2.2 The following products may be used in safety glazing provided that they meet the conformity 
requirements in RS 397-2: 
a) Toughened Safety (Tempered) Glass (TS); 
b) Toughened Float Safety Glass (TF); 
c) Laminated Safety Glass (LS); and DRS 397-5: 2023 
3                ©RSB2023- All rights reserved 
 d) Laminated Float Safety Glass (LF). 
NOTE All heat-treated glasses are not safety glasses and all laminated, toughened, coated glasses are not safety 
glasses. Heat-strengthened glasses and annealed glasses are not classified as safety glasses unless laminated to meet 
the requirements of tests specified for safety glass. 
5.3 Critical location 
5.3.1 Where any glazing is within 1.5 m above the floor level of a building, it is considered likely to be 
subjected to human impact and hence, shall comply with the human impact safety requirements of this 
section. Safety glazing should also be used:  
a) where there is danger of falling infill glass material(s) from overhead glazing; 
b) the danger of falling due to a change in floor level; and 
c) in case of balustrades, stairs and floors. 
5.3.2 When the glazing is required to remain in position on impact and be unbroken, or when the glazing is 
not fully framed on all edges, the designer or specifier should seek advice from the manufacturer. 
5.3.3 Based on typical accidents in glazed buildings, certain locations in buildings are found to be more 
vulnerable to human impact than others. Some of such critical locations are shown in Figure 1, where 
necessary precautions have to be followed: 
a) in-and-around doors, low windows; 
b) door side anels; 
c) panels mistaken for a doorway or opening; 
d) panels at low levels in walls and partitions; 
e) bathrooms; 
f) building associated with special activities, e.g., gymnasia, enclosed swimming pools, etc; 
g) schools and child care facilities; and 
h) nursing homes and care facilities for the aged and infirmed. 
5.3.4 Suitable precautions should be taken to reduce the injuries that can result from glass breakage by:  
a) selecting glass of a suitable type, thickness and size;  
©RSB 2023- All rights reserved                  4 b) enhancing a person’s awareness of presence of glass by making glass visible (manifestation of glass); 
and 
c) minimizing manual handling of large pieces of glass during installation. 
 
 
Key 
1) Doors (high risk) 
2) Door side panels (medium risk) 
3) Low-level glazed areas (low risk) 
Figure 1 —Critical locations in vertical glazing 
 
Table 1 — Type of glass suggested for use at different critical locations/cases in buildings 
 CASE 1 
Vertical walls with 
residual protection 
or 𝑯𝑺 ≥ 𝟎.𝟕𝟓 𝒎  
(not likely to be 
subjected to 
human impact) CASE 2 
Vertical walls 
𝑯𝑺< 0.75 𝑚 and 
𝑯𝒇 ≤ 𝟏.𝟓 𝒎 (Human 
impact but not risk 
of fall) CASE 3 
Vertical walls 
𝑯𝑺< 0.75 𝑚  and 
𝑯𝒇> 1.5 𝑚 (Human 
impact and risk of 
fall) CASE 4 
Horizontal or 
sloped glazing 
glass (risk of fall) CASE 5 
Glass acting as a 
balustrade/ railing 
(Human impact 
and risk of fall) 
5         
 
Tyes of 
glass Any Glassa) Safety Glass
Examples Please refer to note 
4; residual 
protection is the 
safeguard provided 
to avoid the impact 
of human being on 
glass. It is provided 
on the side of the 
glass where there 
are chances of 
human impact. It 
can be achieved by 
providing protection 
in the form of a sill 
structure or transom 
or chair rail or grill 
work inside a) Doors
b) Side panels
c) Glazed area
d) Doors in 
bathroom: Fully
framed, partially 
framed, 
frameless)
e) Façade
f) Windows
g) Internal partitions 
and doors
h) External façade 
and doors on 
ground floor, 
above floors with 
terrace outside
a) Safety glass is not mandatory 
b) Laminated float glass is preferred 
NOTE 1 ‘Hf' corresponds to “height of fall” of human being or glass in case of change in level and ‘Hs’ corresponds to the 
to floor height.  
NOTE 2 In case of mirror glazing, it should conform to the requirements of other safety glasses unless it is fully backed by a so
NOTE 3 In case 2 and 3, if the smaller dimension of the pane is 250 mm or less and its area is 0.5 
used, provided that its nominal thickness is not less than 6mm. (applicable to vertical glazi
NOTE 4 Toughened or laminated safety glass should meet respective test requirements as given in Table 3. 
5.3.5 The effective toughened safety glass thickness and/or laminated safety glass configuration shall be 
determined case by case with regard t
a) other solicitations (wind load, snow load, dead load, and human load);
b) the overall dimension (length, width of surface);
         ©RSB2023- All rights reserved 
 
Safety Glass  Safety Glassb) Laminated Safety 
Glass 
Doors 
Side panels  
Glazed area  
Doors in 
bathroom: Fully  
framed, partially 
framed, 
frameless)  
Façade 
Windows  
Internal partitions 
and doors  
External façade 
and doors on 
ground floor, 
above floors with 
terrace outside  a) Curtain walls 
b) Façade 
c) Spandrels 
d) High activity 
area 
e) High risk area 
f) To avoid risk a) Roof 
(Skylights)
b) Ceilings  
c) Bus shelters
d) Floors (not 
structural 
floors) 
e) Stairs 
f) Sloped façade
 
of human being or glass in case of change in level and ‘Hs’ corresponds to the 
2 In case of mirror glazing, it should conform to the requirements of other safety glasses unless it is fully backed by a so
3 In case 2 and 3, if the smaller dimension of the pane is 250 mm or less and its area is 0.5 m2 or less, glass other than safety glass may be 
used, provided that its nominal thickness is not less than 6mm. (applicable to vertical glazi ng).  
4 Toughened or laminated safety glass should meet respective test requirements as given in Table 3.  
The effective toughened safety glass thickness and/or laminated safety glass configuration shall be 
determined case by case with regard t o: 
other solicitations (wind load, snow load, dead load, and human load);  
the overall dimension (length, width of surface);  
DRS 397-5: 2023 
All rights reserved    
Laminated Safety Laminated safety 
glass 
(Skylights)  
 
Bus shelters  
Floors (not 
structural 
Sloped façade  a) Balustrades 
b) Balcony 
c) Railings 
of human being or glass in case of change in level and ‘Hs’ corresponds to the “sill height” with reference 
2 In case of mirror glazing, it should conform to the requirements of other safety glasses unless it is fully backed by a so lid material.  
or less, glass other than safety glass may be 
The effective toughened safety glass thickness and/or laminated safety glass configuration shall be 
 
©RSB 2023- All rights reserved                  6 
 c) the aspect ratio of the glass; and 
d) the glazing fixing type (framing, bolted system, structural system, etc). 
5.3.6 Precautions against chances of injuries due to broken glass falling on people include the following:  
a) broken annealed glass falling on people can cause grievous or even fatal injuries; hence it is 
recommended to use safety glass in locations other than defined in case 1 where the risk of people 
getting hurt by falling glass is high; 
b) toughened sheet safety (tempered) glass has a safe breakage pattern, as it breaks and disintegrates into 
small and relatively harmless particles. However thick toughened glass particles may stay interlocked, 
and fall as lumps of these multiple particles and can cause a minor or medium injury mainly due to the 
weight of the cluster; 
c) laminated sheet safety glass will generally not fall out of fixing. However, where laminated glass with both 
glasses toughened, used for horizontal or sloped glazing is used, in case of failure of both toughened 
glasses, it may crumble as a blanket and fall out of fixing. This factor needs to be considered while 
designing horizontal and sloped glazing; 
d) any broken glass in any glazing should be removed immediately on breakage; and 
e) strength of the glazing system should be such that it has the ability to hold glass in place and prevent it 
from falling out as a whole. 
5.3.7 In case of external laminated glass facades, openable portions have to be left at regular distances for 
firefighting and smoke exhaust. 
5.3.8 If Insulating Glass Unit (IGU) is used in situations mentioned in this standard, then one of the following 
will apply: 
a) if IGU is installed in areas subjected to human impact on either side, then both the panes of the unit shall 
meet the requirements of this standard.  
b) In situations where access is restricted to one side of the unit, then only the accessible side should meet 
the requirements of this standard. 
5.4 Manifestation (making glass visible) 
5.4.1 Presence of glass in a door, side panel or a panel capable of being mistaken for a doorway or 
opening, which is not made apparent by transoms, colonial bars, door frames, large door handles, stall or 
other components of glazing system or other decorative treatment, including being opaque or patterned, the 
glass should be marked to make it visible.  
5.4.2 The manifestation employed should be of a sufficient size to make it immediately obvious. The 
manifestation should preferably be permanent e.g., etching of the glazing; alternatively, if applied materials 
are used, they should be durable and not easily removed.  DRS 397-5: 2023 
7                ©RSB2023- All rights reserved 
 5.4.3 Marking shall be in the form an opaque band not less than 20 mm in height and located so that the 
vertical distance from the floor level is not less than 700 mm from the upper edge of the band and not more 
than 1200 mm to the lower edge of the band. 
5.4.4 The band shall be such that it is readily apparent and it can be achieved by contrasting the band with 
background or by increasing height of band. Safety glazing cannot be substituted by making the glass visible 
by marking.  
5.4.5 A band or marking is not required where any one of the following applies:  
a) height of the glass is not greater than 1000 mm at any part; 
b) the width of the glass is not greater than 500 mm at any part (this applies to overall panel assembly – not 
individual glass pieces as in faceted glazing); 
c) within 750 mm of the floor there is no glass; and 
d) the glass is provided with at least one fixed glazing bar, firmly attached to the styles to locate and protect 
each face of the glass. At least one transom (glazing bar) shall be located with its upper edge not less 
than 500 mm and its bottom edge not more than 1000 mm above the floor level. The glazing bar shall 
have a face width not less than 40 mm ± 3 mm.  
5.5.6 Alternatively, patterns may be used as an acceptable form of marking provided it meets the other 
criteria in this standard.  
5.5 Identificationof safety glass 
5.5.1 All Safety glasses shall be procured from certified manufacturers and the product shall conform to 
the requirements of relevant standards. Either a label that cannot be removed and reused or a permanent 
(indelible) mark on the glass surface shall mark all the panels of safety glass.  
NOTE Preferably, safety glass certified by an accredited certification body may be used. Manufacturer’s name, registered 
trademark or code of the manufacturer or supplier, type of safety glass, the standard number against which the safety 
glass has been tested and the grade of test classification are other commonly marked information. 
5.6 Test requirements 
5.6.1 Fragmentation test 
The fragmentation test shall be done in accordance with RS ISO 12543-2.  
5.6.2 Mechanical strength 
The required mechanical strength values (see Table 2) apply to quasi-static loading over a short time like wind 
loading relate to 5% probability of breakage at the lower limit and 95% confidence intervals. 
Table 2— Minimum mechanical strength required for fully toughened flat glass   
©RSB 2023- All rights reserved                  8 
 Type of glass Mechanical strength                               
N/Sq mm 
Flat(Clear / Tinted / Coated / Mirror) 120 
Enameled flat (Based on enameled 
surface in tension) 75 
Patterned glass 90 
 
If the glass satisfies the relevant impact test performance requirements (or fragmentation test for toughened 
glass), in addition to all other appropriate tests mentioned in available Indian Standards or as listed in Table 3 
below, these materials can be classified as safety glass. 
TABLE 3 — Test requirements  
Requirements against Laminated Safety glass Toughened Safety glass Test requirement as per 
Impact/Resistance to shock - 
Yes 
RS ISO 12543-4  
 Fragmentation Test - 
Yes 
Warp test - Yes 
Boil Test YES - 
Fracture and Adhesion test YES - 
Light stability test  YES - 
6 Safety related to glass handling, transportation and storage 
6.1 Glass handling and transportation safety considerations 
6.1.1 Workmen handling or moving glass pieces and waste glass pieces should be provided personal 
protective equipment including cut/slip resistant gloves and footwear (safety boots) when handling and 
transporting glass sheets  and safety glasses with side shields for eye protection when cutting. 
6.1.2 Glass should be inspected before moving it to assure there is no any damage that may cause 
spontaneous glass breakage to avoid injuries. DRS 397-5: 2023 
9                ©RSB2023- All rights reserved 
 6.1.3 Proper and safe lifting and moving techniques including holding the glass firmly in hands and not to 
carry glass over head or under arms should be used. 
6.1.4 When setting glass on the floor, or other any other surface, it should be gently placed down on the 
long edge and should not be placed directly on hard surfaces, instead, padding, or another type of cushioning 
agent can be used. 
6.2 Glass storage safety considerations 
6.2.1 Glass edges shall be covered or otherwise protection provided to prevent hand injuries to workers 
passing by.  
6.2.2 Waste glass pieces should be stored or disposed off in such a manner as to avoid injuries to 
workmen. 
6.2.3 Further glass sheets and plates should not be stacked horizontally nor one upon the other. These 
should be kept upright slightly slanting. 
6.2.4 The following are the safety considerations to avoid injuries/acidents: 
a) all storage areas should be free from slip/trip hazards; 
b) when storing glass on trolleys in a ‘static position’, ensure trolley braking devices are engaged and 
restraining bars are used; 
c) glass stored on frames should be evenly loaded on both sides of the frame; and 
glass should not be stacked against walls.    
©RSB 2023- All rights reserved                  10 
 Bibliography 
[1] RS ISO 16293-1: 2008 Glass in building — Basic soda lime silicate glass products — Part 1: Definitions 
and general physical and mechanical properties 
[2] RS ISO 16293-2: 2017 Glass in building — Basic soda lime silicate glass products — Part 2: Float glass 
[3] RS ISO 12543-1: 2011 Glass in building — Laminated glass and laminated safety glass — Part 1: 
Definitions and description of component parts 
[4] RS ISO 12543-2: 2011 Glass in building — Laminated glass and laminated safety glass — Part 2: 
Laminated safety glass 
[5] RS ISO 12543-3: 2011 Glass in building — Laminated glass and laminated safety glass — Part 3: 
Laminated glass 
[6]  
[7] RS ISO 12543-5: 2011 Glass in building — Laminated glass and laminated safety glass — Part 5: 
Dimensions and edge finishing 
[8] RS ISO 12543-6: 2011 Glass in building — Laminated glass and laminated safety glass — Part 6: 
Appearance 
[9] RS ISO 12540: 2017 Glass in building — Tempered soda lime silicate safety glass 
 DRS 397-5: 2023 
 
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